SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

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4 SOUTHERN REGIONAL POWER COMMITTEE BENGALURU Agenda for the 75 th Meeting of Protection Coordination Sub-Committee of SRPC to be held on 28 th June, Introduction 2. Confirmation of Minutes of last PCSC meeting Confirmation of minutes of 74 th Protection Coordination Sub-Committee meeting held on Grid Occurrences 3.1 Grid Disturbances (GD), Grid Incidences (GI), and trippings due to failure of Autoreclosing (A/R), and mal-operation of PLCC equipment that occurred during the period May-June, 2018 given at Annexure-I would be discussed in the PCSC meeting. Constituents are requested to furnish the following information in respect of the above grid occurrences to have fruitful discussions. (a) Single line diagram of the station with switching devices, CT, PT and relay details. (b) Cause of the tripping & Remedial Action taken (c) Relay setting details Constituents are requested to bring/ furnish full particulars of the tripping events pertaining to their system. 3.2 In compliance of Regulations 5.2 (r) of IEGC, the Constituents are required to furnish the following information in respect of Grid Occurrences within 24 of occurrence of the same to SRLDC/ SRPC: (a) First Information Report (FIR) (b) Event Logger (EL) output (c) Disturbance Recorder (DR) output (d) Trip event analysis report (with pre and post fault system conditions) Non-furnishing of tripping details (FIR/DR/EL/TR) for the period had been brought to Constituents notice vide letters (i) No. SRPC/ SE-III/ PCSC/ 2018/ dated , (ii) No. SRPC/ SE-III/ PCSC/ 2018/ dated Non-compliance in this regard would be discussed in the meeting. 4. Submission of Reports/ Compliance by Constituents 4.1 Status of implementation of pending Protection Coordination Sub-Committee (PCSC) Recommendations The status of implementation of pending PCSC recommendations (up to 74 th PCSC meeting) is given at. The latest status on the same may please be sent latest by Agenda for the 75 th Meeting of PCSC scheduled to be held on 28 th June, 2018 Page 1

5 4.2 Remedial measures for "Transmission Elements under Forced Outage" The Constituents are requested to furnish the remedial measures/ action taken by them for the tripping events as circulated vide our s. (I) The tripping events are based on the daily reports at SRLDC website under the menu: Reports->Daily-> "TL under Forced Outage") 4.3 Certificate for Healthiness of Batteries As per the MoP direction given in pursuant to recommendations of the Enquiry Committee (NEW grid disturbance on 30 th & 31 st July, 2012), RPC s are required to obtain from their respective Constituents the monthly certificate for healthiness of batteries, installed at 220 KV and above voltage level Substations (for power supply to Relays, RTUs and PLCC equipment) and furnish the same to CEA/ MoP. With reference to above, the Constituents have been requested to submit the certificate on healthiness of batteries on monthly basis (i.e. status for a month shall be sent by the 7 th day of the following month) to SRPC Secretariat. The sought status for the months of May, 2018 is awaited from the following SR-Constituents: TSGENCO (Hydro & Thermal), KPTCL, TANGEDCO, Puducherry, NLCIL, UPCL & JSWEL 5. Revision of Special Protection Scheme (SPS) implemented at UPCL s plant at Udupi Based on the deliberations in PCSC-65, PCSC-66, PCSC-68 and PCSC-69 meetings, the SPS at UPCL s Udupi plant was modified as given below for implementation: Agenda for the 75 th Meeting of PCSC scheduled to be held on 28 th June, 2018 Page 2

6 However, UPCL vide their mails dated & has sought to incorporate few changes as mentioned below, and requested to approve the same: 2 x 600 MW Units of UPCL has outlets via two 400 kv lines to Hassan and two 220 kv lines to Kemar via two ICTs of 315 MVA each. Till recently, around 65% of the ex-bus generation at UPCL was off-loaded on 400 kv Network to Hassan, and the remaining 35% via 220 kv lines to Kemar. However, since March, 2018 it was observed that loading on 220 kv UPCL-Kemar lines had been substantially higher, bordering thermal ratings of the conductor since March, There had also been corresponding overloading of ICTs, operating sometimes very close to be rated MVA capacity of the transformers and beyond. With Loadings on 220kV lines to Kemar remaining high, possibility of complete isolation of 220 kv side of the UPCL switchyard remains high in case of tripping of one of the 220kV Lines. But since neither the generating units be subjected to frequent backing down actions, nor the power system equipment be subjected to conditions leading to potential failures, the existing SPS has been reviewed with respect to overloading of 220 kv lines. Accordingly, it is proposed to include Stage-2 for (i) ICT overloading from 400 kv side in Contingency-2 & Contingency-3, and (ii) Overloading of any 220 kv line in Contingency-4 as mentioned below: Agenda for the 75 th Meeting of PCSC scheduled to be held on 28 th June, 2018 Page 3

7 The above proposal of UPCL would be discussed in the meeting. UPCL, SRLDC, and SLDC (KPTCL) are requested to put forth their views. 6. Using Data Modification Notification System (DMNS) of PMS Project DMNS is a system primarily aimed at bridging the gap between Utility Users and Data Modeling Team (DMT). It enables Utility Users to communicate to DMT about any changes (additions/ modifications) in Network Elements (Buses/ Generators/ Generator Transformers/ Transmission lines/ Cables/ Inter-connecting Transformers/ Reactors/ Capacitors/ etc.) and/ or Protection Elements (Relays, CT s, PT s/ CVT s, Breakers, and Isolators, etc.), and ensures that requests raised are duly processed. A brief on using various features of DMNS will be illustrated. 7. Submission of PMS Data by the Utilities of Tamil Nadu & Kerala You are kindly aware that as part of PMS project data collection by physical field visits of the stations in Tamil Nadu, Puducherry, and Kerala has been undertaken by PRDC. Even though this process has been completed, all the data sought as per stipulated formats for modeling them in PMS has been pending from certain stations. As informed by PRDC, even though they have been religiously pursuing (for past few months) with the concerned Constituents/ Personnel to obtain pending data, the progress has not been on the expected lines. In this regard, the pending data details from the stations in Tamil Nadu and Kerala are enclosed at Annexure-IV for kind reference. It is requested from all concerned Nodal Officers of Utilities of Tamil Nadu & Kerala to take steps to ensure that the pending data are furnished to PRDC positively by Non-compliance in this regard would be discussed in the meeting. 8. Other Protection Issues, if any, with the permission of the Chair 9. Sending Agenda items for the PCSC meetings As per the Guidelines of CEA/MOP, it has been decided to conduct the PCSC meetings on monthly basis. It is requested that Agenda Items for the PCSC meetings, if any, may please be sent latest by 5 th working day of the month to SRPC Secretariat to compile and circulate the same so as to have fruitful discussions in the PCSC meetings. Agenda for the 75 th Meeting of PCSC scheduled to be held on 28 th June, 2018 Page 4

8 10. Date of next PCSC meeting It is informed that the 76 th meeting of PCSC will be held on 26 th July, 2018 (Thursday) from 10:30 onwards in the Conference Hall of SRPC Secretariat, Bengaluru. Further, in view of the time-bound nature of PMS project, it is also intimated that a review-meeting on submission of pending PMS Data to PRDC would be conducted with concerned Nodal Officers of the Utilities on 27 th July, 2018 (Friday) from 10:30 onwards in the Conference Hall of SRPC Secretariat, Bengaluru. ***** Agenda for the 75 th Meeting of PCSC scheduled to be held on 28 th June, 2018 Page 5

9 Grid Occurrences - 75 For all tripping events involving failure of substation equipment, Constituents are requested to kindly furnish the SLD or equivalent pictorial representation showing (i) Location of the fault, and (ii) Bus-bar arrangement/ Configuration of feeders and other connected equipment with proper CB positions (OPEN/ CLOSE) at the time of occurrence of the fault. I. Details of Grid Disturbances: Sl. No. Details of Event Date &Time Reason Remarks Category Complete outage of 220kv Kadra Station Complete outage of 400kV Kalikiri and 400kV RYTPP station Complete outage of 400kV Kalikiri and 400kV RYTPP station Complete outage of 220kV Villianur station Complete outage of 400 kv Uravakonda SS and 400kV Jammalamadugu SS of APTRANSCO 21:54 on :08 on :24 on :40 on :37 on Triggering incident was snapping of tower earth guard conductor above 220kV bus. Bus bar protection operated resulting in complete outage of 220kV Kadra station. 220kV Kadra station was on single bus operation. Triggering incident was R-N fault in 400kV RTPP- Kalikiri Ckt-1. Auto reclose(ar) was successful at Kalikiri end but didn t operate at RTPP end. This led to tripping of running unit at RYTPP due to tripping of evacuating line and complete outage of RYTPP. At the same time 400kV Chittoor-Kalikiri line 1&2 got tripped from Chittoor end on operation of Z3 (mal-operation) resulting in loss of supply to Kalikiri station. Triggering incident was R-N fault in 400kV RTPP- Kalikiri Ckt-1. Autoreclose(AR) was unsuccessful at Kalikiri end. This led to tripping of running unit at RYTPP due to tripping of evacuating line and complete outage of RYTPP. At the same time 400kV Chittoor-Kalikiri line 1&2 got tripped from Chittoor end on operation of Z3 (mal-operation) resulting in loss of supply to Kalikiri station. Triggering incident was failure of R- Phase CT of 230kV/ of ICT -2 at 230kV Villianur station. 230 kv Neyveli - Villanur and 230kV Pondy - Villianur lines tripped from Neyvelli end and Pondycherry end respectively.this led to loss of supply to 230kV Villianur station. 400kV Jammalamadugu UV Konda line- 1, Narnoor-2 and 400kV UV Konda Mahabubnagar line-1 got tripped on overvoltage protection. This led to the loss of supply to 400kV UV Konda and 400kV Jammalamadugu stations. Subsequently due to loss of 400kV evacuating lines, wind generators at Gen Loss: 318 MW Gen Loss: 293 MW Load Loss: 130 MW Gen Loss: 275 MW GD-1 GD-1 GD-1 GD-1 GD-1 Grid Occurrences to be discussed in the 75 th Meeting of PCSC scheduled to be held on 28 th June, /5

10 6 7 Complete outage of 230 kv Villianur SS of PED Complete outage of 400 kv Uravakonda SS of APTRANSCO 11:23 on :34 on kV level got tripped, resulting in the loss of supply to 400/220kV UV Konda and 400/ 220 kv Jammalamadugu stations Triggerring incident was the failure of R-ph breaker of Kalappet Villianur line got failed at Villianur end. Fault was cleared by tripping of the upstream feeders. 230kV NLC st-2 Villianur tripped at NLC end and 230kV Pondy Villianur line tripped at Pondy end on zone 3 distance operation, resulting in the loss of supply to 230kV Villinanur station. 400kV UV Konda- Jammalmadugu line- 1 and 400kV UV Konda Mahabubnagar line-1 tripped at due to over voltage protection operation. Since 400kV UV Konda Jammalmadugu line-2, Mahabubnagar 2 were in open condition, after the tripping of lines, 400/220kV ICT #1,2,3 and 4 at 400kV UV Konda were hand tripped due to loss of evacuating lines. Load Loss: 120 MW Gen Loss: 500 MW GD-1 GD-1 II. Details of Grid Incidents: Sl. No. Details of Event Date &Time Reason Category 1 2 Tripping of 400 kv Vijayawada Vemagiri line-1 Tripping of 400kV Hinduja-K.V.Kota line-2 01-May-2018 at 16:09 01-May-2018 at 10:12 Line tripped on operation of Over-voltage at Vijayawada and direct trip receive at Vemagiri. The voltages recorded in Vijayawada end DR kv, 249 kv, 243 kv. The Y-phase voltage was observed to be higher when compared to R & B phases. Line-2 tripped on direct trip receive at K.V.Kota end. At the same time there was an un-successful auto-reclose attempt in line due to persistent fault in B-phase. GI-2 GI-2 3 Tripping of 400/220kV ICT-4 at Uravakonda 03-May-2018 at 17:57 ICT-4 at Uravakonda tripped without any relay indication GI-2 4 Tripping of HVDC Talcher-Kolar Pole May-2018 at 19:34 Line fault occurred in HVDC Pole-1. Wave front and undervoltage protection end operated to Kolar end, initiating DC line fault recovery sequence. After three attempts pole-1 got tripped. Pole-2 went to ground return mode after the tripping of pole-1 Grid Occurrences to be discussed in the 75 th Meeting of PCSC scheduled to be held on 28 th June, /5

11 5 6 7 Tripping of 400 kv Kolar Tiruvelam line Multiple tripping at 400 kv Raichur-PG SS Tripping of 400 kv Nelamangala-Mysore line-1 03-May-2018 at 23:40 03-May-2018 at 18:03 04-May-2018 at 01:28 Line tripped on operation of over-voltage stg-1 protection at Kolar and direct trip was received at Tiruvelam. It Y phase voltage is 5kV higher when compared to to R & B phase at Kolar. 400 kv RTPS Raichur PG line-2 tripped due failure of LA in B-phase. 400 kv RTPS Raichur PG line-1 & 400 kv Raichur(PG) - Gooty line-1 tripped on operation of overvoltage. Suspected mal-operation of over Voltage Stage 2 at Nelamangala end and direct trip sent to Mysore end. At same time, Y-phase to earth fault had occurred in 400 kv Nelamangala-Hassan Line. GI-2 GI-2 GI-2 8 Tripping of 400/220 kv ICT-3 at Trichur 09-May-2018 at 22:26 ICT tripped on operation of REF protection. Along with ICT-3, 220KV Lower periyar- Madakathara line-1&2 also got tripped. GI Tripping of 400 kv BTPS-JSWEL Tripping of HVDC Talcher-Kolar Pole-1 11-May :32:00 16-May-2018 at 15:35 Over voltage stg-1 operated at BTPS and DT received at JSWEL. Voltage difference was observed between R, Y &B phases (R- 253kV, Y-233kV & B-234kV). Line fault occurred in HVDC Talcher-Kolar. Pole-1 got tripped at Talcher end and ESOF was sent to Kolar end. Pole-2 went to ground return mode after the tripping of pole-1 GI-2 11 Tripping of 400/230 kv ICT-2 at S.V.Chatram 20-May-2018 at 12:30 ICT-2, R-Ph. Unit Bucholz operated due to suspected oil surge during SLG faults in 230 kv NOKIA and 230KV SIPCOT lines. GI Tripping of HVDC TALCHER - KOLAR LINE 2 Multiple trippings at 400/ 220 kv Guttur sub-station Multiple trippings at 400/ 220 kv Madakathara substation of KSEB 26-May-2018 at 17: at 00: at 16:26 Talcher Kolar Pole -2 tripped on external protection trip operation at Talcher end. ESOF signal was received at Kolar end. Pole- 1 went to metallic return mode Triggering incident was failure of rigid bus of isolator of 220kV Guttur -Haveri line-1 at 220kV Guttur end. This resulted in bus fault and 220kV Bus bar protection operated resulting in the tripping of all elements connected to 220kV Guttur Bus kV Guttur was on single bus operation. 400/220 kv ICT-3 tripped on REF protection, 220kV Madakathara-Areakode, 220kV Madakathara-Shoranur tripped due to earthwire snapping. GI-1 GI-2 15 Tripping of 400kV JSWEL -BPS-2 29-May-2018 at 17:41 Line tripped at JSW end only on maloperation of SOTF protection in Main#2 distance protection relay. Line was in service from BPS end. GI-2 Grid Occurrences to be discussed in the 75 th Meeting of PCSC scheduled to be held on 28 th June, /5

12 16 Tripping of 400/220 kv ICT-1 at BTPS 29-May-2018 at 18:15 ICT got tripped on operation of backup over current protection (high set) during R-N fault in 220kV BTPS-Lingapur line. GI-2 17 Tripping of 400 kv Kurnool-Srisailam line 31-May-2018 at 01:41 Line tripped on operation of over-voltage stg-1 protection at Srisailam and direct trip was received at Narnoor. Voltage recorder in Srisailam end DR (R:254 kv, Y:247 kv, B:234 kv) GI Tripping of 400 kv Satenapalli-Srisailam line-2 Tripping of HVDC Talchce Kolar Pole-2 31-May-2018 at 16:41 31-May-2018 at 18:19 Line tripped at Srisailma end only and was holding from Satenapally end.. HVDC Talcher-Kolar Pole-2 tripped on fault. DC line fault recovery sequence was not successful. Pole-1 went to ground return mode after the tripping of pole-2 GI-2 III. Details of Trippings due to Failure or Non-operation of Auto-Reclose: Sl. No. Element Date & Time Reason 1 Tripping of 400kV VTPS- Satenapalli line-1 01-May-2018 at 15:40 Line tripped on R-phase to earth fault. Auto-reclose was successful at Satenapalli end and breakers got tripped at VTPS (R,Y, B pole trip) Tripping of 765kV Srikakulam-Angul line-2 Tripping of 400 kv Alamathy-Vallur line-2 Tripping of 400 kv Neyveli TS 2 (Exp.) Pugalur line Tripping 765kV Srikakulam Vemagiri line -1 Tripping of 400 kv Warangal- Boopalapalli line-2 Tripping of 765 KV Raichur - Kurnool line- 1 Tripping of 220kV Sedam-Tandur line-1 01-May-2018 at 06:36 01-May-2018 at 19:58 03-May-2018 at 05:49 03-May-2018 at 05:51 03-May :56:00 03-May-2018 at 17:17 06-May-2018 at 14:24 B-phase to earth fault occurred in line. Auto-reclose was successful at Srikakulam and breakers got tripped at Angul. Line was holding from Srikakulam end after auto-reclose. Line tripped on R-phase to earth fault. Auto-reclose did not operate at Alamathy end as Main-2 distance protection relay issued 3-phase trip. Direct trip was received at Vallur end. R-phase to earth fault occurred in line. Auto-reclose did not operate at Pugalur as direct trip was received from NLC end. At NLC end over-voltage stg-2 operation. Y-phase to earth fault occurred in line. Autoreclose was successful at Vemagiri end and breakers got tripped at Srikakulam end without A/r attempt. B-phase to earth fault occurred in line. Auto-reclose was successful at warangal. At Bhoopalapalli end A/R did not operate due to direct trip receive (observed in DR event log) B-phase to earth fault occurred in line. Auto-reclose was successful at Kurnool and A/R did not operate at Raichur. R-phase to earth fault occurred in line. Zone-1 indications at Tandur end. A/R not operated at Tandur end as Main-1 relay is unhealthy/ damaged in which Grid Occurrences to be discussed in the 75 th Meeting of PCSC scheduled to be held on 28 th June, /5

13 A/R function is enabled Tripping of 400 kv Kaiga - Guttur line-1 Tripping of 400 kv Narasapur Shankarapally line Tripping of 220 kv Regulapadu-Alipura line Tripping of 400 kv Gajuwaka-Vemagiri(PG) Tripping of 400 KV Kudgi(PG) -Kudgi(NTPC) line-4 Tripping of 400 kv Nelamangala-Hoody line-1 Tripping of 400 KV Uravakonda- Jamalamadugu line - 1 Tripping of 400kV Pavagada-Gooty line-2 17 Tripping of 400KV Hinduja-K.V.Kota line-1 18 Tripping of 220 kv Regulapadu-Alipura line Tripping of 400 KV Thiruvelam-Palavadi line-2 Tripping of 400 kv Kaiga-Guttur line-2 Tripping of 400 kv VTPS IV - Satenapalli line kv GAJWEL - SHANKARPALLY line-1 08-May-2018 at 17:54 09-May-2018 at 16:15 10-May-2018 at 17:55 11-May-2018 at 22:43 11-May-2018 at 16:08 18-May-2018 at 16:28 19-May-2018 at 18:57 21-May-2018 at 21:48 21-May-2018 at 10:28 21-May-2018 at 07:52 25-May-2018 at 18:35 27-May-2018 at 18:39 31-May-2018 at 16:41 31-May-2018 at 02:15 B-phase to earth fault occurred in line. Auto-reclose not operated at Kaiga end due to DT receipt. B-phase to earth fault occurred in line. Auto-reclose was successful at Shankarapalli and breakers tripped at Narsapur end R-phase to earth fault occurred in line. Auto-reclose was not attempted at Alipura end. At Regulapadu end, relay sensed the fault as Y-N fault. Y-phase to earth fault occurred in line. Over voltage stg-2 got operated at Vemagiri (PG) end during autoreclose dead time resulting in a 3 phase trip and direct trip sent to Gazuwaka. line tripped on Y-phase to earth fault. Auto-reclose did not operate at Kudgi (PG) due to direct trip receive Y-phase to earth fault occurred in line due to jumper snapping. Auto-reclose was not attempted as there was DT receive at Nelamangala from Hoody end Y-phase to earth fault occurred in line. Auto-reclose was not attempted at both ends. B-phase to earth fault occurred in line. Auto-reclose was successful at Pavagada and breakers at Gooty end got tripped. B-phase to earth fault occurred in line. Auto-reclose attempt was not-successful at HNPCL due to persistent fault. At K.V.Kota end a/r was not attempted Y-phase to earth fault occurred in line. Auto-reclose was not successful at regulapadu as fault was persistent. At Alipura end line tripped in zone-2. Y-N fault was sensed at Alipura and as B-N fault at Regulapadu. R-phase to earth fault occurred in line. Autoreclose was successful at Thiruvelam and did not operate at Palavadi. R-phase to earth fault occurred in line. Auto-reclose was successful at Guttur end. A/r not operated at Kaiga Line tripped on R-phase to earth fault. Auto-reclose did not operate at VTPS R-phase to earth fault occurred in line. Auto-reclose was successful at Shankarapally end. In Gajwel end A/R operated and again tripped on operation of Group A/ B relay. Grid Occurrences to be discussed in the 75 th Meeting of PCSC scheduled to be held on 28 th June, /5

14 IV. Details of Trippings due to PLCC mal-operation: Sl. No. Element Date & Time Reason Tripping of 400 kv Khammam Mamidapally- 2 Tripping of 400 kv Ramagundam-Gajwel line Tripping of 400 KV Kudgi(PG) -Kudgi(NTPC) line-4. Tripping of 400 KV KUDGI(PG) - KUDGI(NTPC) line KV KUDGI(PG) - KUDGI(NTPC) 4 Tripping of 400 kv Vemagiri-Simhadiri line- 2 Tripping of 400 kv NEYVELI TS 2- SALEM line-2 03-May :19 08-May :07 12-May-2018 at 21:33 22:37, 22:24 &17:12 on 13-May May-2018 at 16:03 17-May :15:00 22-May-2018 at 09:37 Line tripped on direct trip receive at both ends. Line tripped at Gajwel end & was holding from Ramagundam end. When N'Sagar line-2 tie Breaker was being hand tripped, Direct trip incremented for Gajwel Line in one channel which resulted in tripping of breakers at Gajwel. Line tripped at Kudgi(NTPC) end only and was in service from Kudgi(PG). Suspected PLCC maloperation. line tripped at Kudgi(PG) end on direct trip receive at 1712 and 22:24 from Kudgi(NTPC). At 22:37 line tripped at Kudgi(NTPC) end only. The tripping occurred due to suspected PLCC maloperation. Line tripped on DT receive from KUDGI, NTPC end. Suspected PLCC mal-operation. Vemagiri end breaker tripped on DT receive from Simahadri due to suspected mal-operation of Digital Protection coupler. Line was in charged condition from Simhadri end. line tripped at NLC end only on direct trip receive and was in in service from Salem. Suspected PLCC mal-operation. ***** Grid Occurrences to be discussed in the 75 th Meeting of PCSC scheduled to be held on 28 th June, /5

15 Status of Implementation of PCSC Recommendations as on (up to 74th Meeting) Meeting No / Index Details of Event Date & Time Reason PCSC Recommendations Utility responsible for Implementation Status of Implementation of PCSC Recommendations Remarks Multi-Utilities 34/I/6 400/220 kv ICT-1 & 2 at Munirabad As reported directional over current relay of ICT s operated due to snapping of line jumper in 220kV Lingapur line. 1. Bus bar protection shall be provided by asset owner ( i.e KPTCL). 2. Settings for main distance protection & Overcurrent protection shall be examined and reviewed. 3. Time synchronization of the Substation shall be ensured. KPTCL/ PGCIL (SR-I) KPTCL Mail dated : 1. KPTCL has taken action to provide bus bar protection to 220kV buses Over current relay Settings of ICTs to be reviewed by PGCIL KPTCL Mail dated : 1. Initial Tendering stage (with KPTCL) KPTCL Mail dated on : 1. Detailed estimate prepared for taking up the work. CEE, Transmission Zone, Gulbarga will take up necessary procurement and further execution with PGCIL (SR-I) PGCIL (SR-I) Mail dated : 2. Relay settings of all the stations in SRTS-1 were derived as per Ramakrishna Commettee recomendations and implemented" --- Completed. KPTCL Mail dated : 1) & 3). DPR is approved. Tender is to be called by CEE,TZ Kalaburgi 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, PGCIL (SR-I) informed that time-synchronization of 220 kv side is in place. --- Completed. 47/I/2 Complete outage of As per FIR submitted, CT damage observed in Chitoor- 1. APGENCO to furnish to PCSC forum (i) A3-size Single Line APGENCO/ APGENCO letter dated : Krishnapatnam TPS at 18:20 Diagram of SDSTPS, and (ii) the sequence of events with time PGCIL (SR-I) stamp showing the protection that opened Tie-CB (405) at SDSTPS. Main bay (404). Main breakers connected to bus-1 (401, 404, 407, 410) got tripped on operation of bus bar protection. Unit-1 tripped on operation of MFT. Unit-2 was not in service 2. APGENCO to review STUB/TEED protection in all dias at SDSTPS and ensure that they are configured for instantaneous operation. 3. APGENCO to properly configure the STATE of the tripping events so that they get recorded appropriately like TRIP/ OPERATED in their corresponding Event Loggers. 4. APGENCO to ensure time sync of all DR s and EL s at SDSTPS. 5. PGCIL (SR-I) to provide line differential protection for 400 kv NPS Nellore-PG lines 1 & 2. 1.SOE and SLD are attached. The DR of 405 CB is not generated during the incident. Now the problem is identified and rectified Completed 2.All the 3 lines i.e CHTR-2, MNBL-I & II tripped in zone protection. The fault was in Blind zone i.e P2 side of CT, where it was covered under Bus fault by the time fault moved on to P1 side when the fault comes under STUB/TEED zone after 330msec all the feeders expect CHTR-1 tripped in Zone-II and total fault persisted for 500msec before the 405 TIE CB opens and clear the fault. As a remedial the STUB protection operation also checked and found OK Completed 3.The Time Sync was missed on the day and found there was problem with LAN Timer same was rectified. Now found OK Completed 4.Now the DR Time scale changed to 1 sec for Pre fault and 3 sec for Post fault and STATE of events are corrected wherever found wrong/or misguiding during analysis completed. PGCIL-SR1 RVMD : 5. Procurement of differential protection for 400kV NPS-NLR D/C and 400kV RCR-RTPS-D/C is under tendering. PGCIL-SR1 RVMD : 5. The proposal for procurement of Line differential Protections for 400kV Raichur - RTPS-1 & 2 and 400kV Nellore - NPS - 1 & 2 lines has been approved and tender is under technical evaluation [with PGCIL (SR-I)] Page 1 of 44

16 evaluation PGCIL (SR-I) Mail dated : PGCIL: On LDP relays commissioned in place of Main-1 distance relay in 400kV NPS- Nellore line-2 & In line-1 installation of LDP relay is planned in Dec-2017/Jan PGCIL (SR-I) informed that LDP commissioning on both lines would be completed by February, In this regard, PCSC made it clear that the recommendation pertains to providing LDP as both Main-I & Main-II on both the lines, and asked PGCIL (SR-I) to ensure & comply with the same. 47/II/7 Tripping of 220 kv Kadra-Karwar at 220kV Kadra-Karwar lines-1&2 tripped 1. KPTCL/ KPCL to see the possibility of implementing Weak KPTCL/ KPCL/ KPTCL Mail recieved on : lines - 1&2 and 220kV Kaiga- 11:44 Infeed logic with Echo feature enabled by Under NPCIL (KGS) Kadra line Voltage (27) element on Kadra-Karwar lines 1 &2, and implement the same if feasible. on earth fault in B-phase in zone-2. Kaiga-Kadra line tripped at Kaiga end only on operation of directional eath fault protection. 2. NPCIL to time-coordinate Kaiga s DEFR settings with (i) Zone-2 settings at Kaiga, and (ii) primary protections of the lines emanating from Kadra and Kodasalli. 1. Availability of week end infeed with eco feature to be confirmed by SEE,RTC,Hubli ---. NPCIL (KGA) Mail recieved on : 2. The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga Kodasally lines were disabled. IDMT DEFR is retained. The 200 ms Definite time back up o/c element in both Kaiga Kadra and Kaiga Kodasally lines were disabled. IDMT is retained. --- Completed. [with KPTCL] 3. KPCL to ensure time-sync of EL s, and healthiness of the Fault Locators at Kadra. Status received vide KPCL mail dated & : 1. Since PT blasted (B phase) at Karwar end, resistive over reach occurred. hence Backup protecion operated at Kadra end (zone-2 not sensed) Completed 3.Newly commissioned micom P444 relay time synchronised with GPS Completed. KPTCL Mail dated : 1. Week end infeed logic will be enabled in the new numerical relays supplied to Karwar under R&U during retrofitting works KPTCL informed that since the line is a double circuit, there may not be need for implementing Weak Infeed logic with Echo feature at Karwar end. However, the same would be looked into w.r.t. the newly commissioned NR's at Karwar, and final action taken would be informed by March, /I/2 Complete outage of TPCIL power station at 06:02 Running units at Thermal Powertech power Station tripped due to tripping of 400kV Nellore pooling station (NPS)-TPCIL line and 400kV Nellore pooling station (NPS)- NCC line 1.PGCIL (SR-I) to furnish Action Taken Report on the findings of OEM on relay mal-operation at NPS end on 400 kv NPS NCC line to PCSC forum. 2. PGCIL (SR-I) to appropriately configure Station Event Logger at NPS to record events at msec interval. 3. PGCIL (SR-I) to carry out PLCC end-to-end testing in coordination with TPCIL for 400 kv NPS TPCIL line. 4.PGCIL (SR-I), MEPL, SEL, TPCIL & NCC to take steps to provide line differential protection at their respective ends on all 400 kv lines (except Gooty line) emanating from Nellore Pooling Station, and furnish an action plan to implement the same. PGCIL (SR-I), MEPL, SEL, TPCIL, NCC PGCIL (SR-I) mail received on : 1. The firmware of REL670 is being upgraded Completed. 2. The recording of events in msec interval is being taken up with OEM. Henceforth, for analysis purpose, we will provide larm list which has msec time stamp Completed. 3. End to end testing of PLCC code transmision and tuning of channels carried out Completed. 4. Procurement of differential protection for 400kV NPS-NLR D/C and 400kV RCR-RTPS-D/C is under tendering. The legends modified in Event/alarm list. Provision of diff. relay for all short lines emanating from NPS is being taken up with our corporate PGCIL(SR-I) RVMD : 4. The proposal for procurement of Line differential Protections for 400kV Raichur - RTPS-1 & 2 and 400kV Nellore - NPS - 1 & 2 lines has been approved and tender is under technical evaluation --- Page 2 of 44

17 PGCIL (SR-I) Mail dated : 4. LDP relays procurement is under process. Procurement will be completed by Feb TPCIL has to give written confirmation for LDP relay procurement. For want of written confirmation from TPCIL, PGCIL approving authority has withheld the LDP proposal. 4. PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete procurement of LDP relays. To this, PCSC forum asked TPCIL to submit written confirmation to PGCIL (SR-I) by 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, APTRANSCO informed that they would be able to implement LDP from their & APGENCO side by April, 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. Page 3 of 44

18 51/II/6 Tripping of 400kV Sattenapalli- Vijayawada line at 3:01 Line tripped due to operation of over voltage protection at Vijayawada end and Direct Trip was received at Sattenapalli end 1. PGCIL (SR-I), in co-ordination with APTRANSCO, to address the problem with CB at the earliest opportune time. 2. APTRANSCO to take steps to replace the faulty Event Logger at Vijayawada (Nunna) SS. PGCIL (SR-I)/ APTRANSCO PGCIL mail received on : Being pursued with APTRANSCO APTRANSCO mail dated on : AS maintenance being carrired out by PGCIL(SR-1), the required relay replacement (wiring/programming) may also be carried out by PGCIL(SR-1). PGCIL RVMD : 1. The CB problem has been attended by POWERGRID by using OEM M/s BHEL services & POWERGRID's O&M spares Completed. 2. Being pursued with APTRANSCO to replace the faulty Event Logger at Vijayawada (Nunna) SS APTRANSCO mail dated on & & : As maintenance being carrired out by PGCIL(SR-1), the required relay replacement (wiring/programming) may also be carried out by PGCIL(SR-1). APTRANSCO mail dated : May be coordinated with PGCIL APTRANSCO mail dated : PGCIL may be requested to take necessary action [with PGCIL (SR-I)] APTRANSCO mail dated : 2. EL procured and drawn. Configuration to be done by Alstorm company engineer. Will be configured in four weeks. --- PGCIL (SR-I) Mail dated : 2. APTRANSCO is to replace the faulty/outdated relays & POWERGRID has to maintain the relays after retrofitting. 2. APTRANSCO informed that the recommended works would be completed in one-month period. APTRANSCO Mail dated & As per the requirement of PGCIL.Event logger(bcu) with data base is configured and handed over to PGCIL/Nunna on 27 th dec 17.PGCIL is requested to take action for taking event logger (BCU) into service. 56/I/2 Complete outage of 220kV Sedam Substation of KPTCL at 15:27 220kV Sedam-Humnabad-2 tripped at Sedam on Distance protection, Zone-2. Sedam-RTPS-1 &2 lines tripped at RTPS end only. 220kV Tandoor inter-state line was hand tripped due to incoming supply failure KPTCL and TSTRANSCO to take steps to provide A/R feature on 220 kv Sedam Tandur inter-state line at their respective ends at the earliest. KPTCL/ TSTRANSCO KPTCL Mail dated : Carrier protection is to be restored. B/U OC and EF relay is to be replaced by M-II distance relay. Required materials like wave trap, M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd. --- [with KPTCL] TSTRANSCO informed that they have kept A/R in service from Tandur end. KPTCL informed that the works relating to put A/R in service are going on at their Sedam SS, and assured that it would be put into service by February, Page 4 of 44

19 56/II/13 Tripping at 220 kv Gooty Substation of APTRANSCO at 16:04 LBB protection got operated for 400/220kV ICT-2 breaker which had resulted in tripping of 220kV Bus-2 at 220kV Gooty Substation 1.APTRANSCO to check the healthiness of the connecting cable between Gooty (PGCIL) and Gooty (APTRANSCO), and replace it, if required. 2.APTRANSCO to ensure that the distributed architecture employed in implementing busbar protection at their Gooty 220 kv SS does not introduce any unwarranted delays in transmitting the triggering signals to the Central Unit. APTRANSCO/ PGCIL (SR-I) APTRANSCO mail dated on : [ with To avoid the unwanted malopeartions due to the external LBB trip initiation from PGCIL, Vide PGCIL (SR-I) ] letter Dt: , APTRANSCO has requsted the PGCIL to arrange the Master trip relay and breaker contacts of ICT-1 &2 LV side to enable the internal LBB feature in the Busbar protection scheme at 220kV Gooty Switching station. Waiting for the PGCIL response. APTRANSCO mail dated on : To avoid the unwanted maloperations due to the external LBB trip initiation from PGCIL, vide letter Dt: , ARTRANSCO has requested the PGCIL to arrange the Master trip relay and breaker contacts of ICT-1&2 LV side to enable the internal LBB feature in the Busbar protection scheme at 220kV Gooty Switching station. Waiting for the PGCIL response. APTRANSCO mail dated on : Waiting for the PGCIL response. APTRANSCO mail dated & SRPC is requested to coordinate with PGCIL in takind necessary action. APTRANSCO mail dated & PGCIL may be requested to take necessary action APTRANSCO maild ated : 1. Cable healthiness checked and found ok. But it is proposed to replace the cable with armored cable. --Completed 2. After replacing the cable contactors will be removed so as to avoid unwarrented delays in transmitting trigging signal to the central unit. --- APTRANSCO informed that replacement of the existing cable with armoured cable and subsequent removal of cable contactors would be completed by In this regard, PGCIL (SR-I) also assured that they would render all required help from their side to complete the stated works in time. APTRANSCO Mail Dated : New armoured cable is laid from 220 kv Gooty (AP) to 400/220 kv Gooty (PGCIL) for replacing the existing cable connected to ICT-2.PGCIL is requested to provide spare contacts from trip relays of 315 mva LV-1 and LV-2 for providing internal CB failure in busbar protection scheme. APTRANSCO Mail Dated & : As requested by PGCIL the busbar drawings Were submitted for providing spare contacts from trip relays of 315 mva LV-1 and LV-2 for providing LBB in busbar protection scheme. 56/III/4 Tripping of 220 kv Sedam-Tandur line at 21:52 Line tripped on B-phase to earth fault. Auto-reclose is not enabled for line. KPTCL and TSTRANSCO to fast-track providing A/R on 220 kv Sedam Tandur line, and furnish an action plan of providing the same by next PCSC meeting (PCSC-57). KPTCL/ TSTRANSCO KPTCL Mail dated : Carrier protection is to be restored. B/U OC and EF relay is to be replaced by M-II distance relay. Required materials like wave trap, M-II distance relay are already supplied. The work will be taken up on top priority through GE Ltd. (With KPTCL) TSTRANSCO informed that they have kept A/R in service from Tandur end. KPTCL informed that the works relating to put A/R in service are gonig on at their Sedam SS, and assured that it would be put into service by February, TSTRANSCO MAIL DATED : As discussed in the review meeting on , A/R is kept in service from Tandur(TSTRANSCO) end.--- TSTRANSCO MAIL DATED : Issue is not pending from TSTRANSCO side. Page 5 of 44

20 57/I/1 Complete outage of 220 kv Karwar Substation of KPTCL at 11:36 Triggering incident was failure of R phase PT in Bus-1 at 220kV Karwar substation. 220kV Kaiga-Kodasalli tripped during the incident. Also bus shut down occurred at Kadra and Kodasally stations. 1.NPCIL (KAPS) to disable DefiniteTime O/C relay, and put in its place by IDMT O/C relay for backup protection on both 220 kv Kaiga Kadra line and 220 kv Kaiga Kodasalli line at Kaiga end. 2.KPTCL to put bus bar protection in service at their 220 kv Karwar SS at the earliest. KPTCL/ KPCL/ NPCIL (KGS) NPCIL(KGS) mail dated on & : 1.The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga Kodasally lines were disabled. IDMT DEFR is retained. --- Completed [with KPCL & KPTCL] 3.KPCL/ KPTCL to implement Weak In-feed Logic with Echo feature enabled by Under Voltage (27) element on Kadra Karwar lines 1 & 2. 4.KPTCL to furnish equipment failure report of the current incident to PSE&TD Division of CEA with a copy marked to SRPC. KPTCL Mail dated : 2) Bus-bar protection panel is supplied under R&U. Replacement work will be taken up after priority Sub stations ] Weak end Infeed logic available in new relays supplied; Will be enabled During R&U works ] Equipement failure reports are being sent to CEA regularly. --- Completed 2. KPTCL informed that the works relating to providing BBP are targeted to be completed by March, KPTCL informed that since the line is a double circuit, there may not be need for implementing Weak Infeed logic with Echo feature at Karwar end. However, the same would be looked into w.r.t. the newly commissioned NR's at Karwar, and final action taken would be informed by March, /II/9 Tripping of 400 kv Nellore (PG) - NPS line-1, 400 kv Krishnapatnam-Nellore (AP) lines -1&2 and 400kV NPS - MEPL line at 19:05 Triggering incident was snapping of Y phase conductor in 400kV Nellore (PG) - NPS line-1. Distance relay at Krishnapatnam end over-reached in Zone-1, and resulted in tripping of 400kV Krishnapatnam Nellore (AP) lines - 1&2 from Krishnapatnam end. Distance relay at MEPL over-reached and resulted in tripping of MEPL-NPS line from MEPL end. PGCIL (SR-I), TPCIL, MEPL, SEL, SGPL, APTRANSCO, APGENCO and SDSTPS to implement line differential protection on all 400 kv transmission lines (of length less than 50 km) emanating from Nellore PS, Nellore (PG) SS, and Nellore (AP) SS. [It may be noted here that the cut-off length of 50 km has been specified with a view to exclude only long transmission lines]. APGENCO/ PGCIL(SR-I)/ TPCIL/MEPL/SEL/ SGPL/ APTRANSCO APTRANSCO mail dated on : Issue was addressed to the concerned for necessary action. APTRANSCO mail dated on : Meeting was conducted and the relays procurement for all the loctions is under progress. APTRANSCO mail dated on & : Relays procurement for all the locations is under progress. APTRANSCO Mail dated : Technical bids opened. PQ evaluation under progress. Price bids expected to open in next week. PGCIL (SR-I) Mail dated : LDP relays procurement is under process. Procurement will be completed by Feb TPCIL has to give written confirmation for LDP relay procurement. For want of written confirmation from TPCIL, PGCIL approving authority has withheld the LDP proposal. PGCIL (SR-I) informed that they are waiting for written confirmation from TPCIL to complete procurement of LDP relays. To this, PCSC forum asked TPCIL to submit written confirmation to PGCIL (SR-I) by 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, APTRANSCO informed that they would be able to implement LDP from their & APGENCO side by April, 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. APTRANSCO MAIL DATED Technical & financial bids are opened. Tenders will be awarded shortly. APTRANSCO Mail Dated : ABB make LDP relays inspection is completed. SNEIDER make LDP relays inspection yet to be completed. Delivery of relays expected in the 1st weak of May APTRANSCO Mail Dated : SNEIDER make LDP relays inspection yet to be completed.delivery of relays expected in the month of june Page 6 of 44

21 63/II/9 Tripping of 400 kv YTPS-BTPS line and 400 kv BTPS-JSWEL line at 19:11 R-phase to earth had occurred in 400kV BTPS-JSWEL line and protection issued a 3 phase trip 1. JSWEL to follow file naming terminology provided by SRPC for various tripping files uploaded in SRLDC s TMS portal. 2.JSWEL to furnish reasons for AR-BLOCK observed during the instant tripping and remedial action taken by them to keep A/R in service. 3. KPCL to configure DR & EL properly to record OVR Stage-I & Stage-II protections at their BTPS station. KPCL/ JSWEL Status received vide mail dated : 1. JSWEL will follow the file naming terminology provided by SRPC during future uploads Completed 2. Auto-reclosure is in service for JSW BTPS line. The reason for AR-Block was due to carrier fail signal which was after the fault clearance. As per the attached event list, the fault occurred at 7:11:21:550 PM & the AR block appeared around 7:11:21:586 PM, after the clearance of the fault at around 7:11:21:583 PM (3PH-TRIP) -----Completed with KPCL 3. KPCL informed that DR's & EL's had been configured for OVR (Stage-I & Stage-II) protections at their BTPS sttaion, and the exact date of completion of the same would be intimated soon. JSWEL Status received vide mail dated : 1. JSWEL will follow the file naming terminology provided by SRPC during future uploads. 2. Auto-reclosure is in service for JSW BTPS line. The reason for AR-Block was due to carrier fail signal which was after the fault clearance. As per the attached event list, the fault occurred at 7:11:21:550 PM & the AR block appeared around 7:11:21:586 PM, after the clearance of the fault at around 7:11:21:583 PM (3PH-TRIP) Page 7 of 44

22 64/I/1 Complete outage of North Chennai TPS STG at 21:02 Tripping of evacuating lines due to fault led to tripping of Units TANTRANSCO and PGCIL (SR-II) to take steps to complete insulator replacement works on the 400 kv lines owned by them in Chennai area within 3 months. TANTRANSCO/ PGCIL(SR-II) Status received vide TANTRANSCO mail dated & & & : 1. All the Porcelain insulators of 400kV NCTPS-II - Vallur feeders-1&2 were replaced with Polymer insulators by Completed 2. Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer insulators in a phased manner. --- [with TANTRANSCO] PGCIL (SR-II) Mail dated : Pertaining to POWERGRID all the porceleing insulators in the polluted streches has been completed. - Completed. 64/I/2 Complete outage of North Chennai TPS STG at 18:27 Tripping of evacuating lines due to fault led to tripping of Unit TANTRANSCO informed that a total of 597 insulators ahd alreeady been replaced, and the total replacement would take another 9-month period. In this regard, TANTRANSCO was asked to furnish detailed plan of action regarding replacement of insulators on all 400 kv lines owned by them in Chennai area. 64/I/3 Complete outage of North Chennai TPS STG at 21:09 Tripping of evacuating lines due to fault led to tripping of running Unit at NCTPS Stg-2 TANTRANSCO MAIL DATED : Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer insulators in a phased manner. Timeline: Sep Detailed plan of action will be submitted. TANTRANSCO MAIL DATED : Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer insulators in a phased manner. Timeline: Sep Detailed plan of action will be submitted. TANTRANSCO MAIL DATED : Existing Porcelain insulators of all other 400kV feeders are being replaced with Polymer insulators in a phased manner. Timeline: Sep Detailed plan of action will be submitted. Page 8 of 44

23 66/ II/ 8 Tripping of 400 kv Khammam KTPS lines 1 & at 18:32 Lines 1 & 2 tripped on B-phase to earth faults 1. TSGENCO to keep uniform A/R dead-time of 1 sec on the lines emanating from their KPTS station. 2. PGCIL (SR-I) to enable Trip-on-Reclose (TOR) functionality for Zone-2 faults for Khammam KTPS lines at Khammam end, if such a feature is available in the concerned relay, and to configure it for sending Direct Trip (DT) Command to KTPS end. 3. PGCIL (SR-I) to set right time-sync issues w.r.t. Khammam end Event Loggers on Khammam KTPS lines. 4. For 400 kv Khammam KTPS line-1, PGCIL (SR-I), in coordination with TSGENCO, shall carry out the following: (i) End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends. (ii) Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components shall be repaired/ replaced. TSGENCO/ PGCIL (SR-I) with TSGENCO PGCIL (SR-I) Mail dated : 2). TOR feature in MiCOM P444 relay enabled for 400kV KMM-KTPS lines at Khammam end. DT send on TOR trip is not as per protection philosopy. However if SRPC/SRLDC gives separate instructions exclusively for this line, the same shall be imoplemented after getting our CC approval ). At Khammam SS all DR & ELs are time synched. --- Completed. 4). --- TSGENCO Mail dated : 1). If the auto reclose function dead time kept same at both ends as 1 sec uniformly. In case of persistent fault, it leads to feed the fault from both ends and cause the generator breaker switching on to high fault current and chances of pole slip. To avoid this time differentiated A/R scheme to be implemented. In KTPS 400KV Line I & II at KTPS end dead time is 1.2sec and at KMM end it is 1sec. In our relay 7SA522 does not have the adaptive dead time function A/R. Hence, it is requested to send DT in case of on 3-phase trip and A/R unsuccessful at KMM end to avoid reclose attempt from KTPS end after dead time (1.2Sec) for persistent faults. [with PGCIL (SR-I)] We communicated to M/s Siemens to upgrade the firmware version regarding adaptive dead time. Hence, it is requested to review these settings to reduce the stress on Generating Station --- Completed 2. It was made clear to PGCIL (SR-I) that this is a specific case of those 400 kv lines where one one of the ends is a generating station, and the other end is grid-connected substation having TOR feature in line protection relays. The said recommendation of enabling TOR along with sending DT to the other end is basically to ensure safety of Generating Units at the other end. Accordingly, PGCIL (SR-I) was asked to take steps to ensure the same PGCIL (SR-I) informed that shutdown was availed by TSGENCO on , and all issues relating to PLCC including end-to-end testing were carried out. --- Completed Page 9 of 44