· 2019-08-20 · Agenda for the 86th Meeting of PCSC scheduled to be held on 4th September, 2019 Page 2 4.2 Remedial measures for "Transmission Elements under Forced Outage" The

Agenda for the 86th

Meeting of PCSC scheduled to be held on 4

th September, 2019 Page 1

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Agenda for the 86th Meeting of Protection Coordination Sub-Committee of SRPC to be held on 4th September, 2019

1. Introduction

2. Confirmation of Minutes of last PCSC meeting

Confirmation of minutes of 85th Protection Coordination Sub-Committee meeting held on 31st July 2019.

3. Grid Occurrences

3.1 Grid Disturbances (GD), Grid Incidences (GI), trippings due to failure of Auto-reclosing

(A/R) and mal-operation of PLCC equipment that occurred during the period July - August, 2019, 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 furnish/bring 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 hr. 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 01.07.2019 – 15.08.2019 had been brought to Constituents’ notice vide letters (i) No. SRPC/ SE-III/ PCSC/ 2019/ 4624-34 dated 19.07.2019, (ii) No. SRPC/ SE-III/ PCSC/ 2019/ 4957-69 dated 07.08.2019 and (iii) No. SRPC/ SE-III/ PCSC/ 2019/5157-72 dated 20.08.2019. Non-compliance in this regard would be discussed in the meeting.

4. Submission of Reports/ Compliance by Constituents

4.1 Status of implementation of Recommendations Protection Coordination

Sub-Committee (PCSC), which are pending

The status of implementation of PCSC recommendations (up to 85th PCSC meeting), which are pending is given at Annexure-II. The latest status on the same may please be sent latest by 28.08.2019.

Agenda for the 86th



4.2 Remedial measures for "Transmission Elements under Forced Outage"

The Constituents are requested to furnish the remedial measures/ actions taken by them for the tripping events as circulated vide this office 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), 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) are required to be obtained by RPC’s from their respective Constituents 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 month of July, 2019 is awaited from the following SR-Constituents:

KPTCL, TANGEDCO, PGCIL (SR-1), NLCIL, NTECL 5. Nominations of Nodal Officers for Conduction of Protection Audit of various 220 kV

& above Stations in Southern Region

As per the discussions of PCSC-80 conduction of protection audit of various 220 kV & above Stations in Southern Region was approved in 35th SRPC meeting. Nominations in this regard were sought from all Utilities vide SRPC letter No. SRPC/SE-III/ PA/ 2019/3589-3618 dated 19.06.2019. NLCIL is requested to urgently furnish nominations in this regard.

Based on analysis of past tripping data nearly 80 stations have been identified as part of the audit. Schedule of the same will be discussed during the meeting.

6. Updating of Protection Audit format

All SR constituents were requested to share their suggestions/ modifications/ deletions required in the protection audit format vide SRPC mail dated 02.08.2019, so as to update the same as per recent trends followed in industry. All constituents are requested to furnish the inputs in this regard before 28.08.2019 for compiling and further discussion in forthcoming PCSC meeting.

7. Report of Standing Committee of experts on failure of 220kV & above voltage class substation equipments

CEA standing Committee of experts on failure of 220kV & above voltage class substation equipments have published their report of failure analysis of 220kV & above voltage class substation equipment for the period January 2017 to March 2018 on CEA website (http://www.cea.nic.in/reports/committee/failure_equipment/failure_1718.pdf) .

This is for the kind information of all constituents.

http://srldc.in/Reports.aspx

http://www.cea.nic.in/reports/committee/failure_equipment/failure_1718.pdf

Agenda for the 86th



8. Other Protection Issues, if any, with the permission of the Chair

9. 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.

10. Date of next PCSC meeting

The tentative date of 87th meeting of PCSC is 23rd October 2019.

*****

Grid Occurrences to be discussed in the 86thMeeting of PCSC scheduled to be held on 4th September, 2019 1/4

Grid Occurrences - 86

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 220kV Kadakola, Hootagally, Vajramangala, TK Halli, Madhuvanahalli and Chamrajnagar stations of KPTCL

25-07-2019 at 12:58hrs

Bus bar protection operated at 220kV Kadakola station due to fault created by arcing in isolator resulting in tripping of all connected elements. 220kV Kadakola station was on single bus operation. There was also complete loss of supply at 220kV Hootagally, 220kV Vajramangala, 220kV TK Halli, 220kV Madhuvanahalliand 220kV Chamrajnagar substations

Load loss –

350MW GD-1

2

Complete Outage of 400kV KTPS VII Generating Station of TSGENCO

04-08-2019 at 18:01hrs

and 06-08-2019 at 23:50hrs

Connected lines got tripped on operation of over voltage protection which in turn lead to de-energization of 400kV Bus-1 & 2.

GD-1

3

Complete outage of 220kV/132kV Paravada SS of APTRANSCO

08-08-2019 at 11:34 hrs

Triggering incident was failure of Y-ph LA of 220kV Paravada- VSS(Vizag Switching Station) line at Paravada end.

Load loss – 84 MW

GD-1

II. Details of Grid Incidents:

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

1 Tripping of 400kV Krishnapatnam-Nellore-1

01-07-2019 at 03:40 hrs, 03-07-2019 at 3:42 hrs, 19-07-2019 at 2:25 hrs, 21-07-2019 at 2:27 hrs, 28-07-2019 at 1:40 hrs, 28-07-2019 at 23:39 hrs

Line tripped on operation of over voltage stg-1 protection at Krishnapatnam and direct trip was received at Nellore. The Y –phase CVT voltage at Krishnapatnam end was observed to be 8 to 10 kV higher than the R & B phase voltages.

GI-2

Annexure-I


2 Tripping of 400kv Kalpakka-Asupaka line-1

01-07-2019 at 15:59 hrs; 20-07-2019 at 21:00 hrs

Line tripped on operation of over voltage stg-1 protection at Asupaka and direct trip was received at Kalpakka. 8 to 10 kV voltage difference was observed between R, Y & B phase voltages.

GI-2

3 Tripping of 400kV Guttur-Hiryur line-1

01-07-2019 at 18:02 hrs; 02-07-2019 at 1:20 hrs

Line tripped on operation of over voltage stg-1 protection at Guttur and direct trip was received at Hiryur. However, over-voltage stg-1 operation could not be validated from DR of Guttur end as the volatges were less than O/V pick up

GI-2

4 Tripping of ICT-1&2 at 400/220kV Hoody Substation

01-07-2019 at 09:20 hrs

ICT’s got tripped on operation of back up earth fault protection. CB failure occurred during charging of 220kV Hoody-HSR line at Hoody end. Delayed clearance of fault observed from DR and PMU data.

GI-2

5 Tripping of 400kV Raichur TPS - Bellary TPS line

03-07-2019 at 4:39 hrs, 08-07-2019 at 5:20 hrs

Line tripped on operation of overvoltage stage-1 protection at Bellary TPS end and DT received at Raichur TPS end. From BTPS end. Difference in phase voltages observed from BTPS end DR (Vr-259kV, Vy-245kV and Vb-238kV)

GI-2

6 Tripping of 400kV BTPS-JSW line

08-07-2019 at 2:43hrs

Line tripped on operation of overvoltage stage-1 protection at Bellary TPS end and DT received at JSW. Difference in phase voltages observed at Bellary TPS from DR (Vr-241kV, Vy-257kV and Vb-225kV)

GI-2

7 Tripping of 220kV KTPS - Lower Sileru-1

08-07-2019 at 10:45 hrs

Line tripped on B-phase to earth fault. As per FIR, there was zone-2 operation at KTPS

GI-1

8 Tripping of 400kV Srisailam-Dindi line-2

11-07-2019 at 15:35 hrs

Line tripped on OV St-1 protection operation at Srisailam end and DT was received at Dindi end. From DR of Srisailam end,B phase voltage is observed to be higher than other two phases (Vr-243kV, Vy-244kV and Vb-253kV)

GI-2

9 Tripping of 400kV Nelamangala-Mysore line-2

15-07-2019 at 2:02 hrs

line tripped on operation of OV st-1 protection at Neelamangala end and DT was received at Mysore end. DR of Nelamangala end was not available for validation of OV protection operation

GI-2

10 Outage of Bus-2 at 400kV RYTPP station of APGENCO

18-07-2019 at 3:30 hrs

Bus bar protection of 400kV Bus-2 operated due to malfunctioning of CT supervisory circuit. All elements connected to Bus-2 tripped.

GI-2

11 Tripping of 400/110kV ICT-3&4 at S.V.Chatram S/s of TANTRANSCO

26-07-2019 at 14:07hrs

110kV Bus fault resulted in tripping of ICT-3&4

GI-2

12 Triping of 400KV/220KV JulurupaduICT-1&2

27-07-2019 at 2:31 hrs

ICT’s got tripped on operation of over flux protection

GI-2

Annexure-I


13 Tripping of 400/220 kV ICT-2 at Talaguppa

27-07-2019 at 16:27 hrs

ICT tripped due to mal-operation of OCR relay

GI-2

14 Tripping of 400kV Tippapur-Jangaon line-2

30-07-2019 at 12:23 ; 31-07-2019 at 19:00 hrs; 01-08-2019 at 21:58 hrs

Line tripped on operation of Over voltage stage-1 protection at Tippapur end and Direct trip received at Jangaon. As observed from DR of Tippapur R phase voltage was higher when compared to Y & B phases (Vr-253kV, Vy-231kV, Vb-239kV)

GI-2

15

Tripping of 400kV Krishnapatnam-Nellore line-1 and Unit -2 of Krishnapatnam

01-08-2019 at 21:49 hrs

Triggering incident was R phase to Y phase fault in the line. Unit -2 of SDSTPS also got tripped during the incident.

GI-2

16 Tripping of 400kV KTPS(VII)-Khammam line

01-08-2019 at 23:34hrs; 05-08-2019 at 1:07 hrs

Line tripped on operation of OV st-1 protection at KTPS end and DT receive at Khammam end. From DR of KTPS end, voltages observed are: Vr-249kV, Vy-244kV and Vb-244kV. R-phase voltage 5kV higher than Y & b phase voltage

GI-2

17 Tripping of 400kV Kalpakka-Vemagiri line-1

02-08-2019 at 07:06 hrs

Line tripped due to operation of LBB protection at Kalpaka end

GI-2

18 Tripping of 400/220kV Udumalpet ICT-3

04-08-2019 at 10:34 hrs

Udumalpet ICT-3 HV side and LV side CB tripped due to operation of Over-flux relay at LV side.

GI-2

19

Tripping of 400kV Simhadiri-Kalpakka line-1,2&3; 400kV Kalpakka-Asupaka line-1 & 400kV Kalpakka-Gazuwaka line-2

05-08-2019 at 13:37 hrs

Triggering incident was failure of R-phase LA in 400kV Kalpakka-Asupaka line.

GI-2

20 Tripping of 400kV Suryapet-Kethyreddipalli line-2

05-08-2019 at 21:15 hrs

Line tripped on operation of OV Stg-1 protection at Suryapet end and DT received at Kethyreddipalli. From DR of Suryapet Y phase is observed to be higher than R&B phase (Vr-238kV, Vy-253kV and Vb-241kV)

GI-2

21 400 kV Ramagundam – Hyderabad line-3

08-08-2019 at 3:50 hrs

Line tripped on operation of over voltage protection at Ramagundam. Direct trip was not received at Hyderabad and line was holding. Difference in R, Y and B phase voltage at Ramagundam was observed from DR (Vr-243kV, Vy-254kV, 239kV)

GI-2

22 Tripping of 400/110kV Kamuthi ICT-3

10-08-2019 at 11:00 hrs

ICT tripped due to operation of 110kV Bus bar protection

GI-2

23 Tripping of 400/220kV ICT-1,2,3&4 at N.P.Kunta

12-08-2019 at 12:08 hrs

ICT’s got tripped due to operation of 220kV Bus bar protection

GI-2

Annexure-I


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

Sl. No. Element Date & Time Reason

1 Tripping of 220kV Chilakallu-Suryapet line-1

11-07-2019 at 00:33hrs

R phase to Earth fault in the line. At Suryapet end, fault was detected in Zone-1 and at Chillakallu end, fault was detected in Zone-2. A/r not operated at both the ends

2 Tripping of Kaiga-Gutur line -2

22-07-2019 at 17:47hrs

Line tripped on B-phase to earth fault. Line did not auto-reclose.

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

Sl. No. Element Date & Time Reason

1 Tripping of 400kV Nellore-Sriperambadur line-2

01-07-2019 at 03:40 hrs; 28-07-2019 at 3:20 hrs

Direct trip received at both ends.

2 Tripping of 400kV Nizamabad-Dichipally line-2

25-07-2019 at 14:19 hrs

Line tripped on DT receive at Dichipally and line was holding from Nizamabad.

3 Tripping of 400kV Srisailam-Dindi line-2 and 400kV Satenapalli-Srisailam line-2

09-08-2019 at 05:00 hrs

400kV Srisailam-Dindi line-2 tripped on DT receive at Dindi and line was holding from Srisailam. 400kV Satenapalli-Srisailam line-2 on DT receive at both ends

Annexure-I

Meeting

No /

Index

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

Implementation

Status of Implementation of PCSC Recommendations Remarks Latest Status

(To be filled up by the Constituent)

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

Status of Pending Implementation of PCSC Recommendations as on 19.08.2019 (up to 85th Meeting)

KPTCL Mail dated 27-05-2015:

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

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

--- Pending

3. --- Pending

KPTCL Mail dated 29-07-2015:

1. Initial Tendering stage. --- Pending

2. --- Pending

3. --- Pending

KPTCL Mail dated on 23-01-2016:

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

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

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

3. --- Pending

PGCIL (SR-I) Mail dated 14.07.2016:

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

Commettee recomendations and implemented" --- Completed.

KPTCL Mail dated 16.12.2017:

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

Review Meeting dated 19.12.2017:

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

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

is targeted by January, 2019

--- Pending

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

Completed.

KPTCL mail dated 19.12.2018:

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

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


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

16-07-201434/I/6 400/220 kV ICT-1 & 2 at

Munirabad

As reported directional over current relay of ICT’s

operated due to snapping of line jumper in 220kV

Lingapur line.

1. Bus bar protection shall be provided by asset

owner ( i.e KPTCL).

2. Settings for main distance protection &

Overcurrent protection shall be examined and

reviewed.

3. Time synchronization of the Substation shall be

ensured.

KPTCL/

PGCIL (SR-I)

Pending

(with KPTCL)

Multi-Utilities

Complete outage of TPCIL

power station

PendingPGCIL (SR-I),

MEPL, SEL, TPCIL,

NCC

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

30-12-2015 at

06:02hrs

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

findings of OEM on relay mal-operation at NPS end

on 400 kV NPS – NCC line to PCSC forum.

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

Event Logger at NPS to record events at msec interval.

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

in coordination with TPCIL for 400 kV NPS –TPCIL

line.

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

steps to provide line differential protection at their

respective ends on all 400 kV lines (except Gooty line)

emanating from Nellore Pooling Station, and furnish

an action plan to implement the same.

Annexure-II

Page 1 of 48


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

PGCIL (SR-I) mail dated 20.06.2018:

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

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

week.


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

completed by Jan'2019 and commissioning by Mar'19.


4. PGCIL-SR1: LDP relays (Main-1) commissioned in 400kV NPS-TPCIL-1 Line

during opportunity shutdown. NPS-NCC D/C & NPS-TPCIl D/C lines LDP relay

retrofitting planned in June & July -2019.

In 154th OCC meeting SRLDC/SRPC has advised to re-schedule LDP

commissioning tentatively to Sep/Oct’2019.

Complete outage of TPCIL

power station

PendingPGCIL (SR-I),

MEPL, SEL, TPCIL,

NCC

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

30-12-2015 at

06:02hrs

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

findings of OEM on relay mal-operation at NPS end

on 400 kV NPS – NCC line to PCSC forum.

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

Event Logger at NPS to record events at msec interval.

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

in coordination with TPCIL for 400 kV NPS –TPCIL

line.

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

steps to provide line differential protection at their

respective ends on all 400 kV lines (except Gooty line)

emanating from Nellore Pooling Station, and furnish

an action plan to implement the same.

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

APTRANSCO mail dated on 20-12-2016:

Issue was addressed to the concerned for necessary action.

APTRANSCO mail dated on 24-05-2017:

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

progress.

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

Relays procurement for all the locations is under progress.

APTRANSCO Mail dated 15.12.2017:

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

next week.


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



complete the work by FEbruary, 2018.





asked all stakeholders to ensure & comply with the same.

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

Pending

Annexure-II

Page 2 of 48

APTRANSCO Mail Dated 24.04.2018:

ABB make LDP relays inspection is completed. SNEIDER make LDP relays

inspection yet to be completed. Delivery of relays expected in the 1st weak of May-

2018.


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

expected in the month of june 2018.


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


week.


ABB make LDP relays are delivered. Schneider make LDP relays inspection to be

offered by the company.

APTRANSCO Mail Dated 25.07.2018:APTRANSCO Mail Dated 25.09.2018:

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

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


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

in coordination with the Alstom (Area) engineers who implemented SAS.


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

relays will be completed by Jan'2019 and commissioning by Mar'19

APTRANSCO MAIL DATED 22.01.2019:

The relays are yet to be commissioned.

APTRANSCO mail dated 15.03.2019:

Commissioning of LDP relays scheduled in the month of April 2019.


Schnider make P546 LDP relays commissioned in place of Main-1 relays at Nellore

end for 400KV Krishnapatnam feeder on 26/03/19 and for feeder-2 on 27/03/19.

ABB make RED670 relays yet to be commissined in place of Main-2 relays.


PGCIL-SR1: LDP relays (Main-1) commissioned in 400kV NPS-TPCIL-1 Line

during opportunity shutdown. NPS-NCC D/C & NPS-TPCIl D/C lines LDP relay

retrofitting planned in June & July -2019.

In 154th OCC meeting SRLDC/SRPC has advised to re-schedule LDP

commissioning tentatively to Sep/Oct’2019.


ABB make RED670 relays testing is under process and will be commissioned in

place of Main-2 relays for Krishnapatnam-1&2 feeders by 30.06.2019 at 400KV

Manubolu SS.


ABB make RED670 type LDP relays commissioned in place of Main-2 relays at

Nellore end for 400KV Krishnapatnam feeder-1 on 17/07/19 and for feeder-2 on

15/07/19. The 400KV Krishanapatnam line-2 main-2 relay is in service in

Differential mode. But due to non availability of suitable patch cards, Main-1 of KP-

1 & Main-1&2 of KP-2 feeders are not in differential mode but in Distance mode.

The diffential mode of operation will be kept in service by after purchasing suitable

patch cards.





MEPL line

18-07-2016

at 19:05 hrs






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

Pending

Annexure-II

Page 3 of 48

NTPC mail dated 07.12.2017:

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

2. ---- Pending


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

completed in 3 months time.

TSTRANSCO MAIL DATED 20.01.2018:

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

2018.


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

of May, 2018.


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

and erection will be completed by end of June, 2018.


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

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


Relays will be commissioned by end of February, 2019.


Replacement of porcelain insulators with Polymer insulator for 4 Km radius ( in

Chennai area) from NCTPS.2 in 400kV SVCM & Alamathy feeders were completed.

TSTRANSCO mail dated 22.06.2019:

2. Relay erection work is under progress and will be completed by end of July, 2019.

NTPC-Ramagundam/

TSTRANSCO

Pending66/ 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.

Annexure-II

Page 4 of 48

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



complete the work by February, 2018.





asked all stakeholders to ensure & comply with the same.


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


week.


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

completed by Jan'2019 and commissioning by Mar'19.

Review Meeting on 20.12.2018 & 27.06.2019:

Pending

APTRANSCO maild ated 30.01.2018:

1. Pending...

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

APTRANSCO maild ated 24.04.2018 & 24.05.2018 & 26.06.2018:

1. Pending...

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

PGCIL. Ii) PD relay event is configured in the EL as per the recommendation.


1. ---Pending

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

relay contact. ---Completed


1) Bays and lines pertains to PGCIL .

2) ---Completed.


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

completed by Jan'2019.


Pending [with PGCIL (SR-I)]


PGCIL(SR-1):

This issue of retrofitiing of distance relays with LDP relays in Kurnool(PG) –

Kurnool(AP) D/C lines has been discussed with our management. Our management is

seeking approval for the same. You are requested to takeup this LDP issue in next

TCC meeting.

Tripping of 400 kV

Kurnool(PG) – Kurnool(AP)

line-2

Pending [with

PGCIL (SR-I)]

APTRANSCO/

PGCIL (SR-I)

69/III/3 02-10-2017 at

02:03 hrs

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

Line Differential Protection as both the Main

protections on 400 kV Kurnool (AP) – Kurnool (PG)

lines 1 & 2 lines.

2) APTRANSCO to furnish an action taken report

w.r.t. resolving A/R non-operation at Kurnool-AP end

for the subject trippings and configure EL for capturing

PDR operation at their 400 kV Kurnool-AP SS.

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

unsuccessful at both Kurnool (AP) and Kurnool (PG)

ends.

Annexure-II

Page 5 of 48

APTRANSCO maild ated 15.12.2017:

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

proposed by KPTCL.


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

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

Ragulapadu - Alipira section only. When enquired about the same, KPTCL informed

that they would examine the issue in detail, and would inform the action lan proposed

by next PCSC-71 meeting. On this, APTRANSCO was also asked to render all help

required from their side to KPTCL.

APTRANSCO maild dated 30.01.2018:

APTransco world extend required support .

APTRANSCO maild dated 24.04.2018 & 24.05.2018 & 26.06.2018:

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

ragulapadu-Alipura line by KPTCL.


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


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

Review Meeting on 20.12.2018:

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

KPTCL alongwith APTRANSCO.


Pending [with KPTCL ]


KPTCL informed that the work is expected to be completed by August 2019.

1) TANTRANSCO to provide double-bus operation at

their 230 kV Thiruvalam SS.

2) APTRANSCO to replace the existing static relays

with suitable numerical relays for various line

protections at their 220 kV Chittoor SS.

Pending

[with KPTCL ]

Tripping of 230 kV

Thiruvalam - Chittoor line

76/II/9 1) TANTRANSCO Mail dated 29.08.2018 & 11.09.2018:

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

2) APTRANSCO Mail dated 24.09.2018:

The static relays were replaced with Numerical relay on all 220 kV feeders at 220 kV

SS chittoor.---Completed

TANTRANSCO Mail dated 11.12.2018:

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


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

prvodie double-bus operation at their 230 kV Tiruvalam SS.


Pending [with TANTRANSCO]

TANTRANSCO MAIL DATED 23.01.2019 & 19.03.2019:

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

will be taken. Time upto Sep 2019

TANTRANSCO MAIL DATED 13.06.2019:

1. Bus segregation will be ensured by providing bus coupler bay by extending the

existing Bus.Time line 31.12.2019.

TANTRANSCO mail dated 18.07.2019 & 26.07.2019:

1. Bus segregation will be ensured by providing bus coupler bay by extending the


Pending [with

TANTRANSCO]

TANTRANSCO/

APTRANSCO

13-06-2018 at

18:55hrs

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

Tiruvalam end, breaker was under lockout leading to

operation of LBB protection.

69/III/7 Tripping of 220 kV

Ragulapadu – Alipura line

12-10-2017 at

01:30 hrs

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

at Regulapadu and breakers at Alipura end got tripped.

Annexure-II

Page 6 of 48


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

1.--- Pending

2. --- Pending


1. & 3. Completed

2. Pending

KPCL mail dated 24-12-2018:

1) --- Completed

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

version Numerical Line protection relays having IEC61850 shortly, after availing

necessary admnistrative approval...Pending

3) Completed

KPCL mail dated 23.01.2019:

1. Completed

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

distance relays.KPCL mail dated 23.03.2019:

1). COMPLETED


version Numerical Line protection relays having IEC61850. Prepration of

specification is under progress.

3) COMPLETED


1) & 3) Completed

2) Budgetary offer obtained for replacement of existing PZ1000 relays with new

version Numerical Line protection relays having IEC61850. Preparation of estimation

and specification is under progress.


1) & 3) Completed

2) Replacement of existing PZ1000 relays with new version Numerical Line

protection relays having IEC61850 is included in PSDF Phase-II DPR. Approval of

NLDC for DPR is awaited. Further, availing administrative approval for issue of NIT

for replacement of existing PZ1000 relays with new version Numerical Line

protection relays having IEC61850 and preparation of estimation and specification is

under progress.

Review Meeting on 27.06.2019:KPCL mail dated 16.07.2019:

1) & 3) Completed



NLDC for DPR is awaited. However, administrative approval for issue of NIT for

replacement of existing PZ1000 relays with new version Numerical Line protection

relays having IEC61850 obtained. Preparation of technical specification is under

progress.

17-09-2018 at

14:37hrs

Complete outage of 220 kV

Nagjheri PH and 220/110 kV

Ambewadi Substation.

78/I/2 PendingKPCL/ KPTCL1. SLDC/KPTCL to be pro-active in issuing necessary

directions that help in expeditious restoration of the

tripped lines based on the prevailing conditions and

grid security.

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

emanating from their 220 kV Nagjheri PH, with the

help of KPTCL, by December, 2018. In the event of

non-amenability of the existing PZ1000 relays in

providing A/R feature, KPCL shall take steps to

retrofit them with suitable relays that support A/R.

3. KPTCL to restore PLCC carrier communication on

220 kV Nagjheri – Bidnal line at the earliest

220kV lines connected to Nagjheri PH got tripped due

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

at Nagjheri got tripped on over frequency protection

operation due to loss of evacuating lines resulting in

complete outage of 220 kV Nagjheri. 220 kV Nagjheri

being the only source to 220kV Ambewadi station,

since 220kV Ambewadi Narendra line 1&2 were under

shutdown during antecedent condition, tripping of

Units at 220 kV Nagjheri resulted in the loss of supply

to 220 kV Ambewadi SS.

Annexure-II

Page 7 of 48


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

time --- Pending

KPCL mail dated 24-12-2018:

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

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

malopration --- Completed.


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

2)....Completed.


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

KPCL mail dated 10.05.2019 & 25.06.2019:

1) Letter addressed to KPTCL RT dated: 25.03.2019 for review and implementation

of SPS at NPH. Reply is awaited.


1. KPTCL informed that Nagjheri SPS has to be studied in the event of configuration

changes and outcome of the same will be intimated soon .KPCL mail dated 16.07.2019:


of SPS at NPH. Reply from KPTCL is awaited.

2)Completed.

TANTRANSCO Mail dated 11.12.2018:

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

feedback. Work under progress. ......Pending

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

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

3.......Pending


Relays settings reviewed and need to be revised due to change of line length DR &

EL's of Main-1 (P444) relay configured properly. Main-2 (D60) relay to be

configured.


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

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


Collecting the details of adjacent feeders connected to Gummadipudi for computing

revised relay settings.


Isolator status will be ensured by March 2019

TANTRANSCO/

APTRANSCO

05-10-2018 at

00:42 hrs

Complete outage of 230/ 110

kV Gummidipoondi

Substation

78/II/16

1) TANTRANSCO to take steps to implement multi-

bus, multi-zone operation (Double-bus operation) at

their 230 kV Gummidipooindi SS by December,

22018.

2) TANTRANSCO to check if the Gummidipoondi

substation is adequately protected from lightning-

strokes by providing requisite no. of lightning masts

and/ or earth-wire caging.

3) APTRANSCO was asked to verify & correct the

settings employed for distance protection at Sullurpeta

and configure DR’s & EL’s of all Protection Relays at

their Supllurpet SS properly for recording only the

mandated protections & digital signals.

Pending [with

TANTRANSCO]

KPTCL/ KPCL1)KPTCL to examine the reasons for tripping of more

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

Nagjheri PH during subject trippings, and furnish a

report on the same along with remedial action taken to

PCSC forum.

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

msec in operation of REF protection for the GT of Unit-

2 at their Nagjheri PH.

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

Ambewadi line-1. As per the information received,

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

220 kV Naghjeri Ambewadi line#2 got overloaded.

This resulted in the tripping of Nagjheri Generating

Units #3 and 6 on SPS operation. At the same time,

Unit #2 got tripped on REF operation.

PendingMultiple trippings at 220kV

Nagjheri PH

Triggering incident was B-phase fault at 230kV

Gummidipoondi Substation due to which 230kV Bus-1

Bus-bar protection operated. 230kV Gummidipoondi

Station was under single bus operation, hence

operation of Bus-bar protection resulted in tripping of

all connected elements.

31-08-2018

at 11:49 hrs

79/I/2

Annexure-II

Page 8 of 48


3. Revised relay settings were implemented on 16/02/2019 ---Completed


New 230kV isolators have been allotted for replacement of defective isolators. Hence

time line requested upto June.2019.


1. New 230kV isolators have been allotted for replacement of defective isolators.

Hence time line requested upto Sep.2019.


1. New 230kV isolators have been allotted for replacement of defective isolators.

Hence time line requested upto Sep.2019.

2. & 3. Completed

TANTRANSCO mail dated 18.07.2019 & 26.07.2019:

1. 1New 230kV isolators have been allotted for replacement of defective isolators.

Hence time line requested upto Sep.2019

81/IV/3 Tripping of 400 kV

Warangal - Bhoopalapalli

line-2

15-12-2018 at

20:42 hrs

Line tripped at Bhoopalapalli end only and was holding

from warangal s/s. FIR, DR and EL of Bhoopalapally

were not furnished.

For the line under consideration, the following shall be

carried out by TSGENCO in coordination with PGCIL

(SR-I):

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

other signals may be ensured by testing at both the

ends.

(ii) Healthiness of PLCC system components

(hardware and software) at both ends shall be checked

and faulty components shall be repaired/ replaced.

TSGENCO/ PGCIL (SR-

I)


PGCIL-SR1: Presently WGL-Bhopalapalli-2 line PLCC Ch-1 is unhealthy same was

informed to TSGENCO for rectification. The Ch-1 is out of service from last 50 days

onwards. Both ends PLCC belongs to TSGENCO

TSGENCO mail dated 24.06.2019:

TSGENCO is cordinating with TSTRANSCO for testing of End-to-End

communication for DT/permissive & other signals; checking of Healthiness of PLCC

system components and also for replacing of faulty components .


TSGENCO informed that PLCC has to be replaced and will be done by December

2019.

Pending [with

TSGENCO]


Veeranam substation of

TANTRANSCO

11-03-2019

at 00:55Hrs

Triggering incident was Y-phase CT blast in 230kV

Tirunelvelli (Abhishekpatty) – Veeranam Ckt-1.

230kV Trirunelvelli – Veeranam Ckt-1 and 2 tripped.

Two faults were observed from the PMU plot. During

the second fault, delayed fault clearance of 400ms was

observed. As reported, other connected feeders 230kV

Veeranam – Kodikur ckt-1&2 and 230kV Veeranam –

Kayathar tripped on Zone -2 protection.

1. TANTRANSCO is recommended to submit action

plan to provide Multi-Bus operation/ Hybrid breakers

at 230kV Veeranam SS with clear timelines.

2. TANTRANSCO to revise the distance zone settings

at Tiruneveli SS for 230kV Veeranam – Tirunelveli

line to overcome the problem of relay overreach and

share the same with SRPC.

3. TANTRANSCO to take definite measures ensure

the time synchronization of relays at Tirunelveli end.

4. TANTRANSCO to submit equipment failure report

of the failed CT to CEA.

TANTRANSCO TANTRANSCO MAIL DATED 13.06.2019:

1.Provision of bus coupler breaker is not feasible due to space constaint.

2&3. Tirunelveli end maintained by PGCIL.

4. Report will be sent.

Review meeting on 27.06.2019:


2. Will be informed

3. Time synchronisation will be ensured.

4. Report will be sent.

TANTRANSCO mail dated 19.07.2019:


2&3. Tirunelveli end maintained by PGCIL.

4. Report sent to CEA.

Pending[PGCIL-

SR-II]

TANTRANSCO/

APTRANSCO

05-10-2018 at

00:42 hrs

Complete outage of 230/ 110

kV Gummidipoondi

Substation

1) TANTRANSCO to take steps to implement multi-

bus, multi-zone operation (Double-bus operation) at

their 230 kV Gummidipooindi SS by December,

22018.

2) TANTRANSCO to check if the Gummidipoondi

substation is adequately protected from lightning-

strokes by providing requisite no. of lightning masts

and/ or earth-wire caging.

3) APTRANSCO was asked to verify & correct the

settings employed for distance protection at Sullurpeta

and configure DR’s & EL’s of all Protection Relays at

their Supllurpet SS properly for recording only the

mandated protections & digital signals.

Pending [with

TANTRANSCO]

Triggering incident was B-phase fault at 230kV

Gummidipoondi Substation due to which 230kV Bus-1

Bus-bar protection operated. 230kV Gummidipoondi

Station was under single bus operation, hence

operation of Bus-bar protection resulted in tripping of

all connected elements.

79/I/2

Annexure-II

Page 9 of 48


Hubli substation of KPTCL

and 220kV

Nagjheri Power station of

KPCL

10-04-2019

at 18:09Hrs

Y and B-phase earth isolator switch blades of 220kV

Hubli-Bidnal ckt-1, got closed due to failure of locking

mechanism during heavy wind and rain

conditionsresulting in bus fault. Bus bar protection

operated and all connected elements tripped. There was

complete loss of supply at 220kV Hubli station since

the station was on single bus operation. At thesame

time, 220kV Nagjheri-Ambewadi ckt-1 and 220kV

Nagjheri – Bidnal tripped on overcurrent

protection. Since 220kV Nagjheri – Ambewadi ckt-2

and 220kV Nagjheri-Kodasalli ckt-1 &2 wereunder

shutdown in the antecedent due to maintenance,

running units #1,4,5 and 6 tripped due to

loss of evacuating lines. This resulted in complete loss

of supply at 220kv Nagjheri station.

1. KPTCL is recommended to revise the SPS at

Nagjheri, (to accommodate a new condition with high

flow and low time delay) in consultation with SRPC

and SRLDC.

2. KPCL in coordination with KPTCL is recommended

to provide at least one main protection as carrier aided

three zone distance protection on the 220kV lines

emanating from Nagjheri GS.

KPTCL/ KPCL KPCL mail dated 25.06.2019:

2) Carrier aided protection is enabled on all 220kV lines emanating from NPH

___Completed


1. KPTCL informed that Nagjheri SPS has to be studied in the event of configuration

changes and outcome of the same will be intimated soon


1. under progress

2. Completed

Pending

83/II/9 Tripping of 400 kV

GUTTUR - NARENDRA -1

10-03-2019 at

18:03hrs

Line tripped on operation of overvoltage stage-1

protection at Guttur end and DT received at Narendra

end. Voltages at Guttur end: Vr-254kV, Vy-252kV,

Vb-246kV. As per voltage grading, 400kV Guttur

Narendra line-2 should trip first.

PGCIL (SR-II) to submit action plan regarding

replacement of CT’s for 400Kv Guttur Narendra line -

1 at Guttur end. PGCIL (SR-II) to sort out the time

sync issues in DR and EL at Narendra end.

PGCIL (SR-II)/ KPTCL PGCIL (SR-I) mail dated 07.06.2019:

Line belongs to PGCIL(SR-2)


PGCIL(SR-II) informed that R & Y ph CVT replaced on 25.05.2019. Time

syncronisation has to be attended by KPTCL.

Pending

23-03-2019 at

04:41 hrs

24-03-2019 at

02:32 hrs

25-03-2019 at

01:19 hrs


NCTPS Generating Station

of TANGEDCO

18-05-2019 at

04:39 hr.

Triggering incident was Y phase to Earth fault in 220

kV NCTPS Tondiarpet line-2. Due to mal-operation of

LBB protection (of Tondiarpet line-2) at NCTPS end,

all the connected elements of bus zone-3 got tripped.

Due to loss of evacuating lines, running units at

NCTPS unit#1 and 2 got tripped.

1.TANTRANSCO may take immediate measures to

attend the problem in LBB wiring that is extending trip

during A/R within one month.

2. TANTRANSCO is recommended to send a detailed

report regarding the A/R status (availability

/enabling)on all lines emanating from 230kV NCTPS

GS and enable A/R in all lines emanating from 230kV

NCTPS GS.

3.TANGEDCO in coordination with TANTRANSCO

may take definite measures to ensure time

synchronization of all relays with GPS signal at

NCTPS end and remote ends at the earliest.

4. It was also suggested that possibility of backing

down of generation, in the event of unavailability of

many feeders, in particular when radial feeders only

are in service, may be looked at.

TANGEDCO/

TANTRANSCO


1 & 2.Inbuilt LBB function will be enabled in the new distance relays.

3. will be ensured.

4.230kV Kilpauk was operated radially for avoid overloading in the adjacent feeders

due to cable fault in the area.Normally all feeders are operated as grid feeders.

Pending

APGENCO/

APTRANSCO


3. Line Insulator stacks were replaced with SRC insulators at location Nos.4,5,6 for

Krishanpatnam-1 on 26/03/2019 and Krishanpatnam-2 on 27/03/2019.--------------

Completed.


1. APGENCO representative did not attend the meeting. APGENCO is requested to

furnish the status at the earliest.

83/II/17 Pending [ with

APGENCO]

Tripping of 400kV

Krishnapatnam – Nellore ckt-

1

Feeder tripped due to severe tracking on line insulator

stacks.

1. APGENCO to inform PCSC forum the following:

Status of A/R in 400kV Krishnapattnam – Nellore

line-1 at Krishnapattanam end, if A/R is not enabled

APGENCO shall implement 1-ph ‘lead-follow’ A/R

scheme at Krishnapattanam.

The reason for tripping of Unit-2, along with the line

tripping on 24.03.2019.

2. APGENCO in consultation with APTRANSCO to

explore the possibility of providing Line Differential

Protection (LDP) for the line.

3. APTRANSCO is recommended to replace the

insulators of the line with polymer insulators.

Annexure-II

Page 10 of 48


NCTPS Generating Station

of TANGEDCO

19-05-2019 at

22:44 hr.

230kV lines connected to NCTPS got tripped due to

fault in lines. Running units#1,2 and 3 at 230kV

NCTPS also got tripped due to loss of evacuating lines.

1. TANGEDCO in coordination with TANTRANSCO

to take definite measures to ensure time

synchronization of all relays with GPS signal at

NCTPS end and remote ends at the earliest.

2.The PCSC noted frequent jumper cut/conductor snap

instances in the area, of late; accordingly, it was

suggested to have adequate condition monitoring and

preventive maintenance measures.

3.TANTRANSCO to communicate

(i) the schedule of replacement of balance porcelain

insulators with polymer insulators in evacuation lines

from NCTPS.

(ii) schedule of insulator washing

4.NCTPS /TANGEDCO to inform regarding house

load operation capability of Generators at NCTPS.

TANGEDCO/

TANTRANSCO


2& 3.wedge connector have been provided in order to avoid jumbercut.

4. Replacement of porcelain insulators by polymer insulatos in all 230kV & 400kV

feeders in North Chennai area has been completed

Pending

84/II/4 Tripping of 230kV Sulurupet-

Gumudipoondi line

11-04-2019 at

16:05 hr.

Triggering incident was B-N fault in 230kV

Gummudipoondi-NCTPS line. 230kV Sulurupet -

Gummudipoondi line tripped on operation of zone-2

distance protection at Sulurpet end and reverse zone

protection at Gummudipoondi end.

1.TANTRANSCO to check the resistive and reactive

reach settings of 230kV Gummudipoondi-NCTPS line

at Gummidipoondi end.

2. APTRANSCO to ensure time synchronization of

DR and EL at Sulurupet end. Also in coordination with

TANTRANSCO sort out the time synchronization

issue in 230kV Sulurupet-Gumudipoondi line.

3. TANTRANSCO to check the SOTF settings at

Gummidipoondi end for 230kV Gummudipoondi-

NCTPS line .

TANTRANSCO/

APTRANSCO


2. GPS not available at 220KV Sullurpet SS.Manually set the timing on 29/07/2019 -

- Completed


1. & 3. Will be reviewed

Pending [ with

TANTRANSCO]

84/II/19 Tripping of 400/220 kV ICT-

1 atCuddapah

03-05-2019 at

23:39 hr.

ICT-1 Tripped on operation of APTRANSCO 220 kV

Bus Bar relay (96 trip relay). Fault reported in 220 kV

Cudappah-Renigunta line

1. PGCIL (SR-I) to submit the high set settings of

ICT’s at Cuddapah. Since the static relay in which

high set is enabled has no provision to provide time

delay, ICT high set shall be enabled from numeric

relay and sufficient time delay shall be provided for

highset operation.

2.APTRANSCO to check the Busbar operation at 220

kV Cuddapah SS and submit a report regarding the

same.

3. PGCIl (SR-I) to inform the methodology adopted for

calculating high set settings of ICT’s. Also due to

changes in system configuration at Cuddapah in recent

future revision of set points shall be taken up.

PGCIL (SR-I)/

APTRANSCO


2. The 220KV GE make B90 type Bus Bar relays tested on 23/07/19 and found

healthy. The report submitted vide mail dated 29.07.2019 - Completed

Pending [ with

PGCIL (Sr-1)

84/II/22 Tripping of 400kV

Khammam-Mamidapalli line-

1

09-05-2019 at

02:40 hr.

Line tripped on mal-operation of Reactor differential

protection and DT sent to Khammam.

TSTRANSCO in coordination with PGCIL (SR-I) to

ensure time synchronization of relays at Mamidapalli

end with Khammam end in 6 months’ time.

TSTRANSCO/ PGCIL

(SR-I)

Yet to be informed Pending

Annexure-II

Page 11 of 48

84/II/29 Frequent tripping of 220 kV

KTPS –Lower Sileru line

01-05-2019 at

16:04 hr.

04-05-2019 at

14:48 hr.

05-05-2019 at

11:29 hr.

06-05-2019 at

13:14 hr.

09-05-2019

at13:58 hr.

12-05-2019

at11:10 hr.

15-05-2019

at21:05 hr.

26-05-2019

at15:36 hr.

29-05-2019

at21:26 hr.

B-N FAULT

B-N FAULT

B-N FAULT

B-N FAULT

R-N FAULT

R-B FAULT

R-B FAULT

B-N FAULT

R-B FAULT

It was noted that no representative of APGENCO

attended the meeting.

For the subject line, the following shall be carried out

by TSGENCO in co-ordination with APGENCO:

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

other signals may be ensured by testing at boththe

ends.

(ii) Healthiness of PLCC system components

(hardware and software) at both ends shall be checked

and faulty components shall be repaired/ replaced.

APGENCO in coordination with TSGENCO to

ensure frequent patrolling and proper maintenance of

ROW by attending all tree clearance issues.

APGENCO/

TSGENCO


85/II/3 Tripping of 400kV Kurnool-

Srisailam line

17-05-2019 at

14:10 hrs

line tripped only at Srisailam end on Zone-3 distance

protection operation during Y phase to B phase fault in

220kV NarnoorSomayajulapalli line-1

1. TSGENCO is recommended to modify the PSL

logic (Srisailam end to trip for faults occurring in Zone-

2 and Zone-3 with respective time delays except for

PUR scheme if adopted ) in 1 month time to avoid

occurrence of any such unwarranted trippings in future.

2. APTRANSCO to ensure time synchronization of

relays at 220kV Somayajulapalli SS.

TSGENCO/

APTRANSCO


85/II/14 Tripping of 230kV Theni-

Sabarigiri line

29-05-2019 at

18:39 hrs

3 phase to earth fault occurred in line. Tripped on

ground over current protection 67N at Sabarigiri and

Zone-2 at Theni end.


by TANTRANSCO in coordination with KSEBL:

(i) End-to-end testing 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 the ends shall be

checked and faulty components shall be repaired/

replaced .

TANTRANSCO/

KSEBL


85/II/17 400 kV Ghani – Narnoor line-

1, 400 KV Jamalamadugu-

Kurnool line-1, 765/400 kV

ICT-1&2 at Kurnool

30-05-2019 at

00:48 hrs

Triggering incident was Y-ph to B-ph fault in the

400kV NarnoorJammalamadugu line-1 & 2 due to

falling of Y-ph CVT jumper on B-ph during heavy

wind. At the same time, 400kV GhaniNarnoor tripped

only at Ghani end on operation of Zone-1 distance

protection. 765/400 kV ICT-1 & 2 at Kurnool PG also

got tripped on HV side Directional Overcurrent (DOC)

protection.

1. APTRANSCO is recommended to sort out the issues

with their distance protection relay (7SA522) which

maloperated and caused unwarranted tripping of

400kV Ghani – Narnoor line-1. The time

synchronization of relays at Ghani end also shall be

ensured.

2.PGCIL (Sr-1) is recommended to submit a detailed

report regarding operation of ICT Buchholz relay for

through fault conditions along-with remedial measures

suggested by OEM.

APTRANSCO/ PGCIL

(SR-1)


85/II/20 Tripping of 220kV Idukki-

Udumalpet line

05-06-2019 at

15:13 hrs

Triggering incident was R-Y-Earth fault in the

line. Carrier aided protection not operated at

Udumalpet end.


by TANTRANSCO in coordination with KSEBL:

(iii) End-to-end testing for DT/ permissive & other


(iv) Healthiness of PLCC system components (



replaced .

KSEBL/

TANTRANSCO


85/II/26 Tripping of 400kV Vemagiri-

GMR line-1&2

14-06-2019 at

09:33 hrs

Line-1 tripped on Y-Phase to earth fault due to Y-

Phase LA failure at Vemagiri end. Line-2 tripped at

GMR end only

1. APTRANSCO is recommended to submit

Equipment failure report (LA failure) to CEA.

2.GMR is recommended to submit a report regarding

tripping of 400kV Vemagiri-GMR line-2 at GMR end

along-with the related tripping files.

APTRANSCO/ GMR Yet to be informed Pending

Annexure-II

Page 12 of 48

02-06-2019

at 15:30 hrs

R-phase to earth fault occurred in line. Auto-reclose

was successful at Lower sileru end. A/r is not enabled

at KTPS.

02-06-2019 at

15:30 hrs


was successful at Lower sileru end. A/r is not enabled

at KTPS.

09-06-2019 at

11:58 hrs

B-phase to earth fault occurred in line. Zone-2

operated at KTPS and Earth fault at Lower sileru.

Suspected high resistance fault.

12-06-2019 at

14:23 hrs

Y-phase to earth fault occurred in line. Auto-reclose

was successful at Lower Sileru end. A/r is not enabled

at KTPS

85/IV/2 Tripping of 400kV

Khammam-Mamidapally line-

1

27-05-2019 at

18:16 hrs

Line tripped only at Mamidapally end due to suspected

PLCC maloperation


by TSTRANSCO in coordination with PGCIL(SR-I):

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


(ii)Healthiness of PLCC system components (



replaced .

TSTRANSCO/ PGCIL

(SR-I)


85/IV/5 Tripping of 400kV Warangal-

Bhoopalapalli line-1

&BoopalppalliChandlapur

line-1

08-06-2019 at

1:35 hrs

400kV Warangal-Bhoopalapalli line-1 line tripped

only at Boopalappalli end on OV st-1 protection

operation and DT was not sent to Warangal end due to

failure of both PLCC channels. 400kV

BoopalppalliChandlapur line-1 tripped at Boopalpalli

end due to DT Receive


by TSTRANSCO in coordination with TSGENCO

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


(ii)Healthiness of PLCC system components (



replaced .

TSGENCO/

TSTRANSCO


ATRANSCO in coordination with TSTRANSCO to

ensure frequent patrolling and proper maintenance of

ROW by attending all tree clearance issues.

APTRANSCO/

TSTRANSCO

Yet to be informed Pending85/II/32

Andhra Pradesh

220kV Lower Sileru-KTPS

line

Annexure-II

Page 13 of 48





MEPL line

18-07-2016

at 19:05 hrs






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

82/III/8 Tripping of 400kV VTPS-

SURYAPET-1

10-02-2019

at 13:20 hrs

B-phase to earth fault occurred in line. Auto-reclose

was successful at Suryapet and breakers got tripped at

VTPS end


attended PCSC-82 meeting. APGENCO to furnish a

detailed report on tripping event bringing out reasons

for A/R non-operation at VTPS end along with

remedial action taken to PCSC forum.

APGENCO Review Meeting on 27.06.2019:



Pending

82/III/9 Tripping of 400kV VTPS-

SURYAPET-1

15-02-2019

at 14:36 hrs


was successful at Suryapet and breakers got tripped at

VTPS end


attended PCSC-82 meeting. APGENCO to furnish a

detailed report on tripping event bringing out reasons

for A/R non-operation at VTPS end along with





Pending

83/II/20 Tripping of 220kV VTS-

Talapalli ckt-3 and

Generating Units#1,2,3,4,5

& 6 at VTS.

01-04-2019 at

22:58hrs

220kV VTS – Talapalli ckt-4 was under maintenance.

While restoring the feeder, 220kV VTS – Talapalli ckt-

3 tripped on Zone-1 distance protection due to B-N

fault. At the same tine VTS unit# 1 & 2 tripped on

Loss of fuel and Generators 3,4,5&6 tripped on

Generator Negative phase sequence protection.

1. APGENCO is recommended to revise the time

delay of Negative Phase sequence protection operation

in consultation with OEM.

2. APGENCO is also recommended to look into the

Overcurrent Protection settings of Buscoupler, so as to

reduce its time delay of operation in case of faults on

Transfer Bus.




Pending

83/III/8 Tripping of 400 kV VTPS -

Nellore

24-03-2019 at

12:46hrs

Feeder tripped on Y -N Fault. Auto reclose operated at

Nellore end but not operated at VTPS end.

APGENCO is recommended to submit a detailed

report regarding the reason for A/R being kept

disabled and the Remedial Measure taken for the same.




Pending

84/II/9 Tripping of 220kV Bus 2 and

connected elements at 220kV

Gazuawaka Substation.

17-04-2019 at 5:40 hr.Triggering incident was Y-phase to earth fault in

220kV Gazuwaka Bus-2. This resulted in tripping of

220 kV elements and 400/220 kV ICT-2

1. APTRANSCO to submit a detailed report

regarding the subject tripping at 220 kV Gazuawaka

Substation along with the remedial measures taken.

2. For all lines emanating from Gazuwaka SS, RTV

coating shall be taken up.

APTRANSCO APTRANSCO mail dated 30.07.2019:

1. The report submitted vide mail dated 29.07.2019 -- Completed

2. Pending

Pending


2 at Ghani substation

21-05-2019 at

15:13 hrs

ICT-2 tripped on LV Earth fault protection. 400kV

Ghani-Narnoor line-1 had tripped on B-phase to earth

fault.

APTRANSCO is recommended to send a detailed

report regarding non-availability of Main CB (Main

CB was already in tripped condition in antecedent

condition) during the tripping and non-attempt of auto-

reclosure by Tie CB at Ghani end.

APTRANSCO Yet to be informed Pending

85/II/27 Multiple tripping at 220kV

Nunna substation

16-06-2019 at

06:16 hrs

Triggering incident was failure R phase CT of

220/132kV transformer (connected to 220kV Bus-2) in

220kV Nunna station. Bus-2 bus bar protection

operated resulting in tripping of elements connected to

220kV Bus-2. 2.63 Seconds later a 2nd fault occurred

in Bus-1 due to fault getting extended from Bus-2 CT

failure which inturn resulted in tripping of elements

connected to 220kV Bus-1

1.APTRANSCO is recommended to submit Equipment

Failure Report regarding the failed CT to CEA.

2.APTRANSCO to sort out time synchronization

issues in 220kV Nunna SS.


Annexure-II

Page 14 of 48

85/III/1 Tripping of 400kV Ghani-

Narnoor line-1

21-05-2019 at

15:11 hrs


was not successful as fault was persistent in nature.

Fault was cleared in zone-2 time during A/r attempt

APTRANSCO is recommended to send a detailed

report regarding non-availability of Main CB (Main

CB was already in tripped condition in antecedent

condition) during the tripping and non-attempt of auto-

reclosure by Tie CB at Ghani end.


85/III/4 Tripping of 400kV

Talarichevu - Jamalamadugu

ckt-1

22-05-2019 at

19:21 hrs

R phase to Earth fault in the line. At Jammalamadugu

end A/r operated and line tripped due to persistent

fault. Main CB A/r not attempted at Talarichevu

APTRANSCO is recommended to submit a report

regarding non-attempt of A/R by Main CB at

Talarichevu end of 400kV Talarichevu -

Jamalamadugu ckt-1.


Annexure-II

Page 15 of 48

82/II/1 Tripping of 400kV KTPS VI-

KTPS VII

05-01-2019

at 10:17hrs

Line tripped at KTPS VI end due to suspected mal-

operation of over-voltage protection. Line was in

service from KTPS VII., BUS CVT secondary R

PHASE got grounded at KTPS VI

1) TSGENCO to configure OVR_start and

OVR_tripin EL at KTPS-VI end and sent a report after

completion of works related to DT communication

channel between KTPS-VI and KTPS-VII

TSGENCO TSGENCO mail dated 24.06.2019:

The issue is referred to M/s BHEL ( EPC vendor ) and the study on feasibility for

providing the communication with the existing available system is under process and

will be completed during the availability of next shutdown.


TSGENCO informed that the recommendations will be completed in September 2019

Pending

83/III/6 Tripping of 400kV Julurpadu

- Manuguru line-2

14-03-2019 at

06:10:00

Triggering incident was R-ph fault in the line. At

Julurpadu end, fault was sensed in Zone-2 and carrier

was received but due to DT Receive from manuguru

end, A/r not operated and line got tripped. FIR, DR and

EL of Manuguru end are not available.

It was noted that no representative of TSGENCO

attended the meeting. TSGENCO is recommended to

submit a report on the tripping and to furnish

equipment failure report to CEA.

TSGENCO TSGENCO mail dated 24.06.2019:

FIR, DR and EL was uploaded in SRLDC website.Trip Report was also submitted.


TSGENCO informed that Equipment failure report will be sent to CEA.

Pending

84/II/28 Frequent tripping of 220 kV

KTPS –Nunna line

05-04-2019 at

12:55 hr. B-N

FAULT

15-04-2019 at

13:20 hr. Y-N

FAULT

16-04-2019 at

14:04 hr. B-N

FAULT

22-04-2019 at

14:13 hr. R-N

FAULT

23-04-2019 at

13:31 hr. R-N

FAULT

04-05-2019 at

14:40 hr. B-N

FAULT

09-05-2019 at

14:31 hr. B-N

FAULT

05-05-2019 at

13:03 hr. B-N

In 155thOCC meeting of SRPC, APTRANSCO

informed that the tripping was due to clearance issues

in the ROW caused by mango tree. It was cleared and

issue was rectified. However, frequent tripping of line

is still persistent.

1. TSGENCO to check the non-operation of carrier

aided trip, when fault is detected at KTPS end in Z-2

and carrier is also received, and submit a report

regarding the same.

2. TSGENCO and APTRANSCO to ensure that

ROW is cleared periodically.

3.APTRANSCO & TSGENCO may consider raising

the height of towers if the line is planned to be used in

future.

4.TSGENCO to consider replacement of old

pneumatic CB’s at KTPS if 220kV KTPS- Nunna line

is planned to be used in future.

TSGENCO Yet to be informed Pending

Telangana

Annexure-II

Page 16 of 48


2 at Gajwel

11-04-2018 at

5:50 hrs

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

of Buchholtz relay.

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

mechanical protections under observation for detecting

any slippages.

2). TSTRANSCO was also asked to configure

capturing of mechanical protections of ICT’s in the

respective relay’s/ station’s event logger.

TSTRANSCO TSTRANSCO mail dated 20.06.2018:

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

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

2018. The mechanical protection of ICTs will be configured in the new relays ----

Pending


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

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


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

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

Pending

84/II/1 Tripping of 400kV Srisailam-

Dindi line-1 and 400kV

Mamidapalli-Dindi line-1

06-04-2019 at

17:39 hr.

400kV Mamidapally Dindi line-1 tripped on R-phase

to earth fault. 400kV Srisailam-Dindi line-1 tripped on

operation of cable differential protection at Srisailam

and direct trip was sent to Dindi.

1.TSTRANSCO to ensure time synchronization of DR

and EL at Mamidapalli end and Dindi end. Also in

coordination with TSGENCO sort out the time

synchronization issue in 400kV Srisailam – Dindi line-

1. 2.TSTRANSCO to ensure that A/R dead-time

is maintained as 1 sec uniformly at all Stations.

TSTRANSCO Yet to be informed Pending


2 and 3 at Dichipalli

Substation

22-04-2019 at

17:22 hr.

ICT#2 and 3 got tripped on suspected mal-operation of

LV earth fault relay during fault in 220 kV Dichpally-

Medaram feeder

1 .TSTRANSCO to ensure directional settings for ICT

earth fault protection and to ensure coordination

between line and ICT DEF protection.

2.TSTRANSCO to investigate the reason for non-

operation of LBB protection of 220 kVDichpally-

Medaram line while breaker lockout at Dichipalli SS

occurred.

3. TSTRANSCO to perform condition monitoring of

CB’s regularly to ensure sufficient air pressure for

proper CB operation.


84/II/27 Multiple tripping at 220 kV

Ghanapur station

27-05-2019 at

02:04 hr.

Triggering incident was failure of B-phase CT of bus

coupler of Bus-2. Bus bar protection of 220 kV Bus-2

operated resulting in tripping of all elements connected

to Bus-2.

1.TSTRANSCO is recommended to submit

Equipment failure report to CEA regarding the blast

CT.

2.TSTRANSCO to inform if any old CTs exist in

Ghanapur SS and ensure healthiness of the same to


84/III/4 Tripping of 400kV

Uravakonda - Veltoor ckt-1

13-04-2019 at

18:36 hr.

Y-phase to ground fault. Auto reclose didnot operate at

Veltoor end due to maloperation of STUB protection

1. TSTRANSCO to submit a report regarding the error

in PSL logic that led to the subject tripping along with

Remedial Measures taken.

2. TSTRANSCO to submit a report after checking mal-

operation of STUB protection on P444 relay.



3at Mamidapalli

21-05-2019 at

20:43 hrs

ICT tripped on PRV-1 indications due to ingress of

moisture into the relay

TSTRANSCO is recommended to ensure proper

sealing of PRV by providing suitable canopy to

prevent spurious operation of the same due to ingress

of moisture.


85/II/25 Tripping of 400kV KTPS-

VII - Julurupadu Line-2 &

tripping of 400/220kV ICT-

1&2 at Julurupadu substation

10-06-2019 at

8:22 hrs

Y-phase to earth fault occurred in 400kV KTPS-VII -

Julurupadu Line-2. Operation of over-voltage stg-2

resulted in tripping of line. 400/220kV ICT-1&2 at

Julurupadu on operation of over flux protection.

1.TSTRANSCO is recommended to check the v/f

settings of ICT-2 at Julurupadu since ICT-1 & 2

tripped at different time ( 3mins difference).

2.DGA analysis of ICT-2 shall be carried out to ensure

healthiness of ICT owing to very high voltage and the

tap position of ICT-2 also to be checked.


Annexure-II

Page 17 of 48

85/III/12 Tripping of 400KV-

Maheshwaram PG-

Mahbubnagar line-1

06-06-2019 at

19:18 hrs

Y phase to Earth fault in the line. A/r not operated at

Mahbubnagar

TSTRANSCO is recommended to submit a report

regarding non-attempt of A/R at Mehaboobnagar with

Remedial measures taken


Annexure-II

Page 18 of 48

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 Status received vide KPCL mail dated 14.12.2017:

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

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

the work is proposed to be taken up.


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

system has been prepared and proposal is placed for funds from PSDF. After the

approval of the DPR, the work is proposed to be taken up. Time frame requested for

is 2 yrs.


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

awaited. However, arrangements have been made to issue NIT.


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

completed in 2 years.


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


Arrangements have been made to issue NIT and Tender for the work proposed to be

floated during May- 2019.


NIT will be issued during May- 2019.


1. & 2. Completed

3) Preparation of technical specification is in progress. NIT will be issued during July-

2019.


KPCL informed that timeline for completion of work is December 2019.


1. & 2. Completed

3) Preparation of technical specification is in progress. NIT will be issued during July-

2019. timeline for completion of work is December 2019.

46/II/21 Trippings at 220kV Raichur

TPS

07-06-2015 at

01:35 hrs

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

on 220 kV side and keep it in healthy condition.

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

master trip relay.

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

under normal operation, and should go for single bus

operation only during emergencies.

KPCL Pending

Karnataka

Annexure-II

Page 19 of 48

Status received vide KPCL mail dated 10.07.2017:

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

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

Completed

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

is under observation. Till today in order and good condition. For remaining breakers,

since it is big order, approval for the same is under process. --- Pending

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

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

retrofitted in phased manner during R&M works.


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 --- PendingReview Meeting dated 19.12.2017:

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

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

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

2017. Main-I is Seimens make and Main-II is ABB make. --- Pending


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.KPCL mail dated 23.03.2019:

1) (i) & (iii)- Arrangements have been made to issue NIT and Tender for the work

proposed to be floated during May- 2019.

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

Numerical relays in 400KV station. & Being discussed with other utilities.

It is requested to furnish Necessary logic and settings to implement the breaker

flashover protection


1) (i) & (iii)- NIT floated on 01.03.2019



It is requested that SRPC may suggest/furnish reference of necessary logic and

settings to implement the breaker flashover protection.


1) (i) & (iii)- NIT floated on 01.03.2019. Cover-I opened. Technical evaluation is in

progress. Approval from Nodal Agency is awaited.



It is requested that SRPC may suggest/furnish referenc of necessary logic and Review meeting on 27.06.2019:

SRPC informed that referenc of necessary logic and settings to implement the breaker

flashover protection will be shared soon.


1) (i) & (iii)- NIT floated on 01.03.2019. Cover-I opened. Technical evaluation is in

progress. Approval from Nodal Agency for PSDF funds is awaited.

2) As confirmed during 84th PCSC meeting, SRPC may suggest/furnish referenc of

necessary logic and settings to implement the breaker flashover protection. reply in

this regard is awaited.

54/II/9 PendingKPCL 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

13-04-2016 at

21:12 hrs

Tripping of 400kV Raichur

TPS

Bus-2

Annexure-II

Page 20 of 48

Status received vide KPCL mail dated 10.07.2017 & 14.12.2017:

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

scheme for tripping of one bus during LBB/fault and maintaining the other bus intact

by tripping B/C breaker will be taken up in R&M works.


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

system has been prepared and proposal is placed for funds from PSDF. After the

approval of the DPR, the work is proposed to be taken up. Time frame requested is 2

yrs.

KPCL mail dated 20.12.2018 & 23.01.2019:

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

However, arrangements have been made to issue NIT.


NIT will be issued during May- 2019.


Preparation of technical specification is in progress.

NIT will be issued during June/July- 2019.

Review meeting on 27.06.2019:KPCL mail dated 16.07.2019:

NIT will be issued during July- 2019. Time line for completion of work is Dec-2020.

Tripping of Units at 220 kV

Raichur TPS

54/II/13 PendingKPCL 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.

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

Timeline?15-04-2016 at

15:36 hrs

Annexure-II

Page 21 of 48


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

per KPTCL MRT recommendation. - Completed

2. Work Under Progress ---- Pending

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

GPS system - Complied

4. Work Under Progress ---- Pending

Status received vide mail dated 14.12.2017:

1),3),4) Completed

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


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

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

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

synchronised with GPS ---- Completed


AMF panel procurement under progress.

KPCL mail dated 20.1.2.2018:

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

auxiliary panel with latest technology SCADA compatibility system'' . Availing Review Meeting on 21.12.2018:

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

would be completed in 1 year.


1) Completed.

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

completed in 1 year....Pending

3) Completed.

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

in 1 year....Pending

KPCL mail dated 23.03.2019:Review meeting on 27.06.2019:

.1 & 3) Completed.

4) Tender published on 21.06.2019 and time line in June 2020.

2. tender has to be issued. Timeline requested upto December 2020.


1 & 3) Completed.

2 ) NIT will be issued during Aug-2019.

4) Tender published on 21.06.2019. Time line for completion of Work is Dec-2020.


Numerical Generator protection relay replacement proposed to be taken up alongwith

SCADA work.


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


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

would be completed in 1 year.


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

completed in 1 year.


Tender for the work proposed to be floated during May- 2019 after model code of

conduct and work would be completed in 1 year


Tender will be floated during 3rd week of May- 2019.


Tender published on 21.06.2019.


69/II/8 PendingKPCLKPCL 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.

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.

PendingKPCL1) KPCL to check settings of LBB protection in all

relays from which it was implemented, and ensure that

their configuration, logic, and timing are in order at


2) KPCL to furnish details regarding the existing LT

auxiliary supply arrangement at their 220 kV Kadra

PH, and take steps to provide a suitable Auto-Main-

Fail (AMF) panel for DG set to effect its auto-starting

in case of failure of LT supply.

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

EL’s) with GPS at their 220 kV Kadra PH.

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

220 kV Nagjheri PH.

LBB of 220kV Kodasalli breaker at Kadra end got

operated which resulted in tripping of Bus at Kadra

and in turn led to tripping of all elements

06-09-2016

at 14:40 hrs


Kadra power station of

KPCL

58/I/3

(GD)

06-10-2017 at

22:22 hrs

Tripping of 220 kV Kaiga-

Kadra line-1

Annexure-II

Page 22 of 48


Tender published on 21.06.2019. Time line for completion of Work is Dec-2020.


Sedam, Shahapur, Shahabad,

Kapanoor, Humnabad and

Halabarga Stations of

KPTCL

01-02-2018

at 17:46 hrs

High resistance fault occurred in 110kV Sedam-

Chittapur line near Sedam end. Line DEF operated and

backup OC protection of 100MVA transformer

operated at Sedam end. But line breaker and

transformer HV breaker didn’t open due to problem in

trip circuit. This resulted in cascade tripping of

upstream feeders and power supply was lost to six

220kV stations of KPTCL.

KPCL to disable GFC protection on all lines

emanating from their generating stations.

KPCL Review Meeting on 21.12.2018

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

furnished soon.


'GFC protection will be disabled in all lines in coordination with M/s.KPTCL

KPCL mail dated 10.05.2019 & 25.06.2019:

Letter addressed to CE, RT, KPTCL dated: 10.04.2019 to disable GFC protection

in all 220kV lines . Reply is awaited.


Letter addressed to CE, RT, KPTCL dated: 10.04.2019 to disable GFC protection

in all 220kV lines . Reply is awaited.

Pending


Varahi power station

15-03-2018 at

22:36 hrs

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

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

phase, the breaker failure protection operated resulting

in operation of 220KV bus bar protection at Varahi,

tripping all the connected lines and Varahi running

units.

KPCL to take steps to put double-bus operation into

service at their 220 kV Varahi PH.

KPCL Status received vide mail dated 25.07.2018:

Under Implementation.

KPCL mail dated 20.12.2018 & 23.01.2019 & 23.03.2019:

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

April-2019


4 Set of Isolators of VS1, VS2 & VM2 bay of North Bus were cmpleted. Remaining

bays will be completed after Concurrence of LC from LDC

KPCL mail dated 25.06.2019 & 16.07.2019:


bay will be completed after monsoon season i.e during November -2019

Pending

78/I/1 Complete Outage of 220 kV

Varahi UGPH.

24-08-2018 at

11:00 hrs

Due to suspected mal-operation of 220KV bus bar

protection at Varahi, all the connected lines and Varahi

running Units got tripped. (6 nos 220kV lines and 4

nos Varahi generating station running Units). This

resulted in complete outage of 220kV Varahi UGPH

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

service at their 220 kV Varahi UGPH by December,

2018.

2. KPCL to employ correct operational practices like

keeping DC fuses of B/C CB intact during bus

changeover works, disabling back-up protections of

B/C CB during bus changeover works & enabling

them with proper settings only when it is used as Main-

CB of the grid elements.

KPCL KPCL mail dated 20.12.2018 & 23.01.2019:

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

after April-2019 --- Pending

2. ---- Completed.


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

after April-2019



bays will be completed after Concurrence of LC from LDC.

KPCL mail dated 25.06.2019 & 16.07.2019:


bay will be completed after monsoon season i.e during November -2019

Pending

69/II/8 PendingKPCLKPCL to take steps to replace the existing static

protection relays for Generator Units and Generating

Transformers (GT’s) with suitable Numerical relays at


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.

06-10-2017 at

22:22 hrs

Tripping of 220 kV Kaiga-

Kadra line-1

Annexure-II

Page 23 of 48


1) Preparation of technical specification is completed. Tender will be floated during

3rd week of May- 2019 for control & protection system along with SCADA.

2) English Electric make static type relay is used for NPS protection system at Unit

no.2. The detailed report shall be furnished shortly.


1) Preparation of technical specification is completed. Tender will be floated during

1st week of July 2019 for control & protection system along with SCADA.

2) Existing relays are English Electric Static type

@ GT -2 side, Unit breaker opened at 3MW, HV side current is

0.045A(CTR:200/1A), Since LBB setting I= 0.2A, t=0.2sec, Hence LBB is not

operated.

at the same time,@Generator-2 side ,current is 0.9A(CTR-4000/5A, I2s=7.5% of

secondary current i.e alarm=80% of I2s(i.e 0.3A pickup value), since R pole of

breaker closed condition till manual opening of all 4lines, Due to continous

current(>0.3A), However, NPS operated.


1. Timeline for completion of work July 2020.

2. PCSC confirmed the correctness of NPS relay settings adopted at Kadra. --

Completed.


1) Tender published on 21.06.2019. Time line for completion of Work is Dec-2020.

2) Completed.


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

up by KPTCL. Problem in the 220kV bus coupler breaker is attended and isolator

overhauling work is under progress. Spilt bus operation at Ambewadi will be made

possible at the earliest. --- Pending

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

instance is checked up and remedial measures already furnished in this regard.

---- Completed

Mail recieved on 29-07-2015: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.

KPTCL mail dated 20.12.2018:Mail received on 28-04-2015:

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

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

will be enabled.


1. Procurement of Bus bar and LBB protection is in the final tendering stage. KPTCL Mail dated 16.12.2017:

1 & 2) Replacement of Bus Bar Protection is included under R&U project. Awarded

to M/s GE Ltd. Panels have alredy been supplied by the Agency. The work will be

taken up on top priority.


PendingKPTCLTriggering incident was B-phase to earth fault in

220kV Ambewadi- Nagzari line-1. B-pole of breaker

did not open at Ambewadi end. LBB protection not

available at Ambewadi end. All elements tripped on

Zone-2 from remote ends.

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

LBB protection, KPTCL shall explore the possibility

of having split bus operation at Ambewadi and submit

the details of the same to PCSC forum.

2. KPTCL shall provide the details of the tripping of

Supa hydro station connected downstream from 110

kV bus.

1. Status? 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.

27-01-2015 at

8.00 hrs

40/I/1 22-12-2014

at 21:22 hrs

Complete outage at 220kV

Sedam Substation of KPTCL

(GD-1)

KPTCL

PendingKPCL

GD-1 at 220kV Ambewadi

Station of KPTCL

1) KPCL to ensure that DR and EL for all events are

made available. If Static relays with no DR are present

in Station, standalone Disturbance recorder and Event

logger should be provided.

2) KPCL to investigate the operation of Negative

sequence relay and report to SRPC since the operation

of Negative sequence relay due to stuck breaker

condition is not proper as per protection philisophy

During de-synchronising of Kadra unit#2, R-pole

didn’t open due to struck breaker condition. Pole

Discrepancy operated. All the connected 220kV lines

at Kadra end were hand tripped.

04-02-2019 at

20:19 hrs

Complete Outage of 220kV

Kadra Power House of

KPCL & 220kV Karwar SS

of KPTCL

82/I/3

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.

41/I/4 Pending

Annexure-II

Page 24 of 48


1. Bus Bar protection will be provded under R&U.

2. A/R yet to 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 Recieved dated 22-11-2017:

Bus Bar Protection panel and required Wave traps are supplied under R&U. Wave

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

restored AR will be enabled.


1. Replacement of Bus Bar Protection is included under R&U project. Awarded to

M/s GE Ltd. Panels have alredy been supplied by the Agency. The work will be taken

up on top priority.

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


1 & 2) KPTCL informed that the works are under progress and are targeted to be

completed by February, 2018. Review meeting on 27.06.2019:

1. Timeline - September 2019

2. Completed


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

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

line. AR will be enabled after restoration of PLCC.

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

1.Enabling the AR feature was discussed during PCSC meetings and since Ambewadi-

Ponda and Ambewadi-Xeldom lines are radial lines, it was decided that enabling AR


The protection issues pertaining to Ambewadi was appraised to the management

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

management. Further as per SRPC directions and in view of attending protection audit

recommendations pertaining to Ambewadi SS without linking with new Station

proposal, action has been taken to include the works in extended scope of R&U

project awarded to M/s GE T&D India Limited. Addition materials required are yet to

be supplied by M/s GE. work expecnted to be completed in 5 months.


1. Since 220kV Ambewadi -Ponda line is radial, this recommendation is dropped.

2. Timeline will be in timated by KPTCL

15-02-2015

at 14:24 hrs

42/I/2

(GD)

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.

Fault occurred in 220kV Sedam-Shahpur line42/I/1 Pending

Fault in 220kV Ambewadi-Nagjheri line-2Complete outage of 220 kV

Ambewadi substation of

KPTCL

PendingKPTCL1. 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

12-03-2015 at

7:51 hrs

Complete outage of 220kV

Sedam substation of KPTCL

Annexure-II

Page 25 of 48

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-


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-


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.


The protection issues pertaining to Ambewadi was appraised to the management

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

management. Further as per SRPC directions and in view of attending protection audit

recommendations pertaining to Ambewadi SS without linking with new Station

proposal, action has been taken to include the works in extended scope of R&U

project awarded to M/s GE T&D India Limited. Addition materials required are yet to

be supplied by M/s GE. work will be completed in 5 months


1. Work order plced. Timeline requested December 2019.

Status?48/I/3 PendingKPTCL KPTCL to fast-track providing A/R on all 220 kV

lines emanating from Ambewadi SS to prevent Station

shut-down on temporary faults.

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.

30-09-2015 at

10:41 hrs

Outage of 220kV Ambewadi

station in Karnataka

Annexure-II

Page 26 of 48

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.


Bus sectionaliser breakers have to be provided for operating Shimoga in multi bus

mode. Estimates have to be prepared by CEE,TZ,Hassan. Work expected to be

completed in 1 year.


1. The necessary Bus Bar protection panels are already supplied to Chikkodi under

R&U project. Presently R&U works at sub stations subjected to audit are taken up.

After completion of PAR works, the baove works are planned.

--- Pending

2. --- Pending

3. --- Pending


1.The necessary Bus Bar protection panels are already supplied to Chikkodi under

R&U project. Control cables have to be supplied. Presently R&U works at sub

stations subjected to audit are taken up. After completion of PAR works at 26 Sub

stations, remaining works will be taken up through M/s GE.

--- Pending.

2. --- Pending

3. --- Pending


1. KPTCL informed that BBP would be provided by April, 2018.

---- PendingKPTCL mail dated 20.12.2018:

1). Bus Bar Protection work is included under R&U. work expected to be completed

in 3 months ---- Pending

2). Major equipment failure reports are being sent to CEA regularly ----

Completed.


1. Timeline for completion of work is September 2019

2. Completed

220kV Bus Bar protection operated during failure of R

phase CT in DVG-2 line bay.

22-02-2016 at

15:03 hrs

57/II/1 PendingTriggering 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.

KPTCL1.KPTCL to take steps to provide busbar protection at

their 220 kV Chikkodi inter-regional substation, and

furnish a time-line for the same.

2.KPTCL to review distance protection settings for

220 kV Chikkodi – Kudachi line.

3.KPTCL to furnish equipment failure report of the

current incident to PSE&TD Division of CEA with a

copy marked to SRPC.

KPTCLKPTCL to operate 220 kV Shimoga on multi-bus

operation under normal conditions, and put it on single-

bus operation only under emergency conditions.


Shimoga substation

Tripping of 220 kV Chikkodi-

Mudshingi and 220 kV

Chikkodi-Talandage lines

01-07-2016 at

03:03 hrs

Pending52/I/3

Annexure-II

Page 27 of 48

KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works.


1). The R&M work of 220kV Hoody SS is under progress and expected to be

comleted before the end of August 2019. Providing Bus Bar Protection to 220kV

buses is a part of R&M work at Hoody ----- Pending

62/II/5 Tripping of 220 kV South

Bus and connected elements

(220kV HSR, 220kV

Nagnathpura, 220 kV

Harohalli, 220 kV

Subramanyapura, 220 kV

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

Pending

74/I/2 Complete outage of 220 kV

Ambewadi station

02-04-2018 at

13:46hrs

Loss of supply occurred to 220 kV Ambewadi station

due to tripping of 220kV Nagzhari-Ambewadi line-2

(Source) from Nagzhari power station. After bus dead,

Ambewadi-Ponda lines – 1 & 2 were hand-tripped. In

antecedent conditions, 220kV Ambewadi - Nagjheri

ckt-1, 220kV Ambewadi-Narendra Ckt-1 &2 were out

of service.

1). KPTCL to review operation of SPS at NPH for

proper functionality and changed network conditions

(reduction of generation with tripping of evacuating

lines) and put it into service at the earliest.

2). KPTCL to furnish equipment failure report of the

current incident (R-phase CT in Nagjheri – 1 bay at

KPTCL KPTCL mail dated 20.12.2018:

1). To be reviewed. Expected to be completed in 1 month.---- Pending

2), Being followed ----- Pending


1. Nagjheri SPS shall be studied in view of changed system configuration

Pending

74/II15 Multiple Trippings at

400/220kV Guttur station

21-04-2018 at

12:50 hrs

Triggering incident was fault in 220 kV Davanagare -

Shimoga line. Bus bar protection operated at Guttur

resulting in tripping of all the connected elements. 220

kV Guttur was on single bus operation due to CVT

problem in Bus-2.

KPTCL to put double-bus operation at their 220 kV

Guttur substations by attending to Bus-2 CVT

problem.

KPTCL KPTCL mail dated 20.12.2018:

Bus-2 CVT problem is attended. However due to breaker replacement works, 220kV

side operated in single bus mode.


KPTCL informed that double-bus operation at their 220 kV Guttur would be provided

within two months.

Pending

79/III/9 Tripping of 400 kV JSWEL

–Guttur line

29-09-2018

at 11:30 hrs


was not attempted at JSWEL due to DT receive. At

Guttur end auto-reclose could not be validated with

DR/EL.

KPTCL to furnish a detailed report on tripping event

bringing out reasons for DT sending from Guttur end

to JSWEL on 400 kV Guttur - JSWEL line along with


KPTCL Review Meeting on 21.12.2018:

KPTCL was aksed to furnish status of implementation of the recommendation given

at the earliest.


Pending

80/II/7 Tripping of 400 kV JSWEL-

Guttur line

17-10-2018 at

02:04 Hrs

Triggering incident was R-phase to earth fault in line.

At Guttur end there was operation of pole discrepancy

and resulted on tripping of Y & B pole after a duration

of 2 seconds from the occurrence of fault. FIR, DR &

EL of Guttur end were not furnished.

KPTCL to examine the reasons for sending of DT from

Guttur end to JSWEL end, and furnish an action taken

report including remedial measures taken to rectify the

same.

KPTCL Review meeting on 27.06.2019:

report will be submitted by KPTCL

Pending

82/I/4 Complete Outage of 220kV

Ambewadi Station of

KPTCL

06-02-2019 at

14:51hrs

Fault occurred while test charging of 220kV

Ambewadi – Nagjheri Line -2 from Ambewadi end.

Suspected stuck breaker condition at Ambewadi end)

led to clearing of fault by tripping of remote end

breaker in Zone-2. LBB protection is not active at

220kV Ambewadi station.

KPTCL to investigate the reason for non-tripping of

220kV Ambewadi - Nagjheri line-2 on operation of

SOTF and submit a report regarding the same to

SRPC. Also KPTCL to take necessary measures in

order to ensure healthiness of breaker before

testcharging of any line.



Pending

Tripping of 220 kV Bus 2

and connected elements

(220kV HAL #1 and 2,

400/220 kV ICT- 1, 2 and

220/66 kV ICT-2) at

400/220 kV Hoody

substation of KPTCL (Load

loss : 590 MW)

62/II/3 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.

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

KPTCL Pending09-01-2017

at 23:06 hrs

Annexure-II

Page 28 of 48


Alipura substation

20-02-2019 at

12:45 hrs

As informed by KPTCL, Suspected delayed clearance

of fault in 220 kV BTPS-Lingapur line from BTPS end

resulted in tripping of lines from Alipura S/s.

1) KPTCL is recommended to furnish detailed report

regarding spurious operation of DEF at Alipur SSand

check the directionality of DEF on all lines.

2) KPTCL is requested to share the revised zone

settings for Distance protection at BTPS end.



Pending

82/II/12 Tripping of 400kV Kaiga-

Guttur line-1&2

07-02-2019

at 11:49 hrs

Line-1 tripped due to insulator flashover. Line-2

tripped due to zone-3 operation at Kaiga and Direct

trip receive at Guttur

KPTCL is recommended to take necessary measures to

ensure that Main-I and Main-II at Guttur end shall be

of different types (make and model) coherent with the

general protection philosophy followed in SR region.


KPTCL informed that the recommendation has been included as part of R & M work.

Timeline will be informed

Pending

84/II/12 Tripping of 400kV DHONI

GUTTUR line- 1

18-04-2019 at

18:59 hr.

Triggering incident was failure of B-ph CB of 400kV

Dhoni-Guttur line at Dhoni end. This resulted in the

operation of LBB of bus-1 and DT was sent to Guttur

end

1. KPTCL to send equipment failure report,

corresponding to the failed CB at Dhoni SS, to CEA.

2. KPTCL to ensure time synchronization at Guttur

end.

KPTCL Yet to be informed Pending


Nelamangala-Mysore line-2

01-05-2019 at 02:29 hr.Line tripped on operation of over voltage stg-2 at

Nelamangala end

KPTCL to ensure time synchronization of DR and

EL with GPS signal at Nelamangala end.



1&3 at Hoody Substation

13-05-2019 at

15:35 hr.

ICT-3 tripped on operation of 59N neutral

displacement relay. ICT-1 tripped on OCR.

KPTCL to inform PCSC forum regarding the changes

implemented in Hoody ICT SPS and to ensure time

synchronization of relays at Hoody SS.


85/I/4 Tripping of 220kV Sedam-RTPS

line-1&2 and 220kV Sedam-

Tandur line

14-06-2019

at 02:00 hrs

Tripped on Directional Earth Fault indications in Main-

2 relay at Tandur end for fault at Raichur end. Sedam

end details not furnished.

1. KPTCL is recommended to enable A/R on all lines

emanating from 220kV Sedam SS.

2.KPTCL is recommended to commission BBP at

220kV Sedam SS immediately.


85/II/5 Tripping of 400/220 kV ICT-3 at

Nelamangala substation19-05-2019

at 16:11 hrs

As per FIR, ICT-3 got tripped on operation of High Set

Over current trip on 400kV side

1. KPTCL is recommended to enable auto-reclosure

on all lines emanating from 400/ 220kv Neelamangala

SS and to ensure time synchronization of relays at

Neelamangala SS.


85/II/11 Tripping of 400kV Hoody-

Yelahanka line-125-05-2019

at 20:41 hrs

Line tripped at Hoody end only and was holding from

Yelahanka.

KPTCL is recommended to check the spurious

operation of SOTF protection at Hoody SS and submit

a report to SRPC regarding the same .


Annexure-II

Page 29 of 48

85/II/12 Tripping of 400/220 kV ICT-1at

Guttur Substation26-05-2019

at 10:00 hrs

LV side of 400kV/220kV 315MVA ICT#1 Guttur got

tripped due to CB lockout (B phase)because of low

SF6 gas in the CB

1. KPTCL is recommended to submit a report to SRPC

after the CB pressure leakage problem is attended by

OEM.

2.. KPTCL to ensure that during recharging of Circuit

breakers, cylinders with Non-return valve only are

used to prevent sudden pressure drop in Circuit

breakers.


85/II/22 Tripping of 400kV Dhoni-

Munirabad line06-06-2019

at 02:01 hrs

Line got tripped at Dhoni end. From DR Zone-3 start,

PSB and A/r block was observed.

KPTCL is recommended to submit a report regarding

PSB maloperation along-with the RM suggested by

OEM. Proper legends shall be ensured for digital

signals at Doni end.


85/II/27 Tripping of 400/220kV ICT-2 at

Hoody substation16-06-2019

at 19:20 hrs

ICT-2 got tripped on operation of over-flux protection KPTCL is recommended to adopt v/f settings as per

manufacture suggested curve.

v/f setting for alarm: 1.1 time Vnominal; Time delay

10 seconds;

v/f trip setting : v/f is 1.2 time Vnominal;Time delay

60 seconds


85/II/29 Tripping of 400kV Hiriyur-

Nelamangala line-1 and 400kV

Gooty-Nelamangala line

22-06-2019 at

04:06hrs

400kV Hiryur-Nelamangala line-1 : 'Y' phase bushing

of Hiriyur line-1 reactor failed at Nelamangala end

resuting in a R-Y phase fault. Direct trip was sent to

Hiryur.

400kV Gooty-Nelamangalaline : Line tripped at

Nelamangala end only due to mal-operation of Main-2

distance protection relay (THR).

KPTCL is recommended to submit equipment failure

report to CEA regarding the reactor bushing failure

and also to sort out time synchronization issues of

400kV Hiriyur-Nelamangala line.


85/II/30 Tripping of 400/220kV ICT-1&2

at Munirabad substation24-06-2019

at 20:50 hrs

400/220kV ICT-1&2 at Munirabad end got tripped due

to operation of High set of backup earth fault relay

during failure of Y phase CT in 220kV Munirabad-

Kalyani steel feeder at Kalyani steel end

KPTCL is recommended to submit equipment failure

report to CEA regarding the CT and PT failure.


Annexure-II

Page 30 of 48


1. coordination of KPCL has been requested for enabling AR lines terminated to

Nagajari.

2. AR will be enabled at Ambewadi end for lines other than Ponda and Xeldom lines

during retrofitting of Back Up protection by Distance protection relay at Ambewadi.

KPTCL Mail dadted 16.12.2017 & Review Meeting dated 19.12.2017:

1. KPTCL informed that Coordination of KPCL has been requested for enabling AR

lines terminated to Nagajari.

--- Pending

2. KPTCL informed that AR would be enabled at Ambewadi end for lines other than

Ponda and Xeldom lines during retrofitting of Back Up protection by Distance

protection relay at Ambewadi. -- Pending


2). Readiness from KPTCL for implementing AR is already confirmed to KPCL. KPCL mail dated 23.03.2019:


version Numerical Line protection relays having IEC61850. Prepration of

specification is under progress.


1) Budgetary offer obtained for replacement of existing PZ1000 relays with new

version Numerical Line protection relays having IEC61850. Preparation of estimation

and specification is under progress.

KPCL mail dated 25.05.2019 & 16.07.2019:



NLDC for DPR is awaited. Further, availing administrative approval for issue of NIT

for replacement of existing PZ1000 relays with new version Numerical Line

protection relays having IEC61850 and preparation of estimation and specification is

under progress. Timeline for completion of work is July 2020.

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

Pending

PendingKPCL/ KPTCL 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.

220kV lines from Nagjheri power house started

tripping from 11:00 hrs due to fault in lines. The

sequence of tripping is shown in SOE list. At 12:33

hrs, 220kV Narendra-Ambewadi lines-1&2 got tripped

which resulted in loss of evacuation path to Nagjheri

station resulting in tripping of running Units and

complete outage at Nagjhheri power station. 220kV

Ambewadi station also got de-energized due to tripping

of source feeders i.e. 220kV Narendra-Ambewadi-1&2

and 220kV Nagjheri-Ambewadi-1&2.

22-02-2016 at

12:36 hrs


Nagjheri power station and

220 kV Ambewadi

substation of KPTCL

51/I/3

49/I/3 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/ KPTCL220kV 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


Ambewadi Substation of

KPTCL

29.10.2015 at

14:34 hrs

Annexure-II

Page 31 of 48


1) & 3). --- Completed.


yet to be discussed and approved by the SRPC forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested

certain changes for suitable incorporation. KPTCL agreed to look into the same and

assured that the modified SPS would be furnished by January, 2018.


2. KPTCL informed that Nagjheri SPS shall be finalised in 1 month.

KPCL mail dated 23.01.2019 & 23.03.2019:

1) .....Completed


3) .....Completed

KPCL mail dated 13.05.2019 & 25.06.2019

1. 3. Completed




2. KPTCL informed that Naghjeri SPS need to be revisited in view of changes in KPCL mail dated 16.07.2019:

1 & 3) Completed.



PendingKPCL/ KPTCL 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.





220kV lines from Nagjheri power house started

tripping from 11:00 hrs due to fault in lines. The

sequence of tripping is shown in SOE list. At 12:33

hrs, 220kV Narendra-Ambewadi lines-1&2 got tripped

which resulted in loss of evacuation path to Nagjheri

station resulting in tripping of running Units and

complete outage at Nagjhheri power station. 220kV

Ambewadi station also got de-energized due to tripping

of source feeders i.e. 220kV Narendra-Ambewadi-1&2

and 220kV Nagjheri-Ambewadi-1&2.

22-02-2016 at

12:36 hrs


Nagjheri power station and

220 kV Ambewadi

substation of KPTCL

51/I/3

Annexure-II

Page 32 of 48

KPCL mail dated 23.01.2019 & 23.03.2019:

1) …Completed.


3) …Completed.

KPCL mail dated 10.05.2019 & 25.06.2019:

1. & 3. Completed




2. KPTCL informed that Naghjeri SPS need to be revisited in view of changes in

system configuration.


1 & 3) Completed.




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.


yet to be discussed and approved by the SRPC forum --- Pending


2. The SPS proposed by KPTCL was discussed and the PCSC forum suggested

certain changes for suitable incorporation. KPTCL agreed to look into the same and

assured that the modified SPS would be furnished by January, 2018.


KPTCL informed that Nagjheri SPS shall be finalised in 1 month.

53/I/3 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.





PendingKPCL/ KPTCLAmbewadi 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

Tamil Nadu


Ambewadi station of

KPTCL and 220kV Nagjheri

of KPCL

18-03-2016 at

14:40 hrs

Annexure-II

Page 33 of 48

Mail dated 18.07.2019

2) Tender has been lodged two times. New indent was reaised on 06.07.19. and

tender floating is expected by August 2019. 3) Tender has been

lodged on 15.07.19 and new indent would be raised for the same shortly.

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.

PendingTANGEDCO1. 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.

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.

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

Busbar protection got operated for a fault in 230kV

Mywadi-Anaikadavu line

TANTRANSCO to examine the feasibility of

providing two main-zone operation for bus bar

protection by exploring various alternatives like

replacing existing bus-coupler CB with a hybrid bus-

coupler CB that comes with inbuilt CT, replacing

existing BBP relay with another suitable relay that

supports two main-zone operation, and implement the

same.

TANGEDCO 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


1) Check zone New Relay is replaced on 17.04.2017 -- Completed.

2. --- Pending

3. --- Pending


2).P & C wing gives clearance to TTPS to procure the Bus bar protection relays and

protection relays and SER / DR system vide

Lr.CE/P&C/SE/D/EEPC4/AEE3/F.TECH/D.27/17 Dated: 05.10.2017. To get

administrative approval budgetary offer has bar protection relay from various

companies ----Pending

3). SRPC vide Lr: SRPC/SE- III/CEA/2017/6450/DT:27.10.2017 gives features of

SER/DR. Budgetary offer will be called for SER / DR having above features. ---

Penidng


2) & 3) The issue was discussed and TANGEDCO was asked to provide time-line for

implementing the recommendations.

Mail dated 29.01.2018:

Procurement work is under progress and will be completed by December 2018.


TANTRANSCO informed that Tender would be floated by January 2019 and

Procurement is expected by APril 2019. Works would be completed by December

2019.


2. Tender issued. Timline- July 2020.

3. Tender has to be issued. Timline- July 2020.

21-12-2015 at

6:28 hrs


Mywadi station of

TANTRANSCO

PendingTANTRANSCO

Status?

Annexure-II

Page 34 of 48

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.


Civil work completed & CT will be commissioned after strengthening Bus .2

conductor jumpers.Awaiting Bus LC Time line before January 2019.


Erection under progress will be completed before 31.01.2019


Buscoupler bay will be commissioned by June 2019


Buscoupler bay configuation in BBP will be completed by June 2019. Bus

segregation will be ensured by 31.12.2019 after attending Isolator status feedback.


Buscoupler bay configuation in BBP will be completed by June 2019. Bus

segregation will be ensured by 31.12.2019 after attending Isolator status feedback.

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.


Numerical Busbar protection relay commissioned on 14.05.2018


Control & Status of isolator feedeback to be provided by replacement of Drive

Mechanism box.



Mechanism box.



Mechanism box. Timeline requested upto Dec 2018.


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

feedback. Work under progress. Lightning mask work under progress will be

completed within three days.


TANTRANSCO informed that Double bus operation would be provided by March,

Pending55/I/1

(GD)


Gummidipoondi Station of

TANTRANSCO

12-05-2016 at

12:15 hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV

Southern Bus occurred at Gummidipoondi station. At

the time of fault, Bus bar protection relay was not in

service for pre-commissioning testing of Auto

Transformer-2. All feeders got tripped due to operation

of zone-2 protection from remote ends.

Busbar protection got operated for a fault in 230kV

Mywadi-Anaikadavu line

TANTRANSCO to examine the feasibility of

providing two main-zone operation for bus bar

protection by exploring various alternatives like

replacing existing bus-coupler CB with a hybrid bus-

coupler CB that comes with inbuilt CT, replacing

existing BBP relay with another suitable relay that

supports two main-zone operation, and implement the

same.

TANTRANSCO TANTRANSCO to take steps to provide double-bus

operation at their 230 kV Gummidipoondi SS.

21-12-2015 at

6:28 hrs


Mywadi station of

TANTRANSCO

PendingTANTRANSCO

Annexure-II

Page 35 of 48



time line requested upto June.2019.



time line requested uptoSep.2019

Pending55/I/1

(GD)


Gummidipoondi Station of

TANTRANSCO

12-05-2016 at

12:15 hrs

Flashover of Auto Transformer- 2 HV

B-phase Isolator supporting insulator of 230kV

Southern Bus occurred at Gummidipoondi station. At

the time of fault, Bus bar protection relay was not in

service for pre-commissioning testing of Auto

Transformer-2. All feeders got tripped due to operation

of zone-2 protection from remote ends.

TANTRANSCO TANTRANSCO to take steps to provide double-bus

operation at their 230 kV Gummidipoondi SS.

Annexure-II

Page 36 of 48

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.


provision of Different make Relays for Main-I & Main-II will be completed by

September, 2018.



end in a phased manner. Timeline: September-2018.




TANTRANSCO MAIL DATED 11-12-2018:

Different make Relays will be provided for Main-I & II relays at Sunguvarchatram TANTRANSCO MAIL DATED 23.01.2019:





end in a phased manner. Timeline: September-2019

14-09-2016 at

11:13Hrs

Bus Bar Protection (Zone-2) of 230 kV Bus-B got

operated at Alamathy Station during fault in 230 kV

Alamathy-Korattur feeder.

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.


Alamathy Station

TANTRANSCO Pending

Mail received on 10-11-2016 & 20.12.2016:

1. The Bus Bar Protection scheme will be tested for healthiness including the CT

circuits.

2. High impedance BBP relay will be replaced by Numerical relay.

Status received vide mails dated 10.01.2017 & 12.04.2017 & 01.06.2017 & 15-06-

2017:

1. The Bus Bar Protection scheme was tested for healthiness including the CT

circuits. AREVA make CTs in Alamathy SS are having different kneepoint voltage

for the cores. CT cores of higher knee point voltage has been choosen for BBP in

230kV Korattur, 230kV OPG-1 & 230kV OPG-2 feeders on 29.11.2016. ----

Completed.

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending,

Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-2017 & 12-

12-2017.

1. ---- Completed

2. High impedance BBP relay will be replaced by Numerical relay. --- Pending


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

--- Pending

TANTRANSCO mail received on 25-01-2018:

1. --- Complied.

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

2018.

TANTRANSCO MAIL DATED 22.05.2018 & 08.06.2018 & 23.07.2018:

2.Numerical BBP relay will be provided. Timeline: Sep-2018.


1. Complied


PendingTANTRANSCO

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]

58

Annexure-II

Page 37 of 48

TANTRANSCO MAIL DATED 11-12-2018:

Numerical BBP relay to procured. Timeline: Sep-2019.


Numerical BBP relay to be procured. Timeline: Sep-2019.


Numerical BBP relay to be procured. Timeline: Sep-2019.


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.


Alamathy Station

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.




1. Complied


Pending

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.

TANTRANSCO

Annexure-II

Page 38 of 48

64/1/4 Complete outage of North

Chennai TPS STG-1

26-03-2017

at 23:14hrs

Tripping of evacuating lines due to fault led to tripping

of running Unit at NCTPS Stg-1

1. TANTRANSCO to take steps to complete insulator

replacement works on the 230 kV lines owned by them

in NCTPS area within 6 months.

2. TANTRANSCO to take steps to implement A/R on

all 230 kV lines emanating from NCTPS-I at the

earliest.

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

1. All the Porcelain insulators were replaced with Polymer insulators in 230kV

NCTPS-I - Tondiarpet feeders - 1 & 2.

---- Completed

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


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.



from NCTPS-I within six months. Timeline:June-2018.

Pending




from NCTPS-I Timeline:Sep -2018.


1. Complied.

2. The scheme needs modification to enable AR, since AR was not envisaged for this TANTRANSCO MAIL DATED 11-12-2018:

2. Enabling AR pending for 3 feeders. ( Sriperumpudhur end breaker problem,

Tondiarpet & Alamathy feeder . static relay to be replaced. Timeline - 1 year


Enabling AR pending for 3 feeders. ( Sriperumpudhur end breaker problem,

Tondiarpet & Alamathy feeder . static relay to be replaced. Timeline -Sep 2019


Enabling AR pending for 3 feeders. ( Sriperumpudhur end breaker problem,

Tondiarpet & Alamathy feeder . static relay to be replaced. Timeline -Sep 2019

77/II/9 Multiple trippings at

400 kV Manali Substation

TANTRANSCO to refer the issue of selective tripping

of 400 kV side breakers, and non-tripping of 230 kV

side breakers due to operation of Densimeters on low

pressure in the instant case to their OEM, and share

OEM’s advice/ remedy in this regard.


OEM will be referred


TANTRANSCO was asked to update the status.

TANTRANSCO MAIL DATED 23.01.2019, 19.03.2019 & 13.06.2019:

The issue was referred with OEM & reply awaited.


OEM reply shall be communicated by end of July 2019


The issue was referred with OEM & reply awaited

Pending

Annexure-II

Page 39 of 48


Thiruvalam Substation

05-10-2018 at

14:32 hrs

Bus-1 got tripped at 230 kV Thiruvalam substation due

to spurious LBB relay (independent) operation of

230kV Thiruvalam Chittoor line. 230kV Thiruvalam

substation was under single bus operation; hence

operation of LBB protection resulted in tripping of all

connected elements resulting in the complete outage

TANTRANSCO to take steps to implement multi-bus,

multi-zone operation (Double-bus operation) at their

230 kV Thiruvalam SS by December, 2018.

TANTRANSCO TANTRANSCO MAIL DATED 11-12-2018:

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


It was noted that the station was on a single (Main) bus and there was not even

transfer bus. In view of the importance of 230 kV Thiruvalam SS, TANTRANSCO

was asked to take steps to provide dobule-bus operation at their 230 kV Tiruvalam

SS.


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

will be taken. Time upto Sep 2019


Bus segregation will be ensured by providing bus coupler bay by extending the


Pending

80/II/12 Tripping of all elements

connected to 230 kV

Anaikadavu SS

06-11-2018 at

21:35 Hrs

Triggering incident was failure of R-ph PT of 230 kV

Anaikadavu Bus-1. 230 kV Bus bar protection of bus-

1 operated resulting in tripping of all the connected

elements. 230 kV Anaikadavu was on single bus

operation due to failure of Bus-2 PT during antecedent

conditions.

1) TANTRANSCO to adopt recommended OVR,

Stage-I and OVR, Stage-II protections at their 400 kV

Anaikadavu and 400 kV Rasipalayam stations, and to

ensure that OVR-I_START signal is configured for

triggering corresponding Event Logger (EL), and OVR-

I_TRIP is configured for triggering corresponding

Event Logger (EL) and Disturbance Recorder (DR).

2) TANTRANSCO to take steps to restore multi-bus,

multi-zone operation at their 230 kV Anaikadavu SS at

the earliest.

TANTRANSCO TANTRANSCO MAIL DATED 23.01.2019 & 19.03.2019:

1……Complied

2.Bus PT is to be supplied by the Turnkey contractor will be replaced by 31.03.2019


Bus PT is to be supplied by the Turnkey contractor


Timeline requested upto December 2019.


Bus PT is to be supplied by the Turnkey contracto

Pending


Sriperumbudur station

28-01-2019

at 01:15 Hrs

Failure of ‘R-phase’ HV side Current transformer (CT)

of 315MVA 400/230kV ICT-3 at 400kV

Sriperumbudur substation (400kV TANTRANSCO

switchyard).

1) TANTRANSCO to ensure proper legends for DR

Digital signals and all required events(including CB

status, Type of protection operated) are captured in

Event logger.

2) TANTRANSCO to extend BBP trip from BusBar

relay to 86A (with source-1 DC) in addition to 86B

(with source-2 DC), or to provide Common trip relay

96 with redundant DC supply.

3) TANTRANSCO to inform the action plan with

timelines for providing Numerical BBP at

Sriperumbdur SS .

4) TANTRANSCO to check the healthiness of all

CT’s in the stationand submit a report regarding the

same to SRPC to prevent any such occurrence in

future.

TANTRANSCO TANTRANSCO MAIL DATED 13.06.2019:

1. At present Duobias relay avaiable I/O configuration could not be carried out.after

changing the relay Digital signals will be configured

2.COMPLIED

3.Provision of Numerical BBP relay covered under R&M work. Tender under

progress.

4.out of 30 CTs, 21 No CTs have been replaced with new one.


1. , 3. Timeline requested upto July 2020.

2. Complied

4. Timeline requested upto September 2019.


1. At present Duobias relay avaiable I/O configuration could not be carried out.after

changing the relay Digital signals will be configured

2.COMPLIED

3.Provision of Numerical BBP relay covered under R&M work. Tender under

progress.

4.out of 30 CTs, 21 No CTs have been replaced with new one.

Pending

83/I/7 Complete outage of

230kV/110kV KR Thoppur

Substation of

TANTRANSCO

11-04-2019

at 13:16Hrs

Triggering incident was failure of Y-ph CT of Bus

Coupler at 230kV KR Thoppur(Salem) SS. Bus bar

protection of Bus-1 and Bus-2 operated resulting in the

tripping of all the connected elements at 230kV KR

Thoppur SS. 400kV/230kV ICT#1 and 2 at Salem also

got tripped during this event.

1.TANTRANSCO informed that replacement of

mechanical relay by Numerical relay is under progress

and it is recommended to submit the action plan

regarding the same with proper time-lines.

2.TANTRANSCO is also recommended to send

equipment failure report to CEA regarding failure of

Bus coupler CT.


1. Replacement of numerical relay under progress

2.Equipment failure report will be sent

Pending

Annexure-II

Page 40 of 48

83/II/13 230kV Bus dead at 230/110

kV Pugalur

14-03-2019 at

13:24 hrs

Triggering incident was R-phase breaker failure in

230kV Pugalur end of Budansandhai feeder. LBB

operated resulting in tripping of all connected elements.

As reported, 230kV side was on single bus operation

since bus sectionalizer provision is not there. 110kV

side connected feeders did not trip.

TANTRANSCO is recommended to furnish

equipment failure report to CEA regarding failure of

CB.


Equipment failure report will be sent

Pending

85/II/1 Tripping of 400/230kV

MANALI ICT-3

13-05-2019 at

2:42 hrs

ICT-3 got tripped on the activation of HV REF

protection. During test charging of 110 kV Manali-

ETPS -1 , the 110 kV ETPS -1 got tripped on the

activation of Back up relay and Distance relay failed to

act

1. TANTRANCO is recommended to sort out the

malfunctioning of ICT Ref protection in consultation

with OEM and submit a detailed report regarding the

same in 1 month time.

2. TANTRANSCO is recommended to ensure proper

labelling of all digital signals in Disturbance recorders

of lines and ICTs at Manali SS.

TANTRANSCO Yet to be informed Pending

85/III/6 400 KV Thiruvelam – Palavadi

line-1

28-05-2019 at 18:04

hrs

B-phase to earth fault. A/r attempt could not be validated. TANTRANSCO is recommended to check sending of DT from

Palvadi end during 3-ph trip at Palvadi. The time

synchronization issues between Thiruvalem and Palvadi shall

also be rectified.


85/IV/6 Tripping of 400kV Kayathar-

Kanarpatty line-1 & 2

10-06-2019 at 12:22

hrs

Line-1 & 2 tripped at Kanarpatty end due to spurious DT sent

from kayathar end. Feeder did not trip at Kayathar end

TANTRANSCO is recommended to submit a report regarding

the problem with PLCC panel at Kayathar along-with

Remedial Measures suggested by OEM.


Annexure-II

Page 41 of 48

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

Status received vide mail dated 12-12-2017:

1. Detailed engineering of the scheme has been completed. Material procurement is in

progress. ---Pending

2.,3. ---- Completed

4. The SOE and DR are available with time stamping from the numerical relays.

Hence stand alone event logger is not necessary ----- Completed

Status received vide mail dated 11-12-2018:

Work has been already tendered. It is expected that purchase process will completed


Sanction to issue purchase order in progress. Time Frame is January 2020 .

Review meeting on 27.06.2019.

1. BBP will be commissioned by December 2019.

2.,3.,4. Completed

79/I/1 Complete Outage of 220 kV

Idukki Power Station

01-10-2018 at

04:16 hrs

Triggering incident was R-Ph fault in 220kV Idukki-

Kalamassery line-2. R-phase pole of breaker didn’t

open at Idukki end. LBB of Bus-2 operated resulting in

tripping of all connected elements along with running

Unit#4 at Idukki and 50MVA station transformer. At

the same time, 220kV Idukki Kalamassery line-1 also

got tripped at Idukki end. Subsequently running Units 1

and 2 also tripped on Governor oil Low Pressure due to

loss of AC supply. This resulted in complete outage of

1). KSEBL to check & correct the LBB time setting

employed at their Idukki PH to 200 msec.

2). KSEBL o ensure that DR’s & EL’s of all

Protection Relays (PR’s) at their Idukki PH are

configured for recording all mandated protections &

signals.

KSEBL Status received vide mail dated 11-12-2018:

1) Present setting is 180ms.OEM(ABB) suggests that it will give around 200ms

delay as it is having inherent delay is of around 20ms(ie, 180ms +20ms

=200ms).With this setting the fault clearence is found after 220ms.So further revision

may be carried out after discussion.

2)Breaker status will be ready only after completing the GOOSE network as part of

renovation of all feeder panels and Idukki first stage units by June 2019 .

Pending

80/II/5 Multiple trippings at 220 kV

Madakathra station

15-10-2018 at

08:57 Hrs

Triggering incident was Y-phase to ground fault in

220kV Madakathra – Palakkad_KL (Ellapully) line

due to flashover of pilot insulator string. Auto-reclose

was successful at Madakathra end. At the same time

bus differential relay Zone-C mal-operated resulting in

tripping of all elements connected to the bus.

KSEBL to take steps to replace the existing static

(high impedance type) 220 kV BBP with numerical

Busbar protection at their 220 kV Madakathara SS.

KSEBL Status received vide mail dated 11-12-2018:

In progress


Status as on 18.03.2019: Estimate sanctioned by CE(Transmission North ) and have

prepared the technical specifications.Tendering procedures are yet to get started.


Pending

Kerala

PED

Triggering incident was conductor snapping in 110 kV

Kalamassery- Kaloor feeder

1. Time-frame?58/I/1

(GD)

KSEB 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

KSEB Pending23-08-2016

at 11:20 hrs


Kalamassery Substation

Annexure-II

Page 42 of 48

82/I/5 Complete Outage of 220kV

Bhramapuram substation of

KSEB

08-02-2019 at

10:28 hrs

Complete outage of 220kV Brahmapuram SS occurred

due to suspected mal operation of Bus Bar protection.

1) KSEBL to furnish detailed report regarding the

healthiness of BBP operation at 220kV Brahmapuram

after testing of the same on 12th April 2019.

2) KSEBL to submit the action plan regarding

(i) Replacing of the Static High impedance BBP

(using CRM relays) with Numerical BBP.

(ii) Replacement of CRM relays and relays with no

Disturbance recording facilitites.

KSEBL Status received vide mail dated 03.05.2019:

1) Detailed report sent on 02.05.2019…..Completed.

2) As reported earlier in this regard, the permanent solution to this problem is to

replace the existing high impedance static relay with a low impedance numerical

relay. The station authorities have already initiated action to implement the same by

June 2020.

Pending


Edamon SS of KSEB

27-05-2019 at

12:30 hr.

Triggering incident was three phase to earth fault in

220 kV Edamon Bus 1 and 2. Bus 1 and 2 Bus bar

protection operated resulting in the tripping of all

connected elements.

1.KSEBL may develop proper operational code for

procedures to be followed while performing operations

in switchyard and sensitize their operators to reduce

operational errors. 2.ksEBL to ensure time

synchronization of relays at 220 kV Edamon SS.

KSEBL KSEBL mail dated 30.07.2019:

1. proper operrational code is avilalable in 220kV SS Edamon

2. All 220KV relays of Edamon substation are synchronized with GPS clock . Out of

this, 3 relays are having hardware issues with time synchronisation switch . This

problem will be resolved by August 2019 itself.

Pending


Pothenkode Substation of

KSEB

04-07-2019

at 01:18 hrs

Triggering incident was failure of suspension insulator

of 220kV Pothenkode – Trivendrum ckt-2. Bus bar

protection of Bus-1 and Bus -2 operated resulting in

tripping of all connected elements.

1. KSEBL is recommended to investigate the non-

operation of zone selective Busbar Operation at 220/

110kV Pothencode SS and submit detailed report

regarding reasons for the same alongwith remedial

measures taken.

2. KSEBL is recommended to ensure time

synchronization of relays at 220/ 110kV Pothencode

SS.

KSEBL Yet to informed Pending

85/II/9 Tripping of 220KV Sabarigiri-

Theni line23-05-2019

at 16:12 hrs

Line tripped on operation of DEF at Theni end KSEBL is recommended to configure in DR and EL

the pick up and operation of relevant distance

protection zones in the event of distance protection

operation.

KSEBL Yet to informed Pending


1 at Khammam

27-01-2019

at 14:33hrs

ICT-1 at Khammam tripped on operation of IV side

non directional Over-current high set during failure of

L.A in 220kV Khammam (Budhidampadu)-Suryapet

line-2

PGCIL (SR-I) to immediately take necessary actions

to raise the Highset pick up current setting as per

protection standards since unwarranted tripping of ICT

for fault on 220kV line compromises the reliability of

Power system. In any case the transformer protection

should not encroach into protection zone of nearby

protection element.

PGCIL (SR-I) Review meeting on 27.06.2019:

PGCIL (SR-I) informed that the ICT high set settings have been sent by mail

Pending

84/II/3 Tripping of 400kV KTPS-

Khammam line

11-04-2019 at 13:59 hr.Line tripped on operation of overvoltage stage-1

protection at KTPS end and DT received at Khammam

end. Phase voltages at KTPS end could not be verified

from the DR furnished.

PGCIL (SR-I) to ensure time synchronization of DR

and EL at Khammam end.

PGCIl (SR-I) Yet to be informed Pending


2 at Bangalore (Somanahalli)

26-10-2018 at

12:10 Hrs

400/220 kV ICT-2 at Bengaluru (Sonamahalli) tripped

due to operation of LV side over flux protection which

in turn was due to suspected 220 kV CVT problem.

PGCIL (SR-II) to configure DR’s & EL’s all

protection relays at their 400/ 220 kV Somanahally SS

for all mandated protections and signals.

PGCIL (SR-II) Review meetinmg on 27.06.2019:

PGCIL (SR-II) was asked to furnish the status of implementation of the

recommendation at the earliest.

Pending

84/II/2 Tripping of 400kV

Somanahalli-Dharmapuri

line-2

07-04-2019 at

18:02 hr.

Line tripped on operation of over voltage stage-1

protection at Somanahalli. Somanahalli end DR: Vr-

240kV, Vy-253kV, Vb-241kV. Y-phase voltage was

higher than R and B phase

1. PGCIL (SR-II) to configure OVR start and OVR

trip signal in Event logger to facilitate verification of

adopted OVR grading.

2.PGCIL (SR-II) to ensure time synchronization of

DR and EL at Somanahalli end and Dharmapuri end.

PGCIL (SR-II) Yet to be informed Pending

84/II/15 Tripping of 400kV Bus-1

and connected elements at

400kV Bidadi substation

25-04-2019 at 08:01 hr.Triggering incident was failure of R-ph CB of bus

reactor at 400kV Bidadi. Bus bar protection of Bus-1

operated resulting in the tripping of all elements

connected to Bus-1

1. PGCIL (SR-II) was requested to send the

equipment failure report to CEA.

2.PGCIL (SR-II) is recommended to share the

feedback of OEM regarding decomposition of SF6 gas.


PGCIL (SR-I) & PGCIL (SR-II)

Annexure-II

Page 43 of 48

85/II/8 Tripping of 765/400kV ICT-

1 and 2 at Kurnool

substation

21-05-2019 at

18:11 hrs

ICT 1 and 2 got tripped due to maloperation of

Bucholz relays during the charging of 400KV Kurnool-

Nanoor line 1 which tripped on SOTF

PGCIL (SR-I) is recommended to submit a detailed

report regarding operation of Buchholz relay of 765/

400kV ICT 1& 2 during through fault after

consultation with OEM along-with the remedial

measures taken to prevent occurrence of any such

incidence in future.

PGCIL (SR-I) Yet to be informed Pending

85/II/16 Tripping of 400kV Tumkur-

Bidadi line-1&2, 400kV

Tumkur-Cuddapah line-2,

400kV Tumkur-Pavagada

line-2

29-05-2019 at

6:11 hrs

Lines tripped due to Y-N & Y-B phase to earth fault PGCIL (SR-2) is recommended to submit Equipment

failure report to CEA regarding the failed LA.


85/II/18 Tripping of 765/400kV ICT-

2 at Kurnool

02-06-2019 at

17:41 hrs

ICT-2 got tripped on operation of Back up directional

over current due to through fault (Y-B phase fault).

PGCIL (SR-1) is requested to check the operation of

ICT HV side High set O/C protection for through fault

and submit a report regarding the same.

PGCIL (SR-I) Yet to be informed Pending

85/III/7 Tripping of 400kV Pugalur-

Karaikudi line-1

31-05-2019 at

17:44 hrs


was successful at Karaikudi, At Pugalur end there was

3-phase trip

PGCIL (SR-2) is recommended to ensure proper

condition monitoring of their CB’s such as sufficient

air pressure.


Others

Annexure-II

Page 44 of 48


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 Review Meeting on 21.12.2018:

It was noted that no TPCIL representatives had come to attend the meeting

Review meetinmg on 27.06.2019:

No representative from the utility attended meeting and it is requested to submit status

regrading the recommendation at athe earliest.

Pending

02-04-2016 at

17:08 hrs


S.P.Koil Station of

TANTRANSCO

PendingNPCIL (MAPS) Status revided vide MAPS mail dated 06.12.2016;

1. The settings given by M/s TANTRANSCO were adopted for Main –I & Main- II

relays for both the lines. The same settings were verified to be same. Subsequently

calibrated was done and no drift was observed. --- Completed

2. From May 2016 onwards, the DR, EL and trip report are being sent by mail to

SRLDC, Bengaluru by MAPS. --- Completed

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

Annexure-II

Page 45 of 48

78/II/2 Tripping of 400 kV Neyveli

TS2Exp -Pugalur line

01-08-2018

at 11:56 hrs

Triggering incident was failure of R-ph tension

insulator string/ flashover in 400 kV Bus-1 at NLC

TS2Exp end. Busbar protection had operated resulting

in tripping of all main breakers connected to 400kV

Bus-1 at Neyveli TS2 Exp. In 400kV NLC TS2Exp -

Pugalur line, fault was sensed in Zone-1, R-N at

Pugalur end resulting in a single phase trip. Direct Trip

was received at Pugalur end due to operation of over

voltage Stg-2 at NLC TS2Exp.

1. NLCIL to furnish a report along with a suitable

SLD on the tripping event explaining the observed

discrepancies [DPR, Z1 operation, instantaneous

operation of OVR-II operation], and remedial action

taken to attend the same.

2. NLCIL to configure DR’s & EL’s of all protection

relays at their NLC TS-IIExp station for all mandated

protections & signals.

NLCIL Review Meeting on 21.12.2018:

NLCIL was asked to furnish the status of implementation of the recommendation

given at the earliest.




Pending

79/II/8 Tripping of 400 kV NLC TS-

2 (Exp) – Pugalur line

10-09-2018 at

20:57 hrs

Line tripped on B-N fault. Auto-reclose was not

attempted at Pugalur end due to DT receipt from NLC

TS2Exp end. At NLC TS2Exp end, V>2 trip was

observed in DR. Analog voltages recorded in DR were

observed to be less than that required for O/V Stage-II

operation.

NLCIL to furnish a detailed report on tripping event

explaining the observed discrepancies , and proper

reasons for tripping of the line considering both the

Main-relays including remedial action taken w.r.t.

healthiness/ replacement of Main protection relays on

400 kV NLC TS2Exp–Pugalur line.

NLCIL Review Meeting on 21.12.2018:

NLCIL was asked to furnish the status of implementation of the recommendation

given at the earliest.


it is requested to submit status regrading the recommendation at athe earliest.

Pending


PS – SGPL line-1

14-11-2018 at

20:20 hrs

Y- ph to earth fault occurred in line due to snapping of

GIS to Air bushing conductor at SGPL switchyard.

The conductor got grounded such that the fault was

being fed by NPS bus and there was earth fault and

broken conductor start at SGPL end. NPS end got

tripped in Zone-2 due to non-receipt of carrier resulting

in a 3-ph trip at NPS. After 500ms, earth fault

occurred at SGPL end resulting in Zone-1 operation

and 3 phase trip. A/R was not attempted at SGPL end

SGPL to examine the reasons for no-operation / failure

of Auto-reclosure from their end for the subject

tripping, and furnish an action taken report detailing

remedial measures taken to PCSC forum.

SGPL Review meetinmg on 27.06.2019:



Pending

80/III/6 Tripping of 400 kV Neyvelli

TS2 (Exp) - Pugalur line

07-11-2018 at

05:50 Hrs

400 kV Neyvelli TS2Exp - Pugalur tripped on

B-phase to ground fault due to DPR, Z1 operation.

Auto-reclose was successful at Pugalur end and the

line tripped at Neyveli TS2Exp end only. Auto-reclose

was not attempted at Neyveli TS-2(Exp) end

NLCIL to furnish a detailed report on the reasons for

A/R non-operation for the subject tripping at their

NLCTS2Exp station including remedial measures

taken to PCSC forum.

NLCIL Review meetinmg on 27.06.2019:



Pending


Kayamkulam –Punnapura-2

24-02-2019 at

03:05hrs

Line tripped on B-phase to earth fault. Auto-reclose

was successful at Punnapura. A/r was not attempted at

Kayamkulam and there was pole discrepancy operation

resulting in tripping of R and Y pole of CB.

It was noted that no representative of NTPC attended

the meeting.

NTPC (Kayamkulam) to furnish detailed report

regarding failure of Auto-reclosure at Kayamkulam

end for Kayamkulam –Punnapura line-2.

NTPC (KYKLM) Review meeting on 27.06.2019:




Trip report for Tripping of 220 kV Kayamkulam –Punnapura-2 submitted , but for

submitting detailed report for Auto-reclosure at Kayamkulam end not operating for

Kayamkulam –Punnapura line-2 , half day shutdown of Kayamkulam –Punnapura

line is required to check reason for failure . May please approve half day outage of

Kayamkulam –Punnapura line and intimate us atleast one day in advance.

Pending


Kayamkulam –Punnapura-2

05-03-2019 at

00:30hrs

220kV Kayamkulam-Punnapura -2 tripped on Zone-1

distance protection due to R-N fault. Auto reclose

operated and successful at Punnapara end but didnot

operate at Kayamkulam end.

It was noted that no representative of NTPC attended

the meeting.

NTPC (Kayamkulam) to furnish detailed report

regarding failure of Auto-reclosure at Kayamkulam

end for Kayamkulam –Punnapura line-2.

NTPC (KYKLM) Review meeting on 27.06.2019:




Trip report for Tripping of 220 kV Kayamkulam –Punnapura-2 submitted , but for

submitting detailed report for Auto-reclosure at Kayamkulam end not operating for

Kayamkulam –Punnapura line-2 , half day shutdown of Kayamkulam –Punnapura

line is required to check reason for failure . May please approve half day outage of

Kayamkulam –Punnapura line and intimate us atleast one day in advance.

Pending

Annexure-II

Page 46 of 48


NLC1

Expansion(NLC1EXP)

05-06-2019at 18:51 hr.Triggering incident was failure of Y-phase CT of GT-1 (Generator Transformer) at 400kV NLC1EXP. Bus-1 Bus bar protection operated resulting in the tripping of NLC1EXP U#1 and 400kV NLC1EXP- Nagapattinam line 1. NLCIL to check the healthiness of R & B ph CT of

Unit-1 at NLC TS1(Exp) and if found unhealthy

replace the same alongwith replacement of Y-ph CT.

CT replacement plan and timeframe shall be informed

to SRPC.

2.NLCIL in coordination with PGCIL(SR-II) to

resolve the time syncronisation issues in 230kV NLC

TS1(Exp) – Nagapattinam line.

3. NLCIL was also requested to investigate the reason

of unwarranted DT sent to NLC TS1 (Exp) end from

NLC TS2 end and resolve the same.

NLCIL NLCIL mail dated 09.07.2019:

AT TS2 Side Siemens 7SA52 & Micromho relay are used for distance protection.

During the incident Micromho has sensed the CT blast as a Zone-1 fault and tripped

the feeder. Adt signal was send to TS1 Exp end. The relay will be tested during the

next shut down.

Pending


Dichipally–Ramagundam

line

20-04-2019 at

18:09 hr.

Y phase to Earth fault in the line. Line did not auto-

reclose at Ramagundam end

1. It was noted that no representative of NTPC

(Ramagundam) attended the meeting.

2. NTPC (Ramagundam) to submit a detailed report

regarding non-operation of A/R at Ramagundam end

and Remedial measures taken for the same

NTPC (RMGDM) Yet to be informed Pending

84/II/20 Tripping of 400kV Neyveli

TS2- Neyveli TS-I (EXP)

and 400/230 kV ICT-1

atNeyvli

07-05-2019 at 20:56 hr.400kV/230kV ICT-1 got tripped on Differential

protection due to failure of R phase bushing on the HV

side. For 400kV Neyveli TS2- Neyveli TS-I (EXP), R

pole breaker at TS1Expgot tripped. TS2 End breaker

tripped on trip command received from TS1 EXP

1. NLCIL to measure the earth resistance of Neyveli

TS-2 SS and submit the same to PCSC forum. NLCIL

to check the healthiness of LAs of ICTs and confirm

proper earthing.

2.It is also recommended to furnish a report on

adequacy of ground wire shielding of switchyard.

3. NLCIL to ensure Time synchronization of relays at

Neyveli TS-2 SS.

NLCIL NLCIL mail dated 09.07.2019:

1) The earth pit resistance of the ICT1 LA was measured as follows.

400 kV side was measured on29-03-19

Rphase - 0.61 ῼ , Y phase - 0.76ῼ , B phase - 0.58 ῼ

230 kV side was measured on 29-03-2019

Rphase - 0.47 ῼ , Y phase - 0.86ῼ , B phase - 0.68ῼ

The resistive leakage current for the LA's was also measured and the readings are as

follows.

400kV side was measured on 29-03-2019 and the values are as follows .

R phase - 73 μA , Y phase 90 μA , B phase - 92 μA .

230kV side was measured on 22-03-2019 and the values are as follows

R phase - 238 μA , Y phase - 330 μA , B phase 401 μA.

After the incident on 07-05-19 the resistive leaksge current was again measured on

13-05-2019 and the values are as follows.

400kV Side

R phase - 91 μA , Y phase - 116 μA , B phase - 105 μA

230 kV side

R phase - 297 μA , Y phase - 318 μA , B phase - 385 μA

2) Time synchronization of one series of relays completed. The time synchronization

of balance relays will be completed by August 2019.

Pending

84/III/12 Tripping of 400 kV Simhadri-

Kalpakka line-3

12-05-2019 at

18:33 hr.

R-phase to earth fault. Line did not attempt auto-

reclose

1. It was noted that no representative of NTPC

(Simhadri) attended the meeting.

2.NTPC (Simhadri) to submit a detailed report

regarding non-operation of A/R at Simhadri end and

Remedial measures taken for the same.

NTPC(Simhadri) Yet to be informed Pending

85/II/19 Tripping of 400kV JSW-

Guttur line

02-06-2019 at

18:17 hrs

Line tripped due to OV St-1 protection operation at

JSW end and DT was sent to Guttur end. At Guttur

end B ph voltage was observed to be lesser comparing

to R ph and Y ph(Vr-249kV, Vy-255kV and Vb-

230kV).

JSWEL is recommended to monitor the B-ph CVT of

400kV JSWEL-Guttur line (due to lower B-ph voltage

compared to other two phases). The same shall be

replaced if the issue persists.

JSWEL Yet to be informed Pending

85/II/21 Tripping of 400kV JSW -

Guttur line and 400 kV

Kaiga - Guttur line-2

05-06-2019 at

18:27 hrs

Y-phase to earth fault occurred in 400kV Kaiga-Guttur

line-2. A/r was successful at Guttur end. At Kaiga end

A/r was not attempted and breakers got tripped due to

operation of Pole discrepancy (1.65 Sec). 400kV JSW-

Guttur line tripped on operation of over-voltage at

Guttur and direct trip was received at JSW. From DR

of Guttur, it is observed that there was swell in R & Y

phase voltage for few cycles

1. NPCIL (KGS) is recommended to identify the issue

related to unsuccessful A/R attempt of 400kV Kaiga –

Guttur line and non-opening of R-pole CB. It is

recommended to check the healthiness of all breakers

including breaker timing.

2. Time synchronization of DR and EL at Kaiga end

shall be ensured.

NPCIL (KGS) Yet to be informed Pending

Annexure-II

Page 47 of 48

85/III/14 Tripping of 400kV Kaiga-

Guttur line-2

16-06-2019 at

19:20 hrs

R-phase to earth fault. Auto-reclose attempt at Guttur

end was not successful as fault was persistent in

nature. Attempt for A/r could not be established from

Kaiga end EL

1. NPCIL (KGS) is recommended to identify the issue

related to unsuccessful A/R attempt of 400kV Kaiga –

Guttur line and non-opening of R-pole CB. It is

recommended to check the healthiness of all breakers

including breaker timing.

2. Time synchronization of DR and EL at Kaiga end

shall be ensured.

NPCIL (KGS) Yet to be informed Pending

85/IV/7 Tripping of 400kV

Ramadugu-Singareni line

11-06-2019 at

08:24 hrs

Line tripped due to Direct Trip receive at Ramadugu

end

Singareni STPP is recommended to submit a detailed

report regarding sending of DT from singareni end that

resulted in tripping of 400kV Ramadugu-Singareni

line.

Singareni TPP Yet to be informed Pending

Annexure-II

Page 48 of 48

Sl.No. Element Name Outage date/time Revival date/time Reason for outage Sender/ ReceiverRemedial Measures/ Actions

takenRemarks

1 400KV-BPS-TUMKUR-2 17-03-2019/16:17:00 R-Y FAULT KPTCL To-be-discussed

2 400KV/220KV RAMAGUNDAM-ICT-2 05-04-2019/19:56:00 05-04-2019/23:26:00BUS BAR PROTECTION

OPERATEDNTPC To-be-discussed

3 220kV Dindi-Srisailam line-2 17-05-2019/11:44:00 17-05-2019/16:33:00 TRIPPED ON R-N FAULT TSGENCO/ TSTRANSCO

"TSTRANSCO:

It is 220kV Dindi-Srisailam-2

feeder.

A/R successful at Dindi end."

4 400KV-BTPS-HIRIYUR-2 02-06-2019/18:16:00 TRIPPED ON Y-N FAULTKPCL/ KPTCL

[ Pending with KPTCL]

"KPCL: Line tripped on Zone-2,

""C"" phase to earth.

Remedial Measures: Line Charged

on 03.06.2019 at 09:47Hrs from

BTPS end

"

Status of A/R in the

line?

5 400KV-TALGUPPA-HASSAN-1 05-06-2019/23:59:00 06-06-2019/00:32:00R Phase distance

protection operatedKPTCL/ PGCIL (SR-II) To-be-discussed

6 132KV-KONAJE-MANJESWAR-1 06-06-2019/05:45:00EARTH FAULT RELAY

OPERATEDKPTCL/ KSEBL

KSEBL:

Feeder not trippped at

Manjeswar end

7 400KV-KUDGI_PG-NARENDRA-1 07-06-2019/22:47:00 07-06-2019/23:00:00 Y-N FAULT PGCIL(SR-II) To-be-discussed

8 400KV-DONI-GUTTUR-1 11-06-2019/17:24:00 11-06-2019/18:01:00BUS BAR PROTECTION

OPERATEDKPTCL To-be-discussed

9 400KV-GUTTUR-JINDAL-1 11-06-2019/17:24:00 11-06-2019/19:00:00BUS BAR PROTECTION

OPERATEDKPTCL/ JSWEL To-be-discussed

10 400KV-KAIGA-GUTTUR-1 11-06-2019/17:24:00 11-06-2019/20:13:00BUS BAR PROTECTION

OPERATEDNPCIL (KGS)/ KPTCL To-be-discussed

11 400KV-GUTTUR-HIRIYUR-1 11-06-2019/17:24:00 11-06-2019/18:35:00BUS BAR PROTECTION

OPERATEDKPTCL/ PGCIL (Sr-II) To-be-discussed

12 400KV-GUTTUR-HIRIYUR-2 11-06-2019/17:24:00 11-06-2019/18:42:00BUS BAR PROTECTION

OPERATEDKPTCL/ PGCIL (SR-II) To-be-discussed

Pending Remedial Measures/ Actions taken for the Critical Tripping Incidents (as on 19.08.2019)

Annexure-III

Page 1 of 5

13 400KV/220KV GUTTUR-ICT-1 11-06-2019/17:24:00 11-06-2019/18:10:00BUS BAR PROTECTION

OPERATEDKPTCL To-be-discussed

14 400KV/220KV GUTTUR-ICT-2 11-06-2019/17:24:00 11-06-2019/19:04:00BUS BAR PROTECTION

OPERATEDKPTCL

On 11.06.19 at 17:23 hrs 400KV

Kaiga-Guttur-1(Line-1) tripped at

Kaiga end on receipt of DT from

Guttur end. As per KPTCL

information, during ground fault

testing in bus bar panel at Guttur

end, trip command was extended

to bus bar protection and all

connected elements were

tripped. Direct trip was extended

to Kaiga end CB. No event is

recorded at Kaiga end. Kaiga-

Guttur-1 (Line-1) was taken into

service on 11.06.2019 at 20:13hrs

vide CPCC-06/234 and SRLDC -

06/627.

Issue is belonging to KPTCL

15 400KV-NELAMANGALA-TALGUPPA-1 12-06-2019/18:24:00 12-06-2019/20:44:00 EMERGENCY WORK KPTCL To-be-discussed

16 400KV-TALGUPPA-HASSAN-1 12-06-2019/14:38:00 12-06-2019/21:31:00INSULATOR FLASH

OVERKPTCL/ PGCIL (SR-II) To-be-discussed

17 400KV-GUTTUR-HIRIYUR-1 12-06-2019/17:00:00 12-06-2019/17:19:00DT received from

GutturKPTCL/ PGCIL (SR-II) To-be-discussed

18 400KV/220KV HOODY-ICT-2 16-06-2019/19:20:00 16-06-2019/20:51:00

OVER FLUX

PROTECTION RELAY

OPERATED

KPTCL To-be-discussed

19 400KV-KAIGA-GUTTUR-2 18-06-2019/02:53:00 R-N FAULT NPCIL(KGS)/ KPTCL To-be-discussed

20 220KV-AMBEWADI-XELDEM 23-06-2019/16:09:00 TRIPPED ON C-N FAULT KPTCL To-be-discussed

Annexure-III

Page 2 of 5

21 220KV-CHILLAKALLU-PULICHINTHALA-1 25-06-2019/17:17:00 25-06-2019/17:34:00 TRIPPED ON R-N FAULTAPTRANSCO/ TSGENCO

[ Pending with TSGENCO]

APTRANSCO: Feeder tripped on R-

Phase to ground, Zone-2 fault.

Line charged after taking

permission from SLDC. Fault

distance of 81.68KM falls in

TSTRANSCO juridiction.

TSTRANSCO: Line Patrolling done

and no fault found. Substation

belongs to TSGENCO

What protection

operated at TSGENCO

end?

22 400KV-BHADRAVATHI-RAMAGUNDAM-1 26-06-2019/16:29:00 26-06-2019/18:35:00 RELAY MALOPERATION NTPC (RMGD)/ WR To-be-discussed

23 400KV-SALEM-DHARMAPURI-1 29-06-2019/15:43:00 29-06-2019/17:03:00 phase to phase fault PGCIL (SR-II) To-be-discussed

24 220KV-Talapalli-NAGARJUNASAGAR TS 30-06-2019/11:03:00 30-06-2019/11:36:00 TRIPPED ON B-N FAULTAPTRANSCO/ TSGENCO

[ Pending with TSGENCO]

APTRANSCO: Feeder not tripped

at Tallapalli end.

APTRANSCO: The feeder

"Nagarjuna sagar-AP" may be

changed as "Tallapalli".

2.Feeder not tripped at Tallapalli

end.No carrier received from

Nagarjuna Sagar -TS end due to

PLCC problem at TSGENCO end.

25 132KV-KONAJE-MANJESWAR-1 07-07-2019/12:49:00 DISTANCE PROTECTION KPTCL/ KSEBLKSEBL: Supply failed at 110kV

Manjeswar substaion

26 400KV/110KV SHOLINGANALLUR-ICT-1 09-07-2019/14:47:00 09-07-2019/20:25:00TRIPPED ON BUCCHOLZ

RELAY OPERATIONTANTRANSCO To-be-discussed

27 132KV-KONAJE-MANJESWAR-1 14-07-2019/10:25:00 14-07-2019/10:49:00 TRIPPED ON B-N FAULT KPTCL/ KSEBL To-be-discussed

28 400KV-KAIGA-GUTTUR-2 22-07-2019/17:47:00TRIPPED DUE TO B-N

LINE FAULTNPCIL (KGS)/ KPTCL To-be-discussed

29 400KV-YELHANKA-NELAMANGALA-1 23-07-2019/12:09:00operation of gas

chamber protectionKPTCL/ PGCIL (Sr-2) To-be-discussed

30 220KV-KADAKOLA-KANIYAMPETTA 23-07-2019/10:49:00 23-07-2019/12:26:00 RELAY MALOPERATION KSEBL/ KPTCL To-be-discussed

31 400KV-HOODY-YELHANKA-1 23-07-2019/12:09:00operation of gas

chamber protectionKPTCL/ PGCIL (Sr-2) To-be-discussed

Annexure-III

Page 3 of 5

32400KV/110KV SUNGAVARACHATRAM-ICT-

326-07-2019/14:07:00 26-07-2019/15:15:00

EXTERNAL PROTECTION

TRIPTANTRANSCO To-be-discussed

33400KV/110KV SUNGAVARACHATRAM-ICT-

426-07-2019/14:10:00 26-07-2019/16:30:00

EXTERNAL PROTECTION

TRIPTANTRANSCO To-be-discussed

34 220KV-THENI-MOOZIYAR-1 27-07-2019/12:24:00 27-07-2019/12:47:00TRIPPED ON SINGLE

PHASE TO GND FAULTKSEBL/ TANTRANSCO To-be-discussed

35 400KV/220KV TALGUPPA-ICT-2 27-07-2019/16:27:00 27-07-2019/17:16:00MALFUNCTIONING OF

OCRKPTCL To-be-discussed

36 132KV-KONAJE-MANJESWAR-1 28-07-2019/10:29:00 28-07-2019/14:26:00 DISTANCE PROTECTION KSEBL/ KPTCL To-be-discussed

37 400KV-KRISHNAPATNAM-NELLORE_AP-1 01-08-2019/21:49:00 TRIPPED ON R-Y FAULT APGENCO/ APTRANSCO To-be-discussed

38 220KV-AMBEWADI-PONDA-2 02-08-2019/00:18:00 DISTANCE PROTECTION KPTCL/ GED To-be-discussed

39 400KV-NCTPS_STAGE_II-VALLUR-1 04-08-2019/22:19:00TRIPPED ON SINGLE

PHASE TO GND FAULTTANGEDCO/ NTECL To-be-discussed

40 400KV/230KV UDUMALPET-ICT-3 04-08-2019/10:34:00 04-08-2019/11:57:00

OVER FLUX

PROTECTION RELAY

OPERATED

PGCIL (SR-II) To-be-discussed

41 400KV-KALPAKKA-ASUPAKA-1 05-08-2019/13:37:00LA blast of Kalpaka -

Asupaka Line @KalpakaAPTRANSCO/ TSTRANSCO To-be-discussed

42 HVDC 500KV KOLAR_DC Pole 05-08-2019/10:14:00 05-08-2019/13:20:00EXTERNAL PROTECTION

TRIPPGCIl (Sr-II) To-be-discussed

43 400KV-GAZUWAKA-KALPAKKA-1 05-08-2019/13:37:00 05-08-2019/14:54:00LA blast of Kalpaka -

Asupaka Line @KalpakaPGCIL (SR-1)/ APTRANSCO To-be-discussed

44 400KV-KALPAKKA-SIMHADRI_STG1-2 05-08-2019/13:37:00 05-08-2019/14:38:00LA blast of Kalpaka -

Asupaka Line @Kalpaka

APTRANSCO/ NTPC

(SIMHADRI)To-be-discussed



APTRANSCO/ NTPC


46 220KV-ELAPULLY-PALAKKAD(KL)-3 05-08-2019/06:41:00 05-08-2019/18:33:00TRIPPED ON DISTANCE

PROTECTIONKSEBL To-be-discussed



APTRANSCO/ NTPC


48 400KV-NELAMANGALA-TALGUPPA-1 07-08-2019/19:31:00 220KV SIDE PROBLEM KPTCL To-be-discussed

49 132KV-KONAJE-MANJESWAR-1 08-08-2019/03:29:00 08-08-2019/03:49:00 Main supply failure KSEBL/ KPTCL To-be-discussed

Annexure-III

Page 4 of 5

50 132KV-KONAJE-MANJESWAR-1 09-08-2019/21:42:00 09-08-2019/22:37:00 transient fault KSEBL/ KPTCL To-be-discussed

51400KV-NCTPS_STAGE_II-

SUNGAVARACHATRAM10-08-2019/16:45:00 TRIPPED ON C-N FAULT TANGEDCO/ TANTRANSCO To-be-discussed

52 132KV-KONAJE-MANJESWAR-1 10-08-2019/10:47:00 10-08-2019/14:55:00 DISTANCE PROTECTION KPTCL/ KSEBL To-be-discussed

53 400KV/220KV NP_KUNTA-ICT-3 12-08-2019/12:08:00 12-08-2019/14:14:00Due to fault in 220KV

Galiveedu PS1 Line-2PGCIL (SR-1) To-be-discussed







57 400KV/230KV KARAIKUDI-ICT-3 15-08-2019/06:57:00 15-08-2019/08:58:00OIL SURGE RELAY

ACTEDPGCIl (Sr-II) To-be-discussed

58220KV-KOTHAGUDEM_TPS-

LOWER_SILERU-115-08-2019/13:04:00 15-08-2019/13:36:00 TRIPPED ON Y-N FAULT TSGENCO/ APGENCO To-be-discussed

59 220KV-CHILLAKALLU-NARKETPALLI-1 16-08-2019/22:57:00 16-08-2019/23:17:00 TRIPPED ON R-N FAULT APTRANSCO/ TSGENCO To-be-discussed

60 400KV-GOOTY-NELAMANGALA-1 17-08-2019/06:10:00 17-08-2019/06:47:00 DISTANCE PROTECTION PGCIL (SR-1)/ KPTCL To-be-discussed

61 230KV-NEYVELI_TS_II-KARAIKAL-1 17-08-2019/00:28:00 17-08-2019/02:03:00 DISTANCE PROTECTION NLCIL/ PGCIL (SR-2) To-be-discussed

Annexure-III

Page 5 of 5

Documents

· 2019-08-20 · Agenda for the 86th Meeting of PCSC scheduled to be held on 4th September, 2019 Page 2 4.2 Remedial measures for "Transmission Elements under Forced Outage" The