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.”
Agenda for 94th Meeting of PCSC scheduled to be held on 29th January, 2021 (online through WebEx) Page 2/4
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.
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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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 2/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 3/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 4/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 5/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 6/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 7/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 8/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 9/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 10/11
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
Grid Occurrences to be discussed in the 94th Meeting of PCSC scheduled to be held on 29th January 2021 11/11
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 .
Review Meeting dated 20.12.2018:
1. Tender would be floated in January 2019. Works would be completed in 6
months after awarding PO.
Review Meeting dated 27.06.2019:
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
Review Meeting dated 19.12.2017:
TSTRANSCO informed that the works are under progress, and are targeted to be
completed in 3 months time.
TSTRANSCO MAIL DATED 20.01.2018:
Line Differential Protection will be provided within 3 months i.e., by end of March,
2018.
TSTRANSCO MAIL DATED 20.04.2018:
Line Differential Protection relays are under procurement and will be provided by
end of May, 2018.
TSTRANSCO MAIL DATED 17.05.2018:
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.
TSTRANSCO MAIL DATED 12.10.2018:
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.
TSTRANSCO mail dated 30.10.2019:
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.
TSTRANSCO mail dated 18.01.2020:
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.
TSTRANSCO mail dated 28.11.2020:
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
Review Meeting dated 19.12.2017:
PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL
to complete procurement of LDP relays. To this, PCSC forum asked TPCIL to
submit written confirmation to PGCIL (SR-I) by 29.12.2017. PGCIL (SR-I)
assured that with receipt of above confirmation from TPCIL by Dec, 2017, they
would be able to complete the work by February, 2018.
APTRANSCO informed that they would be able to implement LDP from their &
APGENCO side by April, 2018.
In this regard, PCSC forum made it clear that the recommendation is about
providing LDP as both Main-I & Main-II relays on all stated lines in Nellore
Complex, ans asked all stakeholders to ensure & comply with the same.
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.
PGCIL (SR-I) mail dated 10.12.2018:
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.
PGCIL (SR-I) mail dated 20.12.2018:
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-I) mail dated 07.06.2019:
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.
PGCIL (SR-I) mail dated 30.10.2019:
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.
PGCIL -Sr-1 mail dated 17.12.2019:
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.
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.
Review Meeting dated 19.12.2017:
It was noted that the original Gooty - Lingapur line got LILOed at BTPS, Alipura,
and Ragulapadu. It was also noted that Phase Discrepancy is being observed in
Ragulapadu - Alipira section only. When enquired about the same, KPTCL
informed that they would examine the issue in detail, and would inform the action
lan proposed by next PCSC-71 meeting. On this, APTRANSCO was also asked to
render all help required from their side to KPTCL.
APTRANSCO maild 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.
APTRANSCO Mail Dated 25.07.2018:
To be attended by KPTCL as discussed in 75th PCSC meeting.
KPTCL mail dated 19.12.2018:
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.
APTRANSCO MAIL DATED 22.01.2019:
Pending [with KPTCL ]
Review Meeting on 27.06.2019:
KPTCL informed that the work is expected to be completed by August 2019.
KPTCL mail dated 12.02.2020:
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.
Review Meeting on 20.12.2018:
In view of Tiruvalam being inter-state sustation, TANTRANSCO was asked to
prvodie double-bus operation at their 230 kV Tiruvalam SS.
APTRANSCO MAIL DATED 22.01.2019:
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
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:
1. Bus segregation will be ensured by providing bus coupler bay by extending the
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
KPTCL mail dated 19.12.2018:
3). Nagzari-Bidnal PLCC link is healthy --- Completed.
1.--- Pending
2. --- Pending
Review Meeting on 20.12.2018:
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
KPCL mail dated 13.05.2019:
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.
KPCL mail dated 25.06.2019:
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.
KPCL mail dated 16.07.2019:
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. 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.
KPCL mail dated 30.10.2019:
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. 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.
KPCL mail dated 17.12.2019:
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. NIT issued through e-portal on 16.09.2019. Cover-1
opened on 02.12.2019. Technical evaluation is in progress.
KPCL mail dated 11.02.2020:
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. 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:
2) Replacement of existing PZ1000 relays with new version Numerical Line
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
Review Meeting on 20.12.2018:
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.
KPCL mail dated 23.01.2019:
1) It shall be reviewd and Implemented by KPCL in coordination with KPTCL.
2)....Completed.
KPCL mail dated 23.01.2019:
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.
Review Meeting on 27.06.2019:
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:
1) Letter addressed to KPTCL RT dated: 25.03.2019 for review and
implementation of SPS at NPH. Reply from KPTCL is awaited.
2)Completed.
KPTCL mail dated 12.02.2020:
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:
1) Letter addressed to KPTCL RT dated: 25.03.2019 for review and
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
APTRANSCO Mail Dated 18.12.2018:
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.
Review Meeting on 20.12.2018:
1 & 2). TANTRANSCO informed that Work will be completed by March 2019.
3. APTRANSCO informed that work will be completed by February 2019.
APTRANSCO MAIL DATED 22.01.2019:
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
TANTRANSCO MAIL DATED 19.03.2019:
New 230kV isolators have been allotted for replacement of defective isolators.
Hence time line requested upto June.2019.
TANTRANSCO MAIL DATED 13.06.2019:
1. New 230kV isolators have been allotted for replacement of defective isolators.
Hence time line requested upto Sep.2019.
Review Meeting on 27.06.2019:
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
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
TANTRANSCO mail dated 12.02.2020:
New 230kV isolators have been allotted for replacement of defective isolators.
Hence time line requested upto March 2020.
TANTRANSCO mail dated 20.05.2020 & 07.07.2020:
New 230kV isolators have been allotted for replacement of defective isolators.
Hence time line requested upto 31.12 2020.
TANTRANSCO mail dated 28.09.2020 & 11.11.2020:
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.
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:
1.Provision of bus coupler breaker is not feasible due to space constaint.
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:
1.Provision of bus coupler breaker is not feasible due to space constaint.
2&3. Tirunelveli end maintained by PGCIL.
4. Report sent to CEA. -- Completed
TANTRANSCO mail dated 28.09.2020:
1.Provision of bus coupler breaker is not feasible due to space constaint. - Dropped
2. & 3. PGCIL (Sr-2) to update
4. Completed
TANTRANSCO mail dated 11.11.2020:
1. 1.Provision of bus coupler breaker is not feasible due to space constaint.
2&3. Tirunelveli end maintained by PGCIL.
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
Review Meeting on 27.06.2019:
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.
KPTCL mail dated 12.02.2020:
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
TANTRANSCO mail dated 26.07.2019:
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.
TANTRANSCO mail dated 12.02.2020:
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
Complete outage of 230kV
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
Complete outage of 230kV
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 .
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. GPS commissioned
TANTRANSCO mail dated 28.09.2020:
1. complied .
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. 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.
TANTRANSCO mail dated 11.11.2020:
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. -- 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 •
TSTRANSCO mail dated 28.11.2020:
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)
Complete outage of 230kV
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.
TSTRANSCO mail dated 28.11.2020:
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.
• Cable got tripped on operation of Overcurrent
protection.
• At the same time, 220kV Pavagada KSPDCL line-3
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.
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.
• Cable got tripped on operation of Overcurrent
protection.
• At the same time, 220kV Pavagada KSPDCL line-3
got tripped only at Pavagada end on operation of
DEF protection.
i. PGCIL(SR-
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