Agenda for the 71st Meeting of PCSC scheduled to be held on 31
st January, 2018 Page 1
SOUTHERN REGIONAL POWER COMMITTEE BENGALURU
Agenda for the 72nd Meeting of Protection Coordination Sub-Committee of SRPC to be held on 15th March, 2018
1. Introduction
2. Confirmation of Minutes of last PCSC meeting
Confirmation of minutes of 71st Protection Coordination Sub-Committee meeting held on 31.01.2018.
3. Grid Occurrences
3.1 Grid Disturbances (GD), Grid Incidences (GI), and trippings due to failure of Auto-reclosing (A/R), and mal-operation of PLCC equipment that occurred during the period January – February, 2018 given at Annexure-I would be discussed in the PCSC meeting.
Constituents are requested to furnish the following information in respect of the above grid occurrences to have fruitful discussions.
(a) Single line diagram of the station with switching devices, CT, PT and relay details. (b) Cause of the tripping & Remedial Action taken (c) Relay setting details
Constituents are requested to bring/ furnish full particulars of the tripping events pertaining to their system.
3.2 In compliance of Regulations 5.2 (r) of IEGC, the Constituents are required to furnish
the following information in respect of Grid Occurrences within 24 hrs of occurrence of the same to SRLDC/ SRPC: (a) First Information Report (FIR) (b) Event Logger (EL) output (c) Disturbance Recorder (DR) output (d) Trip event analysis report (with pre and post fault system conditions) Non-furnishing of tripping details (FIR/DR/EL/TR) for the period 01.01.2018 – 15.02.2018 had been brought to Constituents’ notice vide letters (i) No. SRPC/ SE-III/ PCSC/ 2018/ 575-80 dated 19.01.2018, (ii) No. SRPC/ SE-III/ PCSC/ 2018/ 1102 - 4 dated 08.02.2018, and (iii) N. SRPC/ SE-III/ PCSC/ 2018/ 1196 – 201 dated 21.02.2018. Non-compliance in this regard would be discussed in the meeting.
4. Submission of Reports/Compliance by Constituents
4.1 Status of implementation of pending Protection Coordination
Sub-Committee (PCSC) Recommendations
The status of implementation of pending PCSC recommendations (up to 71st PCSC meeting) is given at Annexure-II. The latest status on the same may please be sent latest by 09.02.2018.
Agenda for the 71st Meeting of PCSC scheduled to be held on 31
st January, 2018 Page 2
4.2 Remedial measures for "Transmission Elements under Forced Outage"
The Constituents are requested to furnish the remedial measures/ action taken by them for the tripping events as circulated vide our emails. (Annexure-III)
The tripping events are based on the daily reports at SRLDC website http://srldc.in/Reports.aspx under the menu: Reports->Daily-> "TL under Forced Outage")
4.3 Certificate for Healthiness of Batteries
As per the MoP 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 the monthly certificate for healthiness of batteries, installed at 220 KV and 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 have been 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 Secretariat.
The sought status for the months of January, 2018 is awaited from the following SR-Constituents:
KPTCL, TANGEDCO, TANTRANSCO, KSEBL, PED, PGCIL (SR-I) & TPCIL
5. TSTRANSCO’s SPS proposals at 220kV Sivarampally and 220kV Gachibowli
substations
TSTRANSCO vide their letter dated 14.02.2018 (Annexure-IV) has proposed for implementation of SPS schemes at 220kV Sivarampally and 220kV Gachibowli substations to avoid cascade tripping of the following lines during contingency:
1. 220kV HIAL – Sivarampally 2. 220kV Mamidipally – Sivarampally 3. 220kV Shankarpally – Gachibowli feeders-1 4. 220kV Shankarpally – Gachibowli feeders-2
The effectiveness & appropriateness of the schemes will be discussed during the meeting. TSTRANSCO and SRLDC are requested to present their case so that a call can be taken w.r.t. their implementation.
6. PMS: Protocol on using PDMS
You are kindly aware that Protection Management System (PMS) under implementation for Southern Region consists of two parts, viz., (i) Web-based Protection Data Management System (PDMS), and (ii) Desktop-based Protection Setting Calculation Tool (PSCT). While PSCT is the Calculation software for carrying out various studies (load-flow, short-circuit, transient stability, protection settings coordination), PDMS is an Asset Management Tool for maintaining information on relay attributes and settings. PDMS is a workflow driven web-based system with role-based access control. In the meeting, protocol on using PDMS will be presented.
Agenda for the 71st Meeting of PCSC scheduled to be held on 31
st January, 2018 Page 3
7. Other Protection Issues, if any, with the permission of the Chair
8. Sending Agenda items for the PCSC meetings
As per the Guidelines of CEA/MOP, it has been decided to conduct the PCSC meetings on monthly basis. It is requested that Agenda Items for the PCSC meetings, if any, may please be sent latest by 5th working day of the month to SRPC Secretariat to compile and circulate the same so as to have fruitful discussions in the PCSC meetings.
9. Date of next PCSC meeting
It is informed that the 73rd meeting of PCSC will be held on 26th April, 2018 (Thursday) from 10:30 hrs onwards in the Conference Hall of SRPC Secretariat, Bengaluru.
*****
Grid Occurrences to be discussed in the 72nd Meeting of PCSC scheduled to be held on 15th March, 2018 1/4
Grid Occurrences - 72
For all tripping events involving failure of substation equipment, Constituents are requested to kindly furnish the SLD or equivalent pictorial representation showing (i) Location of the fault, and (ii) Bus-bar arrangement/ Configuration of feeders and other connected equipment with proper CB positions (OPEN/ CLOSE) at the time of occurrence of the fault.
I. Details of Grid Disturbances:
Sl. No.
Details of Event Date &Time Reason Remarks Category
1
Complete outage of 230kV Mywadi SS of TANTRANSCO
10-01-2018 at 2:27hrs
Bus tripping got extended to 230kV Bus at 230kV Mywadi substation due to actuation of LBB protection during a Y-phase to earth faultin 230kV Mywadi- Kadamparai-2 feeder. All 230 feeders (10 Nos) and 400/230kV ICT LV’s-1, 2 & 3 got tripped during the incident.
---- GD-1
2
Complete outage of 400kV UV Konda Substation of APTRANSCO
20-01-2018 at 4:48 hrs
400kV UV Konda- Jammalmadugu line-1 tripped at 4:48hrs due to Y-phase to ground fault at both the ends. 400kV UV Konda Jammalmadugu line-2, Mahabubnagar line-1 and 2 were in open condition due to high voltage. After the tripping of 400kV UV Konda- Jammalmadugu line-1, 400/220kV ICT #1,2,3 and 4 at 400kV UV Konda were hand tripped due to loss of evacuating lines.
Gen Loss: 180MW
GD-1
3
Complete outage of 220kV TK Halli, Kadakola, Chamarajanagara and Maduvinahally substation of KPTCL
27-01-2018 at 12:41 hrs
Snapping of B phase Jumper in 220kV Bastipura-Kadakola line-1 resulted in tripping of the line. 220kV Bastipura-Kadakola line-2 also got tripped during fault in line-1. Due to tripping of above lines bus shutdownoccured at TK Halli, Madhuvanahally, Chamarajanagara and Kadakola stations due to overloading of connected lines.
Load Loss: 450MW
GD-1
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 SedamChittapur 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.
Load Loss: 410MW
GD-1
Annexure-I
Grid Occurrences to be discussed in the 72nd Meeting of PCSC scheduled to be held on 15th March, 2018 2/4
5 Complete outage of 230kV Hosur SS of TANTRANSCO
19-02-2018 at 01:41 hrs
Triggering incident was failure of Y phase HV CT in 100 MVA Auto Transformer – 3. Bus Bar Protection operated and all the 230kV feeders &Auto Transformers connected in 230kV Bus got tripped.
Load Loss: 174 MW
GD-1
II. Details of Grid Incidents:
Sl. No. Details of Event Date &Time Reason Category
1 Multiple Tripping at 400kV Raichur TPS.
05-01-2018 at 17:37 hrs
400kV Raichur TPS – Munirabad line tripped on operation of Zone-1 protection due to Y-N fault. 400kV RTPS-Raichur PG-1&2 tripped at RTPS end only on operation of stub protection
2 Tripping of HVDC Talcher-Kolar pole- 1.
08-01-2017 at 19:06 hrs
On 08-01-2017, pole-1 tripped due to burning of one of the Series Reactor in R-Phase of Pole-1. ESOF signal was received at Kolar. On 09-01-2018 Pole-1 tripped due to operation of Valve Cooling Differential Protection at Talcher end. Emergency switch off (ESOF) was received at Kolar.
09-01-2017 at 07:50 hrs
3 Tripping of 400kV Srisailam-Narnoor line
11-01-2018 at 02:02 hrs
Tripped on operation of over-voltage protection at Srisailam and direct trip was received at Narnoor
26-01-2018 at 01:57 hrs
4 Tripping of 400/220kV Hoody ICT-3 and 400 kV Kolar-Hoody ckt-2
14-01-2014 at 17:42 hrs
Triggering incident was failure of Y-phase lightning arrestor of 400kV Hoody-Kolar ckt-2 at Hoody end. and 400kV Kolar – Hoody Circuit-2 tripped on operation of distance protection. At the same time 400/220kV, 500MVA ICT-3 at Hoody also tripped on earth fault protection.
5
Tripping of 400kV Neyveli TS2-Neyveli TS2 Exp-1 and 400kV Neyveli TS2-Pugalur line
14-01-2018 at 03:25 hrs
Triggering incident was B-phase to earth fault in 400kV Neyveli TS2-Neyveli TS2 Exp line-1 due to failure of insulator near tower no.1 at NLC TS2-Exp end. The line has a differential protection which resulted in 3 phase trip at both ends. At the same time over-voltage protection got operated in 400kv Neyveli TS2- Pugalur line-1 at NLC TS-2 end and direct trip was received at Pugalur
6 Tripping of 400/220 kV Vemagiri ICT-2
14-01-2018 at 07:00 hrs
Tripped due to mal operation of B phase instantaneous over current relay. 400kV Vijayawada-Vemagiri also tripped due to B-phase to earth fault
Annexure-I
Grid Occurrences to be discussed in the 72nd Meeting of PCSC scheduled to be held on 15th March, 2018 3/4
7 Tripping of 400kV KTPS VI-Khammam line-2
14-01-2018 at 12:14 hrs
On both the days line got tripped at KTPS end and was holding from Khammam. At KTPS end breakers got tripped due to operation of 96 B lockout relay
18-01-2018 at 18:37 hrs.
9 765/400kV ICT#1 and ICT#2 at Vemagiri.
19-01-2018 at 18:38 hrs
Tripped due to mal-operation of Group A&B relays due to DC earth fault while carrying out testing of new 400kV CB timings
28-01-2018 at 11:59 hrs
10 Tripping of HVDC Gazuwaka pole-1
31-01-2018 at 06:38 hrs
Due to fault in 220kV line, ICT-1 at Gazuwaka got tripped due to directional OC high set. Since tertiary of ICT-1 was feeding the auxiliary supply to pole-1, tripping of ICT-1 led to the tripping of pole-1 due to loss of auxiliary supply
11 Tripping of HVDC Gazuwaka pole-2
01-02-2018 at 00:23 hrs
Pole 2 tripped due to the activation of “WA2 Ferro Resonance Detected" in East side.
12 Multiple Tripping at 220kV Gajwel substation
01-02-2018 at 16:13 hrs
B phase to earth fault due to earth rod not removed after maintenance work, 220kV Busbar-1 protection acted. All elements connected to Bus-1 tripped. 220/132kV , 160MVA ICT-2 connected to Bus-2 also tripped due to Over Load.
13
Tripping at 400kV Raichur PG -Raichur TPS line 1 and 2
05-01-2018 at 17:15 hrs
While carrying out bus bar scheme checking, RTPS-Raichur PG 1 and RTPS-Raichur PG 2 lines tripped at Raichur PG end. Direct Trip (DT) was received at RTPS end. Bus-1 was under shutdown.
14
Tripping of FSC of Both circuits of Jeypore -Gazuwaka due to Ferroresonance
08-02-2018 at 16:02 hrs
FSC of both circuits of 400kV Jeypore- Gazuwaka got bypassed due to ferroresonance.
15 400kV Gooty – NPS Ckt-2
15-02-2018 at 16:30 hrs
Line tripped due to Tie CB LBB relay mal-operation.
Annexure-I
Grid Occurrences to be discussed in the 72nd Meeting of PCSC scheduled to be held on 15th March, 2018 4/4
III. Details of Trippings due to Failure or Non-operation of Auto-Reclose:
Sl. No. Element Date & Time Reason
1 Tripping of 400kV YTPS-BTPS line
11-01-2018 at 6:17 hrs
Line tripped on B-ph to earth fault. Line did not auto-reclose
2 Tripping of 400kV Vemagiri-Simhadiri line-1
15-01-2018 at 05:19 hrs
B-phase to earth fault had occurred in line. At Simhadri end relay sensed fault in Zone-2 in B phase and tripped in zone-2 time due to non-receipt of carrier from Vemagiri. At Vemagiri, auto-reclose was attempted and same was un-successful.
3 Tripping of 400kV Sriperambadur-Chitoor line-1
15-01-2018 at 01:02 hrs
B-phase to earth fault had occurred in line. Auto-reclose was successful at Sriperambadur and auto-reclose did not operate at Chittoor end leading to all breaker poles opening at Chittoor
4 Tripping of 400kV Cudappah-Chitoor line
28-01-2018 at 16:03 hrs
B-phase to earth fault had occurred in line. Auto-reclose was successful at Chittor end & breakers at Cudappah end got tripped. After auto-reclose line was holding from Chittoor end
5 Tripping of 400kV 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
6 Tripping of 400kV Hassan-Nelamangala line
17-02-2018 at 15:21 hrs
Tripped due to B-phase to earth fault. Auto-reclose attempt was un-successful at Hassan and protection at Nelamangala did not attempt auto-reclose
7 Tripping of 400kV Srisailam-Dindi ckt-1
14-02-2018 at 07:11 hrs
Tripped on Y-Phase to Ground fault. Auto-reclose was disabled.
8 Tripping of 400kV Nelamangala-Hassan line
14-02-2018 at 14:22 hrs
Tripped on B-phase to ground fault. Auto-reclose unsuccessful
IV. Details of Trippings due to PLCC mal-operation:
Sl. No. Element Date & Time Reason
1 Tripping of 400kV Mamidapalli-Dindi line-2
09-01-2018 at 11:29 hrs
Line tripped on Direct Trip receipt at Mamidipally end and line was in service from Dindi.
2 Tripping of 400kV Mamidapalli-Dindi line-2
10-01-2018 at 14:43 hrs
Tripped at Dindi end only on Direct Trip received indications. DT was sent from Mamidipally end
3 Tripping of 400kv Dichipally – Nizamabad line-1.
11-01-2018 at 12:25 hrs
Line tripped at Dichipally end only due to spurious DT received at Dichipally. No counter increment was observed at Nizamabad end. Line was holding from Nizamabad end.
*****
Annexure-I
Meeting
No / Index
Details of Event Date & Time Reason PCSC Recommendations Utility
responsible for
Implementation
Status of Implementation of PCSC Recommendations Remarks
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)
40/II/3 Tripping of 400
kV TALAGUPPA
– HASSAN line
On account of R-phase to earth fault, line tripped at
Hassan end due to operation of distance Zone-2 and non-
receipt of carrier. From D.R of Talaguppa end it is
observed that fault had occurred in Yphase.
1. PGCIL and KPTCL to ascertain the reason for the phase discrepancy in the relay
operation and take suitable remedial measures.
2. KPTCL to check the PLCC operation at Talaguppa end and submit the report to
the PCSC forum.
PGCIL (SR-II)/ KPTCL PendingMail recieved on 28-04-2015:
1. --- Pending
2. End to end testing of PLCC has been done and problem in the PLCC is atttended. --- Completed
Mail received on 27-05-2015 (KPTCL) & 29-07-2015:
1. Phase discrepancy in the relay operation is to be checked jointly. --- Pending
2. End to end testing of PLCC has been done and problem in the PLCC is atttended. --- Completed
Mail recieved on 02-09-2015 from PGCIL (SR-II):
1. Problem is in identification of phases at Talguppa end. To be rectified by M/s KPTCL. ----- Pending
Mail recieved on 28-06-2016 from KPTCL:
1. The matter is reffered to the concerned Operation and maintance wing to set right the mismatch of phases in 400kV Talaguppa-
Nelamangala and Talaguppa-Shantigrma lines at Talaguppa in cordination with PGCIL . --- Pending
KPTCL Mail dated 16.12.2017:
1. Shut downs have be planned.PGCIL coordination is required.
--- Pending
Review Meeting dated 19.12.2017:
1. KPTCL informed that the required work in proposed to be carried out on HV (400 kV) side. Tedners for the same would be called by
February, 2018, and the work is targeted to be completed by August, 2018. --- Pending
01-01-2015
at 13:38 hrs
Status of Pending Implementation of PCSC Recommendations as on 26.02.2018 (up to 71st 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.
Multi-Utilities
16-07-2014
Annexure-II
Page 1 of 34
Pending
[with
PGCIL (SR-I)]
APGENCO/
PGCIL (SR-I)
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.
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
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.
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.
PGCIL-SR1 RVMD 14-07-2016:
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 (SR-I) Mail dated 15.12.2017:
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.
Review Meeting dated 19.12.2017:
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.
47/I/2
Annexure-II
Page 2 of 34
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.
4. Procurement of differential protection for 400kV NPS-NLR D/C and 400kV RCR-RTPS-D/C is 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:
4. 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 --- Pending
PGCIL (SR-I) Mail dated 15.12.2017:
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.
Review Meeting dated 19.12.2017:
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.
31-07-2015 at
11:44 hrs
KPTCL/ KPCL/
NPCIL (KAPS)
1. KPTCL/ KPCL to see the possibility of implementing Weak Infeed logic with
Echo feature enabled by Under
Voltage (27) element on Kadra-Karwar lines 1 &2, and implement the same if
feasible.
2. NPCIL to time-coordinate Kaiga’s DEFR settings with (i) Zone-2 settings at
Kaiga, and (ii) primary protections of the lines emanating from Kadra and
Kodasalli.
3. KPCL to ensure time-sync of EL’s, and healthiness of the Fault Locators at
Kadra.
220kV Kadra-Karwar lines-1&2 tripped
on earth fault in B-phase in zone-2.
Kaiga-Kadra line tripped at Kaiga end
only on operation of directional eath
fault protection.
Tripping of 220 kV Kadra-Karwar lines -
1&2 and 220kV Kaiga-Kadra line
47/II/7 KPTCL Mail recieved on 25-05-2016:
1. Availability of week end infeed with eco feature to be confirmed by SEE,RTC,Hubli --- Pending.
NPCIL (KGA) Mail recieved on 03-12-2016:
2. The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga Kodasally lines were disabled. IDMT DEFR is retained. The
200 ms Definite time back up o/c element in both Kaiga Kadra and Kaiga Kodasally lines were disabled. IDMT is retained. ---
Completed.
Status received vide KPCL mail dated 14.06.2017 & 29.11.2017:
1. Since PT blasted (B phase) at Karwar end, resistive over reach occurred. hence Backup protecion operated at Kadra end (zone-2 not
sensed) --- Pending.
2. ---- Completed
3.Newly commissioned micom P444 relay time synchronised with GPS ------ Completed.
KPTCL Mail dated 16.12.2017:
1. Week end infeed logic will be enabled in the new numerical relays supplied to Karwar under R&U during retrofitting works.
--- Pending
Review Meeting dated 19.12.2017:
1. KPTCL informed that since the line is a double circuit, there may not be need for implementing Weak Infeed logic with Echo feature
at Karwar end. However, the same would be looked into w.r.t. the newly commissioned NR's at Karwar, and final action taken would
be informed by March, 2018.
Pending
[with KPTCL]
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.
PGCIL (SR-I),
MEPL, SEL, TPCIL,
NCC
PendingComplete outage of TPCIL power station 30-12-2015 at
06:02hrs
Running 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
50/I/2
Annexure-II
Page 3 of 34
PGCIL mail received on 27-04-2016:
Being pursued with APTRANSCO
APTRANSCO mail dated on 22-06-2016:
AS maintenance being carrired out by PGCIL(SR-1), the required relay replacement (wiring/programming) may also be carried out by
PGCIL(SR-1).
PGCIL RVMD 14.07.2016:
1. The CB problem has been attended by POWERGRID by using OEM M/s BHEL services & POWERGRID's O&M spares.
------ Completed.
2. Being pursued with APTRANSCO to replace the faulty Event Logger at Vijayawada (Nunna) SS. ---- Pending
APTRANSCO mail dated on 31-08-2016 & 04.03.2017 & 24.05.2017:
As maintenance being carrired out by PGCIL(SR-1), the required relay replacement (wiring/programming) may also be carried out by
PGCIL(SR-1).
APTRANSCO mail dated 20.10.2017:
May be coordinated with PGCIL
APTRANSCO mail dated 22.11.2017:
PGCIL may be requested to take necessary action
APTRANSCO mail dated 15.12.2017:
2. EL procured and drawn. Configuration to be done by Alstorm company engineer. Will be configured in four weeks.
---Pending
PGCIL (SR-I) Mail dated 15.12.2017:
2. APTRANSCO is to replace the faulty/outdated relays & POWERGRID has to maintain the relays after retrofitting.
Review Meeting dated 19.12.2017:
2. APTRANSCO informed that the recommended works would be completed in one-month period.
APTRANSCO Mail dated 30.01.2018
As per the requirement of PGCIL.Event logger(BCU) with data base is configured and handed over to PGCIL/Nunna on 27 th dec
17.PGCIL is requested to take action for taking event logger (BCU) into service.
56/I/2 Complete outage of 220kV Sedam
Substation of KPTCL.
19-06-2016 at
15:27hrs
220kV Sedam-Humnabad-2 tripped at Sedam on
Distance protection, Zone-2. Sedam-RTPS-1 &2 lines
tripped at RTPS end only. 220kV Tandoor inter-state line
was hand tripped due to incoming supply failure
KPTCL and TSTRANSCO to take steps to provide A/R feature on 220 kV Sedam –
Tandur inter-state line at their respective ends at the earliest.
KPTCL/
TSTRANSCO
KPTCL Mail dated 16.12.2017:
Carrier protection is to be restored. B/U OC and EF relay is to be replaced by M-II distance relay. Required materials like wave trap,
M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd. --- Pending
Review Meeting dated 19.12.2017:
TSTRANSCO informed that they have kept A/R in service from Tandur end. 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.
Pending
[with KPTCL]
PGCIL (SR-I)/
APTRANSCO
Pending
[with APTRANSCO]
1. PGCIL (SR-I), in co-ordination with APTRANSCO, to address the problem with
CB at the earliest opportune time.
2. APTRANSCO to take steps to replace the faulty Event Logger at Vijayawada
(Nunna) SS.
51/II/6 Line tripped due to operation of over voltage protection
at Vijayawada end and Direct Trip was received at
Sattenapalli end
25-12-2015 at 3:01
hrs
Tripping of 400kV Sattenapalli-Vijayawada
line
Annexure-II
Page 4 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.
APTRANSCO mail dated on 15-11-2016:
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.
APTRANSCO mail dated on 20-12-2016:
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 action
APTRANSCO 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
Review Meeting dated 19.12.2017:
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.
56/III/4 Tripping of 220 kV Sedam-Tandur line 03-06-2016
at 21:52 hrs
Line tripped on B-phase to earth fault. Auto-reclose is not
enabled for line.
KPTCL and TSTRANSCO to fast-track providing A/R on 220 kV Sedam – Tandur
line, and furnish an action plan of providing the same by next PCSC meeting
(PCSC-57).
KPTCL/
TSTRANSCO
KPTCL Mail dated 16.12.2017:
Carrier protection is to be restored. B/U OC and EF relay is to be replaced by M-II distance relay. Required materials like wave trap,
M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd.
Review Meeting dated 19.12.2017:
TSTRANSCO informed that they have kept A/R in service from Tandur end. KPTCL informed that the works relating to put A/R in
service are gonig on at their Sedam SS, and assured that it would be put into service by February, 2018.
TSTRANSCO MAIL DATED 20.01.2018:
As discussed in the review meeting on 19-12-2017, A/R is kept in service from Tandur(TSTRANSCO) end.---Pending
Pending
57/I/1 Complete outage of 220 kV Karwar
Substation of KPTCL
12-07-2017
at 11:36 hrs
Triggering incident was failure of R phase PT in Bus-1 at
220kV Karwar substation. 220kV Kaiga-Kodasalli tripped
during the incident. Also bus shut down occurred at
Kadra and Kodasally stations.
1.NPCIL (KAPS) to disable DefiniteTime O/C relay, and put in its place by IDMT
O/C relay for backup protection on both 220 kV Kaiga – Kadra line and 220 kV
Kaiga – Kodasalli line at Kaiga end.
2.KPTCL to put bus bar protection in service at their 220 kV Karwar SS at the
earliest.
3.KPCL/ KPTCL to implement Weak In-feed Logic with Echo feature enabled by
Under Voltage (27) element on Kadra – Karwar lines 1 & 2.
4.KPTCL to furnish equipment failure report of the current incident to PSE&TD
Division of CEA with a copy marked to SRPC.
KPTCL/ KPCL/
NPCIL (KAPS)
NPCIL(KGS) mail dated on 03-12-2016 & 29.11.2017:
1.The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga Kodasally lines were disabled. IDMT DEFR is retained. ---
Completed
2. --- Pending
3. --- Pending
4. --- Pending
KPTCL Mail dated 16.12.2017:
2) Bus-bar protection panel is supplied under R&U. Replacement work will be taken up after priority Sub stations.
--- Pending
3] Weak end Infeed logic available in new relays supplied; Will be enabled During R&U works. --- Pending
4] Equipement failure reports are being sent to CEA regularly.
--- Completed
Review Meeting dated 19.12.2017:
2. KPTCL informed that the works relating to providing BBP are targeted to be completed by March, 2018.
3. KPTCL informed that since the line is a double circuit, there may not be need for implementing Weak Infeed logic with Echo feature
at Karwar end. However, the same would be looked into w.r.t. the newly commissioned NR's at Karwar, and final action taken would
be informed by March, 2018.
Pending
[with KPCL & KPTCL]
Pending24-06-2016 at 16:04
hrs
APTRANSCO/
PGCIL (SR-I)
56/II/13 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
Tripping at 220 kV Gooty Substation of
APTRANSCO
Annexure-II
Page 5 of 34
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.
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
APTRANSCO mail dated on 20-12-2016:
Issue was addressed to the concerned for necessary action.
APTRANSCO mail dated on 24-05-2017:
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.
PGCIL (SR-I) Mail dated 15.12.2017:
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.
Review Meeting dated 19.12.2017:
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.
APTRANSCO MAIL DATED 30.01.2018
Technical & financial bids are opened. Tenders will be awarded shortly.
Pending57/II/9
Annexure-II
Page 6 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
64/I/2 Complete outage of North Chennai TPS
STG-2
25-04-2017
at 18:27hrs
Tripping of evacuating lines due to fault led to tripping of
Unit
64/I/3 Complete outage of North Chennai TPS
STG-2
26-03-2017
at 21:09 hrs
Tripping of evacuating lines due to fault led to tripping of
running Unit at NCTPS Stg-2
66/ II/ 5 Tripping of 400 kV Ramagundam -
Dichipally line, 400kV Nizamabad -
Dichipally line-1 and 400/220 kV ICT-1
05-06-2017 at 19:15
hrs
Triggering incident was fault in 400kV Nizamabad GIS 1. TSTRANSCO/ NTPC to adopt proper Zone-2 time settings (say, Ramagundam
end --> 500 msec; Dichipally end --> 350 msec in line with Ramakrishna
Committee recommendations) on 400 kV Ramagundam – Dichipally line and 400
kV Dichipally - Nizamabad lines respectively.
2. For the 400 kV Dichipally - Nizamabad D/C line, TSTRANSCO, in coordination
with PGCIL (SR-I), to carry out the following:
(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.
NTPC-
Ramagundam/
TSTRANSCO/
PGCIL (SR-I)
PGCIL (SR-I) Mail dated 15-12-2017:
1. In 400kV Nizamabad-Dichpally lines Zone-2 trip time delay of 0.35 sec was already implemented at Nizamabad end.
2. For 400kV NZB-Dichpally D/C lines PLCC commissioned with LDP relays & Line-1 tested on 16.09.2017 & Line-2 tested on
17.09.2017 found ok. --- Completed
Review Meeting dated 19.12.2017:
1. It was agreed that TSTRANSCO would provide revised settings to NTPC-Ramagundam for implementation in one-week time.
In this regard, PCSC forum also asked TSTRANSCO to revise their Zone-2 settings of their 220 kV & 400 kV lines in line with
Ramakrishna Committee guidelines. To this, TSTRANSCO replied in affirmative and assured that they would comply with the same by
January, 2018.
TSTRANSCO MAIL DATED 20.01.2018:
1. Revised relay settings for Dichpally-Ramagundam line is given as per the Lr.No.CE/PS/SE/PS/SP-1/111/Relays 400kV Dichpally/Vol-
2/D.No. 11/18, Dt:18-01-2018. As per the Ramakrishna Committee guidelines and same will be adopted in field in coordination with
NTPC/PGCIL and based on Line Clearance availability.
2. Instructions for revising Zone-2 settings for 220kV and 400kV lines will be issued to the concerned field officials shortly. ---Pending
NTPC Ramagundam MAIL DATED 13.02.2018:
Zone -2 timing implemented at NTPC end is 0.4 Sec. Same has been communicated to TSTRANSCO on 30/01/2018.
Pending
TANTRANSCO/
PGCIL(SR-II)
Pending
[with TANTRANSCO]
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.
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.
Review Meeting dated 19.12.2017:
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.
TANTRANSCO MAIL DATED 25.01.2018:
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.
Annexure-II
Page 7 of 34
1. --- Pending with TSGENCO
PGCIL (SR-I) Mail dated 15-12-2017:
2). TOR feature in MiCOM P444 relay enabled for 400kV KMM-KTPS lines at Khammam end. DT send on TOR trip is not as per
protection philosopy. However if SRPC/SRLDC gives separate instructions exclusively for this line, the same shall be imoplemented
after getting our CC approval. --- Pending
3). At Khammam SS all DR & ELs are time synched. --- Completed.
4). --- Pending
TSGENCO Mail dated 18.12.2017:
1). If the auto reclose function dead time kept same at both ends as 1 sec uniformly. In case of persistent fault, it leads to feed the
fault from both ends and cause the generator breaker switching on to high fault current and chances of pole slip. To avoid this time
differentiated A/R scheme to be implemented. In KTPS 400KV Line –I & II at KTPS end dead time is 1.2sec and at KMM end it is 1sec.
In our relay 7SA522 does not have the adaptive dead time function A/R. Hence, it is requested to send DT in case of on 3-phase trip
and A/R unsuccessful at KMM end to avoid reclose attempt from KTPS end after dead time (1.2Sec) for persistent faults.
We communicated to M/s Siemens to upgrade the firmware version regarding adaptive dead time.
Hence, it is requested to review these settings to reduce the stress on Generating Station --- Completed
Review Meeting dated 19.12.2017:
2. It was made clear to PGCIL (SR-I) that this is a specific case of those 400 kV lines where one one of the ends is a generating station,
and the other end is grid-connected substation having TOR feature in line protection relays. The said recommendation of enabling
TOR along with sending DT to the other end is basically to ensure safety of Generating Units at the other end. Accordingly, PGCIL (SR-I)
was asked to take steps to ensure the same. --- Pending
4. PGCIL (SR-I) informed that shutdown was availed by TSGENCO on 14.12.2017, and all issues relating to PLCC including end-to-end
testing were carried out. --- Completed
TSGENCO/
PGCIL (SR-I)
1. TSGENCO to keep uniform A/R dead-time of 1 sec on the lines emanating from
their KPTS station.
2. PGCIL (SR-I) to enable Trip-on-Reclose (TOR) functionality for Zone-2 faults for
Khammam – KTPS lines at Khammam end, if such a feature is available in the
concerned relay, and to configure it for sending Direct Trip (DT) Command to
KTPS end.
3. PGCIL (SR-I) to set right time-sync issues w.r.t. Khammam end Event Loggers on
Khammam – KTPS lines.
4. For 400 kV Khammam – KTPS line-1, PGCIL (SR-I), in coordination with
TSGENCO, shall carry out the following:
(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.
08-06-2017 at 18:32
hrs
66/ II/ 8 Tripping of 400 kV Khammam – KTPS lines
– 1 & 2
Lines – 1 & 2 tripped on B-phase to earth faults Pending
[with
PGCIL (SR-I)]
Annexure-II
Page 8 of 34
66/ II/ 10 Tripping of 400/ 220 kV ICT’s – 3 & 4 at
Ramagundam STPS
11-06-2017
at 19:46hrs
Triggering 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.
NTPC-
Ramagundam/
TSTRANSCO
NTPC mail dated 07.12.2017:
1. High set DEFR on 220 KV lines is disabled ----Completed
2. ---- Pending
Review Meeting dated 19.12.2017:
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.
Pending
68/I/2 Complete outage of 220 kV Kadra Power
Station of KPCL.
25-09-2017
at 11:41hrs
Triggering incident was tripping of 220 kV Kadra-Kodasalli
and 220 kV Kadra-Kaiga line. There was no generation at
Kadra in antecedent condition.
1. KPCL to investigate the reasons for non-tripping of 220 kV Kadra – Kodasalli
line from Kadra end by any of the Main protection relays, and opening of only B-
ph pole at Kodasalli end, and furnish an action taken report on the same.
2.KPCL to sort out issues relating to downloading of DR’s & EL’s at Kadra PH at
the earliest.
3. KPCL to use both the 220 kV buses as main buses under normal operation, and
to go for single bus operation only during emergencies at their Kadra PH.
4. NPCIL (KGS) to configure time resolution of Event Loggers to milli seconds at
their Kaiga GS.
KPCL/ NPCIL (KGS) 1. --- Pending
2. --- Pending
3. --- Pending
Status received vide NPCIL mail dated 29-11-2017:
4. The event logger(ESCADA) has inherent time resolution of 10 millisecond for digital inputs. In future higesht resultion event logger
history will be extratced for submission to grid authorities..--NPCIL-KAIGA ----Completed
Review Meeting dated 19.12.2017:
1). Kadra-kaiga 220KV line tripped on both end in Zone-1 distance protection. Fault distance is 0.9KM from kadra end. Kodasalli-Kadra
220KV tripped at Kodasalli end only in Zone-1 fault. Reason for tripping is the both Kadra-kodasalli, kadra-Kaiga line are in same
tower, hence same fault reflected adjuscent line. Because of no Bus source, Kadra end relay stopped to detect, hence Kadra end
breaker was intact.
---- Completed
2). Issue relating to downloading of DRs & Els at Kadra PH rectified. --- Completed
3). KPCL informed that they have planned to take up providing double-bus operation at their 220 kV Kadra PH, 220 kV Gersoppa PH,
and 220 kV Raichur TPS through PSDF funding, and DPR for the same is under preparation. After obtaining approval of the same from
their management, other activities inluding tenders floating, approaching PSDF would be taken up. All these activites are targeted to
be completed within 2 years.
--- Pending
Pending
Annexure-II
Page 9 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)
Review Meeting dated 19.12.2017:
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.
Pending
69/II/10 Tripping of 400 kV Hassan-UPCL line-1&2 13-10-2017 at 16:11
hrs
R-Y phase to earth fault in line-1 and R-phase to earth
fault had occurred simultaneously in Line-1 & line-2
respectively. Line-1 got tripped due to LLG fault. In Line-2,
auto-reclose was successful at Hassan and 3-phase trip at
UPCL.
For the line trippings under consideration, PGCIL (SR-II) and UPCL to furnish
relevant COMTRADE (.cfg & .dat) files to PCSC forum so that the same could be
analysed using PSCT software by PRDC for correct operation of the relays
involved.
PGCIL (SR-II)/ UPCL Yet to be informed Pending
69/III/3 Tripping of 400 kV Kurnool(PG) –
Kurnool(AP) line-2
02-10-2017 at 02:03
hrs
Line tripped on B-ph to ground fault. A/R was
unsuccessful at both Kurnool (AP) and Kurnool (PG) ends.
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.
APTRANSCO/
PGCIL (SR-I)
APTRANSCO maild ated 30.01.2018:
A/R scheme on 400kV Kurnool (PGCIL) feeder-2 will be checked after getting LC.
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
APTRANSCO maild ated 15.12.2017:
APTRANSCO would extend support and requirements if any ,for the rectification proposed by KPTCL.
Review Meeting dated 19.12.2017:
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 ated 30.01.2018:
APTransco world extend required support .
Pending
71/III/2 Tripping of 400 kV Suryapet-VTPS line 27-12-2017 at 14:39
hrs
Line tripped on Y-phase to earth fault. Zone-2 operated
at VTPS due to non-receipt of carrier
1. APGENCO and TSTRANSCO to put A/R into service from their respective ends
on 400 VTPS – Suryapet line.
2. For the line under consideration, the following shall be carried out by
APGENCO, in coordination with TSTRANSCO:
(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.
APGENCO/
TSTRANSCO
Yet to be informed Pending
52/I/2 (GD) Complete outage of 220 kV Yerraguntla
substation and tripping of running Units at
Rayalaseema TPS
21-02-2016 at 10:39
hrs
HV B-Ph Current transformer of 100MVA Power
Transformer -1 failed resulting into a bus fault on 220KV
Bus-1. Unit-1 and Unit-5 at RYTPS tripped during the fault
at Yerraguntla substation
1. APGENCO to check associated logic for lube oil pump for correct operation
under transient low voltage conditions at Rayalaseema TPS, Unit-1.
2. APGENCO to keep appropriate time delay/ fault ride through delay (typically 2
sec) in VFD speed sensor relay at all its generating Units including Rayalaseema
TPS Units.
APGENCO Mail received on 27-07-2016:
1.The drop out relays of reducer oil pumps time setting was increased for all mills.So there will not be any trip under transient low
voltage condition.----Complied
2.The recommendation regarding 2 sec time delay will be implemented during unit shut down and will be intimated immediately after
implementation.------Pending
Review Meeting dated 19.12.2017:
It was noted that no APGENCO representative had come to attend the meeting.
Pending
Andhra Pradesh
Annexure-II
Page 10 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
Pending
69/II/1 Multiple trippings at Tripping at 220 kV
Srisailam Right Bank power station
09-10-2017 at 14:39
hrs
220kV Srisailam RB – Markapuram S/C line and 220 kV
Srisailam – Podili S/C line tripped on operation of
distance protection. Srisailam Units - 3, 4, 6 and 7 got
tripped during the incident.
1.APGENCO to furnish compliance report on the recommendations given by
PSAG-9 team that had visited Srisailam RB PH on 14-15 October, 2014.
2.APGENCO to carry out the following:
(i)Removal of DC earth leakage in station switchyard on priority basis (latest by
10.12.2017)
(ii)Integration of Station earth-mat and Switchyard earth-mat.
3. APGENCO to provide for numerical relays (as both Main-I & Main-II) on all 220
APGENCO Yet to be informed Pending
68/III/9 Tripping of 400 kV Kalpaka – Asupaka line 29-09-2017 at 10:48
hrs
Y-phase to earth fault. Auto – reclose was stated to be
successful at Kalpaka end. At Asupaka end Auto-reclose
had not operated due to problem in configuration
settings.
For the subject line relay at Kalpaka end, APTRANSCO to configure DR for a post-
triggering period of 2 sec and EL for all required protection (analog & digital)
events
APTRANSCO APTRANSCO Mail dated 15.12.2017:
Post triggering period of 2 see for DR is configured. Wiring under the scope of retrofitting works is being carryout by EMC. EL will be
configured on completion to wiring works.
Review Meeting dated 19.12.2017:
APTRANSCO informed that the recommedned works would be completed by 31.01.2018.
APTRANSCO maild ated 30.01.2018:
Informed to EMC to complete retrofitting work on top priority
Pending
69/II/7 Tripping of 400 kV Uravakonda –
Jamalamadugu line-1
06-10-2017 at 10:22
hrs
Line tripped on overvoltage at Uravakonda end and
Direct Trip received at Jamalamadugu end. DR & EL of
Uravakonda end not furnished.
APTRANSCO to complete configuration of DR’s & EL’s for all protections relays at
their 400 kV Uravakonda SS, and render them suitable for
extraction/downloading of relevant tripping records/ events within a month’s
time.
APTRANSCO APTRANSCO Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:
Instructions were issued for taking necessary action.
APTRANSCO maild ated 30.01.2018:
Configuration of DR & EL’s in the relays completed configuration of DR & EL at SAS is to be verified.
Pending
Annexure-II
Page 11 of 34
61/III/5 Tripping of 400 kV Khammam - KTPS line-2 24-12-2016 at 10:52
hrs
Line tripped on B-phase to earth fault. First fault was
persistent for 380 ms. Auto-reclose was successful at
Khammam end during 1st fault. 2nd fault occurred during
re-claim time of breaker hence Khammam end breakers
also got tripped.
1. TSGENCO to implement the SRPC agreed philosophy for Power Swing Blocking
in all distance relays on the feeders emanating from KTPS.
2. For the line under consideration, TSGENCO to consult relays OEM to migrate
to new versions of Firmware (from 4.68.03 to 4.72.01) and Pset (from 4.63.04 to
4.70.02).
TSGENCO TSGENCO mail dated 30.03.2017:
1. According to SRPC phylosphy power swing block settings are changed to ALL ZONES BLOCK EXCEPT ZONE1.
---------- Completed
2. M/s. Siemens is requested to depute the service Engineer to update the firm ware of existing SIPROTEC relays in 400KV switch yard.
This work will be completed on or before 15.04.2017.
----------- Pending
TSGENCO mail dated 08.12.2017:
1. --- Completed
2. As this KTPS line-II is being LILOed at KTPS, Stage-VII, those relays would be replaced with line diff relays. --- Pending
Review Meeting dated 19.12.2017:
As recommeded, TSGENCO was asked to migrate to new versions of firmware in consultation with relays OEM.
------- Pending
Pending
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
67/III/1 Tripping of 400 kV Gajwel - Bhoopalapalli
line
22-07-2017 at 13:13
hrs
Line tripped on B-ph to earth fault. Auto-reclose was
successful at Bhoopalapally end and breaker tripped at
Gajwel.
1. For the line under consideration, TSTRANSCO to sort-out A/R related issues at
Gajwel end.
2. For the line under consideration, TSTRANSCO to configure EL at Gajwel such
that PDR operation is also captured in it.
3. TSTRANSCO to configure DR’s of protection relays at their Gajwel SS for a post-
triggering period of 2 sec so as to capture complete A/R operation.
TSTRANSCO Review Meeting dated 19.12.2017:
1) & 2) & 3) TSTRANSCO informed that given reocmmendations would be complied with by 10.01.2018
TSTRANSCO MAIL DATED ON 20-01-2018:
Line Clearance could not be availed on 10-01-18 as company engineer could not come as per Schedule. It is proposed to carry out
End to end testing on 29-01-18 by availing Line clearance.
Pending
69/III/1 Tripping of 400 kV Gajwel - Narsarpur line 01-10-2017 at 03:55
hrs
Tripped on B-phase to earth fault. Auto-reclose attempt
could not be validated with submitted DR of both ends
and from PMU data plot.
TSTRANSCO to configure DR’s and EL’s of Protection relays at their 400 kV Gajwel
SS and 400 kV Narsapur SS for proper time-scales and for recording all required
protection events.
TSTRANSCO TSTRANSCO MAIL DATED ON 20-01-2018:
Line Clearance could not be availed on 10-01-18 as company engineer could not come as per Schedule. It is proposed to check Auto
reclosure function testing on 29-01-18 by availing Line clearance.
Pending
TSGENCO70/II/3 Tripping of 400 kV Satenapalli-Srisailam
line-1
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.
Yet to be informedTSGENCOTSGENCO 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.
Line tripped on operation of over-voltage protection at
Srisailam and Direct Trip was received at Sattenapalli.
Considerable voltage difference was observed between
R, Y & B phases at Srisailam end.
71/II/7
Telangana
Tripping of 400kV Kurnool-Srisailam line 70/II/2
Yet to be informed Pending
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
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.
TSGENCO Yet to be informed Pending
Pending
Annexure-II
Page 12 of 34
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.
Review Meeting dated 19.12.2017:
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.
Pending
62/IV/5 Tripping of 400 kV Gajwel-Bhoopalapalli
line-1
16-02-2017
at 15:00 hrs
Line tripped at Bhoopalapally on DT receive and was
holding from Gajwel.
For the line under consideration, TSTRANSCO to carry out the following in
coordination with TSGENCO:
(i) Healthiness of PLCC system components (hardware and software) at both ends
shall be checked and faulty components shall be repaired/ replaced.
(ii) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(iii) Frequency bandwidth tuning of PLCC link for faithful transmission of signals
shall be carried out.
TSGENCO /
TSTRANSCO
TSTRANSCO mail dated on 31-05-2017:
1. Letter is been given to field for conducting end to end testing of 400kV Gajwel-Bhoopalpalli-1 line --- Pending
TSGENCO mail dated 08.12.2017 & 19.12.2017:
TSGENCO/KTPP will make all the necessary arrangements for checking the end to end protection through communication system
prior to intimation by TSTRANSCO --- Pending
Review Meeting dated 19.12.2017:
TSTRANSCO informed that PLCC end-to-end testing would be carried out as recommended by 10.01.2018.
TSTRANSCO MAIL DATED ON 20-01-2018:
Line Clearance could not be availed on 10-01-18 as company engineer could not come as per Schedule. It is proposed to carry out
End to end testing on 29-01-18 by availing Line clearance.
Pending
Provision 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-II
Page 13 of 34
41/I/1 GD-1 at 220kV Kadra power Station of
KPCL
16-02-2015 at 12:56
hrs
Triggering incident was B-phase to earth fault had
occurred in 220kV Kadra-Kodasalli line. Line tripped from
Kodasalli end only. 220kV Kaiga-Kadra tripped in Zone-3
from Kaiga end. Tripping of evacuating lines caused bus
shut down at Kadra hydro station.
1. KPCL to make functional the Main2 (EPAC) relay with the help of KPTCL at
the earliest.
2. KPCL to investigate the reason for DC fuse fail during transient fault in
220kV Kadra-Kodasalli line including the testing/ checking of DC supply cables,
breaker control cables, and trip coils.
3. KPCL to ensure supply for Main-1& Main-2 protections, Trip Coils (TC1, TC2)
from separate battery banks.
KPCL Mail received on 28-05-2015:
1. Main-2 relays already installed and commissioned.
2. DC fuses are intact. Till date no such incidence occurred.
3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be reviewed.
Mail received on 07-07-2015 , 21-10-2015 and 23-11-2015:
1. --- Completed.
2. --- Completed.
3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be reviewed --- Pending
Status received vide KPCL mail dated 14.06.2017:
3. Providing 2 separate DC sources is under process --- Pending
Status received vide KPCL mail dated 14.12.2017:
3. Work under implementation stage --- Pending
Review Meeting dated 19.12.2017:
3. KPCL informed that for providing 2 separate DC sources with new battery charger, LOA & Work order were placed on M/s Eltek
Power system. The works would be completed in March, 2018. --- Pending
Pending
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.
3) 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. --- Pending
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.
Review Meeting dated 19.12.2017:
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.
Trippings at 220kV Raichur TPS
Karnataka
46/II/21 PendingKPCL1. 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.
07-06-2015 at 01:35
hrs
Annexure-II
Page 14 of 34
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
Review Meeting dated 19.12.2017:
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.
Pending
Status received vide KPCL mail dated 10.07.2017:
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.
Status received vide KPCL mail dated 14.12.2017:
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
.
Review Meeting dated 19.12.2017:
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
KPCL mail dated 19.01.2018:
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.
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.
Review Meeting dated 19.12.2017:
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.
Pending
58/I/3 (GD) Complete outage of 220 kV Kadra power
station of KPCL
06-09-2016
at 14:40 hrs
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
1) 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.
KPCL Status received vide KPCL mail dated 14.06.2017:
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
Review Meeting dated 19.12.2017:
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
Pending
Tripping of 400kV Raichur TPS
Bus-2
13-04-2016 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 PendingKPCL
Annexure-II
Page 15 of 34
62/I/1 Complete outage of 220 kV Nagjheri
substation of KPCL
21-01-2017
at 00:38 hrs
Triggering event was the fault on 220 kV Nagjheri
–Kodasalli line-2. Both buses of 220 kV Nagjeri power
station of KPCL got
de-energized.
1. KPCL to adopt the following VT fuse-fail logic for all 220 kV lines emanating
from NPH:
“Under VT fuse fail condition, distance protection shall normally be kept blocked.
However, upon detection of a fault (sensed by negative sequence component),
blocking of distance protection shall give rise to operation of its inherent Over-
Current protection set with a definite time delay of 500 msec”.
2. KPTCL/ KPCL to revise Zone-2, Zone-3 and Zone-4 (reverse) timings of DPR of
all 220 kV lines emanating from Nagjheri PH in line with Ramakrishna Committee
guidelines.
KPCL Status received vide mail dated 14.06.2017:
1. Already settings are discussed with EE(RT), Hubli and soon relays will be tested for VT fuse fail condition.
2. Timings of Zones were set as per the recommendations of CE(RT) & R&D, KPTCL, Bangalore & EE(RT), KPTCL, Hubli.Regarding
revision of timings will be carried out in co- ordination with EE(RT), KPTCL, Hubli.
Status received vide mail dated 14.12.2017:
1. As per the recommendations of SRPC and SRLDC, in the event of VT fuse fail, non directional over current and earth fault feature is
enabled in the distance relay with a definite time lag of 600msec on pick up and the same is tested by KPTCL Hubli(RT) and KPCL jointly
on 18.05.2017.
--- Completed
2. --- Pending
Review Meeting dated 19.12.2017:
2. KPCL informed that Zone settings of distance relays of all 220 kV lines emanating from Magjheri SS had been revised in line with
Ramakrishna Committee guidelines.. --- Completed.
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 Yet to be informed Pending
Mail received on 28-04-2015:
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 mode. Pending works will be completed within a months time.
KPTCL mail recieved on 23-01-2016:
1. Bus-II PTs yet to be commissioned.Planned to complete before end of April-2016.
KPTCL mail recieved on 25-04-2017 & 22.11.2017:
1. Yet to be attended --- Pending
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.
GD-1 at 220kV Ambewadi Station of KPTCL Triggering 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
40/I/1 PendingKPTCL1. 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.
Annexure-II
Page 16 of 34
Mail received on 28-04-2015:
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.
Mail received on 29-07-2015:
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.
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 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.
KPTCL Mail dated 16.12.2017:
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.
Review Meeting dated 19.12.2017:
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.
PendingComplete outage at 220kV Sedam
Substation of KPTCL (GD-1)
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.
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.
27-01-2015 at 8.00
hrs
41/I/4
Line tripped on Yphase to earth fault from both the ends20-12-2014
at 22:20 hrs
PendingMail recieved on 29-07-2015:
Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring the carrier protection , AR will be
enabled.
KPTCL mail recieved on 23-01-2016:
Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring the carrier protection , AR will be
enabled.
KPTCL mail recieved on 25-05-2016:
SEE,SCADA to update the latest status
KPTCL mail recieved on 28-06-2016:
Action is being taken to restore carrier protection.AR will be enabled once carrier signal is restored.
KPTCL Mail Recieved dated 22-11-2017:
The Wave traps required are supplied under R&U project and the same is to be commisioned at Sedam end for restoration of PLCC.
Also,M-II distance relays have already been supplied by GE Ltd.
KPTCL Mail dated 16.12.2017:
Carrier protection is to be restored. B/U OC and EF relay is to be replaced by M-II distance relay. Required materials like wave trap,
M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd.
Review Meeting dated 19.12.2017:
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.
KPTCLKPTCL was requested to explore the possibility of providing A/R feature to this
line and submit the remedial measures to the PCSC forum.
220kV Sedam-
Tandur line
40/IV/1
Annexure-II
Page 17 of 34
42/I/1 Complete outage of 220kV 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.
Mail received on 29-07-2015:
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 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.
KPTCL Mail dated 16.12.2017:
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.
Review Meeting dated 19.12.2017:
1 & 2) KPTCL informed that the works are under progress and are targeted to be completed by February, 2018.
Pending
42/I/2 (GD) Complete outage of 220 kV Ambewadi
substation of KPTCL
12-03-2015 at 7:51
hrs
Fault in 220kV Ambewadi-Nagjheri line-2 1. 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.
KPTCL Mail received on 29-07-2015:
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 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
Review Meeting dated 19.12.2017:
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.
Pending
48/I/2 Complete outage of 220kV Peenya
Substation in Karnataka
27-09-2015
at 4:23:17 hrs
All connected 220kV lines and transformers were taken
on 220kV North bus as South bus was under shut down
for conversion of strung bus to rigid bus and isolator
replacement under R&M works. Failure of HV side Y
phase CT of 150MVA Transformer-3 occurred at Peenya
Substation which resulted in operation of Differential and
HV REF protection. The failure of CT also resulted in a
220kV bus fault in North Bus.
KPTCL to revise distance relay settings at Nelamangala end for 220 kV
Nelamangala – Hebbal - Peenya line – 1 for the effective line length of 17 km.
These new settings can be appropriately reviewed as and when the tie-
arrangement at Hebbal is done away with.
KPTCL KPTCL mail received on 25-05-2016:
Presentl 220kV Nelamangala -Hoody (i.e. nelamangala-Peenya-Hebbal -Hoody line is made LIILO at Yelahanka sub station and
breaker at Peenya is kept open, necessary modification in distance relay settings adopted for new configuration.
KPTCL Mail Recieved dated 22-11-2017:
Since usage of this line as an Incoming line at Peenya is required for emrgency purposes, the settings of this line at Nelamangala end
will be reduced to 17KMs and as a special case, to cover the rest of the length of the line, Zone 2 timing will be reduced to 150 ms.
KPTCL Mail dated 16.12.2017:
The revised settings to be adpopted for this line considering reduced protected line length( 17KMs) is issued as a special case which
will be implemened and tested during scheduled outage.
Review Meeting dated 19.12.2017:
KPTCL informed that the revised setting would be implemented by December, 2017.
Pending
Annexure-II
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.
KPTCL Mail Recieved dated 22-11-2017:
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.
KPTCL Mail dated 16.12.2017:
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 reduced to 150mS. In view of the above, it is requested to drop the issue from this list.
Review Meeting dated 19.12.2017:
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
KPTCL Mail received dated 25-05-2016:
SEE, RTC, Bangalore to update the status
KPTCL Mail received dated 28-06-2016:
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.
KPTCL Mail received dated 25-04-2017:
GPS and accessories will be supplied during May 2017, expected to complete the work within a month after supply of materials.
KPTCL Mail Recieved dated 22-11-2017:
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 is a delay in dispatch of the same by M/s GE Ltd due to GST
issues, which is also addressed recently.
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
Review Meeting dated 19.12.2017:
1) & 2) KPTCL informed that the works are under progress, and are targeted to br completed by February, 2018.
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.
17-01-2016 at 18:53
hrs
Multiple tripping at 400kV Guttur SS 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.
PendingKPTCL
Annexure-II
Page 19 of 34
52/I/3 Complete outage of 220 kV Shimoga
substation
22-02-2016 at 15:03
hrs
220kV Bus Bar protection operated during failure of R
phase CT in DVG-2 line bay.
KPTCL to operate 220 kV Shimoga on multi-bus operation under normal
conditions, and put it on single-bus operation only under emergency conditions.
KPTCL KPTCL Mail received dated 25-04-2017:
Replacement of existing BBP by new BBP with 4 zone protection is being taken up under R&U.
KPTCL Mail Recieved dated 22-11-2017:
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.
KPTCL Mail dated 16.12.2017:
Due to operational constraints two/ multi bus operation is not being implemented.
Review Meeting dated 19.12.2017:
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.
Pending
53/I/1 Complete outage of 220kV Peenya
Substation of KPTCL
16-03-2016 at 11:39
Hrs
220kV Peenya-Nelamangala-3 tripped on B-E fault at
both ends. At the same time, 220kV Peenya-Nelamangala-
4 tripped on R-Y fault only at Nelamangala end, and was
in service from Peenya end. Due to tripping of these two
lines, 220kV Peenya-Nelamangala-2 tripped on
overcurrent protection.
KPTCL to furnish a report on the tripping of 220 kV Peenya-Nelamangala line-4
Nelamangala detailing the remedial measures taken including the settings
adopted for Z1B (Zone extension) and Power Swing Block.
KPTCL KPTCL Mail received dated 25-05-2016:
SEE, RTC, Bangalore to update the status
KPTCL Mail Recieved dated 22-11-2017:
Since usage of this line as an Incoming line at Peenya is required for emrgency purposes, the settings of this line at Nelamangala end
will be reduced to 17KMs and as a special case, to cover the rest of the length of the line, Zone 2 timing will be reduced to 150 ms.
KPTCL Mail dated 16.12.2017:
Considering it as special case, revised settings to be adpopted for this line considering reduced protected line length( 17KMs) is issued
which will be implemened and tested during next scheduled outage.
Review Meeting dated 19.12.2017:
KPTCL informed that the revised settings would be implemented by December, 2017.
Pending
57/II/1 Tripping of 220 kV Chikkodi-Mudshingi and
220 kV Chikkodi-Talandage lines
01-07-2016 at 03:03
hrs
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.
1.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.
KPTCL KPTCL Mail Recieved dated 22-11-2017:
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
KPTCL mail dated 16.12.2017:
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
Review Meeting dated 19.12.2017:
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
Pending
Annexure-II
Page 20 of 34
62/II/3 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)
09-01-2017
at 23:06 hrs
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
1. 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.
KPTCL KPTCL mail received dated 25.04.2017:
Numerical BBP is being provided under R&M works.
KPTCL Mail Recieved dated 22-11-2017:
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
KPTCL Mail dated 16.12.2017:
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
Review Meeting dated 19.12.2017:
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
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
KPTCL Mail Recieved dated 22-11-2017:
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.
KPTCL Mail dated 16.12.2017:
Numerical Bus Bar protection Scheme will be commissioned at Somanahally before end of December 2017
Pending
69/III/5 Tripping of 220 kV Sedam-Tandur line 10-10-2017 at 00:50
hrs &
10-10-2017 at 17:27
hrs
Tripped on Y-Phase to ground fault due to distance
protection operation. Auto reclosure could not be
validated from the submitted DR/EL.
KPTCL to enable and put A/R into service from Sedam end on 220 kV Sedam –
Tandur S/C line.
KPTCL Review Meeting dated 19.12.2017:
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.
Pending
Annexure-II
Page 21 of 34
49/I/3 Complete outage of 220kV 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
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:
2. Modifications to be carried in Nagzari SPS logic is submitted to SRLDC/SRPC for verification and approval
Status received vide KPCL mail dated 14.06.2017:
1. Will be reviewed in consultation with EE(RT), KPTCL, Hubli.
3. Both the lines are in charged condition.
KPTCL Mail Recieved dated 22-11-2017:
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
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
Review Meeting dated 19.12.2017:
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.
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.
Complete outage of 220 kV Nagjheri
power station and 220 kV Ambewadi
substation of KPTCL
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
KPCL/ KPTCL Pending
Annexure-II
Page 22 of 34
TANTRANSCO vide their mail dated 24.06.15 informed that different relays in Main-I & Main-II would be ensured at the earliest.
Mail recieved on 24-07-2015 ,19-02-2016 and 24-03-2016:
Different relays in Main-I & Main-II will be ensured.
Mail received on 27-04-2016:
TANTRANSCO: Not feasible in the existing SAS sub stations. Hence, exemption may be given for these sub stations.
Mail received on 20-05-2016 ,16-06-2016,25-07-2016 & 24-09-2016 :
As discussed in the 52nd PCSC meeting, Swapping of Relays between two stations is not feasible in the existing SAS sub stations.
Hence, exemption may be given for these sub stations.
Status received vide mails received on 10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 & 15.06.2017 & 04.08.2017:
Different make Relays will be ensured for Main-I & II relays at Alamathy end.
TANTRANSCO Mail received on 118-09-2017 & 31-10-2017
Different make Relays will be ensured for Main-I & II relays at Alamathy end.
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.
Tamil Nadu
25-01-2017 at 22:36
hrs
Tripping of running Units & 230kV feeders
at Tuticorin TPS of TANGEDCO
(Gen Loss: 640 MW)
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.
18-03-2016 at 14:40
hrs
Complete outage of 220kV Ambewadi
station of KPTCL and 220kV Nagjheri of
KPCL
53/I/3
29-03-2015 at 15:29
hrs
KPTCL Mail received dated 28-06-2016:
Modifications to be carried in Nagzari SPS logic is submitted to SRLDC/SRPC for verification and approval
Status received vide KPCL mail dated 14.06.2017:
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.
KPTCL Mail Recieved dated 22-11-2017:
2. Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be discussed and approved by the SRPC
forum. --- Pending
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
Review Meeting dated 19.12.2017:
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.
43/II/5
KPCL/ KPTCL
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
Review Meeting dated 19.12.2017:
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.
PendingTripping of 400kV
Alamathy-
SVChatram line-1&2
and 400/230kV ICT
at S.V.Chatram
TANTRANSCOTANTRANSCO was requested to swap the relays between two stations, so that
Main-1 and Main-2 will be of different make at each station.
Pending
Line-2 tripped on R-phase to earth fault.
Line autoreclosed at SVChatram end and failed to reclose
at Alamathy end. Bphase to earth fault in line-1. Line tried
for A/r but due to permanent fault line did not reclose.
ICT tripped on operation of over flux protection.
Failure 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.
TANGEDCO
Annexure-II
Page 23 of 34
TANTRANSCO Mail dated 12-12-2017:
Different make Relays will be ensured for Main-I & II relays at Alamathy end. Tender floated for relay procurement.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that the recommendation would be complied with by June, 2018.
TANTRANSCO Mail dated 25-01-2018:
Different make Relays will be ensured for Main-I & II relays at Alamathy end. Tender floated for relay procurement. Timeline: June-
2018.
29-03-2015 at 15:29
hrs
43/II/5 PendingTripping of 400kV
Alamathy-
SVChatram line-1&2
and 400/230kV ICT
at S.V.Chatram
TANTRANSCOTANTRANSCO was requested to swap the relays between two stations, so that
Main-1 and Main-2 will be of different make at each station.
Line-2 tripped on R-phase to earth fault.
Line autoreclosed at SVChatram end and failed to reclose
at Alamathy end. Bphase to earth fault in line-1. Line tried
for A/r but due to permanent fault line did not reclose.
ICT tripped on operation of over flux protection.
Annexure-II
Page 24 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.
Mail received on 20-02-2017:
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.
Status received vide mail dated 04.08.2017:
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 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.
Review Meeting dated 19.12.2017:
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.
Complete outage of 230kV Mywadi
station of TANTRANSCO
Disturbance in 220kV Tamilnadu system TANTRANSCO TANTRANSCO to take suitable measures like installing more stub-towers along
230 kV OK Mandapam – Myvady line to avoid excessive sag due to over-loading.
Complete outage of 230kV Palladam, 230 kV
Othakalmandapam S/s, 230 kV Coimbatore S/s, 230 kV
Thudialur and 230 kV Sadayapalayam S/s
05-09-2015 at 14:04
hrs
48/I/1
50/I/3 21-12-2015 at 6:28
hrs
PendingTANTRANSCO Mail received on 19-02-2016, 24-03-2016 and 27-04-2016:
230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar. Line restringing will be carried out along with the above
proposal.
Mail Received on 20-05-2016 ,16-06-2016,25-07-2016 & 24-09-2016:
230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar. Line restringing will be carried out along with the above
proposal.
Status received vide mails received on 10-11-2016 & 20.12.2016 & 12.04.2017 & 01.06.2017 & 15-06-2017 & 04.08.2017:
230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar. Line restringing will be carried out along with the above
proposal.
TANTRANSCO mail dated 18-09-2017 & 31-10-2017:
Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar. Line restringing will be carried out along with the above
proposal.
Status received vid email dated 12-12-2017:
Othakalmandapam - Myvadi feeder replacement of kundha conductor with Zebra and tower replacement work has been sanctioned.
Work will be taken up.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that 230 kV OK Mandapam - Myvady feeer was LILOed at Anaikadavu on 06.11.2017. Further replacement of
the existing Kundah condductor with Zebra has also been taken up, and is targeted to be completed by June, 2018.
TANTRANSCO mail dated 25-01-2018:
230kV Othakalmandapam - Myvadi feeder replacement of kundha conductor with Zebra and tower replacement work has been
sanctioned. Work will be taken up. Timeline: June-2018.TANTRANSCO PendingTANTRANSCO 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.
Busbar protection got operated for a fault in 230kV
Mywadi-Anaikadavu line
Annexure-II
Page 25 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.
55/I/1 (GD) Complete outage of 230 kV
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.
TANTRANSCO to take steps to provide double-bus operation at their 230 kV
Gummidipoondi SS.
TANTRANSCO 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..
Review Meeting dated 19.12.2017:
TANTRANSCO informed that Numerical BBP would be commissioned by March, 2018.
TANTRANSCO mail received on 25-01-2018:
Commissioning of Numerical Bus bar protection is under progress. Zone segregation will be ensured. Timeline: March-2018.
Pending
PendingTANTRANSCO 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.
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
19-01-2016
at 11:56 hrs
TANTRANSCO 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.
Status received vide mail dated 04.08.2017:
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.
Status received vide mail dated 18.09.2017:
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.
Status received vide mail dated 01.11.2017:
1 & 2) Contract awarded for providing third ICT & Bus modification works to accomodate bus coupler bay.
Numerical BBP relay was commissioned onj 29.08.2017.
Status received vid email dated 12-12-2017:
1 & 2) Numerical BBP relay was commissioned on 29.08.2017. Contract awarded for providing third ICT & Bus modification works to
accomodate bus coupler bay. --- Pending
3) --- Pending
Review Meeting dated 19.12.2017:
1&2) TANTRANSCO informed that multi-bus operation with Numerical BBP would be provided by June, 2018 for which the works are
under progress. --- Pending
3) TANTRANSCO informed that they would revert on providing Re-Trip feature fro LBB.
--- Pending
Complete outage of 230kV Madurai S/s
(Chekanaurani) of TANTRANSCO
51/I/1 (GD)
Annexure-II
Page 26 of 34
58 TANTRANSCO 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.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that the recommended works of providing different make Relays for Main-I & Main-II are targeted to be
completed by September, 2018.
TANTRANSCO mail received on 25-01-2018:
Different make Relays will be provided for Main-I & II relays at Sunguvarchatram end in a phased manner. Timeline: September-2018.
Pending
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.
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.
Multiple tripping at 230 kV Alamathy
Station
58/II/17
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]
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.
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
Review Meeting dated 19.12.2017:
2) TANTRANSCO informed that Numerical BBP would be provided by April, 2018
--- Pending
TANTRANSCO mail received on 25-01-2018:
1. Complied.
2. High impedance BBP relay will be replaced by Numerical relay. Timeline: April-2018.
TANTRANSCO Pending
Annexure-II
Page 27 of 34
64/1/4 Complete outage of North Chennai TPS
STG-1
26-03-2017
at 23:14hrs
Tripping of evacuating lines due to fault led to tripping of
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
Status received vid email dated 12-12-2017:
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
Review Meeting dated 19.12.2017:
2) TANTRANSCO informed that A/R would be implemented on all 230 kV lines emanating from NCTPS-I by June, 2018.
TANTRANSCO mail received on 25-01-2018:
1. Complied.
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. Timeline:June-2018.
Pending
Annexure-II
Page 28 of 34
Mail received on 31-07-2015:
1. Reducing the sensitivity of REF protection of Unit # 4, 5, 6 at Idukki PH: - Generation wing is planning to purchase new transformer
management relays with low impedance REF protection. Purchase procedures initiated. ---------Pending
2. The replacement/ repair of faulty breakers are under the consideration of Generation wing. Breakers will be replaced / repaired in a
phased manner. Unit #3 breaker was replaced with available breaker from the 220kV IDMD feeder. The 220kV CBs of unit #2 and unit
#3 will be replaced with in two months.
--- Pending
3. No abnormalities were noticed in the PLCC equipment at New Pallom station. It is kept under observation. --- Pending
Mail recieved on 30-10-2015:
1. Purchase procedures is still in progress --- Pending
2. Replaced. --- Completed.
3. PLCC equipment Tested and found OK --- Completed.
Mail recieved on 03-03-2016:
1. Even though repeated plans to have a joint inspection with M/s.ABB who is the OEM of the relay panel for replacing the relays with
numerical ones, the same could not become successful. Finally, the inspection has been fixed on 15.03.2016. It has been planned to
replace existing REF protection with low impedance ones after retrofitting the numerical ones of OEM.
--- Pending
KSEB Mail dated 25-05-2016:
1.Generation wing is planning ti provide low impedance REF protection by retrofitting numerical ABB make transformer management
relay in the existing panel.
--- Pending
KSEB Mail dated 12-12-2017:
1. On consultation with OEM, it was understood that the retrofitting of numerical ABB make transformer management relay in the
existing panel is not possible. Generation wing is planning to change the panels as part of RMU and is scheduled to start from
January'18 beginning. --- Pending
44/I/1 220 kV breaker of unit-3 at Idukki Power
house flashed and bus differential protection
acted. All Generators (6Nos.) along with all
220 kV feeders tripped during the incident.
28-04-2015 at 12:30
Hrs
Pending KSEB1. KSEB to reduce sensitivity of REF protection appropriately at Idukki PH.
2. KSEB to replace/ repair the faulty breaker.
3. KSEB to check the PLCC equipment at New Pallom and inform the remedial
measures taken to PCSC forum.
Complete outage of Idukki Hydro Power
Station (GD-1)
Kerala
Annexure-II
Page 29 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:
1. 110 kV bus bar protection is under progress
--- Pending
2. --- Completed
3. Redundacny of DC supply for both 110kV and 48v. Provided separate DC source (Redundant) for protection of 220kV feeders and
transformers. 48V DC redundacy is already there. --- Completed
4. Stand-alone 'event logger:- Numerical relays with time synchronization is available at 220kV substation Kalamassery and DRand El
is downloaded from these relays. KSEBl is not following Stand-alone event logger for substation. --- Completed
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
71/II/6 Multiple trippings at 220 kV Madakkathara 29-12-2017 at
14:56hrs
220 kV Madakkathara-Malaparamba feeder tripped at
Madakkathara end due to Y-phase to ground fault. LBB
protection trip acted and resulted in tripping of 220kV
Bus-1
KSEBL to furnish LBB scheme drawing showing various interconnections, and
confirm if resetting of LBB relay is implemented through self-resetting contacts of
the distance relay.
KSEB Yet to be informed Pending
55/II/9 Tripping of HVDC Gazuwaka pole-2 19-05-2016 at 11:41
hrs
Pole tripped on operation of differential current
protection of east side of Pole-2
PGCIL (SR-I) to take up the issue of differential protection operation of converter
transformer on low voltage fluctuations with their OEM, and submit a detailed
report on it.
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017 :
Issue taken up with OEM and still under study. Till now the OEM could not explain the reason for the said operation of protection. All
data has been shared with OEM and further perused to identify the cause of the same and remedial action.
Pending
56/II/11 Tripping of HVDC GazuwakaPole-2 19-06-2016 at 5:20
Hrs
HVDC Pole-2 got tripped on operation of Bus differential
protection
PGCIL (SR-I) to get the tripping of HVDC Pole-2 tripping on Win-Bus differential
protection thoroughly investigated for correctness of operation, and submit a
report thereon.
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:
Issue taken up with OEM and still under study. Till now the OEM could not explain the reason for the said operation of protection. All
data has been shared with OEM and further perused to identify the cause of the same and remedial action.
Pending
65/II/15 Tripping of HVDC Gazuwaka Pole-1&2 25-05-2017 at 09:45
hrs
HVDC pole-1 got tripped due to operation of South filter
inter zone protection and HVDC pole-2 got tripped due to
operation of differential protection
PGCIL (SR-I) to furnish detailed report on the events that led to tripping of HVDC
Poles – 1 & 2 including remedial measures taken to PCSC forum. Further, the
OEM report w.r.t. tripping of HVDC Pole-2 shall also be furnished.
PGCIL (SR-I) PGCIL (SR-I) Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:
Issue taken up with OEM and still under study. Till now the OEM could not explain the reason for the said operation of protection for
Pole 2 . All data has been shared with OEM and further perused to identify the cause of the same and remedial action thereof if any.
Pending
67/II/5 Tripping of HVDC Bhadravati Pole-1 07-07-2017 at 10:59
hrs
Pole-1 tripped due to PC1 INTERNAL MINOR ALARM
WEST - ALARM. Pole protection extended trip without
any protection operation
PGCIL (SR-I) in coordination with PGCIL (WR-I) to take up the issue with its OEM,
and furnish the reasons for Pole-1 tripping along with remedial measures taken.
PGCIL (SR-I) Review Meeting dated 19.12.2017:
PGCIL (SR-I) was asked to take up the sissue with PGCIL (WR-I) and furnish action taken report by 10.01.2018.
Pending
67/II/6 Tripping of HVDC Bhadravati Pole-1 09-07-2017 at 14:43
hrs
Pole-1 tripped due to PC1 INTERNAL MINOR ALARM
WEST - ALARM. Pole protection extended trip without
any protection operation
PGCIL (SR-I) in coordination with PGCIL (WR-I) to take up the issue with its OEM,
and furnish the reasons for Pole-1 tripping along with remedial measures taken.
PGCIL (SR-I) Review Meeting dated 19.12.2017:
PGCIL (SR-I) was asked to take up the sissue with PGCIL (WR-I) and furnish action taken report by 10.01.2018.
Pending
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
PGCIL (SR-I) & PGCIL (SR-II)
Complete outage of 220 kV Kalamassery
Substation
58/I/1 (GD) Triggering incident was conductor snapping in 110 kV
Kalamassery- Kaloor feeder
23-08-2016
at 11:20 hrs
KSEB
Annexure-II
Page 30 of 34
68/II/8 Tripping of HVDC Gazuwaka Pole-1 & Pole-
2
28-09-2017 at 17:30
hrs
HVDC Poles – 1 & 2 got tripped due to Auxilliary supply
failure
PGCIL (SR-I) to study the solution proposed by ABB in their paper on “Mitigation
of Ferro-resonance in Line Commutated HVDC Converter Interconnected with
Series Compensated Overhead Line Transmission System” presented in 2016 IEEE
Electrical Power and Energy Conference (EPEC) for implementation feasibility,
and furnish an Action Taken Report w.r.t. the same.
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017:
Ferro resonance is being observed at GWK for any disturbance at Jepore end. ABB have suggested to keep FSC in service at Jeypore
end when powerflow is more than 250MW per line. At low powers FSC is generating resonanting frequencies & causing ferro
resonance.
If SRPC advises, the FSC shall be kept out for powerflow below 500 MW as a mitigation measure to avoid ferro-resonance.
Review Meeting dated 19.12.2017:
PGCIL (SR-I) was requested to refer the solution propsoed to their Corporate for implementation feasibility. It was also made clear to
PGCIL (SR-I) that any issue relating to revision of FSC settings can be directly taken up with NLDC.
Pending
68/II/12 Tripping of 400 kV NPS – Nellore-PG D/C
line
08-10-2017
at 18:58 hrs
Lines tripped during a fault on 400 kV Nellore-PG –
Vijayawada line-2
1. For the 400 kV Nellore-PG – Vijayawada line, PGCIL (SR-I) to investigate the
reasons for 3-ph tripping of Main-CB upon detection of the fault without trying
for A/R and operation of Stub/ Tee protection at the time of Tie-CB A/R attempt
at Vijayawada end during instant trippings, and furnish remedial measures taken
to address the issues involved.
2. PGCIL (SR-I) to test the recently commissioned CSD’s at their 400 kV Nellore-
PG SS at the earliest and ensure their correct operation.
3. PGCIL (SR-I) to configure DR’s and EL’s of Distance Protection Relays at Nellore-
PG with suitable LEGENDs for indicating operation of type of protections (like
Zone-1, Zone-2, Zone-3, DEFR, OVR-I, OVR-II, etc.).
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:
1. --- Pending.
2. Due to CSD contractor problem CB Y-pole reclosed & defective contactors replaced & wiring problem in CSD rectified on next day --
- Completed.
3. NPS end DR & EL configured as suggested. --- Completed.
Pending
24.11.2017
at 13:06 hrs
24.11.2017
at 14:26 hrs
70/III/4 Tripping of 400 kV Ramagundam-
Chandrapur line-2
15-11-2017 at 13:17
hrs
R-phase to earth fault had occurred in line. line auto-
reclosed at Ramagundam end
PGCIL (SR-I) to furnish an action taken report on the reasons for A/R non-
operation at Chandrapur end including remedial measures taken to PCSC forum.
PGCIL (SR-I) Yet to be Informed Pending
71/II/3 Tripping of HVDC Gazuwaka Pole-2 08-12-2017 at 19:29
hrs
Pole-2 got tripped due to failure of Valve Cooling system
VFD (Variable Freq Drive control)
PGCIL (SR-I) to furnish reasons for VFD-1 failure in the instant tripping, and share
OEM’s observations w.r.t. the same, along with remedial measures proposed.
PGCIL(SR-I) Yet to be Informed Pending
70/II/6 Tripping of 400 kV Nellore-PG - NPS line-2 Line tripped due to mal-operation of differential relay at
NPS end and was in service from Nellore.
For the subject line, PGCIL (SR-I) to configure DR’s & EL’s of Line Differential
Relays for recording all requisite protection operations at their Nellore PS.
PGCIL (SR-I) Yet to be Informed Pending
Annexure-II
Page 31 of 34
Pending
Others
NPCIL (MAPS)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.
54/I/1 02-04-2016 at 17:08
hrs
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.
Complete outage of 230 kV S.P.Koil
Station of TANTRANSCO
Annexure-II
Page 32 of 34
62/III/2 Tripping of 400 kV Kaiga-Guttur line-1 06-02-2017
at 05:01 hrs
B-phase to earth fault. Line did not auto-reclose at Kaiga
end.
1. KGS to properly configure all relays DR’s time scale for a post-triggering period
of 2 sec to capture events such as complete A/R operation.
2. KGS to ensure time-synchronization of all protection relays with GPS in their
400 kV switchyard.
NPCIL (KGS) Status received vide mail dated 29.11.2017 & Review Meeting dated 19.12.2017:
1. All 400kv transmisisonlines relays DR time scale for a post-triggering period of 2 sec is implemented. ----Completed
2.Time-synchronization for all lines protection relays (M1 &M2) with GPS in their 400 kV switchyard is being implemeneted. Scheme
design is in process. ECD-April-2018 ---- Pending
Pending
67/II/7 Tripping of 400kV JSWEL - Guttur line 09-07-2017 at 18:02
hrs &
24-07-2017 at 02:05
hrs
Line tripped on operation of Over Voltage, Stage-1
protection at Guttur end and Direct Trip was received at
JSWEL.
JSWEL to configure their end DR’s and EL’s for DT receipt/ send event for 400 kV
JSWEL – Guttur line.
JSWEL Status received vide mail dated 14.12.2017
JSWEL will configure DR’s & event lists for DT send/ Receipt for 400kV JSWEL-Guttur Line during next opportunity / outage in
concurrence with Guttur end.
Review Meeting dated 19.12.2017:
It was noted that no JSWEL representative had come to the meeting. The issue was discussed, and it was decided that JSWEL would
complete the recommended work by the end of December, 2017.
Pending
68/II/11 Tripping of 400 kV
K V KOTA - HNPCL lines – 1 & 2
29-09-2017 at 22:36
hrs
Line-1 tripped on R-E Zone-1 fault, and the Line-2 tripped
on Direct Trip receipt at KV Kota end
1. HNPCL to ensure time sync of all of their protection relays with GPS, and to
configure corresponding DR’s for post triggering time of 2 sec.HNPCL to configure
DEF operation only when Distance relay does not sense the fault.
2.HNPCL to ensure healthiness of A/R scheme implemented on all 400 kV lines at
their station.
3.HNPCL to provide priority A/R scheme for 400 kV Tie-CB’s with s suitable dead-
time of say 2 sec.
4.HNPCL to revise PDR timing as 1.5 sec till implementation of A/R for Tie-CB’s
after which it shall be further revised to 2.5 sec.
5.HNPCL to implement following OVR-I gradings for the 400 kV lines emanating
from their station:
Kalpaka Line-1 7.35 A 111%, 10 sec
Kalpaka Line-2 7.35 D 110%, 8 sec
KV Kota Line-1 246 B 111%, 9 sec
KV Kota Line-2 246 G 109%, 6 sec
HNPCL HNPCL Mail dated 11.01.2018:
1. Time synchronization of protection relays and BCU's with GPS completed. As per APTRANSCO recommendations DEF has been
switched off in line protection relays.
--- Pending
2. --- Pending
3. Line Tie CBs Priority closing has been implemented for all the lines. --- Pending
4. --- Pending
5. --- Completed
Pending
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 blocked condition as
long as Distance Protection is active, and becomes active only when distance
protection does not pickup.
TPCIL Yet to be informed Pending
Annexure-II
Page 33 of 34
69/II/9 Tripping of 400 kV Neyvelli TS2 – Pugalur
and 400 kV Neyvelli TS2 (exp) – Pugalur
line
10-10-2017 at 23:54
hrs
Protection at NLCTS-2 & NLCTS-2 Exp has sensed as R-Y-E
fault and given a 3 phase trip. At Pugalur end protection
has sensed fault as Y-N and B-N fault in 400kV Neyveli
TS2-Pugalur line & 400kV Neyveli TS2 EXP-Pugalur line
respectively. Breaker at Pugalur got tripped due to Direct
Trip receipt.
1.For the tripping of 400 kV NLC TS2 – Pugalur line, NLCIL to investigate the
reasons for sending of DT to Pugalur end, and furnish an action taken report
including remedial action taken and setting right various LEGEND issues in DR &
EL of protection relays to PCSC forum.
2. For the tripping of 400 kV NLC TS2Exp – Pugalur line, NLCIL to investigate the
reasons for 3-ph tripping (detection of the fault as Y-B-E) of the line from NLC
TS2Exp end including verifying pertinent settings of P437 relay (reference may be
made to explanation given by TPCIL in GD - I.1/ GD - I.2), and furnish an action
taken report including remedial action taken and setting right various LEGEND
issues in DR & EL of protection relays to PCSC forum.
NLCIL NLCIL Mail dated 18.01.2018:
1. Shut down was taken on 400kV Neyveli TS-II to Pugalur feeder on 18-01-18 to check the
end-to-end communication for DT/ permissive & other signals by testing at both the ends and to check the healthiness of the PLCC
system components.
The system was thoroughly checked and the missing loops in the relay circuit (Carrier
send in Main1 relay and Carrier receive in Main2 relay) were provided.
Omicron test kit was used to create single phase faults and Auto reclose of breaker was
checked for both Main1 & Main2 relays. Direct trip command was initiated from both
Main1 & Main 2 relays for over voltage .Carrier send and received at both Pugalur and
Neyveli Ts-II end was found to be proper for both permissive and direct trip commands.
Similarly permissive and direct trip commands were simulated from Pugalur end and the
same was found to be normal at both Pugalur and Neyveli TS-II end.
The level measurement was measured and found to be normal ---- Completed
2. --- Pending.
Pending
71/III/1 Tripping of 400 kV HNPCL- KV Kota line-2 26-12-2017 at 12:34
hrs
R-phase to earth fault had occurred in line. Breakers at
HNPCL got tripped due to auto-reclose lockout and auto-
reclose was successful at KV Kota end.
HNPCL to furnish a report detailing the reasons for A/R non-operation in the
instant tripping, and remedial measures taken to set right them.
HNPCL Yet to be informed Pending
Annexure-II
Page 34 of 34
Sl.No. Element Name Outage
date/time
Revival
date/time
Reason for Outage Sender/ Receiver Remedial Measures/ Actions taken
1
400 Kv NTPL - TTRNPS 25-10-2017/12:01:00 TRIPPED ON R-B-N FAULT NTPL/ PGCIL (SR-II) PGCIL (SR-II):
Line Auto Reclosed and tripped due to persisiting
Fault. It was gathered that problem at NTPL Switch
Yard.
PGCIL(SR-II):
Line Auto Reclosed and tripped due to persisiting
Fault. It was gathered that problem at NTPL Switch
Yard (In B-ph Gas Insulated Bus Duct IR value observed
to be zero and Sf 6 leakage observed at NTPL GIS.)
NTPL:
2
400kV VTPS -MALKARAM 05-12-2017/10:45:00 05-12-2017/11:51:00 DT RECEIVED APGENCO/ TSTRANSCO TSTRANSCO: Tripped at Both ends. Tripped on Direct
Trip received indications at Malkaram end. Other end
tripped on Over Voltage.
3
400KV/220KV DICHPALLY-ICT-3 08-12-2017/10:23:00 08-12-2017/14:58:00 To take IR values TSTRANSCO TSTRANSCO:
Line Clearance was taken on ICT-3 and IR testing of
windings, CTs Tan delta testing was done as part of
periodical maintenance.
4
400KV-MALKARAM-VTPS_IV-1 27-12-2017/14:39:00 27-12-2017/15:42:00 MAL-OPERATION TSTRANSCO/ APGENCO TSTRANSCO:
Line is in service at Malkaram end.
APGENCO:
5 400KV-LKPPL_STG2-VIJAYAWADA-2 06-01-2018/10:53:00 swapping. LANCO/ PGCIL (SR-I) To-be-discussed
6
400KV-MAMIDAPALLI-DINDI-2 09-01-2018/11:29:00 09-01-2018/11:52:00 RELAY MALOPERATION TSTRANSCO TSTRANSCO:
Direct trip was sent from Dindi to Mamidipally SS
while maintenance officials were checking the panels
at Dindi end.
Instructions were given to be careful while checking
the panels of in service feeders.
7
400KV-BTPS-YTPS-1 11-01-2018/06:17:00 11-01-2018/07:11:00 TRIPPED ON B-N FAULT KPCL KPCL:
line tripped on operation of Zone-1 Protection due to
C-Phase to ground fault. Line had auto reclosed
immediately but auto reclose locked out due to
persistent fault.
8
400KV/220KV VEMAGIRI_AP-ICT-2 14-01-2018/06:58:00 14-01-2018/08:32:00 TRIPPED DUE TO B-N LINE APTRANSCO APTRANSCO:
Back up O/L and E/L protection shall be tested for
ensuring healthiness of the relays.
9400KV/220KV HOODY-ICT-3 14-01-2018/17:42:00 14-01-2018/18:34:00 OVER FLUX PROTECTION KPTCL To-be-discussed
10400KV-KTPS_VI-KHAMMAM-2 14-01-2018/12:14:00 14-01-2018/12:47:00 MAL-OPERATION TSGENCO/ PGCIL (SR-I) To-be-discussed
11400KV-KOLAR_AC-HOODY-2 14-01-2018/17:42:00 15-01-2018/02:32:00 LIGHTENING ARESTER PGCIL (SR-II)/ KPTCL To-be-discussed
Pending Remedial Measures/ Actions taken
for the Critical Tripping Incidents (as on 26.02.2018)
Annexure-III
Page 1 of 3
12400 KV CHITTOOR-SRIPERUMBADUR 15-01-2018/01:02:00 TRIPPED ON B-N FAULT APTRANSCO/ PGCIL (SR-II) APTRANSCO:
Retrofitting of relays done recently.
13400KV-HOODY-NELAMANGALA-1 400KV AC L
ARRESTER
21-01-2018/18:35:00 R-PHASE LIGHTNING
NELAMANGALA END
KPTCL To-be-discussed
14400KV/230KV NEYVELI_TS_II-ICT-1 25-01-2018/21:36:00 TRIPPED ON SPARK IN
BUSHING
NLCIL To-be-discussed
15220KV-AMBEWADI-PONDA-2 220KV 01-02-2018/10:41:00 01-02-2018/11:07:00 TRIPPED ON A PHASE TO
GND FAULT
KPTCL/GED To-be-discussed
16400KV/220KV GAJWEL-ICT-1 01-02-2018/16:13:00 01-02-2018/16:49:00 230 KV BUS BAR
PROTECTION OPERATED
TSTRANSCO To-be-discussed
17400KV-GAJWEL-RAMAGUNDAM-1 05-02-2018/01:13:00 D/T RECEIVED AT GAJWEL
END
TSTRANSCO/ NTPC-
RAMAGUNDAM
To-be-discussed
18 400KV-KOCHI-TRICHUR-2 05-02-2018/18:01:00 05-02-2018/18:33:00 TRIPPED ON B-N FAULT PGCIL(SR-II) To-be-discussed
19
400KV-MAMIDAPALLI-KHAMMAM-1 07-02-2018/15:26:00 07-02-2018/16:11:00 TRIPPED ON B-N FAULT TSTRANSCO/ PGCIL (SR-I) PGCIL(SR-1):
Line tripped on B-N fault. Fault distance: 75.42kms, FC:
4.180kA from KMM end. Distance: 173.2kms, FC:
1.464kA from Mpally end. Main CB & Tie CB A/R
attempted 1st time & successful at KMM end. For fault
during reclaim time, line tripped. Line belongs to
TSTRANSCO.
TSTRANSCO:
20
220KV-SULURPET-GUMMIDIPOONDI-1 07-02-2018/13:50:00 07-02-2018/14:20:00 TRIPPED ON R-N FAULT APTRANSCO/ TANTRANSCO TANTRANSCO: Feeder was charged at Gummidipoondi
end at 14:20 hrs. on 07.02.2018.
21
220KV-SULURPET-GUMMIDIPOONDI-1 07-02-2018/14:30:00 07-02-2018/14:40:00 POLE DESCRIPENCY APTRANSCO/ TANTRANSCO TANTRANSCO: Feeder was charged at Gummidipoondi
end at 14:20 hrs. on 07.02.2018.
22
400KV-NELAMANGALA-HASSAN-1 12-02-2018/16:02:00 TRIPPED ON R-N FAULT KPTCL/ PGCIL (SR-II) To-be-discussed
23
400KV/220KV PAVAGADA-ICT-2 12-02-2018/15:09:00 12-02-2018/18:06:00 HAND TRIPPED AFTER IDLE
CHARGE
PGCIL (SR-II) To-be-discussed
24
400KV-NELAMANGALA-HASSAN-1 14-02-2018/14:22:00 TRIPPED ON B-N FAULT KPTCL/ PGCIL (SR-II) To-be-discussed
25
400KV-SRISAILAM_LEFT_BANK-DINDI-1 14-02-2018/07:08:00 TRIPPED ON Y-N FAULT TSGENCO/ TSTRANSCO To-be-discussed
26
400KV/220KV DINDI-ICT-1 14-02-2018/15:48:00 14-02-2018/19:56:00 Winding Resistance
measurement
TSTRANSCO To-be-discussed
27
400KV-GOOTY-NPS-2 15-02-2018/16:30:00 15-02-2018/16:45:00 TRIPPED ON LBB OPERATION PGCIL (SR-I) To-be-discussed
28
400KV-VALLUR-ALAMATHY-1 16-02-2018/17:31:00 16-02-2018/19:30:00 Bph LA Failure at Almaty end NTECL/ TANTRANSCO To-be-discussed
29
400KV-NELAMANGALA-HASSAN-1 17-02-2018/15:21:00 B PHASE TO GROUND KPTCL/ PGCIL (SR-II) To-be-discussed
30
400KV-KTPS_VII-KHAMMAM-1 17-02-2018/13:04:00 17-02-2018/13:27:00 Tripped at KTPS end on B-N
Fault
TSGENCO/ PGCIL (SR-I) To-be-discussed
31
220KV-TIRUNELVELI-EDAMON-1 220KV 19-02-2018/14:58:00 19-02-2018/18:58:00 LA FAILURE AT EDAMON
END
PGCIL (SR-I)/ KSEBL To-be-discussed
Annexure-III
Page 2 of 3
32
400KV-KAIGA-GUTTUR-1 400KV 19-02-2018/17:30:00 19-02-2018/19:44:00 TO ATTEND FAULT IN LINE 2 NPCIL (KGS)/ KPTCL To-be-discussed
33
220KV-YERRAANDAHALLI-HOSUR_TN-1
220KV
19-02-2018/01:41:00 19-02-2018/02:53:00 BUSBAR PROTECTION
OPERATED AT HOSUR END
KPTCL/ TANTRANSCO To-be-discussed
34
400KV/220KV DINDI-ICT-1 19-02-2018/14:45:00 19-02-2018/17:25:00 OIL LEAKAGE TSTRANSCO To-be-discussed
35
400KV-NAGARJUNASAGAR_PG-
MEHBOOBNAGAR-1 400KV
20-02-2018/00:28:00 20-02-2018/01:05:00 AUTO RE-CLOSURE
OPERATIONAL
PGCIL (SR-I)/ TSTRANSCO To-be-discussed
36
400KV-MUNIRABAD-RTPS-1 20-02-2018/10:17:00 20-02-2018/11:26:00 BREAKER LOCKOUT PGCIL (SR-I) To-be-discussed
37
400KV-NELAMANGALA-TALGUPPA-1 21-02-2018/16:04:00 21-02-2018/18:16:00 TRIPPED ON R-N FAULT KPTCL To-be-discussed
38
400KV-NELLORE_PG-VIJAYAWADA-1 22-02-2018/01:37:00 22-02-2018/03:13:00 TRIPPED ON R-Y FAULT PGCIL (SR-I) To-be-discussed
39
400KV-KAIGA-GUTTUR-2 22-02-2018/17:23:00 22-02-2018/18:42:00 DT RECEIVED AT KAIGA END NPCIL (KGS)/ KPTCL To-be-discussed
40
400KV-GOOTY-NARNOOR-1 23-02-2018/07:20:00 23-02-2018/08:46:00 TRIPPED ON Y-N FAULT PGCIL (SR-I)/ APTRANSCO To-be-discussed
41
400KV-GHANAPUR-MAMIDAPALLI-1 23-02-2018/12:23:00 LOAD MANAGEMENT PGCIL (SR-II)/ TSTRANSCO To-be-discussed
42
400KV-KTPS_VI-KTPS_VII-1 24-02-2018/18:11:00 25-02-2018/02:05:00 H/T due to heavy spark near
Bus2
TSTRANSCO To-be-discussed
43
220KV-AMBEWADI-PONDA-1 24-02-2018/13:51:00 24-02-2018/14:12:00 DISTANCE PROTECTION KPTCL/ GED To-be-discussed
Annexure-III
Page 3 of 3
TRANSMISSION CORPORATION OF TELANGANA LIMITED
From To The Chief Engineer The Member Secretary, Power Systems SRPC,
TSTRANSCO, 29, Race Course Road Vidyuth Soudha, Hyderabad. Bangalore-560 009. E-Mail: [email protected]
Lr.No.CE/PS/SEPS/SP2/211/Relays’C’/Vol- 208/D.No.33/18, Dt:14-02-2018
Sir, Sub:- TSTRANSCO- Implementation of SPS on 220kV HIAL –
Sivarampally, 220kV Mamidipally – Sivarampally and 220kV
Shankarpally – Gachibowli feeders-1&2 –Submission of SPS scheme proposals at 220kV Sivarampally and 220kV Gachibowli substations to SRPC –Approval –Requested-Reg.
*** The following 220 kV feeders are getting overloaded during (N-1)
contingency.
1. 220kV HIAL – Sivarampally 2. 220kV Mamidipally – Sivarampally 3. 220kV Shankarpally – Gachibowli feeders-1
4. 220kV Shankarpally – Gachibowli feeders-2
In view of safety of grid and to avoid cascade tripping of above lines during contingency, TSTRANSCO has proposed for implementation of SPS scheme at 220kV Sivarampally and 220kV Gachibowli substations.
The SPS scheme is formulated duly conducting the load flow studies
with an anticipated Telangana grid demand of 10,000MW and with the
identified loads and elements to be tripped when the line loadings are exceeding the limits as mentioned below at 220kV Sivarampally and 220kV
Gachibowli substations and are enclosed in ANNEXURE-I and ANNEXURE-II respectively to bring the line loadings below the emergency loading limits.
The sequence of events and load flows on various elements in and around 220kV Sivarampally and 220kV Gachibowli substations due to
operation of SPS scheme during (N-1) contingencies are tabulated in the enclosed ANNEXURE-III.
The details of proposed SPS schemes are as follows.
Whenever the load on subject feeders exceeds the 97%, 98% and 100%
of emergency thermal loading limit of Zebra conductor (i.e., 616A as per CEA planning criteria Jan 2013) the identified loads/elements shall trip in STAGE-I, STAGE-II and STAGE-III with respective stage wise time delays duly utilizing
the following.
Contd::2::
Annexure-IV
Page 1 of 9
::2::
At 220kV Sivarampally substation:
a. Available spare PS class CT secondary core on 220kV HIAL and
220kV Mamidipally feeders.
b. Stand-alone Three stage Directional Over Current relay on each feeder.
c. Tripping of following elements/loads.
i. In Stage-I: 132kV MD Pally-1&2 and 132kV Erragadda feeders with time delay of 4 sec.
ii. In Stage-II: 132kV Asifnagar feeder with time delay of 8 sec.
iii. In Stage-III: Circuit breakers of 220kV Gachibowli feeders-1&2
with time delay of 12sec.
At 220kV Gachibowli substation:
a. Available spare PS class CT secondary core on 220kV Shankarpally
feeders-1&2. b. Stand-alone Three stage Directional Over Current relay on each
feeder.
c. Tripping of following elements/loads.
i. In Stage-I: 50MVA PTR (de-paralleled) or 33kV feeders of its equivalent load with time delay of 2sec.
ii. In Stage-II: 132kV RC Puram feeders-1&2 with time delay of 6sec.
iii. In Stage-III: Circuit breakers of 220kV Erragadda, 220kV Miyapur and 220kV Shapoornagar feeders-2&3 with time delay of 10 sec.
In this regard, it is requested to arrange necessary approval for
implementing the above SPS schemes.
Encl: Annexure-I,II&III
Yours faithfully,
CHIEF ENGINEEER
POWER SYSTEMS Copy to:
The Chief Engineer/SLDC/TSTRANSCO/Vidyut Soudha/Hyderabad. The Divisional Engineer/Tech. to the Director (Projects & Grid Operation)/ TSTRANSCO.
The Divisional Engineer/Tech. to the Director (Transmission)/TSTRANSCO.
Annexure-IV
Page 2 of 9
ANNEXURE-I
33
HIAL
Mamidipally
Gachibowli
Stage-1
I>600A
Stage-1
I>600A
OR
Stage-1
Tripping
TD=4Sec
Stage-2
I>608A
Stage-2
I>608A
OR
Stage-2
Tripping
TD=8Sec
Stage-3
I>616A
Stage-3
I>616A
OR
Stage-3
TrippingTD=12Sec
STAGE-3 TRIPPING
Tripping of 2Nos CBs (CB3
& CB4) of 220kV Gachibowli
feeders-1&2 at 220kV
Sivarampally SS
STAGE-1 TRIPPING
Tripping of 3Nos CBs (CB5,
CB6 & CB7) of 132kV
Erragadda & 132kV MD
Pally DC lines
STAGE-2 TRIPPING
Tripping of 1No CB (CB8)
of 132kV Asifnagar at
220kV Sivarampally SS
Sivarampally
CT1
CT2
CB1
CB2
CB3
CB4
MDPally-1
MDPally-2
Erragadda
CB5
CB6
CB7
AsifnagarCB8
SPS Arrangement at 220kv Sivarampally SS
At 220kV Level: 600A = 229MVA = 206MW
At 220kV Level: 608A = 232MVA = 209MW
At 220kV Level: 616A = 235MVA = 211MW
Note: As per CEA Planning Criteria Jan 2013, the thermal loading limit of Zebra conductor is 560A at conductor temperature of 750
C and ambient temperature of 450 C. Emergency loading limit of conductor is 110% of normal thermal limit. Therefore, the
emergency loading limit of Zebra conductor is considered as 1.10 x 560 = 616A or 235MVA or 211MW (at 0.9 p.f).
TD=4Sec
TD=8Sec
TD=12Sec
Annexure-IV
Page 3 of 9
ANNEXURE-II
Shankarpally
Gachibowli
Stage-1
I>600A
Stage-1
I>600A
ORStage-1
Tripping
TD=2Sec
Stage-2
I>608A
Stage-2
I>608A
ORStage-2
Tripping
TD=6Sec
Stage-3
I>616A
Stage-3
I>616A
ORStage-3
TrippingTD=10Sec
STAGE-3 TRIPPING
Tripping of 4Nos CBs (CB5,
CB6, CB7 & CB8) at 220kV
Gachibowli SS
STAGE-1 TRIPPING
Tripping of “Group-A” loads
(i.e., 1No deparalled
50MVA PTR or equivalent
33kV feeder loads) at
220kV Gachibowli SS
STAGE-2 TRIPPING
Tripping of “Group-B” loads
(i.e. 132kV RC Puram DC
line) of 220kV Gachibowli
SS
CB1
CB2
CB5
CB6
132kV
Loads
SPS Scheme at 220kv Gachibowli SS
Ckt-2
CB7
CB8
Ckt-3
33
Sivarampally
CT1
CT2
CB3
CB4
Erragadda
Miyapur
Shapoornagar
33kV Loads
At 220kV Level: 600A = 229MVA = 206MW
At 220kV Level: 608A = 232MVA = 209MW
At 220kV Level: 616A = 235MVA = 211MW
Note: As per CEA Planning Criteria Jan 2013, the thermal loading limit of Zebra conductor is 560A at conductor temperature of 750
C and ambient temperature of 450 C. Emergency loading limit of conductor is 110% of normal thermal limit. Therefore, the
emergency loading limit of Zebra conductor is considered as 1.10 x 560 = 616A or 235MVA or 211MW (at 0.9 p.f).
TD=2Sec
TD=6Sec
TD=10Sec
Annexure-IV
Page 4 of 9
ANNEXURE-III(1/4)
SPS Operation at 220KV Sivarampally and Gachibowli Substations
Sequence of Operations on Overload
Time
Delay
in Sec
Event Pick-Up at
Sivarampally
Pick-Up at
Gachibowly
HIA
L -
Siv
ara
mp
all
y
Mam
idip
all
y -
Siv
ara
mp
all
y
Siv
ara
mp
all
y -
Gach
ibow
li-1
Siv
ara
mp
all
y -
Gach
ibow
li-2
Sh
an
karp
all
y -
Gach
ibow
li-1
Sh
an
karp
all
y -
Gach
ibow
li-2
Gach
ibow
li -
Err
agad
da
Gach
ibow
li -
Miy
ap
ur
Malk
ara
m-
SH
PN
-1
Malk
ara
m-
SH
PN
-2
SH
PN
-
Err
agad
da
SH
PN
-Miy
ap
ur
Gach
ibow
li -
Sh
ap
urn
agar-
2
Gach
ibow
li -
Sh
ap
urn
agar-
3
0 Base Case 219 201 49 49 180 224 49 32 153 153 88 43 -13 -13
All the loads are in MVA with an anticipated load demand of 10,000MW
SSx(y)
SS = SPS at
SVP
SG = SPS at
GCB
x = Stage No
y = After y
seconds
Annexure-IV
Page 5 of 9
ANNEXURE-III(2/4)
SPS Operation at 220KV Sivarampally and Gachibowli Substations
Sequence of Operations on Tripping of Shapoornagar-Malkaram
Time
Delay
in
Sec
Event Pick-Up at
Sivarampally
Pick-Up at
Gachibowly
HIA
L -
Siv
ara
mp
all
y
Mam
idip
all
y -
Siv
ara
mp
all
y
Siv
ara
mp
all
y -
Gach
ibow
li-1
Siv
ara
mp
all
y -
Gach
ibow
li-2
Sh
an
karp
all
y -
Gach
ibow
li-1
Sh
an
karp
all
y -
Gach
ibow
li-2
Gach
ibow
li -
Err
agad
da
Gach
ibow
li -
Miy
ap
ur
Malk
ara
m-
SH
PN
-1
Malk
ara
m-
SH
PN
-2
SH
PN
-
Err
agad
da
SH
PN
-Miy
ap
ur
Gach
ibow
li -
Sh
ap
urn
agar-
2
Gach
ibow
li -
Sh
ap
urn
agar-
3
0 Base Case 219 201 49 49 180 224 49 32 153 153 88 43 -13 -13
1 SPR-MLK-1
Tripped SS1(0) SG1(0),SG2(0),SG3(0) 231 212 59 59 193 240 53 46 0 241 72 27 15 15
2
SS1(1) SG1(1),SG2(1),SG3(1) 231 212 59 59 193 240 53 46 0 241 72 27 15 15
3 STG-1 at GCB SS1(2) SG1(2),SG2(2),SG3(2) 225 207 54 54 187 232 56 50 0 233 71 24 17 17
4 SG2(3) 225 207 54 54 187 232 56 50 0 233 71 24 17 17
5 STG-2 at GCB SG2(4) 207 190 38 38 167 208 63 60 0 207 68 16 25 25
6
7
8
9
Annexure-IV
Page 6 of 9
ANNEXURE-III(3/4)
SPS Operation at 220KV Sivarampally and Gachibowli Substations
Sequence of Operations on HIAL - Sivarampally
Time
Delay
in
Sec
Event Pick-Up at
Sivarampally
Pick-Up at
Gachibowly
HIA
L -
Siv
ara
mp
all
y
Mam
idip
all
y -
Siv
ara
mp
all
y
Siv
ara
mp
all
y -
Gach
ibow
li-1
Siv
ara
mp
all
y -
Gach
ibow
li-2
Sh
an
karp
all
y -
Gach
ibow
li-1
Sh
an
karp
all
y -
Gach
ibow
li-2
Gach
ibow
li -
Err
agad
da
Gach
ibow
li -
Miy
ap
ur
Malk
ara
m-
SH
PN
-1
Malk
ara
m-
SH
PN
-2
SH
PN
-
Err
agad
da
SH
PN
-Miy
ap
ur
Gach
ibow
li -
Sh
ap
urn
agar-
2
Gach
ibow
li -
Sh
ap
urn
agar-
3
0 Base Case 219 201 49 49 180 224 49 32 153 153 88 43 -13 -13
1 HIAL-SVP
Tripped SS1(0),SS2(0),SS3(0) SG1(0),SG2(0),SG3(0) 0 336 14 14 201 249 42 22 168 168 91 53 -16 -16
2
SS1(1),SS2(1),SS3(1) SG1(1),SG2(1),SG3(1) 0 336 14 14 201 249 42 22 168 168 91 53 -16 -16
3 STG-1 at GCB SS1(2),SS2(2),SS3(2) SG1(2),SG2(2),SG3(2) 0 328 12 12 194 242 45 25 162 162 90 50 -14 -14
4 SS1(3),SS2(3),SS3(3) SG2(3),SG3(3) 0 328 12 12 194 242 45 25 162 162 90 50 -14 -14
5 STG-1 at SVP SS1(4),SS2(4),SS3(4) SG2(4),SG3(4) 0 306 19 19 190 236 47 29 157 157 89 46 -13 -13
6 SS2(5),SS3(5) SG2(5),SG3(5) 0 306 19 19 190 236 47 29 157 157 89 46 -13 -13
7 STG-2 at GCB SS2(6),SS3(6) SG2(6),SG3(6) 0 281 -12 -12 170 211 55 41 139 139 84 34 14 14
8 SS2(7),SS3(7) 0 281 -12 -12 170 211 55 41 139 139 84 34 14 14
9 STG-2 at SVP SS2(8),SS3(8) 0 247 -24 -24 162 202 59 47 132 132 82 29 17 17
10 SS3(9) 0 247 -24 -24 162 202 59 47 132 132 82 29 17 17
11 SS3(10) 0 247 -24 -24 162 202 59 47 132 132 82 29 17 17
12 SS3(11) 0 247 -24 -24 162 202 59 47 132 132 82 29 17 17
13 STG-3 at SVP SS3(13) 0 206 0 0 173 215 56 41 138 138 84 33 12 12
Annexure-IV
Page 7 of 9
ANNEXURE-III(4/4)
SPS Operation at 220KV Sivarampally and Gachibowli Substations
Sequence of Operations on Tripping of Shanakarpally - Gachibowli
Time
Delay
in
Sec
Event Pick-Up at
Sivarampally
Pick-Up at
Gachibowly
HIA
L -
Siv
ara
mp
all
y
Mam
idip
all
y -
Siv
ara
mp
all
y
Siv
ara
mp
all
y -
Gach
ibow
li-1
Siv
ara
mp
all
y -
Gach
ibow
li-2
Sh
an
karp
all
y -
Gach
ibow
li-1
Sh
an
karp
all
y -
Gach
ibow
li-2
Gach
ibow
li -
Err
agad
da
Gach
ibow
li -
Miy
ap
ur
Malk
ara
m-
SH
PN
-1
Malk
ara
m-
SH
PN
-2
SH
PN
-
Err
agad
da
SH
PN
-Miy
ap
ur
Gach
ibow
li -
Sh
ap
urn
agar-
2
Gach
ibow
li -
Sh
ap
urn
agar-
3
0 Base Case 219 201 49 49 180 224 49 32 153 153 88 43 -13 -13
1 SNK-GCB-1
Tripped SS1(0),SS2(0),SS3(0) SG1(0),SG2(0),SG3(0) 243 223 71 71 0 317 41 20 171 171 92 56 -18 -18
2
SS1(1),SS2(1),SS3(1) SG1(1),SG2(1),SG3(1) 243 223 71 71 0 317 41 20 171 171 92 56 -18 -18
3 STG-1 at GCB SS1(2),SS2(2),SS3(2) SG1(2),SG2(2),SG3(2) 237 218 66 66 0 307 43 24 165 165 91 52 -16 -16
4 SS1(3),SS2(3),SS3(3) SG2(3),SG3(3) 237 218 66 66 0 307 43 24 165 165 91 52 -16 -16
5 STG-1 at SVP SS1(4),SS2(4),SS3(4) SG2(4),SG3(4) 222 204 74 74 0 301 45 26 161 161 90 49 -15 -15
6 SG2(5),SG3(5) 222 204 74 74 0 301 45 26 161 161 90 49 -15 -15
7 STG-2 at GCB SG2(6),SG3(6) 203 187 56 56 0 269 54 39 143 143 85 37 14 14
8 SG3(7) 203 187 56 56 0 269 54 39 143 143 85 37 14 14
9 SG3(8) 203 187 56 56 0 269 54 39 143 143 85 37 14 14
10 SG3(9) 203 187 56 56 0 269 54 39 143 143 85 37 14 14
11 STG-3 at GCB SG3(10) 173 160 28 28 0 224 0 0 180 180 126 70 0 0
12
13
Annexure-IV
Page 8 of 9
Annexure-IV
Page 9 of 9