SOUTHERN REGIONAL POWER COMMITTEE - Karnataka · SOUTHERN REGIONAL POWER COMMITTEE ... following...

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Minutes of the 41st

Meeting of Protection Coordination Sub- Committee

(PCSC – 41) of SRPC held on 26.02.2015

1. Introduction

The 41st meeting of Protection Coordination Sub-Committee (PCSC) was held on 26

th

February, 2015 in the Conference Hall of Southern Regional Power Committee, Bangalore.

The list of participants is enclosed at Annexure-I.

Shri S.R.Bhat, Member Secretary (MS), SRPC welcomed the Members and Participants to the

meeting and briefed them on the following points:

A Special Meeting was held on 19th

February 2015 at IL&FS to analyze cause for the Grid

Incidents that occurred on the NLC 1 Exp – IL&FS – Trichy 400 kV S/C line during

January-February, 2015. M/s IL&FS and M/s NLC had been recommended to carry out

certain system-tests and modifications relating to Auto –Reclose operation, PLCC

operation, Over- Voltage relay settings, DEF settings, etc. to prevent recurrence of such

trippings. PCSC forum appreciated the cooperation extended by PGCIL, NLC and IL&FS

in resolution of the protection issues in that corridor. The Minutes of the Meeting are

enclosed at Annexure-II.

With reference to Petition No. 374 filed by TANTRANSCO before Hon’ble CERC seeking

time extension for Phase-I and Phase-II activities of Protection Audit Recommendations, all

Southern Region Constituents had been directed to file status of implementation of protection

system in their respective States to the Commission by 31st March 2015.

Remedial measures/ action taken in respect of tripping incidents, some as old as August-

2014 were still awaited. He requested the Constituents to furnish the measures/ action

taken to SRPC at the earliest.

On account of paucity of time in monthly meetings of OCC, state-wise meetings had been

conducted to address the specific issues. In this regard, a Meeting was held with M/s

KPTCL to address various issues including installation of U/V relays. Similarly, a Meeting

had been held with representatives of Andhra Pradesh and Telangana to sort out various

issues including segregation of feeders between Andhra Pradesh and Telangana for the SPS

schemes.

A presentation on Protection Management System software would be delivered by M/s

PRDC later in the meeting. He requested the Constituents to use the opportunity to seek

any clarifications on this matter

22. Confirmation of the Minutes of the 40th

PCSC meeting held on 29-01-2015

SE (Protection), SRPC stated that Minutes of the 40th meeting of PCSC were circulated vide

SRPC letter No. SRPC/SE-III/ PCSC-40/2015/1000-1031 dated 16.02.2015. In this regard,

following observations were received from TANTRANSCO and NTPC, Ramagundam.

(i) TANTRANSCO Observations: SE (Design, P&C), TANTRANSCO stated that in

Annexure-II to the Minutes, the tripping incident relating to 220 kV Sedam –Tandur line at

Sl. No. IV(1), the corresponding Constituent was not TANTRANSCO, and as such the

recommendation may be suitably modified. Accordingly, the recommendation given

therein was modified as follows:

“KPTCL was requested to explore the possibility of providing

A/R feature to this line and submit the remedial measures to the PCSC forum.”

(ii) NTPC, Ramagundam Observations: AGM (EM), NTPC, Ramagundam stated that in the

40th

meeting of PCSC, the recommendation of Power System Analysis Group – 11

(PSAG-11) relating to implementation of Auto-Reclosure (A/R) on Ramagundam –

Chandrapur 400 kV D/C line was discussed, but not reflected in the Minutes at Sl. No. 13

(i). Accordingly, the deliberations of the PCSC forum as given under on the issue referred

may be treated as being included at Sl. No. 13(i) of the Minutes:

“With respect to the recommendation of PSAG-11 regarding implementation of

Auto-Reclosure (A/R) on Ramagundam – Chandrapur 400 kV D/C line, KSEB

Representative suggested that 3-Phase A/R may be got implemented at both ends.

He explained that 1-Phase A/R is basically provided to clear a transient L-G fault

on a faulty phase without jeopardizing the reliability of the grid by making

available the other two phases for service. However, in the instant case with 3-

Phase A/R at Bhadrawati, no useful purpose will be served with 1-phase A/R at

Ramagundam, as all the 3-Phases will be in or out together. Moreover, due to the

capacitive coupling that exists between the out-of-service phase and the other two

in-service phases, the time required to bring the out-of-service Phase into service

will be significantly higher compared to that obtained with 3-Phase A/R in place at

both ends.”

The PCSC forum noted KSEB’s observations and recommended 3-Phase A/R at

NTPC, Ramagundam end.”

With this, the Minutes of the 40th

meeting of the PCSC were confirmed.

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

mal- operation, Auto-Reclose non-operation

The trippings due to GD’s, GI’s, PLCC mal-operation and Auto–Reclosure failure/non-

operation that had occurred during the period, January – February, 2015 were discussed in the

Meeting. The deliberations and recommendations of the PCSC-forum are enclosed at

Annexure–III.

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

under forced outage

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

remedial measures/ action yet to be taken were discussed in the Meeting. Constituents were

requested to kindly furnish the remedial measures/ action taken in time so as to forward the

same to Central Electricity Authority. The updated list of the same as on 12.03.2015 is

enclosed at Annexure-IV.

5. Status of pending PCSC recommendations

The status of implementation of pending PCSC recommendations were discussed in the

meeting. The constituents were requested to kindly submit the status of their compliance latest

by 20.03.15. The updated status of the same as on 13.03.2015 is enclosed at Annexure-V.

6. Status of Protection System Analysis Group (PSAG) Recommendations

The status of implementation of recommendations of the following PSAG meetings was

discussed in the Meeting.

PSAG -10 Grid Disturbances at Kadra, Kodasalli,

Kaiga during Sept – Oct, 2014

KPCL, NPCIL

PSAG -12 Grid Disturbances at Upper Sileru HPS

during Nov – Dec, 2014

APGENCO

The compliance reports as furnished by the KPCL, APGENCO are enclosed at Annexure-VI,

Annexure-VII respectively.

Status of the recommendations of PSAG-11 regarding operational aspects of HVDC,

Bhadrawati could not be discussed as the same was not furnished. PGCIL (SR-I & II) were

requested to kindly coordinate with their WR-counterparts in this regard, and furnish the

compliance of PSAG-11 recommendations to SRPC at the earliest.

7. Certificate for Healthiness of Batteries

As per the MoP/ CEA direction given in pursuant to recommendations of the Enquiry

Committee (NEW grid disturbance on 30th

& 31st July, 2012), RPC’s are required to obtain

from their respective Constituents 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 are requested to submit the certificate on

healthiness of batteries on monthly basis (i.e. on 7th

day of the month) to SRPC.

The sought status for the month of January, 2015 has not been received from the following

SR-Constituents:

TSGENCO (Hydro), TANGEDCO, PGCIL (SR-I), NPCIL (MAPS), NTECL, JSWEL

& GMR

8. Suggestions for providing settings for High set of Earth fault relay on HV side of

Generator Transformer (with Star connection on HV side and Delta connection on LV

side)

KSEB Representative presented his views on providing settings for High set of Earth fault

relay on HV side of Generator Transformer (GT) [with Star connection on HV side and

Delta connection on LV side]. During deliberations, the following salient points were noted:

1. Delta –Star transformer configuration makes transformer impedance as its zero

sequence impedance. There will not be any effect on High-Set setting from whatever

that may be connected to delta side (whether it is open, generator connected, load

connected)

2. For star –star power transformers, zero sequence impedance will be affected by the

connected load impedance on the other side of the transformer in series with

transformer impedance.

3. In the case of power transformers with delta connected tertiary winding, the effect will

be sum of those provided above (vide items 1 and 2). The zero sequence impedance will

be shunted by the impedance of tertiary winding.

4. It was noted that high-set unit of E/F relay of generator transformer trips for feeder

ground faults. This is due to the flow of zero sequence currents through transformer

neutral. Time of high-set unit of E/F relay (IDMT) is to be properly coordinated with

distance protection and directional earth fault relay on the feeders.

5. The setting of high set of earth fault relay shall be such that it will not mal-operate for

close-in external fault even at highest fault level condition. However, this relay shall

operate for in-zone fault, i.e., for faults inside phase side CTs and transformer neutral.

This will be possible only when recommended high set setting is provided in the earth

fault protection in residual connection of Transformer phase side CTs. Therefore, high

set for earth fault protection shall only be provided on residual connected earth fault

protection from phase side CTs. The high set unit shall not be provided in the earth fault

protection connected to neutral CT.

6. As shown in the write-up (ref: Agenda, PCSC-41), the total fault current contributions

through Generator Transformer neutral will be highest when all elements, viz., GT and

Generator and the System to which they are connected are all in service. Further, to

account for the difficulties in getting the exact sequence network picture (system

configuration), DC Offsets in CTs, X/R in systems, etc., the setting for High-set can be

arrived at by multiplying the above maximum fault current with a suitable factor, say

1.3. However, as the protection area of high-set unit of earth fault relay is between CTs

on HV side of GT and (including) transformer HV winding, which is normally covered

by Restricted Earth Fault protection and Transformer differential protection (these are

more sensitive than high set unit earth fault relay), the High-Set may be provided with 5

cycles delay (100 msec).

9. Dynamic study data submission

All SLDCs were requested to direct the embedded IPPs connected at 220 kV and above

voltage level to submit completed dynamic study format to SRPC, Secretariat. Constituents

were requested to submit the Dynamic study data at the earliest.

10. Network configuration changes

As per the information furnished by the SR-Constituents to the OCC forum in the 104th

Meeting held on 10.02.2015 (Minutes circulated on 02.03.2015), it is observed that no

network configuration changes (additions/ deletions/ modifications of transmission

elements) took place during the month of January, 2015.

11. New formats for reporting failure of substation equipment / towers of transmission

lines at 220kV and above

It is intimated that CEA has revised formats for reporting of failures of substation

equipment and failure of transmission line towers at 220 kV & above. The new formats are

enclosed at Annexure-VIII. These formats for reporting the failures are also available in

CEA's website (www.cea.nic.in).

12. SPS for Neelamangala – Peenya lines

In the 40th meeting of PCSC, the SPS for Peenya-Nelamangala was discussed; wherein

KPTCL informed that the existing SPS had been designed to handle load relief of around

50 MW for three lines of Nelamagala- Peenya corridor. However presently there are 4

lines, each loaded to around 150-200 MW. In view of the changed scenario, KPTCL

proposed that they would review the existing SPS so as to provide a load relief of up to

200 MW for each line whenever any line carries more than 200 MW. The finalized SPS

scheme as furnished by KPTCL is enclosed at Annexure-IX. Members may kindly note.

13. Compliance of Hon’ble CERC Orders

13.1 Petition No. 146/MP/2013 with I.A. 36/2013: Order dated 20.02.2014

Compliance of Regulations 5.2 (r) of the Grid Code: Issue regarding non-

furnishing of FIR / Trip Analysis Report, EL, DR, etc. was also

highlighted. It is pointed out that the above reports are to be submitted /

uploaded on SRLDC web application within 24 hours as mandated under

IEGC / CEA Regulations.

Implementation of Phase-I and Phase-II of Protection Audit

Recommendations: All the constituents are requested to submit the updated

status of the compliance (those who have not completed recommendations

mentioned in the Phase I and Phase II) to SRPC Secretariat at the earliest.

The following constituents are to submit the updated status of filing of

petition/affidavit to SRPC Secretariat at the earliest: APTRANSCO.

Compliance of Regulations 5.2 (e) & 5.2 (l) of the Grid Code and Regulation

3(1)(e) of CEA Grid Standards: The constituents are requested to strictly

comply with these provisions by ensuring standard protections systems having

the reliability, selectivity, speed and sensitivity to isolate the faulty equipment

and protect all components from any type of faults, within the specified fault

clearance time and providing protection coordination

Ensuring proper maintenance of transmission lines and adopting best O&M

practices: The constituents are requested to conduct line patrolling regularly

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).

(http://www.srpc.kar.nic.in/website/2014/operation/patrolling.pdf).

13.2 Petition No. 167/Suo- Motu/2012: Order dated 22.02.2014

Constituents are requested to follow approved protection philosophy

ISTS licensees are requested to submit details of updated distance protection relay

setting of all inter-regional lines with POSOCO & RPCs.

All SLDCs are requested to install/activate sound recording system in their control

rooms within three months from the date of issue of this order.

The constituents are requested to submit the progress of implementation to

SRPC and SRLDC as specified in the Hon'ble CERC Order.

13.3 Petition No. 263/MP/2012: Order dated 19.12.2013

Constituents are requested to implement the quantum of relief by AUFR and df/dt

relays by identifying additional feeders and keep them functional within one month

of issuing this order.

SLDCs are also requested to map these relays on their respective SCADA

system within three months of issuance of this order.

The constituents are requested to submit the progress of implementation to

SRPC and SRLDC as specified in the Hon'ble CERC Order.

14. Date & Venue of the next Meeting

It is informed that the 42nd

PCSC meeting will be held on 26.03.2015 (Thursday) at 10.30

hrs at SRPC Secretariat, Bangalore.

X ------------------------------------------ X ------------------------------------------ X

http://www.srpc.kar.nic.in/website/2014/operation/patrolling.pdf

Annexure-I

Annexure-I

Annexure-I

Annexure-I

Annexure-I

Annexure-II

Record Notes of Discussions of Special Meeting held at IL&FS on 19-02-2015

to discuss the Grid Incidents that occurred in the months of January-

February, 2015

SRPC Special committee had visited IL&FS power station on 19-02-2015 for investigating the

tripping of lines pertaining to IL&FS. The list of participants are enclosed at Annexure-I.

Four tripping pertaining to lines connected to IL&FS had occurred during January and February

2015. It was observed that lines had tripped once due to several reasons cited below:

R-phase to earth fault

Over voltage tripping

PLCC mal-operation

Manual error.

Following were the major observations and recommendations of the committee:

1. After LILO works, Main-2 distance relay settings were not revised at NLC Expansion

line for 400kV NLC Expansion -IL&FS line. The settings were asked to be revised.

2. Auto-reclose scheme is to be tested at both for 400kV NLC Expansion -IL&FS as line

did not auto reclose during an R-phase to earth fault in line. NLC Expansion needs to

review distance protection scheme in view of three phase tripping with receipt of carrier

signal by 1st Week of April 2015.

3. End to End PLCC testing was required to be carried out for 400kV NLC Expansion -

IL&FS line. PLCC Ch-1 is unhealthy for this line. It was proposed to replace both the old

PLCC panels. POWERGRID and NLC Expansion had agreed to replace the old PLCC

panels. In this Regard NLC Expansion was requested to approach GM (O& M) SR-II for

up gradation of PLCC.

4. Drop off to Pick up ratio of over voltage relay was asked to be tested at IL&FS.

5. Minor changes in time delay of DEF setting was proposed i.e, an additional time delay of

1.1 sec was to be added so that DEF operates after Zone-3 time. Settings to be revised at

IL&FS end.

6. Remaining protection settings were found to be in-order at IL&FS. The D.R & E.L were

functional and time synchronized with GPS

7. IL&FS representative was asked to upload the FIR, D.R and E.L on SRLDC trip web

portal within 24hrs of occurrence of the incident.

8. IL&FS representative had informed that necessary precautions have been taken to avoid

tripping of lines due to human error.

9. IL&FS was asked to carry out patrolling in LILO Portion.

Annexure-II

Annexure-II

1

Grid Occurrences

I. GRID DISTURBANCES (GD):

1 Complete outage at 220kV Kadra power Station of KPCL (GD-1)

(i) Date and Time of Event 16-02-2015 at 12:56 hrs

(ii) Location 220 kV Kadra Hydro Power Station

(iii) Plant and/or Equipment

directly involved

All connected elements (Generating plants and

220kV feeders) at Kadra Station.

(iv) Reported Disturbance /

Fault

Triggering incident was B-phase to earth fault

in 220kV Kadra-Kodasalli line. This line

tripped from Kodasalli end only in Zone-1.

220kV Kaiga-Kadra tripped in Zone-3 from

Kaiga end. Tripping of evacuating lines caused

bus shut down at Kadra hydro station.

(v) Generation/Load Loss Nil

(vii) Category GD-1

SLD:

Deliberations:

KPCL:

1. A fault (B phase to earth) occurred on 220kV Kadra-Kodasalli line. As a result,

At Kodasalli end, Kadra line tripped on DPR, Zone-1, and B-N fault.

At Kadra end, Distance protection provided on Main-1 relay (PZ-1000)

picked up in Zone-1, but DC fuse was blown out prior to tripping and the

relay could not operate. The back-up relay of English Electric make, though

wired, is yet to be commissioned.

At Kaiga end, Kadra line tripped on DPR, Zone-3, and B-N fault.

At the time of tripping, there was no generation at Kadra

Kadra Kodasalli

Kaiga

G1

G2

G3

G1

G2

G3

Karwar Nagjheri PH

S/D hand trip Z1 (B)

trip

Z3 (B) trip

Annexure-III

2

As Karwar station is a radial feeder, the power flow is zero.

2. At Kadra HPS, there are two battery banks (1 & 2) , but the supply to protection

system is availed from one bank only. The second bank, though available, is not kept

in service. The switching between two battery banks is being carried out manually.

3. Corrective Action:

The Fuse was replaced at Kadra station.

SRLDC:

At Kaiga end, Zone-3 operation of Kadra – Kaiga line is in order.

Fault current observed for 652 ms in B-phase of 220kV Kaiga-Kadra line at Kaiga

end.

Trip Coils 1 & 2 (TC-1, TC-2) of the circuit breakers shall get supply from different

sources (i.e. bank-1, and bank-2).

From 27.02.2015 onwards, Kadra-Kodasalli line shall be kept open and Kadra

generation shall be stalled and continue to remain so till the issues are addressed and

completed.

KSEB:

As the fuse was blown out, there could be some short circuit that had to be located

and cleared.

KPTCL:

On many CBs, there is an arrangement of an NC coil dropping out in case of failure

of one battery bank and starting the other battery bank.

Nowadays an arrangement is being made to have independent DC sources from

DCDB itself.

By the first week of March, 2015, RT team from KPTCL would be ready to test the

relays at KPTCL stations.

DC supply cables, breaker control cables, and trip coils have to be checked.

SRPC:

KPCL is requested to expedite the implementation of the recommendations of earlier

PCSC meetings, protection audit, and PSAG meetings.

A meeting is proposed to be convened in the first week of March, 2015 with KPCL

higher management to discuss the status of their pending protection issues.

Recommendations:

KPCL to make functional the Main2 (EPAC) relay with the help of KPTCL at the

earliest.

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.

KPCL to ensure supply for Main-1& Main-2 protections, Trip Coils (TC1, TC2)

from separate battery banks.

Annexure-III

3

2 Complete outage at 220kV Bahoor Substation of Pondicherry (GD-1)


(ii) Location 230 kV Bahoor Substation


directly involved

All connected elements at Bahoor Substation.


Fault

Bus fault occurred in 110kV bus at 230/110kV

Bahoor substation due to failure of Y-phase main

bus strain insulator. 220kV lines connected to

Bahoor (viz., Bahoor- NLC TPS II and Bahoor –

Pondy) tripped from remote end on operation of

back up protection.

(v) Load Loss 75 MW

(vii) Category GD-1

Deliberations:

From Trip Reports, the following were noted:

There was a fault at 110 kV bus at Bahour station. ICT back up protections did not

operate.

E/F (Y-B) relay operated (0.861 sec) at NLC – 2 on NLC-2 – Bahour 230 kV line.

Distance relay operated in Zone-3 (Y-B) (1.435 sec) at PGCIL Pondicherry substation

on Pondicherry – Bahour 230 kV line.

Annexure-III

4

SLD:

Puducherry Electricity Department (PED):

There was a flash over on the strain insulator of the 110 kV bus bar conductors, due to

which the conductors got snapped and fell down on the ground causing bush fire.

The fault location was on 110 kV bus side which is inside the differential protection

zone of the 230/110 kV transformer. However, ICT back-up protection did not operate.

Bus bar protection was not provided for 110 kV bus at Bahour 230/110 kV sub-station.

Remote end feeders tripped on back-up protection (Pondy – Bahour tripped on

operation of Zone-3; NLC 2 – Bahoor tripped on operation of back-up E/F relay)

PT fuse alarm came on 220 kV side due to disturbance.

Relay testing is generally carried out by TANTRANSCO.

SRLDC:

It appeared that the substation was charged after the fault without carrying out any

fault analysis.

As the fault was inside the transformer differential zone, differential protection should

230 kV

Bahour Inox Eripakkam

Auto-1 Auto-2

NLC 2 Pondicherry (PGCIL)

Bahour (PED)

110 kV

Z3 (Y-B) - trip E/F (Y-B) - trip

hand trip

Y-phase jumper snapped;

fell on the ground;

resulted in bush fire

Annexure-III

5

have operated.

The fault was persisting for 1.5 seconds, but neither differential protection nor other

back up relays operated.

Relay settings for ICTs have to be tested and installed by 27.02.2015, otherwise

transformer would be kept opened till the testing is completed and relays are made

functional.

KSEB:

As there are two ICT’s on the same 110kV Bus, there might be a chance for sensing

only half of the total earth fault current (since it is a parallel connection) by each ICT.

The current sensed might have been below the Earth fault setting of the ICTs, so the

relay might not have got operated.

Need to check the current value and also the time settings of the Earth fault relay of

ICTs.

TANTRANSCO:

On invitation, relay testing would be done at Bahour station on chargeable basis.

Recommendations:

PED to investigate the cause of non-operation of ICT’s protection system (differential

protection, back-up protection) and review the relay settings suitably at Bahour S/S.

PGCIL to check the settings of distance relay and back-up relays for correctness of

operation at Pondy S/S.

3 Complete outage of Nagjheri Hydro power station of KPCL (GD-1)


(ii) Location Nagjheri Hydro Power station


directly involved

All connected elements at Nagjheri Hydro

Power station.


Fault

During de-synchronization of Unit-3, the Y-

pole of the CB did not open (was locked-out).

This caused LBB protection to operate

resulting in tripping of the Bus and all

connected 220kV lines and running units at

Nagjheri power station.

(v) Generation/ Load Loss 550MW

(vii) Category GD-1

Annexure-III

6

SLD:

Deliberations:

KPCL:

While desynchronizing unit#3, the circuit breaker got stuck up and did not open.

This caused LBB protection to operate resulting in tripping of the Bus and all

connected 220kV lines and running units at Nagjheri power station.

LBB and BBP are provided in separate relays at Nagjeri power house.

As the disturbance recorder is very old, obtaining report is difficult.

SRLDC:

LBB protection might have got trigger from low forward power relay

Report on tripping is not yet submitted even after one week of the incident.

Usually, during afternoon and night hours, the power house is under shutdown;

during these hours, the protection system should have been checked for ascertaining

the cause of station outage and got rectified.

KSEB:

Low forward power, negative sequence values, and operator emergency button

would initiate LBB relay.

Master trip relay for bus differential would also trip for LBB.

SRPC:

KPCL is requested to expedite the implementation of the recommendations of earlier

PCSC meetings, protection audit, PSAG meetings.

A meeting is proposed to be convened in the first week of March, 2015 with KPCL

higher management to discuss the status of their pending protection issues.

Recommendations:

KPCL to investigate the cause of Y-pole breaker lock-out of Unit-3, and take suitable

remedial measures within a week’s time

KPCL to furnish what caused LBB initiation and furnish LBB Scheme details to

PCSC forum

KPCL to furnish detailed tripping report (with DR & EL) of the incident

Nagjheri (KPCL)

L)

Bus bar protection

trip

GT

150 MW

Bidnal Hubli Ambewadi

Kodasalli

alli

G

G

G4 G3

G2

G1

Annexure-III

7

4 Complete outage at 220kV Sedam Substation of KPTCL (GD-1)

(i) Date and Time of Event 27-01-2015 at 8.00 hrs

(ii) Location 220 kV Sedam Substation


directly involved

All connected elements at Sedam Substation.


Fault

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.

(v) Generation/ Load Loss Nil

(vii) Category GD-1

SLD:

Deliberations:

KPTCL:

R-Phase to ground fault occurred on 220kV Sedam-Shahapur line. As a result,

At Shahapur end, the line tripped on distance protection, Zone-1, RN, 1.26km.

At Sedam end, distance relay operated in Zone-2. But due to problem in the

breaker, it did not trip.

220 kV

Tandur

(TSTRANSCO)

Sedam (KPTCL)

Raichur Shahapur Humnabad

handtrip

Z1 (Rn) Z2

Z2 Line did not trip due

to problem in CB

Annexure-III

8

220kV Sedam-RTPS lines tripped at RTPS end on distance protection, Zone-2.

Due to tripping of source lines at RTPS and Shahapur end, 220 kV bus became

dead at Sedam Sub Station.

220kV Sedam-Tandur interstate line was hand-tripped.

Remedial Measures:

Problem in Shahapur line breaker was attended to at Sedam substation before

restoration of the line.

The resistive reaches of distance relays at Sedam substation have been revised.

Directions have been given to check the distance relay and back up relays of

Shahapur line at Sedam Substation.

220kV line distance relay settings at RTPS end have been reviewed.

Bus bar protection and LBB protection are not provided at Sedam; measures have

been taken to provide these protection schemes at Sedam and the same is in

tendering stage.

Similar kind of fault occurred on 15.02.2015 and it was noted that there was again a

problem with line CB. So, line CB was taken out of service and the bus coupler CB

is now used as line CB.

SRLDC:

It appeared that there is no A/R operation on Sedam – Tandur line, which is an

interstate line.

For interstate lines A/R shall be made available as envisaged in CEA’s Grid

Standards. SRLDC would be issuing notice to constituents shortly in this regard.

Further, A/R feature is to be provided for intrastate lines of the Constituents also and

SLDC shall monitor and ensure this.

Recommendations & Follow-up:

KPCL to provide Bus bar and LBB protections for 220 kV bus at Sedam S/s.

KPCL to implement A/R feature on 220 kV Sedam-Tandur inter-state line.

II. GRID INCIDENTS (GI):

Sr.

No.

Details of Events Date and Time Reason Category

1 Tripping of 400kV

Vijayawada-Nellore line 1

22-01-2015 at

11:39 hrs

line tripped on operation of TEED

protection at Vijayawada end and

direct trip was received at Nellore end

GI-2

Deliberations:

Vijayawada – Nellore-1 400 kV line tripped on operation of TEED- 1, B-ph protection at

Vijayawada end, even though there was no fault; DT was sent to Nellore end due to which

Nellore end CBs got opened.

Annexure-III

9

SRLDC:

TEED protection should operate only when the line isolator was in OPEN condition.

Non-operation of stub protection for non-fault unbalance condition to be ensured.

Noted with concern that the line was charged without analysing the fault.

Charging code for line won’t be given to constituents unless fault was analysed, relays involved

were tested and cause was removed.

PGCIL:

There was no fault in the line; it was a typical case of mal-operation of TEED protection.

As there was a man power shortage (and many stations were unmanned), analysis could not be

submitted immediately.

SRPC:

It appeared that there was a time difference of 3 seconds in EL’s of Vijayawada and Nellore.

It appeared that DTS from Vijayawada was not seen as DTS in Nellore EL.

Recommendations:

PGCIL shall review the TEED protection at Vijayawada end with their OEM group and

submit action taken report to PCSC forum.

2 Tripping of 400kV

Srisailam-

Mamidapalli-2

line and 400kV

Srisailam-

Satenapalli-1 line

23-01-2015 at

16:10 hrs

Bus-2 at Srisailam became dead while

converting Srisailam generator to

condenser mode. Direct trip was received

at Mamidapalli and Satenapalli end.

GI-2

Deliberations:

During the changeover of Srisailam Generator to Condenser mode, BBP for Bus-2 operated at

Srisailam LLB (Left Bank); Mamidapalli and Sattenapalli got tripped due to DT receipt from

Srisailam LLB.

SRLDC:

Reason for LBB operation shall be submitted by TSGENCO.

SRPC:

It was noted that no representative from TSGENCO attended the meeting.

As the event logger output was without millisecond time stamp, sequence of events could not

be ascertained within a second.

TSTRANSCO:

The DR at Mamidipally was being retrofitted, as such the details could not be furnished.

Reasons for BBP operation at Srisailam LLB would be obtained from TSGENCO, and

furnished to PCSC forum.

Recommendations:

TSGENCO to furnish the reasons for BBP operation at Srisailam LLB and the remedial

action taken to PCSC forum.

Annexure-III

10

3 Tripping of 400kV

NLC-1 EXP-

IL&FS line and

400kV IL&FS -

Trichy line

24-01-2015 on

13:15 hrs

400kV NLC-1 EXP- IL&FS line tripped

on a R-phase to earth fault. Line did not

auto-reclose. 400kV IL&FS - Trichy line

tripped at Trichy due to Direct trip receive

from IF&FS.

GI-2

Deliberations:

Tripping of 400kV NLC-1 EXP --- IL&FS line: R-phase to Ground fault occurred near IL&FS.

The line tripped at both ends in Zone-1 due to A/R operation. But at NLC-1 Exp, instead of 1-

Phase trip, three phase trip happened, due to which the line did not auto reclose successfully.

Tripping of 400kV IL&FS --- Trichy line: The voltage at IL&FS shot up resulting in operation

of OVR at IL&FS; Trichy end tripped due to DT receipt from IL&FS.

SRPC committee had visited IL&FS on 19-02-2015 to address the issues relating to frequent

trippings of the lines and the coordinating relay settings in view of LILO made at IL&FS.

NLC:

PLCC equipment has been tested at NLC end and it is working.

SRLDC:

400 kV NLC-1 Exp--- ILFS line tripped again at 06:05 hrs on 05-02-2015 due to PLCC

mal-operation.

End to end testing of PLCC is desired for confirming the correctness of PLCC system.

By 27.02.2015, end-to-end testing of PLCC shall be completed by NLC and SR-II of

PGCIL.

Main 2 distance relay settings shall be revised at NLC-1 Exp by 7th March failing which

the NLC-1 Exp – IL&FS line would be kept open till the completion of the same.

DEF time setting to be revised to 1.1 sec at IL&FS.

PGCIL (SR-II) shall revise the time setting of Zone-3 at Pondicherry (which is 0.8 sec) to

1.0 sec.

Recommendations:

IL&FS, NLC -1 Exp & PGCIL (SR-II) to furnish action taken report on the

recommendations given by SRPC Committee in their meeting held at IL&FS on 19-

02-2015 to SRPC.

4 Tripping of

400/220 kV ICT-3

at Trichur

03-02-2015 at

00:26

ICT tripped due to operation of REF

protection

GI-2

Deliberations:

KSEB:

ICT # 3 tripped due to Restricted Earth Fault Relay operation. This was initiated because

of the heavy arcing from the three pole isolator just before the tripping. Later the Isolator

was inspected thoroughly and it was noticed that there was a gap of about 10 cm between

the male and female contacts.

There was heavy wind blowing across the yard. It was suspected that the Isolator might

have got opened up due to this heavy wind.

It was suspected that corona plates at the tip of male/female contacts could be the cause of

Annexure-III

11

5 Tripping od 400 kV

NLC EXP- ILFS line

05-02-2015 at

06:05 hrs

Line tripped due to direct trip receipt from

IL&FS

GI-2

As per FIR of NLC1 Exp, this line tripped due to DT receipt from IL&FS. Whereas from the

NLC 1 Exp’s DR, no fault seemed to have taken place on this line. Also no DT was received

from IL&FS. (no variation in I and V are observed – ref: DR of NLC 1 Exp).

Recommendations:

IL&FS, NLC 1 Exp & PGCIL (SR-II) to furnish the action taken report on the

recommendations given by SRPC Committee in their meeting held at IL&FS on 19-

02-2015 to SRPC.

6 Tripping of 400kV

Coastal Energen

(CEPL)---NTPL line

07-02-2015 at 01:07

hrs and at 00:08hrs

on 08-02-2015

B-phase to earth fault had occurred in

Line during both instants. As seen from

D.R of Coastal Energen distance relay

sensed fault in zone-2 and earth fault

protection had operated which resulted

in tripping of line.

GI-2

Deliberations:

B-phase to earth fault occurred at NTPL station compound (due to insulator flash-over at

NTPL). But no carrier was sent to CEPL even though the distance relay sensed the fault

and A/R is in service.

CEPL sensed the fault in Zone-2. But even before Zone 2 operation, EFR operated at

CEPL end and sent DT to NTPL.

NTPL end CB tripped due to carrier receipt from CEPL.

SRLDC:

Back up Earth fault relay (EFR) to be blocked when distance protection relay (DPR) is

sensing the fault.

.

PGCIL:

Due to severe pollution and fog at NTPL (coastal area), Insulators cleaning is being

undertaken along with replacing the faulty insulators.

Recommendations:

PGCIL to carry out hot-line washing regularly as NTPL is in highly polluted location.

opening of the contacts by exerting pressure on them. It was decided to review the corona

plates and replace them by corona rings.

It was also being planned to have locking type isolator contacts that would ensure not

opening of the contacts due to heavy wind.

Corrective Action Taken:

The transformer was charged after testing all the parameters and cleaning the

carbonized portion of the isolators.

The matter has been taken up with M/s G.R.Power Switchgear Ltd, the OEM for

studying the exact reason for opening of the isolators and also for design change to be

incorporated in isolators to avoid the recurrence of this kind of incidents in future.

Annexure-III

12

7 Tripping of ICT-1,2&3 at

Hoody substation

07-02-2015 at

17:15 hrs &

19:45 hrs

Arcing observed in 220kV switchyard.

ICT’s were hand tripped load loss was

400MW

GI-2

Deliberations:

KPTCL:

Set-Up:

There are 3x500 MVA, 400/220 kV ICTs and their 220 kV sides are connected to double

bus system; the 220 kV buses are named ‘north’ and ‘south’. There is a 220 kV bus

coupler through which on-load transfer of feeders and transformers (between north and

south buses) are being carried out. 220 kV side is shared by old and new sub stations.

There are 6x100 MVA transformers on old bus.

Cause of of tripping at 17.15 hrs:

LC for ICT-1 was availed to attend the hot spots on 220 kV north bus isolator; after

completion of the work, ICT-1 was connected to south bus.

220 kV bus coupler was charged in order to connect ICT-3, HAL-1 and HAL-2

feeders on north bus.

ICT-3 was transferred from south bus to north bus. Then while trying to transfer

HAL-1 feeder from south bus to north bus, heavy arc was observed that damaged the

north bus isolator contacts of HAL-1 feeder.

It was suspected that bus coupler was open while closing the HAL-1 isolator which

had to carry all the current of ICT-3 from north bus that resulted in heavy arc. All the

feeders and ICTs were hand-tripped to contain the arc.

The bus-coupler control is with the old substation control room and it’s status is not

known to the workmen who are operating the HAL isolators.

Cause of tripping at 19.45 hrs:

Similarly, heavy arc was witnessed while opening HAL-2 north bus isolator. Here

also the open bus coupler during the operation is suspected. ICTs and 220 kV feeders

were hand tripped to contain the arc.

During the disturbance, Bangalore metro was affected for 5 minutes.

Inter lock between bus isolators and bus coupler CB, which is possible under SAS

scheme, is not present at Hoody S/S.

Corrective Action Taken: Strict instructions have been issued to workmen to check the status of the bus coupler

and ensure its closed position while carrying out bus transfer operations.

It was found out that bus coupler CT was with 600/1 A setting which could have

tripped during the transfer operations. Now CT is changed to 900/1 A ratio.

SRLDC:

There has to be interlock between bus coupler CB and feeder isolators so that bus isolators

cannot be operated on-load unless bus coupler CB is closed.

KSEB:

The tripping of bus coupler due to overload (tie current flow) is not recommended.

Since the rating of the bus coupler is based on line loading, its rating should be sufficient

to carry bus loading to avoid unwanted tripping of the system.

Annexure-III

13

8 Tripping of HVDC

Talcher-Kolar pole-2

10-02-2015 at 7:37

hrs

Pole-2 tripped due to ESOF from

Talcher end

GI-2

Deliberations:

It was informed that due to water clogging, there was some differential pressure variation

which inhibited proper working of the pumps at Talcher HVDC.

Pole-2 tripped due to Emergency Switch off (ESOF) from Talcher end due to valve cooling

problem.

HVDC pole-1 went into Metallic Return mode and flow on Pole-1 was 854MW after tripping

of Pole-2.

As there was loss of power, SPS-1 & 3 signals were generated at Kolar end and sent to SR-

Constituents to carry out load shedding.

Load relief of 1457 MW was obtained due to above SPS operation.

SRLDC:

Talcher end Sequence of Events (SOE) has to be obtained and Talcher could be given user id

and password to upload the FIR, DR, EL, Trip analysis reports on SRLDC’s web based

monitoring system.

SRPC:

Similar incident happened on 16-12-2014, and was discussed in the 39th meeting of PCSC;

when PGCIL was asked to carry out testing of the pumps and submit a report to the PCSC

forum, which was still awaited.

,

Recommendations:

PGCIL to test the pumps at Talcher HVDC during pole shut-down and submit the report

to PCSC forum.

9 Tripping of 400KV

Jeypore-Gajuwaka line-

1&2 and HVDC Pole-

1&2 at Gajuwaka

10-02-2015 at

16:24 hrs

Tripped due to disturbance in southern

Odisha.

GI-2

Deliberations:

It was noted that owing to disturbance in Southern Odisha, severe voltage fluctuations

(100kV to 450kV) experienced over Jeypore – Gajuwaka 400 kV D/C line.

Due to this, HVDC Pole-2 tripped due to “Low DC voltage trip” and Pole-1 tripped due to

“Valve winding AC under voltage fault”. The poles were carrying 300 MW each at the

time of tripping.

Subsequently, Jeypore - Gajuwaka line tripped at Jeypore end on operation of Over

Voltage relay, Stage II protection; Gajuwaka-end CBs tripped due to receipt of DT from

Jeypore end.

It was also reported that 400kV Indravati-Rengali, 400 kV Jeypore-Bolangir, 400kV

Jeypore-Indravati lines in eastern region tripped on over voltage.

10 Tripping of Hassan-

UPCL line-2

12-02-2015 at 15:57

hrs

Line tripped due to high resistance fault

in B-phase. DEF picked up at hassan

end and DT was sent to UPCL. DEF

protection did not pick up at UPCL

GI-2

Annexure-III

14

Deliberations:

The line tripped due to high resistance fault in B-phase. Directional Earth fault (DEF) relay

picked up at Hassan end and DT was sent to UPCL.

Distance or DEF protection did not sense the high resistance fault at UPCL.

KPTCL:

It was a slow developing fault.

At UPCL, DEF relay current setting is 600A (primary) and 0.3 A (secondary) on 2000/1 A

CT. Once it picked up it will wait for 1.5 seconds (IDMT) before issuing trip command.

Usually the operation order of the relays (in increasing time) is: Zone-3, A/R dead-time,

Pole Discrepancy and DEF.

SR-II:

DEF current setting at Hassan is 200A (primary) on 3000/1 CT; time dial setting is at 0.6

(normal inverse). If current through the neutral is above 600A, it will trip after 3 seconds.

SRLDC:

Need to review the Directional Earth fault settings at both ends.

The DEF settings at both the station should be kept same.

DEF pick up settings at UPCL to be reviewed in coordination with KPTCL.

Recommendations:

UPCL to revise their DEF relay settings.

11 Tripping of 400kV

BTPS - Hiriyur line-2

13-02-2015 at

17:07hrs

Line tripped at BTPS end only. GI-2

Deliberations:

BTPS-Hiriyur Line 2 tripped at BTPS end only; The line was holding from Hiriyur S/S.

86 A and 86B relays operated at BTPS tripping the line. But no DT was sent to Hiriyur.

Suspected case of PLCC mal-operation.

KPCL:

Some PLCC works were going on at Hiriyur station.

Recommendations:

KPCL to furnish remedial measures taken to prevent recurrence of PLCC mal-operation at

BTPS.

12 Tripping of 400KV

Coastal-NTPL line

13-02-2015 at 22:54

hrs

Line tripped B-phase to earth fault and

later tripped on R-Y phase fault. From

Coastal end D.R, Y & B poles of

breaker opened first and R-pole appears

to be opened on Pole discrepancy.

GI-2

Deliberations:

Annexure-III

15

B-phase to earth fault occurred at NTPL compound. This led A/R to open B phase CB.

However at CEPL end, the fault was sensed in Zone-2, and a 3-phase trip was given by

distance relay; but only Y & B poles of the breaker got opened as a result; the R-pole of the

breaker opened on operation of Pole Discrepancy relay.

Due to persistent fault, the R and Y poles of the breaker opened on R-Y phase fault at NTPL

end.

Single phase Auto-reclosure was unsuccessful at CEPL end.

SRLDC:

Need to check Auto reclosure scheme at CEPL end.

SRPC:

Need to check working of CB at CEPL end.

Recommendations:

CEPL to check A/R scheme at their end.


NTPL-Tuticorin

pooling station

13-02-2015 at 23:12

hrs

Line tripped on R-phase to earth fault at

22:53 hrs. Line auto reclosed at

Tuticorin pooling end and holding. At

23:12 line tripped on B-phase to earth

fault in zone-2 time.

GI-2


NTPL-Tuticorin

pooling station

14-02-2014 at 1:41

hrs

B-phase to earth fault had occurred and

line auto reclosed at 01.09 Hrs and

holding from Tuticorin PS end and line

was and up hand tripping at 01.44.

GI-2


NTPL-Tuticorin

pooling station

14-02-2014 at 6:55

hrs

Line tripped on B-phase to earth fault.

Line did not reclose at NTPL end

GI-2

Deliberations:

MS suggested that NTPL to be invited to meeting to discuss the trippings involving NTPL

station.

PGCIL:

Due to severe pollution and fog at NTPL (coastal area), Insulators cleaning is being

undertaken along with replacing the faulty insulators.

Recommendations:

PGCIL to carry out hot-line washing regularly as NTPL is in highly polluted location.

NTPL to review A/R scheme at their end.

Madurai NTPL

Coastalgen

(CEPL)

Tuticorin Pooling Station

Annexure-III

16

16 Tripping of 400 kV

NEYVELI TS 2 -

PUGALUR

15-02-2015 at 18:38

hrs

Line tripped at pugalur end due to direct

trip receive

GI-2

Deliberations:

The line got tripped at Pugalur end due to the DT receipt.

However, there was no fault at NLC TS-2.

PLCC mal-operation was suspected at Pugalur.

Recommendations:

PGCIL to check the protection coupler of PLCC system at Pugalur end.

III Tripping events due to PLCC Mal-operation:

Sl. No.

Element Date & Time

Reason PCSC Deliberations

1 Tripping of 400kV

Gooty-Somanahalli

line

20-01-2014

at 11:44 hrs

line tripped at Gooty

end only and was

holding from

Somanahalli end line

Recommendations:

PGCIL to furnish remedial

measures taken.

PGCIL to properly tune PLCC

panels. 2 Tripping of 400kV

Udumalpet-Palakad

line-1& 400

Udumalpet-Arasur

line-2

09-02-2015

at 9:50hrs PLCC of Udumalpet-

Arasur-2 mal-operated Recommendations:

PGCIL to furnish remedial

measures taken.

PGCIL to properly tune PLCC

panels.

IV. Tripping events due to failure/ non-operation of Auto-Reclose (A/R) during

Transient fault:

S.No Element Date &

Time Reason PCSC Deliberations

1 400 kV Hyderabad -

Malkaram 24-01-2015

at 06:34 hrs Line tripped on R-

phase to earth fault.

Line did not auto

reclose at Hyderabad

end.

PGCIL: CB locked-out due to low air

pressure.

2 400kV Tuticorin PS-

NTPL line 09-02-2015

at 03:17 hrs Y-phase to earth fault

had occurred in line.

Line auto reclosed at

Tuticorin PS end and

failed to reclose at

NTPL end.

Recommendations: NTPL to check A/R scheme at

their end.

3

400 kV RAICHUR -

MUNIRABAD 17-02-2015

at 07:05hrs Line tripped on R-

phase to earth fault.

Line did not auto

reclose at Raichur

end.

KPCL:

Micromho relay will be

replaced by Siemens make

numerical relay.

Annexure-III

Pending Remedial Measures/ Action taken

for the Critical Tripping Incidents (as on 12.03.2015)

SN Element Name Outage date/time

Revival date/time

Reason for Outage Remedial Measures/ Action taken

1 220 kV AMBEWADI - PONDA 1 06-01-2015/ 12:01:00

06-01-2015/ 12:20:00

TRIPPED ON EARTH FAULT To-be-discussed

2 HVDC BHADRAVATHI POLE 2 08-01-2015/ 09:57:00

08-01-2015/ 10:16:00

NON VALID TAP CODE To-be-discussed

3 220 kV NEYVLI - BAHOOR 11-01-2015/ 15:42:00

11-01-2015/ 17:26:00

R-N FAULT To-be-discussed

4 400 kV VIJAYAWADA - NELLORE 1 22-01-2015/ 11:39:00

22-01-2015/ 11:56:00

DIFFERENTIAL PROTECTION OPERATED

To-be-discussed

5 400 kV SRISAILAM-MAMIDIPALLI 2 23-01-2015/ 16:10:00

23-01-2015/ 19:28:00

BUS2 DEAD WHILE CONVERTING SSLM GEN TO COND. MODE

To-be-discussed

6 400 Kv SATTENAPALLI - SRISAILAM 1 23-01-2015/ 16:10:00

BUS2 DEAD WHILE CONVERTING SSLM GEN TO COND. MODE

To-be-discussed

7 400 kV NLC EXP- ILFS 24-01-2015/ 13:15:00

24-01-2015/ 16:52:00

TRIPPED ON R-N FAULT To-be-discussed

8 400 kV NLC EXP- ILFS 27-01-2015/ 10:05:00

27-01-2015/ 11:20:00

CONTROL CKT PROBLEM @ ILF &S To-be-discussed

9 400 kV RAMAGUNDAM - N'SAGAR 1 03-02-2015/ 16:23:00

03-02-2015/ 16:40:00

LR PRV OPERATED @ NSR To-be-discussed

10 400 kV NLC EXP- ILFS 05-02-2015/ 06:05:00

05-02-2015/ 07:14:00

PLCC MALOPERATION AT NLC 1 EXP

To-be-discussed

11 400 Kv COASTAL - TTRNPS 07-02-2015/ 01:07:00

DISTANCE PROTECTION ACTED To-be-discussed

12 400 Kv COASTAL - NTPL 08-02-2015/ 00:08:00

B-N FAULT To-be-discussed

13 400 Kv UDUMALPET - PALLAKAD 1 09-02-2015/ 09:50:00

09-02-2015/ 09:58:00

PLCC MALOPERATION To-be-discussed

Annexure-IV

14 400 Kv UDUMALPET - PALLAKAD 2 09-02-2015/ 09:50:00

09-02-2015/ 09:58:00


15 400 Kv NTPL - TTRNPS 09-02-2015/ 03:17:00

TRIPPED DUE TO HEAVY ARCING AT NTPL END

To-be-discussed

16 HVDC GAJUWAKA POLE 2 10-02-2015/ 16:25:00

10-02-2015/ 18:49:00

SOUTHERN ORISSA DISTURBANCE To-be-discussed

17 400 kV JEYPORE - GAZUWAKA 1 10-02-2015/ 16:24:00

10-02-2015/ 17:17:00



10-02-2015/ 20:20:00



10-02-2015/ 17:54:00

SOUTH ORISSA DISTURBANCE To-be-discussed

20 400/220 kV ICT-2 AT HIRIYUR 11-02-2015/ 14:56:00

11-02-2015/ 14:57:00

TRIPPED DUE TO NTAMC WORK To-be-discussed

21 400 Kv NTPL - TTRNPS 13-02-2015/ 23:12:00

14-02-2015/ 00:15:00

B - N FAULT To-be-discussed

22 400 Kv HIRIYUR-BTPS 2 13-02-2015/ 17:07:00

13-02-2015/ 17:20:00

TRIPPED AT BTPS To-be-discussed

23 400 Kv COASTAL - NTPL 13-02-2015/ 22:54:00

REASON AWAITED To-be-discussed

24 400 Kv NTPL - TTRNPS 14-02-2015/ 01:41:00

DISTANCE PROTECTION To-be-discussed

25 400 Kv NTPL - TTRNPS 14-02-2015/ 06:55:00

14-02-2015/ 08:49:00


26 220 kV PONDYCHERRY- BAHOOR 15-02-2015/ 11:20:00

15-02-2015/ 14:23:00

TRIPPED ON OVER CURRENT To-be-discussed

27 400 kV NEYVELI TS 2 - PUGALUR 15-02-2015/ 18:38:00

15-02-2015/ 18:51:00

TRIPPED DUE TO PLCC MALOPERATION

To-be-discussed

28 220 kV NEYVLI - BAHOOR 15-02-2015/ 11:20:00

15-02-2015/ 13:13:00

TRIIPED ON OVER CURRENT To-be-discussed

29 400 kV TALAGUPPA - NEELAMANGALA 18-02-2015/ 16:04:00


30 400 kV MUNIRABAD - GUTTUR 18-02-2015/ 07:40:00

18-02-2015/ 12:44:00


Annexure-IV

31 400 kV GHANAPUR - MAMIDIPALLY 18-02-2015/ 12:12:00

18-02-2015/ 12:12:00


32 400 kV KHAMMAM - KALPAKKA 1 18-02-2015/ 12:58:00

18-02-2015/ 14:28:00


33 400 Kv COASTAL - NTPL 19-02-2015/ 16:53:00

19-02-2015/ 17:17:00

TRIPPED DUE TO LOW VOLTAGE To-be-discussed

34 400 Kv COASTAL - TTRNPS 19-02-2015/ 16:37:00

19-02-2015/ 16:56:00

DT RECIEVED AT COSTAL END To-be-discussed

35 220 Kv CHIKKODI - MUDUSHINGI 20-02-2015/ 06:40:00

20-02-2015/ 07:36:00

TRIPPED DUE TO R-PH FAULT To-be-discussed

36 400 kV MALKARAM - HYDERABAD 20-02-2015/ 10:37:00

20-02-2015/ 10:52:00


37 220 Kv CHIKKODI - TALANDGE 20-02-2015/ 06:40:00

20-02-2015/ 08:07:00

TRIPPED AT CHIKKODI END To-be-discussed

38 400 kV KAIGA - GUTTUR 2 21-02-2015/ 14:18:00

21-02-2015/ 18:47:00


39 400 kV MUNIRABAD - GUTTUR 21-02-2015/ 00:26:00

21-02-2015/ 00:43:00

DT RECIEVED To-be-discussed

40 400/220 kV ICT-1 AT NEELAMANGALA 22-02-2015/ 16:58:00

22-02-2015/ 18:17:00

TRIPPED DUE TO B-PH LA FAILURE To-be-discussed

41 220 kV KANIAMPET - KADAKOLA 22-02-2015/ 16:25:00

22-02-2015/ 16:51:00


42 400/220 Kv ICT-2 AT BIDADI 22-02-2015/ 16:58:00

22-02-2015/ 20:15:00

TRIPPED DUE TO TRANSIENT EART FAULT DUE TO TRIPPING OF NLM ICT

To-be-discussed

43 HVDC TALCHER - KOLAR POLE 1 AT TALCHER

23-02-2015/ 15:37:00

23-02-2015/ 15:55:00

TRIPPED WHILE TAKING DC FILTERS To-be-discussed


23-02-2015/ 21:46:00

DT RECIEVED FROM JEYPORE To-be-discussed


23-02-2015/ 18:03:00

DUE TO TRIPPING OF INCOMING LINES

To-be-discussed

46 400 Kv NTPL - TTRNPS 23-02-2015/ 04:42:00

INSULATOR FLASHOVER To-be-discussed

47 400 Kv NTPL - TTRNPS 24-02-2015/ EARTH FAULT To-be-discussed

Annexure-IV

04:30:00

48 400 kV TALAGUPPA - NEELAMANGALA 24-02-2015/ 11:11:00

24-02-2015/ 11:16:00


49 765/400 kV ICT-1 at RAICHUR 25-02-2015/ 18:32:00

25-02-2015/ 20:32:00

MALOPERATION OF WINDING TEMPERATURE INDICATION

To-be-discussed

50 400 kV N'SAGAR - CUDDAPPA 2 26-02-2015/ 17:23:00

26-02-2015/ 18:06:00

Y-N FAULT To-be-discussed

51 400/220 Kv ICT-1 AT SATTENAPLLI 26-02-2015/ 10:19:00

26-02-2015/ 11:30:00

GROUP - A PROTECTION OPERATED To-be-discussed

52 400/220 kV ICT-3 AT GAJWEL 27-02-2015/ 02:32:00

27-02-2015/ 02:53:00

TRIPPE ON MALOPERATION To-be-discussed

53 400 kV HIRIYUR - NELAMANGALA 2 27-02-2015/ 17:19:00

27-02-2015/ 17:21:00

DT RECEIVED AT NLM To-be-discussed


28-02-2015/ 01:19:00

TRIPPED AT GAJUWAKA END ON R-N FAULT

To-be-discussed

55 400 kV NLC EXP- ILFS 28-02-2015/ 19:17:00

28-02-2015/ 20:50:00

TRIPPED AT NLCTS1EXP END To-be-discussed

56 220 Kv CHIKKODI - MUDUSHINGI 01-03-2015/ 03:37:00

BUS DEAD AT MUDUSHINGI END To-be-discussed

57 220 Kv CHIKKODI - TALANDGE 01-03-2015/ 03:37:00

BUS DEAD AT TALANDGE END To-be-discussed

58 220 kV AMBEWADI - PONDA 1 01-03-2015/ 04:21:00

01-03-2015/ 04:57:00

Y - N FAULT To-be-discussed

59 400 Kv COASTAL - NTPL 02-03-2015/ 03:51:00

B - N FAULT To-be-discussed

60 400/220 kV ICT-1 AT TRICHUR 03-03-2015/ 17:02:00

03-03-2015/ 17:54:00

BUS BAR PROTECTION OPERATED AT MADAKATHRA

To-be-discussed

61 400/220 kV ICT-2 AT HOODY 03-03-2015/ 23:44:00

04-03-2015/ 04:27:00

TRIPPED DUE TO OIL SURGE RELAY To-be-discussed

62 400/220 kV ICT-2 AT TRICHUR 03-03-2015/ 17:02:00

03-03-2015/ 17:55:00

BUS BAR PROTECTION OPERATED AT MADAKATHRA

To-be-discussed

63 400/220 kV ICT-3 AT HOODY 03-03-2015/ 23:44:00

04-03-2015/ 03:43:00

BUCCHOLZ RELAY OPERATED To-be-discussed

Annexure-IV

64 400/230 kV ICT-2 AT SALEM 03-03-2015/ 21:30:00

04-03-2015/ 00:17:00

TRIPPED DUE TO RELAY MALOPERATION

To-be-discussed

65 765/400 kV ICT-1 at RAICHUR 03-03-2015/ 12:23:00

03-03-2015/ 13:26:00

TRIPPED To-be-discussed

66 400 Kv RAICHUR PG - GOOTY 1 04-03-2015/ 12:31:00

04-03-2015/ 12:45:00

TRIPPED DUE TO NTAMC WORK To-be-discussed

67 400/230 kV ICT-2 AT SALEM 04-03-2015/ 21:45:00

OIL SURGE RELAY OPERATED To-be-discussed

68 220 kV UPPER SILERU - BALIMELA 04-03-2015/ 08:00:00

LBB OPERATED AT UPPER SILERU To-be-discussed

69 400 Kv SATTENAPALLI - SRISAILAM 2 04-03-2015/ 14:25:00

04-03-2015/ 15:08:00

R-N FAULT To-be-discussed

70 400/230 kV ICT-2 AT SALEM 04-03-2015/ 19:55:00

04-03-2015/ 21:11:00

OIL SURGE RELAY OPERATED To-be-discussed

71 400/220 kV ICT-1 AT MUNIRABAD 08-03-2015/ 19:41:00

08-03-2015/ 20:52:00

DEF OPERATED To-be-discussed

72 400 kV DICHIPALLY - RAMAGUNDAM 09-03-2015/ 00:56:00

B-N FAULT IN ZONE 1 To-be-discussed

73 400/220 kV ICT-2 AT RAICHUR 09-03-2015/ 06:36:00

09-03-2015/ 13:07:00

REASON AWAITED FROM KPTCL / RCR

To-be-discussed

74 400/220 kV ICT-2 AT MAHABOOB NAGAR 09-03-2015/ 07:57:00

09-03-2015/ 19:16:00

RESTRICTED EARTH FAULT To-be-discussed

75 400 kV MAHABOOB NAGAR - RAICHUR 09-03-2015/ 06:36:00

09-03-2015/ 07:55:00


To-be-discussed

76 400 Kv RAICHUR - RAICHUR PG 1 09-03-2015/ 06:36:00

09-03-2015/ 08:18:00


To-be-discussed

77 400 Kv RAICHUR - RAICHUR PG 2 09-03-2015/ 06:36:00

09-03-2015/ 08:02:00


To-be-discussed

78 400 kV MADURAI - PUGALUR 1 10-03-2015/ 19:18:00

10-03-2015/ 20:20:00

TRIPPED AT PGLR END DUE TO MAIN CB FAILURE ALARM

To-be-discussed

Annexure-IV

Meeting

No / Index

Details of Event Date Reason PCSC Recommendations Utility Responsible

for implementation

Status of Recommendations

as on 13.03.2015

Remarks

39/III/1 Tripping of 400kv

VTPS-Satenapalli line-

1 &2

10, 11, 13, 14,15

Dec 2014 voltage.

and grading in over voltage

protection needs to be verified.

PCSC forum recommended APTRANSCO to check up the

drop off to pick up ratio of the Overvoltage relay and correct

it (if needed).

APTRANSCO/

APGENCO

APTRANSCO informed vide their e-mail dated

27.02.15 that the issue pertains to APGENCO.

Pending

40/IV/2 400 kV HYDERABAD -

KURNOOL line

07-01-2015

at 6:17 hrs

Line tripped on Rphase to earth

fault. A/R lock out

observed in E.L of Hyderabad

end

APTRANSCO was requested to check up the A/R feature at

both the ends and submit the remedial measures to the PCSC

forum.

APTRANSCO Yet to be informed Pending

30/I/A RTPS Tripping incidents

and the Spl meeting held

at RTPS on 13th and 14th

March 2014

Mar-14 Spl meeting held at RTPS on

13th

and 14th

March 2014

The PCSC forum recommended for replacement of existing

electromechanical relays with Numerical relays.

KPCL 1. e- Tender folated for the retrofit of existing static

relays with Numerical version for lines

M.nagar,M.bad,ICT-1 & 2 -Technical Bid opened

& price bid yet to be opened.

2. Retrofit of existing bus bar (CAG-34) with

numerical version -Budgetetory offers obtained and

is under process.

3. Order placed on M/s Siemens to replace relays.

The work will be Completed by May - 2015.

Pending

33/II/3 400kV

Hiriyur-BTPS line-2

22-05-14 &

23/05/2014

B phase to ground fault had

occurred in line and line auto

reclosed at Hiriyur end but

failed to reclose at BTPS end.

The PCSC forum requested KPCL to enable the A/R feature at

RTPS end before next PCSC meeting (i.e. 31st July, 2014.

KPCL 1. A/R for 220kV lines enabled already.

2. Shtu down of lines availed to commission the

auto reclosing schme fro 400 kV line at BTPS.

3. A/R shall be enabled in next shutdown

Pending

34/III/1 400kV

Raichur-BTPS line

26-06-2014 Transient fault in R-phase.

Line did not auto reclose

A/R at BTPS end to be made operational within one month KPCL 1. A/R for 220kV lines enabled already.

2. Shtu down of lines availed to commission the

auto reclosing schme fro 400 kV line at BTPS.

3. A/R shall be enabled in next shutdown

Pending

Pending Implementation of PCSC Recommendations (30th to 40th)

Andhra Pradesh

Telangana

Karnataka

Annexure-V

38/GD/3.5 GD-1 at Kadra and

Kodasalli hydro power

station

13-11-2014 at

19:31hrs

A fault had occurred in 220 kV

Kadra and

Kodasalli. As A result, de-

energization of

220kV bus occurred at Kadra

and

Kodasalli.

1. The PCSC forum requested KPCL to speed up the

installation of Numerical Distance Protection relay in Kadra

–Kaiga and Kodasalli –Kaiga.

2. The PCSC forum requested KPCL to submit the

implementation status of PSAG-10 recommendations within a

week’s time.

KPCL All the recommendations of PSAG - 10 are

completed except the following pending issue:

i)e-NIT floated on 28.07.2014 for procurement of

Numerical distance relays & GPS. Bid evaluation

is under progress. The work will be completed by

December - 2015. Hower, as per the

recommendations of PSAG, Relays were

temporarily rearranged, replaced and wired up.

testing & commissioning shall be completed with

the assistance of KPTCL by March 1st week ,

2015.

Pending

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

MUNIRABAD

16-07-2014 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.

4. Correct DR shall be submitted to the SRLDC for trip analysis.

KPTCL Management approval is obtained for taking up the

work of providing bus bar protection to 220kV

buses at Guddadahally (Munirabad) Sub Station

along with replacement of 3 core/age old CTs of

220kV bays belong to KPTCL.

Under implementation

Pending

38/GD/3.1 GD-1 at Mahalingapura

Substation of KPTCL

25-10-2014 Fault had occurred in 220kV

Mahalingapura-Narendra line-

2. Due to the

failure of relay operation at

Mahalingapura,

breakers at remote end tripped

which

resulted in bus dead condition.

1. PCSC forum recommended KPTCL to replace the old static

distance protection relays with numerical relays.

2. PCSC forum also requested KPTCL to provide a broken

conductor alarm indication in Control Room.

3. Standing instruction needed to be given to the all substation

personnel for not changing the relay settings without approval of

RT/MRT wing.

KPTCL Yet to be informed Pending

38/GD/3.2 GD-1 at Guttur

Substation of KPTCL

05-11-2014 at

11:42 hrs

Circuit breaker of 400kV

Guttur-Hiriyur

line-1 failed at Guttur end while

availing

shutdown for replacement of

CVT. The

failure of breaker caused bus

fault at Guttur.

KPTCL was requested to expedite the early implementation of

pending recommendations of:

1. Protection Audit (Phase-I & Phase-II)

2. PSAG-4, PSAG-5, and PSAG-8


39/I/5 Tripping of 400/220kV

ICT-2 at Hoody

substation of KPTCL

01-12-2014 Suspected mal-operation of

220kV side Rphase

over current relay

1. PCSC forum recommended KPTCL to replace the relay with

a different make.

2. KPTCL was also requested to train the O&M personnel

adequately before performing any maintenance works to avoid

such unwanted trippings.


39/I/8 Tripping of 220kV

Chikodi-Talandage&

220kV Chikodi-

Mudshingi lines

01-12-2014 Talandge line tripped at

Chikkodi

end on Back up protection.

Meanwhile Mudashinge line

tripped

at Maharastra end on

DPR,Zone-2.

KPTCL was requested to get tripping report details from the

stations (i.e. Talandage, Mudashinge and Chikodi) and furnish

them to PCSC forum.


Annexure-V

39/I/10 Tripping of

Neelamangala- Hoody

Ckt-1&2 along with

Hoody ICT-2

13-12-2014 It was reported that bus bar

protection

got operated at Hoody

substation.

Reason for the operation of bus bar protection relay and

remedial measures shall be submitted to PCSC forum.


40/I/1 GD-1 at 220kV

Ambewadi Station of

KPTCL

22-12-2014 at

21:22 hrs

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.

1. Till the completion of R&M works for bus bar and LBB

protection, KPTCL shall explore the possibility of having split

bus operation at Ambewadi and submit the details of the same

to PCSC forum.

2. KPTCL shall check up the ICTs protection system for

finding the cause of not tripping for the line fault (through fault)

and submit the remedial measures.

3. KPTCL shall provide the details of the tripping of Supa hydro

station connected downstream from 110 kV bus.


40/IV/1 220kV Sedam-

Tandur line

20-12-2014

at 22:20 hrs

Line tripped on Yphase to earth

fault from both the ends

KPTCL was requested to explore the possibility of providing

A/R feature to this line and submit the remedial measures to the

PCSC forum.


36/II/9 400kV Arasur-Mettur

Line I

29-09-2014 Mettur S/s to Enable A/R Scheme. TANTRANSCO 1. During the 38th PCSC meeting, TANTRANSCO

informed that the Auto Reclosing facility would be

enabled within 15 days.

2 A/R scheme will be implemented after the

commissioning of 400 kV Thiruvalam Line-I & II.

Pending

37/II/3 400kV Mettur-Arasur

line-1

29-09-2014 Line tripped due to Y-Phase to

earth fault.

Line did not auto reclose as

Auto reclose scheme is kept in

non-auto mode.

A/R scheme to be enabled. TANTRANSCO 1. During the 38th PCSC meeting, TANTRANSCO



2. A/R scheme will be implemented after the


Pending

38/II/3 Tripping of 400kV

Mettur-Arasur line-2

22-10-2014 Line tripped on Rphase

to earth fault.

non-auto mode.

A/R feature to be enabled. TANTRANSCO 1. During the 38th PCSC meeting, TANTRANSCO



2. A/R scheme will be implemented after the


Pending


Kayathar-Karaikudi

line-2 at ICT-1,2&3 at

kayathar

07-01-2015 at

23:25 hrs

B-Ph CT of ICT-2 failed

resulting in operation of busbar

protection of Bus-2 and

differential protection of ICT-2

PCSC forum recommended TANTRANSCO to bring Bus-1

also into service to avoid complete outage of the 400kV bus at

Kayathar Substation.

TANTRANSCO Yet to be informed Pending

Kerala

Tamil Nadu

Annexure-V

38/GD/3.3 GD-1 at North Kerala

System

11-11-2014 at

02:02hrs

De-energization of 220kV bus

occurred at Areakode,

Madakathara and Shoranur.

1. The PCSC forum requested KSEB to submit the complete

analysis report of the Grid disturbance (i.e with DR, EL and

KSEB substation connectivity diagram) with the remedial

measures taken within a week’s time to SRPC Secretariat.

2. KSEB shall initiate measures for the following and report the

status to PCSC forum by next PCSC meeting:

(i) to rectify the trip coils at Shoranur on Areakode line CB

(ii) to check the healthiness of trip coils at all other stations

also.

(iii) to make LBB protection functional at Shoranur s/s.

(iv) to have trip circuit supervision provision with

annunciation, if feasible.

3. The status of implementation of SPS (meant for lines at

Madakathara S/S) shall be communicated to PCSC forum by

next PCSC meeting.

KSEB Pending

38/GD/3.4 GD-1 at North Kerala

System

12-11-2014 at

17:37 hrs

De-energization of 220kV bus

occurred at Areakode,

Kanhirode and Orkattery.

1. The PCSC forum requested KSEB to submit the complete

analysis report of the Grid disturbance (i.e with DR, EL and

KSEB substation connectivity diagram) with the remedial

measures taken within a week’s time to SRPC Secretariat.

2. Uniform settings for A/R feature shall be kept at both the ends

of the line.

3. Provision of alarm feature shall be considered for indicating

low pressure in Circuit Breaker system.

KSEB Pending

34/I/3 Tripping of HVDC

Bhadravati Pole-1 & 2

09-07-2014 As reported, pole-1&2 tripped

due to auxiliary supply failure.

1. The PCSC forum recommended PGCIL, SRTS-I take up the

issue with WRTS to submit the report as per IEGC guidelines.

2. SRLDC is also requested to write a letter to WRLDC to

submit the reports to SR also.

3. Based on the SRTS/SRLDC correspondences, SRPC would

take it up with WR and PGCIL if the issue is not getting

resolved.

4. Complete analysis of the faults and rectification/remedial

action taken to avert similar occurrence in the HVDC Back to

Back station shall be submitted.

PGCIL 1. Implementation of Tertiary Winding of ICT for

the auxilliary power supply is going to come up

which resolves this issue.

2. PGCIL informed that all issues would be

discussed during PSAG-11 visit.

Pending

PGCIL

Annexure-V

34/I/7 HVDC

BHADRAVATHI POLE

2

18-07-2014 As reported pole-2 tripped due

on 5th harmonic alarm.

1. Complete analysis of the faults and rectification/remedial

action taken to avert similar occurrence in the HVDC Back to

Back station shall be submitted.

2. The PCSC forum recommended PGCIL, SRTS-I take up the

issue with WRTS to submit the report as per IEGC guidelines.

3. SRLDC is also requested to send a letter to WRLDC to

submit the reports to SR also.

4. Based on the SRTS/SRLDC correspondences, SRPC would

take it up with WR and PGCIL if the issue is not getting

resolved.

PGCIL Yet to be informed Pending

39/I/1 Tripping of 400kV

Gooty-Somanahalli

22-11-2014 Line tripped due to

suspected PLCC

Mal-operation at Gooty

end.

Retrofitting of the relay or installation of Optical Fiber cable is

recommended by PCSC forum to PGCIL.


39/I/9 Tripping of HVDC

pole-2 of Talcher -

Kolar

16-12-2014

due to problem in valve cooling

system.

operated resulting in load

shedding of 1258

MW.

1. PGCIL shall test the pumps during pole shutdown and

submit the report to PCSC forum.

2. PGCIL shall conduct mock test for SPS signals to Kerala and

submit the feedback to PCSC forum.



Vijayawada-Gajuwaka

line

18-12-2014 at

18:33 hrs

Line tripped due to operation of

TEED protection at Gajuwaka

end due to opening of jumper of

Y phase CT.

PGCIL shall review the TEED protection at Gajuwaka end

and submit the details to PCSC forum.


37/I/9 Tripping of 400/220kV

ICT-1&2 at UPCL

04-10-2014 ICT-1&2 tripped during

transient fault in R-phase in

400kV Hassan-UPCL line-1

To avoid tripping of ICTs for line fault, UPCL is requested to

review the settings of ICT’s SEF relay and consider IDMT

setting instead of existing Definite Time setting.

UPCL It has been reported by UPCL that, the work of

review of relay coordination and setings for the

entire plant is given to M//s Alstom for entire

plant. UPCL has furnished the settings given by

M/s Alstom for verification. Revised settings will

be issued this week for implementation

Pending

40/II/8 Tripping of Unit-1 at

Kudankulam

14-01-2014 at

19:20 hrs

Y-phase Differential protection

of Generating transformer of

Unit-1 got operated which

resulted in tripping of Unit-1.

1. NPCIL, Kudankulam was recommended to submit all the

relevant reports of the above incident.

2. PCSC forum also requested NPCIL, Kudankulam to upload

all the reports (DR/EL/ FIR) of any incident in the SRLDC web

portal within 24 hrs of its occurrence.

NPCIL, Kudankulam Yet to be informed Pending

36/II/8 400kV Raichur-

Munirabad line

07-09-2014 B-phase to earth fault had

occurred in line.

Line auto reclosed at

Munirabad end and failed to

reclose at Raichur end.

KPTCL:

PD (pole discrepancy) time delay would be changed.

PGCIL /

KPTCL

Yet to be informed Pending

Others

Miscellaneous

Annexure-V

37/I/6 Tripping of 400KV

Hassan-UPCL line-2

25-09-2014 High resistance fault as the

fault ampere was very less i.e.,

0.6kA at Hassan end and nearly

0.9kA at UPCL end.

Back up earth fault protection

had operated at Hassan.

At UPCL end the high

resistance fault got converted

into a R ph-B-ph fault which

resulted in operation of distance

protection Zone-1.

The reason for non-picking up

of Back up earth fault at UPCL

needs investigation.

1. At UPCL end, unused zones of distance protection

(probably zone 5 to 8) shall be disabled.

2. At UPCL end, time synchronization between main-1 and

main-2 relays shall be ensured.

3. UPCL shall ensure time synchronization with Hassan

substation.

4. Reasons for non operation of back up protection at UPCL

for high resistance fault is to be submitted.

5. Reasons for not sending DT to UPCL by Hassan end is to

be submitted.

6. Settings of UPCL are to be reviewed and informed to PCSC

forum.

UPCL /

KPTCL

It has been reported by UPCL that, the work of

review of relay coordination and setings for the

entire plant is given to M//s Alstom for entire

plant. UPCL has furnished the settings given by

M/s Alstom for verification. Revised settings will

be issued this week for implementation.

Pending


Khammam- Kalpakka

line

11-10-2014 Line tripped on Yphase

to earth fault.

reclose at Khammam

end.

APTRANSCO and TSTRANSCO were requested to clear the

corridor jointly at the earliest.

PGCIL/

APTRANSCO/

TSTRANSCO

Yet to be informed. Pending

38/II/5 400kV Ramagundam-

Hyderabad line-4

27-10-2014

to earth fault.

reclose at Hyderabad

end due to

PLCCmal-operation.

Planned to replace the PLCC system within a week's time at

both the ends during the shutdown.

NTPC/ PGCIL Yet to be informed. Pending

38/III/10 Tripping of

400kV Hassan-

UPCL line-2

19-10-2014 operation of over voltage

protection at UPCL end

KPTCL and UPCL are requested to send the report with details

of the overvoltage tripping.

UPCL / KPTCL Yet to be informed Pending

39/I/2 Tripping of

400Kv Ghanapur-

Mamidipally

line

22-12-14

at 10:52 hrs,

24-12-14 at 11:32

hrs,

24-12-14 at 16:16

hrs

Due to PLCC Mal-operation at

HYD S/S end, DT received at

MMPLY end and line got

tripped.

PGCIL is requested check up with the manufacturer to resolve

the issue and submit remedial measures to PCSC forum.

PGCIL/ TSTRANSCO Yet to be informed. Pending

Annexure-V

1

The PSAG-10 members recommended to replace the Main I (Q21 static

Quadramho relay -SHPM 101) distance protection relays with Numerical relays

having DR and EL features.

e-NIT No. LOT/CEED/EE6/R&M/ Dist.Prot/1416 dtd:

28.07.2014 was floated through e-portal for Supply, Retrofit,

Testing & Commissioning of Numerical Distance protection

relays & GPS for Varahi, Gerusoppa, Kadra & Kodasalli

Power Houses of KPCL. Bid evaluation is under progress.

2The PSAG group also advised KPCL to test the Main II Relay (PZ1000

numerical relay) at the earliest .

Will be completed during last week of March 2015 in

coordination with KPTCL.

3

The PSAG group recommended to have a uniform Zone II time settings as

agreed in the Tripartite meeting of KPCL, KPTCL and Kaiga (NPCIL) held during

11th& 12th of December, 2013) in the Kaiga – Kali Complex.

Completed.

4

The Resistive reach of distance protection relay of Kadra – Kodasalli (both

ends), Kadra – Karwar I, Kadra – Karwar II (Kadra end), Kodasalli – Nagjheri I,

Kodasalli – Nagjheri II (both ends) lines to be increased so as to operate on high

resistance faults within the permissible limits . Since the present settings are

prone to under reach and initiating unwanted tripping at the their locations,

PSAG has recommended to suitably increase the resistive reach of all the lines.

PSAG advised KPCL to revise the settings at the earliest.

Completed.

Compliance to recommendations of Meeting of Protection system Analysis Group (PSAG-10) at Kadra, Kodasalli and

Kaiga held on 12th & 13th November 2014 for discussing the Grid Disturbancea occurred on 26.09.2014 and

05.10.2014

Sl. No. Recommendations KPCL Compliances- Status as on 23.02.2015

Page 1 of 2

Annexure-VI

Sl. No. Recommendations KPCL Compliances- Status as on 23.02.2015

5

PSAG recommended to make the carrier aided protection functional for 220kV

Kadra-Kodasalli, 220kV Kadra-Kaiga and 220kV Kodasalli-Kaiga lines. In

addition, since most of the faults are seen as high resistance fault, PSAG

suggested to revise the existing PUR to POR scheme for all the lines at Kali

complex.






Hence work shall be taken up in coordination with KPTCL

after installation of new relays.

6

The PSAG group noted that most of the faults were in the ‘B’ Phase (of RYB) to

ground faults. The group observed that it may be due to thick vegetation below

Kadra – Kodasalli, Kodasalli - Kaiga line, Kadra – Kaiga line. Hence the PSAG

group members advised to have regular thorough line patrolling and clearing the

corridor (i.e. Right Of Way).

To be implemented by KPTCL

7

PSAG had recommended to have a uniform setting for the backup earth fault

protection (67N) provided through distance relay (i.e PZ1000) and separate back

up earth fault relay (CDD21 of English Electric, electro mechanical) immediately.

Completed.

8The PSAG group advised to disable the phase over current protection in

distance relays (i.e PZ1000 of CSPC make) immediatelyCompleted.

9

KPCL informed that installation of GPS for time synchronization of all relays and

other protection devices is under process. KPCL is requested to expedite the

same.






10

It is suggested to check timings (opening and closing) on Kadra line CB test at

Kodasalli station periodically and the record of checking to be maintained in the

substation

Completed.

11

It was observed that Kodasalli – Nagjheri I & II lines were kept open at Nagjheri

end on 26.09.2014, 5.10.2014 & 14.10.2014 during bus dead conditions at

Kodasalli station. KPTCL (SLDC) is requested to clarify /review the issue

To be implemented by KPTCL/SLDC

12The DR and EL data of the line/unit tripping shall be made available for analysis

at station level / SLDC /SRLDC/SRPC level.Noted

Page 2 of 2

Annexure-VI

id6731031 pdfMachine by Broadgun Software - a great PDF writer! - a great PDF creator! - http://www.pdfmachine.com http://www.broadgun.com

Annexure-VII

Annexure-VII

Annexure-VII

Annexure-VIII

Annexure-VIII

Annexure-VIII

Format for intimating the Failure of Transmission line Towers

1. Name of Transmission line with voltage level:

2. Length of line (km):

3. Type of configuration:

[(S/C, D/C, S/C strung on D/C towers,

narrow base etc.)

4. Number of Towers and Type of Towers failed:

[suspension/ tension/dead end/special tower

/river crossing tower/ Powerline crossing/Railway Crossingetc.,

with / without extension

(indicatethe type & length of extension)]

5. Tower location No. with reference to nearest substation(indicate Name):

6. Name and size of conductor:

7. No. of sub-conductors per bundle and bundle spacing:

8. Number and size of Ground wire/OPGW (if provided):

9. Type of insulators in use(Porcelain / Glass / Polymer):

10. Configuration of insulators (I / V / Y / tension)

11. No. of insulators per string and No. of strings per phase:

12. Year of construction / commissioning:

13. Executing Agency:

14. Weather condition on the date of failure:

15. Terrain Category:

16. Wind Zone (1/2/3/4/5/6) and velocity of wind:

17. Details of earthing of tower (pipe type/ Counter poise):

18. Line designed as per IS:802 (1977/1995/any other code):

19. The agency who designed the line:

20. Any Special consideration in design:

21. Date and time ofoccurrence/discovery of failure:

22. Power flow in the line prior to failure:

23. Any missing member found before / after failure of towers:

24. Condition of foundation after failure:

25. Brief Description of failure:

[alongwith photographs(if available), other

related information like tower schedule,

newspaper clipping for cyclone / wind storm etc.]

26. Probable cause of failure:

27. Details of previous failure of the line / tower :

28. Whetherline will be restored on ERS or Spare tower will be used:

29. Likely date of restoration:

30. Present Status:

31. Details of any Tests carriedout after failure:

32. Any other relevant information:

Annexure-VIII

L1

Group -1 Feeder

1.Brindavan line at Peenya

2.Nelakaradanahalli line at Peenya ~130 MW

3.Widia line at Peenya

4.Telecom Layout line-1 & 2 at NRS

L2

Group -2 Feeder

1.D.G line-1,2 and 4 at Peenya ~150 MW

2.T.G Hally line at Peenya

3.Nandinilayout line at Peenya

Group -3 Feeder

1.Gokula line -1 and 2 line at Peenya

L3 2.Tr-1(20 MVA) & Tr-4(31.5 MVA) at Peenya

3.NRS-2 line at Peenya ~130 MW

4.Tr-1(20 MVA) & Tr-2(20 MVA) at NRS

5.Brigade at NRS

6. Vijayanagar at NRS

NELMANGALA-PEENYA

LINE-2

NELMANGALA-PEENYA

LINE-3

SPECIAL PROTECTION SCHEME FOR NELAMANGALA-PEENYA CORRIDOR as finalized by KPTCL

NELMANGALA-PEENYA

LINE-1

CURRENT IR OR IY GREATER

LINE CURRENT IY CURRENT IR OR IY OR IB GREATER

LINE CURRENT IR

LINE CURRENT IB

LINE CURRENT IY

LINE CURRENT IR

LINE CURRENT IB


CURRENT IR OR IY OR IB GREATER

DELAY OF 1 SECCURRENT >750A

CURRENT MAXOF L1,L2,L3

LINE CURRENT IY

LINE CURRENT IR

LINE CURRENT IB

TRIP GROUP-1 FEEDER

TRIP TR-3 HV BREAKER

TRIP GROUP-2 FEEDER

TRIP GROUP-3 FEEDER

CURRENT IR OR IY OR IB GREATER


DELAY OF 2.5 SEC

DELAY OF 2 SEC

Annexure-IX

Date post:	09-Jul-2018
Category:	Documents
Upload:	dinhcong
View:	235 times
Download:	1 times

SOUTHERN REGIONAL POWER COMMITTEE - Karnataka · SOUTHERN REGIONAL POWER COMMITTEE ... following...

Documents