81) of SRPC held on 24th January, 2019

Minutes of the 81st Meeting of PCSC held on 24

th January, 2019 Page 1

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Minutes of the 81st Meeting of Protection Coordination Sub-Committee (PCSC – 81) of SRPC held on 24th January, 2019

1. Introduction

The 81st meeting of Protection Coordination Sub-Committee (PCSC-81) of SRPC was held on 24th January, 2019 at SRPC Secretariat, Bengaluru. The list of participants is enclosed at Annexure-I. Sh. S. R. Bhat, Member Secretary (MS), SRPC welcomed Members and Participants to the meeting and briefed them on the following points: Apprised Constituents that Protection Management System (PMS) project is under crucial

stage of execution since the data collection from various identified stations is nearing completion, and many significant activities that have a bearing on project completion, as mentioned below, are under progress:

Building & refining of SR-Network being constructed with the collected data.

Embedding of lower voltage network of all states into PMS Database.

Validation of the SR-Network being built with SCADA Data for a reference time instant (corresponding to peak demand of 2018)

Preparation of Protection SLD’s of the Stations covered as part of PMS project. Since completion of the above is critically dependent on co-operation of all SR-Constituents, he urged them to be pro-active, and extend all necessary co-operation so that the project comes into being from April, 2019. In this regard, he also intimated that User Manual of Protection Data Management System (PDMS) was circulated to all SR-Constituents vide SRPC letter dated 18.12.2018, and requested to furnish sought details for creating PDMS User Accounts of various SR-Constituents. He also stated that training on using various modules of Protection Data Management System (PDMS) would be imparted to SR-Constituents during March-April, 2019.

Remarked that details sought for creating DMNS User Accounts are still awaited from certain Organizations like HNPCL, SLDC-KPTCL, NTPC (Kudgi) & JSWEL, and requested them to furnish the same without further delay. Further since DMNS had been put into service w.e.f. 10.09.2018, he requested all SR-Utilities to start using the same to intimate further changes that have taken place (w.r.t. network & protection elements) at the stations falling under their control after PRDC field visits so that they can be incorporated in PMS database appropriately.

Stated that in view of observed delay in implementing New Protection Audit Recommendations by various Constituents, a review of their compliance status was proposed to be undertaken later in the meeting; and requested concerned Constituents to participate in that and spell out in clear-cut terms the reasons for the delay, and action plan for complying with them.



Stated that as decided in the 80th meeting of PCSC held on 20-21 December, 2018, it was proposed to modify the existing in-service SPS at 220 kV Kaiga GS as per the details shared vide Agenda of the meeting. He requested KPTCL, NPCIL (KGS) & SRLDC to present their viewpoints on the same when it is taken up for discussion later in the meeting.

2. Confirmation of the Minutes of the 80th meeting of PCSC held on 20th December, 2018

The minutes of the 80th meeting of PCSC were circulated vide SRPC letter No. SRPC/SE-III/ PCSC-80/ 2019/ 273-308 dated 09.01.2019. Since no comments had been received from any of the Constituents, the minutes of the 80th meeting of PCSC were confirmed.

3. Details of Grid Disturbances (GD’s), Grid Incidents (GI’s), and Line Trippings due to

Auto- Reclose (A/R) failure/ non-operation & PLCC mal-operation

The trippings due to GD’s, GI’s, A/R failure/ non-operation, and PLCC mal-operation that had

occurred during December, 2018 - January, 2019 were discussed in the Meeting. The deliberations and recommendations of the PCSC forum are enclosed at Annexure–II for needful action please. The details of the tripping events including relevant PMU plots presented by SRLDC in the meeting are also enclosed at Annexure-X for kind reference.

4. Status of implementation of pending PCSC Recommendations (P-REC)

The status of implementation of pending PCSC recommendations was discussed in the meeting.

The updated status of the same as on 14.02.2019 is enclosed at Annexure–III. The Constituents were asked to take steps to comply with the same, and requested to submit the status of their compliance latest by 15.03.2019.

5. Remedial measures/ Action taken for the tripping incidents of the transmission

elements under forced outage (PRM)

The tripping incidents of the transmission elements under forced outage for which the remedial

action taken had not been furnished were discussed in the meeting. The Constituents were asked to kindly furnish specific remedial measures/ action taken covering one or the other items from the following indicative list in time so as to forward the same to Central Electricity Authority:

Brief details of line patrolling carried out (with tower location)

Brief details of RoW maintenance (by proper Tree-cutting) resorted to

De-capped insulators replacement

DC earth fault removal

PLCC cards replacement

Relay settings modification

Steps taken to put A/R or CB into service after they have been locked-out

Faulty equipment replacement

Reference to OEM in case of equipment failure

Brief Details of tests carried out to ascertain the healthiness of various equipment (Power Transformer/ Reactors/ Surge Arrestors/ Circuit Breakers/ CT's/ PT's/CVT's) like Insulation Resistance (IR) test, Winding Resistance test, Capacitance test, Tan delta test, DGA test, Leakage current test, CRM/ DCRM test, etc.

Any other appropriate remedial measure



The updated list of PRM as on 13.02.2019 is enclosed at Annexure-IV for appropriate action by the Constituents.

6. Certificate on Healthiness of Batteries

As per MoP/ CEA direction given in pursuant to recommendations of the Enquiry Committee (NEW Grid Disturbance on 30th & 31st July, 2012), RPC’s are required to obtain from their respective Constituents a monthly certificate for healthiness of batteries installed at 220 KV & above voltage level Substations (for power supply to Relays, RTUs and PLCC equipment) and furnish the same to CEA/ MoP. With reference to above, the Constituents were requested to submit the certificate on healthiness of batteries on monthly basis (i.e. status for a month shall be sent by the 7th day of the following month) to SRPC as per the format given below:

Sl. No.

Station Application Battery Battery Charger Remarks

Station Name

Code Type

(PS/ SS)

Protection/

Communication

Details Status (Healthy/ Unhealthy)

Details Status (Healthy/ Unhealthy)

Brief Details of unhealthy battery banks and/ or DC leakage along with proposed time-lines for rectifying the same shall be mentioned.

1 Station-A Protection (Bank-1)

Protection (Bank-2)

Communication (Bank-1)

Communication (Bank-2)

2 Station-B …

… … …

Note: 1. Code is the short name of the Station 2. PS – Power Station; SS – Substation

The sought status for the month of December, 2018 had not been received from the following SR-Constituents: KPTCL & TPCIL

7. Review of in-service Special Protection Scheme (SPS) at 220 kV Kaiga GS of M/s NPCIL

During deliberations in 80th PCSC Meeting held on 20.12.2018 on the GD leading to complete outage of 220 kV Kadra and 220 kV Kodasalli Power House of KPCL and 220 kV Karwar SS of KPTCL on 13.11.2018 at 16:56 hrs, the appropriateness of the existing SPS at 220 kV Kaiga GS (as given below) to effect tripping of 220 kV Kaiga GS – Kadra PH line and 220 kV Kaiga GS – Kodasalli PH line, instead of effecting generation back-down at source nodes (220 kV Kadra PH and 220 kV Kodasalli PH) was discussed.



********************************************************************* Exiting SPS at 220 kV Kaiga GS:

Installed Capacity of 220 kV Kadra PH: 3 x 50 MW

Installed Capacity of 220 kV Kodasalli PH: 3 x 40 MW Installed Capacity of Kaiga GS: 2 x 220 MW (220 kV) + 2 x 220 MW (400 kV)

Rating of each of the two ICT’s at kV Kaiga GS: 400/ 220 kV, 500 MVA During non-availability of one of the ICTs at Kaiga GS, If the power flow in the other ICT (in service) is more than 500MW and less than 550 MW, there is an

alarm If the power flow in the other ICT (in service) is more than 550 MW for 2 sec, then

220 kV Kaiga GS – Kadra PH line and 220 kV Kaiga GS - Kodasalli PH line will be tripped from 220 kV Kaiga GS end.

******************************************************************* It was agreed that the existing SPS should be revised to give priority to effect generation back-down at Kadra PH and Kodasally PH compared to tripping 220 kV evacuating lines; and SRLDC was asked to carry out relevant studies and present revised SPS in the next PCSC meeting for discussion & approval. In this regard, the necessary system studies carried out by SRLDC are enclosed at Annexure-V. From the studies, the following can be concluded:

If one ICT at Kaiga is out of service and 220 kV Nagkheri - Kodasalli lines - 1 & 2 are under idle charged condition and generation at Kaiga GS is full, then Flow in the in-service ICT at KGS can go up to 600 MW, if generation is full at 220 kV Kadra PH &

220 kV Kodasalli PH. For reducing the flow in the in-service ICT to 500 MW under above conditions, generation

reduction of around 100 MW (264 MW-158 MW= 106MW) is required in total from Kodasalli PH and Kadra PH.

Since the installed capacity of Kadra PH is 3x50 MW and Kodasalli PH is 3x40 MW, in view of above study results, it was agreed to distribute this quantum of generation reduction to 50 MW at Kadra PH and 40 MW at Kodasalli PH. It was also agreed to incorporate above logic at an intermediate power level of 530 MW so that necessary SPS signals can be transmitted via PLCC from Kaiga GS to Kadra PH and Kodasally PH. Accordingly, it was agreed to modify the existing SPS at Kaiga GS as given below: *********************************************************************************** Proposed SPS at 220 kV Kaiga GS: During non-availability of one of the ICTs at Kaiga GS,

Stage-I: If the power flow in the other ICT (in service) is more than 500MW and less than 530 MW, then a signal will be generated to give ALARM locally at Kaiga GS (same as in existing SPS).

Stage-II: If the power flow in the other ICT (in service) is more than or equal to 530MW and less than 550 MW, then suitable SPS signals will be generated at Kaiga GS end, and are transmitted through PLCC to Kadra PH and Kodasally PH using which the latter will effect automatic generation reduction of about 50 MW (by tripping the identified running Unit) at Kadra PH and of about 40 MW (by tripping the identified running Unit) at Kodasalli PH (additional logic to be incorporated)

Stage-III: If the power flow in the other ICT (in service) is more than or equal to 550 MW for 2 sec, then 220 kV Kaiga GS – Kadra PH line and 220 kV Kaiga GS - Kodasalli PH line will be tripped from 220 kV Kaiga GS end (same as in existing SPS).

***********************************************************************************



In this regard, NPCIL (Kaiga GS), KPTCL, and KPCL are requested to (i) kindly furnish the action plan for implementing the above modified SPS, and (ii) take necessary steps to implement the same at the earliest.

In this regard, the following were also noted: The above modified SPS would come to rescue if only there is sufficient time available before

the power flow across the only in-service ICT at Kaiga GS reaches to 550 MW from 500 MW. The reliability of the proposed generation reduction measure at Kadra PH and Kodasalli PH is

dependent on the healthiness of PLCC channels between Kaiga GS & Kadra PH and Kaiga GS & Kodasalli PH.

The chances of above modified SPS progressing from Stage-I to higher Stages can be avoided by ensuring proper coordinating mechanism between Kaiga GS and Karnataka-SLDC so that timely instructions from the latter are given to Kadra PH & Kodasally PH for effecting required generation reduction.

8. Review of Compliance Status of New Protection Audit Recommendations

As part of GSC (Task-II) under Package-A, protection audit check of 15 stations was carried out by

M/s Tractebel Engineering (TE) in the southern region during the period, December, 2015 – July, 2016. Subsequently, protection audit of various stations in SR is also being regularly conducted by SRPC teams in line with CERC Order dated 27.04.2015 in respect of APTRANSCO Petition No.95/MP/2015 and CERC Order dated 14.05.2015 in respect of TSTRANSCO’s Petition NO:83/MP/2015. So far, protection audit of 15 stations was carried out during the period December, 2016 – December, 2018.

The compliance status of the recommendations given was reviewed in the 81st meeting of PCSC

held on 24.01.2019. The list of Stations audited & compliance % of the recommendations as on 31.01.2019 is given below:

Sl. No. Name of the Station Period of

Protection Audit

Total no. of Recommendation

s given

Total no. of Pending

Recommendations

Compliance %

APTRANSCO 61.54

1 400/ 220 kV Narnoor SS

16–18

February, 2016 31 11

64.51 2 400/ 220 kV

Uravakonda SS 5-6 April, 2018 21 9

57.14 TSGENCO (Thermal) 57.75

1 (i) 220 kV KTPS (O&M) 14-16 March, 2016

36 17 52.77

1 (ii) 220 kV KTPS (Stage-V) 14-16 March, 2016

22 12 45.45

1 (iii) 220 kV KTPS (Stage-VI) 14-16 March, 2016

13 1 92.31

TSTRANSCO 28.13

1 400/ 220 kV Shankarapally SS

20-21 March, 2017

11 2 81.81

2 400/ 220-132 kV Gajwel SS

30-31 October, 2018

21 21 00.00 (Not yet

informed)



KPCL 53.64

1 400 kV & 220 kV Raichur TPS

8-10 June, 2016 41 22 46.34

2 220 kV Nagjheri PH 14-16 July, 2016

31 13 58.06

3 220kV Sharavathy GS 30-31 October, 2017

16 8 50.00

4 400 kV Yermarus TPS 28-29 August, 2018

22 8 63.63

KPTCL 65.31

1 400/ 220 kV Guttur SS 4-6 May, 2016 43 7 83.72 2 400/ 220 kV

Nelamangala SS 8–10 February, 2016

35 13 62.86

3 400 kV Bellary Pooling Station

27 August, 2018

20 14 30.00

KSEBL 55.81

1 220 kV Edamon SS 18-20 January, 2016

43 19 55.81

TANTRANSCO 55.88

1 400/ 230 kV Alamathy SS

4-6 January, 2016

31 11 64.52

2 230 kV Alundur SS 17 December, 2016

16 8 50.00

3 400/ 230 – 110 kV Palavadi SS

14-15 May, 2018

21 11 47.62

Puducherry ED 11.60

1 230/ 110 kV Villianur SS

10 July, 2017 31 27 12.90

2 230/ 110 kV Bahour SS

11 July, 2017 38 34 10.53

PGCIL (SR-I) 60.71

1 400 kV & HVDC Gazuwaka SS

28-30

December, 2015

8 2

75.00 2 400/ 220 kV Gooty SS 12th,13th and

15th February, 2016

8 3

62.50 3 765/ 400 kV Nellore

PS 19-20 June, 2017

5 1 80.00

4 765/ 400 kV Maheshwaram SS

8-9 February, 2018

7 5 28.57

PGCIL (SR-II) 61.90

1 400 kVHosur SS of PGCIL (SR-II)

9-11 December, 2015

4 3

25.00 2 400 kV Tirunelveli SS 8th, ,9th and 11th

January, 2016 8 4

50.00 3 400 kV Alundur SS 16 December,

2016 4 0

100.00 4 400/ 220 kV

Kozhikode SS 21-22 December, 2017

5 1

80.00



NTPC 92.50

1 400 kV Ramagundam STPS

18-20 February, 2016

40 3 92.50

NPCIL 12.50

1 220 kV Kaiga GS 4-6 April, 2016 6 2 66.66 2 400/ 230 kV

Kudankulam NPP 10-11 December, 2018

26 26 00.00 (Not yet

informed) NLCIL 65.63

1 400 kV NLC TPS-II Station

8–10 February, 2016

32 11 65.63

The compliance status of New Protection Audit Recommendations as reviewed in the meeting is given at Annexure-VI for kind reference.

APTRANSCO, TSGENCO, TSTRANSCO, KPCL, KPTCL, KSEBL, TANTRANSCO, Puducherry ED, NTPC (RSTPS), NPCIL, NLCIL, PGCIL (SR-I) & PGCIL (SR-II) are requested to kindly take suitable action to comply with their respective pending remarks.

9. Operationalization of Data Modification Notification System (DMNS) for the States of

Southern Region

On the above subject, SRPC vide (i) letter no: SRPC/ SE-III/ PMS/ 2018/ 5124 – 146 dated 03.08.2018 & subsequent reminder mails, and (ii) letter no: SRPC/ SE-III/ PMS/ 2018/ 7242-62 dated 16.11.2018 & subsequent reminder mails had requested the Utilities of Tamil Nadu & Puducherry & Kerala & Telangana and Andhra Pradesh & Karnataka respectively to furnish the details of their Users who are responsible for calculating relay settings and/ or intimating calculated relay settings to the field to SRPC Secretariat ([email protected]) so as to create their respective DMNS Accounts. However, it is noted with concern that details in this regard are still awaited from the following Utilities:

Karnataka-SLDC, HNPCL, Lanco KPL, NTPC-Kudgi, & JSWEL Since DMNS has already been operationalised w.e.f. 10.09.2018, it is requested from the above Utilities to kindly furnish the sought details without further delay.

In this regard, it is also requested from all Utilities (including SLDC’s) of Tamil Nadu, Kerala, Telangana, Puducherry, Andhra Pradesh, Karnataka & SRLDC to regularly use DMNS application for intimating further changes that have taken place at the stations falling under their control for incorporating the same in PMS database.

In this regard, the following were also clarified. Since data collection activities have covered all identified stations as per scope of PMS

project (these are basically all 220 kV & above Substations including Wind/ Solar Pooling Stations and all 132/ 110/ 66 kV & above Generation Switchyards spread across southern region) commissioned up to 31.12.2018, all SR-Constituents are requested to use DMNS application for intimating further changes (element-wise) that would take place at these stations (after PRDC site visits) to incorporate them appropriately in PMS Database (Network Database of PSCT & Relay Settings Database of PDMS).

mailto:[email protected]



For the new Stations that would up from 01.01.2019, all SR-Constituents are requested to use the following formats for intimating all details pertaining to those stations:

For Stations other than Wind & Solar: Annexure-VII

For Wind Pooling Stations : Annexure-VIII

For Solar Pooling Stations : Annexure-IX

10. Network Configuration Changes

As per the information furnished by SR-Constituents to the OCC forum in their 151st meeting

held on 10.01.2019 (Minutes circulated vide SRPC letter dated 04.02.2019), it is informed that the following network configuration changes (additions/ deletions/ modifications of transmission elements) took place in the southern grid during December, 2018:

400 kV Talaricheruvu SS ICT-I in Ananthapur district of 315 MVA Capacity was commissioned on 17.12.2018 by APTRANSCO.

LILO of 400 kV SCCL-Gajwel Circuit-I at Ramadugu SS in Karimnagar district of 36 Ckm was commissioned on 14.12.2018 by TSTRANSCO.

220 kV D/C Line from 400/220 kV SS Julurupadu to 220/132/33 kV SS Pedagopathi I & II in Khammam district of 90 Ckm was commissioned on 01.12.2018 by TSTRANSCO.

220 kV D/C Line from Sithapuram to Huzurnagar in Suryapet district (58.62 Ckm) was commissioned on 05.12.2018 by TSTRANSCO.

220 kV D/C Line from LILO of Chillakalu – Narketpally to Huzurnagar in Suryapet district (24.61 Ckm) was commissioned on 05.12.2018 by TSTRANSCO.

220/132/33 kV SS Pedagopathi I & II in Khammam district of 200 MVA capacity was commissioned on 01.12.2018 by TSTRANSCO.

220/132/33 kV SS Huzurnagar I & II in Suryapet district of 200 MVA capacity was commissioned on 10.12.2018 by TSTRANSCO.

220/33 kV features at existing 220 kV Nagaram in Warangal district was commissioned on 20.12.2018 by TSTRANSCO with augmented capacity of 31.5 MVA.

315 MVA ICT at Sundilla SS ICT II Peddapalli District of 315 MVA Capacity was commissioned on 24.12.2018 by TSTRANSCO

2 Nos 400/11 kV PTRs at Medaram GIS in Karimnagar district of 320 MVA Capacity was commissioned on 28.12.2018 by TSTRANSCO.

11. Instances of SPS Operation

Based on the information furnished by SRLDC, it is informed that no SPS operations took place in SR during the period 20.12.2018 – 23.01.2019.

12. Status of Implementation of Protection Audit Recommendations (Phase-I & Phase-II)

With reference to the Petitions filed by KSEB (88/MP/2016) and KPTCL (135/MP/2016) seeking further time-extension for completing their respective Protection Audit Recommendations (PAR), the final Order of Hon’ble CERC disposing of petitions was issued on 15.12.2016. In this Order, the Commission, apart from granting last-chance time-extensions to various SR-Constituents, had also directed SRPC to monitor the status of completion of PAR regularly in PCSC meetings and submit bi-monthly report to the Commission confirming the completion of Phase-I and Phase-II of PAR of the Constituents of Southern Region.



In this regard, based on the information furnished by various Constituents, a summary table showing the compliance status of various SR-Constituents as on 14.02.2019 is given below:

Sl. No.

Constituent

PAR (Phase-I) Activities

PAR (Phase-II) Activities

PAR (Ph-I & Ph-II) Compliance (%)

Remarks

Stipulated

Completion Date

Stipulated

Completion Date

1 APGENCO (Hydel)

31.12.2017 31.12.2017 93.33 Based on the status furnished, the lone pending recommendation is expected to be completed by 28.02.2019

3 APTRANSCO 31.03.2017 --- 98.57 Based on the status furnished, the lone pending recommendation is expected to be completed by 31.05.2019.

4 TSGENCO (Hydel)

31.03.2017 31.03.2017 91.18 Based on the status furnished, timeline for complying with the remaining pending recommendations (3 in no.) is 31.03.2019.

5 TSTRANSCO 31.03.2017 31.03.2017 93.18 Based on the status furnished, timeline for complying with the remaining pending recommendations (6 in no.) is 31.03.2019.

6 KPTCL 31.05.2017 31.05.2017 88.73 Based on the status furnished, timeline for complying with the remaining pending recommendations (8 in no.) is 30.04.2019.

7 TANGEDCO 31.12.2017 31.12.2017 91.67 Based on the status furnished, timeline for complying with the remaining pending recommendations (3 in no.) is 31.03.2019.

8 TANTRANSCO 31.12.2017 31.12.2017 77.27 Based on the status furnished, timeline for complying with the remaining pending recommendations (30 in no.) is 31.03.2019.

9 KSEBL 30.11.2016 31.12.2017 97.4 Based on the status furnished, the lone pending recommendation is expected to be completed by 31.03.2019.

10 NPCIL (MAPS) 31.01.2017 --- 88.89 Based on the status furnished, timeline for complying with the lone pending recommendation is 31.03.2019.

* The Constituents - APGENCO (Thermal), TSGENCO (Thermal), KPCL, PGCIL (SR-I & SR-II), NTPC, NLC – have fully complied with the protection audit remarks given to their respective Stations.



It may be noted that the total compliance percentage of SR-Constituents including IPP’s in completing Protection Audit Works as on 14.02.2019 stands at 91.64.

All above SR-Constituents are requested to complete their respective pending PAR at the earliest. The IPP’s for whom there are pending PAR *viz., Spectrum PGL, Konaseema GPL, APGPCL Vijjeswaram (Stage-I & Stage-II), & LANCO-Kondapalli PL] are also requested to complete them at the earliest.

13. Nomenclature for naming various files uploaded in web-based Tripping Monitoring

System of SRLDC Portal

The nomenclature to be followed by the Constituents in naming various files (FIR, DR, EL, TR) corresponding to a tripping incident was brought out in the SRPC letter No. SRPC/ SE-III/ PCSC-45/ 4609 – 649 dated 26.06.2015 and in the minutes of PCSC-45 issued vide SRPC letter No. SRPC/SE-III/ PCSC-45/ 2015/ 5422-455 dated 21.07.2015. As illustrated therein, the format to be followed for the user entered part-name is given below:

Transmission Element File Name to be given by the user

Transmission Line SSN_DSN_line#_FT

Inter-connecting Transformer SSN_ICT#_FT

Generating Transformer SSN_GT#_FT

Generating Unit SSN_Unit#_FT

Where, SSN = Source Station Name/ From end Station Name/ Sending end Station Name DSN = Destination Station Name/ To end Station Name/ Receiving end Station Name FT = File Type (FIR/ DR/ EL/ TR)

All SR-Constituents are requested to kindly intimate the above file naming nomenclature to all the concerned and ensure that it is strictly followed at all the stations in their respective control areas so that tripping analysis can be done systematically.

14. Date & Venue of the next PCSC Meeting

It is informed that the 82nd meeting of PCSC will be held on 28th March, 2019 from 10:30 hrs onwards in the Conference Hall of SRPC Secretariat, Bengaluru.

*****

Annexure-I

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Annexure-I

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Annexure-I

Page 3 of 6

Annexure-I

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Annexure-I

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Annexure-I

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Grid Occurrences discussed in the 81st Meeting of PCSC held on 24th January, 2019 1/ 15

Analysis of Grid Occurrences - 81

I. Details of Grid Disturbances:

Sl. No.

Details of Event Date &Time Reason Remarks Category

1 Complete Outage of 230kV Siruseri SS of TANTRANSCO

09-01-2019 at 05:39 Hrs

230kV Bus-1 Bus-Bar Protection (BBP) mal-operated during Y-phase fault in 230 kV Siruseri Sholinganallur line. 230 kV Siruseri SS was under single bus operation, hence operation of Bus-bar protection resulted in tripping of all elements resulting in the complete outage.

Load Loss: 75MW

GD-1

SLD:

The single line diagram of 230/ 110 kV Siruseri SS as furnished by TANTRANSCO is attached at the end.

Connectivity Diagram:

Bus configuration and arrangement:

The station was on Single-Bus operation. Antecedent conditions:

Tripping of 230kV Siruseri – Sholiganallur (Ottiyampakkam) line: Siruseri (TANTRANSCO) end:

As per FIR/ DR/ EL/ TR, line tripped (in Y-ph) at 05:39:40.482 hrs on Y-E fault due to DPR, Z1 (A/R; 7.796kA) operation. However within 50 msec into A/R dead-time, BBP operated for 230 kV Bus resulted in 3-ph tripping of the line.

It was stated in FIR that the Y-ph fault was due to flashover of Y-ph suspension insulator at Location 10 in the line.

Sholiganallur (TANTRANSCO) end:

As per FIR/ DR/ EL/ TR, line tripped (in Y-ph) at 05:39:40.487 hrs on Y-E fault due to DPR, Z1 (5.58kA) operation, and successfully auto-reclosed after a dead-time of 0.6 sec. However, within 100 msec into A/R reclaim time, the line tripped in 3-ph on R-Y fault due to DPR, Z1 operation.

Annexure-II


Outage of 230/ 110kV Siruseri SS:

As per FIR/ TR, complete outage of the sation occurred at 05:39 hrs due to BBP relay (ABB make; RADHA) relay operation. It was stated that BBP relay had operated for a through fault (Y-E fault) in the 230 kV Ottiyambakkam feeder, which in turn was due to Y-phase suspension insulator flash-over at Location 10.

Deliberations:

It was noted that complete outage of the 230 kV Siruseri SS occurred primarily due to station being on single-bus operation. When enquired about the same, TANTRANSCO informed that steps are being taken to provide double-bus operation by replacing the existing static BBP relay (ABB, RADHA) with Numerical BBP (NR make) with two zones. Related works are targeted to be completed in 3 months.

When enquired about the reasons for BBP relay operation for a through fault, TANTRANSCO informed that they were suspecting stability issues with BB protection since the remote end station (230 kV Ottiyapakam) had recently been upgraded to 400 kV (Sholinganallur) SS. As a remedial action, the following were performed: BBP Relay Panel wiring was checked on 09.01.2019. Stability if the BBP relay for through faults was checked & ensured by increasing series

resistance. Its sensitivity was also proposed to be further corrected by revising (calibrating) the setting of shunt resistor in a week’s time.

When enquired about the reasons for keeping A/R dead-time as 0.6 sec, TANTRANSCO informed that it was due to old PD relays which do not allow A/R dead-time to be kept more than 0.6. TANTRANSCO informed that these old PD relays would be replaced with new & proper PD relays in 3 month time, when A/R dead-time would also be set to 1 sec uniformly across all feeders.

II. Details of Grid Incidents:

Sl. No. Details of Event Date &Time Reason Category

1 Tripping of 400 KV Mahboobnagar-Uravakonda line-1

04-12-2018 at 09:57 hrs

Mal-operation of relay due to improper GOOSE signal messaging caused tripping at Uravakonda & direct Trip sent to Veltoor end.

GI-2

Mehboobnagar (TSTRANSCO) end:

As per FIR/DR/EL, line tripped at 09:56:57.907 hrs due to DT receipt from the remote end. [PLCC counter increment in DT indicated]

Uravukonda (APTRANSCO) end :

As per FIR/EL, line tripped at 09:57:04.012 hrs due to mal-operation of GOOSE signal messaging and DT was sent to remote end. [PLCC TX increment was indicated]

DR/TR not furnished. When enquired about the reasons for line tripping, APTRANSCO informed that on 04.12.2018 LC

was availed for ICT-1 at Uravukonda end. ICT -1 and Uravukonda-Mehaboobnagar Line-1 were in the same dia. While hand tripping (Main-CB & Tie-CB) ICT-1, DT was extended to Mehaboobnagar end. On investigation, it was found that the feeder had tripped due to problem in Goose signal messaging. As remedial action, Goose signaling scheme was replaced with hard-wiring on 06.12.2018.

Annexure-II


2 Tripping of HVDC Talcher-Kolar Pole-1

12-12-2018 at 19:41 hrs

Pole-1 got tripped at Kolar end on transformer protection due to operation of Bucholz alarm in Y-phase converter transformer. Pole-2 went into metallic return mode after the tripping of pole-1 with power flow of 880MW

As per FIR/DR/EL/TR Talcher-Kolar Pole-1 tripped at 19:41:08.817hrs on operation of Buchholz alarm in converter transformer.

As per Tripping Report furnished by PGCIL (SR-II):

Annexure-II


It was noted that similar incident had also happened on 09.09.2018 at 07:45 hrs (the event was discussed in PCSCM-79 held on 25.10.2018 when the following was noted:

When enquired about the reasons for Buchholtz’s trip in the instant case, PGCIL (SR-2) informed

that they were suspecting issues with the Y-phase Converter Transformer of Pole-1 since such accumulation of gas in the converter transformer tank was being observed in the recent past without proper reason. As remedial action, it was informed that the faulty Y-ph Converter Transformer of Pole-1 would be replaced with spare by 05.02.2019.

In this regard, SCADA plots of Talcher-Kolar Poles – 1 & 2 power flow in MW were noted as follows:

When enquired about the reasons for non-actuation of any of the SPS’s (SPS-1 signal & SPS-2

signal), PGCIL (SR-II) informed that the quantum of power loss required to actuate SPS-1 & SPS-2 had not occurred during the sampling intervals of 2 sec. The report furnished by PGCIL (SR-II) vide their mail dated 28.01.2018 in this regard is given below:

Annexure-II


3

Tripping of 400 kV Vemagiri-Satenapalli

13-12-2018 at 21:48 hrs

Line tripped on operation of over-voltage stg-1 protection at Vemagiri and direct trip was received at Satenapalli. DR of Vemagiri end was not furnished to validate the over voltage operation.

GI-2

Sender and Receiver end FIR could not be downloaded in pdf format (SRLDC to address the issue). OVR-I gradings at 400kV Vemagiri:

Sattenapalli (APTRANSCO) end :

As per FIR/DR/EL/TR, line tripped at 21:48:20.909 hrs on receipt of DT from remote end [Vr=249.492V, Vy=248.725V, Vb=248.113V].

Vemagiri (APTRANSCO) end:

As per FIR/EL/ TR, the line tripped at 21:47:57.823 hrs due to OVR-I Operation (OVR grading = 109%, 4sec) and DT was sent to remote end [PLCC D/T TX counter increment indicated].

DR not furnished.

In EL, OVR-I_START was not observed due to which orderliness of the tripping w.r.t. stipulated OVR-I gradings could not be verified.

Remedial Action informed by APTRANSCO: As per mail dated 17.01.2019, APTRANSCO informed that Main-2 relay (which operated for OVR

Stage-I protection) was tested for Over voltage Stage-I protection duly availing Line clear on 19.12.2018 and it is identified that the relay is operating properly according to adopted settings

Annexure-II


and the reset to pickup ratio is more than 0.97. The line CVT Voltages were also measured & compared with that of adjacent line CVT,

connected Bus CVT and results found satisfactory.

When enquired about the reasons for not furnishing of DR, APTRANSCO informed OVR-I was enabled in Main-2 (REL-516) relay, and the relay has issues in generating DR. To this, PCSC forum had suggested APTRANSCO to enable OVR-I protection in Main-I relay, since it’s drop-off to pick-up ratio, as claimed by APTRANSCO, is observed to be good (~0.98).

In this regard, SRLDC was also asked to include in their preliminary reports the orderliness of OVR

trippings from the perspective of stipulated OVR-I gradings.

4 Tripping of 400 kV KTPS-7 – Julurupadu line-1

16-12-2018 at 00:30 hrs

Line tripped on operation of Over Voltage Stage-1 at Julurpadu end and DT received at KTPS-VII end. From DR: Vr=247kV, Vy=249kV and Vb=247kV. The voltage recorded in DR is observed to be less than O/v stg-1 pickup threshold considering drop off to pickup ratio of 98%.

GI-2

FNN not followed by TSGENCO OVR-I gradings at 400kV Julurupadu:

*** A = 111%, 10sec. KTPS (TSGENCO) end:

As per FIR/DR/EL/TR, line tripped at 00:30:59.928hrs due to DT receipt from remote end.

DR furnished was not a proper one. Names of Analog & Digital signals were not shown. Julurupadu (TSTRANSCO) end:

As per FIR/DR/EL, line tripped at 00:30:59.907hrs due to OVR-I (Tov = 5sec) operation. [Vr=247.703V, Vy=248.927V, Vb=247.06V]

OVR-I_Trip signal was not observed in DR.

TR not furnished.

The tripping was not as per stipulated gradings.

Remedial Action informed by TSTRANSCO: The Over Voltage settings at Julurupadu end were of old settings and not been revised. The

Over Voltage settings are revised on 24-12-2018. TSTRANSCO also informed that Drop-Off to Pick-up ratio of D60 was corrected to 0.978 on

04.01.2019.

Annexure-II


5 Tripping of 400kV KTPS-7 – Julurupadu line-2

16-12-2018 at 2:14 hrs

Line tripped on operation of Over Voltage Stage-1 at Julurupadu end and DT received at KTPS-VII end. From DR: Vr=246kV, Vy=248kV and Vb=245kV. Voltages recorded in DR are observed to be below O/v stg-1 threshold value considering pickup to drop off ratio of 98%.

GI-2

FNN not followed by TSGENCO OVR-I gradings at 400kV Julurupadu:

*** A = 111%, 10sec.

KTPS (TSGENCO) end:

As per FIR/DR/EL/TR, line tripped at 02:14:33.558 hrs on receipt of DT from remote end.

DR furnished was not a proper one. Names of Analog & Digital signals were not shown. Julurupadu (TSTRANSCO) end:

As per FIR/DR/EL, line tripped at 02:14:33.538 hrs due to OVR Stage-I operation. (Tov = 8sec) [Vr=246.574V, Vy=247.717V, Vb=244.96V] (OVR grading -110%, 8sec).

OVR-I_Trip signal was not observed in DR.

TR not furnished.

The tripping was not as per stipulated gradings.

Remedial Action informed by TSTRANSCO: The Over Voltage settings at Julurupadu end were of old settings and not been revised. The

Over Voltage settings are revised on 24-12-2018. TSTRANSCO also informed that Drop-Off to Pick-up ratio of D60 was corrected to 0.978 on

04.01.2019. In this regard, SRLDC was also asked to include in their preliminary reports the orderliness of OVR

trippings from the perspective of stipulated OVR-I gradings.

6 Tripping of 400 kV Suryapet - Julurupadu line-2

17-12-2018 at 00:15 hrs

Line tripped on operation of over-voltage stg-1 protection at Suryapet and direct trip was received at Julurupadu. DR of Suryapet end was not furnished to validate the over voltage operation.

GI-2

OVR-I gradings at 400kV Suryapet:

*** G = 109%, 6 sec. It was noted that 400 kV Julurupadu – Shankarapalli line-2 and 400 kV Julurupadu – KV Kota line-2

had been under outage in the antecedent conditions.

Julurupadu (TSTRANSCO) end:

As per FIR/DR/EL, line tripped at 00:59:01.541 hrs due to receipt of DT from the remote end.

Annexure-II


TR not furnished. Suryapet (TSTRANSCO) end:

As per FIR/EL, line tripped at 00:58:55.255 hrs on operation of OVR-I (Tov = 6sec) operation.

DR/ TR not furnished. When enquired about the reasons for not furnishing DR at Suryapet end, TSTRANSCO informed that

at Suryapet end, DR was not triggered since the D60 relay had not been not configured to trigger DR at the time of tripping event. TSTRANSCO assured that the issue would be attended within two weeks.

7 Tripping of 400 kV Kalpaka - Asupakka line-1

17-12-2018 at 10:32 hrs

Line tripped on operation of over voltage stg-1 protection at Asupaka and direct trip was received at Kalpaka. Voltage difference was observed between R, Y & B phases (R-254kV, Y-245kV, B-236kV)

GI-2

OVR-I gradings at 400kV Asupaka:

*** D = 110%, 8 sec.

Kalpaka (APTRANSCO) end:

As per FIR/DR/EL, line tripped at 10:30:28.496 hrs due to receipt of DT from the remote end.

TR not furnished. Asupaka (TSTRANSCO) end:

As per FIR/EL, line tripped at 10:31:48.026 hrs due to OVR-I (Tov= 8 sec) operation.

From DR, the voltages were observed as Vr= 254.15V, Vy=245.04V, Vb=236.57V.

Time sync issues between Kalpaka and Asupaka to be resolved. In this regard, similar incident that occurred on 08.08.2018 at 01:07 hrs (and discussed in PCSCM-78

held on 25.10.2018) was noted when TSTRANSCO informed the following:

It was noted that setting right of transposition issues on the line are yet to be attended by

TSTRANSCO; accordingly, TSTRANSCO was asked to expedite the same.

Till such time, TSTRANSCO was asked, as a temporary remedial measure, to use that Ph-N voltage as Voltage Input to OV relay (functionality), which corresponds closely with the grid voltage under over-voltage conditions such as those present during the instant tripping.

Annexure-II


8 400/200 kV ICT-3 at Vemagiri (AP)

17-12-2018 at 17:46 hrs

ICT-3 LV Breaker tripped due to DC earth fault

GI-2

ICT-3 Vemagiri (APTRANSCO) end:

As per FIR ICT-3 tripped on LV side at 17:46hrs due to DC leakage between Isolator and Control panel.

DR/ EL/ TR not furnished. When enquired about the reasons for ICT-3 tripping, APTRANSCO informed that upon investigation,

the control wiring insulation in breaker control cubicle had been found to be in damaged condition; and the same was rectified on 22.12.2018.

In this regard, similar tripping of ICT-3 that occurred on 04.10.2018 at 11:32 hrs was noted. For this

incident, cause of the tripping & remedial action taken were stated as below: • ICT-3 LV CB got tripped due to suspected DC earth fault. • As a remedial measure the faulty breaker control cable replaced with armoured cable on

04/10/18. From above, it was seen that ICT-3 trippings at Vemagiri were occurring primarily on account of

faulty/ damaged control cables of its CB; accordingly, APTRANSCO was asked to check the healthiness of control cables of all ICT’s breakers at their 400 kV Vemagiri SS, and take appropriate action as deemed fit.

9 Tripping of 220 kV Yerandahalli - Hosur line

22-12-2018 at 00:58 hrs

Line tripped-EFR enabled in Main-1 relay at Yerandahalli end. Line was holding from Hosur

GI-1

Hosur (TANTRANSCO) end:

As per FIR/TR, the feeder was kept holding from Hosur end. Yeranandahalli (KPTCL) end:

As per FIR/DR, line tripped at 01:00:53.797 hrs due to operation of Earth fault (In>3) protection.

DR legend corresponding to EF trip to be properly named.

When enquired about the reasons for In> 3 operation, KPTCL informed that the tripping was due to incorrect settings adopted for VT Fuse Fail logic in P444 relay (E/F operation time delay was kept as 0msec instead of the correct 500msec).

KPTCL also informed that the wrong VT fuse fail logic in P444 relay had been rectified on 19.01.2019.

10 Tripping of 400 kV Mamidapally - Dindi line-2

26-12-2018 at 01:42 hrs

Line tripped at Mamidipally end only without any indications. Line was kept charged from Mamidipally end.

GI-2

Dindi (TSTRANSCO) end:

As per FIR line is in open condition from Dindi end. Mamidapally (TSTRANSCO) end:

As per FIR/DR, line tripped at 01:42:06.498 hrs without any indications. In view of non-furnishing of proper reason for the subject tripping, TSTRANSCO was asked to keep

the line under observation, and instruct concerned station personnel to strictly adhere to standard O&M practices to avoid unwarranted trippings.

Annexure-II


11

Tripping of 400KV-Suryapet-Julurupadu line-2

26-12-2018 at 02:12 hrs

Line tripped on operation of Over Voltage stg-1 protection at Julurupadu & direct trip was received at Suryapet. Voltage recorded in Julurapadu end DR were as follows (R-247kV Y-248kV & B-245 kV). Same is observed to be less the the stg-1 setting and needs review

GI-2

26-12-2018 23:01 hrs

OVR-I gradings at 400kV Julurupadu:

*** F = 110%, 6 sec. Tripping on 26-12-2018 at 02:12 hrs: Suryapet (TSTRANSCO) end:

As per FIR/ EL line tripped at 02:07:17.767 hrs due to receipt of DT from the remote end.

DR/ TR not furnished.

Time-sync of PR’s with GPS needed to be ensured. Julurupadu (TSTRANSCO) end:

As per FIR/DR/EL line tripped at 02:12:54.386hrs due to OVR-I (Tov1 = 6sec) operation. [Vr=247.78V, Vy=248.289V, Vb=245.381V].

Tripping on 26-12-2018 23:01 hrs Suryapet (TSTRANSCO) end:

As per FIR/ EL line tripped at 22:55:56.789hrs due to receipt of DT from the remote end.

DR/ TR not furnished. Julurupadu (TSTRANSCO) end:

As per FIR/DR/EL line tripped at 23:01:33.472hrs due to OVR-I (Tov1 = 6sec) operation. [Vr=246.33V, Vy=246.902V, Vb=244.021V].

It was noted that on both the occasions there was no over voltage in the system; even then line had

tripped. When enquired about the reasons for the same, TSTRANSASCO informed that the Over Voltage settings at Julurupadu end were of old settings and not been revised. The Over Voltage settings are revised on 24-12-2018.

TSTRANSCO also informed that Drop-Off to Pick-up ratio of D60 was corrected to 0.978 on 04.01.2019.

When enquired about the reasons for not furnishing DR at Suryapet end, TSTRANSCO informed that at Suryapet end, DR was not triggered since the D60 relay had not been not configured to trigger DR at the time of tripping event. TSTRANSCO assured that the issue would be attended within two weeks.

12 Tripping of 400 kV Singareni - Sundila line-2

27-12-2018 17:22 hrs

Line tripped on Over voltage. FIR, DR and EL of both ends not furnished to validate the tripping

GI-2

OVR-I gradings at 400kV Sundilla:

*** D = 110%, 8 sec.

Annexure-II


Singareni (SCCL) end:

As per DR/ EL, line tripped at 17:22:32.998 hrs due to receipt of DT from the remote end.

FIR/ TR not furnished. Sundilla (TSTRANSCO) end:

As per FIR, line tripped at 17:22 hrs due to OVR-I operation.

DR/ EL/ TR not furnished --- due to this, OVR-I operation could not be verified.

TSTRANSCO informed that at Sundilla end DR was not triggered since the relay was not configured to trigger the DR. After tripping, the relay had been configured for triggering DR in the first week of January, 2019. The station personnel were also instructed about downloading procedures of DR.

13 Tripping of 230 kV Sullurupeta —Gummidipoondi line

30-12-2018 11:36 hrs

Line tripped from Gumudipoondi end and was holding from Sulurupeta end.

GI-1

SLD:

Annexure-II


Sullurpet (APTRANSCO) end:

As per FIR, line was kept holding from Sulurpet end. Gummidipoondi (TANTRANSCO) end:

As per FIR/ TR, line tripped at 11:35 hrs due to PT Supply failure.

DR and EL not submitted. TANTRANSCO:

To avail LC on 230 kV Northern side bus of Gummidipoondi SS, transferring of loads to southern bus was carried out without changing over of PT supply to relay panels. After changing over of all bays from northern bus the PT supply was not available to the relays.

Main-2 ( RAZOA ) Relay had issued Trip to Sullurpet feeder due to PT supply failure.

TANTRANSCO also informed that Main-2 (RAZOA) relay would be replaced by numerical relay soon. It was noted that there was no line CVT for 230 kV Sulurpet- Gummidipoondi line at

Gummidipoondi end Since the subject tripping was basically due to manual error, TANTRANSCO was asked to ensure that

their station personnel strictly adhere to/ follow standard operating procedures. Further in view of lot of generation being pooled to Gummidipoondi SS, TANTRANSCO was also

asked to expedite providing of line CVT’s, multi-bus_multi-zone operation [numerical BBP relay (SEL-421) had already been commissioned] at the station.

14

Tripping of 400 kV Anaikadavu-Rasipalayam lines - 1&2

31-12-2018 at 15:09 hrs

Due to DC earth fault, Direct Trip got extended from Rasipalayam end protection coupler to Anaikadavu end.

GI-2

Tripping of 400 kV Anaikadavu - Rasipalayam lines - 1 &2 : Rasipalayam (TANTRANSCO) end:

As per FIR, line was kept holding from Rasipalayam end.

It was stated in FIR that Direct Trip was extended from protection coupler due to DC leakage. Annaikadavu (TANTRANSCO) end:

As per FIR/DR/EL/TR, line tripped at 15:09:08.961 hrs due to receipt of DT from the remote end. It was noted that around the time of tripping event, maintenance works were going on at

Rasipalayam end. During routine testing works, DT accidentally got extended to remote end due to DC earth fault.

To this, TANTRANSCO was asked to ensure that due caution is exercised while carrying out routine maintenance works, and no unwanted trippings take place by lapse or negligence.

Annexure-II


III. Details of Trippings due to Failure or Non-operation of Auto-Reclose:

Sl. No. Element Date & Time Reason

1 Tripping of 220 kV KTPS-Nunna line

07-12-2018 at 11:32 hrs

B-phase to earth fault. Auto-reclose not enabled for line

KTPS (TSGENCO) end:

As per FIR, line tripped in 3-ph at 11:32 hrs on B-E fault due to DPR, Z1 operation. (23.8km; 2.939kA)

DR/EL/TR not furnished. Nunna (APTRANSCO) end:

As per FIR line tripped in 3-ph at 11:32hrs on B-E fault due to DPR, Z1 operation. (109.1 km;)

As per DR/EL line tripped in 3-ph at 10:27:49.116 hrs on Z2, CAT operation due to B-E fault.

Time-sync of PR’s with GPS needed to be ensured. It was noted that TSGENCO representative had not come to the meeting to explain their

perspective. When enquired about the reasons for not enabling A/R at Nunna end, APTRANSCO informed that

the pneumatic breakers at Nunna end were very old, and do not support A/R feature. It was also informed that replacement of those old breakers was being taken up, and A/R would be provided after their replacement.

IV. Details of Trippings due to PLCC mal-operation:

Sl. No. Element Date & Time Reason

1 Tripping of 400 kV Maradam – Kalpaka line-1

11-12-2018 at 11:55 hrs

Line tripped on Direct Trip receipt at Kalpaka and was in service from Maradam end.

Maradam (APTRANSCO) end:

As per FIR, line was kept holding from Maradam end. However, DT (TX) counter increment was observed in FIR.

Kalpaka (TSTRANSCO) end:

As per FIR/EL, line tripped due to DT receipt from the remote end. DT (RX) counter increment was observed in FIR.

APTRANSCO informed that during checking of DC leakage by M/s Amara Raja Company Engineer, DT got extended to Kalpaka-1&2 Feeders and tripped at Kalpaka end on DT receipt.

2 Tripping of 400 kV Maradam – Kalpaka line-2

11-12-2018 at 12:00 hrs

Line tripped on Direct Trip receipt at Kalpaka and was in service from Maradam end.

Maradam (APTRANSCO) end:

As per FIR, line was kept holding from Maradam end. However, DT (TX) counter increment was observed in FIR.

Kalpaka (TSTRANSCO) end:

As per FIR/EL, line tripped due to DT receipt from the remote end. DT (RX) counter increment was observed in FIR.

APTRANSCO informed that during checking of DC leakage by M/s Amara Raja Company Engineer, DT got extended to Kalpaka-1&2 Feeders and tripped at Kalpaka end on DT receipt.

Annexure-II


3 Tripping of 400 kV Warangal - Bhoopalapalli line-2

15-12-2018 at 20:42 hrs

Line tripped at Bhoopalapalli end only and was holding from warangal s/s. FIR, DR and EL of Bhoopalapally were not furnished.

FNN was not followed by TSGENCO. Warangal end (PGCIL-SR1):

As per FIR, line was kept holding from Warangal end. [No DT (TX) counter increment was observed] Bhoopalapalli end (TSGENCO):

As per FIR/ DR/ TR, line tripped at 20:41:09.795 hrs due to OVR-I operation. [Vr=253.35V, Vy= 249.589V, Vb= 253.02V]

EL not furnished. The furnished EL was even t summary of DR.

The DR furnished was improper since time scale (x-axis) and voltage scale (y-axis) had not been configured properly.

It was noted that no TSGENCO representative had come to the meeting to explain their

perspective. It was suspected that OVR operation at Bhoopalapally might have taken place after tripping of the

line due to receipt of DT from Warangal end. As informed by PGCIL (SR-I), since the existing PLCC panels at Warangal end or 400 kV Warangal –

bhoopalapally lnie-2 were very old (CGL make), TSTRANSCO was requested to consider replacing them with new PLCC panels for ensuring integrity of PLCC protection channels.

Recommendations: For the line under consideration, the following shall be carried out by TSGENCO in coordination with

PGCIL (SR-I): (i) End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends. (ii) Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components shall be repaired/ replaced.

*****

Annexure-II


Single line diagram of 230/ 110 kV Siruseri SS of TANTRANSCO

Annexure-II

Meeting

No /

Index

Details of Event Date & Time Reason PCSC Recommendations Utility responsible for

Implementation

Status of Implementation of PCSC Recommendations Remarks Latest Status

(To be filled up by the Constituent)

47/I/2 Complete outage of

Krishnapatnam TPS

08-09-2015

at 18:20 hrs

Status of Pending Implementation of PCSC Recommendations as on 14.02.2019 (up to 81th Meeting)

KPTCL Mail dated 27-05-2015:

1. KPTCL has taken action to provide bus bar protection to 220kV buses. --- Pending

2. Over current relay Settings of ICTs to be reviewed by PGCIL.

--- Pending

3. --- Pending

KPTCL Mail dated 29-07-2015:

1. Initial Tendering stage. --- Pending

2. --- Pending

3. --- Pending

KPTCL Mail dated on 23-01-2016:

1. Detailed estimate prepared for taking up the work. CEE, Transmission Zone, Gulbarga will

take up necessary procurement and further execution. --- Pending

2. --- Pending with PGCIL (SR-I).

3. --- Pending

PGCIL (SR-I) Mail dated 14.07.2016:

2. Relay settings of all the stations in SRTS-1 were derived as per Ramakrishna Commettee

recomendations and implemented" --- Completed.

KPTCL Mail dated 16.12.2017:

1) & 3). DPR is approved. Tender is to be called by CEE,TZ Kalaburgi --- Pending

Review Meeting dated 19.12.2017:

1. KPTCL informed that Tenders for providing BBP would be called in Jan-Feb, 2018; Supply of

the same is targeted by September, 2018; Erection & Commissioning is targeted by January,

2019

--- Pending

3. PGCIL (SR-I) informed that time-synchronization of 220 kV side is in place. --- Completed.

KPTCL mail dated 19.12.2018:

1. DPR preapared for the work of providing Bus Bar Protection to 220kV buses at Guddadahally

is approved. Tender is to be invited by CEE,TZ .


1. Tender would be floated in January 2019. Works would be completed in 6 months after

awarding PO.

16-07-2014

APGENCO letter dated 18.03.2016:

1.SOE and SLD are attached. The DR of 405 CB is not generated during the incident. Now the

problem is identified and rectified.

--------- Completed

2.All the 3 lines i.e CHTR-2, MNBL-I & II tripped in zone

protection. The fault was in Blind zone i.e P2 side of CT, where it was covered under Bus fault

by the time fault moved on to P1 side when the fault comes under STUB/TEED zone after

330msec all the feeders expect CHTR-1 tripped in Zone-II and total fault persisted for 500msec

before the 405 TIE CB opens and clear the fault. As a remedial the STUB protection operation

also checked and found OK.------- Completed

3.The Time Sync was missed on the day and found there was problem with LAN Timer same

was rectified. Now found OK.

-----------Completed

4.Now the DR Time scale changed to 1 sec for Pre fault and 3 sec for Post fault and STATE of

events are corrected wherever found wrong/or misguiding during analysis.---------Completed.

PGCIL-SR1 RVMD 27-04-2016:

5. Procurement of differential protection for 400kV NPS-NLR D/C and 400kV RCR-RTPS-D/C is

under tendering.


5. The proposal for procurement of Line differential Protections for 400kV Raichur - RTPS-1 & 2

and 400kV Nellore - NPS - 1 & 2 lines has been approved and tender is under technical

evaluation


PGCIL: On 23.11.2017 LDP relays commissioned in place of Main-1 distance relay in 400kV NPS-

Nellore line-2 & In line-1 installation of LDP relay is planned in Dec-2017/Jan-2018.


5. PGCIL (SR-I) informed that LDP commissioning on both lines would be completed by

February, 2018. In this regard, PCSC made it clear that the recommendation pertains to

providing LDP as both Main-I & Main-II on both the lines, and asked PGCIL (SR-I) to ensure &

comply with the same.

34/I/6 400/220 kV ICT-1 & 2 at

Munirabad

As reported directional over current relay of ICT’s operated

due to snapping of line jumper in 220kV Lingapur line.

1. Bus bar protection shall be provided by asset owner ( i.e

KPTCL).

2. Settings for main distance protection & Overcurrent

protection shall be examined and reviewed.

3. Time synchronization of the Substation shall be ensured.

KPTCL/

PGCIL (SR-I)

Pending

(with KPTCL)

Multi-Utilities

As per FIR submitted, CT damage observed in Chitoor-Main

bay (404). Main breakers connected to bus-1 (401, 404, 407,

410) got tripped on operation of bus bar protection. Unit-1

tripped on operation of MFT. Unit-2 was not in service

1. APGENCO to furnish to PCSC forum (i) A3-size Single Line

Diagram of SDSTPS, and (ii) the sequence of events with time

stamp showing the protection that opened Tie-CB (405) at

SDSTPS.

2. APGENCO to review STUB/TEED protection in all dias at

SDSTPS and ensure that they are configured for

instantaneous operation.

3. APGENCO to properly configure the STATE of the tripping

events so that they get recorded appropriately like TRIP/

OPERATED in their corresponding Event Loggers.

4. APGENCO to ensure time sync of all DR’s and EL’s at

SDSTPS.

5. PGCIL (SR-I) to provide line differential protection for 400

kV NPS –Nellore-PG lines 1 & 2.

APGENCO/

PGCIL (SR-I)

Pending

[with

PGCIL (SR-I)]

Annexure-III

Page 1 of 34

PGCIL (SR-I) mail dated 20.06.2018:

PGCI(SR1) procuring LDP relays for retrofitting of Main-1&2 distance relays. Tenders are invited

from bidders & tender floated. Technical bid opening in this week.


PO placed on M/s GE & TD India Ltd on 24.09.2018. Supply of relays is schdule for for January,

2019 and commissioning is targed to be completed by March, 2019.

PGCIL (SR-I) mail received on 27-04-2016:

1. The firmware of REL670 is being upgraded. ------- Completed.

2. The recording of events in msec interval is being taken up with OEM. Henceforth, for analysis

purpose, we will provide larm list which has msec time stamp. -------- Completed.

3. End to end testing of PLCC code transmision and tuning of channels carried out. -------

Completed.


under tendering. The legends modified in Event/alarm list. Provision of diff. relay for all short

lines emanating from NPS is being taken up with our corporate.

----- Pending.

PGCIL(SR-I) RVMD 14-07-2016:



evaluation --- Pending


4. LDP relays procurement is under process. Procurement will be completed by Feb-2018. TPCIL

has to give written confirmation for LDP relay procurement. For want of written confirmation

from TPCIL, PGCIL approving authority has withheld the LDP proposal.


4. PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete

procurement of LDP relays. To this, PCSC forum asked TPCIL to submit written confirmation to

PGCIL (SR-I) by 29.12.2017. PGCIL (SR-I) assured that with receipt of above confirmation from

TPCIL by Dec, 2017, they would be able to complete the work by FEbruary, 2018.

APTRANSCO informed that they would be able to implement LDP from their & APGENCO side

by April, 2018.

In this regard, PCSC forum made it clear that the recommendation is about providing LDP as

both Main-I & Main-II relays on all stated lines in Nellore Complex, ans asked all stakeholders to

ensure & comply with the same.





PO placed on M/s GE & TD India Ltd on 24.09.2018. Supply of relays will be completed by

Jan'2019 and commissioning by Mar'19

Complete outage of TPCIL power

station

PendingRunning units at Thermal Powertech power Station tripped

due to tripping of 400kV Nellore pooling station (NPS)-TPCIL

line and 400kV Nellore pooling station (NPS)-NCC line

47/I/2 Complete outage of

Krishnapatnam TPS

08-09-2015

at 18:20 hrs

APGENCO letter dated 18.03.2016:

1.SOE and SLD are attached. The DR of 405 CB is not generated during the incident. Now the

problem is identified and rectified.

--------- Completed

2.All the 3 lines i.e CHTR-2, MNBL-I & II tripped in zone

protection. The fault was in Blind zone i.e P2 side of CT, where it was covered under Bus fault

by the time fault moved on to P1 side when the fault comes under STUB/TEED zone after

330msec all the feeders expect CHTR-1 tripped in Zone-II and total fault persisted for 500msec

before the 405 TIE CB opens and clear the fault. As a remedial the STUB protection operation

also checked and found OK.------- Completed

3.The Time Sync was missed on the day and found there was problem with LAN Timer same

was rectified. Now found OK.

-----------Completed

4.Now the DR Time scale changed to 1 sec for Pre fault and 3 sec for Post fault and STATE of

events are corrected wherever found wrong/or misguiding during analysis.---------Completed.



under tendering.




evaluation


PGCIL: On 23.11.2017 LDP relays commissioned in place of Main-1 distance relay in 400kV NPS-

Nellore line-2 & In line-1 installation of LDP relay is planned in Dec-2017/Jan-2018.


5. PGCIL (SR-I) informed that LDP commissioning on both lines would be completed by

February, 2018. In this regard, PCSC made it clear that the recommendation pertains to

providing LDP as both Main-I & Main-II on both the lines, and asked PGCIL (SR-I) to ensure &

comply with the same.

PGCIL (SR-I),

MEPL, SEL, TPCIL, NCC

50/I/2 1.PGCIL (SR-I) to furnish Action Taken Report on the findings

of OEM on relay mal-operation at NPS end on 400 kV NPS –

NCC line to PCSC forum.

2. PGCIL (SR-I) to appropriately configure Station Event

Logger at NPS to record events at msec interval.

3. PGCIL (SR-I) to carry out PLCC end-to-end testing in

coordination with TPCIL for 400 kV NPS –TPCIL line.

4.PGCIL (SR-I), MEPL, SEL, TPCIL & NCC to take steps to

provide line differential protection at their respective ends

on all 400 kV lines (except Gooty line) emanating from

Nellore Pooling Station, and furnish an action plan to

implement the same.

30-12-2015 at

06:02hrs

As per FIR submitted, CT damage observed in Chitoor-Main

bay (404). Main breakers connected to bus-1 (401, 404, 407,

410) got tripped on operation of bus bar protection. Unit-1

tripped on operation of MFT. Unit-2 was not in service

1. APGENCO to furnish to PCSC forum (i) A3-size Single Line

Diagram of SDSTPS, and (ii) the sequence of events with time

stamp showing the protection that opened Tie-CB (405) at

SDSTPS.

2. APGENCO to review STUB/TEED protection in all dias at

SDSTPS and ensure that they are configured for

instantaneous operation.

3. APGENCO to properly configure the STATE of the tripping

events so that they get recorded appropriately like TRIP/

OPERATED in their corresponding Event Loggers.

4. APGENCO to ensure time sync of all DR’s and EL’s at

SDSTPS.

5. PGCIL (SR-I) to provide line differential protection for 400

kV NPS –Nellore-PG lines 1 & 2.

APGENCO/

PGCIL (SR-I)

Pending

[with

PGCIL (SR-I)]

Annexure-III

Page 2 of 34

APTRANSCO mail dated on 31-08-2016:

To avoid the unwanted malopeartions due to the external LBB trip initiation from PGCIL, Vide

letter Dt: 04-08-2016, APTRANSCO has requsted the PGCIL to arrange the Master trip relay and

breaker contacts of ICT-1 &2 LV side to enable the internal LBB feature in the Busbar protection

scheme at 220kV Gooty Switching station. Waiting for the PGCIL response.


To avoid the unwanted maloperations due to the external LBB trip initiation from PGCIL, vide

letter Dt: 04-08-2016, ARTRANSCO has requested the PGCIL to arrange the Master trip relay

and breaker contacts of ICT-1&2 LV side to enable the internal LBB feature in the Busbar

protection scheme at 220kV Gooty Switching station. Waiting for the PGCIL response.


Waiting for the PGCIL response.

APTRANSCO mail dated 04.03.2017 & 24.05.2017.

SRPC is requested to coordinate with PGCIL in takind necessary action.

APTRANSCO mail dated 20.09.2017 & 22.11.2017

PGCIL may be requested to take necessary actionAPTRANSCO maild ated 15.12.2017:

1. Cable healthiness checked and found ok. But it is proposed to replace the cable with

armored cable. --Completed

2. After replacing the cable contactors will be removed so as to avoid unwarrented delays in

transmitting trigging signal to the central unit . ---Pending


APTRANSCO informed that replacement of the existing cable with armoured cable and

subsequent removal of cable contactors would be completed by 31.12.2017. In this regard,

PGCIL (SR-I) also assured that they would render all required help from their side to complete

the stated works in time.

APTRANSCO Mail Dated 30.01.2018:

New armoured cable is laid from 220 kv Gooty (AP) to 400/220 kv Gooty (PGCIL) for replacing

the existing cable connected to ICT-2.PGCIL is requested to provide spare contacts from trip

relays of 315 mva LV-1 and LV-2 for providing internal CB failure in busbar protection scheme.

APTRANSCO Mail Dated 24.04.2018 & 24.05.2018:

As requested by PGCIL the busbar drawings Were submitted for providing spare contacts from

trip relays of 315 mva LV-1 and LV-2 for providing LBB in busbar protection scheme.


220kV CB LBB protection (Stand alone protection) available at PGCIL end is to protect ICT in

case of non tripping of CB. It is opined that stand alone protection is better than new LBB logic

proposed by APTRANSCO in Busbar schme. The reason for mal-operation of 220kV Bus on

24.06.2016 is mainly due to cable issue. The problem shall be solved once we replace, this

suspected cable betweem POWERGRID & APTRANSCO.


PGCIL was requested to arrange LC & coordinate for completeing the work.


220kV CB LBB protection (Stand alone protection) available at PGCIL end is to protect ICT in

case of non tripping of CB. It is opined that stand alone protection is better than new LBB logic

proposed by APTRANSCO in Busbar schme. The reason for mal-operation of 220kV Bus on

24.06.2016 is mainly due to cable issue. The problem shall be solved once APTRANSCO replaces

suspected cable, this suspected cable betweem POWERGRID & APTRANSCO.

In this regard a letter dtd 22.09.2018 hasbeen sent to EE, MRT & T/F, Ananthapur, AP TRANSCO

that the required relay contact will not provided by POWERGRID.

Review Meeting held on 20.12.2018:

Cable laying work was completed by PGCIL (SR-I). It was agreed that the work would be

completed by PGCIL (SR-I), in cordination with APTRANSCO, within one month.

APTRANSCO MAIL DATED 22.01.2019:

Pending [ with PGCIL (SR-I) ]

Tripping at 220 kV Gooty

Substation of APTRANSCO

56/II/13 24-06-2016 at 16:04

hrs

Pending [ with PGCIL

(SR-I) ]

APTRANSCO/

PGCIL (SR-I)

1.APTRANSCO to check the healthiness of the connecting

cable between Gooty (PGCIL) and Gooty (APTRANSCO), and

replace it, if required.

2.APTRANSCO to ensure that the distributed architecture

employed in implementing busbar protection at their Gooty

220 kV SS does not introduce any unwarranted delays in

transmitting the triggering signals to the Central Unit.

LBB protection got operated for 400/220kV ICT-2 breaker

which had resulted in tripping of 220kV Bus-2 at 220kV Gooty

Substation

Annexure-III

Page 3 of 34


ABB make LDP relays inspection is completed. SNEIDER make LDP relays inspection yet to be

completed. Delivery of relays expected in the 1st weak of May-2018.


SNEIDER make LDP relays inspection yet to be completed.Delivery of relays expected in the

month of june 2018.





ABB make LDP relays are delivered. Schneider make LDP relays inspection to be offered by the

company.


schneider LDP relays inspection yet to be offered by the company.


ABB make LDP relays for Main-1 protection were delivered earlier and schneider make LDP

relays for Main-2 protection are delivered in this week.


ABB & SCHNEIDER Relays are drawn and available at site. To be commissioned in coordination

with the Alstom (Area) engineers who implemented SAS.


PGCIL(SR-1): PO placed on M/s GE & TD India Ltd on 24.09.2018. Supply of relays will be

completed by Jan'2019 and commissioning by Mar'19


The relays are yet to be commissioned.

18-07-2016

at 19:05 hrs

PGCIL (SR-I), TPCIL, MEPL, SEL, SGPL, APTRANSCO, APGENCO

and SDSTPS to implement line differential protection on all

400 kV transmission lines (of length less than 50 km)

emanating from Nellore PS, Nellore (PG) SS, and Nellore (AP)

SS. [It may be noted here that the cut-off length of 50 km has

been specified with a view to exclude only long transmission

lines].

APGENCO/

PGCIL(SR-I)/

TPCIL/MEPL/SEL/

SGPL/ APTRANSCO

57/II/9 Tripping of 400 kV Nellore (PG) -

NPS line-1, 400 kV

Krishnapatnam-Nellore (AP)

lines -1&2 and 400kV NPS -

MEPL line

PendingAPTRANSCO mail dated on 20-12-2016:

Issue was addressed to the concerned for necessary action.


Meeting was conducted and the relays procurement for all the loctions is under progress.

APTRANSCO mail dated on 20-10-2017 & 22.11.2017:

Relays procurement for all the locations is under progress.

APTRANSCO Mail dated 15.12.2017:

Technical bids opened. PQ evaluation under progress . Price bids expected to open in next

week.


LDP relays procurement is under process. Procurement will be completed by Feb-2018. TPCIL

has to give written confirmation for LDP relay procurement. For want of written confirmation

from TPCIL, PGCIL approving authority has withheld the LDP proposal.


PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete



TPCIL by Dec, 2017, they would be able to complete the work by FEbruary, 2018.


by April, 2018.




APTRANSCO MAIL DATED 30.01.2018

Technical & financial bids are opened. Tenders will be awarded shortly.

Triggering incident was snapping of Y phase conductor in

400kV Nellore (PG) - NPS line-1. Distance relay at

Krishnapatnam end over-reached in Zone-1, and resulted in

tripping of 400kV Krishnapatnam – Nellore (AP) lines - 1&2

from Krishnapatnam end. Distance relay at MEPL over-

reached and resulted in tripping of MEPL-NPS line from MEPL

end.

Annexure-III

Page 4 of 34

64/I/1 Complete outage of North

Chennai TPS STG-2

24-04-2017

at 21:02hrs

Tripping of evacuating lines due to fault led to tripping of

Units


Chennai TPS STG-2

25-04-2017

at 18:27hrs


Unit


Chennai TPS STG-2

26-03-2017

at 21:09 hrs


running Unit at NCTPS Stg-2

TANTRANSCO MAIL DATED 22.05.2018:

Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer

insulators in a phased manner. Timeline: Sep-2018. Detailed plan of action will be submitted.






insulators in a phased manner. Timeline: Sep-2018.



insulators in a phased manner. Timeline: Dec-2018.


1.Replacement of porcelain insulators with Polymer insulator for 4 Km radius from NCTPS.2 in

400kV SVCM & Alamathy feeders were completed.

2. Further, Procurement under progress for replacement of 230kV and 110 kV porcelain

insulators with Polymer insulator in coastel area.Time line . June 2019.


Time Line requested upto June 2019

Status received vide TANTRANSCO mail dated 15-06-2017 & 04.08.2017 & 18.09.2017 & 12-12-

2017:

1. All the Porcelain insulators of 400kV NCTPS-II - Vallur feeders-1&2 were replaced with

Polymer insulators by 20.05.2017. -----Completed

2. Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer

insulators in a phased manner.

--- Pending

PGCIL (SR-II) Mail dated 11-12-2017:

Pertaining to POWERGRID all the porceleing insulators in the polluted streches has been

completed. - Completed.


TANTRANSCO informed that a total of 597 insulators ahd alreeady been replaced, and the total

replacement would take another 9-month period.

In this regard, TANTRANSCO was asked to furnish detailed plan of action regarding replacement

of insulators on all 400 kV lines owned by them in Chennai area.






insulators in a phased manner. Timeline: Sep-2018.

TANTRANSCO and PGCIL (SR-II) to take steps to complete

insulator replacement works on the 400 kV lines owned by

them in Chennai area within 3 months.

TANTRANSCO/

PGCIL(SR-II)

Pending

[with TANTRANSCO]

Annexure-III

Page 5 of 34

NTPC mail dated 07.12.2017:

1. High set DEFR on 220 KV lines is disabled ----Completed

2. ---- Pending


TSTRANSCO informed that the works are under progress, and are targeted to be completed in 3

months time.

TSTRANSCO MAIL DATED 20.01.2018:

Line Differential Protection will be provided within 3 months i.e., by end of March, 2018.


Line Differential Protection relays are under procurement and will be provided by end of May,

2018.


Line Differential relays will be supplied to site by manufacturer by end of May, 2018 and

erection will be completed by end of June, 2018.


Inspection of the relays is completed and the relays are received at stores. Relays are to be

drawn and commissioned. Work is expected to be completed by end of December 2018.


Relays will be commissioned by end of February, 2019.

66/ II/ 10 Tripping of 400/ 220 kV ICT’s – 3

& 4 at Ramagundam STPS

NTPC-Ramagundam/

TSTRANSCO

PendingTriggering incident was failure of 220 kV

B-phase LA in ICT-3 LV extension feeder (220KV line-2) at

Malayalapalli substation

1. NTPC to disable high-set of DEFR on the 220 kV lines

emanating from their Ramagundam STPS.

2. NTPC/ TSTRANSCO to provide Line Differential Protection

(with or without pilot) on 220 kV Ramagundam –

Malayalapalli lines – 1 & 2 & 3.

11-06-2017

at 19:46hrs

Annexure-III

Page 6 of 34

69/I/2 Complete outage of 400kV TPCIL

station

30-10-2017 at 21:37

hrs

400kV TPCIL - Nellore line-1 got tripped at TPCIL end during

failure of LA of Station Transformer-2 at TPCIL. Running Units

at TPCIL got tripped due to loss of evacuating line. 400kV

TPCIL - Nellore PS line-2 was under emergency shutdown

1. TPCIL to configure DEF protection such that it remains in

blocked condition as long as Distance Protection is active,

and becomes active only when distance protection does not

pickup.

2.PGCIL (SR-I) to ensure healthiness of Carrier

communication, and the set PUP mode of carrier aided

scheme operates reliably on TPCIL lines 1 & 2.

TPCIL/

PGCIL (SR-I)


PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete



TPCIL by Dec, 2017, they would be able to complete the work by February, 2018.


by April, 2018.





2. PGCI(SR1) procuring LDP relays for retrofitting of Main-1&2 distance relays. Tenders are

invited from bidders & tender floated. Technical bid opening in this week.


2. PO placed on M/s GE & TD India Ltd on 24.09.2018. Supply of relays will be completed by

Jan'2019 and commissioning by Mar'19.

Review Meeting on 20.12.2018:

1. It was noted that TPCIL representatives have not attended the meting. TPCIL wasked to

furnish implementation status of the given recommendation at the earliest.

Pending

APTRANSCO maild ated 30.01.2018:

1. Pending...

2.A/R scheme on 400kV Kurnool (PGCIL) feeder-2 will be checked after getting LC.

APTRANSCO maild ated 24.04.2018 & 24.05.2018 & 26.06.2018:

1. Pending...

2. B Ph auxilary trip relay is found defective. The same is to be replaced by M/S PGCIL. Ii) PD

relay event is configured in the EL as per the recommendation.


1. ---Pending

2. PGCIl(SR-1): B-Ph auxiliary relay problem rectified at Narnoor end by replacing relay contact. -

--Completed


Lines and Bays pertain to PGCILAPTRANSCO Mail Dated 18.12.2018:

1) Bays and lines pertains to PGCIL .

2) ---Completed.


1) PO placed on M/s GE & TD India Ltd on 24.09.2018. Supply of relays will be completed by

Jan'2019.


Pending [with PGCIL (SR-I)]

APTRANSCO maild ated 15.12.2017:

APTRANSCO would extend support and requirements if any ,for the rectification proposed by

KPTCL.


It was noted that the original Gooty - Lingapur line got LILOed at BTPS, Alipura, and

Ragulapadu. It was also noted that Phase Discrepancy is being observed in Ragulapadu - Alipira

section only. When enquired about the same, KPTCL informed that they would examine the

issue in detail, and would inform the action lan proposed by next PCSC-71 meeting. On this,

APTRANSCO was also asked to render all help required from their side to KPTCL.

APTRANSCO maild dated 30.01.2018:

APTransco world extend required support .

APTRANSCO maild dated 24.04.2018 & 24.05.2018 & 26.06.2018:

AP Transco would extend required support for attending, phase discrepancy issue in ragulapadu-

Alipura line by KPTCL.


To be attended by KPTCL as discussed in 75th PCSC meeting.


Phase mis match issue is to be sorted out jointly by KPTCL/ APTRANSCO/ KPCL.

69/III/7 Tripping of 220 kV Ragulapadu –

Alipura line

12-10-2017 at 01:30

hrs

Line tripped on B-Ph to earth fault. A/R was successful at

Regulapadu and breakers at Alipura end got tripped.

KPTCL and APTRANSCO to sort out issues relating to

incongruence in denoting R, Y, B phases of the electric supply

on their respective sides.

APTRANSCO/ KPTCL Pending

[with KPTCL ]

APTRANSCO/

PGCIL (SR-I)

69/III/3 Tripping of 400 kV Kurnool(PG) –

Kurnool(AP) line-2

02-10-2017 at 02:03

hrs

1) PGCIL (SR-I) and APTRANSCO to provide for Line

Differential Protection as both the Main protections on 400

kV Kurnool (AP) – Kurnool (PG) lines 1 & 2 lines.

2) APTRANSCO to furnish an action taken report w.r.t.

resolving A/R non-operation at Kurnool-AP end for the

subject trippings and configure EL for capturing PDR

operation at their 400 kV Kurnool-AP SS.

Line tripped on B-ph to ground fault. A/R was unsuccessful at

both Kurnool (AP) and Kurnool (PG) ends.

Pending [with PGCIL

(SR-I)]

Annexure-III

Page 7 of 34


PCSC forum decided that concrete action in this respect to be initiated in 2 months by KPTCL

alongwith APTRANSCO.


Pending [with KPTCL ]

76/II/9 Tripping of 230 kV Thiruvalam -

Chittoor line

13-06-2018 at

18:55hrs

Y-phase to earth fault occurred in line. At 230 kV Tiruvalam

end, breaker was under lockout leading to operation of LBB

protection.

1) TANTRANSCO to provide double-bus operation at their

230 kV Thiruvalam SS.

2) APTRANSCO to replace the existing static relays with

suitable numerical relays for various line protections at their

220 kV Chittoor SS.

TANTRANSCO/ APTRANSCO 1) TANTRANSCO Mail dated 29.08.2018 & 11.09.2018:

Material supplied and work to be taken up ---Pending

2) APTRANSCO Mail dated 24.09.2018:

The static relays were replaced with Numerical relay on all 220 kV feeders at 220 kV SS chittoor.-

--Completed

TANTRANSCO Mail dated 11.12.2018:

Due to space constraint, the equipments could not be erected.


In view of Tiruvalam being inter-state sustation, TANTRANSCO was asked to prvodie double-bus

operation at their 230 kV Tiruvalam SS.


Pending [with TANTRANSCO]


Feasibility for providing hybrid breaker / shifting of bays will be studied & action will be taken.

Time upto Sep 2019

Pending [with

TANTRANSCO]

78/I/2 Complete outage of 220 kV

Nagjheri PH and 220/110 kV

Ambewadi Substation.

17-09-2018 at

14:37hrs

220kV lines connected to Nagjheri PH got tripped due to

successive transient faults. Running Units #3 and #4 at

Nagjheri got tripped on over frequency protection operation

due to loss of evacuating lines resulting in complete outage

of 220 kV Nagjheri. 220 kV Nagjheri being the only source to

220kV Ambewadi station, since 220kV Ambewadi Narendra

line 1&2 were under shutdown during antecedent condition,

tripping of Units at 220 kV Nagjheri resulted in the loss of

supply to 220 kV Ambewadi SS.

1. SLDC/KPTCL to be pro-active in issuing necessary

directions that help in expeditious restoration of the tripped

lines based on the prevailing conditions and grid security.

2.KPCL to implement A/R enabled on all 220 kV lines

emanating from their 220 kV Nagjheri PH, with the help of

KPTCL, by December, 2018. In the event of non-amenability

of the existing PZ1000 relays in providing A/R feature, KPCL

shall take steps to retrofit them with suitable relays that

support A/R.

3. KPTCL to restore PLCC carrier communication on 220 kV

Nagjheri – Bidnal line at the earliest

KPCL/ KPTCL KPTCL mail dated 19.12.2018:

3). Nagzari-Bidnal PLCC link is healthy --- Completed.

1.--- Pending

2. --- Pending


1. & 3. Completed

2. Pending

KPCL mail dated 24-12-2018:

1) --- Completed

2) Proposal will be taken up for replacement of existing PZ1000 relays with new version

Numerical Line protection relays having IEC61850 shortly, after availing necessary admnistrative

approval...Pending

3) Completed

KPCL mail dated 23.01.2019:

1. Completed

2. Letter addressed to site to take up the proposal for replacement of PZ1000 line distance

relays.

3. Completed

Pending

78/II/3 Multiple trippings at 400 kV

Julurupadu

01-08-2018

at 19:33 hrs

400kV Julurupadu-KTPSVII line-1 tripped at at Julurupadu end

on SOTF due to 3-phase to ground fault while charging the

line. 400kV Julurupadu-KTPSVII line-2 tripped at KTPSVII end

due to Over Current protection and 400kV Julurupadu-

Suryapet-2 feeder tripped at Suryapet end on STUB(I>4)

indications.

1) TSGENCO to ensure that the mandate operations

procedures are duly followed by their station personnel at

KTPS end whenever any LC is taken or returned.

2) TSGENCO to ensure the following on all 400 kV lines

emanating from their KTPS-VII station:

• O/C protection is kept disabled.

• High-set operation of line’s DEF protection is kept disabled;

IDMT settings of DEF protection are suitably kept.

3)TSTRANSCO to resolve issues w.r.t. Stub protection

operation at Suryapet end relays for the 400 kV Suryapet -

Julurupadu line-2, and intimate the corrective action taken to

PCSC forum.

TSGENCO/ TSTRANSCO TSTRANSCO mail dated 14-11-2018:

1) Pending.

2) Pending.

3) The stub operation in P444 relay at Suryapet end is due to logic problem and is rectified on

28-10-2018.---Completed.

TSTRANSCO mail dated 27-11-2018:

1) TSGENCO ( AT KTPS - VII stage ) Strictly adhering the operations procedures and following

the standard procedures while taking and returning LC . -

Completed

2) TSGENCO ( at KTPS - VII Stage ) is adopted the settings from TSTRANSCO for the 400 kv

feederes. The settings will be modified accordingly in coordination with TSTRANSCO. --

Pending

3) Completed


2. TSGENCO informed that the modification of settings will be completed in 1 month.

-----Pending

Pending

69/III/7 Tripping of 220 kV Ragulapadu –

Alipura line

12-10-2017 at 01:30

hrs

Line tripped on B-Ph to earth fault. A/R was successful at

Regulapadu and breakers at Alipura end got tripped.

KPTCL and APTRANSCO to sort out issues relating to

incongruence in denoting R, Y, B phases of the electric supply

on their respective sides.

APTRANSCO/ KPTCL Pending

[with KPTCL ]

Annexure-III

Page 8 of 34

78/II/16 Multiple trippings at 220kV

Nagjheri PH

31-08-2018

at 11:49 hrs

Triggering incident was B-E fault in 220 kV Nagjheri -

Ambewadi line-1. As per the information received, after

tripping of 220 kV Naghjeri - Ambewadi line-1, 220 kV

Naghjeri Ambewadi line#2 got overloaded. This resulted in

the tripping of Nagjheri Generating Units #3 and 6 on SPS

operation. At the same time, Unit #2 got tripped on REF

operation.

1)KPTCL to examine the reasons for tripping of more than

one Unit (Units – 3 & 6) on SPS operation at Nagjheri PH

during subject trippings, and furnish a report on the same

along with remedial action taken to PCSC forum.

2)KPCL to employ a suitable time delay of 50 – 60 msec in

operation of REF protection for the GT of Unit-2 at their

Nagjheri PH.

KPTCL/ KPCL Review Meeting on 20.12.2018:

1. KPTCL I formed that SPS scheme finalisation shall be completed in one month time ---

Pending

KPCL mail dated 24-12-2018:

2) Time delay of operation is not changed. However, the external NCT is used for REF

protection against earlier internal NCT for REF, to avoid tripping due to malopration ---

Completed.


1) It shall be reviewd and Implemented by KPCL in coordination with KPTCL.

2)....Completed.

Pending

79/I/2 Complete outage of 230/ 110 kV

Gummidipoondi Substation

05-10-2018 at 00:42

hrs

Triggering incident was B-phase fault at 230kV

Gummidipoondi Substation due to which 230kV Bus-1 Bus-

bar protection operated. 230kV Gummidipoondi Station was

under single bus operation, hence operation of Bus-bar

protection resulted in tripping of all connected elements.

1) TANTRANSCO to take steps to implement multi-bus, multi-

zone operation (Double-bus operation) at their 230 kV

Gummidipooindi SS by December, 22018.

2) TANTRANSCO to check if the Gummidipoondi substation is

adequately protected from lightning-strokes by providing

requisite no. of lightning masts and/ or earth-wire caging.

3) APTRANSCO was asked to verify & correct the settings

employed for distance protection at Sullurpeta and configure

DR’s & EL’s of all Protection Relays at their Supllurpet SS

properly for recording only the mandated protections &

digital signals.

TANTRANSCO/ APTRANSCO TANTRANSCO Mail dated 11.12.2018:

1. TANTRANSCO: Estimate sanctioned for replacement of defective isolator status feedback.

Work under progress. ......Pending

2.Earth value of 110kV earthmat has been improved & 230kV side earthmat work under

progress. Lightning mask earthing renovation under execution............Pending

3.......Pending


Relays settings reviewed and need to be revised due to change of line length DR & EL's of Main-

1 (P444) relay configured properly. Main-2 (D60) relay to be configured.


1 & 2). TANTRANSCO informed that Work will be completed by March 2019.

3. APTRANSCO informed that work will be completed by February 2019.


Collecting the details of adjacent feeders connected to Gummadipudi for computing revised

relay settings.


Isolator status will be ensured by March 2019

Pending

81/IV/3 Tripping of 400 kV Warangal -

Bhoopalapalli line-2

15-12-2018 at 20:42

hrs

Line tripped at Bhoopalapalli end only and was holding from

warangal s/s. FIR, DR and EL of Bhoopalapally were not

furnished.

For the line under consideration, the following shall be

carried out by TSGENCO in coordination with PGCIL (SR-I):

(i) End-to-end communication for DT/ permissive & other

signals may be ensured by testing at both the ends.

(ii) Healthiness of PLCC system components (hardware and

software) at both ends shall be checked and faulty

components shall be repaired/ replaced.

TSGENCO/ PGCIL (SR-I) Yet to be informed Pending

Andhra Pradesh

Annexure-III

Page 9 of 34

57/II/9 Tripping of 400 kV Nellore (PG) -

NPS line-1, 400 kV

Krishnapatnam-Nellore (AP)

lines -1&2 and 400kV NPS -

MEPL line

18-07-2016

at 19:05 hrs

Triggering incident was snapping of Y phase conductor in

400kV Nellore (PG) - NPS line-1. Distance relay at

Krishnapatnam end over-reached in Zone-1, and resulted in

tripping of 400kV Krishnapatnam – Nellore (AP) lines - 1&2

from Krishnapatnam end. Distance relay at MEPL over-

reached and resulted in tripping of MEPL-NPS line from MEPL

end.

APGENCO to furnish a report on the remedial action

implemented w.r.t. overreaching of Krishnapatnam end

distance relays during the tripping of 400 kV Nellore (PG) -

NPS line-1

APGENCO Review Meeting dated 19.12.2017:

It was noted that no APGENCO representative had come to attend the meeting.

APGENCO Mail dated 19.12.2017:

Procurement of relays is under progress


APGENCO representatives had not come to attend the meeting.

Pending

74/II/21 Tripping of 400 KV Kalikiri –

RYTPP line-2

29-04-2018 at 19:29

hrs

Line tripped on operation of over-voltage protection at

RYTPP and Direct Trip receipt at Kalikiri. The correct

operation of over-voltage tripping could not be validated as

FIR, DR and EL of RYTPP and DR and EL of Kalikiri were not

furnished.

1). APGENCO to furnish detailed report on the reasons for

the tripping of the line including remedial measures taken.

2). APGENCO to ensure that the OVR-settings implemented

at Rayalaseema TPP are as per the SRPC provided settings

issued vide letter dated 01.05.2018, and confirm the same.

APGENCO Status received vide mail dated 25.09.2018:

2). OVR settinss incorporated as per the Lr.No. CE/IPC&PS/SP/13/

400KV -OVR -SRPC/VOL.OI/ D.No,2001333/ 18: Dt: 04.05.18 --- Completed


1). It was noted that no APGENCO representative had come to attend the meeting --- Pending

Pending


Kalikiri and 400 kV RyTPP, Stage-

V station

16:08 hrs on

11-05-2018

Triggering incident was R-E fault in 400kV RyTPP- Kalikiri Ckt-

1. Auto reclose (A/ R) was successful at Kalikiri end but didn’t

operate at RyTPP end. This led to tripping of running unit at

RyTPP due to tripping of evacuating line and complete

outage of RYTPP. At the same time 400kV Chittoor-Kalikiri

lines - 1&2 got tripped from Chittoor end on operation of Z3

(mal-operation) resulting in loss of supply to Kalikiri station.

APGENCO to ensure that A/R functionality implemented on

400 kV RyTPP (Stage-V) – Kalikiri lines – 1 & 2 at RyTPP (Stage-

V) end is healthy and in kept service.

APGENCO Status received vide mail dated 25.09.2018:

RTPP,(9taqe-lU end,iis healthy and kept in service. Hence it is requested to drop all the ahove

points.


It was noted that no APGENCO representative had come to attend the meeting

--- Pending

Pending

79/III/8 Tripping of 400 kV RYTPP-Kalikiri

line-2

26-09-2018 at 21:13

hrs

Line tripped on B-N fault. Auto-reclose was successful at

Kalikiri and three phase trip at RYTPP due to A/R lock-out.

APGENCO to furnish a detailed report on tripping event

bringing out reasons for A/R non-operation at yTPP end on

400 kV RyTPP – Kalikiri line along with remedial action taken

to PCSC forum.

APGENCO Review Meeting dated 20.12.2018:

It was noted that no APGENCO representative had come to attend the meeting.

Pending


Vizag (Gazuwaka) switching

station

27-03-2018 at 16:14

hrs

Triggering incident was R-ph CT failure Bus-Coupler. This

resulted in tripping of all the connected elements due to

operation of bus bar protection.

1) APTRANSCO to furnish equipment failure report of the

current incident (CT blast) to PSE&TD Division of CEA with a

copy marked to SRPC.

2) APTRANSCO to take steps to provide one more thermo-

vision camera to Vizag division for use exclusively on 400 kV

& 220 & 132 kV transmission lines emanating from Kalpaka,

Gajuwaka, VSS, Pendurti and other adjoining substations of

APTRANSCO.

APTRANSCO APTRANSCO Mail Dated 26.06.2018 & 25.07.2018:

1. Vide Lr.No.CE/Tr/SE/Tr/DE/SS/ADE-4/F.No.1/D.No.138/18Dt:20.06.18. Equipment & failure

report communicated to CE(STED),CE/(IC),CEA.

---Complied.

2. Indent is being processed.---Pending.

APTRANSCO Mail dated 24.09.2018:

2. Tendering process has been initiated. ---Pending


2. Purchase order placed on 20.09.2018.


2. APTRANSCO informed that Timeline for completion of work is March 2019.


Test reports received. Dispatch instructions to be given.

Pending

80/II/18 Tripping of 400 kV Uravakonda -

Veltoor line-2

19-11-2018 at 12:00

Hrs

As per FIR, 400 kV Uravakonda - Veltoor Line-2 tripped on

operation of overvoltage Stage-1 at Uravakonda end and DT

received at veltoor end. From the DR furnished, voltages at

Uravakonda end are: Vr- 243kV, Vy-245kV and Vb-242kV.

From the DR operation of Overvoltage Stage-1 protection

could not be established. Over voltage grading of the line at

Uravakonda end is 109%, 6secs, tripping is not as per grading.

APTRANSCO to adopt recommended OVR, Stage-I and OVR,

Stage-II protections at their 400 kV Uravakonda SS, and to

ensure that OVR-I_START signal is configured for triggering

corresponding Event Logger (EL), and OVR-I_TRIP is

configured for triggering corresponding Event Logger (EL)

and Disturbance Recorder (DR).

APTRANSCO APTRANSCO MAIL DATED 22.01.2019:

Informed to M/s siemens to configure the OVR signals.

Pending

Annexure-III

Page 10 of 34

07-11-2017 at 23:02

hrs

09-11-2017 at 21:57

hrs

12-11-2017 at 20:54

hrs

17-11-2017 at 21:19

hrs

11-11-2017 at 22:02

hrs

12-11-2017 at 23:09

hrs

24-11-2017 at 18:46

hrs

11-12-2017 at 18:49

hrs

18-12-2017 at 19:10

hrs

74/II/2 Tripping of 400 kV Kurnool-

Srisailam line

01-04-2018 at 18:03

hrs

Line tripped on operation of Over Voltage Stg-1 protection at

Srisailam and Direct Trip was received at Kurnool.

Considerable difference between Phase voltages was

observed in Srisailam end DR. (Vr-257kV, Vy-246kV, Vb-

239kV)

1). TSGENCO was asked to double—check the faulty CVT’s

and replace them at the earliest.

2). TSGENCO was also asked to implement new OVR gradings

issued vide SRPC letter dated 01.05.2018.

TSGENCO TSGENCO mail dated 31.07.2018:

1. TSGENCO: Purchase order was placed on 08.03.2018 for procurement of CVT’s & after receipt

of new CVT’s faulty CVT’s will be replaced with new CVT’s. Replacement of faulty CVT's will be

completed by the end of September 2018.

--- Pending

2.TSGENCO: TSGENCO was implemented new OVR gradings issued by SRPC

--- Completed.


1. TSGENCO informed that CVT replacemen will be completed by January 2019

Pending

Tripping of 400kV Kurnool-

Srisailam line

TSGENCO to adopt stipulated OVR, Stage-I gradings for the

400 kV lines emanating from their 400 kV Srisailam LB RH,

and furnish an action taken report w.r.t. mitigating observed

voltage difference among R & Y & B phases.

PendingTripping of 400 kV Satenapalli-

Srisailam line-1

70/II/2

Tripping of 400 kV Narnoor –

Srisailam LB line

Line tripped due to operation of over voltage protection at

Srisailam LB end. Considerable phase difference was

observed between phases at Srisailam end

Pending

Pending

1. TSGENCO to take steps to replace the existing faulty CVT’s

at Srisalam end on 400 kV Srisailam – Narnoor line at the

earliest.

2. TSGENCO to adopt stipulated OVR, Stage-I gradings on all

400 kV transmission lines emanating from Srisaliam LB.


1.TSGENCO: Purchase order was placed on 08.03.2018 for procurement of CVT’s & after receipt



---Pending

2.TSGENCO: TSGENCO was adopted new OVR stage-1 gradings on all feeders issued by SRPC. ---

Complied


1. TSGENCO informed that CVT replacemen would be completed by January 2019

------- Pending


Srisailam and Direct Trip was received at Sattenapalli.

Considerable voltage difference was observed between R, Y

& B phases at Srisailam end.

71/II/7

70/II/3

Telangana

TSGENCO mail dated 31.07.2018:

TSGENCO: Purchase order was placed on 08.03.2018 for procurement of CVT’s & after receipt



TSGENCO: TSGENCO was adopted new OVR stage-1 gradings on all feeders issued by SRPC.


TSGENCO informed that CVT replacement would be completed by January 2019.

TSGENCO to adopt stipulated OVR, Stage-I gradings for the

400 kV lines emanating from their 400 kV Srisailam LB RH,

and furnish an action taken report w.r.t. mitigating observed

voltage difference among R & Y & B phases

Line tripped on operation of Over-Voltage protection at

Srisailam and Direct Trip was received at Kurnool.

Considerable voltage difference was observed between R, Y

& B phases.


TSGENCO: Purchase order was placed on 08.03.2018 for procurement of CVT’s & after receipt



TSGENCO: TSGENCO was adopted new OVR stage-1 gradings on all feeders issued by SRPC.


TSGENCO informed that CVT replacemen would be completed by January 2019

TSGENCO

Annexure-III

Page 11 of 34

74/II/8 Tripping of 400/220 kV ICT-2 at

Gajwel

11-04-2018 at 5:50

hrs

400/220 kV ICT-2 at Gajwel tripped on mal-operation of

Buchholtz relay.

1). TSTRANSCO was asked to keep the ICT and its mechanical

protections under observation for detecting any slippages.

2). TSTRANSCO was also asked to configure capturing of

mechanical protections of ICT’s in the respective relay’s/

station’s event logger.

TSTRANSCO TSTRANSCO mail dated 20.06.2018:

1. Mechanical protections of ICTs is under observation. --- Completed

2.New relays are available at site and will be commissioned by 2nd week of August-2018. The

mechanical protection of ICTs will be configured in the new relays ----Pending


2. New relays will be commissioned by end of November-2018 and the Over Voltage settings

will be implemented after commissioning in new relays ----Pending


2. New relays will be commissioned by end of January-2019 and the mechanical protections of

ICTs will be configured in the new relays ----Pending



Pending

PAR/

PCSC-58

TSGENCO/ TSTRANSCO The issue was discussed in PCSC-58 meeting held on 18.10.2016, when PCSC forum agreed to

de-link the implementation of the Item from the scope of Protection Audit Recommendations

(PAR), and pursue it as part of PCSC Recommendations.

TSGENCO mail dated 30-05-2017

Procurement of Differential Protection relays is under process and the work will be completed

by the end of November 2017.

TSGENCO mail dated 18-09-2017

Procurement of Line Differential Protection Relays is under process and the work will be

completed by the end of January 2018.


TSGENCO informed that they are in constant touch with TSTRANSCO in this regard, and hope to

implement LDP by February, 2018.

TSTRANSCO informed that procurement of LDP relays is under progress, and assured that LDP

would be implemented in 3-months time.

TSTRANSCO MAIL DATED ON 20-01-2018:

The matter is being coordinated with TSGENCO.

TSTRANSCO MAIL DATED ON 05-03-2018:

As a part of implementation of line differential relays for short distance (Jurala PH to Jurala SS)

feeders, procurement of Line Differential Protection Relays are in process and the work will be

completed by the end of June 2018.

TSGENCO mail dated 31.07.2018:

TSGENCO: Purchase Order was placed on 05.06.2018 for Procurement of Line Differential

Protection (LDP) relays and the work will be completed by the end of October 2018


Inspection of the relays is completed and the relays are received at stores. Relays are to be

drawn and commissioned. Work is expected to be completed by end of December 2018.



PendingProvision of line differential protection for Jurala line 1 & 2 (line length-1.45 KM) feeders at 220 kV Jurala HPS

[Carry-Over from Protection Audit Recommendations]

Annexure-III

Page 12 of 34

Mail received on 21-10-2015:

1) Anti-pumping contactors of all the nine 220KV Lines are in circuit and tested periodically

during AOH works of lines along with other protections.

2) Completed.

3) Possibility to use both the 220kV buses as main bus under normal operation is under review.

Mail recieved on 23-11-2015:

1) Completed

3) Two bus operation for 220kV buses : In place of existing CT switching relays, High speed

manual heavy duty change over switch of sufficient current capacity will be retrofitted to all

feeders at 220kV station and same will be operated manually during changeover of feeder by

one bus to the other and this arrangement may facilitate to put both buses in service. Time

required for this retrofit is around 90days . However, this work will be taken up only after

retrofitting of electromagnetic relays with numerical relays for Main-2 protection of all 220kV

lines, for which work is in progress.

Status received vide mail dated 10-07-2017:

1) --- Completed.

2) --- Completed. Status received vide KPCL mail dated 14.12.2017:

3) DPR for implementation of Two Bus operation for 220kV bus system has been prepared and

proposal is placed for funds from PSDF. After the approval of the DPR, the work is proposed to

be taken up.


3) KPCL informed that DPR for implementation of Two Bus operation for 220kV bus system has

been prepared and proposal is placed for funds from PSDF. After the approval of the DPR, the

work is proposed to be taken up. Time frame requested for is 2 yrs.


3) Work proposed to be taken up under PSDF. Approval from Nodal agency is awaited.

However, arrangements have been made to issue NIT.


KPCL informed that Tender would be floated in 1 month and work would be completed in 2

years.


Tender would be floated in 1 month and work would be completed in 2 years.

54/II/4 Tripping of 400 kV Raichur TPS-

Mahboobnagar line

05-04-2016 at 10:23

hrs

Line tripped on operation of Backup impedance protection of

line reactor. Direct trip was received at Mahboobnagar end.

KPCL to keep the functioning of the concerned electro-

mechanical back-up impedance protection relay under

observation, and replace it with a spare at the earliest.

KPCL Status received vide KPCL mail dated 10.07.2017:

The electro-mechanical back-up impedance protection relay is in service. However, Budgetary

offer obtained for the retrofitting of Line reactor protection with Numerical relay and is under

process

Status received vide KPCL mail dated 14.12.2017:

Tendering under process


KPCL informed that the new numerical relay for backup impedance protection of Line Reactor

would be provided by June, 2018.

KPCL Mail dated 19.01.2018:

E-tender for the retrofitting work of Line Reactor protections will be invited shortly.


Materials are received at site and works would be completed by availing the Line Shutdown in

the month of January 2019.


Materials are received at site and works would be completed by availing the Line Shutdown

approved by OCC in the month of January-February 2019

Pending

07-06-2015 at 01:35

hrs

KPCLTrippings at 220kV Raichur TPS46/II/21 Pending

Karnataka

1. KPCL to check the operation of anti-pumping relay on 220

kV side and keep it in healthy condition.

2. KPCL to provide manual reset to the 220 kV side master

trip relay.

3. KPCL to use both the 220 kV buses as main buses under

normal operation, and should go for single bus operation

only during emergencies.

Annexure-III

Page 13 of 34


1. (ii) Hot line water washing stopped and off line water washing is carried out whenever the

400 KV Unit or line is under tripped condition / Shutdown condition. --- Completed

1. (iii) Silicon coating for Unit#8 main & tie breakers carried out in Sep'16 and same is under

observation. Till today in order and good condition. For remaining breakers, since it is big order,

approval for the same is under process. --- Pending

2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker flash over protection

feature will be enabled (if available) in the numerical relays which will be retrofitted in phased

manner during R&M works.


1.(i) --- Pending

1. (ii) Hot line water washing stopped and off line water washing is carried out whenever the

400 KV Unit or line is under tripped condition / Shutdown condition. --- Completed

1. (iii) Silicon coating for Unit#8 main & tie breakers carried out in Sep'16 and same is under

observation. Till today in order and good condition. For remaining breakers, since it is big order,

approval for the same is under process --- Pending

2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker flash over protection

feature will be enabled (if available) in the numerical relays which will be retrofitted in phased

manner during R&M works --- Pending


1 (iii) As upgradation of 400kV switchyard equip's to be taken under PSDF funds, Silicon rubber

coating for breakers is deffered till then. --- Pending

2. Replacement by Num relay for Units - 5,6 & 7 completed in the month of Oct-2017. Main-I is

Seimens make and Main-II is ABB make. --- Pending


2. Replacement of Numerical relays for Units-5, 6 & 7 have been completed. Referred to OEM

for providing the Breaker flashover protection for all the breakers.


2. Reply is awaited from OEM of Numerical relays for providing Breaker Flashover protection

for all the breakers --- Pending


1. KPCL assured that porcelain insulator replacement will be taken care in tender floated for

RTPS Busbar modification --- Pending


1) i) Being discussed with other utilitis.

2) Reply is awaiting from OEM to implement the Breaker flash over protection in the Numerical

relays referring to the protection implemented in other 400KV station.

PendingKPCL13-04-2016 at 21:12

hrs

1.KPCL to undertake the following remedial measures to

avoid breaker flashovers:

(i) Replacing all porcelain insulators with composite

insulators

(ii) Carrying out hot-line water washing of all insulators on

regular basis.

(iii) Applying Room Temperature Vulcanizing (RTV) Silicone

high voltage insulator coatings to all bus-connected ceramic

insulators of equipment like CT, PT, CB, Isolators etc.

2.KPCL to take steps to provide dedicated breaker flashover

protection to all breakers at Raichur TPS at the earliest.

Y-ph Pole of Tie-breaker of Unit-4 at RTPS failed. Unit-4 got

tripped on operation of Generator Differential, Reverse

power & LBB protection. Operation of LBB protection led to

tripping of BUS-2 at RTPS

54/II/9 Tripping of 400kV Raichur TPS

Bus-2

Annexure-III

Page 14 of 34

54/II/13 Tripping of Units at 220 kV

Raichur TPS

15-04-2016 at 15:36

hrs

During testing of retrofitted distance protection in 400kV

Raichur-2 feeder, LBB protection trip DC got extended to Bus

trip. This resulted in tripping of 220kV bus at RTPS and all

connected 220 kV elements. Unit-4 which is connected to

400 kV Bus got tripped due to tripping of Station Utility

Transformer that is connected 220 kV bus

In view of the availability of two buses along with healthy

bus-coupler at 220 kV RTPS, KPCL is recommended to put in

service the double-bus operation at 220 kV RTPS by suitably

distributing loads within 15 days.

KPCL Status received vide KPCL mail dated 10.07.2017 & 14.12.2017:

Two Bus operation for 220kV bus is being carried out whenever required. However scheme for

tripping of one bus during LBB/fault and maintaining the other bus intact by tripping B/C

breaker will be taken up in R&M works.


3) KPCL informed that DPR for implementation of Two Bus operation for 220kV bus system has

been prepared and proposal is placed for funds from PSDF. After the approval of the DPR, the

work is proposed to be taken up. Time frame requested is 2 yrs.

KPCL mail dated 20.12.2018 & 23.01.2019:

Work proposed to be taken up under PSDF. Approval from Nodal agency is awaited. However,

arrangements have been made to issue NIT.

Pending

Annexure-III

Page 15 of 34


1. All logics checked and found normal. LBB timing checked and found 200msec as per KPTCL

MRT recommendation. - Completed

2. Work Under Progress ---- Pending

3. New GPS System commissioned along with new numerical and synchronised with GPS system

- Complied

4. Work Under Progress ---- Pending

Status received vide mail dated 14.12.2017:

1),3),4) Completed

2. Auto Start of DG set is taken up --- Pending


2. KPCL informed that for AMF of DG, Scheme prepared & material procurement under process.

The AMF scheme will be implemented in January 2018. --- Pending

3. The GPS system commissioned on Nov 2016 & all the numarical relay time synchronised with

GPS ---- Completed


AMF panel procurement under progress.

KPCL mail dated 20.1.2.2018:

2. AMF scheme implementation is included in the work ''Replacement common auxiliary panel

with latest technology SCADA compatibility system'' . Availing administration approval is under

progress


KPCL informed that Tender for the work would be floated by January 2019 and work would be

completed in 1 year.


1) Completed.

2) Tender for the work would be floated by February 2019 and work would be completed in 1

year....Pending

3) Completed.

4) Tender for the work would be floated by Feb, 2019, and work would be completed in 1

year....Pending

69/II/8 Tripping of 220 kV Kaiga- Kadra

line-1

06-10-2017 at 22:22

hrs

While de-synchronising of Unit-2, B-phase pole of GCB did

not open and pole descrepancy relay operated. Hence all

220KV lines CB hand tripped.

KPCL to take steps to replace the existing static protection

relays for Generator Units and Generating Transformers

(GT’s) with suitable Numerical relays at their 220 kV Kadra

PH.

KPCL Status received vide mail dated 25.07.2018:

Numerical Generator protection relay replacement proposed to be taken up alongwith SCADA

work.


Will be taken up along with SCADA work. NIT to be issued on Jan-2019


KPCL informed that Tender for the work would be floated by March, 2019, and work would be

completed in 1 year.


Tender for the work would be floated by February-2019 and work would be completed in 1

year.

Pending

72/I/4 Complete outage of 220kV

Sedam, Shahapur, Shahabad,

Kapanoor, Humnabad and

Halabarga Stations of KPTCL

01-02-2018

at 17:46 hrs

High resistance fault occurred in 110kV Sedam-Chittapur line

near Sedam end. Line DEF operated and backup OC

protection of 100MVA transformer operated at Sedam end.

But line breaker and transformer HV breaker didn’t open due

to problem in trip circuit. This resulted in cascade tripping of

upstream feeders and power supply was lost to six 220kV

stations of KPTCL.

KPCL to disable GFC protection on all lines emanating from

their generating stations.

KPCL Review Meeting on 21.12.2018

KPCL informed that compliance w.r.t. Implementing the recommendation would be furnished

soon.

Pending


Varahi power station

15-03-2018 at 22:36

hrs

There was Y-phase to ground fault on 220 kV Varahi -

Shimoga line-2. Consequent to persisting fault in ‘Y’ phase,

the breaker failure protection operated resulting in operation

of 220KV bus bar protection at Varahi, tripping all the

connected lines and Varahi running units.

KPCL to take steps to put double-bus operation into service

at their 220 kV Varahi PH.

KPCL Status received vide mail dated 25.07.2018:

Under Implementation.

KPCL mail dated 20.12.2018 & 23.01.2019:

Retrofitting of 220kV Bus Isolators is under progress. Proposed to be in service after April-2019

Pending

78/I/1 Complete Outage of 220 kV

Varahi UGPH.

24-08-2018 at 11:00

hrs

Due to suspected mal-operation of 220KV bus bar protection

at Varahi, all the connected lines and Varahi running Units

got tripped. (6 nos 220kV lines and 4 nos Varahi generating

station running Units). This resulted in complete outage of

220kV Varahi UGPH

1. KPCL to take steps to put double-bus operation into

service at their 220 kV Varahi UGPH by December, 2018.

2. KPCL to employ correct operational practices like keeping

DC fuses of B/C CB intact during bus changeover works,

disabling back-up protections of B/C CB during bus

changeover works & enabling them with proper settings only

when it is used as Main-CB of the grid elements.

KPCL KPCL mail dated 20.12.2018 & 23.01.2019:

1. Retrofitting of 220kV Bus Isolators is under progress. Proposed to be in service after April-

2019 --- Pending

2. ---- Completed.

Pending

Complete outage of 220 kV

Kadra power station of KPCL

58/I/3

(GD)

PendingKPCL1) KPCL to check settings of LBB protection in all relays from

which it was implemented, and ensure that their

configuration, logic, and timing are in order at their 220 kV

Kadra PH.

2) KPCL to furnish details regarding the existing LT auxiliary

supply arrangement at their 220 kV Kadra PH, and take steps

to provide a suitable Auto-Main-Fail (AMF) panel for DG set

to effect its auto-starting in case of failure of LT supply.

3) KPCL to ensure time-sync of all relays (DR’s & EL’s) with

GPS at their 220 kV Kadra PH.

4) KPCL to provide stand-alone Event Logger at their 220 kV

Nagjheri PH.

LBB of 220kV Kodasalli breaker at Kadra end got operated

which resulted in tripping of Bus at Kadra and in turn led to

tripping of all elements

06-09-2016

at 14:40 hrs

Annexure-III

Page 16 of 34

79/II/1 Tripping of Units- 3, 4 and 6 at

Nagjheri.

03-09-2018 at 10:11

hrs

Units # 3,4 and 6, Station Transformer and North Bus

sectionalizer at 220 kV Nagjheri PH tripped due to control DC

supply interruption. As verbally informed the control DC

supply was switched OFF inadvertently which resulted in

trippings at Nagjheri.

1) KPCL to ensure that in all the line CB (existing as well as

proposed), CTD’s, if provided with CB’s, are kept disabled.

2) KPCL to check & correct time-sync of RTU’s with GPS at

their 220 kV Nagjheri PH.

3) KPCL to ensure that their 220 kV Naghjeri PH is operated

on double bus type of bus configuration.

KPCL KPCL mail dated 20.12.2018:

1. Under review ----- Pending

2. KPTCL TC division has been requested to time-sync the RTU with NPH GPS system ----

Pending

3. Double bus system for NPH is implemented --- completed


1. Shall be discussed with SRPC.

2. KPTCL shall review.

3. Completed.

Pending


1. In view of operating 220kV Ambewadi SS in split bus mode, action is being taken up by

KPTCL. Problem in the 220kV bus coupler breaker is attended and isolator overhauling work is

under progress. Spilt bus operation at Ambewadi will be made possible at the earliest. ---

Pending

2. ICT Protection system at Ambewadi and trippings occured at Supa GS during the instance is

checked up and remedial measures already furnished in this regard.

---- Completed

Mail recieved on 29-07-2015:

1. Action is being taken by KPTCL for operating Ambewadi in split bus mode. Problem in bus

coupler breaker is attended.Isolator overhaulling work is completed.PTs are already provided

to 220kV Bus-II. After commissioning of Bus-II PTs, Ambewadi can be operated in split bus KPTCL Mail dated 16.12.2017 & Review Meeting dated 19.12.2017:

1. Recommended works at Ambewadi have not been taken up due to various problems faced

due to poor response from the turn key agency M/s ERL. A site meeting is planned during this

month to discuss about further plan of action for attending SRPC recommendations pertaining

to the Sub station.

The issue was discussed in the review meeting. Considering the importance of the substation

and delay in executing the works, it was decided to escalate all pending issues relating to

Ambewadi SS to KPTCL top Management for early completion.


1. The outstanding protection issues pertaining to Ambewadi were appraised to the

management and proposal for construction of new GIS SUb stations has been approved by

KPTCL management. In view of attending protection audit recommendations pertaining to

Ambewadi SS without linking with new Station proposal, action has been taken to include the

works in extended scope of R&U project awarded to M/s GE T&D India Limited. Addition

materials required are yet to be supplied by M/s GE.


Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being

taken to restore the carrier protection for 220kV Sedam-Tandoor line. AR will be enabled.


1. Procurement of Bus bar and LBB protection is in the final tendering stage.

2. Action is being taken to restore the carrier protection for 220kV Sedam-Tandoor line. AR will

be enabled after restoration of PLCC.

KPTCL mail received on 23-01-2016:

1. Bus bar protection panels pocured and erected at Sedam. Wiring , testing ,commissioning is

being taken up.Planned to complete by April 2016.



KPTCL Mail recieved dated 22-11-2017:

1 & 2). Bus Bar Protection panel and required Wave traps are supplied under R&U. Wave trap

to be commisioned in Tandoor line and PLCC to be restored.Once PLCC is restored AR will be

enabled. The Wave traps required are supplied under R&U project and the same is to be

commisioned at Sedam end for restoration of PLCC.


1 & 2) Replacement of Bus Bar Protection is included under R&U project. Awarded to M/s GE

Ltd. Panels have alredy been supplied by the Agency. The work will be taken up on top priority.


KPTCL informed that the works relating to put A/R in service are going on at their Sedam SS,

and assured that it would be put into service by February, 2018.


1). Bus Bar Protection Work is under progress. Work will be completed in 2 months.

---- Pending

2). ---A/R was enabled from Sedam end on 03.11.2018 ----Completed.

PendingKPTCLTriggering incident was B-phase to earth fault in 220kV

Ambewadi- Nagzari line-1. B-pole of breaker did not open at

Ambewadi end. LBB protection not available at Ambewadi

end. All elements tripped on Zone-2 from remote ends.

22-12-2014

at 21:22 hrs

R-Phase to ground fault occurred on 220kV Sedam-Shahpur

line. Fault not cleared from Sedam end due to stuck-breaker

condition. While the Sedam- Sahapur line tripped from

Shahapur end in Zone-1, the other 220 kv lines from Sedam

tripped at remote ends in Zone-2. This caused complete

outage of 220kV Sedam substation.

1. Till the completion of R&M works for bus bar and LBB

protection, KPTCL shall explore the possibility of having split

bus operation at Ambewadi and submit the details of the

same to PCSC forum.

2. KPTCL shall provide the details of the tripping of Supa

hydro station connected downstream from 110 kV bus.

27-01-2015 at 8.00

hrs

Complete outage at 220kV

Sedam Substation of KPTCL (GD-

1)

KPTCL

GD-1 at 220kV Ambewadi

Station of KPTCL

1. KPTCL to provide Bus bar and LBB protections for 220 kV

bus at Sedam S/s.

2. KPTCL to implement A/R feature on 220 kV Sedam-

Tandur inter-state line.

40/I/1

41/I/4 Pending

Annexure-III

Page 17 of 34


Sedam substation of KPTCL

15-02-2015

at 14:24 hrs

Fault occurred in 220kV Sedam-Shahpur line 1. KPTCL to provide Bus Bar protection and LBB protection at

Sedam S/s and furnish the status of their implementation to

PCSC forum.

2. KPTCL to implement A/R feature on 220 kV Sedam-Tandur

inter-state line.

KPTCL Mail received on 27-05-2015:

1. Bus Bar protection will be provded under R&U.

2. A/R yet to be enabled.





KPTCL Mail Recieved dated 22-11-2017:

Bus Bar Protection panel and required Wave traps are supplied under R&U. Wave trap to be

commisioned in Tandoor line and PLCC to be restored.Once PLCC is restored AR will be

enabled.


1. Replacement of Bus Bar Protection is included under R&U project. Awarded to M/s GE Ltd.

Panels have alredy been supplied by the Agency. The work will be taken up on top priority.

2. AR feature will be enabled during retrofitting of Main-2 relays.


1 & 2) KPTCL informed that the works are under progress and are targeted to be completed by

February, 2018.


1). Bus Bar Protection commissioning works under progress. Work will be completed in 2

months.

2). Attended. --- Completed

Pending





KPTCL Mail Recieved dated 22-11-2017 & 16.12.2017:

1.Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and

Ambewadi-Xeldom lines are radial lines, it was decided that enabling AR is not required. To

clear the faults in the abovelines early, the timings of the Zone 2 was reduced to 150mS and the

Back Up EFR timings have been reducedto 150mS. --- Completed

2.The planned works as per R&M could not be taken up due to the problem with the vendor

and could not be taken up under R&U project due to administrative reasons. ---- Pending


2. The issue was discussed. Considering the importance of the substation and delay in

executing the works, it was decided to escalate all pending issues relating to Ambewadi SS to

KPTCL top Management for early completion.


The protection issues pertaining to Ambewadi was appraised to the management and

proposal for construction of new GIS SUb stations has been approved by KPTCL management.

Further as per SRPC directions and in view of attending protection audit recommendations

pertaining to Ambewadi SS without linking with new Station proposal, action has been taken to

include the works in extended scope of R&U project awarded to M/s GE T&D India Limited.

Addition materials required are yet to be supplied by M/s GE. work expecnted to be completed

in 5 months.

12-03-2015 at 7:51

hrs

KPTCL1. KPTCL shall provide A/R feature on Ambewadi – Ponda 220

kV D/C inter-state line.

2. Till the completion of R&M works for bus bar and LBB

protection, KPTCL shall explore the possibility of having split

bus operation at Ambewadi and submit the details of the

same to PCSC forum.

Fault in 220kV Ambewadi-Nagjheri line-2Complete outage of 220 kV

Ambewadi substation of KPTCL

42/I/2

(GD)

Pending

Annexure-III

Page 18 of 34

48/I/3 Outage of 220kV Ambewadi

station in Karnataka

30-09-2015 at 10:41

hrs

220kV Ambewadi-Nagjheri line-2 tripped on B-phase to earth

fault. This resulted in loss of supply to 220kV Ambewadi bus.

220kV Ambewadi-Ponda line-1&2 were hand tripped after

deenergization of bus at Ambewadi.

KPTCL to fast-track providing A/R on all 220 kV lines

emanating from Ambewadi SS to prevent Station shut-down

on temporary faults.

KPTCL KPTCL mail received on 23-01-2016:

Will be complied in a months time.


Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and



Back Up EFR timings have been reducedto 150mS.


Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and



Back Up EFR timings have been reduced to 150mS. In view of the above, it is requested to drop

the issue from this list.


KPTCL informed that AR would be enabled at Ambewadi end for lines other than Ponda and

Xeldom lines during retrofitting of Back Up protection by Distance protection relay at

Ambewadi.

Considering the importance of the substation and delay in executing various works, it was

decided to escalate all pending issues relating to Ambewadi SS to KPTCL top Management for

early completion.

Pending


The protection issues pertaining to Ambewadi was appraised to the management and

proposal for construction of new GIS SUb stations has been approved by KPTCL management.

Further as per SRPC directions and in view of attending protection audit recommendations

pertaining to Ambewadi SS without linking with new Station proposal, action has been taken to

include the works in extended scope of R&U project awarded to M/s GE T&D India Limited.

Addition materials required are yet to be supplied by M/s GE. work will be completed in 5

months

KPTCL Mail received dated 25-05-2016:

SEE, RTC, Bangalore to update the status


Providing numerical bus bar protection to 400kV buses and GPS time synchronising equipment

at Guttur is considered under R&U. Work is awarded to M/s Alstom, execution will be taken up

shortly.


GPS and accessories will be supplied during May 2017, expected to complete the work within a

month after supply of materials.


As discussed during the earlier PCSC meetings, current limit of 12.5KA has been added in the

logic of AR at Guttur end to prevent reclosing during failure of LA or any other very close faults.

Replacement of existing static BBP by new numerical BBP with Main 1&2 will be taken up at

Guttur for which the panels are already supplied. Presently, replacement of 220KV side Bus bar

protection is under progress. DI for delivery of GPS receiver has already been issued, but there KPTCL Mail dated 16.12.2017:

1). The work of replacing static type 400kV Bus Bar Protection scheme by numerical BBP is

under progress at Guttur.

--- Pending

2). GPS time syncronising device is expected to be supplied before end of December 2017 ---

Pending


1) & 2) KPTCL informed that the works are under progress, and are targeted to br completed by

February, 2018.


GPS time synchronisaionis provided for protection relays under R&U project. Replacement of

400kV BBP by numerical BBP is envisaged under R&U works. Additional quantity of controls

cables required to take up the BBP replacement work. Supply of control cables awaited.


1. Replacement of static BBP provided to 400kV side by numerical BBP and the work of

providing DR/ EL collection system is under progress. Work will be completed in 3 months -----

Pending

2. GPS time synchronising equipment already commissioned.

--- Completed.

17-01-2016 at 18:53

hrs

Multiple tripping at 400kV

Guttur SS

KPTCL 1. KPTCL to configure all DR’s and EL’s at 400 kV Guttur SS so

that they will also get triggered for BBP operation.

2. KPTCL to ensure time-synchronization of all DR’s and EL’s

with GPS at their 400 kV Guttur SS.

51/II/21 Failure of Lightning Arrestor of Y-phase Line Reactor of 400kV

Guttur-Hiriyur line-1 and line tripped on distance protection

Zone-1. Bus-bar protection of 400kV Bus-2 at Guttur

substation also got operated during the event sensing this

through fault. 400/220 kV ICT-1 & 2 at Guttur, 400kV Kaiga-

Guttur-2, 400kV

Guttur-Narendra-2, 400kV Guttur-Hiriyur-2 and 400kV Guttur-

Munirabad which are on 400kV Bus-2 got tripped during the

incident. 400kV Guttur-Narendra-1 which was on Bus-1 also

tripped at the same time.

Pending

Annexure-III

Page 19 of 34


Replacement of existing BBP by new BBP with 4 zone protection is being taken up under R&U.


GE Ltd has already supplied the necessary Bus Bar protection panels for replacement of the

existing static type BBP by new numerical BBP with 4 zone protection under R&U project. The

work of commissioning the same will be taken up shortly.


Due to operational constraints two/ multi bus operation is not being implemented.


It was noted that Shimoga SS is having required configuration for providing double-bus

operation. However, due to large no. of feeders (15 in no) with variable gneration at certain

remote ends like Varahi, the flows on these lines are bound to vary. As such it is necessary to

zero in on appropriate arrangement of feeders on different buses so that bus-isolators of the

feeders are not overloaded.

The issue was discussed. KPTCL was asked to try out multi-bus operation on trial basis to arrive

at suitable arrangement of feeders.


Bus sectionaliser breakers have to be provided for operating Shimoga in multi bus mode.

Estimates have to be prepared by CEE,TZ,Hassan. Work expected to be completed in 1 year.


1. The necessary Bus Bar protection panels are already supplied to Chikkodi under R&U project.

Presently R&U works at sub stations subjected to audit are taken up. After completion of PAR

works, the baove works are planned.

--- Pending

2. --- Pending

3. --- Pending


1.The necessary Bus Bar protection panels are already supplied to Chikkodi under R&U project.

Control cables have to be supplied. Presently R&U works at sub stations subjected to audit are

taken up. After completion of PAR works at 26 Sub stations, remaining works will be taken up

through M/s GE.

--- Pending.

2. --- Pending

3. --- Pending


1. KPTCL informed that BBP would be provided by April, 2018.

---- Pending

2. KPTCL informed that DPR settings had been reviewed.

---- Completed

3. EFR on failure of B-ph PT of 220 kV Bus-2 had been furnished to CEA. ---- Completed


1). Bus Bar Protection work is included under R&U. work expected to be completed in 3

months ---- Pending

2). Major equipment failure reports are being sent to CEA regularly ---- Completed.

220kV Bus Bar protection operated during failure of R phase

CT in DVG-2 line bay.

22-02-2016 at 15:03

hrs


Shimoga substation

57/II/1 Pending01-07-2016 at 03:03

hrs

KPTCL1.KPTCL to take steps to provide busbar protection at their

220 kV Chikkodi inter-regional substation, and furnish a time-

line for the same.

2.KPTCL to review distance protection settings for 220 kV

Chikkodi – Kudachi line.

3.KPTCL to furnish equipment failure report of the current

incident to PSE&TD Division of CEA with a copy marked to

SRPC.

Triggering incident was failure of B-ph PT of 220kV Bus-2

(western bus) at 220KV Chikkodi substation. 220KV Chikodi-

Belgaum-I line tripped on DEFR (Inst), 220KV Chikkodi-

Kudachi line tripped on Distance protection and also 100MVA

transformer-2 tripped on E/F protection.

PendingKPTCLKPTCL to operate 220 kV Shimoga on multi-bus operation

under normal conditions, and put it on single-bus operation

only under emergency conditions.

52/I/3

Tripping of 220 kV Chikkodi-

Mudshingi and 220 kV Chikkodi-

Talandage lines

Annexure-III

Page 20 of 34

KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works.


1. Numerical Bus Bar protection panels have already been supplied as a part of R&M works

awarded to GE Ltd. Due to issue regarding the sectionaliser CTs, the work had stopped. Now

the same is resolved and the the above work will be taken up after supply of sectionaliser CTs. --

- Pending

2. --- Pending


1. Numerical Bus Bar protection panels have already been supplied as a part of R&M works

awarded to GE Ltd. Due to issue regarding the sectionaliser CTs, the work had stopped. Now

the same is resolved and the the above work will be taken up after supply of sectionaliser CTs. --

- Pending

2. --- Pending


1. KPTCL informed that BBP at 220 kV Hoody would be provided by March, 2018.

---- Pending

2. EFR on failure of R-ph CT of 220/ 66 kV Transformer-2 had been furnished to CEA. ----

Completed


1). The R&M work of 220kV Hoody SS is under progress and expected to be comleted before

the end of August 2019. Providing Bus Bar Protection to 220kV buses is a part of R&M work at

Hoody ----- Pending

62/II/5 Tripping of 220 kV South Bus

and connected elements (220kV

HSR, 220kV Nagnathpura, 220 kV

Harohalli, 220 kV

Subramanyapura, 220 kV

Tataguni, 220 kV Mallur and

400/220kV ICT-2 and 3) at

400/220kV Somanhalli

substation of KPTCL

(Load loss: 850 MW)

20-01-2017 at 14:34

hrs

Triggering incident was fault in 66 kV Somanahalli -

Bannerghatta line and fault was cleared by operation of Back-

up OCR at Somanahalli end.

KPTCL to provide numerical Busbar Protection at their 220 kV

Somanahalli SS at the earliest.

KPTCL KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works


Tesing & Commissioning of numerical BBP at Somanahalli is under progress. There was some

technical issue wth BBP scheme supplied to Somanahally which is being finalised in

consultation with OEM SIFANG. Numerical BBP will be commissioned at Somanahally within a

month's time.


Numerical Bus Bar protection Scheme will be commissioned at Somanahally before end of

December 2017.


The work of providing Bus Bar Protection to 220kV buses is incuded under R&M works

envisaged at Somanahally. The R&M work is expected to be completed before end of March

2019 ----- Pending

Pending


Ambewadi station

02-04-2018 at

13:46hrs

Loss of supply occurred to 220 kV Ambewadi station due to

tripping of 220kV Nagzhari-Ambewadi line-2 (Source) from

Nagzhari power station. After bus dead, Ambewadi-Ponda

lines – 1 & 2 were hand-tripped. In antecedent conditions,

220kV Ambewadi - Nagjheri ckt-1, 220kV Ambewadi-

Narendra Ckt-1 &2 were out of service.

1). KPTCL to review operation of SPS at NPH for proper

functionality and changed network conditions (reduction of

generation with tripping of evacuating lines) and put it into

service at the earliest.

2). KPTCL to furnish equipment failure report of the current

incident (R-phase CT in Nagjheri – 1 bay at Ambewadi SS) to

PSE&TD Division of CEA with a copy marked to SRPC.

KPTCL KPTCL mail dated 20.12.2018:

1). To be reviewed. Expected to be completed in 1 month.---- Pending

2), Being followed ----- Pending

Pending

74/II15 Multiple Trippings at 400/220kV

Guttur station

21-04-2018 at 12:50

hrs

Triggering incident was fault in 220 kV Davanagare - Shimoga

line. Bus bar protection operated at Guttur resulting in

tripping of all the connected elements. 220 kV Guttur was on

single bus operation due to CVT problem in Bus-2.

KPTCL to put double-bus operation at their 220 kV Guttur

substations by attending to Bus-2 CVT problem.

KPTCL KPTCL mail dated 20.12.2018:

Bus-2 CVT problem is attended. However due to breaker replacement works, 220kV side

operated in single bus mode.


KPTCL informed that double-bus operation at their 220 kV Guttur would be provided within

two months.

Pending

79/III/9 Tripping of 400 kV JSWEL

–Guttur line

29-09-2018

at 11:30 hrs

R-phase to earth fault occurred in line. Auto-reclose was not

attempted at JSWEL due to DT receive. At Guttur end auto-

reclose could not be validated with DR/EL.

KPTCL to furnish a detailed report on tripping event bringing

out reasons for DT sending from Guttur end to JSWEL on 400

kV Guttur - JSWEL line along with remedial action taken to

PCSC forum.

KPTCL Review Meeting on 21.12.2018:

KPTCL was aksed to furnish status of implementation of the recommendation given at the

earliest.

Pending

80/II/7 Tripping of 400 kV JSWEL-Guttur

line

17-10-2018 at 02:04

Hrs

Triggering incident was R-phase to earth fault in line. At

Guttur end there was operation of pole discrepancy and

resulted on tripping of Y & B pole after a duration of 2

seconds from the occurrence of fault. FIR, DR & EL of Guttur

end were not furnished.

KPTCL to examine the reasons for sending of DT from Guttur

end to JSWEL end, and furnish an action taken report

including remedial measures taken to rectify the same.

KPTCL Yet to be informed Pending

09-01-2017

at 23:06 hrs

Tripping of 220 kV Bus 2 and

connected elements (220kV HAL

#1 and 2, 400/220 kV ICT- 1, 2

and 220/66 kV ICT-2) at 400/220

kV Hoody substation of KPTCL

(Load loss : 590 MW)

62/II/3 PendingKPTCL1. KPTCL to provide Busbar protection at their 220 kV Hoody

SS at the earliest.

2. KPTCL to furnish an Equipment Failure Report on CT failure

to CEA with a copy marked to SRPC.

Failure of R-phase CT of 220/ 66 kV transformer-2 at 220kV

Hoody end resulted in a bus fault in 220kV Bus-2. Fault was

cleared by backup protection of ICT's (220kV lines were being

radially operated) due to absence of busbar protection

Annexure-III

Page 21 of 34


Ambewadi Substation of KPTCL

29.10.2015 at 14:34

hrs

220kV Nagjheri-Ambewadi line-1 tripped at 13:33 hrs due to

B phase to earth fault. Ambewadi was radially fed from

Nagjheri power station through 220kV Nagjheri-Ambewadi

line-2. Tripping of this line caused 220kV Bus shut down at

Ambewadi and remaining lines and transformers were hand

tripped

1. KPCL to provide A/R on all 220 kV lines emanating from

Nagjheri PH.

2. KPTCL to provide A/R on all 220 kV lines emanating from

Ambewadi SS.

KPCL/ KPTCL KPTCL Mail Recieved dated 22-11-2017:

1. coordination of KPCL has been requested for enabling AR lines terminated to Nagajari.

2. AR will be enabled at Ambewadi end for lines other than Ponda and Xeldom lines during

retrofitting of Back Up protection by Distance protection relay at Ambewadi.

KPTCL Mail dadted 16.12.2017 & Review Meeting dated 19.12.2017:

1. KPTCL informed that Coordination of KPCL has been requested for enabling AR lines

terminated to Nagajari.

--- Pending

2. KPTCL informed that AR would be enabled at Ambewadi end for lines other than Ponda and

Xeldom lines during retrofitting of Back Up protection by Distance protection relay at

Ambewadi. -- Pending


2). Readiness from KPTCL for implementing AR is already confirmed to KPCL. Decision pending

from KPCL end.


1). KPCL informed that A/R will be provided on all 22 kV lnies emmanating from Nagjheri PH

within 3 months time ----- Pending

Pending

Status informed during Special Meeting held on 03.06.2016:

1. KPTCL informed that the matter had been taken up with concerned Line Operation and

Maintenance wing to carry out corridor clearance and maintenance as per schedule to avoid

frequent line faults in this corridor. A letter had also been addressed to Chief Engineer,

Bhagalkot zone, to ensure lines in & around Kali complex are maintained in healthy condition. ---

Completed

2. KPTCL assurd that the final modified SPS would be implemented at Nagjheri PH at the

earliest. ------ Pending

3. KPCL informed that Nagjhari- Kodasalli Lines 1 & 2 had been kept in service since 23.05.2016

@ 08.06hrs.

--- Completed

KPTCL Mail received dated 28-06-2016:KPTCL Mail dated 16.12.2017:

1) & 3). --- Completed.

2). Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be

discussed and approved by the SRPC forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested certain changes for

suitable incorporation. KPTCL agreed to look into the same and assured that the modified SPS

would be furnished by January, 2018.


2. KPTCL informed that Nagjheri SPS shall be finalised in 1 month.


1) .....Completed


3) .....Completed

51/I/3 220kV lines from Nagjheri power house started tripping from

11:00 hrs due to fault in lines. The sequence of tripping is

shown in SOE list. At 12:33 hrs, 220kV Narendra-Ambewadi

lines-1&2 got tripped which resulted in loss of evacuation

path to Nagjheri station resulting in tripping of running Units

and complete outage at Nagjhheri power station. 220kV

Ambewadi station also got de-energized due to tripping of

source feeders i.e. 220kV Narendra-Ambewadi-1&2 and

220kV Nagjheri-Ambewadi-1&2.

22-02-2016 at 12:36

hrs


Nagjheri power station and 220

kV Ambewadi substation of

KPTCL

Pending 1. To avoid tripping of transmission lines on transient faults,

KPCL/ KPTCL is recommended to carry out periodic patrolling

of lines, and ensure their proper maintenance by carrying out

jungle/ bushing clearance and trimming of tree branches

within the RoW of transmission lines as per the SRPC

transmission line patrolling guidelines (available under the

menu item "All Uploads/ Operation/ Miscellaneous/

Transmission Line Patrolling Protocol / Guidelines for

Southern Region" on SRPC website).

2. KPCL/ KPTCL to review operation of SPS at NPH for

functionality (reduction of generation with tripping of

evacuating lines) and healthiness.

3. KPCL to put 220 kV Kodasalli - Nagjheri D/C lines into

service if more than 200 MW generation from Kali Complex

(with Nagheri Contribution not less than 50 MW) is ensured

on sustained basis.

KPCL/ KPTCL

Annexure-III

Page 22 of 34


1) …Completed.


3) …Completed.

Tamil Nadu

25-01-2017 at 22:36

hrs

PendingTANGEDCO mail dated 15.04.2017:

1) New Relay is tested and ready for replacement.Now all 5 units are in service.The relay will be

replaced when lesser units are in service. --- Pending

2.a)Steps are taken to renovate & mordernization of all the control panel into Numerical based

control panels. --- Pending

2.b) Since 230 KV indoor switchyard has no spare space providing dual CT`s is not fessible. --

Completed

3) Procurement of EL & DR is under progress. --- Pending

TANGEDCO mail dated 26.04.2017:

1) Check zone New Relay is replaced on 17.04.2017 -- Completed.

2. --- Pending

3. --- Pending

TANGEDCO mail dated 13.12.2017:

2).P & C wing gives clearance to TTPS to procure the Bus bar protection relays and protection

relays and SER / DR system vide Lr.CE/P&C/SE/D/EEPC4/AEE3/F.TECH/D.27/17 Dated:

05.10.2017. To get administrative approval budgetary offer has bar protection relay from

various companies ----Pending

3). SRPC vide Lr: SRPC/SE- III/CEA/2017/6450/DT:27.10.2017 gives features of SER/DR.

Budgetary offer will be called for SER / DR having above features. ---Penidng


2) & 3) The issue was discussed and TANGEDCO was asked to provide time-line for

implementing the recommendations.

Mail dated 29.01.2018:

Procurement work is under progress and will be completed by December 2018.


TANTRANSCO informed that Tender would be floated by January 2019 and Procurement is

expected by APril 2019. Works would be completed by December 2019.

TANGEDCOFailure of Bus Section-I Y-ph CT resulted in operation of bus-

bar protection for Bus Sections -I & II. Running Units#1, 4 and

5, 230 kV Kayathar, 230kV Kudankulam, 230kV Sterlite,

Station Transformer-1, 2 & 3 got tripped during the incident.

Unit – 2 & 3 were not in service.

Tripping of running Units &

230kV feeders at Tuticorin TPS

of TANGEDCO

(Gen Loss: 640 MW)


Modifications to be carried in Nagzari SPS logic is submitted to SRLDC/SRPC for verification

and approval


1. Tripped since there was evacuation problem and there were only two lines NA-1 and NA-2 ---

- Completed

2. Will be reviewed in consultation with EE(RT), KPTCL, Hubli. --- Pending

3. Both the lines are in charged condition. --- Completed.


2. Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be

discussed and approved by the SRPC forum. --- Pending


1) & 3). --- Completed.

2). Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be

discussed and approved by the SRPC forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested certain changes for

suitable incorporation. KPTCL agreed to look into the same and assured that the modified SPS

would be furnished by January, 2018.


KPTCL informed that Nagjheri SPS shall be finalised in 1 month.

KPCL/ KPTCLComplete outage of 220kV

Ambewadi station of KPTCL and

220kV Nagjheri of KPCL

18-03-2016 at 14:40

hrs

Ambewadi Narendra line-2 tripped on fault and 220kV

ambewadi Narendra line-1 tripped due to over-loading.

Running Units at Nagjheri also tripped during the event due

to tripping of evacuating lines

1. KPCL to furnish a report on the reasons for Unit-6 tripping

at Nagjheri PH.

2. KPCL/ KPTCL to modify suitably the SPS at Nagjheri Power

House such that it would also factor in the over loading of

Ambewadi-Narendra lines.

3. KPCL to put 220 kV Kodasalli - Nagjheri D/C lines into

service if more than 200 MW generation from Kali Complex

(with Nagheri Contribution not less than 50 MW) is ensured

on sustained basis.

Pending

62/II/7 1. TANGEDCO to replace existing Check-Zone relay with a

new one possessing required performance.

2. TANGEDCO to take steps to provide numerical busbar

protection at their 220 kV Tuticorin TPS. TANGEDCO may also

explore providing dual CT’s (on either side) for all B/S

breaakers at the time of commissioning of numerical BBP, if

there were no space constraints.

3. TANGEDCO to take steps to provide for standalone Event

Logger (EL) and standalone Disturbance Recorder (DR) with

automatic downloading facility to a centralized server.

53/I/3

Annexure-III

Page 23 of 34

TANTRANSCO Mail received on 19-02-2016 and 24-03-2016:

Revision of Bus Bar Protection setting was carried out. The stabilizing voltage setting was

raised from 410 to 450 volts. After completing the necessary test, the bus bar protection put in

to service on 29.12.2015.

Mail Received on 27-04-2016 ,16-06-2016,25-07-2016 & 24-09-2016:

Revision of Bus Bar Protection setting was carried out. After completing the necessary test, the

bus bar protection put in to service on 29.12.2015.

Mail received on 10-11-2016 & 20.12.2016:

Provision of Bus Coupler bay arrangement was included in the Upgradation works proposed and

the same was sanctioned by MoP through PSDF.

Numerical relay allotted and being commissioned.


Numerical BBP relay was commissioned on 02.02.2017

Status received vide mail dated 12.04.2017 & 01.06.2017 & 15-06-2017:

Numerical BBP relay was commissioned on 02.02.2017.

Provision of Bus Coupler bay arrangement was included in the Upgradation works proposed and

the same was sanctioned by MoP through PSDF.


Numerical BBP relay was commissioned on 02.02.2017.Status received vide mail dated 18-09-2017 & 31-20-2017:

Numerical BBP relay was commissioned on 02.02.2017. Provision of CT in Bus Coupler bay is

arranged and zone segregation will be provided.

Status received vid email dated 12-12-2017:

Numerical BBP relay was commissioned on 02.02.2017. Provision of CT in Bus Coupler bay has

been allotted. Zone segregation will be provided after commissioning of CT.


TANTRANSCO informed that the recommendation would be complied with by March, 2018.

TANTRANSCO Mail received on 25-01-2018:

Provision of CT in Bus Coupler bay is arranged and zone segregation will be provided. Timeline:

March-2018.

TANTRANSCO MAIL DATED 22.05.2018 & 08.06.2018:

Bus coupler bay equipments allotted will be commissioned by Aug 2018


Commissioning of CT in Bus Coupler bay is under progress


Commissioning of CT in Bus Coupler bay is under progress Will be completed by Oct.2018.


Civil work completed & CT will be commissioned after strengthening Bus .2 conductor

jumpers.Awaiting Bus LC Time line before January 2019.


Erection under progress will be completed before 31.01.2019

Pending21-12-2015 at 6:28

hrs


Mywadi station of TANTRANSCO

Busbar protection got operated for a fault in 230kV Mywadi-

Anaikadavu line

TANTRANSCO to examine the feasibility of providing two

main-zone operation for bus bar protection by exploring

various alternatives like replacing existing bus-coupler CB

with a hybrid bus-coupler CB that comes with inbuilt CT,

replacing existing BBP relay with another suitable relay that

supports two main-zone operation, and implement the same.

TANTRANSCO

Annexure-III

Page 24 of 34

TANTRANSCO mail received on 25-01-2018:

1) Commissioning of Bus Coupler CT, Extended Bus with Additional Bus Coupler is under

progress. Timeline: June-2018.

2) Numerical BBP commissioned on 29.08.2017 to enable Bus seggregation.

3) Providing Re-Trip feature for LBB will be studied.


Providing new Bus coupler bay involes bay shifting work.work awarded and under progress.

Time line. Dec2018.



Time line. Dec2018.



Time line. Dec2018.


Bus coupler erected and commissioning schedule on 18.12.2018.


1. Bus coupler errected and commissioning would be completed by January 2019 --- Pending

2. -----Completed

3. Works would be completed by Janaury, 2019 --- Pending.


work under progress & will be commissioned on or before 31.01.2019

Mail recieved on 25-07-2016 & 24-09-2016:

TANTRANSCO: Auto Transformer-2 HV side Bus isolator 'C'-phase support insulator of 230kV

Southern Bus was replaced and Bus Bar Protection scheme was restored on 12.05.2016.

Status received vide mails received on 10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 &

15-06-2017 & 04.08.2017 & 18.09.2017:

CT is not available in the Bus Coupler bay for zone segregation. CT latch relay is to be provided

for all bays for zone segregation.

Status received vide mails received on 31-10-2017 & 12-12-2017:

Numerical Bus bar protection panel allotted and will be commissioned with zone segregation..


TANTRANSCO informed that Numerical BBP would be commissioned by March, 2018.


Commissioning of Numerical Bus bar protection is under progress. Zone segregation will be

ensured. Timeline: March-2018.

PendingTANTRANSCO mail received on 24-03-2016:

CMR relay for extending LBB protection was released and LBB extended from Distance

Protection relay directly. CT is not available in the Bus Coupler bay for zone segregation.

However, during commissioning of third ICT, Bus section Breaker will be provided for zone

segregation. Numerical BBP relay will be provided.

Status received vide mails recieved on 27-04-2016 and 20-05-2016 ,16-06-2016, 25-07-2016, 24-

09-2016,10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 & 15-06-2017:

1 & 2) CT is not available in the Bus Coupler bay for zone segregation. However, during

commissioning of third ICT, Bus section Breaker will be provided for zone segregation.

Numerical BBP relay will be provided.


1 & 2) Contract awarded for providing third ICT & Bus modification works to accomodate bus

coupler bay. Numerical BBP relay has been provided and tesing under progress.



coupler bay. Numerical BBP relay has been provided and tesing under progress.



coupler bay.

Pending TANTRANSCO to take steps to provide double-bus operation

at their 230 kV Gummidipoondi SS.

TANTRANSCO

51/I/1

(GD)

Complete outage of 230kV

Madurai S/s (Chekanaurani) of

TANTRANSCO

19-01-2016

at 11:56 hrs

Fault had occurred in 230kV Madurai-Sembatty line. Trip

from distance relay was not extended to breaker due to

protection DC fail. LBB protection got operated resulting in a

busbar trip at 230kV Madurai substation. All elements got

tripped as there is a single bus operation at 230kV Madurai

S/s

1. TANTRANSCO to provide split-bus operation with bus

sectionalizer CB for their 230 kV Madurai (Chekanurani) SS.

2. TANTRANSCO to provide two main-zone operation for the

numerical BBP that is being commissioned.

3. TANTRANSCO to examine the feasibility of providing Re-

Trip feature for the LBB protection, and accordingly take

steps for implementing the same.

TANTRANSCO

55/I/1

(GD)


Gummidipoondi Station of

TANTRANSCO

12-05-2016 at 12:15

hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV Southern Bus

occurred at Gummidipoondi station. At the time of fault, Bus

bar protection relay was not in service for pre-commissioning

testing of Auto Transformer-2. All feeders got tripped due to

operation of zone-2 protection from remote ends.

Annexure-III

Page 25 of 34


Numerical Busbar protection relay commissioned on 14.05.2018


Control & Status of isolator feedeback to be provided by replacement of Drive Mechanism box.





Timeline requested upto Dec 2018.


1. TANTRANSCO: Estimate sanctioned for replacement of defective isolator status feedback.

Work under progress. Lightning mask work under progress will be completed within three days.


TANTRANSCO informed that Double bus operation would be provided by March, 2019.


Isolator status will be ensured by March 2019

Pending TANTRANSCO to take steps to provide double-bus operation

at their 230 kV Gummidipoondi SS.

TANTRANSCO55/I/1

(GD)


Gummidipoondi Station of

TANTRANSCO

12-05-2016 at 12:15

hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV Southern Bus

occurred at Gummidipoondi station. At the time of fault, Bus

bar protection relay was not in service for pre-commissioning

testing of Auto Transformer-2. All feeders got tripped due to

operation of zone-2 protection from remote ends.

Annexure-III

Page 26 of 34

The issue was discussed in PCSC-58 meeting held on 18.10.2016, when PCSC forum agreed to

de-link the implementation of the Item from the scope of Protection Audit Recommendations

(PAR), and pursue it as part of PCSC Recommendations.

Status received vide mails dated 10.01.2017 & 12.04.2017 & 01.06.2017 &15-06-2017 &

04.08.2017 & 18.09.2017 & 31-10-2017& 12-12-2017:

Different make Relays will be provided for Main-I & II relays at Sunguvarchatram end in a

phased manner.


TANTRANSCO informed that the recommended works of providing different make Relays for

Main-I & Main-II are targeted to be completed by September, 2018.



phased manner. Timeline: September-2018.


TANTRANSCO informed that the recommended works of providing different make Relays for

Main-I & Main-II are targeted to be completed by September, 2018.


provision of Different make Relays for Main-I & Main-II will be completed by September,

2018.







TANTRANSCO MAIL DATED 11-12-2018:


phased manner. Timeline: September-2019



phased manner. Timeline: September-2019

14-09-2016 at

11:13Hrs

Bus Bar Protection (Zone-2) of 230 kV Bus-B got operated at

Alamathy Station during fault in 230 kV Alamathy-Korattur

feeder.

58 Different type and Make of distance protection relays to be provided for Main-I & Main-II protection for 230kV feeders at 400 kV Sunguvarchathiram & 230 kV Sunguvarchathiram

Substation [Carry-Over from Protection Audit Recommendations]

TANTRANSCO Pending

Mail received on 10-11-2016 & 20.12.2016:

1. The Bus Bar Protection scheme will be tested for healthiness including the CT circuits.

2. High impedance BBP relay will be replaced by Numerical relay.

Status received vide mails dated 10.01.2017 & 12.04.2017 & 01.06.2017 & 15-06-2017:

1. The Bus Bar Protection scheme was tested for healthiness including the CT circuits. AREVA

make CTs in Alamathy SS are having different kneepoint voltage for the cores. CT cores of

higher knee point voltage has been choosen for BBP in 230kV Korattur, 230kV OPG-1 & 230kV

OPG-2 feeders on 29.11.2016. ---- Completed.

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending,

Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017 & 12-12-2017.

1. ---- Completed

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending


2) TANTRANSCO informed that Numerical BBP would be provided by April, 2018 ---

Pending


1. --- Complied.

2. High impedance BBP relay will be replaced by Numerical relay. Timeline: April-2018.

TANTRANSCO MAIL DATED 22.05.2018 & 08.06.2018 & 23.07.2018:

2.Numerical BBP relay will be provided. Timeline: Sep-2018.


1. Complied


Multiple tripping at 230 kV

Alamathy Station

1. TANTRANSCO to check the healthiness of BBP relay by

conducting stability test, and take appropriate remedial

action like increasing voltage settings, ensuring the

healthiness of CT’s, using CT’s with similar characteristics

(equal saturation effects & equal winding resistances) etc. at

their 230 kV Alamathy SS.

2. TANTRANSCO to replace the existing high-impedance BBP

relay with its low-impedance/ numerical variant so as to

accommodate variation in CT characteristics at their 230 kV

Alamathy SS.

58/II/17 PendingTANTRANSCO

Annexure-III

Page 27 of 34

15-09-2016 at 22:14

hrs

Bus Bar Protection (Zone1) of 230kV Bus-A got operated at

Alamathy Station during fault in 230 kV Alamathy-OPG-1

feeder.


Numerical BBP relay to procured. Timeline: Sep-2019.


Numerical BBP relay to be procured. Timeline: Sep-2019.

Mail received on 10-11-2016 & 20.12.2016:

1. The Bus Bar Protection scheme will be tested for healthiness including the CT circuits.

2. High impedance BBP relay will be replaced by Numerical relay.

Status received vide mails dated 10.01.2017 & 12.04.2017 & 01.06.2017 & 15-06-2017:

1. The Bus Bar Protection scheme was tested for healthiness including the CT circuits. AREVA

make CTs in Alamathy SS are having different kneepoint voltage for the cores. CT cores of

higher knee point voltage has been choosen for BBP in 230kV Korattur, 230kV OPG-1 & 230kV

OPG-2 feeders on 29.11.2016. ---- Completed.

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending,

Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017 & 12-12-2017.

1. ---- Completed

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending


2) TANTRANSCO informed that Numerical BBP would be provided by April, 2018 ---

Pending


1. --- Complied.

2. High impedance BBP relay will be replaced by Numerical relay. Timeline: April-2018.

TANTRANSCO MAIL DATED 22.05.2018 & 08.06.2018 & 23.07.2018:



1. Complied


Multiple tripping at 230 kV

Alamathy Station

1. TANTRANSCO to check the healthiness of BBP relay by

conducting stability test, and take appropriate remedial

action like increasing voltage settings, ensuring the

healthiness of CT’s, using CT’s with similar characteristics

(equal saturation effects & equal winding resistances) etc. at

their 230 kV Alamathy SS.

2. TANTRANSCO to replace the existing high-impedance BBP

relay with its low-impedance/ numerical variant so as to

accommodate variation in CT characteristics at their 230 kV

Alamathy SS.

58/II/17 PendingTANTRANSCO

Annexure-III

Page 28 of 34

64/1/4 Complete outage of North

Chennai TPS STG-1

26-03-2017

at 23:14hrs


running Unit at NCTPS Stg-1

1. TANTRANSCO to take steps to complete insulator

replacement works on the 230 kV lines owned by them in

NCTPS area within 6 months.

2. TANTRANSCO to take steps to implement A/R on all 230

kV lines emanating from NCTPS-I at the earliest.

TANTRANSCO Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017:

1. All the Porcelain insulators were replaced with Polymer insulators in 230kV NCTPS-I -

Tondiarpet feeders - 1 & 2.

---- Completed

2. AR will be implemented on all 230kV lines emanating from NCTPS-I. --- Pending


1. Completed

2. The scheme needs modification to enable AR, since AR was not envisaged for this station

during commissioning. AR will be implemented on all 230kV lines emanating from NCTPS-I

within six months. --- Pending


2) TANTRANSCO informed that A/R would be implemented on all 230 kV lines emanating from

NCTPS-I by June, 2018.


1. Complied.



within six months. Timeline:June-2018.

Pending




Timeline:Sep -2018.


1. Complied.



Timeline:Sep -2018.


AR implemented for 4 feeders and remaining lines will be provided with AR subsequently.


1. Complied

2. AR enabled for 3 feeders.


1. Complied

2. AR enabled for 5 feeders.


2. Enabling AR pending for 3 feeders. ( Sriperumpudhur end breaker problem, Tondiarpet &

Alamathy feeder . static relay to be replaced. Timeline - 1 year


Enabling AR pending for 3 feeders. ( Sriperumpudhur end breaker problem, Tondiarpet &

Alamathy feeder . static relay to be replaced. Timeline -Sep 2019

77/II/9 Multiple trippings at

400 kV Manali Substation

TANTRANSCO to refer the issue of selective tripping of 400

kV side breakers, and non-tripping of 230 kV side breakers

due to operation of Densimeters on low pressure in the

instant case to their OEM, and share OEM’s advice/ remedy

in this regard.

TANTRANSCO mail dated 11.09.2018:

OEM will be referred


TANTRANSCO was asked to update the status.


The issue was referred with OEM & reply awaited

Pending


Thiruvalam Substation

05-10-2018 at 14:32

hrs

Bus-1 got tripped at 230 kV Thiruvalam substation due to

spurious LBB relay (independent) operation of 230kV

Thiruvalam Chittoor line. 230kV Thiruvalam substation was

under single bus operation; hence operation of LBB

protection resulted in tripping of all connected elements

resulting in the complete outage

TANTRANSCO to take steps to implement multi-bus, multi-

zone operation (Double-bus operation) at their 230 kV

Thiruvalam SS by December, 2018.

TANTRANSCO TANTRANSCO MAIL DATED 11-12-2018:

Due to space constraint, the equipments could not be erected.


It was noted that the station was on a single (Main) bus and there was not even transfer bus. In

view of the importance of 230 kV Thiruvalam SS, TANTRANSCO was asked to take steps to

provide dobule-bus operation at their 230 kV Tiruvalam SS.


Feasibility for providing hybrid breaker / shifting of bays will be studied & action will be taken.

Time upto Sep 2019

Pending

Annexure-III

Page 29 of 34

79/II/15 Tripping of 400/ 110 kV ICT-1 &

2 at Rasipalayam

29-09-2018 at 22:57

hrs

ICTs tripped on operation of backup earth fault protection.

Fault was in 110 kV feeder.

TANTRANSCO to revise back-up O/C and E/F protection

settings of 400/ 110 kV ICT’s – 1 & 2 suitably at their

Rasipalayam SS in accordance with Ramakrishna Committee

guidelines

TANTRANSCO TANTRANSCO MAIL DATED 11-12-2018:

Will be revised by Dec 2018.


will be revised by Jan 2019

Pending

80/II/12 Tripping of all elements

connected to 230 kV Anaikadavu

SS

06-11-2018 at 21:35

Hrs

Triggering incident was failure of R-ph PT of 230 kV

Anaikadavu Bus-1. 230 kV Bus bar protection of bus-1

operated resulting in tripping of all the connected elements.

230 kV Anaikadavu was on single bus operation due to failure

of Bus-2 PT during antecedent conditions.

1) TANTRANSCO to adopt recommended OVR, Stage-I and

OVR, Stage-II protections at their 400 kV Anaikadavu and 400

kV Rasipalayam stations, and to ensure that OVR-I_START

signal is configured for triggering corresponding Event Logger

(EL), and OVR-I_TRIP is configured for triggering

corresponding Event Logger (EL) and Disturbance Recorder

(DR).

2) TANTRANSCO to take steps to restore multi-bus, multi-

zone operation at their 230 kV Anaikadavu SS at the earliest.

TANTRANSCO TANTRANSCO MAIL DATED 23.01.2019:

1……Complied

2.Bus PT is to be supplied by the Turnkey contractor will be replaced by 31.03.2019

Pending

Annexure-III

Page 30 of 34

KSEB Mail received vide dated 17.01.2017:

1. 110 kV bus bar protection progressing ----Pending

2. Connection of 220kV earth mat and 110 kV plate earthing system completed.---- Completed

3. Redundancy of 110V DC system in progress. Complete independent redundancy is not

practical for the time being. 48 V DC redundancy was already there. ----Pending

4. Instead of stand alone event logger, SCADA system of 110 kV feeder is expected to be

completed by the end of 2017. SCADA system of 220kV side will be taken up after that ----

Pending

KSEB Mail received vide dated 18.09.2017:Status received vide mail dated 12-12-2017:

1. Detailed engineering of the scheme has been completed. Material procurement is in

progress. ---Pending

2.,3. ---- Completed

4. The SOE and DR are available with time stamping from the numerical relays. Hence stand

alone event logger is not necessary ----- Completed

Status received vide mail dated 11-12-2018:

Work has been already tendered. It is expected that purchase process will completed within

three months.


At the time of bid only one bidder participated and the work has been retendered.

79/I/1 Complete Outage of 220 kV

Idukki Power Station

01-10-2018 at 04:16

hrs

Triggering incident was R-Ph fault in 220kV Idukki-

Kalamassery line-2. R-phase pole of breaker didn’t open at

Idukki end. LBB of Bus-2 operated resulting in tripping of all

connected elements along with running Unit#4 at Idukki and

50MVA station transformer. At the same time, 220kV Idukki

Kalamassery line-1 also got tripped at Idukki end.

Subsequently running Units 1 and 2 also tripped on Governor

oil Low Pressure due to loss of AC supply. This resulted in

complete outage of Idukki PS.

1). KSEBL to check & correct the LBB time setting employed

at their Idukki PH to 200 msec.

2). KSEBL o ensure that DR’s & EL’s of all Protection Relays

(PR’s) at their Idukki PH are configured for recording all

mandated protections & signals.

KSEBL Status received vide mail dated 11-12-2018:

1) Present setting is 180ms.OEM(ABB) suggests that it will give around 200ms delay as it is

having inherent delay is of around 20ms(ie, 180ms +20ms =200ms).With this setting the fault

clearence is found after 220ms.So further revision may be carried out after discussion.

2)Breaker status will be ready only after completing the GOOSE network as part of renovation

of all feeder panels and Idukki first stage units by June 2019 .

Pending

80/II/5 Multiple trippings at 220 kV

Madakathra station

15-10-2018 at 08:57

Hrs

Triggering incident was Y-phase to ground fault in 220kV

Madakathra – Palakkad_KL (Ellapully) line due to flashover of

pilot insulator string. Auto-reclose was successful at

Madakathra end. At the same time bus differential relay Zone-

C mal-operated resulting in tripping of all elements

connected to the bus.

KSEBL to take steps to replace the existing static (high

impedance type) 220 kV BBP with numerical Busbar

protection at their 220 kV Madakathara SS.

KSEBL Status received vide mail dated 11-12-2018:

In progress

Pending

75/II/6Multiple trippings at 400 kV

Raichur-PG SS

03-05-2018

at 18:03 hrs

400 kV RTPS – Raichur PG line-2 tripped due failure of LA in B-

phase at Raichur-PG end. 400 kV RTPS – Raichur PG line-1 &

400 kV Raichur (PG) - Gooty line-1 tripped on operation of

Over-voltage, stage-II protection.

1) PGCIL (SR-I) to set right issues w.r.t. carrier

communication on 400 kV Raichur-PG – RTPS line-2.

2) PGCIL (SR-I) to refer instant trippings to CTU to carry out

Electro Magnetic Transient Phenomena/ Program (EMTP)

analysis, and obtain suitable advice.

3) PGCIL (SR-I) to adopt new OVR-I gradings issue vide SRPC

letter dated 01.05.2018 at their 765/ 400 kV Raichur-PG SS.

PGCIL (SR-I)


1) In 400kV Raichur-RTPS line-1&2 old BPL make PLCC panels were retrofitted with new

PUNCOM make DTPC on 11.08.2018 by availing line S/Ds. presently both channels are

healthy....Completed

2) POWERGRID didn't have EMTP testing provision. Requested CTU to carryout EMTP study. As

discussed, in 75th PCSC Meeting, please advice POSOCO also to carryout EMTP study. ALl DRs in

Comtrade format shared with SRLDC.

3) New OVR gradings issued by SRPC letter dtd 01.05.2018 has been adopted at Raichur SS.....

Completed


2. As informed by PGCIL (SR-I), it was noted that they are yet to receive analysis containing

study results from CTU. In tthis regard, PGCIL (SR-I) was requested to pursue with CTU to get

the job done at the earliest. In case CTU does not have the capability for conducting EMTP

studies, the same may also be informed. --- Pending

Pending

Kerala

23-08-2016

at 11:20 hrs

58/I/1

(GD)

PED


Kalamassery Substation

Triggering incident was conductor snapping in 110 kV

Kalamassery- Kaloor feeder

PGCIL (SR-I) & PGCIL (SR-II)

PendingKSEB to take steps to provide the following at their 220/ 110

kV Kalamassery SS:

1. Busbar protection at 110 kV level

2. Connecting 220 kV and 110 kV sides on to a common

earthmat

3. Redundant DC supply for both protection (220 V) and

communication (48 V) applications

4. Stand-alone Event Logger

1. Time-frame?KSEB

Annexure-III

Page 31 of 34

79/III/3

Tripping of 400 kV Vijayawada –

Nellore-AP line-2

11-09-2018 at 15:26

hrs

B-phase to earth fault occurred in line. At vijayawada end

there was zone-2 trip due to non-receipt of carrier which was

in-turn due to PLCC carrier channel fail. Auto-reclose not

attempted.

PGCIL (SR-I) to take steps to disable sending of DT to the

remote end upon any 3-ph trip (esp. DPR, Z2) operation at

Vijayawada end on 400 kV Vijayawada – Nellore-AP line-2,

and to employ it for a select set of protections such as OV

(Stage-I/ Stage-II), LBB, Reactor backup protections. PGCIL (SR-I)


PGCIL-SR1 The recommended changes will be done in next planned S/D.

Pending

73/III/4 Tripping of 400 kV ILFS-

Nagapattinam PS line-1.

28-03-2018 at 10:32

Hrs

R-phase to earth fault had occurred in line. Auto-reclose

attempt could not be validated with submitted DR of

Nagapattinam end.

PGCIL (SR-II) to furnish a report on the reasons for A/R non-

operation, and the remedial action taken to rectify the same.

PGCIL (SR-II) Review Meeting on 21.12.2018:

PGCIL (SR-II) was asked to furnish the status of implementation of the recommendation at the

earliest.

Pending

74/II/20 Tripping of 400/ 220 kV ICT-2 at

Somanahalli

25-04-2018 at

15:23hrs

ICT-2 got tripped due to mal-operation of Buchholtz’s relay. 1). PGCIL (SR-II) to take steps to replace the faulty PNRV’s of

the ICT’s with the proposed reverse flow blocking devices at

the earliest at their Bidadi, Somanahalli, and Pavagada

stations.

2). PGCIL (SR-II) to configure Event Loggers (EL’s) to capture

events msec level at their Somanahalli SS.



earliest.

Pending

75/II/5 Tripping of 400 kV Kolar –

Tiruvalam line

03-05-2018

at 23:40 hrs

Line tripped on operation of Over-Voltage Stg-1 protection at

Kolar and Direct Trip was received at Tiruvalam. It’s Y-ph

voltage was observed to be 5kV higher when compared to R

& B phase voltages at Kolar.

PGCIL (SR-II) to configure Event Loggers of various protection

relays at their Kolar SS to record events with time stamp that

contains all denominations of time, viz., Hours, Minutes,

Seconds, and Milliseconds.



earliest.

Pending

25-07-2018

at 01:53 hrs

29-07-2018

at 02:02 hrs

80/II/9 Tripping of 400/220 kV ICT-2 at

Bangalore (Somanahalli)

26-10-2018 at 12:10

Hrs

400/220 kV ICT-2 at Bengaluru (Sonamahalli) tripped due to

operation of LV side over flux protection which in turn was

due to suspected 220 kV CVT problem.

PGCIL (SR-II) to configure DR’s & EL’s all protection relays at

their 400/ 220 kV Somanahally SS for all mandated

protections and signals.

PGCIL (SR-II) Yet to be informed Pending

PGCIL (SR-II) Pending77/II/13 Tripping of 400 kV Guttur-

Narendra-PG line-1



earliest.


Guttur. DR & EL not furnished to validate the tripping

PGCIL (SR-II) to check for healthiness of line CVT’s at Guttur

end on 400 kV Guttur – Narendra-PG line-1, and take

appropriate action including their replacement.

Annexure-III

Page 32 of 34

69/I/1 Complete outage of 400kV TPCIL

station

25-10-2017 at 19:33

hrs

400 kV TPCIL-Nellore PS line-1 got tripped from TPCIL end

during fault in 400kV Nellore-Nellore PS line-2. Running units

at TPCIL got tripped due to loss of evacuating line. 400kV

Nellore PG - Nellore PS line-2 and 400kV TPCIL - Nellore PS

line-1 were under shutdown.

TPCIL to configure DEF protection such that it remains in



pickup.

TPCIL Review Meeting on 21.12.2018:

It was noted that no TPCIL representatives had come to attend the meeting

Pending

72/III/5 Tripping of 400 kV HNPCL - K.V.

Kota line

02-02-2018 at 11:46

hrs

Tripped due to R-phase to ground fault. Line did not reclose

at HNPCL.

1. HNPCL to configure DEF protection such that it remains in



pickup.

2. HNPCL to ensure healthiness of A/R scheme implemented

on all 400 kV lines at their station.

HNPCL APTRANSCO maild ated 24.04.2018 & 24.05.2018:

To be attended by HNPCL

HNPCL maild ated 12.05.2018:

1 --- Pending

2.CB close interlock gone to “self-check Fault” state during the AR cycle. Due to that AR gone to

lockout state. Breaker open state CB close interlock should be satisfied condition.Accordingly

the logic has been modiified. ---- Pending


It was noted that no HNPCL representatives had come to attend the meeting

Pending

75/II/2 Tripping of 400kV Hinduja-

K.V.Kota line-2

01-05-2018

at 10:12 hrs

Line-2 tripped on Direct Trip receipt at KV Kota end. At the

same time there was an un-successful auto-reclose attempt

in line-1 due to persistent fault in B-phase.

1) HNPCL to attend PCSC meetings regularly esp. when

tripping events relating to their plant are included in the

Agenda.

2) HNPCL to follow the stipulated File Naming Nomenclature

for naming various tripping files being uploaded in TMS

portal of SRLDC.

3)HNPCL to sort out A/R related issues on 400 kV HNPCL – KV

Kota D/C lines, and put A/R into service from HNPCL end.

4)HNPCL to furnish a detailing tripping report of the event

including remedial measures taken to prevent their

recurrence.

5)HNPCL to configure DR’s & EL’s various protection relays at

the plant to record all mandated protections.

HNPCL Review Meeting on 21.12.2018:

It was noted that no HNPCL representatives had come to attend the the meeting

Pending

B-phase CT failure occurred in 230 kV S.P.Koil - MAPS line-1.

Busbar protection got operated at SP.Koil station. All

elements except 230kV Oragadam and 230kV Kalivandapattu

got tripped at 230kV S.P.Koil station. ‘Y’ phase CT and

support insulators also got damaged.

1.MAPS to furnish a detailed report on the tripping of SP Koil

– MAPS lines 1 & 2 at MAPS end with focus on the

correctness of the settings of Main-I & Main-II relays (for

primary & back-up protections) on both the lines.

2.MAPS to take steps to provide down-loading facility for DR

& EL from Main-I & Main-II relays on all 230 kV lines

emanating from MAPS.

3.MAPS, in co-ordination with SP Koil, to carry out PLCC end-

to-end testing, on SP Koil – MAPS lines 1 & 2, and ensure

healthiness of PLCC communication & carrier-aided

protection.

4.MAPS to put in service Auto-Reclosure feature on all four

230 kV lines emanating from MAPS by June, 2016.

02-04-2016 at 17:08

hrs


S.P.Koil Station of TANTRANSCO

PendingNPCIL (MAPS) Status revided vide MAPS mail dated 06.12.2016;

1. The settings given by M/s TANTRANSCO were adopted for Main –I & Main- II relays for both

the lines. The same settings were verified to be same. Subsequently calibrated was done and

no drift was observed. --- Completed

2. From May 2016 onwards, the DR, EL and trip report are being sent by mail to SRLDC,

Bengaluru by MAPS. --- Completed

3. Monthly maintenance of PLCC equipments is being done by M/s TANTRANSCO. At present

PLCC telephone is not working, it is being followed up. --- Completed

4. CVTs are planned to be procured from M/s TANTRANSCO by the end of February 2017 and

A/R will be implemented for all the lines emanating from MAPS by July-2017 as discussed in the

current SRPC meeting on 25/11/2016. --- Pending

Status received vide MAPS mail dated 06.12.2016 & Review Meeting dated 19.12.2017;

The CVTs procurement is in progress and the scheme (A/R) would be implemented before 31-

03-2018.

Status revided vide MAPS mail dated 11.12.2018

The new CVTs were provided in all the three phases (R & B phases, CVTs were replaced and Y

ph CVT was provided) of Line-1,2 & 4. Replacement of CVTs in line-3 is in progress. Each phase

CVT supply was extended to Main 1 & Main -2 relays. Bus PT supply is extended for Sync.Check.

Time Delayed Auto Reclose (TDAR) scheme with Sync. Check, is being worked out and will be

implemented for the four lines, on by one, before 31-03-2019.

Others

Annexure-III

Page 33 of 34

77/III/1 Tripping of 400 kV CEPL

–Tuticorin PS line-2

02-07-2018 at 16:38

hrs

Line tripped on R-phase to earth fault. Main-CB

(413-52) at Tuticorin PS end auto-reclosed successfully. At

CEPL end, there was Gr - A/B operation resulting in R, Y, & B

phase trip. Direct trip sent observed in DR of Tuticorin PS.

CEPL to furnish a detailed report bringing out the reasons for

A/R non-operation at their end for the subject tripping, and

the remedial measures taken to correct the same to PCSC

forum.

CEPL Review Meeting on 21.12.2018:

When it was informed that they had attended the issue, CEPL was asked to furnish the status of

implementation of the recommendation given at the earliest.

Pending

78/II/2 Tripping of 400 kV Neyveli

TS2Exp -Pugalur line

01-08-2018

at 11:56 hrs

Triggering incident was failure of R-ph tension insulator

string/ flashover in 400 kV Bus-1 at NLC TS2Exp end. Busbar

protection had operated resulting in tripping of all main

breakers connected to 400kV Bus-1 at Neyveli TS2 Exp. In

400kV NLC TS2Exp - Pugalur line, fault was sensed in Zone-1,

R-N at Pugalur end resulting in a single phase trip. Direct Trip

was received at Pugalur end due to operation of over voltage

Stg-2 at NLC TS2Exp.

1. NLCIL to furnish a report along with a suitable SLD on the

tripping event explaining the observed discrepancies [DPR,

Z1 operation, instantaneous operation of OVR-II operation],

and remedial action taken to attend the same.

2. NLCIL to configure DR’s & EL’s of all protection relays at

their NLC TS-IIExp station for all mandated protections &

signals.

NLCIL Review Meeting on 21.12.2018:

NLCIL was asked to furnish the status of implementation of the recommendation given at the

earliest.

Pending

79/II/8 Tripping of 400 kV NLC TS-2

(Exp) – Pugalur line

10-09-2018 at 20:57

hrs

Line tripped on B-N fault. Auto-reclose was not attempted at

Pugalur end due to DT receipt from NLC TS2Exp end. At NLC

TS2Exp end, V>2 trip was observed in DR. Analog voltages

recorded in DR were observed to be less than that required

for O/V Stage-II operation.

NLCIL to furnish a detailed report on tripping event

explaining the observed discrepancies , and proper reasons

for tripping of the line considering both the Main-relays

including remedial action taken w.r.t. healthiness/

replacement of Main protection relays on 400 kV NLC

TS2Exp–Pugalur line.

NLCIL Review Meeting on 21.12.2018:

NLCIL was asked to furnish the status of implementation of the recommendation given at the

earliest.

Pending

80/II/17 Tripping of 400 kV Nellore PS –

SGPL line-1

14-11-2018 at 20:20

hrs

Y- ph to earth fault occurred in line due to snapping of GIS to

Air bushing conductor at SGPL switchyard. The conductor got

grounded such that the fault was being fed by NPS bus and

there was earth fault and broken conductor start at SGPL

end. NPS end got tripped in Zone-2 due to non-receipt of

carrier resulting in a 3-ph trip at NPS. After 500ms, earth fault

occurred at SGPL end resulting in Zone-1 operation and 3

phase trip. A/R was not attempted at SGPL end

SGPL to examine the reasons for no-operation / failure of

Auto-reclosure from their end for the subject tripping, and

furnish an action taken report detailing remedial measures

taken to PCSC forum.

SGPL Yet to be informed Pending

80/III/6 Tripping of 400 kV Neyvelli TS2

(Exp) - Pugalur line

07-11-2018 at 05:50

Hrs

400 kV Neyvelli TS2Exp - Pugalur tripped on

B-phase to ground fault due to DPR, Z1 operation. Auto-

reclose was successful at Pugalur end and the line tripped at

Neyveli TS2Exp end only. Auto-reclose was not attempted at

Neyveli TS-2(Exp) end

NLCIL to furnish a detailed report on the reasons for A/R non-

operation for the subject tripping at their NLCTS2Exp station

including remedial measures taken to PCSC forum.

NLCIL Yet to be informed Pending

Annexure-III

Page 34 of 34

Sl.No. Element Name Outage date/time Revival date/time Reason for outage Sender/ Receiver Remedial Measures/ Actions taken

1 400KV-GUTTUR-HIRIYUR-2 24-10-2018/08:15:00 24-10-2018/14:27:00 Tripped due to fire in line reactor KPTCL/ PGCIL(SR-II)

KPTCL:

Failure of line reactor which cattched

fire at Guttur end resulted in tripping

of line. Direct trip was received at

Hiryur. operation of protection

system is in order.

PGCIL (SR-II):

2 400KV-DONI-GUTTUR-1 20-11-2018/10:24:00 20-11-2018/11:45:00 DC FAIL KPTCL

PGCIL (SR-I):

Both ends belongs to KPTCL.

KPTCL:

3 400KV-DONI-MUNIRABAD 20-11-2018/10:24:00 20-11-2018/10:45:00 DC FAIL PGCIL (SR-I)

PGCIL (SR-I):

Line tripped at Dhoni end only due to

DC supply issue at Dhoni. Line was

holding from Munirabad.

APTRANSCO: Line does not belong to

APTRANSCO.

4 220KV-THENI-MOOZIYAR-1 07-12-2018/11:57:00 07-12-2018/12:18:00 RELAY MALOPERATION TANTRANSCO/ KSEBL

TANTRANSCO : Passing fault

KSEBL: Tripped and reclosed at

moozhiyar end.Z#1, Y ph to earth. 65

km

5 220KV-THENI-MOOZIYAR-1 09-12-2018/13:27:00 09-12-2018/13:48:00 LINE TO GROUND FAULT TANTRANSCO/ KSEBL


KSEBL: Reclosed and tripped at

moozhiyar end. Z#1, Y ph to earth. 85

km

6 220KV-AMBEWADI-XELDEM 11-12-2018/11:30:00 11-12-2018/12:12:00 C-N fault KPTCL/ GED To-be-discussed

7 220KV-AMBEWADI-XELDEM 22-12-2018/02:19:00 22-12-2018/03:00:00 DISTANCE PROTECTION KPTCL/ GOA To-be-discussed

8 220KV-AMBEWADI-PONDA-2 24-12-2018/22:07:00 DISTANCE PROTECTION KPTCL/ GOA To-be-discussed

9 220KV-SEDAM-TANDUR-1 28-12-2018/10:52:00 28-12-2018/12:20:00 TO ATTEND HOTSPOT KPTCL/ TSTRANSCO

TSTRANSCO:

LC was availed by KPTCL.

KPTCL:

10 220KV-THENI-MOOZIYAR-1 04-01-2019/12:26:00 04-01-2019/15:12:00 TRIPPED ON Y-N FAULT TNEB/ KSEB


KSEBL: Phase to phase tripping, no

reclosing

11 400KV-KARAIKUDI-KAYATHAR-2 04-01-2019/18:31:00 DT RECEIVED AT KARAIKUDI END PGCIL (SR-II)/ TANTRANSCO

TANTRANSCO:

DC Earth leakage is being isolated.

PGCIL (SR-II):

12 400KV/220KV TALARCHEVU-ICT-2 09-01-2019/12:22:00DIFFERENTIAL PROTECTION

ACTEDAPTRANSCO To-be-discussed

13 400KV-HOSUR-SALEM-2 10-01-2019/17:34:00 11-01-2019/00:03:00 TRIPPED ON Y-N FAULT PGCIL (SR-II) To-be-discussed

Pending Remedial Measures/ Actions taken for the Critical Tripping Incidents (as on 13.02.2019)

Annexure-IV

Page 1 of 3

14 400KV-PALAVADI-RASIPALYAM-1 11-01-2019/15:53:00TRIPPED ON RELAY MAL

OPERATIONTANTRANSCO

TANTRANSCO:

Faulty VT Module was replaced by

new one at Palavady end.

15 220KV-AMBEWADI-PONDA-2 13-01-2019/11:36:00 Tripped on Y-B Fault KPTCL/ GED To-be-discussed

16 400KV-HINDUJA-KV_KOTA-1 14-01-2019/13:46:00 TRIPPED ON B PHASE FAULT HNPCL/ APTRANSCO To-be-discussed

17 400KV-KHAMMAM-WARANGAL-1 14-01-2019/14:37:00 14-01-2019/14:56:00 TRIPPED DUE TO B-N LINE FAULT PGCIL (SR-I) To-be-discussed

18 400KV-GOOTY-RAICHUR_PG-2 16-01-2019/00:40:00 TRIPPED DUE TO B-N LINE FAULT PGCIL (SR-I) To-be-discussed

19 400KV-GOOTY-RAICHUR_PG-2 16-01-2019/12:21:00 Y-N FAULT PGCIL (SR-I) To-be-discussed

20 220KV-KADAKOLA-KANIYAMPETTA 17-01-2019/16:44:00 17-01-2019/18:27:00TRIPPED ON B-PHASE DISTANCE

PROTECTIONKPTCL/ KSEB

KSEB end: Main 1 and Main 2 relay

tripped in Zone: 1 , CG fault. Reclosed

and Lock out. 2ARKN idle charged at

the time of fault. No issues in 2KDKN

feeder in KSEB area. May be transient

fault.

KPTCL:

21 400KV-SINGARENI-SUNDILA-2 17-01-2019/19:22:00 MASTER TRIP RELAY ACTED TSGENCO/ TSTRANSCO

TSTRANSCO:

Line is under open condition at

Sundilla end. Over Voltage Stage-1

operated at Sundilla end and DT was

sent to Singareni end.

TSGENCO:

22 400KV-SRIPERUMBADUR-THIRUVALAM-1 20-01-2019/01:58:00 20-01-2019/03:28:00 B phase light arrester flashover PGCIL (SR-II) To-be-discussed

23 400KV-HINDUJA-KV_KOTA-2 20-01-2019/13:10:00 TRIPPED ON R-Y FAULT HNPCL/ APTRANSCO To-be-discussed

24 765KV-CUDDAPAH-THIRUVALAM-2 20-01-2019/08:54:00 20-01-2019/09:12:00 DT RECEIVED PGCIL (SR-I)/ PGCIL (SR-II) To-be-discussed

25 400KV-DONI-MUNIRABAD 22-01-2019/15:44:00 22-01-2019/17:39:00 TRIPPED ON Y-N FAULT KPTCL/ PGCIL (SR-I) To-be-discussed

26 220KV-SEDAM-TANDUR-1 25-01-2019/15:48:00 25-01-2019/19:10:00 TRIPPED ON R-N FAULT KPTCL/ TSTRANSCO To-be-discussed

27 400KV-SURYAPET-KV_KOTA-2 26-01-2019/10:26:00 TRIPPED DUE TO B-N LINE FAULT TSTRANSCO/ APTRANSCO To-be-discussed

28 220KV-SEDAM-TANDUR-1 26-01-2019/10:12:00 26-01-2019/12:09:00 R-N FAULT KPTCL/ TSTRANSCO To-be-discussed

29 400KV-NELAMANGALA-HASSAN-1 27-01-2019/14:44:00 TRIPPED ON B-N FAULT KPTCL/ PGCIL (SR-II) To-be-discussed

30 400KV/220KV KHAMMAM-ICT-1 27-01-2019/14:33:00 27-01-2019/15:42:00Directional over current

protection operatedPGCIL (SR-I) To-be-discussed

31 HVDC 500KV GAZUWAKA Pole 28-01-2019/11:12:00 28-01-2019/14:15:00 Thyristor redundancy failure PGCIL (SR-I) To-be-discussed

32400KV-CUDDAPAH-NAGARJUNASAGAR_PG-1

400KV AC LINE29-01-2019/06:14:00 29-01-2019/08:11:00 TRIPPED ON BUCCHOLZ NGR. PGCIL (SR-I) To-be-discussed

33 400KV-SURYAPET-JULURUPADU-2 30-01-2019/13:28:00 30-01-2019/15:13:00 RELAY MALOPERATION TSTRANSCO To-be-discussed

34 400KV-HINDUPUR-NP_KUNTA-1 31-01-2019/09:33:00 TRIPPED DUE TO R-N FAULT APTRANSCO/ PGCIL (SR-I) To-be-discussed

35 400KV-SURYAPET-JULURUPADU-2 31-01-2019/14:17:00 R-N FAULT TSTRANSCO To-be-discussed

36 400KV-NELAMANGALA-TALGUPPA-1 01-02-2019/16:56:00 01-02-2019/20:34:00 DISTANCE PROTECTION KPTCL To-be-discussed

37 400KV/220KV HOODY-ICT-1 03-02-2019/22:25:00 04-02-2019/00:29:00 AIR PRESSURE LOW KPTCL To-be-discussed

38 220KV-KAIGA-KADRA-1 04-02-2019/20:19:00 04-02-2019/20:51:00 BUS BAR PROTECTION OPERATED NPCIL (KGS)/ KPCL To-be-discussed

39 400KV-KALPAKKA-KHAMMAM-1 04-02-2019/13:15:00 Tripped on R-B-N fault APTRANSCO/ PGCIL (SR-I) To-be-discussed

40 400KV-KTPS_VII-KHAMMAM-1 04-02-2019/06:15:00 04-02-2019/06:27:00 MAL-OPERATION TSGENCO/ PGCIL (SR-I) To-be-discussed

41 400KV-CUDDAPAH-NP_KUNTA-1 05-02-2019/16:21:00 05-02-2019/17:07:00 MAL-OPERATION PGCIL (SR-I) To-be-discussed

42 400KV-HINDUJA-KV_KOTA-1 06-02-2019/11:08:00 06-02-2019/12:29:00 TRIPPED ON Y-N FAULT HNPCL/ APTRANSCO To-be-discussed

43 400KV-CUDDAPAH-NP_KUNTA-2 06-02-2019/09:50:00 to limit line loading PGCIL (SR-I) To-be-discussed

44 400KV-KAIGA-GUTTUR-1 07-02-2019/11:48:00 DISTANCE PROTECTION NPCIL (KGS)/ KPTCL To-be-discussed

Annexure-IV

Page 2 of 3

45 400KV-KAIGA-GUTTUR-2 07-02-2019/11:48:00 DISTANCE PROTECTION NPCIL (KGS)/ KPTCL To-be-discussed

46 HVDC 500KV KOLAR_DC Pole 07-02-2019/15:15:00 07-02-2019/16:10:00Due to agricultural fire / brick kiln

fire near kolarPGCIL (SR-II) To-be-discussed

47 220KV-SULURPET-GUMMIDIPOONDI-1 08-02-2019/13:52:00 08-02-2019/14:46:00 TRIPPED ON R-N FAULT APTRANSCO/ TANTRANSCO To-be-discussed

48 400KV-ALAMATHY-MANALI-1 08-02-2019/16:40:00 Tripped on Y-B Fault TANTRANSCO To-be-discussed

49 400KV-GHANAPUR-RAMAGUNDAM-4 09-02-2019/23:28:00 Tripped on R-B Fault PGCIL (SR-I)/ NTPC To-be-discussed

50 400KV-SURYAPET-KV_KOTA-2 10-02-2019/19:08:00R Phase distance protection

operatedTSTRANSCO/ APTRANSCO To-be-discussed

51 400KV-VTPS_IV-SURYAPET-1 10-02-2019/13:20:00 10-02-2019/15:44:00 Tripped on R-B-N fault APGENCO/TSTRANSCO To-be-discussed

52 400KV/220KV SUNDILA-ICT-1 10-02-2019/12:20:00 10-02-2019/16:44:00Tripped due to switching

operation @ 220kv sideTSTRANSCO To-be-discussed

53 400KV/220KV KAIGA-ICT-2 11-02-2019/11:46:00 11-02-2019/13:08:00 TRIPPED ON LBB OPERATION NPCIL (KGS) To-be-discussed

54 400KV-NELAMANGALA-HASSAN-1 11-02-2019/00:05:00 TRIPPED ON R-N FAULT KPTCL/ PGCIL (SR-II) To-be-discussed

55 400KV-KAIGA-GUTTUR-2 11-02-2019/11:46:00TRIPPED ON DISTANCE

PROTECTIONNPCIL (KGS)/ KPTCL To-be-discussed

Annexure-IV

Page 3 of 3

System Study for Review of SPS for Contingency of 400kV/220kV ICTs at Kaiga GS

Since the objective was to determine the quantum of the generation to be backed down at 220kV

Kadra and 220kV Kodasalli Generating Plants during non-availability of one of the ICTs at Kaiga and

220kV Naghjeri Kodasalli line -1 & 2 kept under idle charged conditions, various scenarios as

illustrated below had been considered, and corresponding system studies were presented:

Building of BaseCase (Case 0):

Nov’18 Peak PSSE base case with following conditions:

(1) Generation Details

Sno. Plant

Total Gen

(Installed MW)

Total Gen at LV side

(MW)

Total Generation at HV side

(MW)

U#1 GT LV

Side

U#1 GT HV

side

U#2 GT LV

Side

U#2 GT HV

side

U#3 GT LV

Side

U#3 GT HV

side

U#4 GT LV

Side

U#4 GT HV

side

1 Kadra 150 128 124 49 48 48 47 31 30 - -

2 Kodasalli 120 117 113 38 37 39 38 40 39 - -

3 Kaiga 880 842 783 202 188 200 186 210 195 230 214

(2) Load Details

Sno. Load Station Total Load (MW)

1 Karwar 70

(3) List of 220kV lines and 400kV/220kV ICTs under outage

Sno. Line Remarks

1 220kV Kadra Karwar line-1

2 220kV Kodasalli Naghjeri

line-1 and 2 Idle charged

3 400kV/220kV Kaiga ICT#1 Tripped at 16:04hrs on 13-11-2018

Annexure-V

Page 1 of 5

Case 0: case as on 13-11-2018 at 16:55hrs (From SCADA Snapshot)

Sno. Transmission Element

MW

SCADA PSSE

1 400kV/220kV Kaiga ICT#2 543 542

2 220kV Kaiga Kadra 64 73

3 220kV Kaiga Kodasalli 89 95

Matching of SCADA and PSSE results for Case 0.

1. Case 1:

Case 0 condition with full generation at Kaiga, Kodasalli and Kadra:

In the base case when generation is full at Kaiga, Kodasalli and Kadra, flow in 400kV/220kV

Kaiga ICT#2 increased to 600MW.

Case1: Case 0 condition with full generation at Kaiga, Kodasalli and Kadra

2. Case 2:

Case 0 condition with 100% generation at Kaiga, 90% generation at Kodasalli and Kadra:

In the base case when generation is full at Kaiga and 90% at Kodasalli and Kadra, flow in

400kV/220kV Kaiga ICT#2 increased to 575MW.

Case2: Case 0 condition with full generation at Kaiga, 90% generation at Kodasalli and Kadra

Annexure-V

Page 2 of 5

3. Case 3:



400kV/220kV Kaiga ICT#2 increased to 550 MW.


4. Case 4:





Annexure-V

Page 3 of 5

5. Case 5 :





6. Case 6 :




Case 6: Case 0 condition with full generation at Kaiga, 50% generation at Kodasalli and Kadra

Annexure-V

Page 4 of 5

Summary :

400kV/220kV Kaiga ICT#1 under outage

220kV Kodasalli Naghjeri line-1 and 2 not in service

Karwar load is 70MW

All Kaiga generating units are in service with full capacity

Case Transmission

Element

MW Kaiga Kadra Kodasalli Kadra and

Kodasalli

SCADA PSSE Total MW

Total MW

Total MW

Total MW

Case-0 Generation as on 13-11-2018 at 16:55hrs

400kV/220kV Kaiga ICT#2

543 542 783 124 113 237

Case-1

Full Generation at Kodasalli and Kadra


-

600 818 147 117 264

Case-2

90% Generation at Kodasalli and Kadra


-

575 818 132.3 105.3 237.6

Case-3



-

550 818 117.6 93.6 211.2

Case-4

70% Geenration at Kodasalli and Kadra


-

526 818 102.9 81.9 184.8

Case-5



-

501 818 88.2 70.2 158.4

Case-6



-

477 818 73.5 58.5 132

*****

Annexure-V

Page 5 of 5

Sl. No. Bay name/Bus Voltage Protection/Element/

Equipment/ System

auditated

Remarks/Deficiences/Nonconformity observed Status of Implementation of Protection Audit Recommendations Remarks Latest Status (To be filled in by the

Constituent)

1 Control and

Protection Panels

For 400 KV Busbar protection, one number of main Bus bar protection scheme is available

for each bus; Check Zone protection is available as inbuilt feature to main relay (Distributed

system).Commissioning of new busbar protection panels with nemerical relay is under

progress.


New Busbar protection panels with numerical relay commissioned on 17.12.2016.

Complied

2 On 220 kV side, Only Single Bus bar protection scheme is available (ABB RADSS) for each of

the two buses . No redundant main 2 or Check zone protection available. CT supervision

relays are not provided. Redundant Bus bar protection or Check zone shall be considerd.


New 220KV Busbar protection panel will be commissioned by May 2018.


New 220KV Busbar protection panel will be commissioned by December 2018.


Procurement action to be initiated for New 220KV Busbar protection panel.

Pending

3 Auto-reclose feature is not enabled for 220kV lines. Mail dated 14.02.2018:

Completed. Auto-reclosure feature enabled for all 220KV lines.

Complied

4 Over current protection has been kept enabled on alll 400 kV feeders. Mail dated 14.02.2018 & 23.07.2018:

Normal Over current function is not enabled in MICOM P444 relay. Over current

function with SOTF is enabled. During dead line charging condition it acts as SOTF

function and remaining time it acts as definite time over current function. However

considerable time delay 3 seconds and 200% pick up is adopted.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. Since O/C

protection is undesirable in 400 kV lines, APTRANSCO was asked to take

steps to disable the same.

The issue was discussed in PCSCM-81 held on 24.01.2019. Since O/C

protection is undesirable in 400 kV lines, APTRANSCO was asked to take

steps to disable the same.

Pending

5 For all 220 kV feeders [except S.Palli-1 Main-2 feeder (ABBREL670)] all relays are of static

relays.


All the static relays were replaced with numerical relays during retrofitting works.

Completed for all 220KV feeders.

Complied

6 400kV Ghanapur line Main -1 is of POTT (SEL 421) scheme and Main-2 is of PUTT scheme. Mail dated 14.02.2018:

Main-1 SEL 421 relay which was with POTT was replaced with 7SA522 with PUTT

during retrofitting works. 400KV Ghanapur (now Maheswaram) line Main-1 and Main-2

kept in PUTT scheme.

Complied

7 Relay Setting Pole discrepency relay time :

- 2.5s for 400kV Power grid transmission line main and tie breakers.

- 1.25s for 400kV AP TRANSCO (Srisailam) transmission line main and 1.5s for tie breakers.

- 0.5s for 220kV transmission lines.

- 0.5s for ICT-1 and Bus Reactor.

- 2.5s for ICT-2.


Pole discrepancy relay time provided as per standard. (Line main breaker:1.5s, Tie

breaker:2.5s, Transformer and Reactor breakers:0.5s) And for all 220KV transmission

lines 1.5s provided.

Complied

Status of Implementation of New Protection Audit Recommendations (as on 28.01.2019)

APTRANSCO

1) 400/ 220 kV Narnoor SS [16–18 February, 2016]

1/95

Annexure-VI

Page 1 of 95

8 PSB was kept blocked for all zones with unblock time delay of 2 sec on 400 kV Srisailam

feeder. For all 400 kV PGCIL feeders, PSB was kept blocked for all zones except zone-1 with

unblock time delay of 2 sec.

Mail dated 14.02.2018 & 23.07.2018::

APTRANSCO views on power swing protection philosophy communicated to SRPC vide

Lr.No.CPS/SP/121/SRPC/D.No.510/15, Dt.14.12.2015. As per setting provided.

The issue was discussed in PCSC-76 meeting held on 26.07.2018.

APTRANSCO was asked to keep PSB blocked for all Zones except Zone-1

with unblock time delay of 2 sec on 400 kV Srisailam feeder.

The issue was discussed in PCSCM-81 meeting held on 24.01.2019.


with unblock time delay of 2 sec on all 400 kV feeders.

Pending

9 400kV Stub protection current set and time delay set as I> 150% and 100ms against the

recommendeed setting of I>250% and time delay of 50ms by M/S Tractebel. APTRANSCO

to take action as appropriate.

Mail dated 14.02.2018 & 23.07.2018::

As per APTRANSCO practise Stub protection pick up current setting 200% and time

delay 0 ms is adopted.


APTRANSCO was asked to adopt the recommended settings of I>250 % and

time delay of 50 ms for 400 kV Stub Protection.




Pending

10 Zone resistive reach setting & time setting for all 400kV and 220kV distance protection are

found to be different from the recommanded setting given by Tractebel based on

Ramakrishna committee recommendations (Task force committee guidelines). APTRANSCO

to take action as appropriate.


The existing resistive reach settings are found to be OK for distance protection

resistive reaches.

Complied

11 DEF is enabled in main-1 and disabled in main-2 distance relay in 400kV srisailam line . Due

to this, DEF will not be available in the event of outage of Main-1 distance relay. DEFR timing

on 400 kV feeders was found to be kept at different settings (308 msec, 470 msec.)


DEF is enabled in Main-1 and Main-2 distance relay in 400KV Srisailam line. (New

relays for Main-2 provided with 7SA522.)

Complied

12 SOTF funtion disabled in all 220 kV feeders except Somayajulapalli line-1 (main-2) and

Brahmanakotkur line (Main-1 & 2).


SOTF function enabled for all 220KV feeders.

Complied

13 The distance protection for all 200 kV feeders was configured for three (forward) zones only.

There was no reverse-zone available for the distance protection provided on 220 kV feeders.

In 220kV B. Kotkur feeder, distance protection was configured with 5 zones (forward - Zone -

1 to 4); however, zone-5 was kept off.


The distance protection for all 220KV feeders configured for four (forward) and one

(reverse) zone.

Complied

14 Over current and directional earth fault protections are not provided on any of the 220kV

lines.


In old realys these functions are not available.Over current and directional earth fault

protections provided for all 220KV lines during retrofitting works (Numerical relays).

Complied

15 High set unit was not provided for over flux protection of ICT’s. Mail dated 14.02.2018:

Inverse charactaristic is selected for over flux protection.

Complied

16 GPS is not available. Mail dated 14.02.2018:

GPS provided.

Complied

17 Stand alone DR with automatic downlaoding facility to centralized PC is not availble. Stand-

alone EL though available, is not in working condition. APTRANSCO informed that manual

downloading from relay specific DR's and EL's is being done as and when fault occurred for

400kV lines.


Centralised EWS is provided for downloading EL and DR automatically.

Complied

18 DR is not available for 400kV/220kV bus bar protection and for all 220kV lines . Mail dated 14.02.2018:

1. Completed for 400KV Busbar protection DR can be download.

2. Completed for 220KV lines DR can be downloaded.

3. Pending for 220KV Busbar protection panel; will be commissioned by May 2018.


3.220KV Busbar protection panel will be commissioned by December 2018.--- Pending


Procurement action to be initiated for 220KV Busbar protection panel.

Pending

2/95

Annexure-VI

Page 2 of 95

19 AC Distribution Auto Changeover is not available in ACDB for 415V Auxiliary supply 1 & 2 and DG set. Auto

Main FAilure (AMF) panel in DG set is not in service. Supply Change over operation is carried

out manually.

Mail dated 14.02.2018 & 23.07.2018:

Auto changeover operation is not possible in ACDB for 415V Auxilary supply 1&2 and

DG set as with the existing older version of LT AC scheme, where the necessary

protection scheme for changeover operation is not available and hence the supply

change over operation is being carried out manually.


APTRANSCO was asked to take steps to provide auto supply-changever

among auxiliary supplies - AC-1 & AC-2 & DG.


APTRANSCO was asked to take steps to provide auto supply-changever

among auxiliary supplies - AC-1 & AC-2 & DG.

Pending

20 For ACDB, there is only one AC source from 33kV/11kV Narnoor SS; however, the same is

being fed to various switchyard auxiliaries through two parallel transformers.


It was requested the APSPDCL authorities for the alternate 11KV supply source and the

same will be completed by May 2018.


Completed. Alternate 11KV supply source was arranged by APSPDCL authorities on

02.06.2018.

Complied

21 DC Distribution For 220kV and 400kV bus bar protection panel, 2 DC sources are available with selector

switch only. Automatic changeover is not provided.


Completed:-For 400KV busbar protection panel (new panel commissioned), 2 DC

sources are available and automatic changeover provided.

Pending:- 220KV Busbar protection panels will be commissioned by May 2018.


Completed:-For 400KV busbar protection panel (new panel commissioned), 2 DC

sources are available and automatic changeover provided.

Pending:- 220KV Busbar protection panels will be commissioned by December 2018.


Pending:- Procurement action to be initiated for 220KV Busbar protection panels .

Pending

22 Communication

system

In Communication panels (except Ghanapur, Gooty and AP Carbides 1 & 2 feeders as per

shceme), each panel has been supplied with dual DC source.


There is no provision of dual DC source for PLCC equipments.

Complied

23 The communication with the only numerical relay (ABB REL670) available on S.Palli line-1

(Main-2) feeder, was found to be unhealthy.


The communication with the only numerical relay (ABB REL670) available on S.Palli

line-1 (Main-2) feeder is rectified and found healthy. Main-1 also provided with

numerical relay.

Complied

24 Walkie-talkie system for communicating with Control room personnel is not provided. Mail dated 14.02.2018:

Walkie takie will be provided by May 2018.


Walkie takie will be provided by October 2018.


Note under circulation for initiation of Walkie takie Procurement action

Pending

25 400kV/

220kV

Switchyard Field

Equipments

Even though the designed 220 kV busbar arrangement has bus-1 & bus-2 & transfer bus, the

transfer bus was kept out of service, and the transfer bus coupler is being used as line-CB.

With this arrangement, breaker maintenance cannot be undertaken without availing line

shutdown

Mail dated 14.02.2018 & 23.07.2018::

The rectification/modification works will be attended in the due course duly entrusting

the works either in the existing contacts ( if any) or in forth coming tenders/orders.


The rectification/modification works will be attended in the due course duly entrusting

the works either in the existing contacts ( if any) or in forth coming tenders/orders.

Pending

26 Lightning protection (LA's) Earthing is not done as per standards/ NFPA in the most of 220kV

and 400kV bays. LA's (system) earthing is connected to earth electrodes directly as well as

through equipment earthing.


Attended & Rectified as per the directions given by the protection audit team by

isolating the surge counters from the erected structures of 220KV and 400KV

lightening arrestors with insulating media.

Complied

27 400kV Bus reactor has not been equipped with cooling fans. Mail dated 14.02.2018:

Attended & Rectified by arranging cooling fans to 63MVAR 400KV Bus reactor.

Complied

3/95

Annexure-VI

Page 3 of 95

28 Door earthing not done for some of marshalling boxes iin 400kV and 220kV bays; PVC

conduits for cable entries to the marshalling boxes found to be kept unsealed in some of the

400kV and 220kV bays.


Attended & Rectified by arranging door earthing to all the marshalling boxes in the

400KV and 220KV bays as well as seal the PVC conduits to the marshalling boxes.

Complied

29 220 V Battery Units and Battery chargers were housed in the same room along with other

relay panels. 48 V Battery Units and Battery chargers were housed in the same room along

with other PLCC panels

Mail dated 14.02.2018 & 23.07.2018:

The 220V Battery units and Battery chargers were housed in the same room along

with other relay panels and 48V Battery units and Battery chargers were housed in the

same room along with other PLCC panels at the time of commissioning of the Sub-

station by the Construction wing as per the approved plan & design.


APTRANSCO was asked to take steps to provide suitable partitions between

(i) 220 V Battery Units & Batter Chargers and other relay panels; (ii) 48 V

Battery Units & Batter Chargers and other PLCC panels.


APTRANSCO was asked to take steps to provide suitable partitions between

(i) 220 V Battery Units & Batter Chargers and other relay panels; (ii) 48 V

Battery Units & Batter Chargers and other PLCC panels.

Pending

30 General It is observed that the existing test-kits are of obsolete models and not in working condition.

The following test kits shall be generally required for proper maintenance of 400 kV Narnoor

SS:

1. Digital Earth resistance Tester

2. 12 kV Capacitance and Tan Delta Kit

3. Digital Multi Meter Model:287

4. Digital Low Range Tong Tester

5. Energey Meter Testing Kit

6. Dynamic Contact Resistance Measurement Test Kit

7. Transformer Winding Resistance Measurement Test Kit

8. Transformer Turns Ratio Kit

9. Insulation Resistance test-kit with induction compensator


Items Nos 2 & 7 are provided. The remaining kits will be arranged by July 2018.


Items Nos 2 & 7 are provided. The remaining kits will be arranged by October 2018.


Items Nos 2 & 7 are provided.Procurement action to be initiated for the remaining kits.

Pending

31 It is observed that no Laptop with latest features for downloading the disturbance data and

relay settings is available.


Received laptop during retrofitting works.

Complied

Sl. No. Status of Implementation of Protection Audit Recommendations Remarks Latest Status (To be filled in by the

Constituent)

1 Mail dated 03.08.2018:

Submitted

Complied

2 Mail dated 03.08.2018:

As per the Ramakrishna Committee guidelines, the existing distance protection timings

for Zone-2, Zone-3, Zone-4 and Zone-5 (reverse) are reviewed and the following

timings are revised and adopted for 400kV lines.

Existing:- Revised:-

Zone-1 0.00 Sec Zone-1 0.00 Sec



Zone-4 1.50 Sec Zone-4 1.00 -1.20 Sec

Zone-5 (R) 0.50 Sec Zone-5 (R) 0.50 Sec

Complied

2) 400/ 220 kV Uravakonda SS [5–6 April, 2018]

Deficiences/Nonconformity observed

Protection Philosophy being followed by APTRANSCO for various transmission elements (Lines/ ICT's/ Reactors/ Busbar/ etc.) shall be furnished.

In 400 kV lines, distance protection timings for Zone-2, Zone-3, Zone-4 and Zone-5 (reverse) shall be reviewed in line with Ramakrishna Committee

guidelines.

4/95

Annexure-VI

Page 4 of 95

3 Mail dated 03.08.2018:

The existing power swing philosophy (with all zones blocked for unblocked time delay)

for 220kV & 400kV transmission lines will be continued, however as per

recommendation of SRPC the system studies will be carried out using protection suit

software during PMS project implementation by PRDC.


The existing power swing philosophy (with all zones blocked for unblocked time delay)

for 220kV & 400kV transmission lines will be continued, however as per

recommendation of SRPC the system studies will be carried out using protection suit

software during PMS project implementation by PRDC.



with unblock time delay of 2 sec on all 220 kV & 400 kV feeders.

Pending

4 Mail dated 03.08.2018:

As per the SRPC recommendations, (Minutes of 22nd PCSC) line differential protection

is provided for line length less than 3km, in respect of 220KV lines. The same will be

continued as per minutes of 59th PCSC.


As per the SRPC recommendations, (Minutes of 22nd PCSC) line differential protection

is provided for line length less than 3km, in respect of 220KV lines. The same will be

continued as per minutes of 59th PCSC.

Pending

5 Mail dated 03.08.2018:

400KV Jammalamadugu Line-1 checked ok and remaining feeders will be checked on

availability of line clear.


Completed

Complied

6 Mail dated 03.08.2018:

The following settings are adopted for pole discrepancy time delay i.e

(i) For all line Main-CB’s and Tie-CB’s where Auto-Reclosure with priority has been

employed with dead-times of 1 Sec & 2 Sec respectively, PDR time delay is kept as 1.5

Sec and 2.5 Sec respectively.

(ii) For all other elements, PDR time delay is kept as 0.5 Sec.

Complied

7 Mail dated 03.08.2018:

Currently for the 400/220kV ICT’s, high-set operation is provided to cover 70-80% of

transformer winding, (not exceeding 80%) with time delay of 0 mSec. With the

existing setting there is no mal operation of High set element observed so far. Hence,

the existing philosophy will be continued.


Currently for the 400/220kV ICT’s, high-set operation is provided to cover 70-80% of

transformer winding, (not exceeding 80%) with time delay of 0 mSec. With the

existing setting there is no mal operation of High set element observed so far. Hence,

the existing philosophy will be continued.




Pending

8 Mail dated 03.08.2018:

O/C high set provided on 220KV side (LV side) also, on 18.07.2018. over current

IDMT protection also available on LV side.

Complied

9 Mail dated 03.08.2018 & 17.01.2019:

Presently wired as per approved scheme drawings only.


APTRANSCO was asked to comply with the recommendation at the earliest.

Pending

10 Mail dated 03.08.2018:

As per the SRPC recommendations, re-trip time delay 100 mSec is adopted in LBB

protection of all circuit breakers on 18.07.2018.

Complied

The existing Power Swing Philosophy (with all Zones blocked for unblocked time delay) for 220 kV & 400 kV transmission lines to be reviewed to

adopt either of the following two approaches:

(i) Zone-1 --> Trip; Highers Zones --> Block for a delay of unblocking time delay (2 sec) & then Trip.

(ii) Block all Zones with Out-of-Step tripping enabled at electrical zero locations by carrying out required system studies.

In view of the short length of the 220 Amidyala lines 1 & 2 (9. 45 km), Line Differential Protection may be provided in place of the existing distance

protection.

Auto-Reclosure feature provided on 400 kV & 220 kV lines may be got checked for correctness of functionality & healthiness of the logic employed.

It is observed that Pole Discrepancy time delay has not been set uniformly. It is recommended to keep PDR gtime delays as follows:

(i) For all line Main-CB's and Tie-CB's where Aut-Reclosure with priority has been employed with dead-times of 1 sec & 2 se respectively, PDR time

delay shall be kept as 1.5 sec and 2.5 sec respectively.

(ii) For all other elements, PDR time delay shall be kept as the minimum avaiable in the relay, but not less than 100 msec. This may be preferably

kept as 0.5 sec.

For the 400/ 220 kV ICT's, O/C & E/F protections high-set operation may be provided with time delay of 50 msec.

O/C Protection (high-set & IDMT) may be provided on 220 kV sides of the 400/ 220 kV ICT's.

Group-A Protections and Group-B Protections for 400/ 220 kV ICT's shall be arranged to be fed from different DC Supplies.

Re-Trip feature time delay for the circuit breakers shall be revised from the existing 200 msec to 100 msec.

5/95

Annexure-VI

Page 5 of 95

11 Mail dated 03.08.2018 & 17.01.2019:

During the Statutory Inspection remarks this point is cleared.

The issue was discussed in PCSCM-81 meeting held on 24.01.2019. APTRANSCO was

asked to comply with the recommednation at the earliest.

Pending

12 Mail dated 03.08.2018 & 17.01.2019:

Measured and recorded frequently.

Complied

13 Mail dated 03.08.2018 & 17.01.2019:

Informed to the contractor to attend the remarks vide Lr.No.EE/400 KV Construction/

ATP/ F.UKDSS/D.NO.245/2018,Dt:12-07-2018.

Pending

14 Mail dated 03.08.2018:

Smoke detection problem rectified.

Complied

It is observed that earth-resistance for various identified Points of station earth-mat have been measured in 2016. It is recommedned to measure

these earth resistances on yearly basis, and maintain relevant records with suitable earth lay-out diagrams.

It is obsereved that metal spreading has not been provided in HV & LV side bays of ICT-3 and ICT-4. Since these bays have already been kept in

operation, it is recommended to take up this job on priority basis so as to ensure safety for the working personnel by maintaining touch & step

potentials within limits.

Smoke detection systems have been found to be either not installed or not in working condition in 220 kV kiosks. It is recommeded to rectify the

same, and put them into operation at the earliest.

Automatic supply changeover from AC auxiliary supply to DG set may be provided. Also remote starting of DG set may be provided from control room

SCADA

6/95

Annexure-VI

Page 6 of 95

15 Mail dated 17.01.2019:

Completed

Complied

16 Mail dated 17.01.2019:

Completed

Complied

17 Mail dated 03.08.2018:

Cable trenches covered properly.

Complied

18 Mail dated 03.08.2018 & 17.01.2019:

Applied for BSNL BB connection.

Pending

19 Mail dated 03.08.2018:

Rectified and now all relays are communicating with SAS.

Complied

20 Mail dated 03.08.2018 & 17.01.2019:

PR raised by ADE/ Telecom/ATP for purchase of the same.

Pending

21 Mail dated 17.01.2019:

Completed (No diagram was given)

Pending


Equipment/ System

auditated


Constituent)

1 Control and

Protection Panels

Main 1 & Main 2 distance relay are of same make, Type & model in Miryalaguda and

Shapoornagar feeders .


Main –I & Main-II different make/model of Miryalaguda and Shapoornagar feeders

relays were procured and it will be replaced whenever LC is available by deputing the

service engineer




service engineer with in three months.




service engineer with in three months.

Pending

2 DC supervision relays are not availble for all feeders. Mail dated 30.01.2018

DC supervision relays for all the feeders were commissioned.

Complied

3 For 220 KV Busbar protection,one number of main distributed Bus bar protection scheme and

inbuilt Check Zone protection is available. CT supervision relays are not seperately provided.

Mail dated 30.01.2018

220 KV Bus bar Protection Scheme through differential current Alarm CT supervision

was provided.

Complied

4 220 kV Tie line-2 main-1 relays is of static relays (ABB RADSL). Mail dated 30.01.2018

220 kV Tie line-2 main- I relays were replaced with new RED-670 relays

Complied

5 For 220kV Main 1& Main 2 distance protection same CT core is used. Mail dated 30.01.2018 & 19.07.2018 & 22.01.2019

Due to Phasing out of the Units in 2019, it will not be possible to procure the new CTs

with two protection cores.

Pending

Door-to-Panel earthing may be provided in various control & marshalling boxes

Visual display indicating bay-element names may be suitably provided for all 400 kV & 220 kV bays.

Cable trenches in the switchyard should be covered properly. Control Cables & Power Cables may be properly segregated in different trays provided

in the cable trenches.

It is observed that Substation is not having Internet connectivity. Steps may be taken to provide the same to enable substation personnel to

discharge their official duties effectively.

It is observed that some of the relays not communicating with SAS Work Station, which may be rectified.

Walkie-talkie system for yard communication is not available, which may be provided.

TSGENCO

1 (i) 220 kV KTPS (O&M) [14-16 March, 2016]

The pending protection audit recommendations of 220 kV KTPS (O&M) were discussed in PCSC-76 meeting held on 26.07.2018. TSGENCO informed that this plant would be phased out by the end of 2018, and requested to drop all the pending Items. To this, PCSC forum

asked TSGENCO to communicate the same through proper channel to MS, SRPC for taking appropriate action. In that letter, clarity may also be given regarding what would happen to the existing equipment & feeders emanating from this plant.

The pending protection audit recommendations of 220 kV KTPS (O&M) were discussed in PCSC-81 meeting held on 24.01.2011. Since TSGENCO informed that this plant would be soon phased out, and requested to drop all the pending Items, PCSC forum asked TSGENCO to

communicate the same through proper channel to MS, SRPC for taking appropriate action. In that letter, clarity may also be given regarding what would happen to the existing equipment & feeders emanating from this plant.

AC Supply Changeover Scheme for the Substation may be provided

7/95

Annexure-VI

Page 7 of 95

6 Remote indication of WTI and OTI of IBT-3&4 not provided in control room. Mail dated 30.01.2018 & 19.07.2018 & 22.01.2019:

As per the existing OT&WT gauges it is not possible to provide the remote indication at

control room

Pending

7 Smoke detection system is not available in control room building. Mail dated 30.01.2018 & 19.07.2018 & 22.01.2019:

Due to Phasing out of the Units in 2019 it will not possible to implement smoke

detection system

Pending

8 Relay Setting Auto-reclose feature is not enabled for 220kV lines. Mail dated 30.01.2018

Auto-reclose feature for all 220kV lines will be enabled soon.


It requires two more months for commissioning and testing of new relays and to keep

Auto Reclosure in service.


in view of phasing out of the units, the implementation of the scheme in 220 KV

generating stations is under discussions regarding relay settings & mapping

Pending

9 Zone time setting & Resistive reach setting for distance protection are found to be different

from the recommanded setting given by Tractebel based on Ramakrishna committee

recommendations (Task force committee guidelines).

Mail dated 30.01.2018 & 19.07.2018 & 22.01.2019:

All the feeder settings were followed by as per the CE/ PowerSystems/TSTransco

Recommendations only.

Pending

10 PSB was kept blocked for all zones. Mail dated 30.01.2018 & 19.07.2018

Followed as per the CE/PowerSystems /TSTransco Recommendations


Updated as per the CE/PowerSystems /TSTransco Recommendations

Pending

11 All distance protection zones are set as forward Direction and Reverse zone is not provided

in distance relay (Main-1 & Main-2) for Nunna,Manuguru-1&2,Tie line-1&2 feeders.


followed as per the CE/PowerSystems /TSTransco Recommendations

Mail dated 19.07.2018 & 22.01.2019:

followed as per the CE/PowerSystems /TSTransco Recommendations and reverse zone

provided for Tie line-1&2 feeders.

Pending

12 For 220kV Tie line-1&2, STUB function is in activated condition in Main-2 distance relay (REL-

100)


Tie line 1&2 REL-100 relays were replaced with RED-670 & MICOM P442 relays.


REL 100 relay was Replaced with micom p442 relay in that stub protection not there.

Complied

13 Carrier aided protection is available only in Nunna feeder and is not provided for any of the

220kV feeder due to non-availability of PLCC/ Wave trap.


Carrier aided protection for all Feeders panels were commissioned and relay mapping

will be done by deputing service Engineer.



will be done by deputing service Engineer with in one month.



will be done by deputing service Engineer.

Pending

14 AC Distribution Auto Changeover is not available in ACDB for 415V Auxiliary supply 1 & 2. Mail dated 30.01.2018 & 22.01.2019:

As per the existing scheme AC change over was not available

Pending

15 DG set is not available to cater to substation loads.TSGENCO informed that procurement of

DG is under progress.

Mail dated 30.01.2018 & 19-07-2018

From the existing DG set one source was connected to emergency loads of 220 KV

switch Yard.


All the emergency loads of 220 KV switch Yard connected from the existing DG set

one source .

Pending

16 DC Distribution One source of 110V DC supply only available for substation loads and one DC source only

used for Trip coil 1 & 2.,

Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

As per the existing scheme only one 110 V DC source was available.

Pending

8/95

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Page 8 of 95

17 Earth leakage is observed in KTPS(O&M)-A station.The measured values at battery is as

below:

P-N:114.6V ; P-E:110V ;N-E:1.3V;


Earth leakage of KTPS –‘A’ station was identified in 220KV Bus coupler Bay and it was

isolated.

Complied

18 Acid leakageand bulging of batteries is observed in KTPS(O&M)-C station 220V batteries. Mail dated 30.01.2018

Failed batteries in KTPS(O&M)-C station were replaced with new batteries.

Complied

19 Communication

system

Common PC with auto downloading facility for relays DRs is not available. Mail dated 30.01.2018 & 19-07-2018

As per the existing scheme it was not provided.


It was not provided Due to Phasing out of the Units in 2019,

Pending

20 GPS is not available. Mail dated 30.01.2018

GPS was commissioned and it was time synchronized with the numerical relays.

Complied

21 Stand alone EL is not availble. Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

EL was not available in the existing scheme.

Pending

22 DR is not available for 220kV Tie line ckt-1 & 2. Mail dated 30.01.2018

220 KV Tie-1&2 old RADSL relays were replaced with new RED-670 & Micom P442

relays and now they are provided with DR.

Complied

23 Redundancy not maintained in Fibre optic termination equipment. Mail dated 30.01.2018

Fiber optic termination equipment redundancy was provided.

Complied

24 PLCC protection couplers are not availbale for 220kV lines except Nunna feeder. Mail dated 30.01.2018

For all 220KV feeders PLCC protection Couplers were provided.

Complied

25 220kV Switchyard Field

Equipments

Wave trap is available only in Nunna feeder. Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

Wave traps are available for all the feeders except Miryalaguda feeder.

Pending

26 Lightning Arrestor Earthing is not done as per standards/ NFPA in the most of 220kV bays.

LA's (system) earthing is connected to earth electrodes directly as well as through equipment

earthing. Healthiness checking (leakage current measurement) of Lightrning Arrestor is not

being done.


As per the standards LA Earthing is provided directly.

Complied

27 In most of the 220kV bays, LA surge counters and monitors (Nunna,IBT3 & 4,Tie

line,Miryalaguda) are not in working condition.


LA surge counters and monitors were replaced with new ones.

Complied

28 In 220kV Nunna line Y phase CVT is not available. Mail dated 30.01.2018

220 KV Nunna line Y-Phase CVT will be replaced

soon.


220 KV Nunna line Y-Phase CVT will be replaced with in two month.


220 KV Nunna Line Y-Phase CVT will be replaced within 3 Months.

Pending

29 In 220kV Bus Coupler-II Y phase CT is not available. Mail dated 30.01.2018

220 KV Bus Coupler-II Y-Phase CT will be replaced soon.


220 KV Bus Coupler-II Y-Phase CT will be replaced with in two montsh.


220 KV Bus Coupler-II Y-Phase CT will be replaced within 3 Months.

Pending

30 Walkie-talkie system for yard communication is not avalable. Mail dated 30.01.2018

Walkie-talkie system for yard communication was provided.

Complied

31 Lot of Grasses and other weeds are found over the Gravels in the 220kV KTPS-A & C yard. Mail dated 30.01.2018

Grasses and other weeds were removed over the grounds in 220 KV KTPS-A & C

yards.

Complied

9/95

Annexure-VI

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32 Air pressure low alarm checking was done for Buscoupler bay breaker. CB trouble/ air

pressure low alarm did not get activated in controlroom.


CB trouble/Air pressure low alarm card was replaced with new one and it is found OK.

Complied

33 It is observed that line CVT structures corroded in Miryalayaguda bay. Action may be taken

to rectify the same.


Line CVT corroded structures were cleaned and painted.

Complied

34 For few 220kV bays, it is observed that the Marshalling box and indication window of circuit

breakers are not visible.


Marshalling Box and Indication window of circuit breakers were provided.

Complied

35 Bay identification codes/name and phase identification are not visible. Mail dated 30.01.2018

Bay identification codes/names and phase identification were provided

Complied

36 Oil leakage was observed in 220kV IBT 3 & 4 bushing turrets and oil inlet pipes. Mail dated 30.01.2018

Oil leakage was arrested for IBT-3&4 and also IBT-3 transformer was replaced with

100MVA transformer from TSTRANSCO.

Complied


Equipment/ System

auditated


Constituent)

1 Control and

Protection Panels

On 220 kV side, Only Single Bus bar protection scheme is available (High impedance Static

type - ABB RADSS) for each of the two buses . No redundant main 2 or Check zone

protection available. CT supervision provided as inbuilt feature. No DR is available.


Planning to replace total 220kv bus bar protection panels in the upcoming R&M at

KTPS-V 220 KV switchyard.


Indent PR No.1000025062; Dt: 12-06-2018 (The task will be completed after the

material receipt for the above Indent).


Procurement of Numerical Bus-Bar Protection Relay scheme is under process. Task will

be completed after the receipt of material.

Pending

2 Relay Setting Auto-reclose feature is not enabled for 220kV lines. Mail dated 30.01.2018

Tie Lines-I&II: As these lines are connecting between generating sub stations, we

are not implementing Auto Reclosure scheme on these lines as per reference minutes

of the 62nd meeting of PCSC held on 15.03.2017.

Budidampadu-I&II and Lower Sileru-II: For these lines the Auto Reclosure

scheme is configured and ready to enable in our substation. Once the other end

substations complete the implementation process we can enable the scheme on our

side. We are also in ther process of negotiation with the OEM's of Relays for testing of

the scheme.

Sitarampatnam-I&II: As per SRPC recommendation it is decided to implement Line

Differential Protection Scheme on these Lines (having Line length less than 10 KMs).

For this we need to replace the existing distance Relays with Differential Relays. We

are in the process of procuring the Differentioal Relays. We will implement the A/R

scheme in the new Differential relays. In the existing distance Relays we are

configured A/R feature and to enable in our substation once other end S/S complete

the implementation process.


Ready to implement, awaiting for reply from TSTRANSCO to enable the Auto-Recosure

function for Sitarampatnam-I&II, Budidampadu-I&II 220KV Feeders.


Tie Lines-I&II: As these lines are connecting between generating sub stations, we are

not implementing Auto Reclosure scheme on these lines as per reference minutes of

the 62nd meeting of PCSC held on 15.03.2017.

Budidampadu-I&II: For these lines the Auto Reclosure scheme is configured and

will enable during the Annual overhaul.

Sitarampatnam-I&II: LDP relays were procured under PSDF scheme and will be

replaced as when LC is available.

Pending

1 (ii) 220 kV KTPS (Stage-V) [14-16 March, 2016]

10/95

Annexure-VI

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3 PSB was kept blocked for all zones. Mail dated 30.01.2018

It is enabled for all zones in our latest Numerical Relays of 220KV feeders in KTPS-V

switchyard.


Remarks attended and communicated via Mail dated 30-01-2018. The task was

completed.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. PCSC

forum asked TSGENCO to verify whether PSB is kept blocked for all Zones

execept Zone-1 with an unblocking time delay of 2 sec without fail, and

confirm implementation of the same.


TSGENCO implemented the settings and verified PSB is kept blocked for all zones

except Zone-1.

Complied

4 Zone time setting & Resistive reach setting for distance protection are found to be different

from the recommended setting given by Tractebel based on Ramakrishna committee

recommendations


The settings provided by TSTRANSCO were configured in all our latest Numerical

Relays of 220kv feeders in KTPS-V switchyard.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. TSGENCO

was asked to confirm whether the reactance reach & resistive reach & time

setting of various Zones of distance relays are in line with Ramakrishna

Committee guidelines. If not, TSGENCO was aske to take steps to bring the

former in line with the latter.


Will verify the settings and intimate the same

Pending

5 The distance protection for all 200 kV feeders (except for REL670) was configured with 3

zones (forward) zones only. There was no reverse-zone available for the distance protection

provided on 220 kV feeders.


Four forward and one reverse Zones were configured in our latest Numerical relays of

220KV feeders in KTPS-V switchyard , which are provided by TSTRANSCO.

Complied

6 For Budidampadu line-1 and Lower sileru line-2 , STUB function is in activated condition in

Main-1 distance relay (REL-100) and binary output is not configured.


In KTPS-V 220KV swichyard , Budidampadu line-1 and lower sileru line-2 STUB

function is in deactivated condition in Main-1 distance relay which are replaced with

REL-670 Numerical relays.

Complied

7 Carrier aided protection is available only in Budidampadu feeder-2 and is not provided for

any of the 220kV feeder due to non-availabilyi of PLCC/ Wave trap.

Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

New PLCC panels for all 7 No.220KV feeders at KTPS-V stage swichyard were installed,

But commissioning is under progress and it is in scope of TSTRANSCO.

Pending

8 DEF protection not available in Budidampadu-1 feeder. Mail dated 30.01.2018:

It is configured in latest Numerical relays of all 7 No.220KV feeders at KTPS-V stage

swichyard.

Complied

9 Main-2 distance relay (Make ABB, Type - REZOA) is of static type in 220 kV Sitaramapatnam-

1&2, Budidampadu-1&2 and Lower sileru-2 feeders. Relay does not have DR feature, cannot

be time synchronized with GPS and there is no provision for additional features in these

relays


In 220KV feeders of KTPS-V SWITCHYARD, Main-2 distance relay (Make ALSTOM

make MICOM P442) is in service for Sitaramapatnam-1&2, Budidampadu-1&2 and

Lower sileru-2 feeders which has DR feature and can be time synchronised with GPS

and there is provisions for additional features in these relays.

Complied

10 AC Distribution DG set not available to cater substation loads.TSGENCO informed that entension of supply

from generating station DG will be planned shortly.


Indent for DG set is raised at KTPS-V 220KV swichyardand it is in procurement stage.

Mail dated 19-07-2018:

Procurement is under process


PO placed , material yet be received.

Pending

11/95

Annexure-VI

Page 11 of 95

11 DC Distribution One source of 48V DC system is available.TSGENCO informer that commisioning of second

source of 48V DC system is under progress.

Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

In KTPS-V 220KV stage swichyard Second 48V battery bank also available with same

charger. Second charger procurement is under process.

Pending

12 Communication

system

Common PC with auto downloading facility for relays DRs is not available. Mail dated 30.01.2018 & 19-07-2018:

For all KTPS-V stage swichyard, Separate Laptop is maintaining for Relay

configuration,retreiving DRs and Els.


was aksed to take steps to provide provision for Common PC with auto-

downloading facility for relays' DRs.


For all KTPS-V stage swichyard, Separate Laptop is maintaining for Relay

configuration,retreiving DRs and Els.

Pending

13 GPS is not available. Mail dated 30.01.2018:

For KTPS-V 220KV swichyard, Indent is raised and it is in procurement stage.


Procurement is under process.


PO placed under PSDF scheme, Commissioning will be carried after recipt of material.

Pending

14 Stand alone EL is not availble. Mail dated 30.01.2018:

For all 220KV feeders of KTPS-V swichyard, Stand alone EL is available with latest

Numerical Relays.

Complied

15 The communication with the only numerical relay (ABB REL670/RED670) is available.

Interfacing cables for relay setting and DR extraction is not availble for REL 511 relays.


In KTPS-V Switchyard, 220KV Feeder REL511 Relays were retrofitted with ALSTOM

make MiCOM P442 Numerical Relays.

Complied

16 Redundancy not maintained in Fibre optic termination equipment. Mail dated 30.01.2018:

In KTPS-V Switchyard, new PLCC equipment installed for all 220KV Feeders which are

having redundancy in fibre optic termination equipment.

Complied

17 PLCC protection couplers are not availbale for 220kV lines except Budhidampadu feeders. Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

In KTPS-V Switchyard, new PLCC equipment installed for all 220KV feeders it is under

commissioning stage and it is in scope of TSTRANSCO.

Pending


Equipments

Wave trap available in Sitaramapatnam-1&2 (inter circuit coupling and in Budidampadu

feeder-2. Wave trap is not available in other 220kV feeders.

Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019 :

In KTPS-V 220 KV Switchyard, Wave traps are available for BDPD-I & II, SRPM-II, LSR-

II feeders(SRPM-II has 2 wave traps), only SRPM-I feeder doesn't have wave-trap.

The issue was discussed in PCSCM-76 held on 26.07.2018 and PCSCM-81

held on 24.01.2019. TSGENCO was asked to ensure that wave traps are

provided in all 200 kV feeders, and confirm the same.

Pending

19 Even though the designed 220 kV busbar arrangement has bus-1 & bus-2 & transfer bus, the

transfer bus was kept out of service due to the low SF6 pressure in transfer bus circuit

breaker.


In KTPS-V 220KV Switchyard, the Transfer Bus is in healthy conditions (all its

interlocks also checked). Now breaker is filled with required SF6 gas pressure.

Complied

20 Lightning Arrestor Earthing is not done as per standards/ NFPA in the most of 220kV bays.

LA's (system) earthing is connected to earth electrodes directly as well as through equipment

earthing. Healthiness checking (leakage current measurement) of Lightrning Arrestor is not

being done.


In KTPS-V 220KV Switchyard, earthing for LA's were provided as per the standards and

leakage current monitoring is recording every quarterly.

Complied

21 In most of the 220kV bays, LA surge counters and monitors are not in working condition. Mail dated 30.01.2018:

In KTPS-V 220KV Switchyard, Indent is raised for LA's surge counters and monitors

and it is in procurement stage.

Mail dated 19-07-2018:

Procurement is under process


PO placed under PSDF scheme, work will be carried after recipt of material.

Pending

12/95

Annexure-VI

Page 12 of 95

22 Walkie-talkie system for communicating with Control room personnel is not provided. Mail dated 30.01.2018 & 19-07-2018 & 22.01.2019:

In KTPS-V 220KV Switchyard, Walkie-Talkie system will be procured shortly, presently

dedicated Mobile phones are available location-wise (MCR, UCB)

Pending


Equipment/ System

auditated


Constituent)

1 Relay Setting Stub protection current set and time delay set as I> 150% and 100ms. Mail dated 30.01.2018:

stub protection current set value and time delay value are I>150% and 0 ms


Setting adopted


was sked provide Stub Protection Settings as I>250 % and time delay equal

to 50 ms.


Settings adopted.

Complied

2 Main-1 relays all five zones are looking forward direction.No reverse zone provided.

In Main-2 relays four zones are kept in forward direction and Zone-5 is of reverse direction.


Reverse Zone protection for main-I provided

Complied

3 AC Distribution DG set is not available to feed substation loads.TSGENCO informed that extension of supply

from generating station DG will be planned shortly.


Supply extended from Generating Station DG

Complied

4 DC Distribution 2nos, 220 V DC system each with one Battery chargers , one no of Battery bank and one

DCDB with Bus couplers are available. Each set will feed Trip circuit 1 and Trip circuit 2

separately. In the event of failure of one set , Buscoupler will be closed manually to extend

supply to the affected section.


Presently existing system with buscoupler will be closed manually to the affected

section.

Complied

5 Communication

system

Common PC with auto downloading facility for relays DRs is not available. TSGENCO

informed that dedicated PC is available but not in working condition at present.


Auto downloding yet to be configured, presently it is manual download


Planning to proccure software.


Comminicated with M/s Siemens regarding Distro software and asked for budgetary

offer.

Pending

6 GPS is not available. TSGENCO informed that PST feeder protection relays are time

synchronised with Generating station GPS.Other feeder relays are not time synchronised and

procurement of GPS is under progress.


GPS Commissioned. All relays are synchronized.

Complied


Equipments

Lightning protection (LA's) Earthing is not done as per standards/ NFPA in the most of 400kV

bays. LA's (system) earthing is connected to earth electrodes directly as well as through

equipment earthing.


LA's Earthing is provided with Earth mats seperately and these mats are connected to

system earth.

Complied

8 Emulsifier system for fire fighting of Phase Shifting Transformer is not in healthy condition

and Local indication are not available.


Rectified Emulsifier System.

Complied

9 Oil leakage is observed in PST shunt and series transformer inlet pipelines to tank. Mail dated 30.01.2018:

Attended and Rectified

Complied

10 Drainage system in switchyard is not properly maintained.Water logging in cable trenches

has been observed and submerged drain pump also not in working condition.


Pumps are working found Normal

Complied

11 PST-Shunt HV side WTI meter is not calibrated. Mail dated 30.01.2018:

Calibrated

Complied

1 (iii) 400 kV KTPS (Stage-VI) [14-16 March, 2016]

13/95

Annexure-VI

Page 13 of 95

12 Bay identification codes/name and phase identification are not visible. Mail dated 30.01.2018:

Name plate Boards are fixed with new one.

Complied

13 Walkie-talkie system for communicating with Control room personnel is not provided. Mail dated 30.01.2018:

Provided Walkie-Talkies

Complied


Constituent)

1 Mail dated 19.03.2018:

Implemented

Complied

2 Mail dated 19.03.2018:

Revised

Complied

3 Mail dated 19.03.2018:

Already ensured.

Complied

4 Mail dated 19.03.2018:

As per ramakrishna committee recommendations, revised to All zones blocking except

zone-1.

Complied

5 Mail dated 19.03.2018:

Already ensured.s

Complied

6 Mail dated 19.03.2018:

AR feature implemented for all 220KV Feeders, except 220KV Pargi-1 &2 . The work is

under progress, will be implemented by end of March, 2018


Auto Reclosure feature is provided on all the 220kV feeders.

Complied

7 Mail dated 19.03.2018:

Auto Change over is provided.

Complied

8 Mail dated 19.03.2018:

Only one BUS Bar C.U. is enough as per the existing philosophy

Complied

9 Mail dated 19.03.2018:

Will be implemented in 15 days.


Will be implemented by end of July 2018.

Pending

10 Mail dated 19.03.2018:

Under progress. Will be implemented in coordination with remote end substations

within 2 months

Pending

11 Mail dated 19.03.2018:

Already ensured

Complied .


Constituent)

1 Yet to be informed Pending




1) 400/220/132 kV Gajwel SS [30-31 October, 2018]

Remarks/Deficiences/Nonconformity observed

Remarks/Deficiences/Nonconformity observed

The existing Power Swing Philosophy (with all Zones blocked for unblocked time delay) to be reviewed to adopt either of the following two

approaches:

(i) Zone-1 --> Trip; Highers Zones --> Block for a delay of unblocking time delay (2 sec) & then Trip


Load Encroachment feature, though explicitly not available in P444, has been taken care of by maintaining sufficient marign beween Zone-4 resitive

reach and expected load resistance.

Auto-Reclosure feature in 220 kV lines may be provided as decided in SRPC meetings

Provision of auto supply changeover to BBP may be explored

Bus Bar protection at each ovoltage level (220 kV/ 400 kV) for all Zones has been provided in P741 relay

VT Fuse File operation to be made independent of Over Current (67) functionality in Main-I & Main-II relays of all 400 kV & 220 kV feeders. Case my

be referred to OEM, if required.

VT Fuse fail time delay, which has been presently kept at 0.8 sec, may be suitably revised to say 0.5 sec

Drop-Off to Pick-up ratio of Over-Voltage functionality of Main-I & Main-II relays to be ensured at > 0.97.

It is seen that Auto-Reclosure functionality is yet to be provided in 220 kV transmission lines. Steps may be taken to expedite the same.

In 400 kV & 220 kV Circuit Breakers, Re-Trip feature has not been provided for LBB protection. The same may be provided.

In some of the 220 kV lines (Minpur -2, Medchal - 1 & 2) LBB protection has been implemented from one of the two Main relays. This may be

provided from both the Main relays or from an external LB relay.

Backup DEF and O/C protections have not been provided in 220 kV Minpur-1 and 220 kV Kamaeddy line. However, TSTRANSCO informed that relays

panels for the said lines are under replacement. After replacement, the requred protections would be enabed from the new relay panels

Provsision for auto-starting of DG set shall be provided

In 400 kV lines, distance protection timings for Zone-2, Zone-3, Zone-4 and Zone-5(reverse) may be reviewed in line with Ramakrishna Committee

guidelines

High-set operation of ICT's may be checked to ensure their non-operation for downstream/ upstream faults

1) 400/220 kV Shankarapally SS [20 - 21 March, 2017]

TSTRANSCO

14/95

Annexure-VI

Page 14 of 95


















The following equipment may be purchased/ provided for maintenance of various switchyard equipment:

(i) THRC kit for LA testing

(ii) DC leakage detection kit

(iii) Universal relay testing kit

(iv) Digital Earth-Resistance Tester

(v) 10 kV Insulation Resistance Tester

Time synchronization of Protection relays with GPS has not been provided for 220 kV & 132 kV elements. Steps may be taken to provide the same.

It is observed that DG-Set starting and Supply changeover among AC supplies & DG set are being done manually. Steps shall be taken to provide

them in auto-mode.

It is noted that one no. of Lightining Mast at the boundary of 400 kV & 220 kV switchyards has been dismantled during commissioning of 125 MVAR

Bus Reactor. Steps may be taken to erect the same at the earliest so as to provide adequate protection from lightning & thunder storms.

It is seen that each of the two sets of DC Battery & Battery Chargers provided for PLCC panels have been catering to half of the full load. Steps may

be taken to increase the capacity of these Battery & Battery Sets so that each set is capable of catering to full load.

In the document furnished on measured earth pit resitances, earth resistance values for few earth pits in 400 kV switchyard are observed to be on

higher side. Steps may be to taken bring them within mandated limits. Further, it is also recommended to carry out measurement of earth-

resistances of all earth pits (400 kV & 220 kV & 132 kV switchyards) on yearly basis, and keep updated records with the substation along with

suitable earth-mat lay-out diagrams.

It is recommended to configure Disturbance Recorder (DR) and Event Logger (EL) of various protection relays to record all mandated protections &

digital signals.

It is observed that certain cables & cable trenches have not been properly covered in 220 kV & 132 kV switchyards, which may be attended

appropriately.

Equipment labeling for Bay Elements (feeders & transformers) may be provided in all 400 kV & 220 kV & 132 kV switchyards. Also Labeling on

various Relay Panels may be corrected as per latest existing configuration.

Walkie-talkie system for yard communication is not available, which may also be provided.

It may be ensured that Main and Backup protections in various feeders have been provided from differnt DC supplies.

It may be ensured that HV side and LV side protections on various transformers have been provided from differnt DC supplies.

REF protection & Fire Protection have not been provded on 100 MVA, 220/ 132 kV Tranformers. Steps may be taken to provide the same or suitable

explanation for not providing the same may be given.

It is seen that instead of the desired Single bus & Transfer bus type of bus configuration, Single Bus type of bus configuration has been provided for

132 kV Buses. Steps may be taken to provide the same or suitable expanation for not providing the same may be given.

It is noted that the following details have not been provided by TSTRANACO:

(i) Details of 400 kV & 220 kV & 132 kV CT's Ratios and Errors & Knee-point voltages

(ii) Details of 400 kV & 220 kV & 132 kV VT's Ratios and Errors

The filled in details shall be provided within 10 days.

220 V Battery Units and Battery chargers have been housed in the same room along with other relay panels. Suitable partition may be provided

between them

The Zone-5 (Reverse-Zone) time settings may be changed from the existing "1" sec to "0.5 sec".

15/95

Annexure-VI

Page 15 of 95


Equipment/ System

auditated

Deficiences/Nonconformity observed Status of Implementation of Protection Audit Recommendations Remarks Latest Status (To be filled in by the

Constituent)

1 Main-1 &

Main-2 Bus

220KV Protection Single Bus operation is being done for 220kV Switchyard. Two main Buses (1 Working + 1

Standby) to be provided in the 220KV.


Time frame is requested for 2 yrs. To carry out 220Kv double bus operation using

Num relay under PSDF funds

Mail dated 24.07.2018 & 23.01.2019:

Work proposed to be taken up under PSDF. Approval from Nodal agency is awaited.


Pending

2 All Line Feeders 220KV Protection Carrier Protection was kept off in all 220KV feeders. PLCC provided in 220KV feeders. KPCL

informed that retrofitting of new 48V DC system is under progress.


The retrofitting of new 48V DC system was completed during July-2016. PLCC system

in RTPS is monitored and maintained by KPTCL. At present KPTCL staff are working on

the PLCC system.

Mail dated 24.07.2018 & 23.01.2019:

Work is under progress (by KPTCL).

Pending

3 ICT-2 220KV Earthmat Resistance Earth resistance values of earth pit of lines were observed to be higher. Mail dated 14.02.2018:

M/s CPRI was awarded the work of earth mat adequecy study at 220/400KV

switchyard. Their conclusion is as follows. "A detailed study of earth resistance

measurment, checking the adequacy of existing earthing system and step and touch

potential measurment was made at RTPS. from the measurment results, the

interconnected earth resistance is found to be 0.05ohm which is less than the standard

value of 0.5ohm for a large earthing system. soil resistiviy at the side near the

switchyard is found to be homogenous with an average value 30.02ohm-m. step and

touch potential were made found ti be within the tolerable value. Adequacy checks

have been made at all the locations of RTPS"

Complied

4 Lingasugear -3,

Sadam-1&2

220KV Equipment Wave Trap is not available Mail dated 14.02.2018:

Wave traps are normally provided and commissioned by M/s KPTCL. However the

same is being processed by CEED/CETD under PSD fund.


Wave traps are normally provided and commissioned by M/s KPTCL. However the

same is being processed under PSD fund. Time frame is requested for 2 yrs.

Mail dated 24.07.2018 & 23.01.2019:



Pending

5 General 400KV &

220KV

Control room Fire alarm/detection system is not working in 400KV & 220KV control room. KPCL informed

that retrofitting is under progress.

Mail dated 14.02.2018 & 21.02.2018:

Action has been taken for retrofitting works.


New fire alarm/detection system is provided in the control room and working

Complied

6 SHAHAPUR-1&2 220KV Protection Its observed that the Only one Main relay is used in the 220KV Shahapur-1&2 (ABB REL100

in Shahapur-2 line feeder and ENGLISH ELECTRIC - QUADRAM40 in Shahapur-1 line feeder).

These relays are very old one and static type. There is no reverse Zone selection in these

relays and Only one DC source is being used


The old Distance Protection relays of Shahapur 1&2 lines were retrofitted with

Numerical relays during July-Aug 2016. ABB REL511 for Main-I and Alstom MiCOM

P444 for Main-II distance protection.

Complied

1) 400 Raichur TPS & 220 kV Raichur TPS [8-10 June, 2016]

KPCL

16/95

Annexure-VI

Page 16 of 95

7 Raichur-1&2,

Lingasuguar-1&2

220KV Protection In Raichur-1&2 and Lingasuguar-1&2 220KV line feeder DEF provided only in the Main-2

relay.


ABB REL511 and MiCOM P444 relays are in service for Raichur-1&2 and Lingasuguar-

1&2 lines as Main-I & Main-II Dist. Protn. respectively. DEF is provided in the Main-2

relay and the same will be enabled in the Main-I relay after retrofitting old REL511

relays with latest version numerical relays under PSDF funds. Time frame is requested

for 2 yrs.

Mail dated 24.07.2018 & 23.01.2019:



Pending

8 Lingasuguar-3,

Sadam-1&2

220KV Protection DEF not enabled in Main1&2 relay in the Lingasuguar-3, Sadam-1&2 line feeder. Separate

Earth Fault relay (static type) provided.


DEF is enabled in MiCOM P444 (Main-II Dist. Protn.) relay and also separate ABB make

E/F relay RAPDK is existing.

Complied

9 Line Feeders 220KV Protection Auto-reclose feature is not enabled for 220kV lines. Mail dated 21.02.2018:

Auto-reclose function is configured and tested for all the nine lines in Main-II

numerical relays. At present, as per the requirement of KPTCL, Auto-reclose function is

disabled.

Mail dated 24.07.2018 & 23.01.2019:

Auto-reclose function will be enabled as per the requirement of KPTCL.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. KPCL was

clarified that provision of Auto-reclosure is system requirement in line with

the prevailing protection standards, hence should take steps provide the

same at the earliest.


Auto-reclose function will be enabled as per the requirement of KPTCL.

Pending

10 General 400KV &

220KV

Equipment It was observed that stand alone Disturbance Recorder with automatic downloading facility

to centralized PC not provided for static relays.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been invited for retrofitting work of balance static relays with Numerical

protection relays and will be completed by June-2018. Budgetary offer obtained for

Retrofitting of stand alone Disturbance recorder and is under process.

Mail dated 24.07.2018 & 23.01.2019:

Work Order placed on M/s GE T&D India Ltd ,for retrofitting work of balance static

relays with Numerical protection relays and will be completed by October-2018.

Budgetary offer obtained for Retrofitting of stand alone Disturbance recorder and

obtaining approval is under progress.

Pending

11 General 220KV Equipment No time Synchronisation in the 220KV system, GPS not avilable. Mail dated 21.02.2018:

GPS system was installed during Aug-2016

Complied

12 Bus Bar 400KV Equipment Two Main zones are available for busbar protection of 400kV Bus-1 and Bus-2. No check

zone is available.

Mail dated 14.02.2018 & 21.02.2018:

Action has been taken for Retrofitting of Numerical Bus bar protection relays and the

same will be reviewed and will be completed by December 2018.

Time frame is requested for 2 yrs.

Mail dated 24.07.2018 & 23.01.2019:

DPR for retrofitting of Numerical Bus bar protection relays for 400kV bus system has

been prepared. Work proposed to be taken up under PSDF. Approval from Nodal

agency is awaited. However, arrangements have been made to issue NIT.. Time frame

requested for is 2 yrs.

Pending

13 Raichur PG-1 &2 400KV Protection Resisitive reach is set at a higher value in 400KV Raichur PG-1 & 2 feeder, Load

encroachment is not available.


As per PGCIL directions, Revised settings for resistive reach and load encroachment

have been uploaded on 24-06-2016.

Complied

14 Raichur PG-1 &2 400KV PLCC Its observed that the channel failure alarm indication in Raichure PG-2 line Chennel-1 &

Raichure PG-1 line Channel-1&2.


Same has been set-right and both the channels of Raichur PG-1 & 2 are healthy.

Complied

17/95

Annexure-VI

Page 17 of 95

15 ICT Protection Backup over current and earth fault protection of ICT's is kept non-directional. Mail dated 14.02.2018:

Settings will be revised in co-ordination with KPTCL & OEM.


Settings will be revised in co-ordination with KPTCL & OEM during annual shut down of

respective equipments.


Settings has been revised for ICT-1 & ICT-2 on 30.05.2018 & 23.05.2018 respectively

to incorporate the back up O/C & E/F protection as Directional.

Complied

16 All Line Feeders 400KV Protection Stub protection Kept off in 400KV lines Main-1&2 relays. But Separate relay (Static type)

provided for the same. Stub protection set value as 0.2A and time delay is instantaneous.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been invited for retrofitting work of the balance static relays with

Numerical protection relays in which enabling of stub protection is included and the

will be completed by June-2018.


Work Order placed on M/s GE T&D India Ltd, for retrofitting work of balance static

relays with Numerical protection relays in which enabling of stub protection is included

and the work will be completed by October-2018.


Work Order placed on M/s GE T&D India Ltd, for retrofitting work of balance static

relays with Numerical protection relays in which enabling of stub protection is included

and Materials have been received by M/s GE T&D India ltd against WO for the

retrofitting work of balance static relays with Numerical protection relays and will be

completed by February 2019 after availing line shutdown approved by OCC.

Pending

17 Mehaboob nagar &

Munirabad

400KV Protection Auto reclose is not provided for Tie breaker of 400kV Munirabad & Mehaboob Nagar lines.

Pole discrepancy (PD) for Munirabad & Mehaboob Nagar Tie-CB is kept as 0.1sec.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been invited for retrofitting work of the balance static relays with

Numerical protection relays in which enabling of Auto reclose of Tie breaker of

Munirabad & Mahbubnagar line is included and will be completed by June-2018.


Work Order has been placed on M/s GE T&D India Ltd, for retrofitting work of balance

static relays with Numerical protection relays in which enabling of Auto reclose of Tie

breaker of Munirabad & Mahbubnagar line is included and the work will be completed

by October-2018.


Work Order has been placed on M/s GE T&D India Ltd, for retrofitting work of balance

static relays with Numerical protection relays in which enabling of Auto reclose of Tie

breaker of Munirabad & Mahbubnagar line is included and Materials have been

received by M/s GE T&D India ltd against WO for the retrofitting work of balance static

relays with Numerical protection relays and will be completed by February 2019 after

availing line shutdown approved by OCC.

Pending

18 Distance protection adopted resistive reach setting for Zone-2 & 3 is not matching with the

recommanded setting given by Tractebel based on Ramakrishna committee



As per PGCIL directions, revised settings for resistive reach of Zone-2 & 3 have been

uploaded on 24-06-2016 for Raichur PG-1 &2 lines--Completed

Complied

19 Zone-3 time delay is kept as 1.5 sec. Mail dated 14.02.2018:

As per PGCIL directions, revised settings for Zone-3 time delay as 1.5 sec kept on 24-

06-2016 for Raichur PG-1 &2 lines--Completed

Complied


As per PGCIL directions, revised settings for Zone-4 time delay as 0.5 sec kept on 24-

06-2016 for Raichur PG-1 &2 lines--Completed

Complied

21 Directionnal Earth Fault setting kept different in Main 1 & Main 2 Relay Mail dated 14.02.2018:

As per PGCIL directions, Revised settings have been uploaded on 24-06-2016.The

settingsof Directional Earth fault kept same in Main 1 & 2 relays --Completed

Complied

Raichur-1&2 400KV Protection

18/95

Annexure-VI

Page 18 of 95

22 YTPS 400KV Protection Zone-4 time delay is kept as 1.0 sec Mail dated 14.02.2018 & 21.02.2018:




Settings has been revised in co-ordination with KPTCL on 19.04.2018 during the

modification of LILO line of RTPS-YTPS as RTPS-BTPS and Zone-4 time delay is kept

as 0.500sec.

Complied

23 MEHABOOB NAGAR

& MUNIRABAD

400KV Protection Zone-4 time delay is kept as 1.1 sec. Mail dated 14.02.2018 & 21.02.2018:




Settings will be revised in co-ordination with KPTCL & OEM.


Settings will be revised in co-ordination with KPTCL & OEM during next shutdown of

line

Pending

24 MEHABOOB

NAGAR,

MUNIRABAD, YTPS

and All 220KV Line

feeder

400KV &

220KV

Protection In distance protection the adopted resistive reach setting for Zone-1,2 & 3 is not matching

with the recommanded setting given by Tractebel based on Ramakrishna committee


Mail dated 14.02.2018 & 21.02.2018:

For 220kV lines, the settings recommended by CEERT, KPTCL is adopted. For 400kV

lines, Settings will be revised in co-ordination with KPTCL & OEM during annual shut

down of respective equipments.


Settings has been revised for RTPS-BTPS(Earlier RTPS_YTPS) as per KPTCl

recommendations on 19.04.2018. Settings for other lines will be revised in co-

ordination with KPTCL, PGCIL, TSTRANSCO & OEM.


Settings has been revised for RTPS-BTPS(Earlier RTPS_YTPS) as per KPTCL


ordination with KPTCL, PGCIL, TSTRANSCO & OEM during the next shutdown of line.

Pending

25 Zone 4 reach should be set to cover 50% of shortest line connected in RTPC SS (existing

settings are set to 20% of protected line)

Mail dated 14.02.2018 & 21.02.2018:










recommendations on 19.04.2018. Settings for other lineswill be revised in co-


Pending

26 Resistive reach of reverse Zone is not Kept identical with Zone 3 resisitive reach. Mail dated 14.02.2018 & 21.02.2018:












Pending

All Line Feeders 400KV &

220KV

Protection

19/95

Annexure-VI

Page 19 of 95

27 Zone-4 (Reverse Zone) time delay not match with Zone-2 setting. Mail dated 14.02.2018 & 21.02.2018:












Pending

28 General - DC system In DC system +ve Earth fault was observed in 220KV switchyard. The voltage measured

values are :

DC-1

+ve to -ve = 234.6V

+ve to earth = 1.217V

-ve to earth = 233.4V

DC-2

+ve to -ve = 235.3V




Positive dead ground was partially eliminated in Oct-16. The voltage measured values

were:

+ve to -ve = 237.7V



The DC grounding problem is being attended as and when it appears. The DC voltage

measured values in Jan-18 are:

+ve to -ve = 237.7V




Online DC earth fault monitoring system is installed in 220kV ODY. Earth faults are

being isolated as and when occurs.

The existing voltage measured values are

+ve to -ve = 238V

+ve to earth = 103V

-ve to earth = 135V

Complied

29 Mahaboob Nagar

Line Reactor

400KV Equipment Oil seepage was observed in the 400 kV system Line Reactor. Mail dated 14.02.2018:

Oil leakage was arrested during AOH works of M.Nagar line Dec 2016.

Complied

30 General 415V ACDB It is observed that manual Changeover arrangement only has been provided between

Incomer -1 & Incomer-2 feeder in ACDB.

Mail dated 14.02.2018 & 21.02.2018:

It has been deliberated and opined that manual changeover is adequate.

The issue was discussed in PCSCM-76 held on 26.07.2018 and PCSCM-81

held on 24.01.2019. It was clarified to KPCL that manual changeover of AC

auxiliary feeders is not adequate, and asked to provide auto changeover

between them.

Pending

31 General 415V DG set Generation plant emergency DG set is utlised for 400KV auxiliaries during main source

blackout. Manual changeover arrangement only has been provided in the ACDB Main source

and DG source.

Mail dated 14.02.2018 & 21.02.2018:

It has been deliberated and opined that manual changeover is adequate.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. It was

clarified to KPCL that manual changeover between AC auxiliary feeders and

DG source is not adequate, and asked to provide auto changeover between

them.


'Cable has been laid from DG-4 house upto ACDB panels to provide emergency supply.

Pending

32 General 415V DG set No dedicated DG set for 220KV switchyard auxiliaries. Emergency power source not provided

in the 220KV system ACDB during main power supply blackout.

Mail dated 14.02.2018 & 21.02.2018:

Tender has been floated for the work of extension of AC supply from DG-1 Bus to

220KV switchyard auxillaries.


'Cable has been laid from DG-1 house upto ACDB panels to provide emergency supply.

Pending

33 General - Equipment Cables laying in 220KV Switchyard ACDB & DCDB room is observed to be overloaded in cable

trays and some of the cables laid haphazardly (not properly laid in Cable trays)

The issue was discussed in PCSCM-81 held on 24.01.2019. KPCL was asked

to take take appropriate action at the earliest.

Pending

All Line Feeders 400KV &

220KV

Protection

20/95

Annexure-VI

Page 20 of 95

34 General - Equipment In ACDB & DCDB, no Indication Lamps were provided. Mail dated 14.02.2018:

Fused out Indicating lamps replaced.

Complied

35 General - DC system It is observed that dedicated one no. 220V DC system provided in the 220 KV DC auxiliaries.

For other DC supply, Generation plant DC source is being used.


For protection of 220kV feeders, one dedicated 220V DC system is provided and

arrangement is ready to take either of Unit 1, 2, 3 & 4 station 220V DC as a backup.


clsrified to KPCL that second DC source is not for back-up, but for primary

use as the first DC source. As such, KPCL was asked to provide redundant

220 V DC source (Battery & its Charger) independent of Generation plant DC

source.


For protection of 220kV feeders, one dedicated 220V DC system is provided and

arrangement is ready to take either of Unit 1, 2, 3 & 4 station 220V DC as a backup-

The issue was discussed in PCSCM-81 held on 24.01.2019. It was clsrified to

KPCL that second DC source is not for back-up, but for primary use as the

first DC source. As such, KPCL was asked to provide redundant 220 V DC

source (Battery & its Charger) independent of Generation plant DC source.

Pending

36 General - Equipment Most of the circuit breaker cubicles in 400KV & 220KV feeders have not been provided with

panel lamp. Door switches were also not working properly.


Panel lamps have been provided and are visible from the front side of the panel. Failed

door switches are being replaced.

Complied

37 General - Equipment It is observed that single earthing has been provided for few marshalling boxes in

switchyard. Also Door earthing was not provided for few marshalling boxes. The dummy

gland holes in few marshalling boxes were not covered.


One more earthing has been provided to marshalling boxes wherever they were not

existing. Door earthing works completed. Dummy gland holes are plugged with M seal

and Putty.

Complied

38 General - Equipment It was observed that most of unused cutouts in ACDB & DCDB (both 400 kV & 220 kV) in

control room were not covered.


Unsed cut outs covered with dummy fuse carriers.

Complied

39 General - Equipment Drainage system in switchyard is not properly maintained.Water logging in cable trenches

has been observed and submerged drain pump not available.


This has been brought to the notice of EEPCM2/CCET.

Mail dated 21.02.2018 & 23.01.2019:

The problem will be attended in coordination with civil engineers.

Pending

40 General - Equipment It is observed that Silicon coating of 400KV bay equipments not provided. Mail dated 14.02.2018 & 21.02.2018:

Silicon coating of two breakers of Unit-8 has been completed. Other breakers are

under consideration and HO approval awaited.

Mail dated 24.07.2018 & 23.01.2019:



Pending

41 General Equipment It is observed that REL500 series relays are not having time synchronisation facility. Mail dated 21.02.2018:

Proposed to retrofit old REL511 relays with latest version numerical relays under PSDF

funds. Time frame is requested for 2 yrs.

Mail dated 24.07.2018 & 23.01.2019: :

Budgetary offer obtained from M/s ABB. Work proposed to be taken up under PSDF.

Approval from Nodal agency is awaited. However, arrangements have been made to

issue NIT.

Pending


Equipment/ System

auditated


Constituent)

1 Ambewadi-1 Line

Feeder

220KV Equipment Wave Trap is not available. Mail dated 07.02.2018:

Wave traps provided to R & B phases of all the eight lines.

Complied

2) 220 kV Nagjheri PH [14-16 July, 2016]

21/95

Annexure-VI

Page 21 of 95

2 Synchro-check protections not enabled for Line Feeders. KPCL informed that the CVT

erection & commissioning works are in progress & wiring is completed in Relay panel &

synchronizing panel. Will be commissioned at the earliest. Synchronizing relay is available.

Mail dated 07.02.2018 & 21.02.2018:

CVT erection and commissioning works completed. Preparation of wiring scheme is

under progress.


CVT erection and commissioning works completed. Preparation of wiring scheme also

completed.

Complied

3 CVT condition is very old and not in proper condition, only R-ph CVT is present in all the

lines except Ambewadi line#1 which is not having any CVT. KPCL informed that the CVT

replacement works are in progress. Will be commissioned at the earliest


CVT's erected and commissioned for R,Y & B phases and wave traps for R & B phases

of all the eight lines.

Complied

4 Kodasali-1&2 Line

Feeders

220KV Protection It is observed that the ENGLISH ELECTRIC - QUADRAMHO relay is used in the Kodasali-1&2

Line feeders Main-I. These relays are very old one and static type. KPCL informed that the

same will be replaced with in one month.


Replaced by new Schneider make micom P444 numerical relays in both Kodasalli lines

1 & 2.

Complied

5 All Line Feeders 220KV Protection Auto-reclose feature is not enabled for all 220kV lines. Mail dated 07.02.2018 & 21.02.2018 & 21.07.2018:

Auto reclose feature is tested at Nagjhari end along with KPTCL RT, Hubli and is clear

for all the six lines (NA-1, NA-2, NH-1, NH-2, NH-3, NB). Auto reclose function will be

enabled after getting clearance from the receiving end.


AR feaure is avalilable in Main-1 relay in all feeders. However, Letter addressed to site

to take up the proposal for replacement of PZ1000 line distance relays.

Pending

6 All Line Feeders 220KV Protection Pole discrepancy (PD) for all 220KV Line feeders CB is kept as 0.5sec. Mail dated 07.02.2018 & 21.02.2018 & 21.07.2018 & 23.01.2019:

Will be changed after enabling Auto reclose function to 1.7 Sec.

Pending

7 Reverse Zone Not Enabled in the Kodasali-1&2 and Ambewadi-1&2 Line feeders. Mail dated 07.02.2018:

Enabled in Kodasalli lines 1 & 2 and Ambewadi lines 1 & 2 as per the recommended

settings of CEE RT & R & D, KPTCL.

Complied

8 Zone-4 time delay is kept as 2.0 sec. Mail dated 07.02.2018, 21.02.2018 & 21.07.2018 & 23.01.2019:

As per the recommendations of CEE RT & R & D, KPTCL, Zone-4 trip timing is set to 1

second.

The issue was discussed in PCSC-76 meeting held on 26.07.2018.KPCL was

asked to revise Zone-4 timing to 0.5 sec. However, in case of time

coordination requirements w.r.t. Geenrator LT side protections, if any, the

same may be increased to 1 sec.

Pending

9 Reverse Zone enabled only for alarm not for trip. Mail dated 07.02.2018:

As per the recommendations of CEE RT & R & D, KPTCL, Zone-4 (reverse zone) is

enabled for trip also.

Complied

10 Zone-4 time delay is kept as 1.2 sec Mail dated 07.02.2018, 21.02.2018 & 21.07.2018 & 23.01.2019:


second.





Pending

11 Line length is confirmed as 65Kmtrs instead of 69Kmtrs. Mail dated 07.02.2018:

As per the recommendations of CEE RT & R & D, KPTCL, length of the protected line is

set to 67.6Km.

Complied

12 Hubli-1,2 & 3 Line

Feeders

220KV Protection Zone-4 time delay is kept as 1.2 sec Mail dated 07.02.2018, 21.02.2018 & 21.07.2018 & 23.01.2019:


second.





Pending

All Line Feeders 220KV Protection

Kodasali-1&2 and

Ambewadi-1&2

Line feeders

220KV Protection

Bidnal Line feeder 220KV Protection

22/95

Annexure-VI

Page 22 of 95

13 Distance protection's adopted resistive reach setting for Zone-1,2 & 3 is not matching with

the recommanded setting given by Tractebel based on Ramakrishna committee



Settings in all the feeders are made as per the recommendations of CEE RT & R & D,

KPTCL.

Complied


Zone-3 time delay is set as 800msec as recommended by CEE RT & R & D, KPTCL.

Complied

15 Zone 4 reach should be set to cover 50% of shortest line connected in Nagjhari SS ( existing



Settings recommended by CEE RT & R & D, KPTCL are such that reverse zone covers

20% of the protected line or 50% of the shortest reverse line impedence whichever is

less.

Complied

16 Resistive reach of reverse Zone is not kept identical with Zone-3 resisitive reach. Mail dated 07.02.2018, 21.02.2018 & 21.07.2018 & 23.01.2019:

Settings in all the feeders are made as per the recommendations of CEE RT & R & D,

KPTCL.


asked to keep resistive reach of Zone-3 and Zone-4 (reverse) identical.

Pending

17 Bus bar Protection 220KV Protection Bus bar protection main & check relay are connected to same CT core, 4 Cores are available. Mail dated 07.02.2018, 21.02.2018 & 21.07.2018:

Procurement of 5 core CT is under process.Time frame is requested for 2 yrs.


Procurement of 5 core CT is proposed to be taken up under PSDF-2. Approval from

Nodal agency is awaited. However, NIT issued. Time frame is requested for 2 yrs.

Pending

18 Hubli-3 and

Kodasali-1&2 Line

Feeders

220KV Protection Carrier Protection is not working in Hubli-3 and Kodasali-1&2 Line feeder. KPTCL informed

that due to CVT & Wave Trap problem carrier protection are not working, New CVT erection

& commissioning works are in progress & wiring is completed in PLCC panel. Will be

commissioned at the earliest.

Mail dated 07.02.2018, 21.02.2018 & 21.07.2018:

CVT's and wave traps are commissioned and the carrier protection is working.

Complied

19 All Line Feeder 220KV PLCC There is provision for one PLCC Channel (Protection & Speech) for each 220 kV double circuit

lines.


Provision available for both speech & protection for each line.

Complied

20 Bus Bar

sectionaliser

Breakers

220KV LBB Protection LBB protection is not provided for the sectionaliser breakers (Two Nos.) Mail dated 21.02.2018 & 21.07.2018:

Will be implemented in future.


asked to provide definite time-line for attending the remark.


Will be taken up alongwith SCADA proposal

Pending

21 All Line feeders

(Except Kodasali-

1&2 Line feeder)

220KV Protection Main-I & Main-II relays found to be of same type & make for all 220 KV Line feeders except

Kodasali-1&2 line feeders. KPCL informed that the same is replaced with in one month.


Main-II distance protection relays in all the lines are replaced with Schneider make

Micom P444 numerical distance protection relays.

Complied

22 General 220KV Control room Fire alarm/detection system is not provided in the 220KV control room. Mail dated 21.02.2018 & 21.02.2018:

Will be taken up during SCADA implimentation


Fire alarm/ detection system provided in 220KVcontrol room.

Complied

23 General 220KV Equipment Time Synchronisation is not working in the 220KV line feeders, due to GPS failure. KPCL

informed that the GPS equipment will be replaced within one month.


New GPS system is already commissioned and all the numerical relays are time

synchronized.

Complied

24 General - DC system It is observed that, even though two DC system is available in the generation plant, both the

sources are connected to common bus and single DC power supply distribution to 220KV SS

DC auxiliaries (Field equipments & Relay panels). The Measured DC Voltage (V) (At farthest

point of the yard):

DC Voltage:

+ve to -ve = 253.1V



Mail dated 07.02.2018 & 21.02.2018:

OEM has been approached for providing redundancy in already existing two separate

250 V DC sources.

Mail dated 21.07.2018 & 23.01.2019:

Two separate DC system will be provided during implimentation of SCADA by availing

PSDF fund.

Pending

25 General 415V ACDB It is observed that Only one Incoming power supply in 415V ACDB. Mail dated 07.02.2018, 21.02.2018 & 21.07.2018 & 23.01.2019:

Will be taken up shortly.

Pending

All Line Feeders 220KV Protection

23/95

Annexure-VI

Page 23 of 95

26 General 415V DG set Generation plant 415 V emergency DG set is utlised for 220KV SS emergency auxiliaries

during main source blackout. DG set start in Manual mode. Also, Manual changeover

arrangement only has been provided in the ACDB Main source and DG source.

Mail dated 07.02.2018 & 21.02.2018:

Procurement of AMF panel is under process.

Mail dated 21.07.2018 & 23.01.2019:

Procurement of new DG set along with AMF panel is under process.

Pending

27 General - 48 V DC system It is observed that even though two 48VDC sources are available in the generation plant,

both the sources are connected to common bus and single DC power supply distribution to

PLCC panel. No redundancy.

Mail dated 07.02.2018 & 21.02.2018:

OEM has been approached for providing redundancy in already existing two separate

48 V DC sources.


Work order has been placed for providing two separate 48V DC sources for PLCC

panel.


Work completed.

Complied

28 General - Equipment Most of the circuit breaker cubicles in 220KV feeders have not been provided with panel

lamp. Door switches were also not working properly.




Seven number of breakers replaced with new breakers along with panel lamps.

Remaining will be replaced by availing PSDF fund.


Seven number of breakers replaced with new breakers along with panel lamps.

Procurement of remaining breakers is proposed to be taken up under PSDF. Approval

from Nodal agency is awaited. NIT issued

Pending

29 General - Equipment It is observed that single earthing has been provided for most of the marshalling boxes and

few structures in switchyard. Also Door earthing was not provided in the most of the

marshalling boxes. The dummy gland holes in few marshalling boxes were not covered.


Double earthing provided for all MB's and structures.

Complied

30 General - Equipment The following 220KV Line feeders LA meters are not in working condition.

1.Ambewadi-2 (Y&B-Phase)

2.Hubli-1,2&3 (Y&B-Phase)

3.Ambewadi-1 (Y-Phase)

4.Bidnal (Y&B-Phase)




Completed.

Complied

31 General - Equipment Due to aging some of the MBs' door gaskets are worn out and panels rusted leading to

coal dust deposition and vermin ingress in 220KV S/S.It is advised to replace the MBs/

panels with IP 55/ IP6X panels as soon as possible.



Mail dated 21.07.2018 & 23.01.2019:

Will be replaced along with new breakers by availing PSDF fund.

Pending


Constituent)

3) 220 kV Sharavathy GS [30 - 31 October, 2017]


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1 Mail dated 07.02.2018 & 21.02.2018:

(i) Vegetation and weeding cleaned - Jelly spreading work will be taken up after

strengthening / modification works of the Station Earth mat at SGS.

(ii) Covering of cable trenches by checker plates/concrete blocks is under progress.

Dressing of routed cables done

(iii)Work is under progress, almost 70% of work is completed.

(iv)Door to Panel earthing made for all Marshalling boxes (wherever not provided) -

work completed

(v) Equipment labeling work is under progress.


i) Vegetation and weeding has been cleaned. The jelly spreading work at yard (ODY) is

completed.

ii) Covering of cable trenches by checker plates/concrete blocks completed. Dressing

of routed cables done.

iii) ---Completed.

iV) ---Completed.

V) Equipment labeling work is completed.

Complied

2 Mail dated 07.02.2018 & 21.02.2018:

Work of Re-enforcement of equipment supporting (RCC) structures is in progress.


Informed that the recommedations are complied.

Complied

3 Mail dated 07.02.2018:

The other bus can be used as suggested only when there is no maintenance on the

spare bus /isolators connected with it. Since there will be maintenance work on the

spare bus connected bus /isolators the suggested scheme cannot be used for safety

reasons.

Complied

4 Mail dated 07.02.2018:

The problem was rectified.


Presently Positive to earth is 123 Volts.

Negative to earth- (123) Volts.

Complied

5 Mail dated 07.02.2018 & 21.02.2018:

Letter written to EE(MRT), KPTCL vide letter No: EE(controls)J/RT/F10. Awaiting for

reply.


Informed that the recommedations are complied.

Complied

6 Mail dated 07.02.2018 & 21.02.2018:


reply.


i) & ii) Informed that the recommedations were complied.

Complied

7 Mail dated 07.02.2018 & 21.02.2018:


reply.

Mail dated 21.07.2018 & 23.01.2019:

Letter written to EE(MRT), KPTCL vide letter no :EE(Controls)J/RT/F10/

Waiting for their visit.

Pending

8 Mail dated 07.02.2018 & 21.02.2018:


reply.

Mail dated 21.07.2018 & 23.01.2019:

Letter written to EE(MRT),KPTCL vide letter no :EE(Controls)J/RT/F10/

Waiting for their visit.

Pending

It is observed that some of the existing gantry & equipment supporting (RCC) structures are in dilapidated state. Steps may be taken to reinforce

them suitably.

It is noted that even though the Bus-Configuration for Sharavathy GS has been designed for a full-fledged double-bus operation with four sections, it

is mostly run on single-bus operation with two sections with both the bus-couplers in OPEN condition and the other bus being used solely as a

transfer bus. Steps may be taken to using full-fledged Double Main-Bus system with four sections instead of the present Single Main-Bus with two

sections.

DC earth leakage is observed in both 250 V DC Sources. Steps shall be taken to rectify the same at the earliest.

Time settings and Reactive & Resistive reaches of Z2, Z3, and Z4 (reverse) of distance relays are observed to be not in line with Ramakrishna

Committee guidelines, which may be reviewed appropriately in consultation with KPTCL.

(i) In PSB settings, unblocking time delay for Z2, Z3 may be revised to 2 sec from the present 3 sec.

(ii) VT fuse fail time delay, which has been presently kept as 0.2 sec, may be suitably revised to 0.5 sec.

(i) Vegetation & weeding was observed in switchyard area. Steps may be taken to provide chemically treated PCC flooring, and then covering it with

suitable blue metal spreading in switchyard area. Steps to be taken to maintain proper upkeep of station by regularly undertaking cutting of weeds,

grass & unwanted vegetation growth in the switchyard area.

(ii) Routing of cables for termination in panels in the switchyard should be done systematically employing proper raisers/ trays. Further, cables &

cable trenches in the switchyard should be covered properly.

(iii) Double-earthing to be provided for all metallic structures in switchyard area.

(iv) Door-to-Panel earthing to be provided in various marshalling boxes, whereever not provided.

(v) Equipment labeling for proper phase-sequence may be provided.

Re-Trip feature to be provided for Breaker Failure Protection in Feeders and GT's.

Mode of Carrier-Aided-Scheme for Talaguppa line-3 (of 20 km) may be changed to Permissive Over Reach from the existing Permissive Under Reach.

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9 Mail dated 07.02.2018 & 21.02.2018 & 21.07.2018:

It has been enabled and checked at the time of commissioning.It will be enabled

immediately after completion of station Earth Mat strengthening works.


It will be enabled immediately after completion of station Earth Mat strengthening

works.

Pending

10 Mail dated 07.02.2018 & 21.02.2018:

It has been communicated to AEE(PLCC) KPTCL,Awaiting for reply.

Mail dated 21.07.2018 & 23.01.2019:

The card level redundancy is not possible with the existing PLCC Panels. Action will be

taken up after discussion with KPTCL.

Pending

11 Mail dated 07.02.2018 & 21.02.2018:

Proposal raised for replacement of exsisting D.G with new D.G having the auto mode

feature.

Mail dated 21.07.2018 & 23.01.2019:

Steps initiated for starting the D.G .in Auto Mode Procurement of D.G With New AMF

panel is under process.

Pending

12 Mail dated 07.02.2018 & 21.02.2018:

Protection part has been completed at common Auxiliary.Transformer and cabling to

be done.


Protection part has been completed at common Auxiliary. Transformer Procurement

and cabling to be procurement is under progress. Work will be completed during year

2018-19.


Protection part has been completed at common Auxiliary. Work order issued for

procurement of Transformer is under progress. Work will be completed during year

2019-20.

Pending

13 Mail dated 21.02.2018:

Measures are taken to maintain records.


Steps have been taken to measure station earth resistance and to carry out integrity

test of existing earth mat.


Completed.

Complied

14 Mail dated 21.02.2018:


Complied

15 Mail dated 07.02.2018 & 21.02.2018:

Calibration, interfacing with DCS, alarm setting implementation are in progress.

Mail dated 21.07.2018 & 23.01.2019:

Work is in progress through M/s.ABB Ltd., under Restoration works

Pending

16 Mail dated 07.02.2018 & 21.02.2018:

Action is initiated to procure all equipments.


Initiated for the purchase of testing / measuring instruments. Winding resistance

meter procurement is under tender stage.


Procurement initiated.

Pending

Presently, AC auxiliary supply is obtained from Station Aux.Transformers with DG set as back-up. It is also seen that works are under progress to

provide one external AC auxiliary supply (from MUSS, KPTCL, Jog). It is recommended to expedite providing external AC aux. supply.

Measurement of earth-resistance values for various earth-pits shall be undertaken periodically as per relevant standards, and records maintained

properly.

In some Units, leakage current indicators of Lightning Arresters on 220KV side are found to be faulty; the same shall be replaced/ rectified.

Vibration monitoring systems of Units with alarm settings to be commissioned fully.

The following equipment shall be purchased for maintenance of various switchyard equipment:

(i) Thermo-vision imaging camera to identify hot spots in yard equipments and transmission lines.

(ii) Dynamic Contact Resistance Meter for Breaker maintenance

(iii) Winding Resistance Meter

(iv) Earth-resitance measuring kit

It is observed that A/R for all 220 kV lines has been kept out of service due to pending earth-mat strengthening works. Steps shall be taken to keep

A/R in service at the earliest.

It is noted that even though two Channels per Circuit have been provided for PLCC, Card-level redundancy has not been provided for those channels.

Steps shall be taken to provide the same.

It is observed that DG-Set starting is being done manually. Steps shall be taken to provide DG-Set starting in auto-mode.

4) 400 kV Yermarus TPS [28-29 August, 2018]

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Constituent)

1 The recommendations w.r.t Distance Protection Zonal reaches & time settings has

been refered to M/s KPTCL and requested for the revised settings for early

implementations of the same.


Awaiting for the revised setttings from M/s KPTCL

Pending

2 Mail dated 23.01.2019:

With the available study report by M/s KPTCL, fault level of the station,

3-ph fault MVA- 14879.1 MVA

1-ph fault MVA- 6498.88 MVA ----Completed

Complied

3 The drop-off to pick-up ratio is 0.95 (fixed) as per the Distance protection relay

manual.


Drop-off to pick up ratio of 0.98 was ensured during relay testing for the Over

voltage(Stage-1) protection in the distance protection relays.- Completed

Complied

4 Mail dated 23.01.2019:

Stub Protection is kept enabled for both 400KV BPS-I &II lines. ----Completed

Complied

5 Mail dated 23.01.2019:

Completed

Complied

6 A/R logic is already implemented & functional as per the recommendation(1). However

time differentiated A/R shall be implemented in consultation with KPTCL. Matter

reffered to KPTCL..


Awaiting the reply from M/s KPTCL regarding the implementation of time differenctial

A/R for YTPS-BPS-I & II lines.

Pending

7 We have requested M/s KPTCL to funish setting details in order to enable the Load

Encorachment feature in distance protection relay(P443).


Awating for the revised setting from M/s KPTCL.

Pending

8 DEF protection implemented for 400KV BPS lines in P442 has been changed

from existing DT to IDMT char.


--- Completed.

Complied

9 PSL Logic has been implemented in order to block DEF protection as long as

Distance protection is active.


Completed

Complied

10 VT fuse fail/Blocking of distance protection & DEF with DT is enabled during

VT fuse fail condition.


Completed

Complied


The following variations observed w.r.t. Distance Protection Zonal reactance reaches & Time Settings for 400 kV BPS lines may be revised so as to

bring them in line with Ramakrishna Committee recommnedations:

Zone-2: Reactance reach --> 150% of Protected Line.

Time Setting --> 0.35 - 0.6 sec (this shall be kept more than the Zone-2 time setting at BPS end on 400 kV BPS-JSWEL line)

Zone-3: Time Setting --> 1 sec

Zone-4 (reverse): Reactance reach --> 50% of the Shortest Line connected at local bus.

Time Setting --> 0.5 sec

Actual Fault MVA level for 3-ph & 1-ph faults at 400 kV level of the station, calculated at periodic intervals, may be maintained with the station. The

present values of the same may be provided.

Implemented A/R logic may be reviewed as per the following logics decided in PCSC meetings for better reliability:

1. A/R is implemented and kept functional from Main – I [Main-II] only, but with feedback from Main-II [Main-I].

2. A/R is implemented and kept functional from both Main – I and Main-II.

In addtion to above, YTPS being a generator, going for time-differentiated A/R logic may also be explored.

Steps may be taken to ensure drop-off to pick-up ratio of 0.97 & above for the Over Voltage (Stage-I) Protection in the distance protection relays

employed for 400 kV BPS lines.

Stub Protection (typically 250% pickup & 50 msec) for 400 kV BPS lines may be kept enabled.

Under VT fuse fail condition, distance protection shall normally be kept blocked. However, upon detection of a fault (sensed by negative sequence

component), it may be ensured that blocking of distance protection gives rise to operation of its inherent Over-Current protection set with a suitable

definite time delay of say 1.2 sec

It shall be ensured that DEF protection for 400 kV BPS lines remains in blocked condition as long as Distance Protection is active, and becomes active

only when distance protection does not pickup.

Directional Earth Fault (DEF) Protection implemented for 400 kV BPS lines in P442 may be changed from the existing Def. Time characteristics to

IDMT characteristics.

Load Impedance Encorachment feature, which is presently kept disabled in P443, shall be enabled.

Auto-reclosure functionality implemented from P442 relay for Tie-CB's shall be kept disabled.

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11 Disturbance recorder (DR) & Event Logger (EL) has been configured to record

all the available mandated protections.


Completed

Complied

12 M/s BHEL-TBG is requested to provide automatic downloading of fault records

(DR's) from various protection relays to central PC. As it is in the scope of M/s

BHEL.


Automatic downloading of fault records (DR's) from various protection relays to

central PC is vailable & functional - Completed.

Complied

13 (i) It will be implemented in consultation with M/s KPTCL.

(ii) Implemented for all the Equipement breakers with PDR time delay as 0.5

sec.


Awaiting the reply from M/s KPTCL regarding the implementation of PD time

delay for Main & Tie CBs.

Pending

14 The OES (M/s BHEL) is requested to review the recommendations.


Awaiting the reply from OES.

Pending

15 The OES (M/s BHEL) is requested to review the recommendations.


Awaiting the reply from OES.

Pending

16 One more DC source will be provided with change over facility at relay panel.


Two independent DC sources are provided with changeover system in Busbar

protection panel - Completed

Complied

17 M/s BHEL-TBG is requested to rectify the ratio errors in CTs.


M/s BHEL-TBG yet to initiate the recification of errors in metering cores of CTs.

Pending

18 M/s BHEL-TBG is requested to take up the cutting of weeds, grass & unwanted

vegetation growth in the switchyard area.


Vagetation & weeding has been removed in switchyard area.- Completed

Complied

19 The covering of cable trenches with pre-cast slabs in the switchyard is under

progress. The cable gland sealing near circuit breakers has been completed.


The covering of cable trenches with pre-cast slabs in the switchyard is

completed - Completed

Complied

20 M/s RPCL will carry out the measurement of earth resistances of all the earth

pits on yearly basis and updated records will be maintained at site.


Completed.

Complied

Earth Fault Protection provided for Generator Transformers may be kept directional.

It is recommended to configure Disturbance Recorder (DR) and Event Logger (EL) of various protection relays to record all mandated protections.

It is observed that Pole Discrepancy time delay has not been set properly. It is recommended to keep PDR time delays as follows:

(i) For all line Main-CB's and Tie-CB's where Aut-Reclosure with priority has been employed with dead-times of 1 sec & 2 sec respectively, PDR time



kept as 0.5 sec.

Steps may be taken to provide automatic downloading of fault records (DR's) from various protection relays to central PC.

In Generator protections, the following may be reviewed suitably in consultation with their OEM:

(i) Under Frequency Protection (81U) Stages may be kept below the regional islanding frequency of 47.9 Hz.

(ii) Under Voltage Protection (27) may be provided with a suitable time delay of 100 - 500 msec

It is noted that even though duplicated Busbar protections have been provided in two separate panels, supply for the same has been provided from

one DC source. Steps may be taken provide from supply for two independent DC sources with a provision to effect changeover between them.

It is found that the various earth pit resistance values have not been measured after thier commissioning in 2015. It is recommended to carry out

measurement of earth-resistances of all earth pits on yearly basis, and keep updated records with the substation along with suitable earth-mat lay-

out diagrams. A copy of the same may also be furnished to SRPC Secretariat. It is also recommended to provide labeling for earth pit for proper

identification.

Certain cable trenches in the switchyard are found to be left open. Steps may be taken to cover them properly. Further cable gland sealing near

circuit breakers may also be properly done.

Vegetation & weeding was observed in switchyard area. Steps to be taken to maintain proper upkeep of station by regularly undertaking cutting of

weeds, grass & unwanted vegetation growth in the switchyard area.

It is observed that ratio errors of certain cores of CT's (esp. Metering cores) are on the higher side. Steps may be taken to rectify the same.

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21 It is requested to communication wing of KPTCL to maintain proper rated

voltage supply(48V) to PLCC system.

Pending

22 It will be coordinated with communication wing of KPTCL to measure & record

the db-level measurements of various Tx and Rx signals of all PLCC channels

on periodical basis.


Completed

Complied


Equipment/ System

auditated


Constituent)

1 Zone-4 time delay is kept as 1 sec. Mail dated 30.01.2018:

Zone-4time delay setting is revised to 0.5 sec

Complied

2 VT supervision time delay is kept as 1 sec. Mail dated 30.01.2018:

VT supervision time delay kept as 5 sec.

Complied

3 Auto-Recloser was kept off. NPCIL Kaiga has raised issues for enabling Auto-Recloser for

these lines.


Auto Reclosure is enabled and it is in service

Complied

4 Narendra 1 & 2 400 kv Protection Panel

Main-I relay

STUB time delay is kept as 100 msec Mail dated 30.01.2018:

400kV Narendra-1 &2 bays at Guttur belongs to Power Grid.Relay settings of these

bays are maintained by Power Grid.


Attended. STUB protection settings revised as per recommendations

Complied

5 JSWEL 400 kV PLCC Observed that Speech panel is out of service. KPTCL is informed restored by within two

months


Speech channel is incorporated in PLCC Protection Panel

Complied

6 Protection Panel

Main-I relay

Reverse zone is not available Mail dated 30.01.2018:

ABB make static type Main-I relay is replaced by numerical distance relay (ALSTOM

make ,P442 type) under R&U project.Reverse zone protection is provided

Complied

7 Protection Panel

Main-II relay

Carrier Protection was kept off Mail dated 30.01.2018:

Carrier protection is restored

Complied

8 Yard Found that No wave Trap is available in this line Mail dated 30.01.2018:

Wave trap is provided

Complied

9 Protection Panel

Main-II relay

DEF function was found off. Mail dated 30.01.2018:

DEF proteection is enabled

Complied

10 Yard Found that one wave Trap is available in this line. Mail dated 30.01.2018:

Work of providing one more wavetrap is included under R&U project.


The work is included under R&U. Supply of wave trap is awaited. Wave trap is to be

supplied.


Two no.s of wave traps are provided in Chitradurga line for providing Ph-Ph couplig

arrangement.

Complied

11 Haveri-1 220 kV Isolator Isolator was not working properly the same has been bypassed.KPTCL informed the same

would be restored with in one month.


Faulty isolator has been replaced

Complied

KPTCL

1) 400/ 220 kV Guttur SS [4-6 May, 2016]

KAIGA-1 400 kV Protection Panel

Main-I relay

Chitradurga 220 kV

Davangaere-2 220 kV

It is recommended to keep records of db-level measurements of various Tx and Rx signals of all PLCC channels employed for all feeders mesured at

periodic intervals (say bi-monthly) with the substation.

It is noted that PLCC supply voltages from the two DC sources are on the higher side. Suitable action may be taken to bring them to therir respective

rated voltages of 48 V.

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12 Davangaree 1, 2 &

3

220 kv PLCC No separate PLCC Protection panel available for all these 3 lines and observed that no

redundant card available.


Carrier protection is availabe for Main-1 relays of all three lines.One more PLCC panel

will be provided during retrofitting of Main-2 scheme.


Carrier protection is availabe for Main-1 relays of all three lines.Action is taken to

provide One more PLCC panel at Guttur end.


Wave traps,Coupling Units and CVTs required for both the ends have been procured

under R&U project. PLCC Cabinets along with Protection Coupler have been arranged.

After comissioning of ODY equipments carrier protection will be commissioned for all

three lines independently.

Pending

13 Neelagunda 220 kV Yard Found that B phase wave trap is not connected with Line.KPTCL informed the same would be

restored with in one month.


Wave trap is connected and normaly is restored.

Complied

14 Protection panel Over Load function was not available. Mail dated 30.01.2018:

Over load protection is provided.

Complied

15 ICT Oil seepage was observed. Mail dated 30.01.2018:

Oil seepage arrested

Complied

16 Bus coupler 220 kV Isolator Found that isolator misalignment in the arcing contacts. KPTCL informed the same would be

be attended with in the one month


Misalignment of arcing contacts rectified

Complied

17 Beernahalli-1 400 kV Line reactor Observed DC Voltage (203.6 V) in Isolator marshalling Box. Mail dated 30.01.2018:

Attended. Measured DC Voltage is 218 V in Isolator marshalling Box.

Complied

18 Bus Reactor 400 kV Protection Panel 5th Harmonic setting is kept as 35% in differential relay. Mail dated 30.01.2018:

5th Harmonic setting is changed to 25% in differential relay.

Complied

19 All 400 kV Lines Auto Reclouser enabled in both Main -1 & 2 of all 400 Kv lines (Expect Kaiga 1 &2). KPTCL

informed presently using inbuilt Auto-Reclouser in Distance relay itself.


Auto Reclosure is enabled in all the 400kV lines. Built in auto recloser feature is used

Complied

20 Auto Recloser reclaim time delay is kept as 20s. Mail dated 30.01.2018:

Auto Recloser reclaim time delay isrevised to 25 Sec

Complied

21 Zone 4 time delay has been is kept as 1.0 sec except Narendra-1-2 line. Mail dated 30.01.2018:

Zone-4 time delay setting is revised to 0.5 sec

Complied

22 Zone 4 reach setting should be set to cover 50% of shortest line. Mail dated 30.01.2018:

As per KPTCL practice, Zone-4 reach is set to cover 20% of the protected line or

50% of shortest line reverse whichever is lower. Z4 reach setting adopted at Guttur is

in order

Complied

23 Overvoltage Protection Stage-2 is kept as instantaneous. Mail dated 30.01.2018:

Over voltage function stage -2 time delay set as 100ms

Complied

24 All 220 kV Lines Auto Recloser is not available in all 220 kV Lines Mail dated 30.01.2018:

AR will be enabled during retrofitting of Main-2 distance scheme under R&U works


AR Scheme tesing is done for all lines at Guttur end during retrofitting of Main-2

distance scheme under R&U works. Actiion will be taken to enable AR once M-II

retrofitting is completed at remote end sub stations.


AR Scheme tesing is done for all lines at Guttur end during retrofitting of Main-2

distance scheme under R&U works. Actiion will be taken to enable AR once M-II

retrofitting is completed at remote end sub stations

Pending

25 Over voltage function is enabled all 220 kV lines. Mail dated 30.01.2018:

Over voltage functionis disabled in all 220kV lines

Complied

ICT-1 & 2 400/

220 kV

30/95

Annexure-VI

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26 No redundant backup distance protection is available in all 200 kV Lines (Except Chitrdurga

and Divanagree-2)


Main2 distance protecion is being provided under R&U project. Required relays are

already supplied to the site.


Main-2 distance protection is provided to all 220kV lines under R&U.

Complied

27 Observed that No redundant DC supply in PLCC panel Mail dated 30.01.2018:

Two set of Batteries and Battery Chargers are available.

Complied

28 All 400 & 220 kV

Lines

All Isolator were working locally electrical and Bypassed (Removed) electrical interlocks

between Circuit Breaker and Isolator.

Mail dated 30.01.2018 & 31.07.2018:

Action will be taken to provide electrical interlock between CB and isolator in all bays


Action is being taken to provide electrical interlock between CB and isolator in all bays

Pending

29 All 400 & 220 kV

Lines

Fire Fighting is not available in Control Room, Protection Panel Room & line reactor Yard.

KPTCL informed that the same would be installed within six months.


Fire Fighting equipments are available in Control Room and Protection Panel Room.

Complied

30 Found that redundant Auxiliary Supply is not available Mail dated 30.01.2018:

Two auxillary transformers (1 MVA each ) fed from separate feeders from different

incomers is provided at Guttur

Complied

31 No specific changeover interlock between Normal supply to Emergency Supply (DG set) Mail dated 30.01.2018:

Action will be taken to provide interlock during change over from normal to

emergency supply.


Interlock between Normal supply to Emergency Supply (DG set) is provided

Complied

32 Auto changeover facility is not available. Mail dated 30.01.2018:

Action will be taken to provide auto change over facility.


In KPTCL system , no LT circuit breaker available for DG set supply. Onnly switch has

been provided.


In KPTCL system , no LT circuit breaker available for DG set supply. Onnly switch has

been provided. Action will be taken to provide auto change over facility.


In KPTCL system , no LT circuit breaker available for DG set supply. Only switch has

been provided.

The issue was discussed in PCSCM-81 held on 24.01.2019. KPTCL was asked to take

steps to comply with the recommendation.

Pending

33 Walkie-talkie is not available for communication between switchyard and control room. Mail dated 30.01.2018:

Dedicated mobile phones are available.


In KPTCL sysem, dedicated mobile phones are provided in the control room. As

discussed during 76th PCSC meeting during review of Protection Audit

Recommendations, action will be taken to provide Walkie-talkie to 400kV Sub Stations


Action has been taken to provide Walkie-talkie to all 400kV Voltage Class Sub Stations

in KPTCL

Pending

34 In some of the Marshalling boxes, single point earthing is done. Mail dated 30.01.2018:

Action will be taken to provide one more earthing.


Action is taken to provide one more earthing. Procurement of required materials is

under progress.


The work will be covered under proposed R&M Works

Pending

31/95

Annexure-VI

Page 31 of 95

35 CT/CVT Star grounded done in filed (Expect Kaiga 1 &2) and bus bar protection done in

relay panel.KPTCL informed earthing for Kaiga 1 & 2 to be done filed.


Attended. Iall neutral earthing is done at Switchyard.

Complied

36 Most of the BMK's, CB/Isolator MB & gland plates are very old & corrosion, almost replace

condition. Gland plate holes are open in the most of the MB. KPTCL informed the same

would be attended during R&M

Mail dated 30.01.2018 & 31.07.2018:

R&M scope is yet to be finalised


The work will be covered under proposed R&M Works.

Pending

37 Few of the MB is door earthing was not done. Mail dated 30.01.2018:

Attended

Complied

38 GPS is not available for Time Synchronisation Mail dated 30.01.2018:

GPS time synchronisation device has been supplied under R&U, erection and

commissioning works will be taken up shortly.


GPS time synchronisation device is provided under R&U works

Complied

39 Ventilation is not sufficient for control & Protection and Battery rooms. Mail dated 30.01.2018 & 31.07.2018:

Exhaust fans are provided in battery room. AC is being provided to in Control Room.

Complied

40 Salt formation found in Battery Mail dated 30.01.2018:

Salt formation on the battery terminals have been removed. Also, one battery set has

been replaced by new under R&U work. Replacement ofsecond set of battery bank is

under progess


Both the battery sets have been replaced by new battery sets under R&U work.

Complied

41 Main-I & Main-II relays found to be of same type & make for some 400 kV S/S. KPTCL

informed that the same would be attended during R&U .


M-II relays will be replaced by Seimens make numerical distance relays. Required

relays have been supplied by M/s GE under R&U. Retrofitting work will be taken up

shortly.


M-II relays replaced by Seimens make numerical distance relays in 4 no.s of 400kV

lines bays. Replacement of M-II relay of remaining two bays is included in the

extended scope of R&U.


M-II relays replaced by Seimens make numerical distance relays. ---Completed

Complied

42 DC supervision relay is not available in Control Panel. Mail dated 30.01.2018:

DC supervision relay is available in the relay Panel & DC fail annunciation has been

provided in the control panel.

Complied

43 Measured DC Voltage (V):

DC-1 DC-2

+ to - : 232.2 222

+ to E : 143 132

- to E : 89.1 90


Measured DC Voltage (V):

DC-1 DC-2

+ to - : 239.5 236

+ to E : 121.3 120.2

- to E : 117.2 115.4

Complied


Equipment/ System

auditated


Constituent)

2) 400/ 220 kV Nelamangala SS [8–10 February, 2016]

32/95

Annexure-VI

Page 32 of 95

1 220kV

and

400kV

Control and

Protection Panels

For 400 KV Busbar protection, one main Bus bar protection scheme for each Bus 1 & Bus 2

available and Check Zone protection is not available because of static type relay. Redundant

Bus bar protection or Check zone shall be considerd.


The work of providing Main-1 and Main-2 Bus Bar protection for 400kV buses is

included under R&U project awarded to M/s GE T&D India Ltd.. Supply of new BBP

panels is expected during February 2018.


Main -1 and Main-2 BBP will be commissioned before end of December 2018.


The work of providing Main-1 and Main-2 Bus Bar protection for 400kV buses is

included under R&U project awarded to M/s GE T&D India Ltd. Materials for Main 1 & 2

Bus Bar Protection Supplied. The work is to be taken up by the firm.


Providing the additional Main 2 Bus Bar Protection (Alstom GE T&D) make,

P741/P743 Numerical Distributed type Low impedance with facility of check bus bar

protectionis taken up under R&U Project, required materials have been supplied.M/s

GE has started the work and presently completed Scheme preparation Cable Schedule

preperation. Modification is to be made for separate CT core (available but wiring

requires to be modified). New wiring is to be made for Breaker status and bus isolators

status shall be wired.For 400 kV Gooty, 400kV Bidadi line 1 & 2 separate CT core is to

be laid from CT MB to BB panel. Shut down is to be arranged. Main-2 BBP is

expected to be put in to service beore end of March 2019.

Pending

2 BFR (LBB) trips and BB protection trip are properly integrated in Trip Bus (96). Mail dated 30.01.2018:

In present conditon LBB trip is extended to BB realy thorugh trip bus sysem

Complied

3 Main 1 & Main 2 relay make and type (Siemens 7SA522) are same in 400kV Hassan, Hiriyur-

1 and Hoody-1 lines.


Main-1 and Main-2 relays of same make(Seimens) but different of different type.

Main-1 relay is 7SA522 type and main-2 is 7SA513 type.

Complied

4 In Hiriyur-1 line reactor group 2 protection relay (7SA 5101)-Backup impedance relay is not

in service.


Procurement of of New Back up Impedence realy is under process.


New Back up Impedence realy commissioned on 01/06/2018.

Complied

5 For 400kV bus bar protection panel, 2 DC sources are available with selector switch only.

Automatic changeover is not provided. KPTCL informed that the same will be implemented.


This observation will be implemented while commissioning of new 400 kV Bus bar

protection system.



protection system .



protection system

Pending

6 Auto-reclose feature is not enabled for 220kV lines. Mail dated 30.01.2018 & 31.07.2018:

AR scheme testing is completed at Nelamangala end during M-II retrofittng work. M-II

retrofitting is pending with remote end sub stations.Upon completion of M-II

retrofitting work at remote end, AR will be enabled.


Auto Reclosure is put in to service for DB Pura 1 &2 lines and Dobaspet lines. For

remaining lines M-II retrofitting work is to be completed at remote ends.

Pending

33/95

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7 220kV

and

400kV

Relay Setting Zone setting & Resistive reach setting for distance protection are found to be different from

the recommanded setting given by Tractebel based on Ramakrishna committee



Zone reach & resistive reach settings are in line with the protecion practice followed in

KPTCL. Other recommendations regarding Z4 timing, load angle, stub protection will

be adopted.



KPTCL. Other recommendations regarding Z4 timing, load angle will be adopted.



KPTCL. Other recommendations regarding Z4 timing, load angle,stub protection are

attended.

Pending

8 For all 400 kV lines, stub protection current level and time delay kept as 150% IB and 300

ms against recommended settings of current level of 250% IB and time delay of 50 msec.


Stub protection settings will be revised as per the recommendations.


Stub protection setting is revised as per the recommendations

Complied

9 For 400 kV Hiriyur line-2 and Hoody line-2 of model 7SA513 (Main-II), the relay has the

provision to provide only 3 Zones for distance scheme. Reverse zone is available in Main-1

and not present in Main-II.


Reverse zone setting is provided in the M-I relay.

Complied

10 400kV lines (Mysore 1&2,Bidadi 1&2 and Gooty) Zone 2 time is setting as 500ms instead of

350ms.


These bays and its relay settings are maintained by PGCIL. To be attended by PGCIL

(SR-II)


Relay settings are maintained by Power Grid, to be confirmed by Power Grid


Relay settings are maintained by PGCIL.

The issue was discussed in PCSCM-81 held on 24.01.2019. OGCIL (SR-II)

had confirmed implementing the gvien recommendation.

---Completed

Complied

11 Load encroachment feature was not available for 400kV Neelamangala-Talaguppa line.

KPTCL informed that the resistive reach of zone-3 is limited to less than the Minimum load

resistance with a margin of 20%. Also load encroachemnt feature will be enabled in Main-1

relay after consultion with OEM.


Resistive reach of zone-3 is limited to less than the Minimum load resistance with a

margin of 20%.



margin of 20%. 20% margin between the main load resistance and resistive reach of

Zone-3 of the distance relayhas been maintained subject to maximum value as above,

each zone will be provided with maximum resistive reach in proportion to its reactive

reach

Complied

12 DEF is available in one main distance relay in 220kV and 400kV lines. DEF will not be

available in the event of outage of Main distance relay in which function is enabled.


Action will be taken to enable DEF protection in both M-I and M-II relays.


DEF protectionis enabled in both M-I and M-II relays.

Complied

13 In Mysore-1&2, Bidadi-1&2, lines over-voltage stg-1 was enabled in Main-1 distance relay

and over-voltage stage-2 was provided through a stand alone relay. In the event of failure or

non-availability of Main- distance relay only over-voltage stage-2 protection will be available.


These bays belong to Power Grid. To be attended by PGCIL (SR-II).


Bay belongs to Power Grid, will be persued with PowerGrid




Completed

Complied

34/95

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14 In 220kV feeders few trippings were observed due to power swing trip feature provided in

Siemens Distance relay (7SA522). It was also observed that there is no provision for blocking

time delay for PSB setting in distance relay provided for 220kV lines. KPTCL informed that

the same will be taken up with OEM to ascertain the correct reason for tripping and

accordingly modify the PSB setting.


Power Swing trip has been disabled in all bays.

Complied

15 220kV

and

400kV

Field

Equipments,ICTs &

Reactors

Lot of Grasses and other weeds are found over the Gravels in the 220kV and 400kV

yard.Weed control by chemical spraying is under process.


Switchyard is kept Clean free from Weeds Periodically

Complied

16 In ICT -3 bay, cable PVC conduit are not sealed and exposed to atmosphere . Mail dated 30.01.2018:

Action taken to fill the openings of PVC pipes by Bitumen compound

Complied

17 Oil leakage was observed in 400 kV Hiriyur-1line reactor Y-Phase bushing turret. Mail dated 30.01.2018:

Oil leakage is arrested

Complied

18 Most of the ICT & reactor conservator tank breather silicagel was in pink colour.Necessary

moisture control action has to be done.


Silicagel is replaced.

Complied

19 SF6 leakage was frequently observed in 400kV Hassan-40752 (Nel Make) and 220kV Nitttur-

21852 (Nel make) line breakers. Necessary action has to be taken.


Attended.

Complied

20 In some 220kV/ 400 kV bays, LA surge counters are not in working condition. Mail dated 30.01.2018:

Faulty surge counters have been replaced.

Complied

21 For 400kV Gooty line reactor, NGR is not provided. Mail dated 30.01.2018:

Bay belongs to PGCIL (SR-II). To be attended by PGCIL (SR-II).





Review Meeting held alongside PCSCM-81 on 24.01.2019:

PGCIL (SR-2) informed that NGR is not required as per their system Studies.

--- Completed

Complied

22 Emulsifier system for fire fighting of ICT/ LR is not in healthy condition. KPTCL informed that

Nitrogen injection system will be provided.


All the ICT's and Line Reactors are provided with CTR make Nitrogen Injection Fire

Prevention System

Complied

23 Walky takie is not available for communication between switchyard and control room. Mail dated 30.01.2018:

Dedicated mobile phones are available.


In KPTCL sysem, dedicated mobile phones are provided in the control room. As

discussed during 76th PCSC meeting during review of Protection Audit

Recommendations, will be taken to provide Walkie-talkie to 400kV Sub Stations



in KPTCL

Pending

24 Smoke detection system is not in heathy condition for control room building. Mail dated 30.01.2018:

Action is being taken to renovate the Smoke detection System.


The work is awarded to M/s Universal Engineers, expected to be completed before end

of August 2018


Attended.

Complied

35/95

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25 AC Distribution Auto Changeover is not available in ACDB for 415V Auxiliary supply 1 & 2 and DG set. AMF

panel in DG set is not in healthy condition. Supply Change over operation is carried out

manually. Remotely switching ON of DG is not available from ACDB


Action is being taken to provide auto change over of DG system incase of Auxiliary

supply failure


The work is awarded, expected to be commissioned before end of August 2018


Auto statrt of DG set is made enabled on failure of Auxillary supply, while DG breaker

has to be closed manually as facility of auto close is not avilable in the DG breaker.

Pending

26 It was observed that one 11kV feeder is available for auxilliary supply of station. It was

informed by KPTCL that 2nd 11kV auxilliary supply will be made available after

commissioning of 66/11kV Sondekoppa substation. It was observed that there is no

automatic chaneover available for auxilliary supply changeover.


Matter Persued with BESCOM officials and separate 11 kV UG cable from 66kV

Sondekoppa Sub station to 400 kV RS Nelamangala is laid. 66kV Sondekoppa SS is yet

to be commissioned.


Matter Persued with BESCOM officials and separate 11 kV UG cable from 66kV

Nelamangala Sub station to 400 kV RS Nelamangala is laid, the same is to be

commissioned.Also, back up auxilliaryfeeder is taken from 66kV Sondekoppa Sub

Station. Commissioning of Sondekoppa SS is delayed due to RoW problem.


Matter Pursued with BESCOM officials and separate 11 kV UG cable from 66kV

Sondekoppa Sub station to 400 kV RS Nelamangala is laid. 66kV Sondekoppa Sub

Station is to be commissioned.

Pending

27 DC Distribution 2nos, 220 V DC battery banks with two Battery chargers (one is main and another is

standby). main Battery charger feeds both DCDB-1 & 2 with buscoupler closed.When Main

fails standby charger will be 'ON' manually.

Mail dated 30.01.2018 & 31.07.2018:

M/s Caldyne Make Automatic Float and Boost Charger is provided, with facility of

keeping one in float and another in Trickle maode. Both the Charger could not be

taken on Float simulatneaous.




taken on Float simulatneaous with existing setup.

Pending

28 48 V DC system is also redundant similar to 220 V DC system. Mail dated 30.01.2018:

Loads on both the chargers have been bifurcated.

Complied

29 Protection DC-1&2 (220V) for 220kV and 400kV bays was observed to be linked at DCDB

through 220V bus coupler and same was being extended to protection relays.

Mail dated 30.01.2018 & 31.07.2018:



taken on Float simulatneaous.




taken on Float simulatneaous with existing setup.

Pending

30 48V DC-1&2 for PLCC was observed to be linked at DCDB through 48V bus coupler and same

was being extended to PLCC panels.


Loads on both the chragers have been bifurcated

Complied

31 Communication

system

The System for Auto downloading of disturbance recorders from the relays is not provided,

however manual downloading is done as and when fault occurred.

Mail dated 30.01.2018 & 31.07.2018:

Remote DR/EL collection system supplied under R&U project will be commissioned

shortly.


The work is under progress by M/Kalkitech under R&U project.

Pending

36/95

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32 SEL , ABB REL 521,EPAC 3000,Reyrolle omegha type relays of 400KV Mysore 1 & 2, bidadi 1

& 2 lines and Busbar protection relays are not time synchronised with GPS.


The existing CRPs of 400kV Mysore-1 &2,Bidadi-1 &2 and Gooty bays will be replaced

by new CRPs mounted in KIOSKs along with providng 61850 based SAS & GPS time

synchronisation. The work is entrusted to M/s Shree Electricals Limited.


The time synchronisation of the existing relays can be arranged by using the existing

GPS which is in service. Coordination from PGCILis required since bay belongs to

Power Grid.


The existing CRPs of 400kV Mysore-1 &2,Bidadi-1 &2 and Gooty bays will be replaced

by new CRPs mounted in KIOSKs along with providng 61850 based SAS & GPS time

synchronisation. The work is entrusted to M/s Shree Electricals Limited. Presently

procurement of control cables required to take up the work odf one bay is under

procurement stage. Cable schedule has been sent to Power Grid for approval.

Pending

33 Redundancy is not maintained in Fibre optic equipment. Commisioning of second set of FOTE

is under progress.

Mail dated 30.01.2018 & 31.07.2018:

The work is entrusted to M/s Shreem Electric Limited.


The work will be attended under R&M scope awarded to Shreem Electricals.

Pending

34 One no. PLCC protection coupler availbale for 220kV lines. Mail dated 30.01.2018:

Only One PLCC protection coupler is provided as per the protection practice followed

in KPTCL

Complied

35 General DR is not available for 400kV bus bar protection. DR of 220kV and 400kV lines not getting

triggered with operation of LBB/ Bus bar protection. 220kV bus bar relay not time

synchronized with GPS. KPTCL informed that this will be synchronized.


For 400kV Buses, Main-1 and Main-2 Numerical BBP is being provided under R&U

project wherein DR/EL will be available. Supply of new BBP panels expected during

February 2018.


Main -1 and Main-2 BBP will be commissioned before end of December 2018.


Main -1 and Main-2 BBP will be commissioned before end of December 2018


Numerical M-II BBP will be commissioned under R&U works, expected to be completed

before end of March 2019.

Pending


Constituent)

1 Mail dated 23.01.2019:

Settings adopted are in line with protection philosophy followed in KPTCL and found to be

working satisfactory. No Overlapped trippings due to zone reaches observed in these lines. Zone-

3 time setting of 0.8 seconds is adopted for all lines in KPTCL. Zone-4 reverse reach will be

reviewed considering the shortest line connectted to the local bus.

Pending

2 Mail dated 23.01.2019:


margin of 20%. 20% margin between the main load resistance and resistive

reach of Zone-3 of the distance relay has been maintained subject to maximum value

as above,each zone will be provided with maximum resistive reach in proportion to its

reactive reach. However action will be taken to enable Load Encrochment feature

during detailed testing to be conducted by OEM M/s GE.

Pending

3 Mail dated 23.01.2019:

Attended. Stub protection tiiming is revised to 50msec

Complied

The following variations observed w.r.t. Distance Protection Zonal reactance reaches & Time Settings for all 400 kV feeders may be revised so as to

bring them in line with Ramakrishna Committee recommnedations:

Zone-2: Reactance reach --> 150% of Protected Line in case of D/C lines. (In case of encorachment into next voltage level, necessary

discrimination may be obtained by proper time-coordination)

Time Setting --> 0.35 - 0.5 sec


Zone-4 (reverse): Reactance reach --> 50% of the Shortest Line connected at local bus

Load Impedance Encorachment feature, which is kept disabled in P444 relay, may be enabled.

3) 400 kV Bellary PS [27 August, 2018]

Remarks/ Deficiences/Nonconformity observed

Stub Protection Timing, which is presently kept as 100 msec, may be suitably revised to 50 msec.

37/95

Annexure-VI

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4 Mail dated 23.01.2019:

Over current protection incorporated with additional logic will operate for high resistive phase

to phase faults and will not enchroach with line loadings. Hence it is requested to drop this

observation.

The issue was discussed in PCSCM-81 held on 24.01.2019. It was noted that the

provided O/C protection would become enabled only when DPR does not pick-up.

Hence PCSC forum agreed to drop the Remark.

Dropped

5 Mail dated 23.01.2019:

The confiiguration of relays and SAS related issues noticed during recent trippings/ protection

audit have been taken up with the OEM M/s GE. M/s GE will be depute their engineers during

First week of February 2019. Shut downs have to be availed for detailed testing.

Pending

6 Mail dated 23.01.2019:

Logic/ settings for enabling non directional over current protection which is to be activated in

the event of VT Fuse fail has been communicated to the fielsd officials. Adoption of the same

will be ensured during detailed testing to be conducted by OEM.

Pending

7 Mail dated 23.01.2019:

Attended. LBB retrip timig is revised to 100msec

Complied

8 Mail dated 23.01.2019:



First week of February 2019.

Pending

9 Mail dated 23.01.2019:



First week of February 2019.

Pending

10 Mail dated 23.01.2019:

Attended by OEM M/s GE Ltd on 29.08.2018

Complied

11 Mail dated 23.01.2019:

Attended by TCD wing

Complied

12 Mail dated 23.01.2019:

Attended. PDR time settings revised as follows: Main Circuit Breakers : 2 seconds; Tie Circuit

Breakers :2.5 Seconds and Bus Reactor Breakers: 0.5 seconds

Complied

13 Mail dated 23.01.2019:



First week of February 2019. Shut downs have to be availed for detailed testing.

Pending

Default Protection Settings kept in various protection relays may be validated for correctness of operation.

In P444 relays, PSL logic employed for issuing instantaneous 3-ph trip upon detection of Zone-2 Start/ Zone-3 Start for Ph-Ph faults shall be disabled.

Time setting of Re-Trip feature of LBB protection may be revised to 100 ms from the present 50 ms.

In addition to blocking of distance protection under VT fuse-fail conditions, it shall be ensured that upon detection of a fault (sensed by negative

sequence component), blocking of distance protection gives rise to operation of its inherent Over-Current protection with a suitable definite time

delay of (say) 1.2 sec.

In 400 kV JSWEL lines, where POR scheme is used, current reversal guard logic may be enabled to avoid unwarranted trippings.

Over Current Protection, which is presently kept enabled in 400 kV feeders, shall be disabled.


It is observed that Pole Discrepancy time delay has not been set uniformly. It is recommended to keep PDR time delays as follows:




kept as 0.5 sec.

The PLCC Speech Channels for Pavagada lines are found to be not kept in service, which may be restored.

It is noted that the PLCC Protection Channel-1 of 400 kV JSW line-4 was unhealhty. It is recommended to take steps to restore it to normalcy. It is

also recommended to keep records of db-level measurements of various Tx and Rx signals of all PLCC channels employed for all feeders mesured at

periodic intervals (say bi-monthly) with the substation.

38/95

Annexure-VI

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14 Mail dated 23.01.2019:

The issue is taken up with the management.

Pending

15 Mail dated 23.01.2019:

The issue is being persued with GESCOM officials for arranging alternate AC auxilliary supply

from 110kV Torangallu Sub Station.

Pending

16 Mail dated 23.01.2019:

Instructions have been given to field officers to keep in Auto mode.

Pending

17 Mail dated 23.01.2019:

Measurement of earth pit resistance has been completed recently and results are found to be

satisfactory. Test Reports will be furnished to SRPC once received from field.

Pending

18 Mail dated 23.01.2019:

Action is being taken to comply the issue.

Pending

19 Mail dated 23.01.2019:


in KPTCL

Pending

20 Mail dated 23.01.2019:

Concered RT Batch is equipped with necessary testing equipments . Also action is being taken to

procure new test kits such as CT/PTanalyser, Winding Resistance test kit etc is being processed

by CEE,T&P.

PendingSteps may be taken to provide the following test-kits to concerned RT Sub-division for proper maintenance of 400 kV Ballari PS:

1. Digital Low Range Tong Tester

2. Energey Meter Testing Kit

3. Winding Resistance Measurement Test Kit

4. Insulation Resistance test-kit with induction compensator

5. Numerical relay test kit

6. On-line DC earth fault locator

7. SF6 Gas leakage detector

8. CT and PT testing kit/ analyzer

It is noted that the furnished values of earth-pits resistance are within the mandated limits. However, since they were meaured more than an year

ago (January, 2017), it is recommended to carry out measurement of earth-resistances of all earth pits on yearly basis, and keep updated records

with the substation along with suitable earth-mat lay-out diagrams. A copy of the same may also be furnished to SRPC Secretariat.

It is observed that DG-Set starting and supply changeover among AC supplies & DG set are being done manually. The same may be kept in auto

mode.

It is seen that the station is having only one source of AC auxiliary supply. It is recommended to provide redundant AC auxiliary supply from another

suitable substation for better reliability.

In view of the short length (10 km) of 400 kV BPS - JSWEL lines, line differential protection may be provided as both Main-I and Main-II as per the

following logic:

“Line differential protection is to be provided as both Main-I & Main-II protection with distance protection as backup (built-in feature of Main relay or

standalone relay). The Zone-1 of such back-up distance protection would normally be in disabled condition, and would get automatically activated/

enabled in the event of communication link failure (i.e., when line differential protection goes off) to offer primary protection. The Zone-2 & Zone-3 &

Zone-4 (reverse) of the back-up distance protection will always be kept enabled to offer back-up protection".

It is observed that cable trenches near circuit breakers are found to be kept open, which may be covered properly.


39/95

Annexure-VI

Page 39 of 95


Equipment/ System

auditated


Constituent)

1 Bus 220KV System Presently two buses are available with a bus coupler breaker for 220kV switchyard. Bus bar

protection is available for both the 220kV buses and bus-bar protection is available with two

main zone and one check zone. With the present bus arrangement it is not possible to

interchange feeders between both the buses and shutdown has to be taken in the event of

any maintenance on the line breaker. Provision of additional 220kV bus (transfer bus) which

is already proposed in earlier protection audit will rectify the above issues and improve the

reliability of Edamon station. KSEB has informed that Hybrid switch gear/out door GIS is

being planned for SBEM 2&3, EMKD,EMEP and Transformer 1 & 2 Bays and bus coupler for

accommodating the additional 220kV bus. The work is scheduled to be completed by Dec

2016.


3 Hydrid units are erected commissioned namely SBEM#2 & 3 and Transformer bay

#1. Hybrid Bus coupler errected and will be commissioned subject to line permit

availability. The works on balance namely EMEP, EMKD and Transformer #1 are

under progress and scheduled to be commisioned by March 2018.


work completed

Complied

2 Bus 220KV Protection Single CT core has been used for main and check zone is derived from same core. KSEB had

informed that the bus bar protection would be replaced during provision of additional 220kV

bus. It is proposed to use separate cores for main and check zone and also to have a

redundancy for bus-bar protection relay for each Bus. A redundant scheme for Bus

protection to be included.


Seperate CT cores will be used for Main 1 and Main 2 relays of newly proposed bus

bar protection. Zone trip of Main 1relay + Check zone of Main 2 relay and Zone trip of

Main 2 Relay +Check zone of Main 1 will be used for Busbar trip decision. Hence Main

and chech zone will be from different CT core Expected date of completion= June

2018.


Separate cores will be used for main zone and check zone when the new bus bar

scheme is implemented, which is proposed to be commissioned by January 2019.


Will be rectified by 31.01.2019

Pending

3 Bus 110KV Protection Bus bar protection is not available for 110kV bus at Edamon Mail dated 03.02.2018:

This is being considered. As per present standards, Busbar protection is not mandatory

for 110 kV Bus. The 110 kV Bus at Edamon is very small.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. Since

providing BBP at 110 kV level is not mandated by currant regulations, KSEBL

requested to drop the item, and assured that it would be taken up seprately.

Accordingly, PCSC forum agreed to drop the Item.

Dropped

4 Kundara and

Edappon

220KV Protection It was observed that DEF and Brocken conductor are enabled in Main-2 distance relay and

not enabled in Main-1 distance protection (EPAC 3100) of Kundra and Edappon feeder.


These feeders belongs to PGCIL and action pending with PGCIL (SR-II).


Rectified

Complied

5 Tirunelveli-1&2 220KV Protection It was observed that the load encroachment blinder was encroaching inside zone-1 reach for

these feeders which needs review.



Mail dated 19.12.2018 & Mail dated 19.01.2019:

Pending with PGCIL.

Pending

6 Tirunelveli-1&2,

Sabarigiri-1,2&3,

Pothencode-1&2

220KV Protection Tirunelveli-1&2, Sabarigiri-1,2&3, Pothencode-1&2 feeders were having same Make for Main-

1& Main-2 relay (ABB , REL-670). It is proposed to have different makes for Main-1 & Main-2

relays.


Pending for want of CEA's reply. In response to the draft report of CEA's protection

philosophy, KSEBL has forwarded favourable remarks for maintaining same make Main

I & II relays. Hence this replacement work is in hold, waiting CEA's reply.


Thinunelveli 1 Main 2 relay replaced with different make.The rely of Thirunelveli 2 will

be replaced in the next feeder shutdown work.Procurement of relays for remaining

feeders under process

Pending

1) 220 kV Edamon SS [18-20 January, 2016]

KSEBL

40/95

Annexure-VI

Page 40 of 95

7 Tirunelveli-1&2,

Sabarigiri-1,2&3,

Pothencode-1&2

220KV Protection Reverse zone is not provided in Main-2 distance relays (ABB, REL-670) in Tirunelveli-1&2,

Sabarigiri-1,2&3 and Pothencode-1&2. The same is not available in the terminal of the relay.

The application configured by the manufacture for three zones only.


Zone 4 has been provided for Thirunelveli 1&2 feeders .Offer from Manufacturer for

the Firmware upgradation of SBEM1,2&3 and EMPC 1&2 (to enable Zone 4) . Time

synchronization of Thirunelveli 1&2,SBEM 1,2&3 and EMPC1&2 will be taken up

without delay.

Expected date of completion= June 2018.


Work Completed

Complied

8 ICT-1 220KV /

110KV

Protection HV and LV side backup overcurrent and earth fault protection for 220/110kV ICT-1 is non-

directional. It was informed that the time of operation transformer backup earth fault and

over current protection has been co-ordinated with the 110kV and 220kV line directional

earth fault protection.


Rectified

Complied

9 Sabarigiri-1 &

Tirunelveli-1&2

220KV Protection Auto reclose function was tested for 220kv Sabarigiri-1 feeder. Same was found to be in-

order. Auto-reclose function was kept in disable condition in Tirunelveli-1&2 feeders due to

OPGW works.


Rectified

Complied

10 Sabarigiri-1,2&3 220KV System Both channel-1&2 of PLCC has been provided in a single PLCC panel for Sabarigiri-2&3, which

are fed from a single power supply module inside the panel.


Now Two DC sources are connected to PLCC panel. Rectified.

Complied

11 Sabarigiri-1&3 220KV Protection Electrical interlock between breaker and isolator is not provided for the 220kV bays. Manual

operation of isolator and earth switch is being done. Mechanical interlock is provided

between earth switch and isolator and same was verified.


Rectified.

Complied

12 ICT-1 220KV /

110KV

Equipment Emulsifier and hydrant system to be provided for firefighting of 220/110kV transformers. Fire

prevention wall to be provided between transformer banks.


Form type extinguishers and Fire wall are provided now. Rectified.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. KSEBL was asked to

provide Emulsifier and Hydrant system for fire-protection of 220/ 110 kV

transformers.


Foam type extinguishers, Fire wall and water hydrant all are provided now.

Pending

13 Sabarigiri-1,2&3 220KV Equipment It was observed that the SF6 gas pressure in Sabarigiri-1,2&3 breaker was not uniform for all

the breaker poles.


Now SBEM#2 and 3 been replaced by Hybrid switch gear and SBEM#1 by New SF6

Breaker. Rectified.

Complied

14 ICT-2 220KV /

110KV

Equipment ICT-2 is not in working condition. It was informed that spare transformer of 200VA will be

commissioned


It is in Procurement stage. Expected date of completion= June 2019.


It is in Procurement stage.

Pending

15 ICT-1 & 2 220KV /

110KV

Equipment Oil sump pit for transformer is not available for ICT. Mail dated 03.02.2018:

Now provided. Rectified.

Complied

16 ICT-1 220KV /

110KV

Equipment Lightening arrestor is not provided on 110kV side of 220/110kV transformer (ICT-1) . RTCC

and cooler control cabinet was observed to be not in working condition. Provided in the 110

KV Bus and it will be relocated to transformer.


LA are now provided on 110 kV side. RTCC are now in working condition. Rectified.

Complied

17 AC System 415V System Auxilliary supply from 11kV/0.415kV transformer-1&2 is connected to a common incomer

(breaker) in ACDB panel through a manual changeover switch. It is suggested to implement

auto bus transfer scheme


Now incorporated in the new ACDB which will be installed by February 2018.

Expected date of completion= February 2018.


Completed

Complied

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18 DG set 415V Equipment Remote start for DG from ACDB room is not available. AMF panel is not provided for DG set. Mail dated 03.02.2018:

New ACDB panel with AMF facility has been procured and will be retrofitted with the

old panel shortly.

Expected date of completion= April 2018.


Completed

Complied

19 Sabarigiri-1,2&3 220KV Protection Direct transfer trip is not available and suggested to adopt the same for all Sabarigiri- Edamon

(SBEM) feeders.


These features are facilitated in the new protection coupler, which will be energised in

June 2018. Expected date of completion= June 2018.


Pending

Pending

20 Tirunelveli-1&2,

Kundara, Edappon

220KV Protection Power swing block enabled for all zones of Kundara, Edappon and Thirunelveli (PGCIL

owned) feeders.


These feeders belongs to PGCIL and action pending with PGCIL.


Action pending with PGCIL

Pending

21 Sabarigiri-1 220KV Protection In the control & relay panel following has been observed:

a) Isolator Earthswitch open indication lamp was not working.

b) Ammeter for R&B phase not working

c) Digital Voltmeter for YB phase not working

d) Digital Frequency meter not working


Item (a) Rectified and procurement of the balance is underway. a) done. b,c & d will

be completed in June 2018.


Item (a) Rectified and procurement of the balance is underway.

Pending

22 Sabarigiri-2 220KV Protection In the control & relay panel Isolator Earthswitch open indication lamp was not working. Mail dated 03.02.2018:

Rectified

Complied

23 Pothencode-1&2 220KV Protection In the control & relay panel Isolator close, Earthswitch open indication lamp was not workng. Mail dated 03.02.2018:

Rectified

Complied

24 Edappon 220KV Protection In the control & relay panel following has been observed:

a) Carrier In/out selector switch Handle is not available

b) Isolator open/close handle was broken

c) Isolator close indication lamp was not working.

d) Old name plate Kayamkulam has to be removed.

c) Annunciator not working


These feeders belongs to PGCIL(old C&R panels) and action pending with PGCIL (SR-

II).


Rectified

Complied

25 Kundara 220KV Protection In the control & relay panel following has been observed:

a) Carrier In/out selector switch Handle is not available

b) Isolator open/close handle was broken

c) Isolator close indication lamp was not working.


These feeders belongs to PGCIL (Old C&R panels) and action pending with PGCIL (SR-

II).

Pending

26 Tirunelveli-1&2

Kundara, Edappon,

Pothencode-1&2

220KV Protection Zone-4 (Reverse zone) setting should cover 50% of shortest line. Mail dated 03.02.2018:



Action Pending with PGCIL

Pending

27 Pothencode-1&2,

Sabarigiri-1,2&3

220KV Protection Zone-4 (Reverse zone) time delay has been kept as 1.1sec- For these feeders for reach

setting 50% ( Shortest line in the local Bus) and Z3 resistive reach has been taken as per the

recommendation of Ramakrishne committee. With this setting the faults in the line with

resistive reach of Z3 may be seen by the Z4 of other relays in the bus. Also the lines are

going through forest area and frequent trippings occured of this nature,hence a time setting

which is higher than Z3 is selected.


This matter has been already forwarded to SRPC Awaiting final report from CEA's

Protection philosophy.


noted that this kind of special requirement was only for a few set of lines

going through forest area. Based on the explanation given by KSEBL, PCSC

forum agreed to close the Item.

Complied

28 Tirunelveli-1&2 220KV Protection Zone-4 (Reverse zone) Fault resistive reach setting not same as Zone-3 resistive reach

setting




Action Pending with PGCIL

Pending

29 Tirunelveli-2 220KV Protection Upolmin for Tirunelveli-2 Main-1 relay is set at 20% it should be 1% Mail dated 03.02.2018:

Rectified.

Complied

30 Tirunelveli-1&2 220KV Protection t1Min and K1 for DEF is set different in Tirunelveli-1&2 Mail dated 03.02.2018:

Rectified.

Complied

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31 Tirunelveli-1&2,

Kundara, Edappon

220KV Protection For PSB as per PGCIL recommendation all the zones are blocked Mail dated 03.02.2018:

These feeders belongs to PGCIL and action pending with PGCIL.


Action pending with PGCIL

Pending

32 ICT-1 220KV Protection ICT differential slope setting was observed to be different Mail dated 03.02.2018:

Slope settings adopted as per differential slope equation and relay manufacture

recommendation. Expected date of completion= June 2018.


Slope settings adopted as per differential slope equation and relay manufacture

recommendation

Complied

33 ICT-1 & Bus 220KV Protection For ICT-1 single DC supply is available. Mail dated 03.02.2018:

Work in progress .control wiring almost done Will be completed within February 2018.


Dual DC supply available

Complied

34 General 220KV Protection It was observed that an intentional delay of 1.1 Sec is provided for line Directional earth fault

protection. It was proposed that the directional earth fault protection should get enabled only

in the event of distance function not able to sense the fault and blocked in the event of

pickup of distance function. No intentional delay is desired for DEF.


Needs an edit in application configuration. correction work in progress for KSEB

feeders and for PGCIL feeder correction is pending with PGCIL.



Correction work in progress for KSEB feeders and for PGCIL feeder correction is

pending with PGCIL

Pending

35 General - - Rusting was observed in lattice structure and bay equipment’s in Pothencode-1&2 bays. It

was informed that the bay will be replaced by Hybrid switch gear system during the

construction of double bus. It was observed that dummy gland holes in marshalling boxes

are not covered.


All been replaced by new ones. Rectified.

Complied

36 General - Equipment Standby air compressor is not available for breakers with pneumatic operating mechanism.

Rusting was observed in compressor provided in Sabarigiri-3 breaker.


Now this pneumatic system has been completely removed from the sub station.

Rectified.

Complied

37 General - - ANSI numbering system for bays is not provided. Phase identification for bay not properly

done.


This will be done on completion of Double Bus construction.



In progress, 31-12-2018.


In Progress 31.03.2019.

Pending

38 General - - Smoke detection system to be provided in control room Mail dated 03.02.2018 & 19.12.2018:

Will be provided.

Pending

39 General - - At present there is no communication facility is available between control room and yard.

Walky-talkie system to be provided for communication between switchyard and control room

for facilitating switchyard operations.

Mail dated 03.02.2018 & 19.12.2018:

Will be provided.

Pending

40 General - - Auto recloser ON/OFF switch shall be provided separately for all feeders. Mail dated 03.02.2018:

At present, the station Engineer put the Auto-reclosure out of service, through

Laptop/ HMI, when ever such requirement arises. Hence separate switch is not

required in the present condition. It is requested to drop this item.

The issue was discussed in PCSC-76 meeting held on 26.07.2018.KSEBL was

asked to provide Auto-Reclosure ON/ OFF switch separateli in all feeders.

KSEBL assured that the remark would be complied by August, 2018.

Mail dated 19.12.2018 & 19.01.2019:

work in progress, 31-12-2018


work in progress

Pending

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41 General - - Considering the better operation practices the following shall be considered

a) Operation may be done by SCADA system with remote operation facility

b) Thermo vision survival cameras with remote viewing to be provided

c) 2 Nos BUS coupler may be provided in the proposed double bus system


(a) This will be considered while an upgradatioin work take place.

(b) Procurement process started. will be completed in June 2018.

(c) Expected to be completed within June 2018.


Pending

Pending

42 General - - The present C&R panels for Edappon and Kundara, Bus Coupler and Bus Bar are observed

as old. Main-1 relay (EPAC 3100) does not have provision for collecting history of operation

and DR.


These feeders belongs to PGCIL(old C&R panels) and action pending with PGCIL (SR-

II).


Rectified.

Complied

43 General - - As part of good safety practices the followings may be considered

a) Industrial type switches and sockets for control room

b) Fire exit to be in proper direction

c) LED lightings may be provided as the part of energy conversation


The corrective action will be taken in a phased manner.


Work in progress, 31-12-2018

Pending

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Equipment/ System

auditated


Constituent)

1 Vallur 400 kV CB Pole discrepancy time delay kept as ber below

i. Line-1 main Circuit Breaker - 2.5 sec,

ii. Tie Circuit Breaker- 2.0 sec,

ii. Line-2 main Circuit Breaker-3.0 sec

Mail Dated 29.01.2018

PD Time set uniformaly as 2.5 Seconds.

Complied

2 NCTPS 1 & 2 400 kV CB Tie Breaker bay not yet commissioned Mail Dated 29.01.2018

Will be commissioned by June-2018.


Time line requested upto 31.10.2018



Pending

3 ICT 2,3,4 & 5 400 kV ICT CB Pole discrepancy time delay kept as ber below

i. ICT-5 - 1.0 sec,

ii. ICT Tie - 1.0 sec

iii. ICT-4 - 0.1 Sec

iv. ICT-2&3 - 2.1 Sec


PD Time set uniformaly as 0.6 Seconds.

Complied

4 Thiruvalam & SVC 400 kV CB Switchyard isolator electrical interlocks were observerd to be unhealthy for 400 & 220 kV

system.


Line clearance is required for checking the isolator interlocks which involves all bay

isolator and earth switch auxillary contacts. Will be completed by 31.03.2018.

Mail Dated 07.08.2018:

Will be completed before 31.10.2018



Pending

5 NCTPS 1 & 2 400 kV Main-II It was observed in Main-2 (D60) Relay that there is provision for enabling one stage of Over

voltage protection. Hence O/V stage-2 has been enabled in main-2 relay. In the event of

outage of main-1 relay only O/V stage-2 protection will be available.


The D 60 Relay have provision for only one element for overvoltage Stage-I due to

design limitation. Two stages of O/V protection is adopted in Main-I (P543) Relay.

Complied

6 SVC-1&2 230 kV Main-1 & 2 It was observed in main-2 (D60) Relay that there is provision for enabling one stage of Over

voltage protection. O/V stage-1 has been enabled in main-1 relay and O/V stage-2 in main-2

relay. In the event of outage of any one main relay only one stage of O/V protection will be

available.


Main 1 D60 relay replaced in SVC-1 & 2 feeders by P442 relay on 23.01.2018 &

10.01.2018 respectively. The D 60 Relay have provision for only one element for

overvoltage Stage-I due to design limitation. Two stages of O/V protection is adopted

in Main-I (P442) Relay.

Complied

7 Korattur &

Thiruverkadu

230 kV Relay panel Carrier Protection for the corresponding Lines were observered not available. However it was

informed that Digital Tele-Protection Coupler is proposed for the corresponding feeders.


The Korattur bay name have been changed as Koyembedu feeder. The carrier scheme

will be established for Thiruverkadu feeder by 31.01.2018. Fibre Optic link will be

established for Koyembedu feeder.


Complied.

Complied

8 Manlai-1&2 230 kV Relay panel Auto recloser for the corresponding line is not available. It was informed the frequent

permanent fault prone zone due to chemical pollution at manalai S/S. Hence ARC not

enabled.


Manali 230kV AIS was upgraded to 400kV GIS Substation. Cable portion is involved in

the line. Hence, Auto Reclosure for 230kV Manali - 1 & 2 feeders not enabled.

Complied

9 Korattur 230 kV Relay panel Trip circuit supervision for Trip Coil-1 is not in working condition. It was informed that

replacement of faulty relay is under process.


Complied.

Complied

1) 400/ 230 kV Alamathy SS [4-6 January, 2016]

TANTRANSCO

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Equipment/ System

auditated


Constituent)

10 General Zone-4 time delay is kept as 1.1 sec in 400 kV Line . Mail Dated 29.01.2018

The Zone 4 time is set at 1.1 sec as per approved guidelines.


TANTRANSCO was sked to revise Zone-4 (reverse) time setting to 0.5 sec in

line with Ramakrishna Committee guidelines.


Will be completed by 31.08.2018


Complied

Complied

11 General Auto recloser not available for the all 400 kV tie breakers. Mail Dated 29.01.2018

Auto Reclosure scheme for Tie CB enabled in SVC Bay. For Vallur and Thiruvalam bay,

the scheme will be checked during next LC.


Thiruvalam tie bay CB status wiring completed. For Vallur feeder bay CB status wiring

under progress. The scheme will be implemented by 31.08.2018.



Pending

12 General STUB protection not available for 400 kV feeders. Mail Dated 29.01.2018

For enabling of STUB Protection, Line Isolator status from swithyard is being checked

for the scheme. Will be completed by June-2018.


Complied

Complied

13 General Load encroachment is not available in 400 & 230 KV feeders. However it was informed that

the resistive reach have been suitably calculated to take care of the same.


Suitable setting adopted to avoid load encrocachment.

Complied

14 General Observed redundant power supply (48V) not available in RTU panel. Pending

15 General Observed redundant data transfer (to LDC) channel is available however manual change

over is being done in the even of failure of main channel.

Pending

16 General Stand alone Event Locker is not available for the station. Complied

17 General Disturbance recorders in 400 & 230 KV feeders are not time synchronised with GPS. Complied

18 General Main-1 & Main-2 relays found to be of same make in 400 kV S.V.Chattiram Line -1&2 and

230 kV Koratur & Manali -1.


Main-1 D60 relay replaced in SVC-1 & 2 feeders by P442 relay on 23.01.2018 &

10.01.2018 respectively.

In 230kV Manali-1 feeder & 230kV Thiruverkadu feeder, Main-2 P442 relay will be

replaced with D60 relay (released from SVC-1 & 2 feeders), by February 2018.


Complied

Complied


Will be implemented in new RTU which is under procurement stage.


Under procurment stage.


New RTU P.O issued . Time line requested upto 30.06.2019


Commissioning of DR & EL collection system alongwith GPS is under progress.


Completed on 09.01.2018


Time synchronising with GPS was provided for 400 & 230kV protection system on

09.01.2018.

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Equipment/ System

auditated


Constituent)

19 General The Emulsifire fire systems are found to be not erected and commisioned for ICT-2,4 & 5. Mail Dated 29.01.2018

Estimate submitted for approval.


Under procurement stage. Time line requested upto 31.10.2018


Fire fighting system Under procurement stage. Time line requested upto 30.06.2019

Pending

20 General Direct Trip not available for 230kV feeders. This may cause delayed fault clearances from

remote end in the event of operation of LBB protection.


CTs are on Bus side. Carrier inter trip scheme is available for remote end trip.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. TANTRANSCO was

asked to provide Direct Trip transfer shceme to 230 kV feeders.


CTs are on Bus side. Carrier inter trip scheme is available for remote end trip.

Complied.


complied

Complied

21 General Non directional Backup Over current provided in HV/LV side of all Transformers. Mail Dated 29.01.2018

Numerical relay procurement is under progress for enabling Directional O/C & E/F

protection.


Under procurment stage.



Pending

22 General Fire detection system is not healthy in control room. Mail Dated 29.01.2018

The healthiness of Fire detection system will be checked to bring back in to service.





Pending

23 General Walkie-talkie is not available for communication between switchyard and control room. Mail Dated 29.01.2018

Walkie Talkies provided.

(Complied).

Complied

24 General Auto changeover is not available in ACDB for 0.415 kV Auxiliary supply 1 & 2. DG set was

also observed to be operated in manual mode.


The feasibility for auto change over will be studied for implemetation.





Pending

25 General CB On/Off & Spring Charged Mechanical indications in 230 kV CB are not visible in

switchyard.


Rectified. (Complied).

Complied

26 General CB ON/Off and spring charged mechanical Indication functions are not working in 230kV

Manali 1 & 2 feeders circuits



Complied

27 General Name Plate details on bay Marshalling Box of 230 kV Thiruverkadu feeder circuit is

mismatching



Complied

47/95

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Equipment/ System

auditated


Constituent)

28 General Corrosion observed in Earth mat risers and CB/Isolator operating mechanism boxes ,

junction boxes and oil conservator tanks of ICTS


Estimate will be evolved soon.


Work under progress.


work under progress. Time line requested upto 31.03.2019

Pending

29 General Rusting was observed in CB operating mechanism boxes of 230 kV OPG -1 & 2 feeders. Mail Dated 29.01.2018

Rectified.

(Complied).

Complied

30 General For 230 kV feeders for OPG-1&2 and NCTPS bypass isolator (Placed in gantry) Moving

contacts were found to be missing.

Procurement work under progress.


Procurement work under progress.


230 KV OPG 1 & 2 feeder completed.

NCTPS is pending. Time line requested upto 31.03.2019

Pending

31 General Few Indicating meters in control panel were found to be unhealthy. Mail Dated 29.01.2018

Rectified all except ICT3 & 110kV Avadi-2 feeder.


Work under progress.


--- Completed.

Complied

48/95

Annexure-VI

Page 48 of 95


Equipment/ System

auditated


Constituent)


Constituent)

1 Mail dated 29.01.2018:

Suitable setting adopted to avoid load encrocachment.

Complied

2 Mail dated 29.01.2018:

LAS Erection and Connecting the earth pit gantry take off Tower to Station Earth mat

Works will be completed in July-2018.


After erection of LAS it will be completed. Time line requested upto December-18.


After erection of LAS it will be completed. Time line requested upto March 2019

Pending

3 Mail dated 29.01.2018:

Materials supplied and will be commissioned.


Materials drawn.Work will be completed December-18


Materials drawn, erection estimate sanctioned, civil works completed and it will be

completed March 2019

Pending

4 Mail dated 29.01.2018:

Proposal has been evolved.


Proposal has been evolved.


Estimate Stage

Pending

5 Mail dated 29.01.2018:

Metal Spreading will be provided for each Bay.


under estimate stage.Time line requested upto 31.12.2018



Pending

6 Mail dated 29.01.2018:

Will be completed by February-2018.


230 kV BBP panel has to be replaced.(Static relay). Until such time DC Supply change

over switch will be provided by August 2018.


230 kV BBP panel has to be replaced.(Static relay). Until such time DC Supply change

over switch will be provided before March 2019.

Pending

2) 230 kV Alundur SS [4-6 January, 2016]


DC Supply selection changeover switch to be provided in BB panels

Load Encroachment has not been enabled as the the estimated load is much higher than Zone-3 resistive reach

Transmisssion line earthwire earthing was done at earth pit gantry take-off tower, which may be reviewed for connection to station earth-mat

Lightning Arrestors for all 230 kV feedses are to be provided

Fire protection for 100 MVA, 230/ 110 kV Auto Transformers to be provided

Swtichyard area was observed to be covered with cement flooring. Providing metal spreading may be examined for ensuring safe touch & step

potential limits

49/95

Annexure-VI

Page 49 of 95


Equipment/ System

auditated


Constituent)

7 Mail dated 29.01.2018:

Will be completed by February-2018.


Provision for DC supply changeover by a separate coupler switch between the two DC

sources will be provided by August 2018.


Provision for DC supply changeover by a separate coupler switch between the two DC

sources will be provided before January 2019.

Pending

8 Mail dated 29.01.2018:



Commissioned on 30.01.2018

Complied

9 Mail dated 29.01.2018:



Commissioned on 30.01.2018

Complied

10 Mail dated 29.01.2018:

The Zone 4 time is set at 1.1 sec as per approved guidelines. Reach settings will be

revised during Relay testing.


Setting will be revised as per Ramakrishna Committee before 31.08.2018


Complied

Complied

11 Mail dated 29.01.2018:

Complied.

Complied

12 Mail dated 29.01.2018:

Will be completed by March-2018.


Replacement of BBP panel (Numerical relay) will be completed by August 2018. Work

will be completed by August 2018.


Replacement of BBP panel (Numerical relay) will be completed by February 2019. Work

will be completed by February 2019.

Pending

13 Mail dated 29.01.2018:

Will be completed by March-2018.


Check synchrosing is done thro'Synchronizing trolley.

Complied

14 Mail dated 29.01.2018:

Programmed during April-2018.


Completed. Station Earth mat measured on 20.4.2018, the combained value is 0.06

ohm

Complied

Resistive reach settings for Zone-1, Zone-2 & Zone-3 may be reviewed in line with Ramakrishna Commitee recommendations

DR to be triggerred for LBB and BBP operations

Check-synchronizing relay to be provided in Synchronizing trolley.

Station earth mat resitance was measured to be 0.18 ohm on 07.07.2016

Provision for DC supply changeover by a separate coupler switch between the two DC sources may be examined for improving the reliability.

Time synchronization of various protection relays with GPS was not available. TANTRANSCO informed that GPS facility was under prcurement stage

Stand alone Event Logger not available. TANTRANSCO informed that GPS facility was under prcurement stage

Zone-4 settings (for reactance reach, resistivee reach and time settings) may be reviewed in line with Ramakrishna Commitee recommendations

50/95

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Page 50 of 95


Equipment/ System

auditated


Constituent)


Estimates sanctioned. Procurement of Digital type meters is under progress and will be

replaced by July-2018.


Procurement of Digital type meter is under progress and will be replaced by December-

2018.


Procurement of Digital type meter is under progress and will be replaced by March

2019Mail dated 29.01.2018:

Estimate sanctioned and Procurement is under progress.


under procurement stage.


Procurement stage time line requested upto March 2019


Estimate is evolved and the works will be completed in July-2018.






Estimate is evolved and the Civil works will be completed.






Complied.


Estimate sanctioned. Procurement is under process and Erection works will be

completed by July-2018.


One no.provided on 230 KV Alundur - Trichy-I Feeder, the other work will be

completed before December-2018.


One no.provided on 230 KV Alundur - Trichy-I Feeder. For 4 feeders work under

progress and for 2 feeders & 230 & 110 BBP estimate under sanction. The work will be

completed by March 2019.

f) Alarm anunciator panel in all 230 kV feeders, Auto HV - I & II, Bus coupler

15 Pending

a) All analog meters to be replaced by Digital meter

b) D.G. Set with enhancement of 75 kVA Auto/ Manual control from control room itself (remote operation)

c) Isolator position in control panels

d) Entire gravel filling in 230 kV & 110 kV yard

e) Extension of Battery room and Carrier room for providing panels

TANTRANSCO informed the following had been been included in the propopsed R & M works:

51/95

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Page 51 of 95


Equipment/ System

auditated


Constituent)

16 Mail dated 29.01.2018:

Materials supplied and will be commissioned.


Materials drawn. Will be comleted before December-2018.


Complied

CompliedLine CVT's to be used for feeder protection by commissioning Y-ph & B-ph CVT's in all 230 kV feeders. TANTRANSCO informed that the related works

had already been taken under PSDE funding.

52/95

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Equipment/ System

auditated


Constituent)


Constituent)

1 Mail Dated 07.08.2018 & 23.01.2019:

Complied

Complied

2 Mail Dated 07.08.2018:

Will be completed by 30.08.2018

Complied

3 Mail Dated 07.08.2018:

Complied

Complied

4 Mail Dated 07.08.2018:

Complied

Complied

5 Mail Dated 07.08.2018:

Loads will be segregated to feed as radial load from Palavady SS. Provision of

Auxililary source from Vellichanthai Which inturn fed from Kariamangalam 230 kVSS is

under progress.


Under progress

Pending

6 Complied Complied

7 Mail Dated 07.08.2018:

will be completed by 30.09.2018.


Directional O/C Protection Enabled and Directional Earth fault will be provided before

Jan 2019.

Pending

8 Mail Dated 07.08.2018:

Complied

Complied

9 Mail Dated 07.08.2018:

Complied

Complied

10 Mail Dated 07.08.2018:

will be provided by 30.09.18.


DTPCs were alloted . Time line requested upto March 2019

Pending

3) 400/ 230-110 kV Palavadi SS [16-17 May, 2018]


Auto-reclosure dead-time may be unformly adopted across all 400 kV and 230 kV feeders as 1 sec.





kept as 0.5 sec.

It is seen that 110 kV Dharmapuri and 110 kV Pennagaram lines did not have circuit breaker at remote ends. Steps may be taken provide them to

facilitate proper discrimination of faults.

It is seen that REF protection has not been provided for 125 MVAR Bus-Reator, which may be provided.

Directional O/C Protection (high-set & IDMT) and Directional E/F protection (high-set & IDMT) shall be provided on both sides of 400/ 230 kV ICT's

and 400/ 110 kV ICT's.

It is seen that the philosophy of Group-A & Group-B Protections has not been followed in case of ICT's. It is recommended to adopt the same with

the following model segregation of protections:

Group-A:

Differential, DOCE (HV), Overflux (HV)

Group-B:

REF, DOCE (LV), Overflux (LV)

It is also recommended to arrange supply for these two groups from two different DC supplies.

It is seen that speech channel has not been provided as part of substation communication in any of the 400 kV & 230 kV feeders. Steps may be taken

to provide the same.

It is observed that Protection Channels of Thiruvalam lines 1 & 2 have been implemented from same DTPC. Similarly Protection channels of Mettur

lines 1 & 2 have been implemented from another DTPC. Steps may be taken to implement protection channels of each line from one/ two dedicated

DTPC's.

Time settings and Reactive & Resistive reaches of Z2, Z3, and Z4 (reverse) of distance relays for 400 kV and 230 kV feeders are observed to be not in

line with Ramakrishna Committee guidelines, which may be reviewed appropriately to bring in line with them.

Re-Trip feature to be provided for Breaker Failure Protection for 400 kV & 230 kV circuit breakers.

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Equipment/ System

auditated


Constituent)

11 Mail Dated 07.08.2018:

Provision of Auxililary source from Vellichanthai Which inturn fed from Kariamangalam

230 kVSS is under progress


enhancement from 10 to 16 MVA transformer under progress and strengthening of

33KV line from Vellichandai to Papparapatty also be taken up. Time line requested

upto March 2019

Pending

12 Mail Dated 07.08.2018:

Provision of 250kVA capacity will be ensured by 30.11.18.


Under procurement stage time line requested upto March 2019

Pending

13 Mail Dated 07.08.2018:




Pending

14 Mail Dated 07.08.2018:

Will be checked and corrected by 30.09.18.


Complied

Complied

15 Mail Dated 07.08.2018:

Will be checked and corrected by 30.09.18.


All Earth pit combined values measurement works are compiled and records are

updated.

The issue was discussed in PCSCM-81 held on 24.01.2019. TANTRANSCO was

asked to provide a copy of the records containing latest values of measured

earth-pit resistance values to SRPC Secretariat.

Pending

16 Mail Dated 07.08.2018:

will be completed by 30.09.18.



Pending

17 Mail Dated 07.08.2018:

Spikes will be provided by 30.09.18



Pending

18 Mail Dated 07.08.2018:

will be ensured.



Pending

19 Mail Dated 07.08.2018:


Complied

20 Mail Dated 07.08.2018:

Complied


complied

Complied

It is seen that Palavadi is a SAS station; however no CC cameras have been provided in the switchyards to exert effctive monitoring. Steps may be

taken to provide the same at suitable locations for better security.

Equipment labeling for proper phase-sequence and Bay Element labeling may be provided in all 400 kV & 230 kV & 110 kV switchyards.

It is seen that even though two AC auxiliary supplies are being provided from two different sources (33 kV/ 11 kV Adagapady SS, and 33 kV/ 11 kV

Paparapatty SS), since both these supplies have been derived from the same source substation, viz., 110/ 33 kV Pennagaram SS, the independency

of AC auxiliary supplies is not ensured. It is recommended to provide redundant AC auxiliary supply from another suitable substation in addition to

110/ 33 kV Pennagaram SS.

It is seen that the provided 100 kVA DG set is insufficient for catering to mandated substation loads. It is recommneded to provide a DG set of

suitable (higher) capacity. Steps may also be taken to maintain sufficient fuel stock to take care of unforeseen emergencies.

It is observed that DG-Set starting and Supply changeover among AC supplies & DG set are being done manually. Steps shall be taken to provide

them in auto-mode.

It is observed that earth-resistance for some of the 400 kV earth-pits (grid-connected) esp. near ICT's are found to be higher than the mandated limit

of 0.5 ohms. (measured values are found to be varying between 0.4 ohms - 20 ohms). It is recommended to attend to them on priority basis, and

take necessary steps to bring them within the mandated limit of 0.5 ohms.

It is found that the furnished values of earth-pit resistance (with and without grid-connected) are at variance with the values displayed in all (400 kV

& 230 kV & 110 kV) switchyards, and have not been measured after commissioning of the same in March, 2017. It is recommended to carry out

measurement of earth-resistances of all earth pits (400 kV & 230 kV & 110 kV switchyards) on yearly basis, and keep updated records with the

substation along with suitable earth-mat lay-out diagrams. A copy of the same may also be furnished to SRPC Secretariat.

It is observed that 110 kV feeders earthwire earthing has been done at respective gantry take-off towers, which may be reviewed for connection to

station earth-mat.

It is observed that 110 kV switchyard has been provided with only one lighning mast to provide protection from direct lightning strokes. It is

recommended to provide sufficient no. of lightning masts to cover entire 110 kV switchyard.

The following equipment may be purchased/ provided for maintenance of various switchyard equipment:

(i) Tan delta meaurement kit.

(ii) Digital Earth-resitance measuring kit

A suitable lifting device/ aerial work platform may also be provided and maintained with the substation to carry out testing on various equipment.

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21 Mail Dated 07.08.2018:




Pending


Constituent)

1 Mail dated 30.01.2018 & 13.03.2018 & 10.07.2018:

Existing Control & Relay Panels installed with static relays are proposed to be replaced

with new control panels installed with numerical relays under the project of

Upgradation of existing static relays and replacement of sub-station equipments at

230KV Villianur and Bahour Auto Sub-Station at the cost of Rs.10,56,16,191/- through

PSDF funding. Tendering process for award of work on labour contract basis for the

above said work is almost over and waiting for the approval of Puducherry

Government to place order at the lowest tenderer.


A Work Order has already been placed at M/s.GE T&D India Limited, Chennai vide

Work Order No.784/ED/SE-cum-HOD/EHV/PLCC&Lines/F-PSDF/2018-19, dated

22/10/2018 towards Design, Supply, Erection, Testing & Commissioning of 230KV &

110KVC & R Panles, SAS and PLCC equipments at 230/110KV Villianur and Bahour

Auto Sub-Stations under PSDF funding at the cost of Rs.4,47,42,293/- wherein

provision has been given for Main-II protection with with Directional E/F protection for

230KV feeders and whereas Direction O/C and E/F protection as backup for Main-I

protection for 110KV feeders. The work is scheduled to be completed by June 2019.

Pending

2 Mail dated 30.01.2018 & 13.03.2018:

As per the recommendation of Protection Audit Team, a Detailed Project Report at the

cost of Rs.14,85,42,653.21 has been prepared to replace the existing aged equipments

and provide additional equipments at 230KV Villianur and Bahour Auto Sub-Station and

sent to higher authority to obtain sanction under PSDF funding. (copy enclosed)


A tender has been floated on 15.05.2018 to invite e-tender to replace the existing aged

outdoor equipments along with deteriorated RCC supporting structure. Provision has

been given to provide Line CVTs in all phases in the fore said tender. The e-tender has

been opened and Technical evaluation is under process.


Inservice 230KV Neyveli-Villianur Line is already provided with CVTs in all phases. In

the tender floated on 15.05.2018 to invite e-tender to replace the existing aged

outdoor equipments along with deteriorated RCC supporting structure in 230/110KV

Villianur Auto Sub-Station, provision has been given to provide Line CVTs in all phases

in the 230KV Pondy-Villianur Line. Lowest tenderer has been identified and sent a

proposal to Government of Puducherry for obtaining approval for awarding work

order.

Pending

Puducherry ED

1) 230/ 110 kV Villianur SS [10 - 12 July, 2017]

Directional O/C & E/F protections to be provided for 230 kV & 110 kV feeders where Main-II is not provided; Directional E/F protection to be provided

for 230 kV & 110 kV feedes where Main-I & Main-II are provided

Line CVT's to be provided in all phases for all 230 kV lines.



55/95

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auditated


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3 Mail dated 30.01.2018 & 13.03.2018:

Existing aged Two sets of 110Volt Station Batteries have been replaced with two sets

of new 110Volt Station Batteries. Further, in addition to the existing one set of 48Volt

PLCC battery, one more 48Volt PLCC Battery has been provided. All the above three

batteries have been commissioned in the last week of January 2018. Wiring has to be

done to segregate the existing single circuit into two circuits.





batteries have been commissioned in the last week of January 2018. A Work Order has

already been placed at M/s.GE T&D India Limited, Chennai vide Work Order

No.784/ED/SE-cum-HOD/EHV/PLCC&Lines/F-PSDF/2018-19, dated 22/10/2018

towards Design, Supply, Erection, Testing & Commissioning of 230KV & 110KVC & R

Panles, SAS and PLCC equipments at 230/110KV Villianur and Bahour Auto Sub-

Stations under PSDF funding at the cost of Rs.4,47,42,293/- Completion of above said

work will ensure the wiring of Protection and Communication schemes with requisite

segregation. The work is scheduled to be completed by June 2019.

Pending

4 Mail dated 30.01.2018 & 13.03.2018:









A Work Order has already been placed to M/s.GE T&D India Limited, Chennai vide








Pending

5 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Protection & Communication wing of TAN TRANSCO Limited, Villupuram has been

requested vide Lr. No.347/ED/EE-Auto SS/AEE-M-VASS/F-4/2017-18, dated

21.09.2017 for revision of existing relay settings as per the recommendations of

Protection Audit Team.






Auto Sub-Stations under PSDF funding at the cost of Rs.4,47,42,293/- . At the time of

execution of work, Z4 (reverse) will be provided in all distance relays of 230KV and

110KV feeders. The work is scheduled to be completed by June 2019.

Pending

6 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:










Auto Sub-Stations under PSDF funding at the cost of Rs.4,47,42,293/- At the time of

execution of work, Z2 and Z3 (reactive & resistive) reaches & time settings will be set

in line with Ramakrishna Committee guidelines. The work is scheduled to be

completed by June 2019.

PendingZ2 and Z3 (reactive & resistive) reaches & time settings were observed to be not in line with Ramakrishna Committee guidelines, which may be

reviewed appropriately.

Redundant DC suppy for protection (110 V) and communication (48 V) applications to be provided with requisite segregation in wiring.

For 230 kV feeders, the present single-zone BB protection is to be reviewed and provided with two-zone operation & Check-zone operation.

Z4 (reverse) is to be provided in all distance relays of 230 kV & 110 kV feeders

56/95

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7 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:











execution of work, Auto-reclosure dead-time and reclaim-time for 230 kV feeders will

be revised to 1 sec and 25 sec respectively. The work is scheduled to be completed by

June 2019.

Pending

8 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:










Auto Sub-Stations under PSDF funding at the cost of Rs.4,47,42,293/-At the time of

execution of work, Power Swing Philosophy (Z1 --> Unblock; Higher Zones --> Block

for 2 sec) will be adoped unfiromly across all 230 kV feeders. The work is scheduled to

be completed by June 2019.

Pending

9 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:






Load encroachment feature will be enabled in 230 kV & 110 kV feeders during the time

of oncoming relay testing programme.

Pending

10 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:






During the next annual relay testing programme on 230 kV Pondy feeder, POR will be

enabled in place of the existing PUR.

Pending

Auto-reclosure dead-time and reclaim-time for 230 kV feeders may be revised to 1 sec and 25 sec respectively.

Power Swing Philosophy (Z1 --> Unblock; Higher Zones --> Block for 2 sec) is to be adoped unfiromly across all 230 kV feeders.

Load encroachment feature may be appropriately kept enabled in 230 kV & 110 kV feeders.

For 230 kV Pondy feeder POR may be used in place of the existing PUR.

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11 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:
















work will see the Main-I & Main-II protections or Main & back-up protections of

feeders are fed from different DC supplies. The work is scheduled to be completed by

June 2019.

Pending

12 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for REF protection for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

Pending

13 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for directional O/C protection for 100 MVA, 230/ 110 kV ICT-

1 & ICT-2. The work is scheduled to be completed by June 2019.

Pending

Steps to be taken to ensure that Main-I & Main-II protections or Main & back-up protections of feeders are fed from different DC supplies.

REF protection to be provided for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

Directionality to be provided for O/C protection of 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

58/95

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auditated


Constituent)

14 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for directional E/F protection for 100 MVA, 230/ 110 kV ICT-

1 & ICT-2. The work is scheduled to be completed by June 2019.

Pending

15 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for Overflux protection for 100 MVA, 230/ 110 kV ICT-1 &

ICT-2. The work is scheduled to be completed by June 2019.

Pending

16 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:
















work will see the Group-A & Group-B protections or Main & back-up protections of

ICT's are fed from different DC supplies. The work is scheduled to be completed by

June 2019.

Pending

Overflux protection to be provided for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

Steps to be taken to ensure that Group-A & Group-B protections or Main & back-up protections of ICT's are fed from different DC supplies.

Directional E/F protection to be provided for 100 MVA, 230/ 110 kV ICT-1 & ICT-2.

59/95

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auditated


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17 Mail dated 30.01.2018:

Various possible ways to connect the 110/22KV Villianur Sub-Station with nearby

110/22KV Korkadu SS by 22KV feeder is being explored.

Mail dated 13.03.2018 & 10.07.2018:

Division-EHV of this department has been requested vide Lr. No.714/Ed/EE-Auto

SS/AEE-M-VASS/F-4/2017-18, dated 27.02.2018 (Copy enclosed) to explore the

possibilities of providing another 200KVA, 22KV/440V station transformer I nearby

110/22KV Villianur SS that is charged by a 22KV feeder either from 110/22KV Korkadu

SS or Kurumbapet SS for providing AC auxiliary supply to 230KV Villianur Auto SS.


Survey for providing another 200KVA, 22KV/440V station transformer I nearby

110/22KV Villianur SS that is charged by a 22KV feeder either from 110/22KV Korkadu

SS or Kurumbapet SS for providing AC auxiliary supply to 230KV Villianur Auto SS has

been completed and is now at the stage of preparation of necessary estimate.

Pending

18 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for GPS based time-synchronization equipment for

synchronizing various 230 kV & 110 kV protection relays. The work is scheduled to be


Pending

19 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:










Work Order No.784/ED/SE-cum-HOD/EHV/PLCC&Lines/ F-PSDF/2018-19, dated




provision has been given for DR's with facility for automatic fault record downloading

to a central PC/ server. The work is scheduled to be completed by June 2019.

Pending

At present AC auxiliary supply is being provided from 440 Volt, 3phase, 50 Hz LT supply from 200 kVA, 22 kV/440 V Transformer connected directly

on the main bus of the nearby 110/22 kV Villianur SS. Since this substation is fed from 230/ 110 kV Villianur substation, steps may be taken to

provide redundant AC auxiliary supply by providing another 200 kVA, 22 kV/ 440 V transformer in the 110/ 22 kV SS that is charged from 22 kV

Korkadu feeder, and laying another 440 V cable from its secondary to thr AC supply changeover panel at 230/ 110 kV Villianur SS.

GPS based time-synchronization equipment may be provided for synchronizing various 230 kV & 110 kV protection relays.

Steps may be to taken provide DR's with facility for automatic fault record downloading to a central PC/ server.

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auditated


Constituent)

20 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:









A Work Order has already been placed to M/s.GE T&D India Limited, Chennai vide





provision has been given for Standalone Event Logger. The work is scheduled to be


Pending

21 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:




sent to higher authority to obtain sanction under PSDF funding. (copy enclosed)


A Supplementary Detailed Project Report submitted to Ministry of Power, National Load

Despatch Centre, Disbursement of Fund from Power System Development Fund at the

cost of Rs.11,56,26,890/- for attending the remarks of Porotection Audit conducted in

Villianur and Bahour Auto Sub-Stations in Puducherry. Additional calrifications has

been sought for and as well as approval of Government of Puducherry for balance

funding from Plan. As sought, proposal has now been sent to Government of

Puducherry for approval during December 2018 and the same is awaited.

Pending

22 Mail dated 30.01.2018 & 13.03.2018:




sent to higher authority to obtain sanction under PSDF funding. (copy enclosed). In

that DPR, replacement of existing deteriorated RCC supporting structures have been

proposed to be replaced with G.I. lattice structure.




been given to provide Line CVTs in all phases in the fore said tender.









Pending

It was observed that existing 100 MVA transformers had not been provided with fire protection. Steps may be taken to provide the same in

accordance with the relevant standards.

It was observed that supporting structures and equipment such as breakers, CT's, isolators, etc. In 110 kV switchyard had served thier full life. Steps

may be taken to refurbishing of 110 kV switchyard appropriately.

Standalone Event Logger may be provided.

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auditated


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23 Mail dated 30.01.2018:





that DPR, provision has been given to provide chemically treated PCC flooring, and

then covering it with suitable blue metal spreading in switchyard area.

Mail dated 13.03.2018 & 10.07.2018:

Vegetation & weeds grown in the switch yard area were manually cleared and now the

switch yard is kept clean. However, as a permanent measure, Detailed Project Report

at the cost of Rs.14,85,42,653.21 has been prepared to replace the existing aged

equipments and provide additional equipments at 230KV Villianur and Bahour Auto Sub-

Station and sent to higher authority to obtain sanction under PSDF funding. (copy

enclosed). In that DPR, provision has been given to provide chemically treated PCC

flooring, and then covering it with suitable blue metal spreading in switchyard area.


Agaist the request of Puducherry Electricity Department, a thorough survey has been

completed by Public Works Department, Puducherry towards laying of chemically

treated PCC flooring, and then covering it with suitable blue metal spreading in

switchyard area. They are under the process of preparing necessary estimates.

Pending

24 Mail dated 30.01.2018 & 13.03.2018:





that DPR, provision has been given to replace the existing dilapidated gantry &

equipment supporting (RCC) structures with G.I. lattice / tubular structures.




been given to provide Line CVTs in all phases in the fore said tender









Pending

25 Mail dated 30.01.2018 & 13.03.2018:

Action has been initiated to bring down the earth resistance value to less than 1ohm


Earth resistance values have been measured in the last total shutdown availed in this

station on 30.06.2018. Action has been initiated to bring down the earth resistance

value to less than 1ohm


Expenditure sanction for an amount Rs,4,74,684/- has been obtained for

strengthening of existing 22nos. Of earth pits provided in the 110KV yard at the first

instance. Work Order is to be issued shortly as Tender evaluation is underway to arrive

at the lowest tenderer.

Pending

Vegetation & weeding was observed in switchyard area. Steps may be taken to provide chemically treated PCC flooring, and then covering it with

suitable blue metal spreading in switchyard area.

It was observed that most of the existing gantry & equipment supporting (RCC) structures are in dilapidated state. Steps may be taken to replace

them with suitable lattice/ tubular structures.

Earth-resistance values for various earth-pits seem to be on higher side. Steps may be taken to bring it down to less than 1 ohm.

62/95

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auditated


Constituent)

26 Mail dated 30.01.2018:

Action has been initiated to Equipment labeling for proper phase-sequence

Mail dated 13.03.2018 & 10.07.2018:

The work of Equipment labeling for proper phase-sequence was completed on

13.03.2018.

Complied

27 Mail dated 30.01.2018:

Action has been initiated for Earthing of equipment including door-to-panel earthing.

Mail dated 13.03.2018 & 10.07.2018:

The work of Earthing of various equipment including door-to-panel earthing was

completed on 13.03.2018.

Complied

28 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Suitable canopy has been fabricated and kept on hand awaiting for shutdown to

provide over Buchholz relays


Complied. Buccholtz relays were kept provided with suitable canopy on 25.09.2018 to

prevent unwarranted trippings due to moisture ingress.

Complied

29 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Steps have been initiated to establish Standard Testing Lab and procurement of

essential testing equipments to cater to all 230 kV substations.




Pending

30 Mail dated 30.01.2018:

Detailed scope of the works included in proposed R & U works has already been

furnished vide Lr.256/ED/EE-MRT&MMC/F-SRPC/2017-18, dated 14.08.2017. (copy

enclosed)

Mail dated 13.03.2018 & 10.07.2018:



enclosed)

Complied

31 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:






At the time of next annual relay testing of 110KV feeders, Zone-1 reach will be

increased to 90 % of line length, and Zone-2 time-setting will be reduced to 150 msec

for 110KV feeders.

PendingIn view of radial operation of 110 kV feeders, Zone-1 reach may be increased to 90 % of line length, and Zone-2 time-setting may be reduced to 150

msec.

Equipment labeling for proper phase-sequence may be provided.

Earthing of various equipment including door-to-panel earthing to be properly ensured.

Buccholtz relays may be provided with suitable canopy to prevent unwarranted trippings due to moisture ingress.

At present, PED is dependent on external agencies for carrying out testing of various electrical equipment & relays & protection oriented trouble

shooting. Steps may be taken to establish Standard Testing Lab and procurement of essential testing equipments to cater to all 230 kV substations

under its control.

PED informed that they had already initiated steps for Renovation & Upgradation (R&U) of grid stations in Pondycherry region (230/ 110 kV Villianur

SS & 230/ 110 kV Bahour SS) under PSDF funding, covering most of the above works. In this regard, PED is requested to furnish detailed scope of

the works included in proposed R & U works.

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auditated


Constituent)


Constituent)

1 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for numerical relays for main protections of feeders (230 kV

as well as 110 kV) and trasformers against the existing static relays. The work is

scheduled to be completed by June 2019.

Pending

2 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Control & Relay Panels installed with static relays are proposed to be replaced with

new control panels installed with numerical relays under the project of Upgradation of

existing static relays and replacement of sub-station equipments at 230KV Villianur and

Bahour Auto Sub-Station at the cost of Rs.10,56,16,191/- through PSDF funding.

Tendering process for award of work on labour contract basis for the above said work

is almost over and waiting for the approval of Puducherry Government to place order

at the lowest tenderer.










Pending

3 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:











execution of work, Z4 (reverse) will be provided in all distance relays of 230KV and

110KV feeders.

Pending

2) 230/ 110 kV Bahour SS [10 - 12 July, 2017]


It is observed that main protections of feeders (230 kV as well as 110 kV) and trasformers are being provided from static relays. Steps may be taken

to replace the same with suitable numerical relays.

Directional O/C & E/F protections to be provided for 230 kV & 110 kV feeders where Main-II is not provided; Directional E/F protection to be provided

for 230 kV & 110 kV feedes where Main-I & Main-II are provided

Z4 (reverse) is to be provided in all distance relays of 230 kV & 110 kV feeders

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Constituent)

4 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:











execution of work, Z2 and Z3 (reactive & resistive) reaches & time settings will be set

in line with Ramakrishna Committee guidelines.

Pending

5 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:











execution of work, Auto-reclosure dead-time and reclaim-time for 230 kV feeders will

be revised to 1 sec and 25 sec respectively.

Pending

6 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:










Auto Sub-Stations under PSDF funding at the cost of Rs.4,47,42,293/-At the time of

execution of work, Power Swing Philosophy (Z1 --> Unblock; Higher Zones --> Block

for 2 sec) will be adoped unfiromly across all 230 kV feeders.The work is scheduled to

be completed by June 2019.

Pending

7 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:






Load encroachment feature will be enabled in 230 kV & 110 kV feeders during the time

of forthcoming relay testing programme.

Pending

8 Mail dated 30.01.2018 & 13-03-2018 & 10.07.2018:

Co-ordination of Protection & Communication wing of TAN TRANSCO Limited,

Villupuram has been requested to bring the 230KV and 110KV Bus Bar Protection

scheme into service.


Exsiting busbar protection relays of 110KV and 230KV Buses have been delcared as

obsolete by Original Equipment Manfacturer. A Work Order has already been placed at

M/s.GE T&D India Limited, Chennai vide Work Order No.784/ED/SE-cum-

HOD/EHV/PLCC&Lines/F-PSDF/2018-19, dated 22/10/2018 towards Design, Supply,

Erection, Testing & Commissioning of 230KV & 110KVC & R Panles, SAS and PLCC

equipments at 230/110KV Villianur and Bahour Auto Sub-Stations under PSDF funding

at the cost of Rs.4,47,42,293/- wherein provision has been given for numerical bus

bar protection realys for both 230KV and 110KV Buses.The work is scheduled to be


Pending

Load encroachment feature may be appropriately kept enabled in 230 kV & 110 kV feeders.

It is observed that busbar protection relays have been provided for both 230 kV & 110 kV buses. However, the same have been kept out of service

since commisssioning. PED shall take steps to put these into operation.

Z2 and Z3 (reactive & resistive) reaches & time settings were observed to be not in line with Ramakrishna Committee guidelines, which may be

reviewed appropriately.

Auto-reclosure dead-time and reclaim-time for 230 kV feeders may be revised to 1 sec and 25 sec respectively. Accordingly Pole Discreancy time-

delay may be kept at 1.5 sec.

Power Swing Philosophy (Z1 --> Unblock; Higher Zones --> Block for 2 sec) is to be adoped unfiromly across all 230 kV feeders.

65/95

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9 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:






During the next annual relay testing programme on 230 kV Pondy feeder, POR will be

enababled in place of the existing PUR.

Pending

10 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

One set of existing aged 110Volt Station Battery has been replaced with a new battery

bank during the last week of January 2018. Action has been initiated for necessary

wiring to segregate Main-I and Main-II Protection to fed from different DC source.











work will see the Main-I & Main-II protections or Main & back-up protections of

feeders are fed from different DC supplies.The work is scheduled to be completed by

June 2019.

Pending

11 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for REF protection for 80 MVA, 230/ 110 kV ICT-1 & ICT-2.

The work is scheduled to be completed by June 2019.

Pending

12 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for directional O/C protection for 80 MVA, 230/ 110 kV ICT-1

& ICT-2. The work is scheduled to be completed by June 2019.

Pending

For 230 kV Pondy feeder POR may be used in place of the existing PUR.

Steps to be taken to ensure that Main-I & Main-II protections or Main & back-up protections of feeders are fed from different DC supplies.

REF protection to be provided for 80 MVA, 230/ 110 kV Transformers -1 & 2.

Directionality to be provided for O/C protection of 80 MVA, 230/ 110 kV Transformers -1 & 2.

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13 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for directional E/F protection for 80 MVA, 230/ 110 kV ICT-1

& ICT-2. The work is scheduled to be completed by June 2019.

Pending

14 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for Overflux protection for 80 MVA, 230/ 110 kV ICT-1 & ICT-

2. The work is scheduled to be completed by June 2019.

Pending

15 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

One set of existing aged 110Volt Station Battery has been replaced with a new battery

bank during the last week of January 2018. Action has been initiated for necessary

wiring to segregate Group-A and Group-B Protection of Transformer fed from different

DC source.











work will see Group-A & Group-B protections or Main & back-up protections of

Transformers are fed from different DC supplies.The work is scheduled to be


Pending

Directional E/F protection to be provided for 80 MVA, 230/ 110 kV Transformers -1 & 2.

Overflux protection to be provided for 80 MVA, 230/ 110 kV Transformers -1 & 2.

Steps to be taken to ensure that Group-A & Group-B protections or Main & back-up protections of Transformers are fed from different DC supplies.

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16 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for GPS based time-synchronization equipment for time-

synchronizing various 230 kV & 110 kV protection relays. The work is scheduled to be


Pending

17 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for DR's with facility for automatic fault record downloading

to a central PC/ server.The work is scheduled to be completed by June 2019.

Pending

18 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:














provision has been given for Stand-alone Event Logge. The work is scheduled to be


Pending

19 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:





that DPR, provision has been given to provide Line CVTs in all phases for all 230KV

Lines..


e-tender has been called for the work of Design, Manufacture, supply, erection, testing

& commissionin gof 230 & 110KV switch yard equipments including earthing and

support structures at 230/110KV Bahour Auto Sub-Station under PSDF where in

provision has been given for providing Line CVTs in all phases.

Pending

Steps may be to taken provide DR's with facility for automatic fault record downloading to a central PC/ server.

Stand-alone Event Logger may be provided.

Line CVT's to be provided in all phases for all 230 kV lines.

GPS based time-synchronization equipment may be provided for time-synchronizing various 230 kV & 110 kV protection relays.

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20 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:





that DPR, provision has been given to provide Surge Arrestors for 230KV feeders at

gantry entry point.


Will be included in the proposed R&M works.

Pending

21 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Budgetary offer has been called for from a reputed contractor for arresting oil leakage

observed in the Transformers. Work will be commenced shortly on obtaining

expenditure sanction from the competent authority on the estimate prepared with the

rate offered by the contractor.


A Work Order has been placed at M/s. ASEA Power Electricals, Chennai - 600 019 vide

Order No.05/ED/EE-AUTO SS/AEE-M/BASS/F-11/2018-19, DATED22/10/2018 for

carrying out the work of transformer oil replacement and arresting of oil leakage in

80MVA Auto TransformerI at 230/110KV Bahour Auto SS at the cost of Rs.5,77,610/-

Approval of the Competent Authority has also been obtained for availing shutdown on

the said transformer between 21.01.2019 and 04.02.2019 to carry out the abvoe said

work. Enquiry has been floated for inviting quotations to carry out transformer oil

replacement and arresting of oil leakage in 80MVA Auto TransformerII at 230/110KV

Bahour Auto SS.

Pending

22 Mail dated 30.01.2018 & 13-03-2018:

the recommendation of Protection Audit Team, a Detailed Project Report at the cost of

Rs.14,85,42,653.21 has been prepared to replace the existing aged equipments and

provide additional equipments at 230KV Villianur and Bahour Auto Sub-Station and


that DPR, provision has been given to provide fire protection system to 80MVA Auto

Transformer-I&II.






that DPR, provision has been given to provide fire protection to transformers.









Pending

Surge Arrestors to be to be provided for 230 kV feeders at gantry entry point.

Oil leakage is being observed in both 80 MVA, 230/ 110 kV Tranformers. Suitable action may be taken to arrest the same.

It is observed that existing 80 MVA transformers have not been provided with fire protection. Steps may be taken to provide the same in accordance

with relevant standards.

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23 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

OEM M/s.Crompton Greaves Limited has been requested to offer rate to bring back the

230KV Bus Coupler Breaker into service. As per the recommendation of Protection

Audit Team, a Detailed Project Report at the cost of Rs.14,85,42,653.21 has been

prepared to replace the existing aged equipments and provide additional equipments

at 230KV Villianur and Bahour Auto Sub-Station and sent to higher authority to obtain

sanction under PSDF funding. (copy enclosed). In that DPR, provision has been given

to provide attendant CTs to make way to two-zone busbar protection.


e-tender has been called for the work of Design, Manufacture, supply, erection, testing

& commissionin gof 230 & 110KV switch yard equipments including earthing and

support structures at 230/110KV Bahour Auto Sub-Station under PSDF where in

provision has been given for replacing the existing 230KV & 110KV Bus Coupler

Breakers with new breakers.

Pending

24 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Action has been initiated to segregate the wiring for extending supply from DC1 and

DC2 to trip coil of 230KV and 110KV Breakers.







execution of work, extension of supply from DC1 and DC2 to trip coils of 230KV and

110KV feeders will be ensured.

Pending

25 Mail dated 30.01.2018:

In addition to the existing 48Volt PLCC battery, one more 48Volt PLCC Battery bank

has been erected and commissioned during the last week of January 2018. Wiring will

be done to segregate Source-1 & II.

Mail dated 13.03.2018 & 10.07.2018:

In addition to the existing 48Volt PLCC battery, one more 48Volt PLCC Battery bank

has been erected and commissioned as a redundant DC supply for communication

during the last week of January 2018 with requisite segregation in wiring.

Complied

26 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Action has been initiated to earth all gantry towers (metallic structures) including

lightning mast.


Action has been initiated to earth all gantry towers (metallic structures) including

lightning mast.

Pending

27 Mail dated 30.01.2018:

Action has been initiated to Equipment labeling for proper phase-sequence

Mail dated 13.03.2018 & 10.07.2018:

The work of Equipment labeling for proper phase-sequence was completed on

13.03.2018.

Complied

28 Mail dated 30.01.2018:

Action has been initiated for Earthing of equipment including door-to-panel earthing.

Mail dated 13.03.2018 & 10.07.2018:

The work of Door-to-panel earthing in various switchyard marshalling panels was

completed on 13.03.2018.

Complied

29 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Suitable canopy has been fabricated and kept on hand awaiting for shutdown to

provide over Buchholz relays


Complied. Buccholtz relays were kept provided with suitable canopy from 31.08.2018

to prevent unwarranted trippings due to moisture ingress.25.09.2018

Pending

Equipment labeling for proper phase-sequence may be provided.

Door-to-panel earthing in various switchyard marshalling panels to be properly ensured.

Buccholtz relays may be provided with suitable canopy to prevent unwarranted trippings due to moisture ingress.

It is observed that 230 kV & 110 kV Bus-Coupler breakers are not in working condition, and have been kept out of service. Also they have no

attendant CT's. PED may therefore take steps to replace them with attendant CT's to make way for two-zone busbar protection.

Segregation in wiring for extending supply from DC1 and DC2 to trip coils of 230 kV & 110 kV feeders to be carried out.

Redundant DC suppy for communication (48 V) application to be provided with requisite segregation in wiring.

All gantry towers (metallic structures) including lightning masts to be earthed properly as per relevant standards.

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30 Mail dated 30.01.2018:

Exploring all the possible ways to provide another dedicated redundant AC auxiliary

supply from nearby 110/22KV Sub-Station which is being fed by other 230KV Sub-

Stations.

Mail dated 13.03.2018 & 10.07.2018:

Division-EHV of this department has been requested vide Lr. No.714/Ed/EE-Auto

SS/AEE-M-VASS/F-4/2017-18, dated 27.02.2018 (Copy enclosed) to explore the

possibilities of arranging an alternate 22KV supply fed from 110/22KV Sub-Stations

those are either fed from 230KV Villianur Auto SS or 230KV Thondamanatham Auto SS

for the existing 22KV/440V Distribution Transformer installed in the campus of 230KV

Bahour Auto SS, presently being fed by 22KV Pandasozhannlur feeder from 110/22KV

Bahour SS.


Survey for providing another dedicated reduntant AC auxilliary supply feeder has been

completed and is now at the stage of preparation of necessary estimate.

Pending

31 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

DC earth leakage being observed in the battery charger will be attended in the

forthcoming total shutdown. Replacement of existing DC Distribution Panels have been

included in the DPR.


Tried to attend the issue two times with the department's work source during the time

of total shutdown but could not succeeded with. It is proposed to approach the issue

with the experts during the time of next total shutdown.

Pending

32 Mail dated 30.01.2018:





that DPR, provision has been given to provide chemically treated PCC flooring, and

then covering it with suitable blue metal spreading in switchyard area.

Mail dated 13.03.2018 & 10.07.2018:

Vegetation & weeds grown in the switch yard area were manually cleared and now the

switch yard is kept clean. However, as a permanent measure, Detailed Project Report

at the cost of Rs.14,85,42,653.21 has been prepared to replace the existing aged

equipments and provide additional equipments at 230KV Villianur and Bahour Auto Sub-

Station and sent to higher authority to obtain sanction under PSDF funding. (copy

enclosed). In that DPR, provision has been given to provide chemically treated PCC

flooring, and then covering it with suitable blue metal spreading in switchyard area.


Agaist the request of Puducherry Electricity Department, a thorough survey has been

completed by Public Works Department, Puducherry towards laying of chemically

treated PCC flooring, and then covering it with suitable blue metal spreading in

switchyard area. They are under the process of preparing necessary estimates.

Pending

33 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:





that DPR, provision has been given to replace the existing dilapidated gantry &

equipment supporting (RCC) structures with G.I. lattice / tubular structures.


Will be included in the proposed R&M works.

Pending

At present AC auxiliary supply is being obtained from 22 kV Bahour (Pandasozhanallur) feeder from nearby 110/ 22 kV Bahour SS. Since this 110/ 22

kV SS is being fed from the present 230/ 110 kV SS, in the event of supply failure at the latter, the former will also lose supply. PED shall take steps

to provide another dedicated redundant AC auxiliary supply feeder.

DC earth leakage is being observed in both 110 V DC Sources. Also the corresponding DC Earth-fault relays in soruce end DCDB panels are observed

to be not in working-condition. Steps shall be taken to rectify the same at the earliest.

Vegetation & weeding is observed in switchyard area. Steps may be taken to provide chemically treated PCC flooring, and then covering it with

suitable blue metal spreading in switchyard area.

It is observed that most of the existing gantry & equipment supporting structures have been of RCC. PED may take steps to replace them with

suitable lattice/ tubular structures when R & M works for the substation are propsoed.

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34 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Actions have been initiated for Testing of various relays and measurement of earth-

resistance values for various earth-pits periodically as per relevant standards and

record them properly


Action has been initiated to maintain records of relay testing values and measurement

of earth resistance values of earth pits.

Pending

35 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Protection and Communication wing of TAN TRANSCO Limited, Villupuram has been

requested to furnish the existing relay settings for future reference.


Complied. Relay settings have been obtained from Tamil Nadu Transmission

Corporation Limited and kept at Sub-Station

Pending

36 Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:






Pending

37 Mail dated 30.01.2018:



enclosed)

Mail dated 13.03.2018 & 10.07.2018:



enclosed)

Complied

Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Fault level of the station has been requested from EHV division of this department.

Details will be furnished as soon as received from the said division.


Fault level at 230KV level (3Ph): 3654.16MVA;

Fault level at 110KV level (3ph):2998.16MVA.

---------- Completed.

Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Protection and Communication wing of TAN TRANSCO Limited, Villupuram has been

requested to furnish the existing relay settings. Relay settings will be furnished as

soon as received from the said corporation.


Adopted Relay Settings furnished --- Completed

Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Details are being collected from the source available at 230KV Bahour Auto Sub-

Station. Details will be furnished shortly.


Details of Relay Testing carried out furnished --- Completed

Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Action has been initiated to measure the Earth-mats and Earth-Pits value.

Measurements will be submitted shortly.


Will be submitted shortly.

PED informed that they had already initiated steps for Renovation & Upgradation (R&U) of grid stations in Pondycherry region (230/ 110 kV Villianur

SS & 230/ 110 kV Bahour SS) under PSDF funding, covering relay & control panel replacement works. In this regard, PED is requested to furnish

detailed scope of the works included in proposed R & U works for the 230/ 110 kV substation.

PED has not provided the following data as part of protection audit:

(i) Fault level of the Substation for 3-ph-Ground and 1-ph-Ground faults at both 230 kV and 110 kV levels

(ii) Adopted Relay Settings (given by Head Quarters/ Corporate Office and implemented in field)

(iii) Details on Periodicity of Relay Testing and latest Relay Test Reports

Testing of various relays and measurement of earth-resistance values for various earth-pits should be undertaken periodically as per relevsnt

standards, and records properly maintained.

It is observed that relay settings for various protection relays have been set by TNEB at the time of commissioning. However, records relating to the

same have not been made available to PED. Steps may be taken (by PED/ TNEB) to maintain proper records w.r.t. Implemented relay settings at

Substation level.

At present, PED is dependent on external agencies for carrying out testing of various electrical equipment & relays & protection oriented trouble

shooting. Steps may be taken to establish Standard Testing Lab and procurement of essential testing equipments to cater to all 230 kV substations

under its control.

(iv) Details of Measurement of Station Earth-Mat & Earth-Pits

38 Pending

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Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Will be submitted shortly.


AC Supply Changeover Scheme furnished ------ Completed

Mail dated 30.01.2018, 13.03.2018 & 10.07.2018:

Details have been called for from TAN TRANSCO Limited. Will be submitted shortly on

receipt of the same.


Details of 110KV CT ratios available and adopted are attached herewith. CT ratio error

will be submitted shortly after conducting CT ratio tests on the said CTs.


Equipment/

System auditated


Constituent)

1 General In pole 1 Trip Circuit Supervision relays are not available in the circuit. However Trip Circuit

Supervision is being monitored by RPC (Reactive Power Control)

Mail Dated 05-02-2018:

Pole-1 RPC system trip circuit supervision relays are installed in the month Dec-2017 &

presently in service.

Complied

2 General HVDC pole - 1 & 2 Auxiliaries supply (33 kV) are being fed from ICT-2 (tertiary) only. In the

event of failure of auxiliary supply DG set 1 & 2 respectively will feed the supply to the

Auxiliaries.


Aux supply provision from ICT-1 (Second Aux supply) comissioned. Automatic supply

changeover scheme for Pole-1 has implemented. In the event of failure of auxiliary

supply DG set feed the supply to the auxiliries.

Order placed for retrofitting of LT brakers in Auxiliary system & installation will

complete by 30-April-2018.

Complied

3 General HVAC S/S Auxiliaries supply (33 kV) are being fed from APTRANSCO feeder only. In the

event of failure of auxiliary supply DG set will feed the supply to the Auxiliaries.


Presently HVAC S/S Auxiliaries supply (33 kV) are feeding from APTRANSCO feeder

only. In the event of failure of auxiliary supply DG set is feeding the supply to the

Auxiliaries.


02 Nos 33kV Feeders emanating from Paravada and Chinnagantayada are available for

auxilliary supply of Gajuwaka HVAC. In the event of failure of auxiliary supply DG set

is feeding the supply to the Auxiliaries.

Complied

4 General HVAC DG set starting by manual only. Mail Dated 05-02-2018:

HVAC DG set is presently starting by manual in case of supply failure. The same shall

be changed to auto & will completed in NTAMC sworks by October-2018.


The LT breakers are being retrofitted wth New LT CBs and DG-LT auto changeover

shall be implemented by Apr'2019.

Pending

5 General Oil leakage was observed from the line reactor of Vijayawada line Mail Dated 05-02-2018:

Oil leakages of Vijayawada L/R rectified in the month of April-2016.

Complied

(v) AC Supply Changeover Scheme

(vi) Details of 110 kV CT's Ratios and Errors

PGCIL (SR-I)

1) 400 kV & HVDC Gajuwaka SS [28-30 December, 2015]

38 Pending

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6 General Stub Protection time delay is kept as 100 ms. Mail Dated 05-02-2018 & 24-07-2018:

As per POWERGRID, Corporate recommendations Stub prot settings are adopted as

2.0 A ( Sec) if CT ratio is <=1000A & & time delay 100 msec. For others 1.5 Amp.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. PGCIL (SR-

I) was clarified that the adopted settings for Stub Protection are in direct

violation of Regulation 3 (e) of CEA (Grid Standards) regulations, 2010, and

asked to revise them in line with Ramakrishna Committee guidelines of I >

250% with time delay of 50 ms.


The time delay of 100msec is kept to avoid mal-operations in case of inadvertent

isolator open status event when the line is charged, and some other downstream line

has a fault. The time delay of 100msec gives time for downstream line fault to get

cleared.

The issue was discussed in PCSCM-81 meeting held on 24.01.2019. PGCIL

(SR-I) was clarified that the adopted settings for Stub Protection are in

direct violation of Regulation 3 (e) of CEA (Grid Standards) regulations,

2010, and asked to revise them in line with Ramakrishna Committee

guidelines of I > 250% with time delay of 50 ms.

Pending

7 General For 400 kV Kalpakka Line-1, Circuit Breaker Pole discrepancies kept as 1.0 s Mail Dated 05-02-2018:

400 kV Kalpakka Line-1, Circuit Breaker Pole discrepancies changed to 2.5 sec from 1.0

sec in Janaury-2016.

Complied

8 General For 400kV Kalpakka line 1& line 2,

Main- 1 relay:

Reverse Zone is not available in REL-100.

Zone- 3 time delay is observed as 1.5 sec.

Stand alone Auto reclosure in off condition.

Relay is not time synchronized with GPS.

Main- 2 relay:

Reverse Zone setting time kept as 2s.

Over Current protection enabled.

DEF is not provided.

Stand alone Auto reclosure in off condition.

Relay is not time synchronized with GPS.


Informed to APTRANSCO for necessary action & 400kV Gazuwaka-Kalpaka-1&2 line

settings modified as per Ramakrishna Committee recommendations in December-

2017. However the same relays will be retrifitted with LDP relays by APTRANSCO. In

71st PCSC meeting APTRANSCO informed that the LDP relay installation will complete

by April-2018.


Pending with APTRANSCO.


The relays were retrofitted with LDPs by M/s APTRANSCO using PSDF.

Complied


Equipment/ System

auditated


Constituent)

2) 400/ 220 kV Gooty SS [12th, 13th and 15th February, 2016]

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Constituent)

1 400kV Control and

Protection Panels

For 400 KV Busbar protection (RADSS of ABB make), one main Bus bar protection scheme

for each Bus 1 & Bus 2 available and Check Zone protection is not available . Redundant Bus

bar protection or Check zone shall be considerd.


In place of Main & Check Zone , In ABB make RADSS B/B protection relay Start &

Differential features are available.

IN RSTPP, CTP-1 Transmission systems Bus Bar protection scheme was envisaged as

per CEA/CBIP guidelines then existing.

Retrofitting of existing B/B schme with redundant BB protection shall be proposed

under ADD CAP.


Bus Bar protection scheme was envisaged as per CEA/CBIP guidelines then existing.

The RADSS Busbar protection has main and Check features.

However, since Busbar protection is 25years old, proposal for retrofitting of busbar

protection is being taken up with our CC and CEA/CERC. If CEA/CERC agrees for add-

cap, the retrofitting shall be completed by Mar-2019.


I) was asked to take steps to comply with the remark at the earliest.



The RADSS Busbar protection has inbuilt main and Check features.

However, since Busbar protection is 25years old, the same is being retrofitted with

numerical busbar protection under Add-Cap and shall be completed by Mar'2019.

Pending

2 DEF protection is enabled in Main-1 of 400kV Nelamangala & Kurnool AP line. However

inspite of availability of DEF protection in Main 2 (Ohmega) Distance relays is not enabled.

Powergrid informed that settings adopted for Ohmega relay is as per CC Recommendation


We have observed mal-operation of DEF protection in Omegha relays & hence the DEF

feature disabled.

Proposal for retrofitting of Omegha relay with latest numerical relay has been

approved and is under tendering stage. The same shall be retrofitted by October-2018.


Proposal for retrofitting of Omegha relay with latest numerical relay has been

approved and is under tendering stage. The same shall be retrofitted by Dec-2018.


Old Omegha Relay was retrofitted with Micom P444 Relay in Nov'2018

Complied

3 Kurnool PG Line reactor and Bus reactor RWTI meters placed in control panel are not in

working condition.


Rectified & faulty meters were replaced with new meters On 05-05-2017.

Complied

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auditated


Constituent)

4 Stub protection current set and time delay set as I> 150% and 100ms against the

recommendeed setting of I>250% and time delay of 50ms by M/S Tractebel.Powergrid

informed that settings adopted as per CC Recommendation

Mail Dated 05-02-2018 & 24-07-2018:

As per POWERGRID, Corporate recommendations Stub prot settings are adopted as

2.0 A ( Sec) if CT ratio is <=1000A & & time delay 100 msec. For others 1.5 Amp.


I) was clarified that the adopted settings for Stub Protection are in direct

violation of Regulation 3 (e) of CEA (Grid Standards) regulations, 2010, and

asked to revise them in line with Ramakrishna Committee guidelines of I >

250% with time delay of 50 ms.





cleared.






Pending

5 AC Distribution It was observed that one 33kV feeder is available for auxilliary supply of station.

POWERGRID informed that second redundant AC supply source from ICT-II tertiary winding

is under progress.


On 29-05-2016 second redundant AC supply source from ICT-II tertiary winding is

Charged.

Complied

6 DC Distribution For 400kV bus bar protection panel, 2 DC sources are available with selector switch only.

Automatic changeover is not provided.


IN RSTPP, CTP-1 Transmission systems Bus Bar protection scheme was envisaged as

per CEA/CBIP guidelines then existing.

Retrofitting of existing B/B schme with redundant BB protection shall be proposed

under ADD CAP.


Automatic changeover of DC source was provided in retrofitting of existing B/B

schme with redundant BB protection & shall be completed by the end of Mar-2019.



However, since Busbar protection is 25years old, the same is being retrofitted with

numerical busbar protection under Add-Cap and shall be completed by Mar'2019.

Pending

7 Battery voltage measured on the date of audit is as below:

P-N(v) P-E(v) N-E(v)

220V Battery set 1 : 225.5 98.2 -127.0

220V Battery set 2 : 233.3 96.8 -136.0

48V Battery set 1 : 53.6 NA 51.9

48V Battery set 2 : 52.4 NA 53.0


Battery voltage measured on 03.02.2018 and is as below:

P-N(v) P-E(v) N-E(v)

220V Battery set 1 : 218.6 + 115.9 -102.5

220V Battery set 2 : 243.0 + 122.4 -120.4

48V Battery set 1 : 48.8 NA -48.5

48V Battery set 2 : 52.8 NA -52.4

Complied


Equipments

Lightning protection ( LAs) Earthing is not done as per standards/ NFPA for ICT-1 & 400kV

Gooty-Kurnool PG Line Reactor. LAs (system ) earthing are not connected to earth electrodes

directly instead it is connected through equipment earthing. It should be modified similar

to other bays.


LA Earthing was modified during AMP S/D of GOOTY-KNL PG L/R On dt 27.06.2017 &

During AMP S/D of ICT-1 On dt 10.06.2017

Complied


Constituent)

3) 765/ 400 kV Nellore PS [19 - 20 June, 2017]


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Constituent)

1 Letter Dated 19-AUG-2017:

The reaches/ Pickup/ Drop off of all the numerical relays are being checked on 04

yearly basis as per powergrid preventive maintenance procedures. However, DC logics,

Trip Logics, Auto-reclosure, O/V, Stub functions etc. are being tested/checked during

every AMPs and oppurtunity shutdowns.


All numerical relays were tested at NPS during last 6 months as per POWERGRID

maintenance plan.

Complied


Implimented as per POWERGRID philosophy and Ramakrishna Committee

recommendations.


I) was asked to take steps to comply with the remark at the earliest. It was

also clarified that if required they are at liberty to increase current setting

and/ or time settings (say, 1.1 sec) suitably.


No such protection is envisaged in the Model relay setting guidelines and Ramakrishna

Committee recommendations.

The issue was discussed in PCSCM-81 held on 24.01.2019. PGCIL (SR-I) was

asked to take steps to comply with the remark at the earliest. It was also

clarified that if required they are at liberty to increase current setting and/

or time settings (say, 1.1 sec) suitably.

Pending


Intentional Delay of 100 msec (with POR) provided for zone-1 of Gooty-1 &2 feeders in

view of FSC at Gooty substion.

Complied


Measurement principle of each relays (different manufacturers) for Phase- Earth

Resistive reaches are different and hence the resistive reaches (Phase-Earth) for

REL670/P444/7SA522 Relays kept different.

Complied

5 Complied


Constituent)

1 Mail Dated 24-07-2018:

Provided. Work completed.

Complied

2 Mail dated 21.01.2019:

As per Ramakrishna Committee recommendations, LDP was envisaged as Main-1

protection with back up distance feature. Provision of LDP protection as Main-2 may

please be approved by SRPC under Add-Cap.

Pending

4) 765/ 400 kV Maheshwaram (GIS) SS [8 - 9 February, 2018]


Colour coding for phase identification of breakers may be provided in 765 kV & 400 kV GIS Halls.

For 400 kV Maheshwaram (PG) - Maheshwaram (TS) lines 1 & 2, presently Line Differential Protection (LDP) and Distance Protection (DP) have been

provided as Main-I and Main-II respectively. Since they are very short lines, steps shall be taken to provide LDP as Main-II also.

As most of the numerical relays have completed 4-years of in-service operation, comprehensive testing of the same may be carried out.



delay of (say) 500 msec.

It is observed that Zone-1 time delay for Gooty lines 1 & 2 is kept as 100 msec, which may be clarified/ reviewed.

Z2, Z3 and Z4 Resistive reaches for Ph-G faults for Main-I & Main 2 have been found to be kept differently on 400 kV NCC lines 1 & 2, 400 kV Gooty

lines & 765 kV Kurnool lines, which may be reviewed.

PLCC dB level (signal strength) measurements are being done on yearly basis.

77/95

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Equipment/ System

auditated


Constituent)

3 Mail dated 21.01.2019:

The present scheme fulfils the criteria of segregation of trippings in two groups, Group-

A and Group-B. All the reliability conditions as per CBIP guidelines on protection

system are being fulfilled.

The issue was discussed in PCSCM-81 held on 24.01.2019. The importance of

the recommendation in adding more reliability for a substation such as 765/

400 kV Maheshwaram-PG was emphasized. In this regard, PGCIL (SR-I)

informed that they were in the process of providing back-up impedance

protections for the ICT's for better reliability, hence requested to drop the

Item. Accordingly, PCC forum agreed to drop the Item.

DroppedIn 765/ 400 kV ICTs - 1 & 2, it is noted that all Group-A protections containing the primary Differential and the secondary DOCE (HV) have been

provided from one relay. Similarly, all Group-B protections containing the primary REF and the secondary DOCE (LV) have been provided from

another relay. Since, there is no duplication of these group protections, steps shall be taken to provide the primary and secondary protections of each

group from different relays for better reliability.

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Equipment/ System

auditated


Constituent)

4 Mail Dated 24-07-2018:

Tertiary T/F is ready & waiting for TSTRANSCO/TSSPDCL approval.


Tertiary T/F is ready & waiting for TSTRANSCO/TSSPDCL approval.

Pending

5 Mail dated 21.01.2019:

No such protection is envisaged in the Model relay setting guidelines and Ramakrishna

Committee recommendations.

The issue was discussed in PCSCM-81 held on 24.01.2019. Explaining that

the recommendation is about clearing a Ph-Ph fault under VT fuse fail

conditions, PGCIL (SR-I) was asked to take steps to comply with the remark

with a suitable delay such as 1.1 sec (instead of 600 msec) at the earliest.

Pending

6 Mail dated 21.01.2019:




cleared.






Pending

7 Mail dated 21.01.2019:

The relay settings are being calculated by our CC-Engg. The calculation sheets may

please be collected from CC-Engg/AM.

The issue wwas discusssed in PCSCM-81 held on 24.01.2019. PGCIL (SR-I)

was asked to comply with remark at the earliest.

Pending


Equipment/ System

auditated


Constituent)

1 General Zone 3 and reverse zone resistive reach settings are differently seted in the relays Mail dated 30.01.2018:

The Zone 3 Settings kept as 1 Sec, in case it is crossing the next voltage level the

same was kept as 1.5Sec.

Complied

2 General Zone 4 reach should be set to cover 50% of shortest line connected in Hosur SS ( existing



Presently kept as 20% of Protected line.


Kept as 20% of Protected line which will cater the functional requirement as per the

organizational Philosophy.


Zone 4 is meant for reverse bus bar faults, which can be taken care by providing the

20% of the protected line in line with the organization philosophy. As the same is

meeeting the functional requirement the point may be treated as closed.

The issue was discussed in PCSCM-76 held on 26.07.2018 & PCSCM-81 held

on 24.01.2019 PGCIL (SR-II) was asked to comply with the remark at the

earliest so as to be in line with the Ramakrishna Committee guidelines.

Pending

PGCIL (SR-II)

1) 400 kV Hosur SS [9-11 December, 2015]

Commissioning of Aux. Supply from ICT-2's Tertiary as redundant auxiliary supply may be expedited.



delay of (say) 600 msec.

Stub Protection Timing, which is presently kept as 100 msec may be suitably revised to 50 msec.

Calculation Sheet(s) showing protection settings calculation for all feeders and transformers may be furnished.

79/95

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Equipment/ System

auditated


Constituent)

3 General PSB for 400kv is in line with guide line the same is not respected on 230kv lines (all zone

are blocked)


For 220/230kV lines all zones are blocked for PSB.


For 220/230kV lines all zones are blocked for PSB as per the organizational

Philosophy.


For 220/230kV lines all zones are blocked for PSB.where as in 400kV is allowed for

tripping as per the organizational Philosophy. Based on the operational experinece

the settings found to be intact. Hence the same shall be treated as closed.


on 24.01.2019. PGCIL (SR-II) was asked to keep PSB blocked for all Zones

except Zone-1 with an unblocking time delay of 2 sec for 230 kV feeders

also.

Pending

4 General STUB should be set to 50ms ( existing settings are 100ms) Mail dated 30.01.2018:

Under Review


Kept as 100msec of Protected line which will cater the functional requirement as per

the organizational Philosophy. In case of inadvertant initiation, the line might trip with

a delay of 50ms for even an outzone fault. 100ms is given to let the primary protection

of the downstream line operate.


Stub protection kept as 100msec for taking care of the unprotected area during line

isolator open condition. In case of inadvertant initiation due to momentary position

status, the line might trip for even an outzone fault.Hence 100ms is given to let the

primary protection of the downstream line operate. This is inline with the

Organizational philosophy and operational expeince. Hence the point may be treated

as closed.


on 24.01.2019. PGCIL (SR-II) was clarified that the adopted settings for

Stub Protection are in direct violation of Regulation 3 (e) of CEA (Grid

Standards) Regulations, 2010, and asked to revise them in line with

Ramakrishna Committee guidelines of I > 250% with time delay of 50 ms.

Pending


Equipment/ System

auditated


Constituent)

1 Zone 3 and reverse zone fault resistive reach settings are not matching and different w.r.t.

TE settings for all 400 and 230 KV feeders.


The Zone 3 Settings kept as 1 Sec, in case it is crossing the next voltage level the

same was kept as 1.5Sec

Complied

2 Zone3 time delay has been set as 1.5s instead of 1sec except Veeranam line Mail dated 30.01.2018:

The Zone-3 Settings kept as 1 Sec, in case it is crossing the next voltage level the

same was kept as 1.5Sec

Complied

2) 400 kV Tirunelveli SS [8th, 9th and 11th January, 2016]

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Equipment/ System

auditated


Constituent)

3 Zone 4 reach setting should be set to cover 50% of shortest line connected in Tirunelveli SS.

The existing setting for Zone-4 is different for all the 400kV & 220kV lines.


Presently kept as 20% of Protected line.


Kept as 20% of Protected line which will cater the functional requirement as per the

organizational Philosophy.


Zone 4 is meant for reverse bus bar faults, which can be taken care by providing the

20% of the protected line in line with the organization philosophy. As the same is

meeeting the functional requirement the point may be treated as closed.


on 24.01.2019. PGCIL (SR-II) was asked to comply with the remark at the

earliest so as to be in line with the Ramakrishna Committee guidelines.

Pending

4 PSB: For 400kv, all zones except zone-1 are blocked. For 220kV all zones are blocked. Mail dated 30.01.2018:

For 220/230kV lines all zones are blocked for PSB.


For 220/230kV lines all zones are blocked for PSB as per the organizational

Philosophy.


For 220/230kV lines all zones are blocked for PSB.where as in 400kV is allowed for

tripping as per the organizational Philosophy. Based on the operational experinece

the settings found to be intact. Hence the same shall be treated as closed.


on 24.01.2019. PGCIL (SR-II) was asked to keep PSB blocked for all Zones

except Zone-1 with an unblocking time delay of 2 sec for 220 kV feeders

also.

Pending

5 STUB protection timing should be set to 50ms. Existing setting is 100ms for 400kV Lines. Mail dated 30.01.2018:

Under Review.












as closed.






Pending

6 In 400KV Madurai line setting Zone-2 time delay is kept 0.5 sec instead of 0.35sec Mail dated 30.01.2018:

The time Descremenation depends on remote end lines co ordination. Accordingly 0.5

was kept.

Complied

81/95

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auditated


Constituent)

7 For 220kV lines dedicated speech available for Edamon DC lines only. Not available for all

other lines pertaining to TANTRANSCO (Udayathur, Kayathar, Veeranam, Sanganeri)


All the 220kV PLCC panels except Edamaon belongs to TANTRANSCO.


The Ownership of the line is pertaining to Tantransco.It was understood that as per

the organizational philosophy of TANTRANSCO, the speech panels were not provided.

Also Speech panels is being used for operational requirement only. The matter may

please be taken up in OCC and the same may please be treated as closed pertaining to

Protection Audit Compliance.


II) was asked to take steps to comply with the remark at the earliest.

Pending

82/95

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Equipment/ System

auditated


Constituent)

8 Following Protection & Data/speech channels used in 220kV Lines:

a) Edamon-1 line - 2protection+1data/speech

b) Edamon-2 line - 2protection; (Edamon 1&2 is DC Line)

c) Udayathur line - 1protection

d) Veeranam line - 1protection

e) Kayathar line - 1protection

f) Sanganeri line - 1protection


In line with Standard Philosophy for POWERGRID owned lines.

Complied


Constituent)

1 Mail dated 30.01.2018:

Reviewed. The Zone 3 Settings kept as 1 Sec, in case it is crossing the next voltage

level the same was kept as 1.5Sec

Complied

2 Mail dated 30.01.2018:

Reviewed and found in line with OEM recommendations

Complied

3 Mail dated 30.01.2018:

Reviewed and found correct

Complied

4 Mail dated 30.01.2018:

In Siemens relay Zone-5 is kept enabled

Complied


Constituent)

1 Mail dated 30.01.2018:

Reviwed. The Zone 3 Settings kept as 1 Sec, in case it is crossing the next voltage

level the same was kept as 1.5Sec.


The Timer will come into picture after the CVT fuse fail delay and is non directional.

Hence maximum time delay of Zones kept as 1.1sec which meets the functional

Requirement. Reducing the same might result in unsuccesful auto-reclosure.


VT fuse fail delay kept more than 0.5 sec as per the OEM recommendations and as per

the organizational philosophy. The relays has been tested and simulated with VT fuse

fail condition and found meeting the functional requirement. Hence the point may be

treated as closed

Complied

4) 400/ 220 kV Kozhikode SS [21-22 December, 2017]


3) 400 kV Alundur SS [16 December, 2016]


Zone-3 Time settings, which were presently kept at 1.5 sec to be suitably reviewed.

In Karaikudi Main-II relay, SOTF - Auto INIT, which was kept enabled, is to be reviewed

Resitive reaches for P-E faults for Zone-1 & Zone-2 of all feeders may be reviewed

Zone-5 of Main-I in Karaikudi feeders was kept enabled.

VT Fuse fail time delay which is presently kept as 1.1 sec may be suitably revised to say 0.5 sec

83/95

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Equipment/ System

auditated


Constituent)

2 Mail dated 30.01.2018:

Under Review.












as closed.






Pending

3 Mail dated 30.01.2018:

To be Provided.


As per the Recommendations, the same will be provided. The requiered hardware is

under procurement and shall be completed by April-18 end.


DC Supply Changeover provision has been made availble. In the event of failure of

One DC Source, through Selector Switch, Alternate DC can be extended.

Complied

4 Mail dated 30.01.2018:

Under Review.

Mail dated 13.02.2018 & 24.07.2018:

The Scheme studied in detail and compared with other few stations. As the trippings

are meant for different areas of protections ( 400kV side and 220kV side seperately)

and Gr-A and Gr-B relays were provided with different DC sources, the scheme is

found to be Ok, which is in line with POWERGRID Engineering Approval.

Complied

5 Mail dated 30.01.2018:

Under Review.


The Temporary ICT is provided to Cater the immediate load relief to KSEB as per KSEB

request, where common CB and CTs were utilized. Upon Commissioning of New ICT-3,

the ICT again shall be kept as Spare.


The temprary ICT ahs been taken out after commissioning of new ICT-3 in April-18.

Hence the point may be closed.

Complied

Stub Protection Timing, which is presently kept as 100 msec may be suitably revised to 50 msec.

DC supply selector switch may be provided in 220 kV BBP panel

Providing of DOCE (HV) protection and DOCE (LV) protections of ICT's from different DC Sources may be explored.

Presenly Differential, DOCE (HV) & DOCE (LV) protections have been provided in common to 315 MVA ICT-2 and 315 MVA ICT-3 as a temporary

arrangement. However, it is noted that with the commisssioning of new 500 MVA ICT in place of the existing ICT-3 (expected in 2 months), the

above protections would be made independent.

84/95

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Equipment/ System

auditated


Constituent)


Equipment/ System

auditated


Constituent)

1 Chandrapur 2 400 kV Isolator Marshalling

Box

Observed that Control Supply Fuse of Isolator (389B) was in removed condition. Mail dated 30.01.2018:

Control Supply fuse placed

Complied

2 Chandrapur 1 & 2 400 kV Protection Panel Observed that Auto Recloser of Circuit Breaker is kept off Mail dated 30.01.2018:

AR kept in service

Complied

3 Chandrapur 1 & 2 400 kV Main-I relay & Main-II

relay

Zone-4 timer is kept as 1.0 sec Mail dated 30.01.2018:

Z-4 time delay made to 0.5Sec

Complied

4 Chandrapur 1 & 2 400 kV Protection panel Over Voltage stage-II time delay is kept as 0 sec. Mail dated 30.01.2018:

OV St-II Time Delay kept at 0.1Sec

Complied

5 Chandrapur 1 & 2 400 kV Protection Panel Redundant Overvoltage Stage-I protection is not available. Mail dated 30.01.2018:

OV St-I protection made available

Complied

6 Chandrapur 1 & 2 400 kV Protection Panel Observed that STUB protection is not available. Mail dated 30.01.2018:

Will be implemented.


Will be implemented by 30.06.2018.


This will be implemented by 31.05.2019.

Pending

7 Warangal 400 kV Main-I relay (ABB

RAZFE)

Reverse Zone is not available. Mail dated 30.01.2018:

Relay retroftitted with numerical relay & reverse zone implemented

Complied

8 Warangal 400 kV Main-II relay Zone-3 time delay is kept as 1.2 s and Zone-4 time delay is kept as 1.0 s. Mail dated 30.01.2018:

Z-3 time delay changed to 1Sec & Z-4 time delay changed to 0.5Sec

Complied

9 Warangal 400 kV Protection panel Over Voltage stage-II time delay is kept as 0 sec. Mail dated 30.01.2018:


Complied

10 N.Sagar 1 & 2 400 kV Protection panel Over Voltage stage-II time delay is kept as 0 sec. Mail dated 30.01.2018:


Complied

11 N.Sagar 1 & 2 400 kV Main-II relay Observed that line Phase angle is kept as 75 degree (P-P) & 70 degree (P-N). Mail dated 30.01.2018:

Relay replaced with numerical relay & Phase angle changed to 75deg

Complied

12 N.Sagar 1 & 2 400 kV Main-I relay Observed that zone-4 time delay is kept as 1.0 s Mail dated 30.01.2018:

Z-4 time delay kept to 0.5Sec

Complied

13 N.Sagar 1 & 2 400 kV Main-II relay Observed that zone-3R time delay is kept as 1.3 s Mail dated 30.01.2018:

Z-3R (Rev zone)time delay kept to 0.5Sec

Complied

14 Gajwel 400 kv Main-1 relay Observed that zone-4 time delay is kept as 1.3 sec Mail dated 30.01.2018:


Complied

15 Gajwel 400 kv Main-I & II relay Observed that Zone-2 time delay is mismatching with main-I (500 ms) and main-II(400 ms)

relay.


Both Main-I&II Z-2 Time delay kept at 0.4Sec

Complied

16 Malkaram 400 kv Main-I & II relay Observed that time delay for Over Voltage Stage-II is mismatching with numerical relay and

static relay. Numerical relay time delay is 50 ms whereas in static relay is kept 0 sec.


OV St-II Time Delay kept at 0.1Sec for both numerical & static relays

Complied

17 Malkaram 400 kV Main-I& II relay Observed that zone-4 time delay is kept as 1.0 s Mail dated 30.01.2018:


Complied

NTPC

1) 400 kV Ramagundam STPS [18-20 February, 2016]

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auditated


Constituent)

18 Tie feeder 400 kV Control Panel Auto recloser reclaim time delay is kept as 2.5 sec and dead time delay is kept as 0.5 sec. Mail dated 30.01.2018:

AR Reclaim time kept at 25 Sec & dead time kept at 1Sec.

Complied

19 Hyderabad-3&4 400 kV Protection panel Observed that zone-4 time delay is kept as 1.0 s Mail dated 30.01.2018:


Complied

20 Hyderabad-3&4 400 kV Protection panel Observed that time delay for Over Voltage-II is mismatching with numerical relay and static

relay. Numerical relay time delay is 50 ms whereas in static relay is kept 100 sec.


OV St-II Time Delay kept at 0.1Sec for both numerical & static relays

Complied

21 Dichipally 400 kV Main-I relay Zone-4 time delay is kept as 1.3 s Mail dated 30.01.2018:


Complied

22 Dichipally 400 kV Main-I relay Over Voltage stage-II is not enabled. Mail dated 30.01.2018:

Relay replaced with numerical realy & OV St-II is enabled

Complied

23 Dichipally 400 kV Main-II relay Zone-4 time delay is kept as 1.3 s Mail dated 30.01.2018:


Complied

24 Dichipally 400 kV Main-II relay Over Voltage stage-I is not enabled. Mail dated 30.01.2018:

OV st-I presenlty in enabled condition

Complied

25 Dichipally 400 kV Control Panel Auto reclousre reclaim time delay is kept as 30 sec and dead time delay is kept as 0.939 sec. Mail dated 30.01.2018:

AR Reclaim time kept at 25 Sec & dead time kept at 1Sec.

Complied

26 Bus Reactor 400 kV Circuit Breaker

Marshalling Box

Circuit Breaker Pole Discreprency time delay is kept as 1.5 sec. Mail dated 30.01.2018:

PD timing set to 0.5Sec

Complied

27 Bus Reactor 400 kV Control Panel For LBB protection of Bus reactor, Current settings is at 0.05 In. Mail dated 30.01.2018:

Settings adopted are in line with our Engg recommendations. The FL CT secondary

current for reactor is 0.12A.

Complied

28 General Switchyard (ACDB) Auxiliary supply 415 V emergency feeder from DG set is kept in test

mode. The operation of changeover from normal supply to Emergency DG supply is done

manually.

Mail dated 30.01.2018 & 13.02.2018:

It is as per the scheme. Breaker presently kept in service position.


on 24.01.2019. NTPC was asked to prvodie auto supply changeover between

AC auxiliary supplies and DG source.

Pending

29 General All Isolators are operated from local. Mail dated 30.01.2018:

Remote operation is available for all isolators. As per the local practise & for extra

safety local operation is being done

Complied

30 General Auto recloser is enabled for main CB's only and disabled for all tie CBs. Mail dated 30.01.2018:

AR enabled for all Tie CB's

Complied

31 General Some of the Isolator Marshalling Boxes and CTs Junction Boxes in stage I installations are

found rusted.


Few are in rusted condition. Replacement being done in phased manner.


The Marshalling Boxes rust has been removed & suitably painted

Complied

32 General Cable for Manual Testing Solenoid is found disconnected in emulsifier system for Shunt

Reactor1.


Completed.

Complied

33 General Pressure gauge for Emulsifier system of Shunt Reactor 2 found not working. Mail dated 13.02.2018:

Will be replaced by 31.03.2018.


Pressure gauge replaced. ----Completed

Complied

34 General Electric fuses from control panel of emulsifier system of Shunt Reactor 1 and 2 are in

removed condition.


Fuses placed

Complied

35 General One of the PLCC II charger (48V) is giving alarm as rectifier fuse fail Mail dated 30.01.2018:

Rectified during Battery Load Test.

Complied

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Constituent)

36 General One of the Pressure gauge for Emulsifier system for Bus Reactor found defective. Mail dated 13.02.2018:

Will be replaced by 31.03.2018.


Pressure gauge replaced ---Complied

Complied

37 General In protection chnl I & II and speech chnl panels alarm indication for -Va is appearing Mail dated 30.01.2018:

Rectified

Complied

38 General Load enchrochment is not available in 400 kV feeders. However it was informed that the

resistive reach have been suitably calculated to take care of the same excluding the 400kV

Hyderabad line-3 & 4 (Main-2).


Load Encrochment is provided in Hyderabad Line-3,4(Main-2).

Complied

39 General STUB is enabled only for 400kV Malkaram, Warangal & Hyderabad 3 & 4 as instantaneous. Mail dated 30.01.2018:

Settings are as per our NTPC practice.


Exisitng is electromechanical Scheme. Will be implemented in numerical relay by

31.10.2018.


This will be implemented by 31.05.2019

Pending

40 General For Main-2 protection of 400kV Chandrapur line- 1 & 2 and Main-1 protection of 400kV

Nagarjunasagar line-1 & 2, Zone 1 & Zone 2 is Unblock condition for PSB.


Settings are as per our NTPC practice.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. PCSC

forum noted that if the observed remark is as per NTPC philosophy, then

there is an immediate & urgent need to change it so as to bring in line with

the Ramakrishna Committee guidelines, else their machines face the rsk of

permanent damage during power swings. NTPC was asked to keep PSB

blocked for all Zones of distance protection except Zone-1 with an

unblocking time delay of 2 sec.


The PSB setting are now inline with Ramakrishna committee recommendations.

------Complied

Complied

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Equipment/ System

auditated


Constituent)


Equipment/ System

auditated


Constituent)

1 Control and

Protection

Panels/Relay Setting

For ICT-1&2 Differential and REF protection is provided in the same relay (P663). NPCIL Reply 2016:

Ramakrishna report does not call for separate relays for DIFFL and REF. REF

protection is provided as main protection to detect senstive earth faults. Since

differential and REF belongs to main protection single relay can be used for both

protections.

NPCIL Mail dated 25.01.2018:

As per the original design Differential and REF protection for ICT-1&2 are provided in

the same relay (ALSTOM-P633). The issue is being taken up with designer for further

reviews.

NPCIL Reply during Special Meeting at Kaiga dated 22.06.2018:

Agreed to put separate relays as per reliabililty requirements. Separate relays for ICT-

1&2 Differential and REF protection will be provided by December 2018.


Engineering modification details are issued. Relay procurment action is in process.

Procurment process is delayed due to properitory/brand related issues.

ECD: October-19.

Pending

2 Over current protection(67 forward) has been kept enabled on all 220 kV feeders. NPCIL Reply 2016:

Earlier Main-II distance protection was not provided. Hence this protection was kept as

a back up.Now this protection will be deleted from trip as Main-II is available.


All high set elements in Dir overcurrent is removed. IDMT O/C (67 F) is only enabled

as these lines are single ACSR moose with a maximumcurrent rating of 603 amps at

75 deg C. The setting is 800 amps with TMS0.25 onIEC-SI curve.

Complied

3 LBB time setting for lines is 0.25 sec and for ICTs - 0.2 sec. NPCIL Reply 2016:

It is being reviewed by NPCIL


It has been reviewed and decided to keep settings as 200 msec for all. Will be

completed after receiving approval letter from HQ.


Received approval letter from HQ. LBB time setting for ICTs and lines will be set to

200ms after availing shutdown.


LBB settings were changed to 200 msec for both 220 KV lines. Action completed.

Complied

4 Two sources of 48 V DC are available for PLCC communication. One common output bus is

extended to the PLCC panel.

NPCIL Reply 2016:

PLCC panels are supplied, installed and maintainind by the owner of the 220 KV

line(KPTCL).


Two separate PLCC channels are available foraigaKadra and kaiga Kodasalli lines. They

have two independent 48 V DC power supplies which is having automatic back up at

the source side.

Complied

NPCIL

1) 220 kV Kaiga GS [4-6 April, 2016]

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Equipment/ System

auditated


Constituent)

5 Communication

system

No separate speech channel is provided. But used through PLCC MDX-50 Exchange for

communication.

NPCIL Reply 2016:


line(KPTCL).



line(KPTCL). Hence the issue may be taken up with KPTCL.


To be taken up with KPTCL

Pending

6 Main- 1 and Main-2 Relays are not time-synchronized with GPS but Standalone Disturbance

and Event logger are time synchronized with Station Clock which is time synchronized with

GPS.

NPCIL Reply 2016:

In KGS numerical relays are not being used for event analysis. Stand alone DR and

event logger are GPS synchronised and used for preparing trip reports. Thus

unavailability of GPS synchronisation of numerical relay does not affect the trip

analysis.


Presently Stand aalone Disturbance recorder and event logger, which are synchronised

with GPS, are used for event analysis. GPS is being procured for synchronising

MainI&II relays by June, 2018.


GPS will be procured for time synchronising of MainI&II relays by December, 2018.


New GPS system is procured and installed. Time syncronisation is done for

neumarical relays on dated 26.12.2018.

Complied


Constituent)







1) 400/230 kV Kudankulam NPP [10-11 December, 2018]

Actual Fault MVA level for 3-ph & 1-ph faults at 400 kV level of the station, calculated at periodic intervals, may be maintained with the station. The

present values of the same may be provided.

Station Earth-mat resistance measured at various earth pits in 400 kV & 230 kV switchyards (400 kV --> 0.03 ohms; 230 kV --> 0.03 ohms) are

within the mandated limits (0.5 ohms). In this regard, it is also recommended to carry out measurement of earth-resistances of all earth pits on

yearly basis, and keep updated records with the station along with suitable earth-mat lay-out diagrams.

Distance Protection Zonal reactance reaches resistive reaches & time Settings for all 400 kV feeders may be revised so as to bring them in line with

Ramakrishna Committee recommendations:

Zone-2: Reactance reach --> 150% of Protected Line in case of D/C lines. (In case of encorachment into next voltage level, necessary

discrimination may be obtained by proper time-coordination)

Time Setting --> 0.35 - 0.5 sec


Zone-4 (reverse): Reactance reach --> 50% of the Shortest Line connected at local bus

Time setting --> 1 - 1.5 sec

The above philosophy is to be followed for both Main-I & Main-II relays

It is noted that Auto-Reclosure (A/R) has not been provided for Tie-CB's of 400 kV switchyard, which may be provided along with prioity scheme. It is

also suggested to revise A/R reclaim to 25 sec from the present 180 sec.





kept as 0.5 sec.

89/95

Annexure-VI

Page 89 of 95


Equipment/ System

auditated


Constituent)















Steps may be taken to provide automatic downloading of fault records (DR's) from various protection relays to central PC.

It is observed that DEF (67N) has not been enabled for 230 kV feeders, even though the corresponding distance relays support it. It is recommended

to enable the same.

It is noted that REF protection has not been provided for 400/ 230 kV ICTs and 400 kV Bus Reactors. Steps may be taken to provide the same.

DC earth leakage is observed in both 220 V DC sources. Steps shall be taken to rectify the same on priority basis.

Two Sets of DC Batttery & Battery Chargers (48 V DC) may be provided for 230 kV PLCC system

Wiring segregation to be provided for 48 V DC system for 230 kV PLCC system

It is noted that AC Auxiliary supply required for the switchyard is being derived from Common Station Auxiliary Transformers backed up by two

Reserve Auxiliary Transformers, and no standby supply from DG set has been provided. It is recommended to fulfill this requirement by appropriate

means (either by using the Station DG or by providing for another DG set of suitable capacity) so that uninterrupted supply is ensured to all

emergency loads of the Siwtchyard.

It is observed that Time sysnchronization with GPS has not been provided to any of the line Protection Relays (400 kV as well as 230 kV). Steps may

be taken to provide the same.

It shall be ensured that DEF protection for 400 kV & 230 kV lines remains in blocked condition as long as Distance Protection is active, and becomes

active only when distance protection does not pickup.

Under VT fuse fail condition, distance protection shall normally be kept blocked. However, upon detection of a fault (sensed by negative sequence

component), it may be ensured that blocking of distance protection gives rise to operation of its inherent Over-Current protection set with a suitable

definite time delay of say 1.2 sec

Directional O/C Protection (high-set & IDMT) and Directional E/F protection (high-set & IDMT) may be reviewed on both sides of 400/ 230 kV ICT's

OF protection is to be enabled/ provided on HV side of 400/ 230 kV ICT's. It's settings employed on LV side are to be corrected.

90/95

Annexure-VI

Page 90 of 95


Equipment/ System

auditated


Constituent)









Fire Extinguishers are not found in 400 kV GIS Building, which may be provided based on standard requirements.

It is noted that BBP relay has not been tested since commissioning (in 11.03.2008). Testing of the same including other relays to be ensured at

regular intervals (4 years).

The existing Power Swing Philosophy (with all Zones blocked for unblocked time delay) to be reviewed for both 400 kV & 230 kV lines (in both Main-I

& Main-II) to adopt either of the following two approaches:

(i) Zone-1 --> Trip; Highers Zones --> Block for a delay of unblocking time delay (2 sec) & then Trip


Panels Names to be properly kept/ updated in Relay Panels Room

Wherever required, LBB Trip with Retrip timings to be revised appropriately to 200 msec and 100 msec respectively.

TTPS Lines CVT's to be tested for healthiness, and approapriate action to be taken based on test reslts including replacement of the same.

In all 400 kV & 230 kV lines, REL 521 and P442 have been employed as M-I & M-II relays respectively. In these, features such as load impedance

encroachment, over voltage protection both stages with requireddrop-off to pick-up ratio are not available. Further, the relays are of very old make,

and support from their OEM's is not forthcoming. Acoordingly, NPCIL (KKNPP) may consider replacing one or both the types of Main relays with

suitable relays.

It is recommended to carry out measurement of earth-resistances of all earth pits on yearly basis, and keep updated records with the substation

along with suitable earth-mat lay-out diagrams. It is also recommended to provide labeling for earth pit for proper identification.

91/95

Annexure-VI

Page 91 of 95


Equipment/ System

auditated


Constituent)


Equipment/ System

auditated


Constituent)

1 Bus Reactor-2 400KV Equipment Oil Leakage was observed in 400KV system Bus Reactor-2 neutral side bottom valve. NLCIL Mail dated 18.01.2018:

Oil leakage attended.

Complied

2 ICT-1&2 - Equipment Oil seepage was observed in the ICT-1 & 2. Also water leakage was found near ICT-1 NLCIL Mail dated 18.01.2018:

Oil seepage and water leakage attended.

Complied

3 Tie-1 (230 kV), Tie-

2 (230 kV), STCMS

(230 kV), Tie-3

(400 kV) & Tie-4

(400 kV)

400KV &

230KV

Protection Even though there are four short lines [Tie-1 (230 kV), Tie-2 (230 kV), STCMS (230 kV), Tie-

3 (400 kV) & Tie-4 (400 kV)], line differential protection has been provided on Tie-4 only.

NLCIL Mail dated 18.01.2018:

In 230kV Tie1 & Tie2 feeders , 2 nos of new relays with main differential protection

and backup distance protection relays were commissioned. At present distance

protection is in service. Diferential protection will be commissioned shortly. The

possibility of introducing Differential relays in 400kV Tie3 feeder and 230kV STCMS

feeder has to be explored.


In 230kV Tie1 & Tie2 feeders , 2 nos of new relays with main differential protection

and backup distance protection relays were commissioned. Differential protection is in

service. The possibility of introducing Differential relays in 400kV Tie3 feeder and

230kV STCMS feeder has to be explored.

Pending

4 Nagapatnam line

bay

400KV Equipment The line CVT (Y-ph) of 400KV Nagapatnam line was not healthy, and showing higher

indication. As such, Over Voltage protection setting (stage-I) for Nagapatnam line was set at

higher value (128%)


The Y phase CVT was replaced on 20-02-2016.

Complied

5 All the line feeders 400KV &

230KV

Protection Over current protection was kept enabled on some of the 400 kV feeders (Pugalur,

Nagapattinam, Tie-4), which should be kept disabled.


Over current protections are kept disabled.

Complied


230KV

Protection DEF (Backup earth fault) protection was not provided on any of the 400 kV feeders. On some

of the 400KV & 230KV feeders, it was kept non-directional.


Backup earth fault protection (DEF) was enabled for all feeders.

Complied

7 ICT -1 & 2 400KV/2

30KV

Protection For ICT -1 & 2, REF was not provided. However, it is observed that circulating current

protection has been provided in place of REF.


Since ICT1 & 2 are single winding transformers the protection provided is sufficient.

Complied

8 Bus Reactor 400KV Protection For Bus Reactor 1&2, Over voltage protection was kept enabled. Also no REF has been

provided to any of the bus reactors.


Over voltage protection in Reactors was disabled.Restricted earth fault (REF)

protection was not envisaged in the original design.

The issue was discussed in PCSC-76 meeting held on 26.07.2018. NLCIL was

asked to take seps to provide REF protection to all Bus Reactos at their NLC

TS2 plant.


Over voltage protection in Reactors was disabled.Restricted earth fault (REF)

protection was not envisaged in the original design.

Pending

9 Bahoor Line feeder 230KV Equipment For 230 kV feeders (except Bahoor feeder), Main-1 protection only has been provided. For

Bahoor feeder, even though Main-1 & Main-2 relays were provided, it is observed that both

relays are of same make & model.


A proposal has been taken up for providing Main 2 distance protection in 230kV

feeders. The equipments of Bahoor feeder are assets of PGCIL. Any decision for

replacement in Bahoor feeder is in PGCIL scope.


Indenting of relays have started for procurement of Main2 distance protection relays in

230kV feeders.

Pending

NLCIL

1) 400 kV NLC TS-II [8–10 February, 2016]

92/95

Annexure-VI

Page 92 of 95


Equipment/ System

auditated


Constituent)

10 All the line feeders 230KV Protection For 230 kV feeders, Power swing was blocked for all Zones and the unblocking time was kept

at 80 msec.


Power swing block was provided from Z2 to Z5 zones and the unblocking time has

been kept at 2.0 sec as per guidelines.

Complied

11 All the line feeders

except Bahoor

230KV Protection A/R was not provided on 230 kV feeders except Bahoor & Villianur feeders. On Bahoor

feeder, A/R, though commissioned, not put into service. On Villianur, A/R is in service.


The Auto reclose implementation in the remaining 230kV feeders will be taken up

shortly.


Work order has been issued to the OEM for implementing Auto reclose.

Pending

12 Bus Bar Protection All 230KV feeder relays (Main-1), were provided with only one DC source. It is observed that

the second DC supply was available in relay panel. However, no changeover arrangement for

DC supply has been provided.


The Control and relay panels are more than 30 years old .As the space available in the

230kV panels is very limited to accommodate DC changeover scheme ,the possibility of

providing DC change over scheme will be explored.


The Control and relay panels are more than 30 years old .As the space available in the

230kV panels is very limited to accommodate DC changeover scheme ,the possibility of

providing DC change over scheme will be explored.

Pending

13 Bus Bar Protection 400KV & 220KV Busbar protection was provided with only one DC source. It is observed that

the second DC supply was available in relay panel. However, no changeover arrangement for

DC supply has been provided.


It has been proposed to replace the existing bus bar protection with low impedance

busbar protection The necessary Dc changeover scheme will be introduced during the

replacement time.


It has been proposed to replace the existing bus bar protection with low impedance

busbar protection The necessary Dc changeover scheme will be introduced during the

replacement time.

Pending


230KV

Protection For all line feeders, the resistive reaches of all zones need modification. NLC informed that

the Consultant recommended settings were based on the CVT ratio of 230 kV/ 110 V and 400

kV/ 110 V. However, as the existing CVT ratios are 230 kV/ 115 V and 400 kV/ 115 V, the

final settings based on the existing ratios of CVT's would be implemented as and when

Consultant provides the same to them.


Resitive reach for all the zones were modified as per the consultant recommendations.

Complied

15 All the line feeders 230KV Protection In all 230KV line feeders SOTF function were kept disabled. NLCIL Mail dated 18.01.2018:

SOTF function is kept enabled.

Complied

16 MF-1,2,3&4 230KV Protection Eventhough MF-1,2,3&4 are short lines, PUT scheme has been implemented. NLCIL Mail dated 18.01.2018:

The feeders are radial. System is normal with PUT (Permissive Under reach Transfer

trip)

Complied

17 Pondy Line Bay 400KV Protection It is observed that in distance protection 5 zones are enabled. Zone-3 and Zone-4 settings

were kept identically.


Zone 3 & Zone 4 settings are always kept identically.


asked to revise Zone-3 & Zone-4 seetings so as to bring them in line with

Ramakrishna Committee guidelines.


P 437 relays were replaced by P443 relays. Now Zone3 setting is 1.0 sec and Zone 4

setting is 0.5 Sec.

Complied

18 General 415V ACDB It is observed that manual Changeover arrangement only has been provided between

Incomer -1 & Incomer-2 feeder in ACDB and DCDB.


Since ACDB and DCDB does not add any criticality to the system manual change over

is sufficient to take care of the situation needs.


asked to take teps to provide auto-supply changeover between Incomer-1 &

Incomer-2.


Since ACDB and DCDB does not add any criticality to the system manual change over

is sufficient to take care of the situation needs.

Pending

93/95

Annexure-VI

Page 93 of 95


Equipment/ System

auditated


Constituent)

19 General 415V DG set No dedicated DG set for switchyard auxiliaries. Generation plant emergency DG set power is

utlised for switchyard emergency lighting only.


Emergency supply is taken from the emergency bus of the main plant.

Complied

20 General - Equipment Cables laying in ACDB & DCDB room is observed to be overloaded in cable trays and some of

the cables laid haphazardly (not properly laid in Cable trays)


Cables re-arrangement is in progress.

Pending

94/95

Annexure-VI

Page 94 of 95


Equipment/ System

auditated


Constituent)

21 General - Equipment In ACDB & DCDB and Battery Charger panel, no Indication Lamps were provided. NLCIL Mail dated 18.01.2018:

Indication lamps provided.

Complied

22 General - DC system It is observed that no earthing has been provided in 220V & 48V DC Battery room for

measurement purpose. Exhaust fans are not provided in one of the 48V Battery room


Attended

Complied

23 General - DC system Earth fault was observed in DC source-2. The voltage measured values are : +ve to -ve =

238.3V; +ve to earth = 65.3V; -ve to earth = 172.6V


Earth fault in the system was cleared.

Complied

24 General - Protection Pole discrepancy (PD) for all the line & tie feeder breakers are not kept uniform. For all 400

kV feeders except tie-feeders kept as 2.4sec; For 400 kV Tie-feeders, 230 kV feeders, ICT &

Reactor breaker, it was kept at 0.1 second.


For the breakers of all feeders which are provided with auto reclose facility the Pole

descrepancy is kept at 2.4 sec. For all other breakers , pole descrepancy is kept at

100msec.

Complied

25 General - Equipment Most of the circuit breaker cubicles in 400KV & 220KV feeders have not been provided with

panel lamp. Door switches were also not working properly.


Provided.

Complied

26 General - Equipment Star ground connection for 400KV extension feeders (viz., Tie-3, Tie-4, Pugalur) and Bus

Reactor-1 & 2's CT/CVT are done in protection panel in control room. All other 400KV &

220KV feeders CT/ CVT star ground connection provided in field (switchyard).


The existing arrangemnt works properly and needs no changes.


asked to provide earthing for all mentioned equiment & feeders either in

switchyard or in control room panels.

Pending

27 General - Equipment It is observed that single earthing has been provided for few marshalling boxes in

switchyard. Also Door earthing was not provided for the marshalling boxes. NLC confirmed

that marshalling box replacement works are under progress.


A total of 62 nos of marshalling kiosks have been replaced so far with double earthing

and door earthing. Replacement of balance marshalling kiosks will be taken up shortly.


Replacement of balance marshalling kiosks are in progress.

Pending

28 General - Equipment Rusting was observed in most of the 400KV & some of the 220KV CT/CVT Marshalling Boxes.

Some of the CT/CVT Marshalling Boxes have not been body earthed. The dummy gland holes

in marshalling boxes were not covered. NLC confirmed that marshalling box replacement

works are under progress.


A total of 62 nos of marshalling kiosks have been replaced so far. Replacement of

balance marshalling kiosks will be taken up shortly.


CVT Marshalling boxes were replaced with proper earthing.

Complied

29 General - Equipment CB open/close Indication Lamps were not provided in 400KV system feeder local Circuit

breaker panels.


Existing 400kV breakers which are very old are being replaced in phased manner. Six

nos of breakers have already been replaced with proper indication lamps at local.


Proposal to replace balance breakers under progress.

Pending

30 General 400KV &

230KV

Protection No MICOM relay is time synchronised with GPS system. New set of relays with GPS synchronisation is being purchased to replace the old

version MICOM P437 relays.


All existing Micom relays replaced with P443 relays and GPS synchronized.

Complied

31 General - Equipment It was observed that standalone Event Recorder with automatic downloading facility to

centralized PC not provided.


Numerical relays provided have built in event records &DR.

Complied

32 General - Equipment It was observed that most of unused cutouts in Relay panels (both 400 kV & 230 kV) in

control room were not covered.


All unused cutouts were covered.

Complied

95/95

Annexure-VI

Page 95 of 95

Latitude

Longitude

Contact

Signature

Date

Busbar arrangement

GPS coordinate

Substation voltage level(kV)

Owner Name

Visiting Substation details

Substation Incharge Name

Substation details

State

Name

Address

I/D or O/D type

Visiting Engineer name

Visiting dateFrom

To

Annxure-VII

Page 1 of 13

Unit-1 Unit-2 Unit-3 Unit-4 Unit-5 Unit-6

1 MW Rating

2 MVA Rating

3 Rated Power Factor

4 kV Rating

5 Armature Resistance (Ra)

6 Direct Axis Synchronous Reactance (Xd)

7 Direct Axis Transient Reactance (Xd')

8 Direct Axis Sub Transient Reactance (Xd”))

9 Quadrature Axis Synchronous Reactance (Xq)

10 Quadrature Axis Transient Reactance (Xq')

11 Quadrature Axis Sub Transient Reactance (Xq”)

12 Negative Sequence Reactance (Xn)

13 Zero Sequence Reactance (Xo)

14 Potier Reactance (Xp)

15 Direct Axis Transient Open Circuit Time Constant (T’do)

16 Direct Axis Sub – Transient Open Circuit Time Constant (T”do)

17 Quadrature Axis Transient Open Circuit Time Constant (T’qo)

18 Quadrature Axis Sub – Transient Open Circuit Time Constant (T”qo)

19 Generator Inertia Constant (H)

20 NGT Voltage rating

21 NGR in ohms

22 Continuous I2 current in %

23 Max. (I22 * t) [I2 in p.u. & t in sec]

**Provide AVR and Governor data seperately

I2 = Negative sequence current of generator

24AVR model (block diagram, time constant values, gain values, output graphs of AVR)

25Governor model (block diagram, time constant values, gain values, output graphs of

governor)

26PSS model (block diagram, time constant values, gain values, output graphs of PSS)

Sl. No. ParticularsValues (Specify the units of the values) either ohms or p.u.

Generator details

Annxure-VII

Page 2 of 13

Particulars

Name of the transformer ICT1 ICT2

1 MVA Rating 100 100

2 HV (kV) 220 220

3 IV (kV) 132 132

4 LV (kV) 33 33

5 % impedance At Max Tap 7.49 7.49

6 % impedance At Normal Tap 7.41 7.41

7 % impedance At Minimum Tap 7.56 7.56

8 Tap Maximum Number 17 17

9 Tap Minimum Number 1 1

10 Nominal Tap 9 9

11 Minimum Voltage (kV) 187 187

12 Maximum Voltage (kV) 231 231

13 Winding Configuration YNaOd11 YNaOd11

14 Average loading of the transformer in MW

15 Peak loading of the transformer in MW

16 From Breaker Rating (kA)

17 To Breaker Rating (kA)

18 Loading (MVAR)

19 Loading (MW)

Transformer Details

Sl. No.Interconnecting Transformer

Annxure-VII

Page 3 of 13

65 deg C 75 deg C

Bay No. From Substation To Substation Voltage level (kV) No. of Ckts Length (km) Conductor TypeAverage loading of

the line in MW

Peak loading of the

line in MWR (ohm/km) X (ohm/km) B/2 (mho/km) R (ohm/km) X (ohm/km) B/2 (mho/km)

Available (Yes/

No)

Type (3-ph/ 1-

ph)

Implemented

from (BCU/ M-I/

M-II/ M-I & M-II)

Dead-Time Reclaim-Time

Thermal rating based on allowable

conductor temperature at ambient

temperature

Line Details Positive sequence impedance Zero sequence impedance Auto-Reclosure Details

Annxure-VII

Page 4 of 13

Bay NoRemarks if any Sl No. voltage rating in kV MVAr rating

Neutral Grounding

Reactor (if available)

sample data= 1 Nelamangala Hassan 400 kV 50

Connected line

Line reactor detailsBus Reactor data

Sl No. Connecting S/S busVoltage rating

(kV)MVAr rating

Annxure-VII

Page 5 of 13

From S/S To S/S

Shunt Capacitor data

SL NO. Connecting S/S busVoltage rating

(kV)MVAr rating Switching or Fixed

Series Capacitor

Sl NoConnecting line Voltage rating

(kV)MVAr rating Switching or Fixed

Annxure-VII

Page 6 of 13

Remarks

Location of CT

Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5

KPV (in V) knee point voltage Iexc at Vk/4 (in mA) magnetising current

201

Primary

current (A)

Secondary

current (A)

No of

Cores

Output (VA) Accuracy class RCT at 75deg centi in ohmBay No CT Name Make Serial no. Type Ratio

ISF/ALF

Nelamangala-

dabaspet line

HEPTACARE POWER

INDUSTRIES (P) LTD.MN-701 O.D,O.C,D.T 1200-600-300/1-1-1-1 600 1 5

202 TRANSFORMER-4 BHEL 2446802 200-400-800/1-1-1 800 1 4

On the outgoing

Nelamangala -

Dabaspet line

Transformer HV 30 — 0.2 5P10 PS PS — — —40 — — — — —

CT Details

30 — 0.2S 5P PS PS PS < 5 —40 — — 10 — — > 200 < 30 < 30> 200— — > 200 — — < 30— — < 12

— —

3

3

6

3

3

6

— —

< 12 < 12

30

30

15

30

30

15

——

600

600

1200

600

600

1200

— — —

Annxure-VII

Page 7 of 13

A-N

VOLTS VOLTS BURDEN (VA)ACCURACY

CLASSVOLTS BURDEN (VA)

ACCURACY

CLASSVOLTS BURDEN (VA)

ACCURACY

CLASS

PT Details

220

220

SECONDARY WINDINGHIGHEST

SYSTEM

VOLTAGE

(in kV)

VOLTAGE FACTORWINDING-I WINDING-II WINDING-III

1a-1n 2a-2n 3a-3n

Primary

Voltage

level

connected

in kV

PT NameManufacturer

NameYEAR

PRIMARY WINDING

TRANSFORMER-3 SCT LTD. 2012 220000/√3 110/√3 110/√3

bay NO

200 3P 245 1.2 CONT./1.5-30 SEC50 0.2 110/√3 200 3P

400 1 110/3 100 3BUSCOUPLER BALTEAU 2012 220000/√3 110/√3

Annxure-VII

Page 8 of 13

Bay No. Maker Yearlocation of

CVT

Total burden

simultaneously(

VA)

Thermal

burden

Rated

voltage

Highest

system

voltage

Voltage factorHF

Capacitance

Primary

Capacitance

C1

Secondary

Capacitance

C2

Connection RatioBurden

Accuracy Class

1.2 CONT./1.5-30 SEC 4400 4881 47186500 220000/√3 245208 AREVA 2006 200

CVT Details

1a-1n 2a-

2n

220000/√3/(110/√3/

110/√3)

100/5P

100/3P

Annxure-VII

Page 9 of 13

PSM TSM

Substation Relay data

Panel no. Panel name ElementConnected

CT ratioProtection(Main/Backup) Protective Relay Manufacture's name

201 Dabaspet Transmission line 600/1 MAIN

Relay type Model no.

COLLECTEDDISTANCE ASEA NUMERICAL P442

Numerical Others RemarksModel Description Version no.Electromechanical

Static

COLLECTEDBACKUP O/C & E/F AREVA NUMERICAL P127

Image No.

Annxure-VII

Page 10 of 13

PSM TSM

Generating Station Relay data

Panel no. Panel name ElementConnected CT

ratioProtection Protective Relay Manufacture's name Image no.Numerical Others RemarksModel Description Version no.

ElectromechanicalStaticRelay type Model no.

Annxure-VII

Page 11 of 13

Closing (VDC) Trippin (VDC) Spring Charge (VAC)

2013 220 220 4152400 3150 50 40 KA/3 IEC 62271-100

245 40 100 2006

Nelamangala SF6 CROMPTON

GREAVES202 41421C 200-SFM-40B 245 40 100

3000 3150 50 40 KA/3 IEC 62271-100Nelamangala SF6 AREVA 201 150420 GL314

CB Details

Breaking Current (kA) Making Current (kA Peak) Weight (Kgs) Rated Current (A)Feeder Number Switch board Name Serial Number Type Rated voltage (KV)Number Tag Number Sub Station Medium Make Rated Frequency (Hz) STC (kA/1sec) Standard Year Auxilary Volts

Annxure-VII

Page 12 of 13

Bay No. From bus To bus Voltage level (kV) Breaker Rating (kA)

Bus Coupler

Annxure-VII

Page 13 of 13

Latitude

Longitude

Data collection periodFrom

To

Contact

Signature

Date

Busbar arrangement

GPS coordinate

Substation voltage levels(kV)

Owner Name

Substation Incharge details


Substation details

State

Name of the substation/generating

station/pooling substation

Address

I/D or O/D type

Annexure-VIII

Page 1 of 7

1Indicate the feeder numbers coming from wind farm connecting to the pooling substation. It is given clearly in the 'Wind_Gen_Details' sheet, point No. 9. (If

feeder numbers are not there, assume the feeder numbers and send)

2Indicate number of turbines in each feeder as per the sample data entry in point No. 10 (of Wing_Gen_Details)

3

Generator parameters for the wind generators will be available in the generator data sheet. If not available, then they will be available at corporate office.

Annexure-VIII

Page 2 of 7

Sl. No.Parameters for Type 1, Type 2 and Type 3 wind

turbines

Type of turbine- Squirrell cage

Induction generator (SCIG)

Type 1

Wound rotor induction

generator (WRIG)

Type2

Doubly Fed Induction

Generator(DFIG)

Type 3

Sl. No. Parameters for Type 4 wind turbine

Permanent Magnet Synchronous

Generator (PMSG)

Type 4

1 MW rating of each turbine 1.25 1.5 1 MW rating of each turbine

2 MVA rating of each turbine 1.41 1.6 2 MVA rating of each turbine

3 No. of poles in generator 4 4 3 No. of poles in generator

4 Gear Box ratio 95 96 4 Gear Box ratio

5 Turbine rated RPM 16 15.5 5 Turbine rated RPM

6 Turbine diameter in M 42 43 6 Turbine diameter in M

7 Cut in wind speed in m/s 3 3.5 7 Cut in wind speed in m/s

8 Cut out wind speed in m/s 20 25 8 Cut out wind speed in m/s

9 Wind farm feeder numbers 1, 2 1, 3 , 4 9 Feeder numbers

10 No. of turbines in each feeder 20, 10 10, 15, 25 10 No. of turbines in each feeder

11 Stator winding connection star grounded star grounded 11 Stator winding connection

12 Rated power factor 0.9 0.9 12 Rated power factor

Generator parameters Machine parameters

13 Generator rated voltage in kV 0.69 0.69 13 Convertor rating in MVA

14 Stator reactance in pu on its own MVA rating 0.09743 0.0955 14 Generator rated voltage in kV

15 Stator resistance in pu on its own MVA rating 0.0063125 0.0062 15Armature Resistance (Ra) in pu on its own MVA

rating

16 Rotor reactance in pu on its own MVA rating 0.04462 0.1046 16Direct Axis Synchronous Reactance (Xd) pu on its

own MVA rating

17 Rotor resistance in pu on its own MVA rating 0.015319 0.0078 17Direct Axis Transient Reactance (Xd') pu on its own

MVA rating

18 Magnetising reactance in pu on its own MVA rating 3.13 4.2453 18Direct Axis Sub Transient Reactance (Xd”)) pu on its

own MVA rating

19 Efficiency in % 96 96 19Quadrature Axis Synchronous Reactance (Xq) pu on

its own MVA rating

20 Rated slip in % 0.4 0.73 20Quadrature Axis Transient Reactance (Xq') pu on its

own MVA rating

21 Inertia in S or MJ/MVA 1.5 1.7 21Quadrature Axis Sub Transient Reactance (Xq”) pu

on its own MVA rating

22Negative Sequence Reactance (Xn) pu on its own

MVA rating

23Zero Sequence Reactance (Xo) pu on its own MVA

rating

24 Inertia in S or MJ/MVA

Particulars

Annexure-VIII

Page 3 of 7

Annexure-VIII

Page 4 of 7

Pooling substation transformer details

Particulars

Name of the substation Ponnapuram 110kV Marudur 110kV Poolavadi 110kV

Name of the transformer TR1

1 MVA Rating 40

2 HV (kV) 110

4 LV (kV) 33

5 % impedance At Max Tap 7.49%

6 % impedance At Nominal Tap 7.41%

7 % impedance At Minimum Tap 7.56%

8 Tap Maximum Number 9

9 Tap Minimum Number 1

10 Nominal Tap 5

11 Minimum Voltage (kV) 104.5

12 Maximum Voltage (kV) 115.5

13 Winding Configuration YnD11

14 From Breaker Rating (kA) 40

15 To Breaker Rating (kA) 40

Sl. No.

Transformer Details

Annexure-VIII

Page 5 of 7

Details of those lines to be given which are connecting from wind farm Pooling Station to near by 220 or 230 or 400 kV substation

Sl. No

Wind

farm

Owner

name

Wind farm

capacity

in MW

From Substation

&voltage level

To Substation &

voltage level

Voltage level

of line in (kV)No. of Ckts Length (km)

Conductor

TypeCT Ratio No. of cores Connected CT ratio Core No. Core 1 Core 2 Core 3 Core 4 Core 5 Core 1 Core 2 Core 3 Core 4 Core 5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5

Available

(Yes/ No)

Type (3-ph/

1-ph)

Implemented

from (BCU/ M-I/

M-II/ M-I & M-II)

Dead-TimeReclaim-

Time

4 Marudur 110kV Ponnapuram 230kV 110 1 9.4 Panther80.53

1200/1

3 Poolavadi 110kV Marudur 110kV 110 1 8.8 Panther

100

82.5

Panther

2 Thungavai 110kV Myvadi 230kV 110 1 16.5 Panther

1 Thungavai 110kV Ponnapuram 230kV 110 1 7 1200-600-300/1-1-1 3

If electromechanical or static

relays,please enter the settings

manually or send the settings in

soft copy

Auto-Reclosure DetailsLine DetailsProtection

(Main/Backup)Protective Relay

Manufacture's

nameRelay type Model no. Model Description

Static/

Numerical/

Electromechanical

If numerical relay,

download the setting files

in .csv or .xml or .txt files

RCT at 75deg centi in ohm KPV (in V) knee point voltage Iexc at Vk/4 (in mA) magnetising currentCT details of the line

Output VA burden Accuracy class

Annexure-VIII

Page 6 of 7

If there are capacitors connected at wind farm pooling station then add the data here:

Shunt Capacitor data

SL NO. Connecting S/S busVoltage rating

(kV)MVAr rating Switched or Fixed

Annexure-VIII

Page 7 of 7

Latitude

Longitude

Data collection periodFrom

To

Contact

Signature

Date

Busbar arrangement

GPS coordinate

Substation voltage levels(kV)

Owner Name

Substation Incharge details


Substation details

State

Name of the substation/generating

station/pooling substation

Address

I/D or O/D type

Annexure-IX

Page 1 of 7

1 Fill the data for solar plant w.r.t each feeder.

2 If the data for multiple feeders are similar then you can fill data for only 1 feeder and intimate the capacity for other feeders

3 Parameters for PV Panel, Inverter data will be available in their respective data sheets. If not available, then the will be available at corporate

office.

Annexure-IX

Page 2 of 7

Data requirement for solar power grid impact study

1

Values Values

feeder 1 feeder 2

1

2

2

Sl.no

1

4

5

6

7

8

9

10

11

12

Particulars

Power factor control mode

Voltage control mode

Type of technology ( like Polycrystalline/Monocrystalline/Thin film)

Rated power of each module/panel (watts)

Open circuit

Efficiency of the module/panel (%)

Open circuit voltage-Voc (volts)

Short circuit current-Isc (amps)

Maximum power point voltage-Vpm (volts)

13

Noct condition ( if condition is power

generation, then provide the value

else tick mark if it is open circuit)

Maximum power point current-Ipm (amps)

Temperature co-efficient rated power (%/ 0C )

Temperature co-efficient of voltage (V/ 0C)

Nominal operating cell temperature-Noct ( 0C)

Mention whether operating mode of the plant is power factor control mode or it is voltage control

mode. Specify the range of power factor or voltage in the Table 1

Table 2: Solar PV panel details

Substation name along with voltage level

Table 1: Operating mode of the plant

Operating mode

Solar PV panel details covering type, Manufacturer, Model, number of modules, strings, arrays, power

rating, etc. Provide the data sheet covering the parameters requested in Table 2.

Annexure-IX

Page 3 of 7

14

15

3

Sl.no

1

2

3

4

5

6

7

9

10

11

12

13

14

15

3 phase to ground fault (kA)

Single line to ground fault (kA)

17

4

Inverter details covering voltage range, reactive power capability, efficiency, harmonics etc. Provide

the data sheet covering the parameters requested in Table 3.

Table 3: Required inverter details

8 Efficiency of the inverter in %

Max efficiency

European efficiency

CEC efficiency

Capacity of each inverter (kVA)

Number of MPPT’s in each inverter

Voltage range of MPPT’s (volts)

Maximum operating power factor range

Particulars

Total number of inverters

Power generation (watts)

Number of modules/panels connected in a string

Number of strings in an array

Reactive power capability in inductive side (kVAr)

Reactive power capability in capacitive side (kVAr)

Maximum DC power (watts)

16Maximum short circuit current contribution from

inverter for

LVRT characteristics of inverter.

Mention the IEC certifications obtained for the inverter.

Voltage rating of DC input side (volts)

Voltage rating of AC output side (volts)

Frequency on AC side (Hz)

Maximum total harmonic distortion (%)

AC operating voltage range (volts)

Operating frequency range (Hz)

13

Noct condition ( if condition is power

generation, then provide the value

else tick mark if it is open circuit)

Annexure-IX

Page 4 of 7

5

Sl.no

1 hourly data for one year period

2 hourly data for one year period

Array tilt angle

(deg)

Array azimuth

angle (deg)

Reference for

module azimuth

angle

(south/north)

One axis trackingModule tilt angle

(deg)

Two axis tracking -

4

3

Mounting type (provide the values if applicable and

tick mark if it is two axis tracking )

fixed

1

Global horizontal irradiance-GHI (w/m2)

Diffused horizontal irradiance-DHI (w/m2)

OR

Direct normal irradiance-DNI (w/m2)

Standard meridian (deg,min)

Ambient temperature ( 0C)

Table 5: Required solar irradiance data

OR

Particulars

Solar irradiance on tilted plane (w/m2 )

Solar irradiance data. Either hourly data of solar irradiance in w/m2 for one year period or GHI, DHI or

DNI values as per Table 5.

Annexure-IX

Page 5 of 7

Pooling substation transformer details

Particulars

Name of the substation Ponnapuram 110kV Marudur 110kV Poolavadi 110kV

Name of the transformer TR1

1 MVA Rating 40

2 HV (kV) 110

4 LV (kV) 33

5 % impedance At Max Tap 7.49%

6 % impedance At Nominal Tap 7.41%

7 % impedance At Minimum Tap 7.56%

8 Tap Maximum Number 9

9 Tap Minimum Number 1

10 Nominal Tap 5

11 Minimum Voltage (kV) 104.5

12 Maximum Voltage (kV) 115.5

13 Winding Configuration YnD11

14 From Breaker Rating (kA) 40

15 To Breaker Rating (kA) 40

Sl. No.

Transformer Details

Annexure-IX

Page 6 of 7

Line details of those lines to be given which are connecting from Solar Pooling Station to to near by 220 kV or 230 kV or 400 kV Substation

Sl. No

Solar

farm

Owner

name

Solar

farm

capacit

y in MW

From Substation

&voltage level

To Substation &

voltage level

Voltage level

of line in (kV)No. of Ckts Length (km)

Conductor

TypeCT Ratio No. of cores Connected CT ratio Core No. Core 1 Core 2 Core 3 Core 4

Core

5Core 1 Core 2 Core 3 Core 4 Core 5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5 Core-1 Core-2 Core-3 Core-4 Core-5

Available

(Yes/ No)

Type (3-ph/

1-ph)

Implemented

from (BCU/ M-I/

M-II/ M-I & M-II)

Dead-TimeReclaim-

Time

Line Details

Protection

(Main/Backup)Protective Relay

Manufacture's

nameRelay type Model no. Model Description

Static/

Numerical/

Electromechanical

If numerical relay,

download the setting files

in .csv or .xml or .txt files

If electromechanical or static

relays,please enter the settings

manually or send the settings in soft

copy

Auto-Reclosure Details

82.5

80.534 Marudur 110kV Ponnapuram 230kV 110 1 9.4 Panther

1200/1

3 Poolavadi 110kV Marudur 110kV 110 1 8.8 Panther

100

1200-600-300/1-1-1Panther

2 Thungavai 110kV Myvadi 230kV 110 1 16.5 Panther

1 Thungavai 110kV Ponnapuram 230kV 110 1 7 3

RCT at 75deg centi in ohm KPV (in V) knee point voltage Iexc at Vk/4 (in mA) magnetising currentCT details of the line

Output VA burden Accuracy class

Annexure-IX

Page 7 of 7

81st PCSC meeting

24th January 2019

Annexure-X

Page 1 of 28

Details of Grid Disturbances

Annexure-X

Page 2 of 28

81.I.1. Complete Outage of 230kV SiruseriSS of TANTRANSCO at 05:39hrs on 09-01-2019

• Triggering Incident: Y-phase fault in 230kV Siruseri Sholinganallur line• Bus Bar Protection operated at 230kV Siruseri• ABB make Radha static Bus bar protection• Load loss:74 MW

Annexure-X

Page 3 of 28

Observations from DR

Siruseri End Sholinganallur End

DR Trigger: 05:39:40.476 hrs

Y Phase Fault, Ifault=7.8 kA

Z1 Operated, Carrier Sent

Carrier Receive

BBP Operated

DR Trigger: 05.39.40.000 hrs

Y Phase Fault

Z1 Operated, Carrier Receive

A/r Operated

Y Phase- B Phase Fault

A/r Block

Points for Review

• Operation of BBP at 230kVSiruseri end

• Single bus operation at230kV Siruseri SS

ELDRELDR

A/r dead time =600ms

Annexure-X

Page 4 of 28

GD\16632_SENDEL-230kV_SIRUSERI_OTTIYAMPAKKAM FEEDER_EL.pdf

GD\16632_SENDDR-230kV_SIRUSERI_OTTIYAMBAKKAM_FEEDER_DR.pdf

GD\16632_RENDEL-230KV_OTTIYAMBAKKAM_SIRUSERI FEEDER _EL.pdf

GD\16632_RENDDR-230KV_OTTIYAMBAKKAM_SIRUSERI FEEDER _DR.pdf

Details of Grid Incidents

Annexure-X

Page 5 of 28

81.II.1. Tripping of 400 kV Mahboobnagar-Uravakonda line-1 on 04-12-2018 at 09:57 hrs

• Feeder tripped due to mal-operation of GOOSE signal messaging at UV

Konda end

• DT received at Mahboobnagar end

• Findings and remedial actions taken may be furnished

Mahboobnagar End Uravakonda End


DT Receive ELDR ELDR NA

Annexure-X

Page 6 of 28

GI\1\16564_SENDEL-VELTOOR_URVAKONDA_LINE_1_EL 04-12-18.pdf

GI\1\16564_SENDDR-VELTOOR_URVAKONDA_LINE_1_DR 04-12-18.pdf

GI\1\16564_RENDEL-URAVAKONDA-VELTOOR-2-EL-04.12.18.pdf

Minutes of 79th PCSC Meeting held on 25-10-2018 at SRPC

Annexure-X

Page 7 of 28

81.II.2. Tripping of HVDC Talcher-Kolar Pole-1on 12-12-2018 at 19:41 hrs

• Pole-1 tripped at Kolar end on transformer protection on operation of

Bucholz alarm in Y-phase converter transformer.

• Pole-2 metallic return mode - 880MW.

• Antecedent total -2260 MW

• SPS of HVDC Talcher-Kolar at Kolar end didn’t operate

EL

SRLDC Email reg SPS

DR

Annexure-X

Page 8 of 28

GI\2\16576_SENDEL-KLR_TLCR_POLE1_EL.pdf

GI\2\Email regarding non operation of SPS.pdf

GI\2\16576_SENDDR-KLR_TLCR_POLE1_DR.pdf

SCADA Data plots

PMU plots

Annexure-X

Page 9 of 28


Annexure-X

Page 10 of 28

Vemagiri End Satenapalli End

81.II.3. Tripping of 400 kV Vemagiri-Satenapallion 13-12-2018 at 21:48 hrs

• Over voltage stg-1 protection at Vemagiri end.

• DT received at Satenapalli end.

• DR of Vemagiri end is not submitted.

DR NA EL ELDR

Annexure-X

Page 11 of 28

GI\2\16576_SENDDR-KLR_TLCR_POLE1_DR.pdf

GI\3\16584_SENDEL-VJA-NLR2_EL-13.12.2018.pdf

GI\3\16583_RENDEL-416_Station Events_13.12.18_21.48.pdf

GI\3\16583_RENDDR-416_DR_R670_13_12_2018_21.48.pdf

81.II.4. Tripping of 400 kV KTPS-7 – Julurpaduline-1 on 16-12-2018 at 00:30 hrs

• Over voltage stg-1 protection at Julurpadu end.

• DT received at KTPS-7 end.

• less than O/v stg-1 pickup threshold considering drop off to pickup ratio

of 98%.

KTPS-7 End Julurpadu End

Vr-248kV, Vy-249kV, Vb-247kVDR EL

ELDR

Remedial Actions Furnished by TSTRANSCO:

Over Voltage settings at Julurupadu end were not revised as per SRPCrevised setting. Same was revised on 24-12-2018.

OVR Settings: 111%, 10 sec

Annexure-X

Page 12 of 28

GI\4\16581_SENDDR-DR.pdf

GI\4\16581_SENDEL-events.pdf

GI\4\16581_RENDEL-JULURUPADU_KTPSVII_LINE_1_EL 16-12-18.PDF

GI\4\16581_RENDDR-JULURUPADU_KTPSVII_LINE_1_DR 16-12-18.pdf

81.II.5. Tripping of 400kV KTPS-7 –Julurupaduline-2 on 16-12-2018 at 2:14 hrs

• Over voltage stg-1 protection at Julurpadu end.

• DT received at KTPS-7 end.

• less than O/v stg-1 pickup threshold considering drop off to pickup ratio

of 98%.

KTPS-7 End Julurpadu End


ELDR

Remedial Actions Furnished by TSTRANSCO:

Over Voltage settings at Julurupadu end were not revised as per SRPCrevised setting. Same was revised on 24-12-2018.


Annexure-X

Page 13 of 28

GI\5\16580_SENDDR-dr.pdf

GI\5\16580_SENDEL-events.pdf

GI\5\16580_RENDEL-JULURUPADU_KTPSVII_LINE_2_EL 16-12-18.PDF

GI\5\16580_RENDDR-JULURUPADU_KTPSVII_LINE_2_DR 16-12-18.pdf

81.II.6. Tripping of 400kV Suryapet-Julurupaduline-2 on 17-12-2018 at 00:15 hrs

• Over voltage stg-1 protection at Suryapet end.

• DT received at Julurpadu end.

• DR of Suryapet end is not submitted.

Suryapet End Julurpadu End

DR NA EL ELDR

SRLDC Email reg DR


Annexure-X

Page 14 of 28

GI\6\16587_SENDEL-SURYAPET_JULURUPADU_LINE_2_EL 17-12-18.pdf

GI\6\16587_RENDEL-JULURUPADU_SURYAPET_LINE_2_EL 17-12-18.PDF

GI\6\16587_RENDDR-JULURUPADU_SURYAPET_LINE_2_DR 17-12-18.pdf

GI\6\SRLDC Email.pdf

81.II.7. Tripping of 400kV Kalpakka-Asupakka line-1on 17-12-2018 at 10:32 hrs

• Over voltage stg-1 protection at Asupaka end.

• DT received at Kalpakka end.

• Voltage difference was observed between R, Y & B phases

Kalpakka End Asupaka End


ELDR


DR in cfg and dat format

Annexure-X

Page 15 of 28

GI\7\16588_SENDDR-ASUPAKA(KMM1) DT.17.12.2018.pdf

GI\7\16588_SENDEL-Operational log.pdf

GI\7\16588_RENDEL-ASUPAKA_KALPAKA_LINE_EL 17-12-18.PDF

GI\7\16588_RENDDR-ASUPAKA_KALPAKA_LINE_DR 17-12-18.pdf


Annexure-X

Page 16 of 28

81.II.8. Tripping of 400/200 kV ICT-3 at Vemagiri (AP) on 17-12-2018 at 17:46 hrs

• As per the report submitted, ICT-3 LV Breaker opened due to DC earth

fault.

• Findings and remedial actions may be furnished

Tripping of 400/200 kV ICT-3 at Vemagiri (AP) on 04-10-2018 at 11:32 hrs

Similar Tripping in the Past!

• As per FIR, ICT-3 LV CB got tripped due to suspected DC earth fault. • As a remedial measure the faulty breaker control cable replaced with armoured cable

on 04/10/18.

Annexure-X

Page 17 of 28

81.II.9. Tripping of 220kV Yerandahalli-Hosur lineon 22-12-2018 at 00:58 hrs

• Triggering incident: Y-phase fault in the line

• Line tripped only at Yerrandahalli end on Earth Fault relay operation.


Yerandahalli End Hosur End

DR Trigger: 01:00:53.768hrs

IN : 250A

IN>3 Start

Line didn’t trip at Hosur end.

EL NADR ELDR NA

Remedial Actions Furnished by KPTCL

At Yerandanahalli: In Main-I relay, In>3 element was found to be enabled with

default current setting & instantaneous time delay, the same has been rectified.

Annexure-X

Page 18 of 28

GI\9\16590_SENDDR-yhalli_h1.pdf

GI\9\16590_RENDEL-230kV_HOSUR _ YERANDAHALLY_FEEDER_EL.pdf

PMU Plots:Annexure-X

Page 19 of 28

81.II.10. Tripping of 400 kV Mamidapally-Dindi line-2on 26-12-2018 at 01:42 hrs

• Line tripped only at Mamidipally end without any relay indications.

• From PMU plots, fault was not observed.

• Line was kept charged from Mamidipally end.

• EL of Mamidipally end is not time synchronised with GPS.

• Findings and remedial actions taken shall be furnished.


Mamidapally End Dindi End


ELDR EL NADR NA

Annexure-X

Page 20 of 28

GI\10\16596_SENDEL-MAMIDIPALLY_DINDI_LINE_2_EL 26-12-18.pdf

GI\10\16596_SENDDR-MAMIDIPALLY_DINDI_LINE_2_DR 26-12-18.pdf

PMU Plots:Annexure-X

Page 21 of 28

81.II.11. Tripping of 400kV Suryapet- Julurupadu line-2 on 26-12-2018 at 02:12 hrs and 23:01 hrs

• Over Voltage stg-1 protection at Julurupadu end.

• Direct trip received at Suryapet end.

• OVR settings adopted needs review


Suryapet End Julurupadu End

26-12-2018 at 02:12 hrs

26-12-2018 at 23:01 hrs

26-12-2018 at 02:12 hrs

R-247kV Y-248kV & B-245 kV

26-12-2018 at 23:01 hrs

R-246kV Y-246kV & B-244 kV

ELDR NAEL

DR EL

DR

ELDR NA


Annexure-X

Page 22 of 28

GI\11\1\16595_SENDEL-SURYAPET_JULURUPADU_LINE_2_EL 26-12-18 02.pdf


GI\11\1\16595_RENDEL-JULURUPADU_SURYAPET_LINE_2_EL 26-12-18 02.pdf

GI\11\2\16597_RENDDR-JULURUPADU_SURYAPET_LINE_2_DR 26-12-18 23.pdf

GI\11\2\16597_RENDEL-JULURUPADU_SURYAPET_LINE_2_EL 26-12-18 23.pdf

GI\11\1\16595_RENDDR-JULURUPADU_SURYAPET_LINE_2_DR 26-12-18 02.pdf

GI\11\2\16597_SENDEL-SURYAPET_JULURUPADU_LINE_2_EL 26-12-18 23.pdf


81.II.12. Tripping of 400kV Singareni-Sundila line-2on 27-12-2018 at 17:22 hrs

• Over voltage stg-1 protection at Sundila end.

• DT received at Singareni end.

• DR of Sundila end is not submitted.

Singareni End Sundila End

DR EL EL NADR NA

SRLDC Email reg DR

Annexure-X

Page 23 of 28

GI\12\16598_SENDDR-SINGARENI_SUNDILLA_LINE_DR 27-12-18.pdf

GI\12\16598_SENDEL-SINGARENI_SUNDILLA_LINE_EL 27-12-18.pdf

GI\6\16587_RENDEL-JULURUPADU_SURYAPET_LINE_2_EL 17-12-18.PDF

GI\6\16587_RENDDR-JULURUPADU_SURYAPET_LINE_2_DR 17-12-18.pdf

GI\12\Email seeking DR.pdf

81.II.13. Tripping of 230kV Sulurpet- Gummidipoondiline on 30-12-2018 at 11:36 hrs

• Line tripped only at

Gummidipoondi end due to

loss of PT supply

• RAZOA (static) relay issued trip

• During bus changeover, bus PT

supply to relay panel was not

changed.

• There is no line CVT for 230kV

Sulurpet- Gummidipoondi line

at Gummidipoondi end

SLD

EL NADR NA

Annexure-X

Page 24 of 28

GI\13\SLD.jpg

81.II.14. Tripping of 400kV Annaikadavu- Rasipalayamline-1&2 on 31-12-2018 at 15:09 hrs and 06:02 hrs

• Lines tripped only at Annaikadavu end

• DT extended from Rasipalayam end protection coupler due to DC earth fault.

• Remedial Actions Furnished: • OEM has been referred for rectification of protection coupler issue.• DC earth leakage occurred during testing of new reactor bay @

Rasipalayam end.

DR EL

DR EL

line-1

line-2

Annexure-X

Page 25 of 28

GI\14\1\16612_SENDDR-400kV_ANAIKADAVU_ RASIPALAYAM FEEDER.2_DR.pdf

GI\14\1\16612_SENDEL-400kV_ANAIKADAVU_ RASIPALAYAM FEEDER.2_EL.pdf

GI\14\2\16613_SENDDR-400kV_ANAIKADAVU_ RASIPALAYAM FEEDER.1_DR.pdf

GI\14\2\16613_SENDEL-400kV_ANAIKADAVU_ RASIPALAYAM FEEDER.1_EL.pdf

Failure or Non-Operation of Auto Reclose during Transient Fault

Annexure-X

Page 26 of 28

Sl.

No.Element Date &

TimeReason Sending End Receiving End

1

Tripping of 220kV KTPS Nunnaline

07-12-2018at 11:32 hrs

B-phase to earth fault. Auto-reclose not enabled forline

DR/EL not available

Failure or non-operation of Auto reclose

during transient fault

DR EL

Annexure-X

Page 27 of 28

AR\1\16569_RENDDR-NUNNA-KTPS-07-12-18-DR.pdf

AR\1\New Doc 2019-01-03 14.51.50.pdf

Tripping at one end/ PLCC mal-operation

Sr.

No.Element Date &

TimeReason Sending end Receiving end

1

Tripping of

400kV

Maradam-

Kalpakka line-1

11-12-2018 at

11:55 hrs

Line tripped on direct trip receive at

Kalpakka and was in service from Maradam

2

Tripping of

400kV

Maradam-

Kalpakka line-1

11-12-2018 at

12:00 hrs

Line tripped on direct trip receive at

Kalpakka and was in service from Maradam

3

Tripping of 400

kV Warangal-

Boopalapalli

line-2

15-12-2018 at

20:42 hrs

Line tripped at Bhoopalapalli end only and

was holding from warangal s/s. FIR, DR and

EL of Bhoopalapally were not furnished.

ELNA

DR

NA NA

NA NA EL

NA NA DR EL

Annexure-X

Page 28 of 28

PLCC\1\16572_RENDEL-EL MRDM-1 DT.11-12-2018.pdf

PLCC\400kV Narnoor-Srisailam\Srisailam end_DR.pdf

PLCC\2\16573_RENDDR-M2 11-12-2018.pdf





PLCC\2\16573_RENDEL-EL MRDM2 DT.11-12-2018.pdf



PLCC\3\16589_RENDDR-DR.pdf

PLCC\3\16589_RENDEL-EL.pdf

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81) of SRPC held on 24th January, 2019

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