· tripped on earth fault protection. 5 tripping of 400kv neyveli ts2-neyveli ts2 exp-1 and 400kv...

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.



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.

http://srldc.in/Reports.aspx



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


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


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


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.


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


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: On 23.11.2017 LDP relays commissioned in place of Main-1 distance relay in 400kV NPS-Nellore line-2 & In line-1 installation of

LDP relay is planned in Dec-2017/Jan-2018.


5. PGCIL (SR-I) informed that LDP commissioning on both lines would be completed by February, 2018. In this regard, PCSC made it

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

& comply with the same.

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


4. LDP relays procurement is under process. Procurement will be completed by Feb-2018. TPCIL has to give written confirmation for

LDP relay procurement. For want of written confirmation from TPCIL, PGCIL approving authority has withheld the LDP proposal.


4. PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete procurement of LDP relays. To this,

PCSC forum asked TPCIL to submit written confirmation to PGCIL (SR-I) by 29.12.2017. PGCIL (SR-I) assured that with receipt of above

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

APTRANSCO informed that they would be able to implement LDP from their & APGENCO side by April, 2018.

In this regard, PCSC forum made it clear that the recommendation is about providing LDP as both Main-I & Main-II relays on all stated

lines in Nellore Complex, ans asked all stakeholders to ensure & comply with the same.

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.


1. Week end infeed logic will be enabled in the new numerical relays supplied to Karwar under R&U during retrofitting works.

--- Pending


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


PGCIL may be requested to take necessary action


2. EL procured and drawn. Configuration to be done by Alstorm company engineer. Will be configured in four weeks.

---Pending


2. APTRANSCO is to replace the faulty/outdated relays & POWERGRID has to maintain the relays after retrofitting.


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


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


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


To avoid the unwanted malopeartions due to the external LBB trip initiation from PGCIL, Vide letter Dt: 04-08-2016, APTRANSCO has

requsted the PGCIL to arrange the Master trip relay and breaker contacts of ICT-1 &2 LV side to enable the internal LBB feature in the

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


To avoid the unwanted maloperations due to the external LBB trip initiation from PGCIL, vide letter Dt: 04-08-2016, ARTRANSCO has

requested the PGCIL to arrange the Master trip relay and breaker contacts of ICT-1&2 LV side to enable the internal LBB feature in the

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


Waiting for the PGCIL response.

APTRANSCO mail dated 04.03.2017 & 24.05.2017.

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

APTRANSCO mail dated 20.09.2017 & 22.11.2017

PGCIL may be requested to take necessary 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


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



M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd.


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


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


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


Issue was addressed to the concerned for necessary action.


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

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

Relays procurement for all the locations is under progress.

APTRANSCO Mail dated 15.12.2017:

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


LDP relays procurement is under process. Procurement will be completed by Feb-2018. TPCIL has to give written confirmation for LDP

relay procurement. For want of written confirmation from TPCIL, PGCIL approving authority has withheld the LDP proposal.


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


STG-2

25-04-2017

at 18:27hrs


Unit


STG-2

26-03-2017

at 21:09 hrs


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


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.


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.


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


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:





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


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


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


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)


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.




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)


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


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

Discrepancy is being observed in Ragulapadu - Alipira section only. When enquired about the same, KPTCL informed that they would

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

to render all help required from their side to KPTCL.


APTransco 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:





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


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.


APTRANSCO informed that the recommedned works would be completed by 31.01.2018.


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.


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


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.


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.


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


TSTRANSCO informed that PLCC end-to-end testing would be carried out as recommended by 10.01.2018.


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


3. Work under implementation stage --- Pending


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


3) DPR for implementation of Two Bus operation for 220kV bus system has been prepared and proposal is placed for funds from

PSDF. After the approval of the DPR, the work is proposed to be taken up.


3) KPCL informed that DPR for implementation of Two Bus operation for 220kV bus system has been prepared and proposal is placed

for funds from PSDF. After the approval of the DPR, the work is proposed to be taken up. Time frame requested for is 2 yrs.

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


Tendering under process


KPCL informed that the new numerical relay for backup impedance protection of Line Reactor would be provided by June, 2018.

KPCL Mail dated 19.01.2018:

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

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.


1.(i) --- Pending

1. (ii) Hot line water washing stopped and off line water washing is carried out whenever the 400 KV Unit or line is under tripped

condition / Shutdown condition. --- Completed

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

condition. For remaining breakers, since it is big order, approval for the same is under process --- Pending

2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker flash over protection feature will be enabled (if available) in

the numerical relays which will be retrofitted in phased manner during R&M works --- Pending

.


1 (iii) As upgradation of 400kV switchyard equip's to be taken under PSDF funds, Silicon rubber coating for breakers is deffered till

then. --- Pending

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

make. --- Pending

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.


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


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 coordination with EE(RT), KPTCL, Hubli.


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


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


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


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


Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being taken to restore the carrier protection for

220kV Sedam-Tandoor line. AR will be enabled.


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

2. Action is being taken to restore the carrier protection for 220kV Sedam-Tandoor line. AR will be enabled after restoration of PLCC.

KPTCL mail received on 23-01-2016:

1. Bus bar protection panels pocured and erected at Sedam. Wiring , testing ,commissioning is being taken up.Planned to complete

by April 2016.


KPTCL Mail recieved dated 22-11-2017:

1 & 2). Bus Bar Protection panel and required Wave traps are supplied under R&U. Wave trap to be commisioned in Tandoor line and

PLCC to be restored.Once PLCC is restored AR will be enabled. The Wave traps required are supplied under R&U project and the same

is to be commisioned at Sedam end for restoration of PLCC.


1 & 2) Replacement of Bus Bar Protection is included under R&U project. Awarded to M/s GE Ltd. Panels have alredy been supplied by

the Agency. The work will be taken up on top priority.


KPTCL informed that the works relating to put A/R in service are going on at their Sedam SS, and assured that it would be put into

service by February, 2018.

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.


Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring the carrier protection , AR will be

enabled.


SEE,SCADA to update the latest status


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.



M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd.




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.





Bus Bar Protection panel and required Wave traps are supplied under R&U. Wave trap to be commisioned in Tandoor line and PLCC

to be restored.Once PLCC is restored AR will be enabled.


1. Replacement of Bus Bar Protection is included under R&U project. Awarded to M/s GE Ltd. Panels have alredy been supplied by the

Agency. The work will be taken up on top priority.

2. AR feature will be enabled during retrofitting of Main-2 relays.


1 & 2) KPTCL informed that the works are under progress and are targeted to be completed by February, 2018.

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:



KPTCL Mail Recieved dated 22-11-2017 & 16.12.2017:

1.Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-Ponda and Ambewadi-Xeldom lines are radial

lines, it was decided that enabling AR is not required. To clear the faults in the abovelines early, the timings of the Zone 2 was reduced

to 150mS and the Back Up EFR timings have been reducedto 150mS. --- Completed

2.The planned works as per R&M could not be taken up due to the problem with the vendor and could not be taken up under R&U

project due to administrative reasons. ---- Pending


2. The issue was discussed. Considering the importance of the substation and delay in executing the works, it was decided to escalate

all pending issues relating to Ambewadi SS to KPTCL top Management for early completion.

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.


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.


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.


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.


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.


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.


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


Providing numerical bus bar protection to 400kV buses and GPS time synchronising equipment at Guttur is considered under R&U.

Work is awarded to M/s Alstom, execution will be taken up shortly.


GPS and accessories will be supplied during May 2017, expected to complete the work within a month after supply of materials.


As discussed during the earlier PCSC meetings, current limit of 12.5KA has been added in the logic of AR at Guttur end to prevent

reclosing during failure of LA or any other very close faults. Replacement of existing static BBP by new numerical BBP with Main 1&2

will be taken up at Guttur for which the panels are already supplied. Presently, replacement of 220KV side Bus bar protection is under

progress. DI for delivery of GPS receiver has already been issued, but there is a delay in dispatch of the same by M/s GE Ltd due to GST

issues, which is also addressed recently.


1). The work of replacing static type 400kV Bus Bar Protection scheme by numerical BBP is under progress at Guttur.

--- Pending

2). GPS time syncronising device is expected to be supplied before end of December 2017 --- Pending


1) & 2) KPTCL informed that the works are under progress, and are targeted to br completed by February, 2018.

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.


GE Ltd has already supplied the necessary Bus Bar protection panels for replacement of the existing static type BBP by new numerical

BBP with 4 zone protection under R&U project. The work of commissioning the same will be taken up shortly.


Due to operational constraints two/ multi bus operation is not being implemented.


It was noted that Shimoga SS is having required configuration for providing double-bus operation. However, due to large no. of

feeders (15 in no) with variable gneration at certain remote ends like Varahi, the flows on these lines are bound to vary. As such it is

necessary to zero in on appropriate arrangement of feeders on different buses so that bus-isolators of the feeders are not

overloaded.

The issue was discussed. KPTCL was asked to try out multi-bus operation on trial basis to arrive at suitable arrangement of feeders.

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


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.


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.


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


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.


1. Numerical Bus Bar protection panels have already been supplied as a part of R&M works awarded to GE Ltd. Due to issue regarding

the sectionaliser CTs, the work had stopped. Now the same is resolved and the the above work will be taken up after supply of

sectionaliser CTs. --- Pending

2. --- Pending


1. Numerical Bus Bar protection panels have already been supplied as a part of R&M works awarded to GE Ltd. Due to issue regarding

the sectionaliser CTs, the work had stopped. Now the same is resolved and the the above work will be taken up after supply of

sectionaliser CTs. --- Pending

2. --- Pending


1. KPTCL informed that BBP at 220 kV Hoody would be provided by March, 2018.

---- Pending

2. EFR on failure of R-ph CT of 220/ 66 kV Transformer-2 had been furnished to CEA. ---- Completed

Pending

62/II/5 Tripping of 220 kV South Bus and

connected elements (220kV HSR, 220kV

Nagnathpura, 220 kV Harohalli, 220 kV

Subramanyapura, 220 kV Tataguni, 220 kV

Mallur and 400/220kV ICT-2 and 3) at

400/220kV Somanhalli substation of

KPTCL

(Load loss: 850 MW)

20-01-2017 at 14:34

hrs

Triggering incident was fault in 66 kV Somanahalli -

Bannerghatta line and fault was cleared by operation of

Back-up OCR at Somanahalli end.

KPTCL to provide numerical Busbar Protection at their 220 kV Somanahalli SS at

the earliest.

KPTCL KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works


Tesing & Commissioning of numerical BBP at Somanahalli is under progress. There was some technical issue wth BBP scheme supplied

to Somanahally which is being finalised in consultation with OEM SIFANG. Numerical BBP will be commissioned at Somanahally

within a month's time.


Numerical Bus Bar protection Scheme will be commissioned at Somanahally before end of December 2017

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:



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


2. Modifications to be carried in Nagzari SPS logic is submitted to SRLDC/SRPC for verification and approval


1. Will be reviewed in consultation with EE(RT), KPTCL, Hubli.

3. Both the lines are in charged condition.


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


1) & 3). --- Completed.

2). Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be discussed and approved by the SRPC

forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested certain changes for suitable incorporation. KPTCL agreed

to look into the same and assured that the modified SPS would be furnished by January, 2018.

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.


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


Modifications to be carried in Nagzari SPS logic is submitted to SRLDC/SRPC for verification and approval


1. Tripped since there was evacuation problem and there were only two lines NA-1 and NA-2 ---- Completed

2. Will be reviewed in consultation with EE(RT), KPTCL, Hubli. --- Pending

3. Both the lines are in charged condition. --- Completed.


2. Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be discussed and approved by the SRPC

forum. --- Pending


1) & 3). --- Completed.

2). Proposed revision in existing SPS scheme is already submitted to SRLDC/SRPC., yet to be discussed and approved by the SRPC

forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested certain changes for suitable incorporation. KPTCL agreed

to look into the same and assured that the modified SPS would be furnished by January, 2018.

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


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.


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.


Numerical BBP relay was commissioned on 02.02.2017

Status received vide mail dated 12.04.2017 & 01.06.2017 & 15-06-2017:

Numerical BBP relay was commissioned on 02.02.2017.

Provision of Bus Coupler bay arrangement was included in the Upgradation works proposed and the same was sanctioned by MoP

through PSDF.


Numerical BBP relay was commissioned on 02.02.2017.

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.


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:


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:


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.


Othakalmandapam - Myvadi feeder replacement of kundha conductor with Zebra and tower replacement work has been sanctioned.

Work will be taken up.


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..


TANTRANSCO informed that Numerical BBP would be commissioned by March, 2018.


Commissioning of Numerical Bus bar protection is under progress. Zone segregation will be ensured. Timeline: March-2018.

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


CMR relay for extending LBB protection was released and LBB extended from Distance Protection relay directly. CT is not available in

the Bus Coupler bay for zone segregation. However, during commissioning of third ICT, Bus section Breaker will be provided for zone

segregation. Numerical BBP relay will be provided.

Status received vide mails recieved on 27-04-2016 and 20-05-2016 ,16-06-2016, 25-07-2016, 24-09-2016,10-11-2016 & 20.12.2016

& 12.04.2017 & 01.06.2017 & 15-06-2017:

1 & 2) CT is not available in the Bus Coupler bay for zone segregation. However, during commissioning of third ICT, Bus section

Breaker will be provided for zone segregation. Numerical BBP relay will be provided.


1 & 2) Contract awarded for providing third ICT & Bus modification works to accomodate bus coupler bay. Numerical BBP relay has

been provided and tesing under progress.


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.


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.


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


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.


TANTRANSCO informed that the recommended works of providing different make Relays for Main-I & Main-II are targeted to be

completed by September, 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


2) TANTRANSCO informed that Numerical BBP would be provided by April, 2018

--- Pending


1. Complied.

2. High impedance BBP relay will be replaced by Numerical relay. Timeline: April-2018.

TANTRANSCO Pending

Annexure-II

Page 27 of 34

64/1/4 Complete outage of North Chennai TPS

STG-1

26-03-2017

at 23:14hrs


running Unit at NCTPS Stg-1

1. TANTRANSCO to take steps to complete insulator replacement works on the

230 kV lines owned by them in NCTPS area within 6 months.

2. TANTRANSCO to take steps to implement A/R on all 230 kV lines emanating

from NCTPS-I at the earliest.

TANTRANSCO Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017:

1. All the Porcelain insulators were replaced with Polymer insulators in 230kV NCTPS-I - Tondiarpet feeders - 1 & 2.

---- Completed

2. AR will be implemented on all 230kV lines emanating from NCTPS-I. --- Pending


1. Completed

2. The scheme needs modification to enable AR, since AR was not envisaged for this station during commissioning. AR will be

implemented on all 230kV lines emanating from NCTPS-I within six months. --- Pending


2) TANTRANSCO informed that A/R would be implemented on all 230 kV lines emanating from NCTPS-I by June, 2018.


1. Complied.

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


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


1. Purchase procedures is still in progress --- Pending

2. Replaced. --- Completed.

3. PLCC equipment Tested and found OK --- Completed.


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.


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.


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


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


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]

[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



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




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)


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)


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)


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

· tripped on earth fault protection. 5 tripping of 400kv neyveli ts2-neyveli ts2 exp-1 and 400kv...

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