· 2021. 1. 19. · bar protection operated at 220kV Nandihal station and all connected elements...

Agenda for 94th Meeting of PCSC scheduled to be held on 29th January, 2021 (online through WebEx) Page 1/4

Southern Regional Power Committee

Bengaluru

Agenda for 94th meeting of Protection Coordination Sub-Committee(PCSC) of SRPC

to be held on 29th January, 2021 through VC/Online

1. Introduction

2. Confirmation of Minutes of last PCSC meeting

Confirmation of minutes of 93rd Protection Coordination Sub-Committee meeting held on 2nd December 2020, issued vide letter No: SRPC/SE-III/PCSC-93/2020/ 50-87 dated 18th

January 2021. The minutes may be confirmed.

3. Grid Occurrences

3.1. Grid Disturbances (GD) and Grid Incidences (GI) occurred during the period

October - December, 2020, given at Annexure-I, would be discussed in the

meeting.

a) Constituents are requested to furnish the following information in respect of the above grid occurrences to have fruitful discussions: (i) Detailed analysis of the events (ii) SLD or equivalent pictorial representation clearly showing:

a. Location of fault with distance b. Fault details with type &relay indications c. CT/PT/CVT rating details with location d. Bus-bar arrangement/ Configuration of feeders e. CB positions (OPEN/ CLOSE) at the time of fault f. Isolator & Earth-switch positions (OPEN/CLOSE) g. Voltage, frequency & power flows with direction at the time of fault

(iii) Output of Event logger & Disturbance recorder (iv) Remedial Action(s) taken (v) Relay setting details

b) Constituents are requested to furnish full particulars of the tripping events pertaining to their system, preferably in the form of power point presentation, well in advance (latest by 26-01-2021) to the scheduled meeting date, to take up for discussion in the meeting.

c) Constituents are requested to present the fault analysis with clear diagrams and remedial actions taken for the trip events, in the meeting.

3.2 In compliance of Regulations 5.2 (r) of IEGC, which is given below:

“5.2 System Security Aspects

(r) All the Users, STU/SLDC and CTU shall send information/data including disturbance recorder/sequential event recorder output to RLDC within [24 hours]20 for purpose of analysis of any grid disturbance/event. No User, SLDC/STU or CTU shall block any data/information required by the RLDC and RPC for maintaining reliability and security of the grid and for analysis of an event.”


a) Constituents are required to furnish the following information in respect of Grid

Occurrences(GD/GI) within 24 hours of occurrence of the same to SRLDC/ SRPC: (i) First Information Report (FIR) (ii) Event Logger (EL) output (iii) Disturbance Recorder (DR) output (iv) Trip event analysis report-TR (with pre and post fault system conditions)

b) Non-furnishing of tripping details (FIR/DR/EL/TR) for the period 16.10.2020 –

31.12.2020 had been brought to Constituents’ notice vide the following SRPC letters:

(i) No. SRPC/ SE-III/ PCSC/ 2020/ 3035-54 dated 13.11.2020, (ii) No. SRPC/ SE-III/ PCSC/ 2020/ 3067-80 dated 23.11.2020, (iii) No. SRPC/ SE-III/ PCSC/ 2020/ 3154- 171 dated 09.12.2020, (iv)No. SRPC/ SE-III/ PCSC/ 2020/ dated 01.01.2020

c) Non-compliance in this regard would be discussed in the meeting.

4. Compliance by Constituents (Submitting status/remedial measures/certificate)

4.1. Status of implementation of Recommendations of PCSC-93

Status of implementations of recommendations of PCSC-93 shall be presented by constituents in the forthcoming PCSC.

4.2. Status of implementation of pending Recommendations previous PCSCs

a) The status of implementation of PCSC recommendations (up to 93rd PCSC meeting), which are pending, is at Annexure-II.

b) The latest status on the same may please be sent latest by 26.01.2021, to place the same before the sub-committee.

4.3. Remedial measures for "Transmission Elements under Forced Outage"

a) 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), to discuss the same.

b) The tripping events are based on the daily reports at SRLDC website https://www.srldc.in/DailyReport.aspx under the menu: Reports->Daily-> "TL under Forced Outage".

4.4. Certificate for Healthiness of Batteries

a) 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 RPCs, from their respective Constituents and furnish the same to CEA/ MoP.

b) 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.

c) The sought status for the month of October - December, 2020 is awaited from the following SR-Constituents:

https://www.srldc.in/DailyReport.aspx

Agenda for 94thMeetingof PCSC scheduled to be held on29th January, 2021 (onlinethrough WebEx) Page3/4

Month Utility Name

October 2020 TPCIL

November 2020 TPCIL

December 2020 APGENCO(Hydel), KPCL, KPTCL, KSEBL, NTPC(Simhadri), TPCIL

The non-reporting of status of healthiness of batteriesmay be discussed.

5. Protection Management system (PMS) project

a) Even though PMS project as a whole is yet to be operationalized, Protection Database Management System (PDMS) of PMS project, which hosts relay settings data of SR-Constituents, has been put into on-linemode so that Consittuents can cross-check the relay settings pertaining to their system, and get them corrected by appropriately taking up with the Project Implementation Agency (PIA). Similarly, Data Management Network System (DMNS), which acts as a medium to communicate changes in Protection Elements and Network Elements that take place in one’s system to PIA, has also been put into on-line mode so that Protection Database of PMS project is always kept up-to-date. In this regard, Constituents are requested to (i) complete verification of relay settings pertaining to their respective system uploaded in PDMS by the end of January, 2021, and (ii) regularly inform PIA regarding network modification and relay setting changes through DMNS in order to ensure that Protection Database of SR being modeled in PMS is kept up to date.

b) The latest PSCT database and Station SLDs were uploaded in ftp link and was communicated vide SRPC mail dated 18.01.2021. All Constituents were requested to download them and verify the features of PSCT software. All license holders (the Utility personnel responsible for carrying out various studies and to whom PSCT dongles had been given) were requested to focus on utilizing the PSCT software and to furnish deficiencies noticed, if any, or suggestions for improvements.

c) All SAT features of PMS project are close to beingcompleted and efforts are being made to operationalize (commencement of Go-Live) of the PMS project in February – March, 2021.

The status regarding PMS project would be discussed in the meeting.

6. Frequent tripping of 230kV KKNPP-TTPS (ADL31) line

a) The frequent tripping issue of 230KV KKNPP-Tuticorin line (ADL31) was discussed in 87th and 92ndPCSC meeting of SRPC. In subsequent SRPC¬PCSC meeting, TANTRANSCO had informed that all measures had been taken from their end to address the issue. Purchase order was placed for bird guards and insulator replacement.

b) It was also informed by TANTRANSCO that insulator has been replaced in 50% length of line and the remaining would also be replaced by March 2021. Similarly, bird guards and colored flags would also be placed in the affected areas.


c) However, NPCIL(KKNPP), vide letter dated 10.12.2020 informed, that during

December 2020 there have been 5 trippings in a span of just 6 days. The list of trippings since October 2020 is attached at Annexure-IV.

The issue of frequent tripping of the line would be discussed in meeting.

7. Frequent faults in Talcher-Kolar HVDC line

a) NTPC-Talcher, vide email dated 28.12.2020 (attached at Annexure-V), had informed that generating units at Talcher trip frequently due to blocking of Talcher-Kolar HVDC poles. They pointed out that since the implementation of SPS scheme, NTPC-Talcher Kaniha stage-II experienced numerous unit trippings and backing down on account of SPS operation of Talcher-Kolar HVDC line fault, for reasons not attributable to the station.

The issue would be discussed in meeting.

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

9. Sending Agenda items for the PCSC meetings

Itis 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 date of 95th meeting of PCSC will be decided in due course.

*****

Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 1/11

Grid Occurrences - 94

For all tripping events, Constituents are requested to kindly furnish the detailed analysis of the events along with SLD or equivalent pictorial representation clearly 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 along with records of Event loggers, Disturbance recorders. The constituents are also requested to submit presentation of the analysis which may be required to be presented by the constituents in the event of meeting being conducted through VC.

I. Details of Grid Disturbances:

Sl.

No.

Details of Event Date &Time Reason Generation Loss

(MW)

Load

Loss

(MW)

Category

1 Complete Outage of 220kV Sabarigi

GS of KSEB

01-Oct-20 18:06

Triggering incident was failure of R-phase CT connected to 220kV Sabaigiri - Edamon fedder-2. As reported LBB operated and all connected elements tripped at Sabarigiri end only resulting in complete outage of 220kV Sabarigiri station.

220 16 GD-1

2

Complete outage of 220/66kV KSPDCL SS-6

(Pavagada) of KSPDCL

06-Oct-20 14:05

Triggering incident was R -N fault in 66kV Feeder no-10 of KSPDCL SS-6. Feeder tripped on operation of Earth fault overcurrent protection. At the same time, 220kV Pavagada - Thirumani line-2 tripped only at Pavagada end on operation of Zone-1 distance protection. This resulted in complete outage of 220/66kV KSPDCL SS-6, since the only connected feeder tripped.

179 NIL GD-1

3 Complete outage

of 220kV Nandihal, Bijapur and Indi SS

17-Oct-20 22:35

Triggering incident was failure of Y Phase Metering CT connected to GM Navara – Nandihal line-1. Bus bar protection operated at 220kV Nandihal station and all connected elements tripped. There was supply failure at 220kV Indi and Bijapur stations, since these station are radially fed from 220kV Nandihal station.

68 52 GD-1

4

Complete outage of 220kV Jurala

station of TSGENCO

31-Oct--20 04:23

Triggering incident was jumper cut in 220kV Jurala-Veltoor line. At the same time 220kV Lower Jurala- Veltoor, 220kV Lower Jurala- Jurala lines-1, 2 & 3 tripped. Running units at Jurala tripped due to loss of

20 NIL GD-1

Annexure-I


evacuating lines resulting in complete outage of Jurala station.

5 Complete outage

of 220kV Narendra station of KPTCL

31-Oct-20 23:47

Triggering incident was CT Blast in Bus-coupler Bay at 220kV Narendra SS. All connected elements at 220kV Narendra station tripped on Bus bar protection resulting in complete outage of the station.

NIL 40 GD-1

6

Complete Outage of 220kV VSS and 220kV Parawada

SS of APTRANSCO:

07-Nov-20 16:06

Triggering incident was failure of R-Ph LA of 220KV VSS-Gajuwaka_AP line. Due to non-tripping of line at 220kV VSS end, fault was cleared by tripping of all connected elements at remote end. This resulted in complete loss of supply at 220kV VSS. Since 220kV Parawada was radially fed from 220kV VSS, there was complete loss of supply at 220kV Parawada SS.

NIL 153 GD-1

7 Complete Outage of 230kV Betam

Wind Energy

12-Nov-20 12:03

Triggering incident was tripping of 230kV Betam - TTGS Line on operation of OV st-1 protection at Betam end. Due to tripping of the only connected line, there was complete loss of supply at 230kV Betam Wind Energy resulting in wind generation loss of 42MW.

42 NIL GD-1

8 Complete Outage of 230kV MAPS of

NPCIL

13-Nov-20 03:09

As per the information received, all connected lines tripped at 230kV MAPS due to BBP operation resulting in complete loss of supply.

210 NIL GD-1

9

Complete Outage of 230kV

Checkanurani SS of TANTRANSCO

16-Nov-20 13:25

Triggering incident was failure of R phase CB limb of 230kV Checkanurani- Nallamanayakkan Patti line at Checkanurani end. LBB of 230kV Checkanurani –Nallamanayakkan Patti line operated at 230kV Checkanurani end resulting in the operation of Bus-1 BBP. Due to this, all connected elements at 230kV Checkanurani SS tripped, since all the elements were connected only to Bus-1 during antecedent conditions.

NIL NIL GD-1

Annexure-I


10

Complete Outage of 220kV

Kalamasserry SS of KSEB

17-Nov-20 12:41

During antecedent condition, due to outage of 220kV Kalamasserry - Idukki line-1 and 2, 220kV Kalamasserry SS was radially fed from 400kV/220kV Kochi_PG SS and flows in 220kV Kochi_PG - Kalamasserry line-1 and 2 were around 195MW each respectively. As per the report submitted, triggering incident was B phase to Earth fault in 220kV Kochi_PG -Kalamasserry line-1. After the tripping of 220kV Kochi_PG -Kalamasserry line-1, 220kV Kochi_PG - Kalamasserry line-2 got overloaded. 220kV Kochi_PG -Kalamasserry line-2 tripped on operation of DEF protection as per IDMT curve at Kochi_PG end and was holding at Kalamasserry end.

NIL 390 GD-1

11 Complete Outage of 230kV BHAVINI

25-Nov-20 22:53

As per the information received, all connected lines tripped only at Bhavini end due to Over voltage resulting in complete loss of supply. Details are awaited.

NIL 70 GD-1

12 Complete Outage of 220kV Kadra PH

of KPCL

02-Dec-20 14:01

Zone-1 distance protection of 220kV Kadra - Kaiga line operated at 220kV Kadra end and LBB operated since the line was under NFBC during antecedent condition. Due to operation of LBB protection, all the elements connected to Bus-1 tripped at 220kV Kadra. Since all the elements were connected only to Bus-1 during antecedent condition, there was complete loss of supply. There was no generation at Kadra during this event.

NIL 39 GD-1

13

Complete Outage of 400kV SPIC Energy Power

Corporation (SEPC)

05-Dec-20 02:48

As per the information received, connected 400kV lines tripped on operation of OV St-1 protection resulting in complete loss of supply at 400kV SEPC.

NIL 1.5 GD-1

14 Complete Outage

of 400kV NLC2 Expansion

08-Dec-20 07:52

400kV NLC2 Expansion - NLC TS2 line was under outage during antecedent conditions due to CT and breaker failure at NLC TS2 end. Triggering incident was tripping of 400kV NLC2 Expansion -Pugalur line at Pugalur end on DT Receipt. Due to tripping of only connected

190 NIL GD-1

Annexure-I


400kV line, there was complete loss of supply at 400kV NLC2 Expansion and this resulted in a generation loss of 190MW.

15

Complete Outage of 230kV/110kV

Villianur SS of Pondy

09-Dec-20 09:20

Triggering incident was spurious tripping of 230kV/110kV 100MVA transformer-1 at Villianur SS on WTI (Winding Temperature Trip). At the same time 230kV Villianur connected lines and bus coupler tripped on operation of LBB protection resulting in the complete loss of supply at 230kV Villianur SS. 230kV/110kV 100MVA transformer-2 at Villianur SS was under outage during antecedent conditions.

NIL 54 GI-1

16

Complete Outage of 230kV/110kV

Bahour SS of Pondy

31-Dec-20 08:23

Triggering incident was ph-ph fault in 230kV Bahour - Karaikal line. At the same time, 230kV Bahour -Pondy line also tripped on operation of distance protection. Due to tripping of both incoming lines, there was complete loss of supply at 230kV Bahour SS.

NIL 80 GD-1

II. Details of Grid Incidents:

Sl.

No.

Details of Event Date &Time Reason Generation Loss

(MW)

Load

Loss

(MW)

Category

1 Tripping of 220kV

Regulapadu- Alipur Line

01-Oct-20 14:07

Line tripped only at Alipur end while interchanging the phase sequence (online) from RYB to BRY.

- - -

2 Multiple Tripping

at 400kV Vijayawada SS

03-Oct-20 14:04

As per the report submitted, triggering incident was R phase to Earth fault in 400kV Vijayawada - Sattenapalli line. At Vijayawada end, Zone-2 carrier aided protection operated and at Sattenapalli end, Zone-1 distance protection operated. A/r operated at both the ends and line tripped due to persistent fault. At the same time, 400kV Vijayawada VTPS IV line-2 tripped only at Vijayawada end due to suspected maloperation of Main-2 distance protection and the same needs review.

- - -

Annexure-I


3 Tripping of HVDC Gazuwaka Pole-1

and Pole-2

06-Oct-20 18:13

As reported, Pole-1 tripped on Station Inter-zone protection due to South side CW30Q50 Bay Y-Ph CT blast at Gazuwaka. Pole 2 Tripped on activation of Protective Y Block due to disturbance in Inverter side due to sustained commutation failure.

400 NIL GI-2

4

Tripping of Srisailam Right

Bank-Nagarjunasagar TS-

1

07-Oct-20 10:37

Triggering incident was R-phase to ground fault in the line at a distance of 0.2 km. from Srisailam end due to SRC insulator flashover. Line tripped on Zone-1 distance protection at Srisailam end and Zone-2, distance protection at Nagarjunsagar end. Auto reclose in the line is not in service since the line connects two generating stations. Non operation of Z2 carrier aided protection at N'sagar end needs review.

- - -

01-Dec-20 09:20

5

Tripping of 230kV Bus-1 at 400/

230kV Tirunelveli station of PGCIL

12-Oct-20 13:45

Triggering incident was Y-B phase fault in 230kV Tirunelveli - Udayathur line. LBB of 230kV Bis-1 at Tirunelveli station operated due to breaker stuck position resulting in tripping of all Bus-1 connected elements.

NIL NIL GI-1

6 Tripping of

400/230 kV ICT-1 at Udumalpet

14-Oct-20 03:49

As per the report submitted, ICT tripped due to suspected maloperation of PRV protection due to contact failure in the device.

- - -

7 Tripping of 400kV

Dhoni - Guttur Line 17-Oct-20

16:12

As per the report submitted, line tripped only at Dhoni end on operation of CTD while replacing CB panel DC source-2 fuses and the same needs review.

- - -

8 Tripping of

400/220 kV ICT-1 at Raichur

21-Oct-20 15:09

As per the report submitted, ICT#1 at RTPS tripped due to suspected maloperation of Buccholz protection and the same needs review.

- - -

9 Tripping of

400/220 kV ICT-3 at Trichur

25-Oct-20 15:17

As reported, 400/220kV ICT-3 at Trichur tripped on operation of 86 A Trip relay along with tripping of 110kV Madakathara - Vallappad feeder due to insulator decapping.

- - -

10 Multiple Tripping in 400/230/110kV

Kamuthi SS

25-Oct-20 07:07

As per the report submitted, triggering incident was inadvertent opening of 230kV bus coupler at 06:03Hr. ICT-1 (400/230KV), ICT-

- - -

Annexure-I


2(400/230KV) & ICT-4(400/110KV) tripped at 6.18Hr. and ICT-3 (400/110KV) tripped at 7.02Hr. and ICT-5(400/110KV) tripped at 7.07Hr. due to over flux protection. Tripping needs review.

11 Tripping of

400/230 kV ICT-3 at S'PUDUR

28-Oct-20 08:07

As reported 400/220kV ICT-3 at Sriperumbudur tripped on operation of B-phase unit PRV auxiliary protection due to problem in the PRV. It was also reported that there was no oil spurt out observed in the PRV.

- - -

16-Nov-20 10:13

As per the report submitted, ICT#3 at Sriperumbudur tripped due to operation of B phase PRV protection and the same needs review. As reported there was no oil spurt out observed in the PRV during the incident.

12 Tripping of

400/220 kV ICT-3 at Malkaram

28-Oct-20 11:29

As reported, LC of bus-1 for general maintenance works was availed on the day of the event. While testing of metering circuit of ICT-4 bay, trip signal was extended by mistake to Malkaram ICT-3, resulting in tripping of the ICT.

- - -

13

Tripping of 400/230kV ICT#2

at Thiruvallam

01-Nov-20 10:57

ICT#2 and 400kV Alamathy -Thiruvalam line-2 are in the same dia at 400kV Thiruvalam end. During antecedent conditions, Main breaker of ICT#2 at Thiruvalam end was under outage due to CT replacement works. Triggering incident was R phase to Earth fault in 400kV Alamathy -Thiruvalam line-2. A/r operated successfully at both the ends and line was holding. At Thiruvalam end, A/r of main breaker only operated and tie breaker tripped. Due to tripping of tie breaker at Thiruvalm end, ICT#2 also tripped.

- - -

01-Nov-20 12:17

02-Nov-20 11:32

ICT#2 and 400kV Alamathy - Thiruvalam line-2 are in the same dia at 400kV Thiruvalam end. As per the report submitted, during antecedent conditions, Main breaker of ICT#2 at Thiruvalam end was under outage due to CT replacement works. Triggering incident was R phase to Earth fault

- - -

Annexure-I


in 400kV Alamathy - Thiruvalam line-2. Fault was sensed in Zone-1 at both the ends. A/r operated successfully at both the ends and line tripped due to persistent fault. At Thiruvalam end, A/r tie breaker did not operate. Due to tripping of tie breaker at Thiruvalam end, ICT#2 also tripped.

25-Nov-20 21:26

ICT#2 and 400kV Alamathy -Thiruvalam line-2 are in the same dia at 400kV Thiruvalam end. As per the report submitted, during antecedent conditions, Main breaker of ICT#2 at Thiruvalam end was under outage due to CT replacement works. Triggering incident was operation of OV Stage-1 protection at Alamathy end and DT was received at Tiruvalam end. On receiving DT at Thiruvalam end, ICT#2 also tripped due to tripping of tie breaker. As per the DR analysis, Voltages observed at Alamathy end are Vr-251kV: Vy-251kV. Tripping needs review.

- - -

14

Tripping of 220kV Bus-1 and Bus-2 at

Nellore SS of APTRANSCO

02-Nov-20 22:27

As per the information received, 220kV Bus-1 and Bus-2 BBP operated resulting in the tripping of all connected elements at 220kV Nellore SS. 400kV/220kV ICT#1, 2 and 3 at Nellore also tripped during this event.

NIL 128 GI-1

15 Tripping of

400/220kV ICT-4 at Shankarpally

07-Nov-20 11:47

As per the report submitted, ICT#4 at Shankarapalli tripped due to suspected maloperation of PRV protection due to moisture ingress and the same needs review.

- - -

16 Tripping of 400 kV

BTPS-JSW Toranagallu

08-Nov-20 21:45

As per the report submitted, line tripped on operation of OV St-1 protection operated at BTPS end and DT was received at JSW end. As per the DR of BTPS end, voltages observed are: Vr-242kV, Vy-239kV and Vb-235kV. Since the voltages at BTPS end are within limits, operation of OV St-1 protection at BTPS end needs review.

- - -

17 Tripping of Bus-1

at 220kV Narsapur 10-Nov-20

01:13 Triggering incident was failure of Y-Phase Suspension Insulator

NIL NIL GI-1

Annexure-I


SS of TSTRANSCO string on LV side of Narsapur ICT-1 near 220kV Bus-1. Bus-1 BBP operated resulting in the tripping of all the elements connected to Bus-1 at 220kV Narsapur SS.

18

Tripping of 400/220 kV ICT-3

at Hoody

13-Nov-20 15:02

As per the report submitted, triggering incident was failure of 4CX25sqmm Copper Cable running from battery charger (in the control room) to DCDB panel in Kiosk No.7. This resulted in DC current leakage and CB opened. No load was affected as 500MVA ICT1 & ICT3 are in parallel. Tripping needs review.

- - -

19 Tripping of 400kV

Kalpakka Gazuwaka Line-1

13-Nov-20 11:12

As per the report submitted, triggering incident was fault in 400kV KV Kota Hinduja line. 400kV Kalpakka - Gazuwaka line tripped only at Gazuwaka end due to suspected mal operation of Main-2 (Schneider make P546 type) SoTF function and the same needs review.

- - -

16-Nov-20 12:17

20

Tripping of 220kV Bus-2 at Srisailam

Right Bank of APGENCO

16-Nov-20 20:26

Triggering incident was failure of CB of U#5 at Srisailam RB. LBB operated resulting in the tripping of all the elements connected to Bus-2 at Srisailam RB. There was no generation at Srisailam LB during antecedent conditions.

NIL NIL GI-1

21 Tripping of

400/230 kV ICT-2 at Pugalur

17-Nov-20 17:27

As reported 400/230kV ICT-2 at Pugalur tripped on operation of Buchholtz relay.

- - -

22 Tripping of

400/230 kV ICT-1 and 2 at Madurai

17-Nov-20 16:23

Suspected tripping of 400/230 kV ICT-1 and 2 at Madurai due to testing of 230kV BBP scheme. However, as per the information furnished by TANTRANSCO, leads of all bays were disconnected prior to testing. Hence there is no possibility to extend the trip signal. Tripping needs review.

- - -

23 Tripping of Bus-1

at 230kV Trichy TN SS of TANTRANSCO

17-Nov-20 00:01

Triggering incident was BN fault in 230kV Trichy TN - Alandur line-1. Due to non-opening of breaker at 230kV Trichy TN end, LBB operated resulting in the tripping of all the elements connected to Bus-1 at 230kV Trichy TN SS.

NIL NIL GI-1

Annexure-I


24 Tripping of 400 kV Vemagiri - GMR 2

21-Nov-20 11:34

As per the report submitted, DT was received at Vemagiri end and line tripped only at this end. At GMR end because of maloperation of main-1 relay DT was sent and line was holding at this end.

- - -

25 Tripping of

400kV/220kV Julurupadu-ICT-1

26-Nov-20 16:02

As per the report submitted, triggering incident was DC earth leakage in the cable connected from DC Distribution board to Transformer. Because of this LV side CB tripped. Tripping needs review.

- - -

26

Tripping of 220kV Bus-2 at

Shankarapalli SS of TSTRANSCO

26-Nov-20 07:57

Triggering incident was failure of R phase CB of 220kV Shanakarapalli -Parigi line-1 at Shanakarapalli end. LBB operated resulting in the tripping of all the elements connected to Bus-2 at Shankarapalli SS.

NIL NIL GI-1

27 Tripping of 400 kV Srisailam - Dindi -1

28-Nov-20 17:21

As per the report submitted, triggering incident was receipt of DT signal at Dindi end, because of Relay maloperation at Srisailam end. Line tripped only at Dindi end.

- - -

28

Multiple Tripping at 400kV Jindal TPS

of JSWEL and 400kV BTPS of

KPCL

29-Nov-20 13:16

Units 1,3,4 and 5 at Jindal TPS (780 MW) tripped due to flash over in GIS Chamber and Units#1 and 2 at BTPS (906 MW) tripped due to electrical side problem. Complete Generation loss of 1690 MW. 400kV Jindal – BTPS, 400kV Jindal – BPS -1, 400kV Jindal – Guttur and 400kV BTPS – Hiriyur -1 also tripped during this event.

1690 NIL GI-2

29

Tripping of 220kV-Talapally -

Nagarjunasagar_TS-3

01-Dec-20 15:45

As per the report submitted, triggering incident was PT fuse failure at N'sagar end. Line tripped only at N'sagar end and was holding at Tallapally end

-

-

-

03-Dec-20 21:30

As per the report submitted, triggering incident was R-N fault in the line. Line tripped only at N'sagar end because of suspected maloperation of DEF protection. Tripping needs review.

06-Dec-20 20:00

As per the report submitted, triggering incident was R-N fault in the line. Line tripped only at N'sagar end because of suspected

Annexure-I


maloperation of DEF protection and the same needs review.

20-Dec-20 21:25

As per the report submitted, triggering incident was R-N fault in the line. At N’sagar end, DEF operated and line tripped only at this end. Line was holding at Tallapally end. Tripping needs review.

23-Dec-20 00:16

As per the report submitted, triggering incident was R-N fault in the line.DEF operated at N’sagar end and the line tripped only at this end. Line was holding at Tallapally end. Tripping needs review.

30 Multiple Tripping

in 400kV Gajwel SS of TSTRANSCO

02-Dec-20 03:07

As per the report submitted, triggering incident was Y-N fault in 400kV Gajwel-Narsapur line. Fault was sensed in zone-1 protection at Narsapur end and carrier aided zone-2 protection operated at Gajwel end. A/R operated and successful at both the ends. At the same time, 400KV Gajwel-Narsapur-1 line tripped at Gajwel end only on suspected maloperation of SOTF and the same needs review.

- - -

31 Tripping of

400/220 kV ICT-1 at Dichpally

04-Dec-20 15:42

As per the report submitted, 400kV/220kV ICT#1 at Dichipalli tripped on operation of Differential protection due to testing of tie CT (same dia) wiring by MRT wing. Tripping needs review.

- - -

32 Multiple Tripping

at 220kV Sabarigiri GS

04-Dec-20 18:10

As per the report submitted, triggering incident was 3 phase fault in the line at a distance of 3.4kM from Sabarigiri end. At Sabarigiri end, Zone-1 distance protection operated and resulted in 3 phase trip. At Theni end, Zone-2 distance protection operated and resulted in 3 phase trip. Non operation on carrier aided protection needs review. Tripping of unit -5 needs review.

- - -

33

Tripping of

400KV/110KV Thennampatty-ICT

- 3

07-Dec-20 03:56

As per the report submitted, triggering incident was operation of PRV-2 trip protection due to heavy rain. Tripping needs review.

- - -

Annexure-I


34

Tripping of 400kV Bus-1 and Bus-2 at 400kV/230kV NLC

TS-2 Generating Station

07-Dec-20 18:59

Triggering incident was Yph Bus Coupler CT failure at 400kV NLC TS-2. 400kV Bus-1 and Bus-2 BBP operated resulting in the tripping of all the connected elements. 230kV bus was intact during this event.

300 NIL GI-2

35

Tripping of 220kV Bus-1 at

400kV/220kV Guttur SS of KPTCL

16-Dec-20 10:17

Triggering incident was BN fault in 220kV Guttur - Jogihalli line. Due to non-opening of B pole CB at 220kV Guttur end, LBB operated resulting in the tripping of all the elements connected to Bus-1 at 220kV Guttur SS. It may be noted that all elements were connected to 220kV Bus-1 at Guttur SS during antecedent due to CB replacement works. 400kV Guttur - Kaiga line-2 and 400kV/220kV ICT#1 at Kaiga also tripped during this event.

NIL NIL GI-1

36

Tripping of HVDC Talcher Kolar Pole-

1 and Multiple Tripping at 400kV

Kolar SS

20-Dec-20 21:25

Pole-1 of HVDC Talcher-Kolar tripped due to problem in valve cooling system at Talcher end. ESOF was received at Kolar end. After the tripping of Pole-1, rise in 400kV Kolar voltage was observed and all connected 400kV lines at Kolar except 400kV Kolar - Hoody line-1 tripped on operation of OV St-1 protection at Kolar end and DT was received at remote ends.

-

635MW

(SPS operation)

-

***

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)

Status of Pending Implementation of PCSC Recommendations as on 18.01.2021 (up to 93rd Meeting)

KPTCL Mail dated 27-05-2015:

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

Pending

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

--- Pending

3. --- Pending

KPTCL Mail dated 29-07-2015:

1. Initial Tendering stage. --- Pending

2. --- Pending

3. --- Pending

KPTCL Mail dated on 23-01-2016:

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

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

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

3. --- Pending

PGCIL (SR-I) Mail dated 14.07.2016:

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

Commettee recomendations and implemented" --- Completed.

KPTCL Mail dated 16.12.2017:

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

Pending

Review Meeting dated 19.12.2017:

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

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

Commissioning is targeted by January, 2019

--- Pending

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

Completed.

KPTCL mail dated 19.12.2018:

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

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


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

months after awarding PO.


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

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

Annexure-II

Page 1 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 TSTRANSCO MAIL DATED 22.01.2019:

Relays will be commissioned by end of February, 2019.

TSTRANSCO mail dated 22.06.2019:

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

2019.


LDP relays are available but commissioned was not done bue to non availability of

carrier communication cable and will be done in 2 months i.e., by December, 2019.


LDP relays are available at site. carrier communication cable laying between the

LDPs is procured and laying work is under progress and will be completed by end

of January,2020.

Commissioning of LDPs will be done by 2nd week of February, 2020.


2. Still the telecom communication cable laying is under progress and will be

completed by December 2020. After completion of cable laying, commissioning of

LDPs will be done. --- Pending

66/ II/

10

Tripping of 400/ 220 kV

ICT’s – 3 & 4 at

Ramagundam STPS

NTPC-Ramagundam/ TSTRANSCO PendingTriggering incident was failure of 220 kV

B-phase LA in ICT-3 LV extension feeder (220KV

line-2) at Malayalapalli substation

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

Ramagundam STPS.

2. NTPC/ TSTRANSCO to provide Line Differential Protection (with or without

pilot) on 220 kV Ramagundam – Malayalapalli lines – 1 & 2 & 3.

11-06-2017

at 19:46hrs

Annexure-II

Page 2 of 48


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

to complete procurement of LDP relays. To this, PCSC forum asked TPCIL to

submit written confirmation to PGCIL (SR-I) by 29.12.2017. PGCIL (SR-I)

assured that with receipt of above confirmation from TPCIL by Dec, 2017, they

would be able to complete the work by February, 2018.

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

APGENCO side by April, 2018.

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

providing LDP as both Main-I & Main-II relays on all stated lines in Nellore

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

PGCIL (SR-I) mail dated 20.06.2018:

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

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

week.


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

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

Review Meeting on 20.12.2018 & 27.06.2019:PGCIL (Sr-1) mail dated 31.10.2019:

Retrofitting works completed in NPS-NCC-1&2, NPS-Nellore-1&2 Main-1 relay,

NPS-TPCIL-1&2 lines completed.

Confirmation for retrofitting of Main-2 relay in NPS-Nellore-1&2 lines to be

received from SRPC. Presently both lines are bypassed at Nellore Bus-1&2 and

connected to Tiruvalam SS by closing Tie CBs at Nellore end. Now lines are long

lines as 400kV NPS-Tiruvalam-1&2. The same was discussed in 84th PCSC

meeting. SRPC has to give concurrence.

PGCIL -SR-1 maild ated 17.12.2019:

Retrofitting works completed in NPS-NCC-1&2, NPS-TPCIL-1&2 lines for both

Main-1&2 relays. Issue to be closed

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...

APTRANSCO Mail Dated 18.12.2018:

1) Bays and lines pertains to PGCIL .

2) ---Completed.


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

completed by Jan'2019.

APTRANSCO MAIL DATED 22.01.2019:

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.




management is seeking approval for the same. You are requested to takeup this

LDP issue in next TCC meeting.

PGCIL -Sr-1 mail dated 17.12.2019:



management is seeking approval for the same.

SRPC/PCSC may please allow the POWERGRID to book the expenditure in any

ongoing/upcoming projects.

PCSC on 18.12.2019:

PCSC forum decided to forward the issue to SRPC TCC meeting

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

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

ends.

Complete outage of 400kV

TPCIL station

69/I/2

02-10-2017 at

02:03 hrs

Tripping of 400 kV

Kurnool(PG) –

Kurnool(AP) line-2

69/III/3

TPCIL/

PGCIL (SR-I)

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.

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

30-10-2017 at

21:37 hrs

Pending [With

TPCIL]

Pending [with

PGCIL (SR-I)]

APTRANSCO/

PGCIL (SR-I)

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.

Annexure-II

Page 3 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.


Correction is to be incorporated in the primary side, procurement of required

materials under progress.

69/III/7 Tripping of 220 kV

Ragulapadu – Alipura line

12-10-2017 at

01:30 hrs

76/II/9 Tripping of 230 kV

Thiruvalam - Chittoor line

TANTRANSCO/ APTRANSCO13-06-2018 at

18:55hrs

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

successful at Regulapadu and breakers at Alipura

end got tripped.

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 ]

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

Tiruvalam end, breaker was under lockout leading to

operation of LBB protection.

KPTCL and APTRANSCO to sort out issues relating to incongruence in denoting

R, Y, B phases of the electric supply on their respective sides.

APTRANSCO/ KPTCL

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:


existing Bus.Time line 31.12.2019.

TANTRANSCO mail dated 12.02.2020 & 20.05.2020 15.06.2020 & 07.07.2020

& 28.09.2020:


existing Bus.Time line rquested upto 31.12.2020.

TANTRANSCO mail dated 11.11.2020:

Due to inadequate space,it is not fesible to provide hybrid BC breaker.

Pending [with

TANTRANSCO]

Annexure-II

Page 4 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

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

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.


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.


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


NLDC for DPR is awaited. NIT issued through e-portal on 16.09.2019. Pre-bid

meeting was held on 10.10.2019. Finalising of replies to pre-bid queries is in

progress.




NLDC for DPR is awaited. NIT issued through e-portal on 16.09.2019. Cover-1

opened on 02.12.2019. Technical evaluation is in progress.




NLDC for DPR is awaited. NIT issued through e-portal on 16.09.2019. Tender

evaluation is in progress.

KPCL mail dated 21.05.2020 & 27.07.2020 & 28.09.2020 & 26.11.2020:


protection relays having IEC61850 is included in PSDF Phase-II DPR. NIT issued

through e-portal on 16.09.2019. Tender evaluation is completed. Approval of

NLDC for DPR is awaited for placing PO on L1 agency.

KPCL/ 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.

17-09-2018 at

14:37hrs

Complete outage of 220 kV

Nagjheri PH and 220/110

kV Ambewadi Substation.

78/I/2 Pending

Annexure-II

Page 5 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 & 30.10.2019:

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 and 17.12.2019 and 11.02.2020:


implementation of SPS at NPH. Reply from KPTCL is awaited.

2)Completed.


The logic is being reviewed by SRLDC by conducting system studies for the

changed network configuration.

KPTCL mail dated 21.05.2020 & 27.07.2020 & 28.09.2020 & 26.11.2020:


implementation 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.

TANTRANSCO MAIL DATED 23.01.2019:APTRANSCO mail dated 15.03.2019:

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


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

Hence time line requested upto Sep.2019

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.

KPTCL/ KPCL Pending

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.

05-10-2018 at

00:42 hrs

Complete outage of 230/

110 kV Gummidipoondi

Substation

Pending [with

TANTRANSCO]

79/I/2

78/II/16 Multiple trippings at 220kV

Nagjheri PH

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.

1)KPTCL to examine the reasons for tripping of more than one Unit (Units – 3 &

6) on SPS operation at Nagjheri PH during subject trippings, and furnish a report

on the same along with remedial action taken to PCSC forum.

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

protection for the GT of Unit-2 at their Nagjheri PH.

31-08-2018

at 11:49 hrs

TANTRANSCO/ APTRANSCO

Annexure-II

Page 6 of 48



Hence time line requested upto March 2020.



Hence time line requested upto 31.12 2020.


Programmed to rectify / replace the sluggish 230kV Isolators in the bus coupler

breaker and double bus operation will be bring into service before 31.12.2020.


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, 12.02.2020 & 20.05.2020 &

15.06.2020:



4. Report sent to CEA. -- Completed


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

2. & 3. PGCIL (Sr-2) to update

4. Completed


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


4. Report sent to CEA. -- Completed

83/I/6 Complete outage of 220kV

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

KPCL mail dated 16.07.2019 & 30.10.2019:

1. under progress

2. Completed

KPCL mail dated 17.12.2019 and 11.02.2020 & 21.05.2020 & 27.07.2020 &

28.09.2020 & 26.11.2020:

1) To be furnished by KPTCL

2)Completed.


The logic is being reviewed by SRLDC by conducting system studies for the

changed network configuration

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)

Review meeting on 27.06.2019:

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

syncronisation has to be attended by KPTCL.

Pending


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.


1. LBB wiring set right and operation of the same has been verified for its

healthiness. -- Completed

2. Since the CBs and the Control & Relay Panels (CRP) are very old and

commissioned during 1993. The Distance relays even though are numerical due to

ageing its display and resetting keys are faulty. Hence it is proposed to replace the

CBs & CRPs with new CBs and Protection relay panel with SAS. A.R will be put

into service after replacing the CB & CRP.

3. Time synchronisation of Protection relays is being carried out . The work is

under progress.

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.

05-10-2018 at

00:42 hrs

Complete outage of 230/

110 kV Gummidipoondi

Substation


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.

Pending [with

TANTRANSCO]

79/I/2 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

Pending[PGCIL-

SR-II]

TANTRANSCO/ PGCIL (Sr-2)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.

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.

11-03-2019

at 00:55Hrs


Veeranam substation of

TANTRANSCO

83/I/1

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/ TANTRANSCO84/I/1

TANTRANSCO/ APTRANSCO

Annexure-II

Page 7 of 48

TANTRANSCO mail dated 20.05.2020 & 15.06.2020

1. complied .






3. GPS commissioned


1. complied .






3. GPS commissioned

4. TANGEDCO to reply - Pending

TANGEDCO mail dated 11.11.2020:

4. House Load operations are available in all the 3 units of NCTPS - 1 .

Generators can able to supply their own auxiliary load alone during this period and

they can be synchronised to the grid when the situation is

stable. But due to sudden change in turbine and boiler parameters

house load operation could not be possible at all times (Old Turbine and Boiler

control logic). (Feeders in Bus-Section I & II are already in tripped condition and

the whole generation is fed through Bus-Section - III , due to the tripping of this,

load evacuation problem got arise and consequent Unit tripping are happened) -

Complied

Note: 1) On that day Unit - II is in house load for 7 Mins, Unit - I is in house load

for 1 Min and then both the units are hand tripped due to un controlled turbine and

boiler parameters.

2) Unit-III turbine got tripped due to overspeed.






into service after replacing the CB & CRP. -- Pending

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

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.

APTRANSCO in coordination with TSTRANSCO to ensure frequent patrolling

and proper maintenance of ROW by attending all tree clearance issues.

APGENCO/ TSGENCO/ TSTRANSCO/ APTRANSCO APGENCO informed vide mail dated 26.05.2020 that The tine maintenance is

under the purviewof AP TRANSCO & TS TRANSCO . Most of the tripping fault

dista nce are under the coverage of TS TRANSCO •


Recently the line is made LILO at 400/220kV Asupaka susbstation. The tripping

details are already being submitted and only few trippings are under TSTRANSCO

jurisdiction. Frequent patrolling is being carried out at TSTRANSCO end.

Pending

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.

For the subject line, the following shall be carried out 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 TANTRANSCO mail dated 12.02.2020:

The PLCC link between 230KV Theni – Moozhiyar feeder is healthy condition and

non-actuation of Carrier Protection during the fault on 29-05-2019 at 18:39 Hrs

was due to the fault sensed in Zone-2 reach at Theni SS and Earth fault at

Moozhiyar SS.

KSEBL mail dated 11.02.2020:

PLCC system in SBTN feeder at Sabarigiri is not working well. Purchase process

for the new panel is under progress.It will be commissioned by April 2020.

TANTRANSCO vide mail dated 20.05.2020 informed that:

ZIV make new carrier set is erected and ready for commissioning . KSEB may

procure the same make ( ZIV) the link will be commissioned.

Pending [ with

KSEBL]

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 APTRANSCO maild ated 03.10.2019:

1. Equipment (LA failure) Failure report submitted to CEA on 12.07.19.

---Completed

2. Pending

Pending

86/II/7 Tripping of 220 kV KTPS -

Lower Sileru-1

8-7-2019 at

10:45 hrs

Line tripped on B-phase to earth fault. As per FIR,

there was zone-2 operation at KTPS

For the subject line, the following shall be carried out by APGENCO in

coordination with TSGENCO:

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 .

APTRANSCO APGENCO mail dated 26.05.2020:

Aulo Re closure is disabled due to generating station . Carried aided protection

extended from relay to PLCC panel is checked and found ok. The PLCC equipment

is under the purview of APTRANSCO, tit is kept in OFF condition at both ends. It

was mentioned that the same will be kept in service in short time as the 220kV

Lower Sileru KTPS feeder becoming LILO at 400 KV Asupaka sub-Station.

Pending (with APTRANSCO)


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.

Pending1.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/ TANTRANSCO84/I/1

Annexure-II

Page 8 of 48

88/IV/4 Tripping of 220kV Chillakallu

Suryapet line-1

17-10-2019 at 13:30

Hr.

Triggering incident was Y phase to B phase fault in the line. At

Chillakallu end, as per the report submitted it is mentioned that

Zone-1 distance protection operated. However, DR is not

available to verify the same. At Suryapet end, Zone-2 distance

protection operated and carrier was not received. Failure of

carrier aided protection at Suryapet end needs review.

The following shall be carried out by TSTRANSCO in coordination with APTRANSCO:

a) End-to-end testing for DT/ permissive & other signals may be ensured by testing at both the

ends.

b) Healthiness of PLCC system components (hardware and software) at both the ends to be

checked and faulty components to be repaired/ replaced.

c) Time synchronization of relays at both ends.

TSTRANSCO,/ APTRANSCO TSTRANSCO mail dated 11.02..2020:

At our end MRT & Telecom wing are ready to carry out end to end testing.

Waiting for confirmation from APTRANSCO end to carry out testing.


a) & b) End to end testing is carried out and A/R function is kept into service.

Pending Time sync??

89/I/6 Complete loss of supply at 220

kV Kolar, 220 kVMalur and 220

kV Sarjapur stations.

16-01-2020 at

09:58 Hr.

• Triggering incident was Y-phase jumper cut in 220

kV Kolar (KAR) – Kolar (PG) line-1.

• 220 kV Kolar (KAR) – Kolar (PG) Line-2 tripped

at Kolar (KAR) end only.

• There was complete loss of supply at 220 kV Kolar,

Malur and Sarjapur stations.

i. PGCIL (SR-2) to disable Broken conductor trip and enable Broken conductor alarm.

ii. KPTCL to configure all DR digital channels in relay DR and submit the SPS scheme

implemented at 220 kV Kolar (KAR) SS.

PGCIL (Sr-2)/ KPTCL KPTCL mail dated 22.05.2020:

2. Logic implemented for SPS provided at 220kV Kolar Sub station is already

mailed to SRPC/SRLDC

Pending DR configuration and broken

conductor trip?

90/II/17 Tripping of 400kV Guttur

–Hiriyur Line-215-03-2020 at

18:03Hr.

Line tripped on operation of OV St-1 protection

operation at Hiriyur end and was holding at Guttur

end. From DR of Hiriyur end, voltages observed are:

Vr-251kV, Vy-248kV and Vb-248kV. Non tripping

of line at Guttur end needs review.

PGCIL-SR-2 to configure DR and EL at Hiriyur end for the subject line for DT send and DT

receive signal.

For the subject line, the following shall be carried out by PGCIL-SR-2 in coordination with

KPTCL and revert back to the forum:

i. End-to-end testing for DT/ permissive& other signals to 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.

PGCIL (SR-2)/ KPTCL KPTCL mail dated 04.08.2020:

End to end testing is yet to be carried out.

Pending

90/V/1 220kV KTPS-Lower Sileru line-1

and 220kV KTPS V- Lower

Sileru line-2

10 -02-2020 at

11:34 Hr.

05-03-2020 at

12:00 Hr.

07-03-2020 at

13:25 Hr.

11-03-2020 at

15:01 Hr.

15-03-2020 at

12:04 Hr.

18-03-2020 at

12:25 Hr.

22-03-2020 at

10:50 Hr.

08-02-2020 at

12:35 Hr.

15 -02-2020 at

13:29 Hr.

16-02-2020 at

11:54 Hr.

22-03-2020 at

11:16 Hr.

27-03-2020 at

V. Frequent tripping of 220kV KTPS-Lower Sileru

line-1 and 220kV KTPS V- Lower Sileru line-2

during February 2020 to April 2020.

ATRANSCO in coordination with TSTRANSCO to ensure frequent patrolling and proper

maintenance of ROW by attending all tree clearance issues.

APTRANSCO/ TSTRANSCO TSTRANSCO mail dated 28.11.2020:

KTS-LSL is made LILO at Asupaka SS.

Frequent patrolling is being carried out from TSTRANSCO end.

Pending

90/VI/1 Tripping of 220kV KTPS –

Nunna line05-03-2020 at

13:44 Hr.

06-04-2020 at

13:39 Hr.

08-04-2020 at

16:53 Hr

10-04-2020 at

08:28 Hr

11-04-2020 at

15:03 Hr

18-04-2020 at

15:50 Hr

Frequent Tripping of 220kV KTPS – Nunna line

during February 2020 to April 2020

ATRANSCO in coordination with TSTRANSCO to ensure frequent patrolling and proper

maintenance of ROW by attending all tree clearance issues.

APTRANSCO/ TSTRANSCO TSTRANSCO mail dated 28.11.2020:

Frequent patrolling is being carried out from TSTRANSCO end.

Pending

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.

For the subject line, the following shall be carried out by TANTRANSCO in

coordination with KSEBL:

(iii) End-to-end testing for DT/ permissive & other signals may be ensured by

testing at both the ends.

(iv) Healthiness of PLCC system components ( hardware and software) at both

the ends shall be checked and faulty components shall be repaired/ replaced .

KSEBL/ TANTRANSCO TANTRANSCO mail dated 12.02.2020:

Carrier set healthy at Udumelpet end. Healthiness of link will be checked after

getting confirmation from KSEB

KSEBL mail dated 11.02.2020:

PLCC system in IDUD feeder at Idukki is not working well. Purchase process for

the new panel is under progress.It will be commissioned by April 2020.

TANTRANSCO vide mail dated 20.05.2020 informed that:

ZIV make new carrier set is erected and ready for commissioning . KSEB may

procure the same make ( ZIV) the link will be commissioned.

Pending [ with

KSEBL]

Annexure-II

Page 9 of 48

91/I/1 Complete outage of 220kV

Gowribidanur SS and

220kV KIADB SS of

KPTCL

04-04-2020 at

14:15 Hrs

• Triggering incident was R - Y fault in 220kV

Gowribidanur - KIADB line.

• At 220kV Gowribidanur end, fault was sensed in

Zone-2 and breaker didnot open because of

suspected breaker struck conditionand due to

absence of LBB/BBP protection at 220kV

Gowribidanur end, fault was cleared by tripping of

all the lines connected to 220kV Gowribidanur SS at

remote ends on operation of Zone-3 distance

protection.

• This resulted in complete loss of supply at 220kV

Gowribidanur SS.

• Since 220kV KIABD SS was radially fed 220kV

Gowribidanur SS, this further resulted in complete

loss of supply at 220kV KIADB SS.

i. PGCIL(SR-2) to submit a report detailing reason for delayed pick up of fault at

Hiriyur end, non-picking of fault by Main-1 relay of Gauribidanur line-1, and to

configure zone pick up and trip in 220kV lines from 400/ 220kV Hiriyur SS.

ii. KPTCL to expedite commissioning of BBP at 220kV Gauribidanur SS and

ensure time synchronization of relays at Madhugiri SS.

PGCIL(SR-2)/ KPTCL KPTCL mail dated 28.09.2020:

ii. 220kV Bus Bar Protection commissioned at Gowribidanur SS on 19.09.2020

Pending

91/II/1 Tripping of 220kV-

PAVAGADA-KSPDCL line-

4

04-04-2020 at

08:46Hrs

• Triggering incident was Y N fault in 33kV cable

no.3 of KSPDCL 220/33kV SS-4.

• Cable got tripped on operation of Overcurrent

protection.

• At the same time, 220kV Pavagada KSPDCL line-4

got tripped only at Pavagada end on operation of

DEF protection.

i. PGCIL(SR-2) to intimate PCSC forum regarding OEM observations and RM

suggested regarding DEF operation by Main-2 Siemens relay at Pavagada end.

ii. KSPDCL to check PLCC and investigate the reason for non-receipt of DT at

their end. Time synchronisation of relays with GPS clock at KSPDCL SS need to

be ensured.

PGCIL(Sr-2)/ KSPDCL Yet to be informed Pending

91/II/3 Multiple Tripping of 400kV

lines at Raichur(PG) SS

07-04-2020 at

19:04 Hrs

• Triggering incident was B phase LA failure at

Raichur(PG) end of 400kV Gooty-Raichur(PG) line-

1.

• 400kV Raichur TPS - Raichur(PG) line-1 &2 and

400kV Gooty-Raichur (PG) line-2 got tripped on

operation of Overvoltage ST-2 protection at

Raichur(PG) end and DT was sent to remote end.

• Running units#5 and 7 at 400kV RTPS got tripped

during this event.

i. PGCIL(SR-1) to evaluate the transient performance of CVTs at Raichur PG.

Time sync of DR with GPS at 400kV RaichurPG end for 400kV

400kVRaichurTPS-Raichur(PG) line-1 shall be ensured.

ii. KPCL to look into tripping of their HT equipment on negative phase sequence

current protection and to enable the same with sufficient time delay.

iii. KPCL is also recommended to trigger DR at 400kV RTPS GS during DT

receipt.

PGCIL(SR-1)/ KPCL KPCL mail dated 26.11.2020:

i) Pending

ii) Sufficient time delays for NPS protection is adopted based on OEM

recommendations for HT equipments. This point may be dropped -- Completed

iii) It will be configured during next shut down of lines. -- Pending

Pending

91/II/5 Tripping of 220kV-

PAVAGADA-KSPDCL line-

3

19-04-2020 at

15:23Hrs

• Triggering incident was B N fault in 33kV cable of

KSPDCL 220/33kV SS-3.


protection.



DEF protection.

i. PGCIL(SR-2) to intimate PCSC forum regarding OEM observations and RM

suggested regarding DEF operation by Main-2 Siemens relay at Pavagada end.

ii. KSPDCL to check PLCC and investigate the reason for non-receipt of DT at

their end.

iii. Time synchronisation of relays with GPS clock at KSPDCL SS need to be

ensured.

PGCIL(Sr-2)/ KSPDCL Yet to be informed Pending

91/II/13 Multiple Tripping in

220kV/33kV KSPDCL SS 4

09-05-2020 at

19:08Hrs

• Triggering incident was B ph Bus-2 PT failure at

220kV KSPDCL SS no.4.

• Bus-2 BBP operated resulting in the tripping of all

the elements connected to Bus-2 at 220kV KSPDCL

SS no.4.

• At the same time, RYBG fault occurred at 33kV

cable feeder no.6 of KSPDCL 220/33kV SS-3.


protection.



DEF protection.

i. PGCIL(SR-

· 2021. 1. 19. · bar protection operated at 220kV Nandihal station and all connected elements...

Documents

Transcript of · 2021. 1. 19. · bar protection operated at 220kV Nandihal station and all connected elements...