SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

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4 SOUTHERN REGIONAL POWER COMMITTEE BENGALURU Agenda for the 69 th Meeting of Protection Coordination Sub-Committee of SRPC to be held on 23 rd November, Introduction 2. Confirmation of Minutes of last PCSC meeting Confirmation of minutes of 69 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 October, 2017 given at Annexure-I would be discussed in the PCSC meeting. Constituents are requested to furnish the following information in respect of the above grid occurrences to have fruitful discussions. (a) Single line diagram of the station with switching devices, CT, PT and relay details. (b) Cause of the tripping & Remedial Action taken (c) Relay setting details Constituents are requested to bring/ furnish full particulars of the tripping events pertaining to their system. 3.2 In compliance of Regulations 5.2 (r) of IEGC, the Constituents are required to furnish the following information in respect of Grid Occurrences within 24 hrs of occurrence of the same to SRLDC/ SRPC: (a) First Information Report (FIR) (b) Event Logger (EL) output (c) Disturbance Recorder (DR) output (d) Trip event analysis report (with pre and post fault system conditions) Non-furnishing of tripping details (FIR/DR/EL/TR) for the period had been brought to Constituents notice vide letters (i) No. SRPC/ SE-III/ PCSC/ 2017/ dated , (ii) No. SRPC/ SE-III/ PCSC/ 2017/ 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 Status of implementation of pending PCSC recommendations (up to 67 th PCSC meeting) given at Annexure-II may please be sent latest by Remedial measures for "Transmission Elements under Forced Outage" Agenda for the 69 th Meeting of PCSC scheduled to be held on 23 rd November, 2017 Page 1

5 The Constituents are requested to furnish the remedial measures/ action taken by them for the tripping events as circulated vide our s. (Annexure-III) The tripping events are based on the daily reports at SRLDC website DailyReport.aspx under the menu: Reports->Daily-> "TL under Forced Outage") 4.3 Certificate for Healthiness of Batteries As per the MoP direction given in pursuant to recommendations of the Enquiry Committee (NEW grid disturbance on 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 month of October, 2017 is awaited from the following SR-Constituents: KPTCL, TANGEDCO, TANTRANSCO, PED, PGCIL (SR-I), NTPC-Kayamkulam & NTPL 5. Other Protection Issues, if any, with the permission of the Chair 6. 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. 7. Date of next PCSC meeting It is informed that the 70 th meeting of PCSC will be held on 21 st December, 2017 (Thursday) from 10:30 hrs onwards in the Conference Hall of SRPC Secretariat, Bengaluru. ***** Agenda for the 69 th Meeting of PCSC scheduled to be held on 23 rd November, 2017 Page 2

6 Grid Occurrences - 69 Annexure-I For all tripping events involving failure of substation equipment, Constituents are requested to kindly furnish the SLD or equivalent pictorial representation showing (i) Location of the fault, and (ii) Bus-bar arrangement/ Configuration of feeders and other connected equipment with proper CB positions (OPEN/ CLOSE) at the time of occurrence of the fault. I. Details of Grid Disturbances: Sl. No. Details of Event Date &Time Reason Remarks Category 1 2 Complete outage of 400kV TPCIL station Complete outage of 400kV TPCIL station at 19:33 hrs at 21:37 hrs 400kV TPCIL-Nellore PS line- 1 got tripped from TPCIL end during fault in 400kV Nellore-Nellore PS line-2. Running units at TPCIL got tripped due to loss of evacuating line. 400kV Nellore - Nellore PS line-1 and 400kV TPCIL - Nellore PS line-2 were under shutdown. 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. Generatio n loss : 1260 MW Generatio n loss : 1265 MW GD-1 GD-1 II. Details of Grid Incidents: Sl. No. Details of Event Date &Time Reason Category Multiple tripping at Tripping at 220kV Srisailam Right Bank power station Tripping of 220kV Sedam- Tandur line Tripping of 400kV Sattenapalli - Srisailam line at 14:39 hrs at 13:20 hrs at 16:00 hrs 220kV Srisailam RB Markapuram and 220kV tripped on operation of distance protection relay. Srisailam unit # 3, 4, 6 and 7 got tripped during the incident. 220kV Sedam - Humnabad line-1 tripped on distance protection due to conductor snaping. All the other lines connected to Bus-2 also tripped on operation of busbar protection. Line tripped on operation of over-voltage protection at Srisailam and direct trip was received at Sattenapalli. Considerable voltage difference was observed between GI-1 GI-1 GI-2 Grid Occurrences to be discussed in the 69 th Meeting of PCSC scheduled to be held on 23 th November, /4

7 Annexure-I R, Y & B phases at Srisailam end. 4 Tripping of 400kV JSW - Guttur line at 16:38 hrs and 23:53 hrs Line tripped on operation of over-voltage stage-1 protection at Guttur and direct trip was received at JSW. Considerable phase difference was observed between R, Y & B phases in DR of both ends. GI-2 5 Tripping of 765/400kV ICT-2 at Kurnool at 02:03 hrs ICT-2 got tripped due to mal-operation of Y-Ph ICT Bucholz-2 relay due to moisture ingress GI-2 6 Tripping of 400/220kV ICT-4 at Hyderabad at 21:35 hrs ICT-4 got tripped due to moisture ingress in Oil Surge Relay. GI-2 7 Tripping of 400kV Uravakonda Jamalamadugu line at 10:22 hrs Line tripped on overvoltage at Uravakonda end and direct trip received at Jamalamadugu end. DR & EL of uruvakonda end not furnished. GI Tripping of 220kV Kaiga- Kadra line-1 Tripping of 400kV Neyvelli TS-2 Pugalur and Neyvelli TS-2 (exp) Pugalur line Tripping of 400kV Hassan-UPCL line-1& at 22:22 hrs at 23:54 hrs at 16:11 hrs While desynchronising of Unit-2, B-phase pole of GCB did not open and pole descrepancy relay operated. Hence all 220KV lines CB hand tripped. Protection at NLCTS-2 & NLCTS-2 EXP has sensed as DLG fault and given a 3 phase trip. At Pugalur end protection has sensed fault as Y-N and B-N fault in 400kV Neyveli TS2-Pugalur line & 400kV Neyveli TS2 EXP-Pugalur line respectively. Breaker at Pugalur got tripped due to direct trip receive R-Y phase to earth fault in line-1 and R- phase to earth fault had occurred simultaneously in Line-1 & line-2 respectively. Line-1 got tripped due to DLG fault. In line-2 autoreclose was successful at Hassan and 3 phase trip at UPCL. GI-1 GI-2 GI-2 11 Tripping of 400/220kV ICT-1 at Neelamangala at 02:59 hrs ICT got tripped due to operation of over flux protection. GI-2 12 Tripping of 400/220kV ICT-2 at Asupaka at 20:34 hrs lct got tripped due to suspected maloperation of PRD. Fault was not observed from DR GI-2 13 Tripping of 400/220kV ICT-1&2 at Guttur at 17:15 hrs There was fault in 220kV Guttur Itagi (Jogihally) line. This resulted in operation of 220kV bus bar protection and 400/220kV ICT-1 & ICT-2 at Guttur tripped on 220kV side only. GI-1 Grid Occurrences to be discussed in the 69 th Meeting of PCSC scheduled to be held on 23 th November, /4

8 Annexure-I 14 Tripping of 400kV NPS - Nellore line at 12:06 hrs Line tripped on Y-phase to earth fault. Line auto-reclosed at NPS end. At Nellore, relay had sensed Y-B-E fault and issued 3 phase trip GI-2 15 Tripping of 400/220kv ICT-4 at Uravakonda at 17:04 hrs ICT-4 got tripped due to mal-operation of LV side pole discrepancy relay GI Tripping of 400kV Khammam-KTPS line-1 Tripping of 400/220kV ICT-1&2 at Guttur at 13:29 hrs at 16:03 hrs and 16:12 hrs B-phase to earth fault had occurred in line. At Khammam end direct trip receive was observed in DR which resulted in 3 phase trip. Wiring of new bus bar relay panel of 220kV Guttur Davenagere ckt-3 was going on. During the panelling work, while isolating LBB trip wires, trip pulse got extended and 220kV bus bar protection acted. GI-2 GI-1 III. Details of Trippings due to Failure or Non-operation of Auto-Reclose: Sl. No. Element Date & Time Reason Tripping of 400kV Gajwel - Narsarpur line Tripping of 400kV Jamalamadugu Kurnool-2 Tripping of 400kV Kurnool(PG) Kurnool(AP)-2 Tripping of 400kV Suryapet Shankerpally line-2 Tripping of 220kV Sedam-Tandur line Tripping of 400kV Suryapet Shankarpally line-2 Tripping of 220kV Regulapadu Alipur line. Tripping of 220kV Idukki-Udumalpet line at 03:55 hrs at 01:35 hrs at 02:03 hrs at 21:47 hrs at 00:50 hrs at 17:27 hrs at 06:00 hrs at 01:30 hrs at 19:27 hrs Tripped on B-phase to earth fault. Autoreclose attempt could not be validated with submitted DR of both ends and from PMU data plot. Line tripped on R-phase to earth fault. Protection did not attempt auto-reclose. Line tripped on B-ph to ground fault. A/R successful at Kurnool (AP) end & line was holding from Kurnool(AP). A/R unsuccessful at Kurnool (PG) end. Tripped on B-Phase to ground fault. A/R acted and unsuccessful at Suryapet end and A/R did not operate at Shankarpally end. Tripped on distance protection due to Y- Phase to ground fault. Auto reclosure could not be validated from the submitted DR/EL. Line tripped on B-Phase to ground fault. Auto-reclose attempt was unsuccessful at Suryapet end and Shankarpally end did not attempt A/R. Line tripped on B-Ph to earth fault. A/r was successful at Regulapadu and breakers at Alipura end got tripped. Line tripped on Y-phase to earth fault. Auto-reclose was successful at Udumalpet and breakers at Idukki did not Category Grid Occurrences to be discussed in the 69 th Meeting of PCSC scheduled to be held on 23 th November, /4 GI-2 GI-2 GI-2 GI-2 GI-2 GI-2 GI-1 GI-1

9 Annexure-I attempt auto-reclose and got tripped Tripping of 765kV Srikakulam Vemagiri line-2 Tripping of 400kV Krishnapatnam-Nellore line at 22:07 hrs at 22:22 hrs Line tripped on R-phase to earth fault. Line auto-reclosed successfully at Vemagiri and breakers tripped at Srikakulam. Line tripped on R-phase to earth fault. Auto-reclose was successful at Krishnapatnam and breakers at Nellore end got tripped. GI-2 GI-2 IV. Details of Trippings due to PLCC mal-operation: Sl. No. Element Date & Time Reason Category Tripping of 400kV VTS- Malkaram line-1 Tripping of 765kV Nizamabad Maheswaram line-2 Tripping of 400kV Kaiga-Guttur line at 13:33 hrs at 13:06 hrs at 07:50 hrs Tripped on direct trip receive on both ends Line tripped at Nizamabad end only on receipt of spurious Direct Trip. Line tripped on direct trip receive at both ends. Direct trip was observed in Kaiga end EL and DR of Guttur station. GI-2 GI-2 GI-2 ***** Grid Occurrences to be discussed in the 69 th Meeting of PCSC scheduled to be held on 23 th November, /4

10 Implementation of PCSC Recommendations (up to 67th Meeting) Meeting No / Index Details of Event Date & Time Reason PCSC Recommendations Utility responsible for Implementation Status of Recommendations as on Remarks Latest Status (To be filled up by the Constituent) Andhra Pradesh 52/I/2 (GD) Complete outage of 220kV Yerraguntla substation and tripping of running Units at Rayalaseema TPS at 10:39 hrs HV B-Ph Current transformer of 100MVA Power Transformer -1 failed resulting into a bus fault on 220KV Bus-1. Unit-1 and Unit-5 at RYTPS tripped during the fault at Yerraguntla substation 1. APGENCO to check associated logic for lube oil pump for correct operation under transient low voltage conditions at Rayalaseema TPS, Unit APGENCO to keep appropriate time delay/ fault ride through delay (typically 2 sec) in VFD speed sensor relay at all its generating Units including Rayalaseema TPS Units. APGENCO Mail received on : 1.The drop out relays of reducer oil pumps time setting was increased for all mills.so there will not be any trip under transient low voltage condition.- ---Complied 2.The recommendation regarding 2 sec time delay will be implemented during unit shut down and will be intimated immediately after implementation /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 hrs Triggering incident was snapping of Y phase conductor in 400kV Nellore (PG) - NPS line-1. Distance relay at Krishnapatnam end over-reached in Zone-1, and resulted in tripping of 400kV Krishnapatnam Nellore (AP) lines - 1&2 from Krishnapatnam end. Distance relay at MEPL overreached and resulted in tripping of MEPL-NPS line from MEPL end. APGENCO to furnish a report on the remedial action implemented w.r.t. overreaching of Krishnapatnam end distance relays during the tripping of 400 kv Nellore (PG) - NPS line-1 APGENCO 63/III.1 Tripping of 400kV Krishnapatnam- Nellore line at 05:16 hrs Line tripped on B-phase to earth fault and autoreclose was successful at Nellore(AP) end and unsuccessful at Krishnapatnam end 1. APGENCO/ SDSTPS to correct logic and ensure healthiness of A/R APGENCO scheme employed for transmission lines emanating from SDSTPS, and furnish an action taken report to PCSC forum. 2. APGENCO/ SDSTPS to configure DR s of line protection relays for a post triggering period of 2 sec to capture complete A/R operation at their SDSTPS. 63/III.3 Tripping of 400kV Krishnapatnam- Nellore line at 4:55 hrs R-phase to earth fault had occurred in line. Auto reclose was successful at Nellore, however protection at Krishnapatnam end issued a 3 phase trip 1. APGENCO/ SDSTPS to correct logic and ensure healthiness of A/R APGENCO scheme employed for transmission lines emanating from SDSTPS, and furnish an action taken report to PCSC forum. 2. APGENCO/ SDSTPS to configure DR s of line protection relays for a post triggering period of 2 sec to capture complete A/R operation at their SDSTPS. 67/II/11 Tripping of 400 kv Vijayawada TPS at Triggering incident was failure of Y-ph CT occurred in 1. APGENCO to provide a time delay of 100 msec for OVR, Stage-II APGENCO Malkaram and Vijayawada TPS Suryapet 19:33 hrs 400 kv VTPS-Malkaram feeder at VTPS end. protection operation for all 400 kv lines at their 400 kv VTPS station. 2. APGENCO to rectify the issues relating to non-sending of DT to Suryapet end on operation of OVR, Stage-II operation and Tie-CB LBB operation at VTPS end. 3. APGENCO to configure DT send/ receipt event in their end DR s and EL s on all 400 kv lines emanating from 400 kv VTPS station. 56/II/13 Tripping at 220kV Gooty Substation of APTRANSCO at 16:04 hrs 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 APTRANSCO mail dated on : To avoid the unwanted malopeartions due to the external LBB trip initiation from PGCIL, Vide 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. Page 1 of 35

11 signals to the Central Unit. 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 64/II/1 Tripping of 400/220KV 315MVA ICT and 230kV elements at 400kV Vemagiri at 12:31 hrs substation of APTRANSCO Suspected mal-operation of Busbar protection had caused tripping of 220kV Bus-1 at Vemagiri. APTRANSCO to furnish a report on the remedial action taken along with single line diagram of 400/220 kv Vemagiri SS indicating fault location and CB's involved and protections operated. APTRANSCO APTRANSCO mail dated bus bar protection scheme and cables from LBB relay to BBP panel were checked throughly and found ok. 58 Provision of line differential protection for Jurala line 1 & 2 (line length-1.45 KM) feeders at 220 kv Jurala HPS [Carry-Over from Protection Audit Recommendations] TSGENCO The issue was discussed in PCSC-58 meeting held on , when PCSC forum agreed to de-link the implementation of the Item from the scope of Protection Audit Recommendations (PAR), and pursue it as part of PCSC Recommendations. Telangana TSGENCO mail dated Procurement of Differential Protection relays is under process and the work will be completed by the end of November TSGENCO mail dated Procurement of Line Differential Protection Relays is under process and the work will be completed by the end of January /III/5 Tripping of 400 kv Khammam - KTPS line at 10:52 hrs Line tripped on B-phase to earth fault. First fault was persistent for 380 ms. Auto-reclose was successful at Khammam end during 1st fault. 2nd fault occurred during re-claim time of breaker hence Khammam end breakers also got tripped. 1. TSGENCO to implement the SRPC agreed philosophy for Power Swing Blocking in all distance relays on the feeders emanating from KTPS. 2. For the line under consideration, TSGENCO to consult relays OEM to migrate to new versions of Firmware (from to ) and Pset (to ). TSGENCO TSGENCO mail dated : 1. According to SRPC phylosphy power swing block settings are changed to ALL ZONES BLOCK EXCEPT ZONE Completed 2. M/s. Siemens is requested to depute the service Engineer to update the firm ware of existing SIPROTEC relays in 400KV switch yard. This work will be completed on or before /IV/3 Tripping of 400 kv Gaiwel-Hyderabad at line tripped on direct trip receive at Gajwel and was For the line under consideration, the following shall be carried out by TSTRANSCO TSTRANSCO mail dated on : line 12:16 hrs holding from Hyderabad TSTRANSCO in coordination with PGCIL (SR-I): (i) End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends. (ii) Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components shall be repaired/ replaced. (i) Letter is been given to field for conducting end to end testing of 400kV Gajwel-Ghanapur line. (ii) Healthiness of PLCC system components will be checked while conducting end to end testing. TSTRANSCO mail dated on : 1. Letter is been given to field for conducting end to end testing of 400kV Gajwel-Ghanapur line. 67/III/1 Tripping of 400 kv Gajwel at Line tripped on B-ph to earth fault. Auto-reclose was 1. For the line under consideration, TSTRANSCO to sort-out A/R TSTRANSCO Bhoopalapalli line 13:13 hrs successful at Bhoopalapally end and breaker tripped at related issues at Gajwel end. Gajwel. 2. For the line under consideration, TSTRANSCO to configure EL at Gajwel such that PDR operation is also captured in it. 3. TSTRANSCO to configure DR s of protection relays at their Gajwel SS for a post-triggering period of 2 sec so as to capture complete A/R operation. Page 2 of 35

12 62/IV/5 Tripping of 400 kv Gajwel- Bhoopalapalli line at 15:00 hrs Line tripped at Bhoopalapally on DT receive and was holding from Gajwel. For the line under consideration, TSTRANSCO to carry out the following in coordination with TSGENCO: (i) Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components shall be repaired/ replaced. TSGENCO / TSTRANSCO TSTRANSCO mail dated on : 1. Letter is been given to field for conducting end to end testing of 400kV Gajwel-Bhoopalpalli-1 line. (ii) End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends. (iii) Frequency bandwidth tuning of PLCC link for faithful transmission of signals shall be carried out. Page 3 of 35

13 Karnataka Page 4 of 35

14 38/GD/3.5 GD-1 at Kadra and Kodasalli hydro power station at 19:31hrs A fault had occurred in 220 kv Kadra and Kodasalli. 1. The PCSC forum requested KPCL to speed up the installation of As A result, de-energization of 220kV bus occurred at Numerical Distance Protection relay in Kadra Kaiga and Kadra and Kodasalli. Kodasalli Kaiga. 2. The PCSC forum requested KPCL to submit the implementation status of PSAG-10 recommendations within a week s time. KPCL Mail recieved on : 1) e-nit floated on for procurement of Numerical distance relays & GPS. As there is change in scope of work and quantity of relays by more than 25%, which is not permitted as per KTPP act. Hence, tender cancelled and refloated on with revised scope of work and revised PQR. 2. However, as per the recommendations of PSAG, Relays were temporarily rearranged, replaced and wired up. testing & commissioning shall be completed with the assistance of KPTCL. Mail recieved on : 1. Cover -1 of the bid is scheduled for open eing on As per the recommendations of PSAG, Relays were temporarily rearranged. testing & commissioning completed with the assistance of KPTCL. Mail recieved on : NIT floated on through e-portal. Bid evaluation completed. Obtaining of Administration approval to place P.O is in progress. However, as per therecommendationsof PSAG-10, Relays weretemporarilyrearranged.testing & commissioning completed with the assistanceofkptcl. Mail recieved on : NIT floated on through e-portal. Bid evaluation completed. LOA's issued to M/s Schneider Electric Infrastructure Ltd. on Mail recieved on : LOA's issued to M/s Schneider Electric Infrastructure Ltd. on Engineering work is in progress. Status informed during Special Meeting held on : LOA s issued to M/s Schneider on Inspection of relays completed and received at site. DI issued for all balance materials except furnitures. Status received vide KPCL mail dated : Numerical Distance Protection relays commissioned on for all 4 lines at Kadra PH. Installation, Testing and commissioning of Numerical Distance Protection Relays for all the 4 outgoing lines is completed in all respect at Kodasalli power house. 41/I/1 GD-1 at 220kV Kadra power Station of KPCL at 12:56 hrs Triggering incident was B-phase to earth fault had occurred in 220kV Kadra-Kodasalli line. Line tripped from Kodasalli end only. 220kV Kaiga-Kadra tripped in Zone-3 from Kaiga end. Tripping of evacuating lines caused bus shut down at Kadra hydro station. 1. KPCL to make functional the Main2 (EPAC) relay with the help of KPTCL at the earliest. 2. KPCL to investigate the reason for DC fuse fail during transient fault in 220kV Kadra-Kodasalli line including the testing/ checking of DC supply cables, breaker control cables, and trip coils. KPCL Mail received on : 1. Main-2 relays already installed and commissioned. 2. DC fuses are intact. Till date no such incidence occurred. 3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be reviewed. 3. KPCL to ensure supply for Main-1& Main-2 protections, Trip Coils (TC1, TC2) from separate battery banks. Mail received on , and : 1. Completed. 2. Completed. 3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be reviewed. Status received vide KPCL mail dated : 1. Completed. 2. Completed. 3. Providing 2 separate DC sources is under process Page 5 of 35

15 46/II/21 Trippings at 220kV Raichur TPS at 01:35 hrs 1. KPCL to check the operation of anti-pumping relay on 220 kv side and keep it in healthy condition. 2. KPCL to provide manual reset to the 220 kv side master trip relay. 3. KPCL to use both the 220 kv buses as main buses under normal operation, and should go for single bus operation only during emergencies. KPCL Mail received on : 1) Anti-pumping contactors of all the nine 220KV Lines are in circuit and tested periodically during AOH works of lines along with other protections. 2) Completed. 3) Possibility to use both the 220kV buses as main bus under normal operation is under review. Mail recieved on : 1) Completed 3) Two bus operation for 220kV buses : In place of existing CT switching relays, High speed manual heavy duty change over switch of sufficient current capacity will be retrofitted to all feeders at 220kV station and same will be operated manually during changeover of feeder by one bus to the other and this arrangement may facilitate to put both buses in service. Time required for this retrofit is around 90days. However, this work will be taken up only after retrofitting of electromagnetic relays with numerical relays for Main-2 protection of all 220kV lines, for which work is in progress. Status received vide mail dated : 1) Completed. 2) Completed. 3) Two Bus operation for 220kV bus is being carried out whenever required. However scheme for tripping of one bus during LBB/fault and maintaining the other bus intact by tripping B/C breaker will be taken up in R&M works. 49/II/15 Trippings at Raichur TPS at 00:30 hrs Running Unit-4, 5 and Unit-8 and 400kV RTPS- Yeramaras TPS feeder got tripped due to deenergization of both 400kV Bus-1&2 at Raichur TPS 1. KPCL to carry out hot-line washing of RTPS-connected lines regularly to avoid trippings due to fog and dust. 2. KPCL may see the feasibility of providing breaker flashover protection at RTPS, and implement the same if possible. KPCL Status informed during Special Meeting held on : 1. Hot line washing was done previously.tender process is on for silicon coating of insulators. Status received vide mail dated : 1. Off line water washing is being carried out whenever the Unit or Line is under shutdown. Silicon coating for Unit#8 main & tie breakers carried out in Sep'16 and same is under observation. Till today in order and good condition. For remaining breakers, since it is big order, approval for the same is under process. 2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker flash over protection feature will be enabled (if available) in the numerical relays which will be retrofitted in phased manner during R&M works. 54/I/4 Tripping of Nagjheri Generators at 12:29 hrs 220 kv Nagjheri - Bidnal line tripped on B-E fault at 12:28 Hrs. At the same time, five running generating units (1, 2, 3, 4 & 6) at Nagjheri tripped on operation of Generator Transformer s back-up Over Current & Earth Fault protection. 1. KPCL to revise the settings of GT s back-up O/C and E/F protections considering their individual contribution to solid bus fault at 220 kv bus of Nagjheri PH. 2. KPCL to upload/ make available various tripping files (FIR/DR/EL/TR) for all tripping involving their stations in compliance of IEGC Regulation 5.2 (r). KPCL Status received vide KPCL mail dated : 1. GT backup overcurrent & earth fault settings are revised as per the recommendations of our head office CEED,Bangalore, copy of letter enclosed. 2. FIR/DR/EL/TR are being uploaded in the recent incidences as all the main-2 relays are replaced with new numerical relays 54/II/4 Tripping of 400 kv Raichur TPS- Mahboobnagar line at 10:23 hrs Line tripped on operation of Backup impedance protection of line reactor. Direct trip was received at Mahboobnagar end. KPCL to keep the functioning of the concerned electro-mechanical back-up impedance protection relay under observation, and replace it with a spare at the earliest. KPCL Status received vide KPCL mail dated : The electro-mechanical back-up impedance protection relay is in service. However, Budgetary offer obtained for the retrofitting of Line reactor protection with Numerical relay and is under process 54/II/9 Tripping of 400kV Raichur TPS Bus at 21:12 hrs Y-ph Pole of Tie-breaker of Unit-4 at RTPS failed. 1.KPCL to undertake the following remedial measures to avoid Unit-4 got tripped on operation of Generator breaker flashovers: Differential, Reverse power & LBB protection. (i) Replacing all porcelain insulators with composite insulators Operation of LBB protection led to tripping of BUS-2 (ii) Carrying out hot-line water washing of all insulators on regular at RTPS basis. (iii) Applying Room Temperature Vulcanizing (RTV) Silicone high voltage insulator coatings to all bus-connected ceramic insulators of equipment like CT, PT, CB, Isolators etc. 2.KPCL to take steps to provide dedicated breaker flashover protection to all breakers at Raichur TPS at the earliest. KPCL Status received vide KPCL mail dated : 1. i) Silicon coating for Unit#8 main & tie breakers carried out in Sep'16 and same is under observation. Till today in order and good condition. For remaining breakers, since it is big order, approval for the same is under process. ii) Hot line water washing stopped and off line water washing is carried out whenever the 400 KV Unit or line is under tripped condition / Shutdown condition. 2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker flash over protection feature will be enabled (if available) in the numerical relays which will be retrofitted in phased manner during R&M works. Page 6 of 35

16 54/II/13 Tripping of Units at Raichur TPS at 15:36 hrs During testing of retrofitted distance protection in 400kV Raichur-2 feeder, LBB protection trip DC got extended to Bus trip. This resulted in tripping of 220kV bus at RTPS and all connected 220 kv elements. Unit-4 which is connected to 400 kv Bus got tripped due to tripping of Station Utility Transformer that is connected 220 kv bus In view of the availability of two buses along with healthy buscoupler at 220 kv RTPS, KPCL is recommended to put in service the double-bus operation at 220 kv RTPS by suitably distributing loads within 15 days. KPCL Status received vide KPCL mail dated : Two Bus operation for 220kV bus is being carried out whenever required. However scheme for tripping of one bus during LBB/fault and maintaining the other bus intact by tripping B/C breaker will be taken up in R&M works. 55/II/1 Multiple tripping at 400 kv Raichur TPS Station at 21:44 Hrs Triggering incident was failure of R-phase CT of 400/220kV ICT kV YTPS-RTPS line got tripped from YTPS end. 400kV RTPS- Mehaboobnagar line tripped on a B-phase to earth fault. 1.KPCL to enable zero-sequence compensation feature, if not already done, in all differential relays of transformers at RTPS. 2.KPCL to examine in detail the reasons for SOTF operation at RTPS end for the fault on RTPS-Veltoor line, and if required relay (configuration) settings at RTPS end may be suitably got revised with the help of their OEM. KPCL Status received vide KPCL mail dated : 1) Zero-sequence compensation feature is already enabled in all the differential relays of transformers. ---Completed 2) Referred to OEM for the tripping of line on SOTF protection. 3) Action has been taken to retrofit the protection relays of tie bays of Mahbubnagar and Munirabad line to enable Auto-reclosure function. 3.KPCL to take steps to enable auto-reclose for the Tie-CB s in the dias containing Munirabad and Veltoor (Mehboobnagar) at RTPS. 55/II/19 Tripping of 400kV Bellary TPS- Yeramarus TPS line and 400kVYeramarus TPS - Raichur TPS line at 17:21 hrs Direct Trip was sent from YTPS to RTPS and BTPS 1.KPCL to properly configure the distance relays at YTPS end on both YTPS BTPS line and YTPS-RTPS line with specific focus on reaches and timings of Zone-2, Zone-3, and Zone-4 (reverse). 2.KPCL to ensure the healthiness of Direct Trip circuits and relay coils at YTPS. KPCL 3.KPCL to ensure time sync of DR s and EL s at YTPS with GPS. 56/I/2 Complete outage of 220kV Sedam Substation of KPTCL at 15:27hrs 220kV Sedam-Humnabad-2 tripped at Sedam on KPCL to disable GFC protection on all lines emanating from their Distance protection, Zone-2. Sedam-RTPS-1 &2 lines generating stations. tripped at RTPS end only. 220kV Tandoor inter-state line was hand tripped due to incoming supply failure KPCL Status received vide KPCL mail dated : As per the reccomndations of KPTCL in Feb'16 the settings are done with a time delay of 2 secs. 57/II/3 Tripping of 400/220 kv ICT-2 at Raichur at TPS 3:32 hrs ICT-2 tripped on operation 400/220KV ICT-2 was tripped on operation of 220KV side Instantaneous over current protection during B-phase to earth fault in 220kV RTPS-Sedam-II line. KPCL to review appropriately the high-set of ICT s back-up O/C protection at their 220 kv RTPS so that they do not operate for a normal through fault. KPCL Status received vide KPCL mail dated : The settings will be reviewed in co-ordination with KPTCL & OEM. 58/I/2 (GD) Complete outage of 220 kv Nagjheri PH at of KPCL. 12:47hrs Bus dead occurred at 220kV Nagjheri PH due to tripping of evacuating lines. (i) KPCL to disable high-set operation of DEF relays (ii) KPCL to block DEF relays whenever corresponding distance protection relays pick up at Kodasally end on Nagjheri Kodasalli lines, and (iii)kpcl to provide stand-alone Event Logger at their 220 kv Nagjheri PH. KPCL Status received vide KPCL mail dated : 1. DEF settings in lines are made as per recommendations of CE(RT) & R&D, KPTCL, Bangalore & EE(RT), KPTCL Hubli. High set operation of DEF relays is disabled at Kodasalli end. 2. All these guidelines are incorporated by KPTCL during the replacement of line protection relays. 3. New stand alone event logger is to be procured since spares for old stand alone event logger are obsolete. 58/I/3 (GD) Complete outage of 220 kv Kadra power station of KPCL at 14:40 hrs LBB of 220kV Kodasalli breaker at Kadra end got operated which resulted in tripping of Bus at Kadra and in turn led to tripping of all elements (i) KPCL to check settings of LBB protection in all relays from which it was implemented, and ensure that their configuration, logic, and timing are in order at their 220 kv Kadra PH. (ii) KPCL to furnish details regarding the existing LT auxiliary supply arrangement at their 220 kv Kadra PH, and take steps to provide a suitable Auto-Main-Fail (AMF) panel for DG set to effect its auto-starting in case of failure of LT supply. (iii) KPCL to ensure time-sync of all relays (DR s & EL s) with GPS at their 220 kv Kadra PH. (iv) KPCL to provide stand-alone Event Logger at their 220 kv Nagjheri PH. KPCL Status received vide KPCL mail dated : 1. All logics checked and found normal. LBB timing checked and found 200msec as per KPTCL MRT recommendation. - Completed 2. Work Under Progress 3. New GPS System commissioned along with new numerical and synchronised with GPS system - Complied 4. Work Under Progress Page 7 of 35

17 58/I/5 (GD) Complete outage of 220 kv Sharavathy Tail Race PH at 11:19 hrs Spurious operation of LBB protection of line feeder had led to tripping of 220 kv bus at Sharavathy Tail Race power house. (i) KPCL to ensure the integrity of the connecting cable/ conductor from Generating Unit-3 to its corresponding GT breaker at their STR PH. (ii) KPCL to ensure the healthiness of Manual Current Regulator (MCR) of Unit-3 s AVR at their STR PH. (iii) KPCL to ensure the healthiness of AVR s of all Units of STR PH. (iv) KPCL to provide stand-alone Event Logger at their 220 kv STR PH. KPCL Status received vide KPCL mail dated : 1. On at STRP,Two units were running(unit-3 & Unit-4.It is to clarify that, Station tripped due to spurious operation.lbb relay in Unit-4 and not due to operation of Unit-3 LBB as indicated in PCSC recommendations.unit-3 which was in service tripped as a consequence of LBB Protection.How ever, following actions performed in both Units. a) Trip coil-1 and Trip coil-2 circuit (including cable from protection panel to GCB Marshaling Box)of GT Breakers of Unit 03 and 04 checked found ok. b) Integrity of Connecting cable/conductor from Generating unit no.3 and also to its corresponding GT Breakers inspected and found ok. c) Regarding Spurious operation of Unit No.04 LBB relay and its timer.checked the operation of the LBB overcurrent relay with its external Timer for repeated correct operations, it was found that LBB Timer was giving correct timing operation for 1 in 3 operations only i.e. for one of the operation it was operating within 40ms compare to set value(200ms) hence declared as faulty and the same has been replaced with new one later operation of the new Timer checked and found ok.operating for >200mse only. With this cause for spurious operation of LBB and resulting in complete outage of STRP has been identified and solved Completed 2. In Unit -3,MCR is working satisfactorily.it is to clarify that problem was existing in Unit No.4 AVR manual channel reference value of Generator.The Same has been replaced with spare one. Manual channel AVR is found to be Ok Completed 3. All the units AVR's Healthyness checked and found Ok Completed 4. Presently at GPH,no stand alone Event logger exists. Since the subject requirement pertains to all the Generating units and in view of Standardization of the complete system, Networking of numerical relays carried out and events are availble in networking system.. 58/I/6 (GD) Disturbance in Kerala system at Partial disturbance occurred in central Kerala grid due (i) SLDC, KSEB to put in place proper mechanism to ensure adequate KPCL 14:47 hrs to overloading and tripping of 220 kv lines. Loss of infeed load-generation balance is maintained in their control area at all to 220 kv Kalamassery, 220 kv Brahmapuram, times, and due vigilance is exercised in operating an already depleted 220 kv Ambalamugal, 220 Pallom & 220 kv Kochi transmission network. occurred. Generation at Neriamangalam, Panniar, Chengulam and Pallivasal also got affected during the (ii) KSEB to put UFR in service at New Pallom end on 220 kv New incident. Pallom Amabalamugal line as part of Kudankulam Regional Islanding Scheme. 58/I/7 (GD) Complete outage at Varahi Hydro Power at Station 14:06 hrs LBB protection operated and caused bus shut down at Varahi PH (i) KPCL to check and correct configuration settings of LBB protection in all relays from which it was implemented, at their 220 kv Varahi PH. (ii) KPCL to provide stand-alone Event Logger at their 220 kv STR PH. KPCL Status received vide mail dated : LBB Protection system is in Bus bar Protection Panel.The Configuration settings are checked.they are as follows. Minimum operating primary current is 160A Stage I:Issue of Retrip to the feeder is 100ms after the action of main distance protection Relay/initiation of LBB. Stage II:Bus bar LBB Trip -200ms. Total time of LBB trip is 300ms from the time of occurrence of Line Fault. 62/I/1 Complete outage of 220 kv Nagjheri substation of KPCL at 00:38 hrs Triggering event was the fault on 220 kv Nagjheri Kodasalli line-2. Both buses of 220 kv Nagjeri (i) KPCL to adopt the following VT fuse-fail logic for all 220 kv lines emanating from NPH: KPCL Status received vide mail dated : power station of KPCL got Under VT fuse fail condition, distance protection shall normally be de-energized. kept blocked. However, upon detection of a fault (sensed by negative sequence component), blocking of distance protection shall give rise to operation of its inherent Over-Current protection set with a definite time delay of 500 msec. (ii) KPTCL/ KPCL to revise Zone-2, Zone-3 and Zone-4 (reverse) timings of DPR of all 220 kv lines emanating from Nagjheri PH in line with Ramakrishna Committee guidelines. 1. Already settings are discussed with EE(RT), Hubli and soon relays will be tested for VT fuse fail condition. 2. Timings of Zones were set as per the recommendations of CE(RT) & R&D, KPTCL, Bangalore & EE(RT), KPTCL, Hubli.Regarding revision of timings will be carried out in co- ordination with EE(RT), KPTCL, Hubli. Page 8 of 35

18 63/II.10 Multiple trippings at 400 kv RTPS substation of KPCL at 01:18 hrs Bus-2 B-Ph differential bus bar protection operated at 400 kv RTPS end, tripping all the main breakers connected to Bus-2 1. KPCL to start furnishing FIR and TR of their tripping events as per the formats provided by SRLDC. 2. KPCL to check earth-mat resistance for 400 kv switchyard and ensure that it is within prescribed limits. KPCL Status received vide mail dated : 1. Furnishing FIR & TR of the tripping events as per the formats provided by SRLDC. 4. Refered to OEM for the tripping of Tie CB of Munirabad line on SOTF protection. 3. KPCL to set right operation of SER in C&I Control Room of Unit KPCL to furnish action taken w.r.t. tripping of Tie-CB of Munirabad line on SOTF protection. OEM report, in this regsrd, may be furnished. 65/II/9 Tripping of 400/220 kv ICT-1 at BTPS at 19:41 hrs ICT-1 got tripped on operation of LV side earth fault protection during R-phase to earth fault in 220 kv BTPS-Lingapur line 1. KPCL to review the need for providing separate non-directional sensitive earth fault protection for ICT s at their BTPS station, and take steps to disable the same. 2. For 220 kv BTPS Lingapura line, KPCL to resolve issues relating to PLCC carrier communication, and put A/R into service. KPCL 65/III/2 Tripping of 400 kv Hiryur-BTPS line at 14:01 hrs Y-phase to earth fault had occurred in line. Direct trip was sent from BTPS to Hiryur end. KPCL to introduce suitable delay (say, 3 sec) for UVR tripping, and disable sending of DT to the other end on UVR operation at their BTPS station. KPCL 66/ III/ 1 Tripping of 400 kv BTPS-YTPS line at 19:48 hrs R-phase to earth fault had occurred in line. Line did not auto-reclose from both ends. For the line under consideration, KPCL to carry out the following: (i) End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends. (ii) Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components shall be repaired/ replaced. KPCL 67/I/5 Complete Outage of 220kV Nagjheri Power House at 19:51 hrs While desynchronizing Unit-3, R-ph of Generator Circuit Breaker did not open due to mechanical problem. This resulted in operation of LBB protection of Unit-3 CB and this tripped all the six lines. 1. KPCL to avoid hand-tripping of their running units in one section whenever BBP operation takes place in the other section of the bus, and resort to generation back-down in consultation with SLDC. 2. KPCL to see the possibility of using full-fledged Double Main-Bus system with four sections instead of the present Single Main-Bus with two sections. KPCL 38/GD/3.1 GD-1 at Mahalingapura Substation of KPTCL Fault had occurred in 220kV Mahalingapura-Narendra line-2. Due to the failure of relay operation at Mahalingapura, breakers at remote end tripped which resulted in bus dead condition. 1. PCSC forum recommended KPTCL to replace the old static distance protection relays with numerical relays. 2. PCSC forum also requested KPTCL to provide a broken conductor alarm indication in Control Room. 3. Standing instruction needed to be given to the all substation personnel for not changing the relay settings without approval of RT/MRT wing. KPTCL Mail received on (KPTCL) & : 1.Existing Back up relays will be replaced by numerical type distance relays.procurement is in tendering stage. 2. Completed. 3. Completed. KPTCL Mail recieved on : 1. Existing back up relays will be replaced by Main-2 protection. LOI issued M/s Alstom for taking up the works. KPTCL Mail Recieved dated : Under the Scope of R&U. The work will be taken up by M/s Alstom shortly. KPTCL Mail Recieved dated : 1. ALSTOM make P442 type Numerical relays are supplied to the site, replacement of M-1 relays(optimho) by new relays will be taken up shortly Page 9 of 35

19 39/I/5 Tripping of 400/220kV ICT-2 at Hoody substation of KPTCL Suspected mal-operation of 220kV side Rphase over current relay 1. PCSC forum recommended KPTCL to replace the relay with a different make. 2. KPTCL was also requested to train the O&M personnel adequately before performing any maintenance works to avoid such unwanted trippings. KPTCL Mail received on & : 1. C&R panels of 500MVA ICT 1&2 will be replaced under scheduled R&M works. 2. O&M personnel are instructed to take sufficient care in order to avoid unwarrented trippings. --- Completed. KPTCL mail received on : 1. New C&R panels(with numerical relays) erected for 500MVA ICT-1 &2 under R&M work, which will be commissioned shortly. KPTCL mail received on : 1. New C&R panels(with numerical relays) erected for 500MVA ICT-1 &2 under R&M work, which will be commissioned shortly. KPTCL mail received on : 1. New CRPs mounted in bay KIOSK commissioned under R&M works. 40/I/1 GD-1 at 220kV Ambewadi Station of KPTCL at 21:22 hrs Triggering incident was B-phase to earth fault in 220kV Ambewadi- Nagzari line-1. B-pole of breaker did not open at Ambewadi end. LBB protection not available at Ambewadi end. All elements tripped on Zone-2 from remote ends. 1. Till the completion of R&M works for bus bar and LBB protection, KPTCL shall explore the possibility of having split bus operation at Ambewadi and submit the details of the same to PCSC forum. 2. KPTCL shall provide the details of the tripping of Supa hydro station connected downstream from 110 kv bus. KPTCL Mail received on : 1. In view of operating 220kV Ambewadi SS in split bus mode, action is being taken up by KPTCL. Problem in the 220kV bus coupler breaker is attended and isolator overhauling work is under progress. Spilt bus operation at Ambewadi will be made possible at the earliest. 2. ICT Protection system at Ambewadi and trippings occured at Supa GS during the instance is checked up and remedial measures already furnished in this regard Completed Mail recieved on : 1. Action is being taken by KPTCL for operating Ambewadi in split bus mode. Problem in bus coupler breaker is attended.isolator overhaulling work is completed.pts are already provided to 220kV Bus-II. After commissioning of Bus-II PTs, Ambewadi can be operated in split bus mode. works will be completed within a months time. KPTCL mail recieved on : 1. Bus-II PTs yet to be commissioned.planned to complete before end of April KPTCL mail recieved on : 1. Yet to be attended 40/IV/1 220kV Sedam- Tandur line at 22:20 hrs Line tripped on Yphase to earth fault from both the ends KPTCL was requested to explore the possibility of providing A/R feature to this line and submit the remedial measures to the PCSC forum. KPTCL Mail recieved on : Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring the carrier protection, AR will be enabled. KPTCL mail recieved on : Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam end. After restoring the carrier protection, AR will be enabled. KPTCL mail recieved on : SEE,SCADA to update the latest status KPTCL mail recieved on : Action is being taken to restore carrier protection.ar will be enabled once carrier signal is restored. Page 10 of 35

20 41/I/4 Complete outage at 220kV Sedam Substation of KPTCL (GD-1) at 8.00 hrs R-Phase to ground fault occurred on 220kV Sedam- 1. KPTCL to provide Bus bar and LBB protections for 220 kv Shahpur line. Fault not cleared from Sedam end due to bus at Sedam S/s. stuck-breaker condition. While the Sedam- Sahapur 2. KPTCL to implement A/R feature on 220 kv Sedam-Tandur line tripped from Shahapur end in Zone-1, the other inter-state line. 220 kv lines from Sedam tripped at remote ends in Zone-2. This caused complete outage of 220kV Sedam substation. KPTCL Mail received on : Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being taken to restore the carrier protection for 220kV Sedam- Tandoor line. AR will be enabled. Mail received on : 1. Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being taken to restore the carrier protection for 220kV Sedam- Tandoor line. AR will be enabled after restoration of PLCC. KPTCL mail received on : 1. Bus bar protection panels pocured and erected at Sedam. Wiring, testing,commissioning is being taken up.planned to complete by April Action is being taken to restore the carrier protection for 220kV Sedam- Tandoor line. AR will be enabled after restoration of PLCC. 42/I/1 (GD) Complete outage of 220kV Sedam substation of KPTCL at 14:24 hrs Fault occurred in 220kV Sedam-Shahpur line 1. KPTCL to provide Bus Bar protection and LBB protection at Sedam S/s and furnish the status of their implementation to PCSC forum. KPTCL Mail received on : 1. Bus Bar protection will be provded under R&U. 2. A/R yet to be enabled. 2. KPTCL to implement A/R feature on 220 kv Sedam-Tandur interstate line. Mail received on : 1. Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being taken to restore the carrier protection for 220kV Sedam- Tandoor line. AR will be enabled after restoration of PLCC. 42/I/2 (GD) Complete outage of 220kV Ambewadi substation of KPTCL at 7:51 hrs Fault in 220kV Ambewadi-Nagjheri line-2 1. KPTCL shall provide A/R feature on Ambewadi Ponda 220 kv D/C inter-state line. 2. Till the completion of R&M works for bus bar and LBB protection, KPTCL shall explore the possibility of having split bus operation at Ambewadi and submit the details of the same to PCSC forum. KPTCL Mail received on : 1. Procurement of Bus bar and LBB protection is in the final tendering stage. 2. Action is being taken to restore the carrier protection for 220kV Sedam- Tandoor line. AR will be enabled after restoration of PLCC. 47/II/13 Tripping of Unit-1&2 along with 400/220kV ICT-2 at Raichur TPS at 4:51 hrs 220kV RTPS-Lingasugur line-2 tripped at TPS end on KPTCL to activate non-directional Over Current protection with a operation of distance time delay of msec for Fuse protection zone /220kV ICT-2 got tripped on failure condition at Lingasugur. operation of earth fault protection. 220kV RTPS-Lingasugur line-1&3 tripped on distance protection zone-2 and zone-3 respectively. Due to tripping of ICT-2, the running units got overloaded and it was mentioned that under frequency occurred as units are on load control. The Units got tripped on under frequency. KPTCL Status received vide KPCL mail dated : LV earth fault relay had an additional default E/f setting having a definite time which resulted in tripping of ICT-2 and the same was rectified and already complied. 48/I/2 (GD) Complete outage of 220kV Peenya at All connected 220kV lines and transformers were KPTCL to revise distance relay settings at Nelamangala end for 220 KPTCL Substation in Karnataka 4:23:17 hrs taken on 220kV North bus as South bus was under kv Nelamangala Hebbal - Peenya line 1 for the effective line shut down for conversion of strung bus to rigid bus length of 17 km. These new settings can be appropriately reviewed as and isolator replacement under R&M works. Failure and when the tie-arrangement at Hebbal is done away with. of HV side Y phase CT of 150MVA Transformer-3 occurred at Peenya Substation which resulted in operation of Differential and HV REF protection. The failure of CT also resulted in a 220kV bus fault in 48/I/3 (GD) Outage of 220kV Ambewadi station in Karnataka at 10:41 hrs North Bus. 220kV Ambewadi-Nagjheri line-2 tripped on B-phase KPTCL to fast-track providing A/R on all 220 kv lines emanating to earth fault. This resulted in loss of supply to 220kV from Ambewadi SS to prevent Station shut-down on temporary faults. Ambewadi bus. 220kV Ambewadi-Ponda line-1&2 were hand tripped after deenergization of bus at Ambewadi. KPTCL KPTCL mail received on : Presentl 220kV Nelamangala -Hoody(i.e. nelamangala-peenya-hebbal - Hoody line is made LIILO at Yelahanka sub station and breaker at Peenya is kept open, necessary modification in distance relay settings adopted for new configuration. KPTCL mail received on : Will be complied in a months time. Page 11 of 35