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उ र के्षत्रीय िवद्युत सिमित

18-ए, शहीद जीत िसंह मागर्, कटवािरया सराय नई िद ली – 110016 Government of India

Northern Regional Power Committee 18-A, Shaheed Jeet Singh Marg, Katwaria Sarai, New Delhi-110016

No. NRPC/OPR/107/01/ Dated: 14.08.2014 FAX MESSAGE From : Superintending Engineer (O), NRPC. To : Members of Protection Sub-Committee

1. Director (P&C)/BBMB, Chandigarh, Fax-0172-2652054 2. General Manager (O&M) DTL, New Delhi, Fax-23221059 3. GM (O&M), Delhi Transco Limited, New Delhi, Fax-011-23236462 4. GM (T), Common Services IPGCL, New Delhi, Fax-23370247 5. Chief Engineer (TS), HVPNL, Panchkula, Fax-0172-2591244 6. SE (M&P), HVPNL, Dhulkote , Haryana, Fax-0172-2540014 7. SE (Tech).,HPGCL,Fax-0172-5022436,SE(O&M-VI),Panipat Fax:0180-2566768 8. Chief Engineer (Transmission), HPSEB, Hamirpur, Fax-01972-223435 9. Chief Engineer (Comml. & Survey Wing) PDD, Jammu, Fax-0191-2474233 10. Chief Engineer (P&M), PSTCL, Ludhiana, Fax-0161-2741280, 2451491 11. CE (M&P), RRVPNL, Jaipur, Fax-0141-2291891 12. SE (Electrical), RRVUNL, Suratgarh, (Rajasthan), Fax-01509-245299 13. Superintending Engineer (T&C), UPPCL, Meerut (U.P.), Fax-0121-2666062 14. Chief Engineer, (L-2), UPRVUNL Lucknow, Fax-0522-2287822, 2287880 15. DGM (T&C), PTCUL, Dehradun, Fax-0135-2760331 16. Chief Engineer (O&M), NHPC, Faridabad, Fax-0129-2272413 17. NPCIL (i) Maintenance Superintendent, NAPS, Narora, Fax- 05734-222167 (ii) Maintenance Superintendent, RAPS, Rawatbhata, Fax- 01475-242060 Chief 18. GM (O&M) NR – I, PGCIL, New Delhi, Fax-011-26601079 19. GM (O&M), NR-II, PGCIL, Jammu, Fax-01951-237186 20. Chief Manager (TS), N.R.L.D.C, New Delhi, Fax- 011-26852747 21. GM (OS) NTPC Ltd., Noida, Fax-0120-2410082, 2410068 22. DGM (Maintenance), SJVNL, New Shimla, Fax- 0177-2673283 23. DGM (O&M), THDC India Ltd., Tehri Garhwal, Fax No 01376-236305 24. Director (GM division), CEA, New Delhi, Fax-011-26109750 25. General Manager, APCLP, Fax No. 01251-266326

26. Director JPPVL, Fax- 0120-4516201/4609464/4609496 27.Assistant Vice President, BRPL, Fax- 39996055, 39999765 28. GM (Production), Jhajjar Power Ltd., Fax- 01251-270155 29. Managing Director, APL, Fax No. 0124-2555342

…................................................................................................................................... Sub:-Minutes of the 26th Protection sub Committee Meeting. The 26th Protection Sub-Committee Meeting was held on 23rd May, 2014 at NRPC sect., New Delhi. The minutes of this meeting are available on NRPC website at http://www.nrpc.gov.in Sd/- (Ajay Talegaonkar)

SE (Operations) & Member Convener PSC

Summary record of discussions held in the 26th Protection Sub-Committee meeting held on 23rd May, 2014 at NRPC sect., 2014

The list of participants is enclosed at Annexure-I. A.1 Confirmation of minutes of 25th meeting of protection sub-committee. The sub-committee confirmed the minutes of 25th meeting of Protection Sub-committee, held on 12th Feb., 2014 issued vide letter no. NRPC/OPR/107/01/2014 dated 16.04.2014 A.2 Tripping since last PSC PSC decided that members should analyse the grid incidents listed in the agenda and implement remedial actions under intimation to NRPC Secretariat. It was decided to discuss the important incident

a. Tripping of 765/400kV ICT-1& 2 of Bhiwani(PG) on 6th February 2014 at 09:09hrs Event category: GI-2 or GD-1 Loss of load: Not submitted by Haryana Generation Loss: Nil NRLDC informed that at 09:09hrs of 6th February 2014, 765/400kV ICT-1&2 had tripped due to flashover in the Y&B-phase bushing of the ICTs. As per PMU data it was observed that fault was of transient nature and got cleared within time limit of zone-1.

First in B-ph. At 09:09:15.800hrs timely cleared

Second in Y-ph. At 09:09:18.880hrs timely cleared

It was informed by POWERGRID representative that flashover occurred simultaneously in Y-phase bushing of ICT-1 & B-phase bushing of ICT-2. POWERGRID also took up this issue with manufacturer. It was also informed that bushing of ICTs was being replaced with Polymer bushing. POWERGRID was requested to submit a detailed report of the incident within a weeks’ time and status of replacement of bushing with time frame.

b. Multiple element tripping at 400/220kV ICTs Bassi on 11th February 2014 at 09:33hrs Event category: GD-1 Generation loss: Nil Loss of load: 150MW NRLDC informed that at 09:33 hrs of 11th Feb 2014, a fault occurred on 220kV Bassi-Kukas line and at the same time both the 400/220kV ICT’s at Bassi also tripped. As per PMU details it was observed that fault was in Y-phase and persisted for around 600ms. As per NRLDC SCADA Data & SoE:

It is clear both ICTs were overloaded before occurrence of the fault. ICT-2 had tripped at 09:33:13.872hrs & ICT-1 had tripped at 09:33:13.912hrs

Representative of NRLDC posed following issues:

Clearance of fault in~600ms instead of 100ms needs to be looked into. One more ICT at Bassi needs to be expedited because as per SCADA data it was clearly

seen that both the ICTs are fully loaded and in case of tripping of one ICT other would have definitely tripped on over load protection.

Reason as to why tripping of 220kV Bassi-Kukas line was not observed in NRLDC SoE needs to be looked into.

Wiring of Digital Signal of Dausa/Kukas Station needs to looked into. Representative of POWERGRID informed that the Fault was in Bassi-Kukas line. Main-1 relay of distance protection is out of service due to internal card failure. Further due to schematic wiring error in Main-2 relay, line could not trip from Bassi end. Problem with both relays has been rectified. Further both ICTs had tripped on Back-up Over-Current and Earth Fault protection. Representative from Rajasthan informed that he had telephonic conversation with executive of Bassi and it was informed from site that bus fault occurred at 220kV Bassi station but bus bar protection did not operate. Representative of POWERGRID stated that he would confirm the above with the site personal and inform the sub-committee.

S.E.(O0, NRPC stated that this tripping requires more clarity. It was decided that POWERGRID and RVPNL would jointly investigate the incident and submit the analysis report to NRLDC/NRPC within 15days.

c. “Tripping of ±500kV Balia-Bhiwadi Bipole”

i. Multiple element tripping at 400kV Bhiwadi station along with ±500kV Balia-Bhiwadi Bipole on 12th February 2014 at 16:30hrs Event category: GI-2 Generation loss: Nil Loss of load: Nil NRLDC informed that at 16:30hrs of 12th February 2014, ±500kV Balia-Bhiwadi bipole tripped on line fault. As per PMU data, fault was not observed and slight changes in the voltage were captured due to tripping of various lines from 400/220kV Bhiwadi station. Name of the tripping elements are given below:

400kV Bhiwadi-Gurgaon 400kV Bhiwadi-Bassi 400/220kV ICT-1 & 2 at Bhiwadi 220kV Bhiwadi-Bhiwadi ckt 220kV Bhiwadi-Khuskhera ckt 220kV Bhiwadi-Rewari ckt Balia-Bhiwadi Bipole

It was informed by representative of POWERGRID that fault was in both the pole of HVDC and was of transient nature. It is a rare to have transient fault in both the pole at same time. POWERGRID informed that as per there information no 400kV lines have tripped. But as the PMU plots shows otherwise. It was decided that POWERGRID would review the tripping and submit the detailed analysis report to

NRLDC/NRPC within 7days.

ii. Tripping of ±500kV Balia-Bhiwadi Bipole on 2nd April 2014, at 00:28hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil NLDC informed that at 00:28hrs of 2nd April 2014, ±500kV HVDC Balia-Bhiwadi Bipole tripped due to problem in filter bank. It has been informed that HVDC has logic of minimum filter. If connected filter reached below 2 filters, it would send the trip command to the HVDC bipole. On 2nd Apr 2014 as voltage was ~425 kV and on this voltage HVDC has limitation to inhibit the automatic inclusion of filters as per harmonic suppression requirement. At the same time, one filter bank of HVDC tripped and as HVDC bipole was already at minimum filter operation, it resulted into tripping of Bipole. It was also informed that as the power flow of 400kV a.c. line associated with 400kV Bhiwadi station falls below 20MW, the protection scheme sends signal to protecting relays to trip the ±500kV HVDC Balia-Bhiwadi bipole. NRLDC suggested that it should also incorporate power flow of ICT’s at Balia so that unwarranted tripping could be prevented. Elements opened in antecedent condition due to high voltage condition: 400kV Bhiwadi-Neemrana ckt-1 400kV Bhiwadi-Moga ckt-2 400kV Agra-Bhiwadi ckt-1 POWERGRID informed that on 02.04.2014, Bipole was running with power order of 250 MW with minimum filter requirement of 02 filters and prevailing AC Voltage of 426.5KV. Before tripping, 02 sub bank filters were connected (01 sub banks from Filter-1 and 01 sub-bank with Filter-2).One filter from Filter bank-2 tripped on harmonic overload. As per logic, connection of filters is inhibited if the AC Bus Voltage is > 425.2KV. Since, the AC Bus Voltage was >425.2KV, even after tripping of Filter-2, further connection of filters was inhibited and HVDC Bipole remained with the only Sub Filter (Filter-1), which does not fulfill the minimum filter criterion leading to tripping of Bipole. It was also informed by POWERGRID representative that this setting is under discussion and would inform the house after final outcome. It was agreed that POWERGRID would submit the analysis report & settings to NRLDC/NRPC within 7days

iii. Tripping of ±500kV Balia-Bhiwadi Bipole on 17th April 2014, at 13:11hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil It was reported that at 13:11hrs of 17th Apr 2014 ±500kV Balia-Bhiwadi HVDC Bipole tripped on differential protection operation of filter bank in HVDC. Elements opened in antecedent condition due to high voltage condition: 400kV Bhiwadi-Neemrana ckt-1 400kV Bhiwadi-Moga ckt-2 400kV Agra-Bhiwadi ckt-1 400kV Bhiwadi-Kotputli ckt As per PMU data, fault was in Red phase & got cleared within time limit of zone-1. Representative of POWERFRID informed that on 17.04.2014, Bipole was running with power order of

250MW with minimum filter requirement of 02 filters. The prevailing AC Voltage of 428KV. Before tripping, 03 sub bank filters were connected (02 sub banks from Filter-2 and 01 sub-bank with Filter-1). R-Phase string of Filter-2 failed resulted in the operation of differential protection of Filter-2 and therefore, the 02 sub banks of filter -2 got disconnected. As per logic, connection of filters is inhibited if the AC Bus Voltage is > 425.2KV. Since, the AC Bus Voltage was >425.2KV, even after tripping of Filter-2, further connection of filters was inhibited and HVDC Bipole remained with the only Sub Filter (Filter-1), which does not fulfil the minimum filter criterion leading to tripping of Bipole. In this case also, PSC reiterated that power flow on ac lines together with power flow of ICT’s at Balia should be observed for the purpose of tripping bipole on low current. d. Multiple element tripping at 400kV Deepalpur on 14th Feb 2014 at 02:28hrs Event category: GD-1 Generation loss: Nil Loss of load: 150MW NRLDC informed that at 02:28hrs of 14th February 2014, many lines from Deepalpur tripped on over voltage protection operation along with 765kV Agra-Meerut line. Name of the tripping elements are given below:

400kV Abdullapur-Deepalpur ckt 400kV Bawana-Deepalpur ckt 400kV Deepalpur-Kabulpur double ckt 220kV Deepalpur-Barhi ckt 765kV Agra-Meerut ckt

As per PMU data, fault had occurred at 02:28:42.960hrs with maximum dip in Blue-phase voltage. Fault clearing time was ~520ms. It is inferred from PMU data that 765kV Agra-Meerut ckt had tripped at 02:28:39.120hrs. Points requiring more clarity:

Clearance of fault in 520ms instead of 100ms is cause of concern. Wiring of Digital Signal of these lines needs to be looked into. Location of fault needs to be established.

POWERGRID, DTL and HVPNL were requested to submit the report within 15 days e. Multiple element tripping at 400 kV Mainpuri(PG) on 14th February 2014 at 01:08hrs Event category: GI-2 Generation loss: Nil Loss of load: Nil NRLDC informed that at 01:08hrs of 14th February 2014, 400kV Mainpuri-Paricha D/C reportedly tripped on over voltage protection. Name of the tripping elements are given below (as per UP Report & NRLDC SoE):

400kV Mainpuri(PG)-Paricha(UP) ckt 1 400kV Mainpuri(PG)-Paricha(UP) ckt 2 400kV Mainpuri-Fatehpur ckt 2

As per PMU data and SoE:

At 01:08:21.120hrs R-phase to ground fault was observed in PMU data and got cleared within time. It seems from SoE that at this time, 400kV Mainpuri-Paricha ckt1 and 400kV Mainpuri-Fatehpur ckt2 had also tripped.

At 01:08:43.800hrs Y-phase to ground fault was observed in PMU data and got cleared within time. It seems from SoE that 400kV Mainpuri-Paricha ckt2 had tripped.

Points requiring more clarity: Tripping of both 400kV Mainpuri-Fatehpur ckt 2 & Mainpuri-Paricha ckt1 at the same

time needs explanation.

Insufficient information reported to RLDC/RPC. It is a cause of great concern.

Non-auto reclosing of 400kV Mainpuri-Paricha D/C & Mainpuri-Fatehpur ckt2 on transient faults needs to be looked into

Representative of POWERGRID informed that that following are the reason of tripping of lines : Mainpuri Paricha Ckt –1: R-phase to Ground fault took place in Mainpuri Paricha ckt I at 1:07:47.103 hrs with fault current 6.3 KA and distance 28.33 km from Mainpuri end , subsequently line auto reclosed from Mainpuri end but did not auto reclose from Paricha end. Line tripped at 1:07:52.211 Hrs on DT signal received at Mainpuri end from Paricha. Since 5 sec delay is observed on DT signal received, it seems that Over voltage protection is operated at Paricha end which need clarification from UPRVUNL Mainpuri –Fatehpur Ckt-2: REF protection of Line reactor operated at Mainpuri end due to failure of Neutral Grounding Resistance LA at Mainpuri end, DT signal send to Fatehpur and line tripped. Mainpuri-Paricha Ckt-2 - Y-N fault at 1:08:33.517 Hrs took place in Mainpuri paricha ckt II with fault current 2.9 KA and distance 74.42 KM from Mainpuri end. It was also informed that auto-recloser at Paricha end of Mainpuri-Paricha D/C is not working. Report from Paricha TPS is still awaited. No Person from UPRVUNL attended the meeting. PSC recommended that auto recloser problem at Paricha end should be corrected at the earliest. Further, POWERGRID should relook into the time synchronization of DR of Mainpuri end of Mainpuri-Paricha ckt-2. SE(O), NRPC requested UPPTCL to convey to UPRVUNL to attend the meetings in future and also submit the detailed report of the tripping. f. Tripping of Nathpa Jhakri-Nallagarh D/C on 15th Feb, 2014 at 14:23hrs Event category: GI-2 Generation loss: Nil Loss of load: Nil NRLDC informed that at 14:23hrs of 14th February 2014, 400kV Nathpa-Jhakri-Nallagarh D/C tripped on phase to phase fault in Y-B phase. As per Plant report generation in antecedent condition was nil. It has been observed from PMU data that at 14:23:57.240hrs 28kV voltage dip was observed in both yellow and blue phase. It is inferred from PMU data that YB phase to ground fault was observed in

the line. As per designed SPS scheme tripping of any 2 lines from Jhakri resulted into tripping of 2 units at Jhakri & 2units at Karcham Wangtoo. Points requiring more clarity:Jhakri & Karcham may confirm about receiving of SPS signal at their machine at the time of tripping of double ckt because it was not reported to NRLDC. Representative of POWERGRID informed that due to inclement weather & heavy snowfall, snow deposited on both the ckt resulted into fault in both the ckt. Operation of distance protection in both the lines simultaneously is correct operation. No representative from SJVNL attended the meeting. It was requested that report of the events may be submitted within a week’s time to NRPC sect. with a copy to NRLDC. g. Tripping of 400kV Mainpuri(PG)-Fatehpur(PG) D/C on 16th February 2014 at 06:01hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil NRLDC informed that at 06:00:54hrs of 16th Feb 2014, 400kV Fatehpur-Mainpuri D/C tripped on operation of REF (Restricted earth fault) Protection of Reactor. As per PMU data and SoE: At 06:00:54.240hrs, maximum dip was fault in Yellow phase and got cleared within time. As per NRLDC SoE at 06:00:54.360hrs 400kV Mainpuri-Fatehpur D/C tripped from Fatehpur end. POWERGRID representative informed about the reasons for tripping as under: Mainpuri-Fatehpur ckt II: Line tripped on REF protection of line reactor operated due to failure of NGR LA at Mainpuri end. DT signal received at Fatehpur end and line tripped. Mainpuri-Fatehpur ckt I: line tripped on false DT signal received at Fatehpur end however Mainpuri has not sent any DT signal. PLCC testing along with end to end testing performed but nothing found abnormal. PLCC panel was tested again & put under observation. PSC advised POWERGRID to see the issue of time synchronization of DR at Mainpuri(PG) end and also put the PLCC Panel under observation.

h. Multiple element tripping at 400kV Chamera1 on 21st February 2014 at 19:32hrs

Event category: GD-1 Generation loss: 350MW Loss of load: Nil NRLDC informed that at 19:32hrs of 21st February 2014, During closing of unit, unit CB of B-phase got stuck and it resulted into operation of LBB for Bus-II and all the elements connected to Bus-II at 400kV Chamera-1 tripped. Detailed report from NHPC has been received. This report might be used by the other entities for their reference. Extract of the report is reproduced below:

i. Multiple Element tripping at Koteshwar HPS:

i. Multiple Element tripping at Koteshwar HPS on 23rd February 2014 at 05:40hrs

Event category: GD-1 Generation loss: 90MW Loss of load: Nil NRLDC informed that at 05:40hrs of 23rd Feb 2014, 400kV Koteshwar-Koteshwar(Pooling) ckt 1& 2 reportedly tripped due to operation of over voltage protection. One running unit at Koteshwar HEP also tripped due to tripping of both the outgoing lines. As per PMU data, there was not enough high voltage to initiate TOV stage-1. But as per DR, high voltage was observed at Koteshwar HEP point. Max voltage at Meerut PMU was ~431kV & as per DR voltage was ~441kV, such a large difference in the voltage at nearby node of the line needs to be looked into as Voltage as Meerut PMU was well below 440kV but at Koteshwar HPS it was around~440kV. As per NRLDC SoE: All the elements tripped from Koteshwar PG end first (05:41:00.351hrs) and after

60ms of this tripping (05:41:00.426hrs) line tripped from THDC end.

Unit-1 CB at Koteshwar(THDC) end tripped after 2 second of tripping of lines.

As per DR printout of THDC & POWERGRID: As per DR details that Koteshwar(THDC)-Koteshwar(PG) ckt-1&2 tripped at

05:40:58hrs from THDC end & DT received to remote end.

DT received at Koteshwar(PG) end at 05:41:00.331hrs.

Points requiring more clarity:

Reason of non-matching of DR & SoE timing needs to be looked into.

Delayed receipt of DT at Koteshwar(PG) end needs to be looked into.

Time synchronization of DR at Koteshwar(PG) Koteshwar (THDC) for ckt 1 & 2 needs to be looked into.

Over voltage setting at Koteshwar(THDC) end & Koteshwar(PG) needs to be reviewed by the respective utility. Because it was observed in many incidents, these lines tripped from THDC end on over voltage protection operation.

POWERGRID representative informed that Koteshwar(PG)-Koteshwar(THDC) lines tripped many times on over voltage protection and voltage measured at POWERGRID end is ~108%. There may be either time & voltage grading problem of over voltage protection or CVT measurement problem at Koteshwar(THDC) end. It was also informed that Koteshwar(PG) end DR is time synchronized. Representative from Koteshwar(THDC) didn’t attend the meeting. PSC was concerned about the frequent tripping of these ckt’s. It was decided that POWERGRID and THDC should meet to analyse the trippings and inform NRPC/NRLDC about the findings within 15days. Further there is a need to expedite installation of reactor at Koteshwar end.

ii. Multiple element tripping at 400kV Meerut (PG) on 28th February 2014, at 02:48hrs Event category: GI-2 Generation loss: Nil Loss of load: Nil NRLDC informed that at 02:48hrs of 28th February 2014, 765kV Agra-Merrut line tripped on over voltage, 400kV Koteshwar(PG)-Koteshwar(THDC) D/C and 400kV Dadri-G. Noida also tripped at the same time on over voltage protection. 400kV Ballabhgarh-Nawada was already open due to high voltage since 01:58hrs. As per PMU data, NRLDC SoE & DR Printout: As per PMU data phase to phase (R-Y phase) fault occurred nearby Meerut at 02:47:14.280hrs & 02:47:15.400hrs.

Later on at 02:47:16.400hrs there was 4kV rise in Meerut end voltage, as per SoE at the same time 765kV Agra-Meerut line CB of Meerut end closed.

At 02:47:18.440hrs the same CB tripped from Meerut end also.

As per SoE at 02:47:21.273hrs 400kV Dadri-G. Noida tripped from Dadri end.

As per DR it seems 400kV Koteshwar(THDC)-Koteshwar(PG) tripped on over voltage protection at ~02:47:20.720hrs

Representative of POWERGRID informed that R-N fault took place in 765kV Agra-Merrut line at 2:47:14:313 hrs. Line was Auto reclosed through Main CB after dead time of 1 sec but all three poles tripped due to recurring fault. At Agra end, Both Main & Tie CB tripped. However, at Merrut end, Tie CB could not trip due to missing of blocking signal wire, therefore line was auto-reclosed at Merrut end after dead time of 2 secs (considering priority scheme). Thereafter Over-voltage protection operated at Agra end & direct trip received at Merrut end. 400kV D/C Koteshwar(PG)- Koteshwar(HPS) line tripped on Direct trip received at Koteshwar(PG) end. It was also informed that problem of tie CB at Meerut(PG) end has been resolved.

Following points require more clarity: It seems that reset ratio in 400kV Koteshwar(THDC)-Koteshwar(PG) & 400kV Dadri-G. Noida

may be on lower side (95% or better). Concerned entities may review the reset ratio of the over voltage protection.

It seems from NRLDC PMU data that voltage at Meerut was ~432kV after tripping of 765kV Agra-Meerut line. Therefore, reset ratio of over voltage protection may be an issue and may be looked into.

DR timing of Koteshwar(THDC) end needs to be looked into.

PSC was concerned about the frequent tripping of these ckt’s. It was decided that POWERGRID & THDC would hold a meeting and update the RPC/RLDC about the findings within 15days.

j. Tripping of 220kV Wagoora-Zainakote D/C on 26th February 2014 at 20:19hrs Event category: GD-1 Generation Loss: Nil Load Loss: 400MW NRLDC informed that at 20:19hrs, 220kV Wagoora-Zainakote ckt-1&2 tripped on R-phase to ground fault. As per PMU data also it was inferred that fault was in Red phase and got cleared within prescribed time. Tripping of both the ckt simultaneously needs to be looked into. Issue could not be discussed as no representative from PDD J&K attended the meeting. PSS advises PDD, J&K to submit a detailed report. k. Multiple element tripping at 400kV Singrauli:

i. Multiple Element tripping at 400kV Singrauli on 27th February 2014, at 07:59hrs

Event category: GD-1 Generation loss: Nil Loss of load: 180 MW (UP may confirm about load loss) Representative of NRLDC informed that at 07:59 hrs of 27th February 2014, as reported, “3-phase fault observed in 400kV Singrauli-Vindhyachal ckt2 due to broken OPGW wire of the line. 400kV Anpara-Singrauli line also tripped from Anpara end reportedly due to mal-operation of relay”. As per PMU data, max dip observed in the voltage of Yellow phase. Fault got clear within time limit of zone-1. In SoE, status of CB of Vindhyachal end of 400kV Singrauli-Vindhyachal ckt2, Bus coupler at Vindhyachal station & Anpara end of 400kV Anpara-Singrauli was available. Other end status was not observed. Wiring of Digital Signal of other end of above lines needs to be looked into. As per NTPC report, 400kV Singrauli-Vindhyachal Ckt-2 tripped from Singrauli end in zone-1 as fault was in OPGW ground wire and all 3-phase tripped in zone-1 from Singrauli end. 400kV Singrauli-Anpara line didn’t trip from Singrauli end. It was observed that NTPC is reporting the event at the time of meeting but as per IEGC clause 5.2 (r,) reports should be submitted to RPC/RLDC within 24hrs of the incident. POWERGRID informed that the fault was in Singrauli-Vindhyachal Ckt-2. The relay at Anapara end had seen the fault in Zone-2 but instantaneously issued trip command in SOTF trip. Upon investigation it was found that, CB close status is not available to the relay. If CB close status is

not available, after the SOTF delay time (110 secs as per setting), relay will automatically enable SOTF function in the relay. This problem has been rectified. PSC advised POWERGRID to look into the SOTF time delay setting of 110 second. UPPTCL/NTPC was requested to submit the report within a week’s time.

ii. Multiple element tripping at 400kV Singrauli TPS on 5th May 2014 at 17:23 hrs

Event category: GI-2 Generation loss: Nil Loss of load: Not submitted by UPPTCL NRLDC informed that at 17:23 hrs of 5th May 2014, 400kV Singrauli-Vindhyachal & Singrauli-Rihand ckt tripped from Singrauli end. As per PMU data it seems fault persisted in the system for ~80ms & fault was in Red phase. Preliminary Report, Detailed Report along with DR/EL from NTPC/POWERGRID were awaited. NTPC/POWERGRID were requested to elaborate the incident and submit the analysis report to NRLDC/NRPC. Representative of POWERGRID informed that at 17:24:22.983 Hrs, CT of Bus reactor bay had a blas. Subsequently, Bus reactor tripped on Differential protection. However, no other tripping and code transfer had taken place at Vindhyachal end. As per NTPC report it seems that 400kV Singrauli-Vindhyachal ckt tripped from Singrauli end in Zone-1. But tripping of all 3-phases in zone-1 needs to be looked into by NTPC although fault was in single-phase. Reason of tripping of both 400kV Singrauli-Vindhyachal & Singrauli-Rihand was not clear. It was observed in many events, details from NTPC were received within prescribed time. PSC requested NTPC to submit the report within a week’s time. l. Tripping of 400kV Bassi-Heerapura D/C on 3rd March 2014 at 03:25 hrs Event category: GI-2 Generation Loss: Nil Loss of load: Nil As reported, on 3rd Mar 2014 at 03:25hrs, 400kV Bassi-Heerapura ckt-1&2 tripped on over voltage protection. As per PMU details antecedent voltage at 400kV Agra was ~433kV. Representative of POWERGRID informed that over voltage protection operated at Heerapura end & direct trip was received at Bassi end. As per DR details it was observed that Tie CB of 400kV Bassi(PG) end of 400kV Bassi-Heerapura line was already under open condition. POWERGRID was requested to furnish reason of the same. Representative of POWERGRID agreed to do so within 15 days. Rajasthan informed that Over-Voltage setting at Heerapura is 110 % with a time delay of 03 sec and 05 sec. for ckt.1 & 2 respectively. It was decided to change the setting to 110 % with a time delay of 05 sec and 06 sec. PSC advised RVPNL to inform NRPC/NRLDC after carrying out the change.

m. Multiple element tripping at 220kV Ropar TPS on 05th March 2014, at 00:45hrs Event category: GD-1 Generation loss: 385MW Loss of load: 155MW As reported on 05th March 2014 at 00:45hrs, flash over in generator transformer occurred resulted into tripping of 2 running unit at 220kV Ropar TPS. It is inferred from PMU data that fault got cleared in 960ms instead of 160ms at 220kV level. PSC advised PSPCL to look into delayed clearance of fault. Further, preliminary Report, detailed Report along with DRs/EL from Punjab was awaited. PSTCL/PSPCL was requested to submit the detailed report within a weeks’ time to NRPC sect. with a copy to NRLDC n. Multiple element tripping at 400/220kV Daultabad station:

i. Multiple element tripping at 400/220kV Daultabad on 06th March 2014 at 07:29hrs Event category: GD-1 Generation loss: Nil Loss of load: 200 MW It has reported that at 07:29hrs of 6th march 2014 “Blue phase CT of 400kV Daultabad-Gurgaon ckt2 blasted. After blasting of CT, some part of CT touched to R-phase CT of adjacent ckt 400kV Daultabad-Jhajjar ckt1 and it resulted into leakage in Red phase CT of 400kV Daultabad-Jhajjar ckt1. It was reported that Blue pole CB of 400kV Daultabad-Jhajjar ckt-1 also failed at the same time. Bus Bar Protection operated for Bus-1 of Daultabad station. All 400kV elements tripped either on Bus Bar protection operation or tripped from remote end”. Inference from PMU data, NRLDC SoE & SCADA Data: As per PMU data there were two incidents of fault. First one is in Blue phase and second time fault was in Red phase. Same is corroborated with the telephonic information.

Fault clearing time: first incident- 240ms; Second incident- 640ms.

It seems from PMU data that some ckt’s tripped from remote end due to delayed clearance of fault from Daultabad station.

MVAR flow in SCADA data has been shown in 400kV Daultabad-Gurgaon ckt1 i.e. this ckt only tripped from Daultabad end.

Slight oscillation in frequency was observed for 11second

Detailed report from Haryana had been received and extract of the report is mentioned below.

List of Events : 1. At 07:25:36.927hrs of 06.03.2014, 400kV “B” Phase Current Transformer (AREVA MAKE) of 400kV Daulatabad – Sector-72 (PGCIL) Gurgaon Ckt-2 (Bus-1 Bay-413) bursted & caught fire thus causing a buszone fault. 2. Pick-up of Zone-4 Protection (DPS) recorded in DPR Relays (Siemens make) of 400kV Daulatabad – Sector-72 (PGCIL) Gurgaon Ckt-2 (Bay-413) but no tripping event recorded as Zone-4 (Rev. Zone time is 1s).

3. At 07:25:39.017hrs, 400kV CB of “B” phase of 400kV Daulatabad – Jharli Ckt-1 (Bay-410, adjucent of bay-413) also bursted/damaged & caused a busbar zone fault.”R” phase CT of Bay-413 also leaked due to breakage of porcelene caused by splinters of bursted CT of Bay-410. 4. An event of operation of Busbar Protection (Make Siemens Model- ) observed in MCU Busbar protection relay thus inititated the commands to trip all CBs connected to 400kV Bus-1 for both 07:25:36.927 & 07:25:39.017hrs. 5. Record confirmed the tripping of CBs of Bay-416 (Bus-1 CB of 400kV Daulatabad - Sector-72 (PGCIL) Ckt-1) as well as its tie CB (Bay 417). The “96” Busbar protection relays of both CBs found operated in 1st instance. The actual tripping time of both CBs can’t be included in the scope of investigation as both bay BCU’s GPS Time Sync was not OK. The DT Command was initiated to trip the 400kV CB at 400kV Sector-72 (PGCIL end) , Gurgaon as per PLCC Counters :

Channel Reading on 05.03.2014

Reading on 06.03.2014 after fault (2 Busbar fault events)

Ch-1 02 28 Ch-2 02 30

DT command not received at 400kV Sector-72 (as confirmed by 400kV Sector-72 PGCIL) and the controlling CB remained charged at PGCIL end. 6. Similarly the tripping of CBs of Bay-413 (Bus-1 CB of 400kV Daulatabad - Sector-72 (PGCIL) Ckt-2) as well as its tie CB (Bay 414). The “96” Busbar protection relays of both CBs found operated in 1st instance. The actual tripping time of both CBs can’t be included in the scope of investigation as the BCU of Bay-414 was defective & Bay-413 BCU’s was not GPS Time Sync.

The DT Command was initiated to trip the 400kV CB at 400kV Sector-72 (PGCIL end) , Gurgaon as per PLCC Counters :

Channel Reading on 05.03.2014

Reading on 06.03.2014 after fault (2 Busbar fault events)

Ch-1 20 57 Ch-2 22 59 As confirmed by 400kV PGCIL Sector-72 , the 400kV CB controlling 400kV Sector-72 – Daulatabad Ckt-2 tripped at Sector-72 end by DT-Receive.

7. The tripping of CBs of Bay-410 (Bus-1 CB of 400kV Daulatabad – APCPL Jharli Ckt-1) as well as its tie CB (Bay 411). The “96” Busbar protection relays of both CBs found operated in 1st instance. The actual tripping time of both CBs can’t be included in the scope of investigation as the BCU of Bay-410 was defective & Bay-411 BCU’s was not GPS Time Sync. The DT Command was initiated to trip the 400kV CB at 400kV Sector-72 (PGCIL end) , Gurgaon as per PLCC Counters :

Channel Reading on 05.03.2014

Reading on 06.03.2014 after fault (2 Busbar fault events)

Ch-1 548 787 Ch-2 550 789 The counters of Ch-1 remained at 02 , the reasons for which needs to be checked by CC wing.

8. “96” (Aux. trip relay of BB Prot) of Bay-407 (400kV Daulatabad-Jharli Ckt-2) didn’t found operated and both bus CB as well as Tie CBs remained “ON” during incident. Status of DT Counters:

Channel Reading on 05.03.2014

Reading on 06.03.2014 after fault (2 Busbar fault events)

Ch-1 399 399 Ch-2 246 246 No incident of increase in DT counter recorded. However, later the PLCC terminal was found defective during further testing by CC staff.

9. “96” (Aux. trip relay of BB Prot) of Bay-405 (400kV Daulatabad - Dhanonda Ckt-2 didn’t found operated and both bus CB as well as Tie CBs remained “ON” during incident. Status of DT Counters:

Channel Reading on 05.03.2014

Reading on 06.03.2014 after fault (2 Busbar fault events)

Ch-1 82 86 Ch-2 74 78 The DT sent is connected to BU (87.1) relay directly & is not dependent on

input from “96” relay thus DT command was initiated by 87.1 (BU) relay to trip at 400kV Dhanonda end. It is reported from 400kV Dhanonda that no DT command is received & their CB tripped with Z2 protection after 350ms of incidence.

10. “96” (Aux. trip relay of BB Prot) of Bay-402 (400kV Daulatabad-Dhanonda Ckt-2) didn’t found operated and Tie CB (Bay-403) remained “ON” during incident. C of Bay-402 was already switched off since long due to shut down. Status of DT Counters:

Channel Reading on 05.03.2014

Reading on 06.03.2014 after fault (2 Busbar fault events)

Ch-1 40 40 Ch-2 31 31 The CC communication between 400kV Daulatabad-Dhanonda Ckt-1 was

found out of order & probably caused non-increment of DT counter as well as DT-S command

‘.. It is reported from 400kV Dhanonda that no DT command is received & their CB tripped with Z2 protection after 350ms of incidence.

11. The fault of damage of CT/CB probably also feed from 400/220kV ICTs (3 No’s) & thus caused tripping of 220kV feeding sources (220kV Daulatabad-Manesar Ckt-1 & Ckt-2 , 220kV Daulatabad-Nunamajra Ckt-1 & Ckt-2) with E/F relay at 220kV Daulatabad end.

12. The Earth Faults relays of above said circuits were made non-directional recently due to interrupted events of PT missing & thus causing blocking of operation of E/F relay (if made Directional THROUGH VOLTAGE SOURCE).

Preliminary Diagnosis: 1. MCU-1(Main-1) of Siemens make Numerical Busbar Protection operated as

detailed below: a) Damage of 400kV “B” phase CT of 400kV Daulatabad-Sector-72 Ckt-2:

07:25:36.927 Power System Fault 83 ON Fault Event 83 ON Trip Bus 1 L3 ON 0ms Trnsf Trp BU@03 ON 233ms b) Damage of 400kV “B” phase CB (CB-410) of 400kV Daulatabad-Jharli Ckt-1:

07:25:39.017 Power System Fault 84 ON Fault Event 84 ON Trip Bus 1 L1 ON 377ms Trip Bus 1 L3 ON 377ms Trnsf Trp BU@02 ON 592ms (Bay-410) Trnsf Trp BU@03 ON 592ms (Bay-413) 2. From the BU (Busbar Unit-87.1) relay fault data records, it is found that all

the 87.1 relays of bay 416,413,410,407,405 & 402 received a communication from MCU-1 caused tripping of Aux. Busbar Protection Relays (96) of Bay-416/417, 413/414, 410/411, 407 but the Aux. Protection Relay (96) of Bay 405 & 402 not operated. The circuit from 87.1 relay to 96 relay checked for both 405 & 402 bays found OK. Matter discussed with M/s Siemens & after due checking of D.R., M/s Siemens requested for “Process Data” records of every 87.1 relay (all bays). Cause of non-operation of (96) relays by 87.1 relay is yet unknown & to be diagnosed by M/s Siemens & will be reported shortly.

3. The Busbar Protection Stability as well as Inter-tripping for both Bus-1& 2 was tested on 24.05.2013 & 26.05.2013. The operation of tripping of all CBs connected to both buses was assured & found OK during testing. DT send signal was also assured to output from PLCC links for various lines/circuits.

4. “B” Phase Areva make CT (damaged) of 400kV Daulatabad-Sector-72 Ckt-2 was tested for Tan-delta on 12.04.2013, IRV/Ratio test/secondary Winding Resistance on 12.03.2013 found OK.

5. The carrier inter-tripping of 400kV Daulatabad-Sector-72 Ckt-1 & Ckt-2 is recently tested on 25.02.2014 for all signals by CC Staff found OK.

6. The carrier inter-tripping of 400kV Daulatabad-Dhanonda Ckt-2 is tested on 27.01.2013 & 28.01.2013 for all signals by CC Staff found OK.

7. On 06.04.2013, CC staff again tested the protection inter-tripping between 400kV Daulatabad-Dhanonda Ckt-1 & Ckt-2 & reported that PLCC terminal for Ckt-1 is switched off from Dhanonda due to internal defect.

8. On 31.12.2013, CC staff tested the protection inter-tripping between 400kV Daulatabad-Jharli Ckt-1 & Ckt-2 & reported OK.

9. It is highly recommended to investigate the matter of non-operation of (96) relays by M/s Siemens independently. It is also recommended that the before commissioning of replacement 400kV CT of 400kV Daulatabad-Sector-72 bay, the stability as well as inter-trip (with actual DT trip) be conducted by arranging

10. M/s Siemens relay engineers at site in the presence of M&P/TS to avoid such incidents in future.

11. The investigation of damaged CT as well as CB to be done independently by manufacturer for its damage to trace out any manufacturing defect & proper cause of damage.

12. No provision of GPS Time Sync is done at 220kV Daulatabad so no proper fault diagnosis be done to coordinate various events of 400kV & 220kV Substations for a time specific fault.

Points need to be discussed: Delayed clearance of fault in case of operation of Bus Bar protection needs to be

reviewed.

Operation of 400kV Daultabad-Dhanonda ckt-1 without tie CB needs to be looked into.

Time synchronization problem at Daultabad station needs to be checked & rectified.

HVPNL informed that the delayed clearance of fault was due to failure of 2

Nos Back Up (BU ) relays causing non-sending of DT at remote end as well as

non-initiation of tripping command to CBs at Daulatabad ends. Both BUs have

been reconfigured. The MCU-2 (Busbar Protection Main-2) is still to be

replaced by M/s Siemens for which matter is under discussion with M/s

Siemens.

Further, issue of operation of 400kV Daultabad-Dhanonda ckt-1 without tie CB is

under progress with M/s Siemens. The tie circut was out due to defective

400kV CT , the work will be completed till mid of June 2014.

Also the problem of Time synchronization at Daultabad station is under process

with M/s Siemens.

It was informed by Haryana that 400kV Gurgaon-Daultabad line had tripped from

Gurgaon end only in zone-2 & Jhajjar-Daultabad D/C also tripped from Jhajjar end

only.

There is some confusion in the understanding of the setting of both ends. PSC

decided that APCPL & HVPNL should hold a joint meeting within 15 days & sort out

the problem at their end.

ii. Multiple element tripping at 400/220kV Daultabad Station on 01st May

2014 at 16:30hrs

Event category: GD-1 Generation loss: Nil Loss of load: 450 MW NRLDC informed that at 16:30hrs of 1st May 2014, there was a blast in B-phase CT at 220kV Nuna-Mazra station. At the same time 400/220kV 315MVA all 3 ICTs along with 400kV Daultabad-Gurgaon ckt2 & 400kV Daultabad-Jhajjar ckt1 tripped. As per PMU data it seems that there was fault in R-phase that got clear but almost at the same moment another fault in B-phase observed. Total Fault clearance time was ~1000ms. Delayed clearance of fault is clear violation of CEA grid standard. Representative of HVPNL informed that on 01.05.2014 at 16:29:24 Hrs , the “R” Phase

220kV Current Transformer of 220kV Daulatabad-NunaMajra Ckt-1 bursted with heavy

sound and splash of Oil & splinters of porcelain. Along with the damage of CT, 220kV

Nunamajra Ckt-1 tripped off with Zone-1 Distance Protection (Main-1) within 19ms as per

DPS event log (Attached). Main-2 distance protection also confirms Zone-1 tripping after

39ms. After an auto-recloser at 238ms, the CB comes under AR Lockout mode & isolated

the faulty portion from 220kV Bus at 220kV Daulatabad. Simultaneously , the “B” phase

jumper of 220kV Daulatabad-Nunamajra CKt-2 snapped out , hanged & touch with tower

at Tower Location #4 (4th tower from substation) caused another B/G fault. Both DPR

(Main-1 & Main-2) detected a PSB fault & blocked operation of relay till 152ms as per

event log.Main-1 confirms AR Lockout @533ms & Main-2 @737ms. The E/F (Directional

Backup) protection didn’t operate with no reason. The operation of relay was recently

tested by M&P team on 11.02.2014 found OK. The 220kV fault was fed by the 3No’s

ICTs operated in parallel to same bus and caused tripping of all ICTs on E/F (220kV

Incomers) @503ms, 683ms & 699ms.

As the GPS synchronization is not operated on 400kV substation & not installed on

220kV substation, the fault analysis up to minute level couldn’t be done. The HV side CBs

(Main+Tie) of all ICTs tripped along with 220kV Incomers due to inter-tripping. No relay

observed on HV side of all ICTs. No 400kV Line affected/tripped during incident. The fault

was also feed from 220kV Manesar & Badshahpur so caused tripping with backup

protection at both substations.

Remedial Measures Adopted by Haryana:

1. Lowering of TMS settings of 220kV OG feeders from 0.19 to 0.15. 2. Provision of Numerical O/C+E/F (With Highset) on all 220kV Outgoing feeders for

better analysis & fine settings. As discussed with SE/TS, Gurgaon, 4No’s spare O/C+E/F (ER Make Numerical Relays) are being spared from 220kV sector-72 Gurgaon and will be erected on following feeders within 2 days. 220kV Daulatabad-Nunamajra-1 220kV Daulatabad-Nunamajra-2 220kV Daulatabad-Manesar-1 220kV Daulatabad-Manesar-2

3. Taking up the matter of non-operation of CSC101 relay with nearby fault & causing relay blocking on PSB. Being same length, settings of DPS relays (Main-1 CSC101, Main-2 CSC101) of 220kV Daulatabad-Nunamajra CKt-1 & 2 were same but the DPS scheme of CKt-1 operated well & DPS scheme of CKt-2 didn’t operate properly. (All 4 No’s DPS relays of Nunamajra Ckt-1 & 2 (Main-1 & 2) were tested by M&P team on 12.03.2014 by PONOVO test kit & found OK. The settings of relays are being sent to ER for further analysis.

PSC advised HVPNL to further clarify following points, in a fresh report:

As per setting provided by Haryana, ICT’s at Daultabad should have tripped in 1000ms as fault current was 4.8kA.

Tripping of ICT at various durations (ICT-1 in 550ms; ICT-2&3 in 760ms) needs to be looked into.

The E/F (Directional Backup) protection didn’t operate. It needs to be looked into.

Wiring of Digital data needs to be looked into. The failure of E/F (Directional Backup) protection

Representative of HVPNL agreed to submit the report within one month.

o. Multiple element tripping at 220kV Salal HEP on 9th March 2014 at 13:25hrs

Event category: GD-1 Generation loss: 100MW Loss of load: Nil Representative of NRLDC informed that in antecedent condition, 220kV Salal-Jammu D/C was under outage & 220kV Bus 2 at 220kV Salal station was under shutdown. At 13:25hrs of 13th Mar 2014, there was problem in excitation system of the unit of Salal HEP, which resulted into tripping of unit CB but it failed to open properly and resulted into

LBB protection operation at 220kV Salal HEP. Name of the tripped elements are given below: 1. 220kV Unit #4 at Salal Station 2. 220kV Salal-Kishenpur all 4 ckts As per PMU & NRLDC SoE Data: Fault clearing time ~240ms (at 13:24:33.080hrs). Later on after 2.8second fault was

again observed in Red phase. Fault clearing time ~440ms (at 13:24:35.800hrs)

It was seen from SoE that all the connected elements at Salal station tripped at ~13:24:33hrs.

Later on at ~13:24:36hrs 400kV Kishenpur-New Wanpoh ckt1 also tripped on R-N fault.

Points need to be answered: It seems from SoE that 220kV Kishenpur-Salal ckt 2 tripped before tripping of unit CB.

Reason of the same needs to be looked into.

DR is not time synchronized at 220kV Salal station.

Tripping of 400kV Kishenpur-New Wanpoh ckt1 was not reported and same needs to be looked into.

Tripping time of 220kV lines shown into SoE is 13:24:33.620hrs but as per PMU data at 13:24:33.320hrs fault got cleared. Reason of the same needs to be explained.

Detailed Report & DR/EL have been received from NHPC but still awaited from J&K. Representative of NHPC informed that fault in unit-4 excitation system was analysed, Rotor over voltage protection was found faulty and the same was replaced. No representative from PDD J&K attended the meeting. It was requested that report of the events along with answers of the points raised by RPC may be submitted by NHPC/ J&K within a week’s time to NRPC sect. with a copy to NRLDC. p. Multiple element tripping at 400kV Bareilly(PG) station:

i. Multiple element tripping at 400kV Bareilly(PG) Station on 18th March 2014 at 11:59hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil As reported, at 11:59 hrs of 18th March 2014, “400kV Bareilly(PG)-Bareilly(UP) ckt2 tripped on phase to phase fault from Bareilly(PG) & Bareilly(UP) end. 400kV Bareilly(PG)-Bareilly(UP) ckt1 tripped from Bareilly(UP) end. 400kV Bareilly(PG)-Rosa ckt tripped on over voltage from Rosa end. 400kV Bareilly-Meerut ckt 2 tripped from Bareilly(PG) end in zone-1 & Meerut end in zone-2, line auto reclosed and finally tripped.” As per PMU data: At 11:59:09.000hrs Fault clearing time = ~200ms. Fault was in Y-phase.

At 11:59:24.680hrs Fault clearing time= ~480ms. Fault was phase to phase & Red & Blue phase

As per DR details: 400kV Meerut(PG)-Bareilly(PG) ckt2 tripped from “Meerut(PG) end”: Zone-2 picked up

for Red & Blue phase & “Bareilly(PG) end”: Zone-1R picked up for Red & Blue phase and seen in reverse zone.

400kV Bareilly(UP)-Bareilly(PG) ckt1 tripped from Bareilly(UP) end at 11:59.08hrs

400kV Bareilly (PG)-Rosa ckt tripped on over voltage protection at 11:59:30.310hrs from Bareilly(PG) end.

As per the POWERGRID ffollowing lines tripped at Bareilly Sub Station: 1. Bareilly(PG)-Bareilly(UP)-2 – Form Both ends 2. Bareilly(PG)-Bareilly (UP) – 1 – From Bareilly (UP) end only 3. Bareilly(PG)-Moradabad(UP) – 1 – From Bareilly end only 4. Bareilly(PG)-Moradabad(UP) – 2 – From Bareilly end only 5. Bareilly –Roza – Tripped on over voltage protection 6. Bareilly-Merrut-2 - A/R operated at Bareilly end while Tripped form Merrut end.

REL 670 relay installed as Main-1 relay while 7SA522 relay installed as Main-2 at Bareilly(PG) end. The line-wise tripping details are as follows: Bareilly (PG)-Bareilly (UP)-2 (Line Length – 14.3kM) – a. Bareilly(PG) end: Tripped from both ends - At 11:59:09:024 Auto re-closure operated

on Y-N Fault at both end. REL 670 (Main-1) –FLR – 14.3kM (100%), Zone-2 Trip 7SA522 (Main-2) –FLR – 13.2kM (92.4%), Zone-1 Trip At 11:59:24:663, fault occurred again in R-B phase which caused outage of line from both ends REL 670 (Main-1) –FLR – 14.3kM (99.8%), Zone-2 Trip due to non-receipt of carrier from remote end 7SA522 (Main-2) –FLR – 13.9kM (97.2%), Zone-2 Trip due to non-receipt of carrier form remote end. Note: Out of 14.3kM, only 9Km from Bareilly(PG) end belongs to POWERGRID, rest is maintained by POWERLINK. As per FLR, fault was in POWERLINK portion. Bareilly(UP) end: C.P.-Main 1-DIST. PROTN. OPTD. R.P.-Main 1-Trip Relay, R, Y & B phase, O/V Relay

RXEG-21 R-phase, A/R relay RXMH2 A/R unsuccessful, A/R optd.

Main 2-R,Y & B-phase, Z1, Aux Relay- Start A/R, Gen Trip, Block A/R, C/S

Bareilly(PG)-Moradabad(UP)–1(Line Length–93kM) – a. Bareilly(PG) end : Tripped from Bareilly end only – At 11:59:24:681, 7SA522 relay

issued trip command in Zone-2 after 352 msecs in R-N Fault. As per impedance locus of 7SA522 relay, Fault seen in R-N loop was in Zone-2 in Forward direction (Which was pick-up & Drop off 3 times in time span of 350msecs). Please note that fault loop in R-B phase was in reverse direction.

Moradabad(UP) end details are not provided by UP. Bareilly(PG)-Moradabad(UP)–2(Line Length–93kM) – Tripped from Bareilly end only – At 11:59:24:680, 7SA522 relay issued trip command in Zone-2 after 352 msecs in R-N Fault. As per impedance locus of 7SA522 relay, Fault seen in R-N loop was in Zone-2 in Forward direction. Please note that fault loop in R-B phase was in reverse direction. Bareilly(PG)-Merrut–2(Line Length–245.785kM) – A/R operated from Bareilly end & Tripped form Merrut end

Bareilly end: At 11:59:24:700, 7SA522 relay issued trip command in Zone-1 after 205 msecs in R-N Fault & auto re-closure operated after dead time. As per impedance locus of 7SA522 relay, Fault seen in R-N loop was in Zone-1 in Forward direction As fault seen by 7SA522 relay (Main-2) was in Zone-2, permissive carried was send to remote end (Merrut end) Merrut end: 7SA522 relay installed as Main-1 relay while REL670 relay installed as Main-2 at Merrut(PG) end. At 11:59:24:663, Both REL670 & 7SA522 relay started in Zone-2 in R-B phase loop. Upon Receipt of carrier from Remote end (Bareilly) from Main-2 Relay (7SA522 Relay), the Main-2 relay at Merrut end i..e REL670 issue trip command /(carrier aided trip) Bareilly (PG)-Bareilly (UP)-1 (Line Length – 14.3kM) – Tripped from Bareilly(UP) end only – Line tripped from Bareilly(UP) end only. a. Bareilly(UP) end: C.P.-Main 1- DIST. PROTN. OPTD

R.P.- R, Y & B phase, Z2 trip, A,B,C, Dist. Trip, Z2 For both 400kV Bareill(UP)-Bareilly(PG) line Main-1 relay is REL-531 & Main2 relay is MICOM

Bareilly (PG)-Roza (Line Length – 123kM) – Line tripped on overvoltage protection (Stage-1) As per UP report, efforts were made for the time synchronization of relay of both Main1 & Main2 of Bareilly(UP)-Bareilly(PG) D/C but it could not be configured due to non-availability of port in these relay. They have informed that these relays are maintained by POWERGRID. Erratic behavior of 400kV Bareilly(PG) end of Moradbad-Bareilly(PG) line needs to be reviewed by POWERGRID & same needs to be corrected. Over voltage setting at Roza end needs to be reviewed by UP. Time synchronization problem at Bareilly(UP) end to be corrected by Bareilly(UP) either through POWERGRID or in-house.

ii. Multiple element tripping at 400kV Bareilly(PG) Station on 28th March 2014 at

14:54hrs Event category: GI-2 Generation loss: Nil Loss of load: Nil As reported, at 14:54hrs of 28th Mar 2014, “R-B phase to ground fault observed in 400kV Bareilly(PG)-Meerut ckt 2, distance was ~20km from Bareilly(PG) end. 400kV Bareilly(PG)-Rosa tripped on overvoltage with per phase voltage reaching ~253kV” As per PMU & NRLDC SoE data: Fault clearing time~80ms. Fault occurring time: 14:54:44.960hrs.

Fault was R-B-phase to ground fault.

Fault was timely cleared by opening of both ends breaker of 400kV Bareilly(PG)-Meerut ckt 2.

It seems after 5 sec of opening of Bareilly-Meerut ckt2, overvoltage protection operated and resulted into opening of tie CB of 400kV Bareilly(PG)-Rosa ckt

POWERGRID reported that in antecedent condition Bus-2 at Bareilly(PG) end was under shut-down and that’s why main CB of Rosa line shown in open condition in DR at Bareilly(PG) end. As Roza ckt is in the same dia of Bareilly-Meerut ckt2 i.e. at the time of tripping of Bareilly-Meerut ckt2 both main & tie CB of this ckt tripped and as tie CB is common for both Meerut ckt-2 & Roza ckt. It resulted into automatic tripping of Roza ckt from Bareilly(PG) end. Roza end breaker may be tripped after 5second on over voltage protection operation. All the tripping was in manner. q. Multiple Element tripping at 400/220kV Gorakhpur(UP) Station on 20th March

2014 at 00:52hrs

Event category: GD-1 Generation loss: Nil Loss of load: 100 MW As per UP Detailed Report: Antecedent Connectivity (As per UP Report):

At 00:52 hrs on 20.03.2014, at 400KV Gorakhpur S/S, the following lines/elements tripped simultaneously. The normalisation time of the lines/elements is mentioned below:

SI. No.

Name of line/element Date & time of synchronization

Remarks

1. 400 KV Gorakhpur-Gorakhpur (PG) ckt-I 20.03.2014  02:12 hrs 2. 400 KV Gorakhpur-Gorakhpur (PG)ckt-II 20.03.2014  02:11 hrs 3. 240 MVA ICT at 400 KV S/S Gorakhpur 20.03.2014  02:16 hrs 4. 400 KV Gorakhpur-Azamgarh line 20.03.2014  02:35 hrs

5. 220 KV Gorakhpur-Gorakhpur (PG) line 20.03.2014  02:48 hrs 6. 220 KV Gorakhpur (PG)-Basti line 26.03.2014  13:31 hrs R-phase conductor

broken,S/D 7. 220 KV Tanda-Basti line 20.03.2014  04:32 hrs 8. 160 MVA ICT- I at 220 KV S/S Basti 21.03.2014  00:17 hrs 132 KV side B-phase LA

and CT damaged, S/D 9. 132 Basti-Dumariaganj line 21.03.2014  17:05 hrs Y-phase PT damaged

Extract of UP Detailed Report: It has been reported by UPPTCL site that at 00:52hrs of 20.03.2014, at 220 kV Basti

S/S, Y-phase PT got damaged and R-phase conductor of 132 kV Basti-Dumariaganj bay snapped. Due to above fault, distance protection relay operated but circuit breaker at Basti S/S did not trip.

Simultaneously at 220 kV Basti S/S, B-phase LA and CT of 132 kV side of 160 MVA ICT-I got damaged. Due to above fault, protection relay operated but circuit breaker at Basti S/S did not trip.

At 400 KV Gorakhpur S/S, 400 KV Azamgarh line was on TBC

Simultaneously R-phase conductor of 220 KV Gorakhpur PG-Basti line broke/snapped, which resulted in tripping of circuit breaker at 220 kV Tanda TPS and tripping of 220 kV Gorakhpur (PG) - Gorakhpur (UP) at both the ends. Simultaneously, LBB and Bus Bar Protection operated at 400 kV Gorakhpur UP S/S which resulted in tripping of all the lines/elements resulting in complete supply failure at 400 kV S/S Gorakhpur.

After deliberations, PSC advised following actions: At 220 KV Basti S/S, non-tripping of circuit breaker of 132 KV Basti-Dumariaganj line

be checked/investigated and remedial action be taken (Action UPPTCL).

At 220 KV Basti S/S non-tripping of HV side breaker of 220/132 KV, 160 MVA ICT-I be checked/investigated and remedial action be taken (Action UPPTCL).

At 400 KV Gorakhpur S/S, the reason of operation of LBB/Bus Bar protection be checked/investigated and remedial action be taken (Action UPPTCL).

It seems from flag details that TBC backup over current protection have sensitive setting resulted into operation and tripping at 400kV Gorakhpur UP. Same needs to relooked. As similar type of problem is already observed in case of tripping of Anpara TPS. (Action: UPPTCL)

Charging of 400kV Gorakhpur-Azamgarh line through transfer CB for long time is not a healthy practice . (Action: UPPTCL)

Availability of backup of D.C. supply at 220kV Basti station needs to be checked. (Action: UPPTCL)

Bus Bar Protection at Gorakhpur UP station needs to be reviewed. . (Action: UPPTCL)

Protection at 220kV Basti station needs to be thoroughly checked & tested . (Action: UPPTCL)

Detailed report from UP has been received but DR/EL is still awaited. In many incidents it was mentioned in detailed report that “Prints out of disturbance recorder & Event recorder are not available”.

UP was requested to submit the information about the problematic area & what action UP is being taken in this regard.

r. Multiple element tripping at 400kV Sarnath(UP) Station: i. Multiple element tripping at 400kV Sarnath(UP) on 30th Mar 2014 at

12:35hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil At 12:38hrs on 30.03.2014, at 400KV Sarnath S/S, the following lines/elements tripped simultaneously resulting in complete supply failure at 400 KV Sarnath S/S. The normalisation time of the lines/elements is mentioned below: “It has been reported by UPPTCL site that at 12:36hrs on 30.03.2014, B-phase conductor of 400 KV Sarnath-Azamgarh line snapped and CB tripped at 400 KV Azamgarh S/S. But at Sarnath S/S the line distance protection relays (SIPROTEC & RAZFE) did not operate. At Sarnath S/S, 400 KV Bus Bar protection did not operate. This resulted in tripping of all the lines from remote ends and supply failed at 400 kV Sarnath S/S.” As per PMU Details & UP reports: As reported conductor of phase-B snapped in 400kV Azamgarh-Sarnath line but PMU

shows maximum voltage dip in both R & B-phase.

As per UP reports during the fault all lines connected to Sarnath tripped at other end but connected at Sarnath S/S. it shows distance protection failure (Siprotec & Razfe did not sense the fault at Sarnath end).

After 2 minutes i.e. at 12:38:28.096 CB of Anpara-Sarnath L5 line tripped at Sarnath S/S. while the others CB’s not operated, it shows abnormal behavior of Siprotec relay, it needs to be relooked.

As per UP reports at 12:48:16.786 hrs, 400kV Sasaram-Sarnath D/C tried to synchronize resulting over voltage was observed at Sarnath S/S and CB of Sarnath-Anpara line at Sarnath end tripped in zone-1 instead of zone-2. (For L-3 Zone-1 & Zone-2 both pickup so line may be tripped in zone-1) In L-5, Zone-1 pickup but fault locator is showing 99%). Similarly Azamgarh-Sarnath tripped in zone-1(Zone-1 & Zone-2 both pickup so line may be tripped in zone-1)

It seems that 400kV Anpara-Sarnath ckt1&2 tripped at 12:35:47hrs from Anpara end. 400kV Allahabad-Sarnath ckt tripped from Allahabad end at 12:35:48hrs.

SI. NO. 

Name of element  Date & time of normalization 

Remarks 

1.  240 MVA, ICT at Sarnath  30.03.2014  13:20   

2.  315 MVA, ICT at Sarnath  30.03.2014  13:20   

3.  400 KV Sarnath‐Azamgarh  ‐  ‐  B/D. B‐Phase line conductor broken 

4.  400 KV Sarnath‐Anpara (L‐3)  30.03.2014  13:53   

5.  400 KV Sarnath‐Anpara (L‐5)  30.03.2014  13:55   

6.  400 KV Sarnath‐Allahabad (PG)  30.03.2014  13:41   

7.  400 KV Sarnath‐Sasaram(PG)  30.03.2014  17:25   

400kV Azamgarh-Sarnath ckt tripped from Azamgarh end at 12:35:58hrs (F-11 is breaker between Azamgarh & ICT-2). Other end breaker tripping not observed in SoE. Wiring of Digital signal of Sarnath end of 400kV Sarnath-Azamgarh ckt needs to be looked into.

400kV Sarnath-Anpara ckt1 tripped from Sarnath end at 12:38:28hrs.

400kV Sarnath-Sasaram & Anpara ckt2 tripped from Sarnath end at 12:48:16hrs

Extract of the report is given below:

PSC suggested following remedial Actions-

At 400 KV Sarnath S/S, line distance protection relays Main-I & Main-II are to be

checked and tested and remedial action be taken (Action: UPPTCL).

At 400 KV Sarnath S/S, Bus Bar Protection to be checked and remedial action be taken (Action: UPPTCL).

Carrier inter tripping scheme of 400 KV Saranth-Azamgarh line be checked and remedial action be taken (Action: UPPTCL).

Tripping of Anpara-Sarnath line in Zone-1 needs to be reviewed. (Action:UPPTCL).

Bus Bar Protection to be installed at Sarnath. (Action:UPPTCL)

Auto reclosing to be made functional in Anpara-Sarnath line needs to be looked up. (Action:UPPTCL)

Coordination of time setting of relays on both ends of Anpara-Sarnath line. (Action:UPPTCL)

Wiring of Digital signal of Sarnath end of 400kV Sarnath-Azamgarh ckt needs to looked into. (Action:UPPTCL)

UPPTCL was requested to submit the reply of the above mentioned points within 15 days.

ii. Multiple element tripping at 400kV Sarnath(UP) on 14th April 2014 at 09:02

hrs

Event category: GD-1 Generation loss: Nil Loss of load: 422 MW It has been reported by UPPTCL site that at 09:02 hrs on 14.04.2014, “a B-phase to ground fault took place on 400 kV Sarnath-Azamgarh line. At 400 kV S/S Azamgarh circuit breakers tripped but CB did not trip at 400 kV S/S Sarnath, as the line distance protection relays (SIPROTEC & RAZFE) did not operate. At Sarnath S/S, 400 kV Bus Bar protection is defective/out of service. This resulted in tripping of all the lines from remote ends except 400 kV Sarnath-Anpara (L-5) which tripped at Sarnath S/S. Thus complete supply failed at 400 kV Sarnath S/S”. Name of the tripping elements and restoration time is given below: S.

NO.

Name of element/line Date & time of normalization

Remarks

1. 400 KV Sarnath-Anpara (L-5) 14.04.2014 09:28 CB tripped at Sarnath S/S 2. 400 KV Anpara-Mau (L-6) 14.04.2014 10:02 3. 400 KV Sarnath-Anpara (L-3) 14.04.2014 10:07 4. 400 KV Sarnath-Allahabad (PG) 14.04.2014 10:10 5. 400 KV Sarnath-Sasaram 14.04.2014 10:26 6. 400 KV Sarnath-Azamgarh 14.04.2014 13:45 Blue phase to earth line fault 7. 220 KV Sarnath-Ghazipur 14.04.2014 09:45 8. 220 KV Sarnath-Gajokhar 14.04.2014 09:46 9. 220 KV Sarnath-Sahupuri 14.04.2014 09:47 As per PMU data & NRLDC SCADA Data: PMU voltage plots from Balia Station indicates occurrence of B (Blue) phase to earth

fault.

Fault clearing time is observed as appr 2000ms. It is a delayed fault clearing.

Just after the tripping of lines from Sarnath, power flow in 765 kV Anpara-Unnao line has increased by about 500MW. Also power flow in 400 kV Singrauli-Allahbad D/C line has increased after the tripping.

Connectivity diagram at the time of tripping is given below:

It is clear from UP’s report that at 400 kV Sarnath S/S, line distance protection relay (Azamgarh Bay) Main-I (RAZFE) has been replaced by SIPROTEC relay. Also, Main-II (SIPROTEC) relay has been checked/ tested.

PSC suggested following remedial Actions: At 400 kV Sarnath S/S, Bus Bar Protection be rectified and put back in service at the

earliest. (Action UPPTCL).

Carrier inter tripping scheme of 400 kV Sarnath-Azamgarh line be checked for correct operation under fault conditions (Action UPPTCL).

400 kV Sarnath-Anpara (L-5) line tripped at Sarnath S/S in the reverse direction. Line distance protection relay is to be checked and remedial action be taken (Action UPPTCL).

400 kV Anpara-Mau line tripped at Mau S/S for a 400 kV fault at Sarnath S/S. This needs further investigation (Action UPPTCL).

Non-tripping of 400kV Azamgarh-Sarnath ckt from Sarnath end needs to be looked into. (Action UPPTCL)

Carrier inter tripping scheme of 400 kV Sarnath-Azamgarh line needs to be reviewed. (Action UPPTCL)

Tripping of 400kV Anpara-Mau line from Mau end on fault in 400kV Azamgarh-Sarnath line needs to be looked into. (Action UPPTCL)

It is worthy to mention here that there is no Bus Bar protection scheme available at Sarnath S/S which is a requirement as per Grid standards for all substations of 220 kV and above level. (Action UPPTCL)

Non-tripping of 400 kV Sarnath-Anpara (L-5) from Anpara end needs to be checked that’s why this line later on tripped in reverse zone protection operation at Sarnath S/S. (Action UPPTCL)

What was the status of ICTs at the time of tripping? ICTs also tripped or remained in operation? If ICT didn’t trip than reason of non-tripping of ICT’s needs to be relooked because fault persisted in the system for ~2000ms. (Action UPPTCL)

UPPTCL was requested to submit the reply of the above mentioned point’s within 15 days time

iii. Multiple element tripping at 400/220kV Sarnath(UP) on 5th May 2014 at

09:03 hrs

Event category: GD-1 Generation loss: Nil Loss of load: 420 MW “It has been reported by UP that at 09:03hrs on 05.05.2014, while doing the maintenance work (on 220kV Sahupuri Bay) maintenance staff provided the T&P to other staff by tugging and throwing PVC rope which was deflected and intruded in the electrical clearance range of live part of 220kV transfer Bus tandem isolator of Sahupuri bay (The transfer Bus was in service since 04.05.2014 due to air leakage in 160 MVA 220/132kV ICT-II ABCB breaker). This resulted in immediate tripping of 400/220kV, 315MVA ICT-I on

Back up Earth fault and 240MVA ICT-II on overload causing 220kV & 132kV Bus dead.” As per PMU data, fault persisted in the system for ~320ms & fault was in Yellow phase. As per NRLDC SoE data, Bus became open after 7.7second of fault time. Preliminary Report & Detailed Report has been received from UP. PSC recommended following actions: Over Flux alarm on 220kV side of 315MVA ICT-I & 400kV side of 240MVA ICT-II

needs to be relooked. (Action: UPPTCL)

Bus Bar protection scheme should be installed/made functional at Sarnath S/S which is a requirement as per Grid standards for all substations of 220 kV and above level . (Action: UPPTCL)

UPPTCL was requested to submit action plan for above mentioned point’s within 15 days’ time

s. Multiple element tripping at 400kV Azamgarh: i. Multiple element tripping at 400kV Azamgarh on 31st March 2014 at 14:36

hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil It has been reported that at 14:36hrs of 31st March 2014, “B-Phase to earth fault took place on 400 KV Azamgarh-Sultanpur line. The fault was isolated by tripping of circuit breaker CB 91 & CB 96 at Azamgarh (ring bus) Substation and corresponding CB at Sultanpur Sub station. Simultaneously, at Azamgarh Substation, CB 95 of Gorakhpur line also tripped. The tripping of Gorakhpur line was due to mal-operation of newly commissioned Siemens make SIPROTEC (M1 protection) and the matter is being taken up with M/S Siemens. 400kV Azamgarh Substation has ring bus system”. Connectivity diagram is given below:

As per PMU & NRLDC SoE Data:

Fault clearing time: 500ms. Delayed clearance of fault is a cause of concern. Fault was in Blue phase

It seems from SoE that breaker at Azamgarh end tripped at ~14:36:31hrs, it may be due to time synchronization problem of SoE because as per PMU data fault didn’t persist for 19second.

Detailed Analysis report has been received from UP. PSC recommended following remedial actions: At 400 KV Azamgarh S/S, tripping of CB-95(Gorakhpur bay) be checked and attended

(Action UPPTCL).

Carrier Inter-tripping Scheme of 400 KV Azamgarh-Sultanpur line be checked and attended (Action UPPTCL)

Tripping of Azamgarh-Sultanpur line from Sultanpur end in Zone-1 but fault got clear

after 500ms of tripping of Sultanpur end breaker, it means tripping of azamgarh end breaker in zone-2. Non-working of inter tripping scheme needs to be relooked. (Action: UPPTCL)

Tripping of 400kV Azamgarh-Gorakhpur line needs to be looked into. (Action: UPPTCL)

SoE timing at azamgarh end needs to be relooked. (Action: UPPTCL)

Tripping of 400kV Azamgarh-Gorakhpur line was not observed in NRLDC SoE. Reason of the same also needs to be checked at site. (Action: UPPTCL)

It was reported that DR/EL printouts are not available, kindly send the .dat file so that it could analyse through software available at NRLDC. (Action: UPPTCL)

UPPTCL was requested to submit the reply of the above mentioned point’s within a week’s time

ii. Multiple element tripping at 400/220kV Azamgarh on 13th April 2014 at 12:32hrs

Event category: GD-1 Generation loss: Nil Loss of load: 200 MW As reported at 12:32hrs of 13th Apr 2014, LBB protection operated for 220kV Azamgarh-Sarnath line. Name of the tripping elements are given below: 400kV Azamgarh-Sultanpur 400kV Azamgarh-Gorakhpur Azamgarh 315MVA ICT-1 Azamgarh 315MVA ICT-2 220kV Azamgarh-Sarnath line

PSCC recommended following action: As per PMU details it seems fault was in Yellow-phase and got clear in Zone-1 timing 80ms. In that case, operation of LBB needs to be relooked. If LBB protection operated for 220kV Azamgarh-Sarnath line then 400kV Azamgarh-Sultanpur & Azamgarh-Gorakhpur

ckts could not have tripped. (Action:UPPTCL) UPPTCL was requested to submit the report within 15 days to NRPC sect. with a copy to NRLDC.

t. Multiple element tripping at 400/220kV Muradnagar Station on 1st April 2014 at

04:06hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil As reported, at 04:06hrs of 1sr April 2014, "Y-phase to ground fault occurred in 400kV Agra-Muradnagar line. Fault was in zone-1 from Agra end & zone-2 from Muradnagar end. 400kV Agra-Muradnagar line tripped in zone-1 from Agra end but Muradnagar end CB failed to open in zone-2 resulted into LBB protection operation at 400kV Muradnagar station and all elements connected to that bus tripped”. Name of the tripping elements are given below along with restoration time:

Connectivity Diagram (as reported):

As per PMU data, SoE & UP report:

At 04:06:40.120hrs, 400kV Agra-Muradnagar line tripped on Y-phase to ground fault. It seems from SoE & Flag details that this line tripped from Agra end in Zone-1 and it didn’t tripped from Muradnagar end, at the same time as fault was in Zone-2 from Muradnagar end. It seems from SoE that PLCC for 400kV Agra-Muradnagar line is not working otherwise it must be tripped on receipt of carrier from remote end.

Ideally after 500ms, at 04:06:40.680hrs this line should be tripped from Muradnagar end but it seems from SoE that Breaker of Muradnagar end of 400kV Agra-Muradnagar line didn’t open and it resulted into operation of LBB after 200ms, at ~04:06:01.880hrs.

LBB operation on Bus-A resulted into tripping of all the elements connected on that Bus and 400kV elements Panki line, Muzzaffanagar line, 400/220kV ICT-2 tripped almost at similar time

At 04:06:40.912hrs 400kV Muzaffarnagar-Muradnagar line breaker also opened from Muradabad end. It seems that LBB is sending the signal to remote end, if it is so then 400kV Panki end and Agra end must be tripped at 04:06:40.912hrs.

Agra end of 400kV Agra-Muradnagar line auto reclosed at 04:06:41.040 but it was unsuccessful attempt of auto-reclosing of line as from PMU data, it seems that fault was again observed and Agra end breaker finally tripped at 04:06:41.160.

As per frequency plot, after LBB operation load loss didn’t occurred. Although ICT-2 tripped during the event but due to LBB operation Tie breaker CB-95 opened. It resulted into separation of faulty section and prevents ICT-1 and ICT-3 to trip.

As 400kV Muradnagar-Muzaffarnagar line tripped, load of Muzaffarnagar met from Meerut so current of 400kV meerut-muzaffarnagar ckt rises and same is clearly observed in Meerut PMU data of current.

Preliminary report and detailed report has been received from UP.

PSC recommended following actions: At 400 KV Muradnagar S/S, the complete line distance protection scheme (Main-I &

Main-II) along with Switchgear of Agra line be checked and remedial action be taken (Action: UPPTCL).

At 400 KV Muradnagar S/S the LBB/Bus Bar Protection Scheme be checked (Action: UPPTCL).

PLCC for 400kV Agra-Muradnagar line needs to be relooked. (Action: UPPTCL)

Non opening of CB of 400kV Agra-Muradnagar line at Muradnagar end needs to be reviewed. (Action: UPPTCL)

LBB scheme at 400kV Muradnagar station is to be made operational. (Action: UPPTCL)

Reason of non-receipt of flag at Muzaffarnagar ckt & ICT needs to be relooked. (Action:UPPTCL)

UPPTCL was requested to submit the reply of the above mentioned point’s within 15 days.

u. Multiple element tripping at 220kV IA Hisar (HVPNL) sub-station on 6th April

2014, at 17:43hrs

Event category: GD-1 Generation loss: Nil Loss of load: 75 MW Representative of NRPDC informed that as per telephonic conversation it was informed that at 17:43hrs of 6th Apr 2014, “there was fault in 220/132kV 50MVA ICT at Hissar(IA) and blue-phase CT bursted. As bus bar protection at 220kV Hissar(IA) was not available that why all the elements at 220kV Hissar IA tripped.” Name of the tripping elements are given below: 220kV Hisar(IA)-Hisar(BBMB) D/C 220kV Hisar(IA)-Hisar(PG) D/C 220kV Hisar(IA)-Narwana ckt 220kV Hisar(IA)-Masudpur D/C

As per PMU data B-phase to ground fault occurred at 17:43:16.360hrs with maximum dip of 85kV. HVPNL was requested to clarity following: 1. Fault clearance time was ~460ms. Delayed clearance of fault needs to be looked into.

2. Non-availability of Bus Bar Protection at 220kV station level is clear violation of CEA

Technical Standard for Construction of Electrical Plants and Electric Lines

As per HVPNL Report:

In the answer of above points HVPNL reported that (1) All the lines tripped from remote end in zone-II i.e. after 350ms time delay due to non-

availability of the bus bar protection. Matter under consideration of the Nigam. (2) The existing bus bar protection scheme (HBB make, Radha type) is very old/static and

the wiring work etc. is incomplete; new numerical scheme to be provided. (3) All relays installed on 22/132kV 50MVA ICT-3 are electromechanical in nature and no

extra DR/EL are installed on the panel.

Flag details of the tripping is given below:

HVPNL was requested to submit a timeline of completion of corrective measures to NRPC sect. with a copy to NRLDC. v. Multiple element tripping at 220kV Udhampur sub-station on 07th April 2014 at

05:09hrs

Event category: GI-1 Generation loss: Nil Loss of load: Nil It has been reported that at 05:09hrs of 07th March 2014, 220kV Udhampur-Kishenpur D/C & Udhampur-Sarna ckt tripped on phase to ground fault. It is inferred from PMU data that fault was in R&B phase & timely got clear. Following points requires more clarity in understanding the tripping: 1) Faulted line & sequence of event needs to be established 2) Tripping of multiple elements on same fault needs to be relooked. POWERGRID representative informed that Fault occurred due to lightening in that region at that particular time. Tower top patrolling was done and Flashover marks and shattering of 1-2 discs were found. PD measurement planned and being carried out shortly. No representative from J&K attended the meeting. It was requested from POWERGRID/ J&K that detailed report along with DR/EL of the events may be submitted within a week’s time to NRPC sect. with a copy to NRLDC.

w. Complete Blackout at 220kV Harduaganj Station on 9th April 2014 at 05:41hrs

Event category: GD-1 Generation loss: 407 MW Loss of load: 450 MW

It has been reported by UPPTCL site that at 05:40hrs on 09.04.2014 “at Harduaganj switchyard, Y-phase jumper between CT and Bus of 220 KV Harduaganj- Hathras (Radial) line broke. Bus Bar Protection has not been installed at Harduaganj TPS. The fault was isolated by tripping of all the 220 KV lines at Harduaganj TPS from remote ends in Zone – II. Generating unit nos 8 & 9 which were on bar, tripped on over current protection. Thus complete 220 KV supply failed at 220 KV Harduaganj TPS”. Name of the tripping elements along with normalization time is tabulated below: S.

NO. Name of element/Generator Date & time of

normalization Remarks

1. Harduaganj Gen. Unit No. 8 10.04.2014 00:03 2. Harduaganj Gen. Unit No. 9 09.04.2014 17:35 3. 220 KV Harduaganj-Hathras line 09.04.2014 13:22 Y-phase jumper broken at

HDJ switchyard 4. 220 KV Harduaganj-Mainpuri line 09.04.2014 06:49 5. 220 KV Harduaganj-Atrauli line 09.04.2014 07:07 6. 220 KV Harduaganj-Khurja-I line 09.04.2014 07:07 7. 220 KV Harduaganj-Etah line 09.04.2014 07:10 8. 220 KV Harduaganj-Khurja-II line 09.04.2014 08:20 Connectivity Diagram is given below:

Flag details received from UP:

As per PMU data & SoE: Fault Clearance time: 440ms

Max dip in voltage observed in R-phase voltage.

Definite loss of load occurred because rise in frequency shown in PMU plot.

220kV Harduaganj-Khurja D/C tripped at 05:41:10.383hrs well before occurrence of fault.

PSC recommended following remedial Actions by UPRVUNL/UPPTCL:- At 220 KV Harduaganj TPS, Bus Bar Protection be installed and commissioned at the

earliest.

Protection at Harduaganj station needs to be thoroughly checked because complete 220kV Harduaganj station blackout occurred 4 times in last 1year.

Delay in clearance of fault needs to be looked into.

Tripping of 220kV Khurja- Harduaganj D/C before fault needs to be looked into.

Max dip in R-phase shown in PMU although it was reported that fault was in Y-phase. It needs to be reviewed.

Reason of tripping of unit-8&9 at Harduaganj station needs to be established.

Protection at Harduaganj station needs to be thoroughly checked because complete 220kV Harduaganj station blackout occurred 4times in almost last 1year. Details of the tripping are tabulated below.

S.NO.

Outage Name of Elements

that Event

Generation/Loa

Category as per

Outcome Recommendation

Date Time (in Hrs)

tripped/manually opened

d Loss CEA Grid

Standards

1 10.04.13

13:09 hrs

220kV NAPS-Khurja1 220kV NAPS-Khurja2 220kV NAPS-Atrauli 220kV NAPS-Sambhal 220kV NAPS-Simbholi 220kV Meerut-Simbholi 220 kV Harduaganj-Khurja-D/C 220 kV Harduaganj-Atraulli-S/C 220 kV Harduaganj-Mainpuri-D/C

Delayed clearance of fault and other protection misoperation at UPPTCL substations around 220 kV Narora and Harduaganj.

Gen. Loss=40 MW

GD-1 Delayed clearance of fault and other protection misoperation at UPPTCL substations around 220 kV Narora and Harduaganj

2 04.06.13

12:32

hours

Complete 220kV Harduaganj Generating station includes: 220kV Harduaganj-Etah ckt 220kV Harduaganj-Atrauli ckt 220kV Harduaganj-Hathras ckt 220kV Harduaganj-Mainpuri ckt 220kV Harduaganj-Khurja ckt-1 220kV Harduaganj-Khurja ckt-2 220/132kV, 100MVA ICT-1&2 Unit 8&9 of 250MW

As per U.P. preliminary report fault was in 220kV Harduaganj-Etah line. Multiple element tripped due to delayed clearance of fault.

Generation Loss-390MWLoad Loss- Still awaited from UP

GD-1

As reported fault occurred in 220kV Harduaganj- Etah line. It is inferred from PMU that fault got cleared in 1760ms. Reason for complete outage of Harduaganj station needs to be examined by UP. Delayed Clearance of fault also need to be investigated.

U.P. may elaborate the incident and submit the analysis report to NRLDC/NRPC and also apprise the members about the remedial measures being taken to avoid such incident in future.

3 11.07.13

02:08 hours

220kV Harduaganj-Etah ckt 220kV Harduaganj-Atrauli ckt 220kV Harduaganj-Hathras ckt 220kV Harduaganj-Mainpuri ckt 220kV Harduaganj-Khurja ckt-1 &2 220/132kV, 100MVA ICT-1&2 132kV Harduaganj-Sarsol ckt-1&2 220kV NAPP-Khurja ckt-1&2 220kV NAPP-Atrauli ckt 220kV Khurja-Sikandrabad Unit 8&9 of 250MW

As reported Y-phase isolator of 220kV Harduaganj-Khurja ckt2 connected to Main Bus-2 damaged and its conductor fell down. Due to absence of Bus Bar Protection all the lines tripped from remote end.

Loss of Generation~410MW Loss of Load~ 600 MW

GD-1

DRs/EL along with analysis report is yet to be received from U.P. Not Applicable

4 09.04.14

05:41 hours

Harduaganj Gen. Unit No. 8

Harduaganj Gen. Unit No. 9

220 KV Harduaganj-Hathras line

220 KV Harduaganj-Mainpuri line

220 KV Harduaganj-Atrauli line

220 KV Harduaganj-Khurja-I & II line

220 KV Harduaganj-Etah line

It was informed by Harduaganj TPS, that R-phase jumper of C-Isolator of 220kV Hathras line broke at Harduaganj TPS which resulted in tripping of all the 220 KV lines and generators leading to 220 KV supply failure at Harduaganj TPS

Gen Loss~407MW Load Loss~450MW

GD-1

Not discussed yet Not Applicable

No Person from UPRVUNL attended the meeting. PSC requested UPPTCL to convey to UPRVUNL that their nominee should attend the meeting. UPPTCL/ UPRVUNL were requested to submit the reply of the above mentioned point’s within 15 days.

x. Multiple element tripping at 400kV G. Noida on 12th April 2014 at 06:36

hrs

Event category: GD-1 Generation loss: Nil Loss of load: 420 MW Representative of NRLDC informed that at 06:36hrs of 12th Apr 2014, Bus Bar Protection operated at 400kV G. Noida station. 400kV G. Noida-Dadri & G. Noida-Nawada ckt tripped. As per PMU data, fault persisted in the system for ~480ms & fault was in Yellow phase. As per NRLDC SoE, Bus became open after 7.7second of fault time. Power flow diagram as per SCADA data is mentioned below:

HVPNL informed that 400kV Nawada-G. Noida tripped on over current protection. PSC recommended following remedial actions:

Bus Bar protection operation at G. Noida station needs to be relooked. Exact location of fault needs to be established. (Action: UPPTCL)

HVPNL may also inform about the status of other Bus at 400kV Nawada station, which was earlier unavailable due to problem of Bus CT. (Action: HVPNL)

Over current protection needs to be disabled in all 400kV lines as per NRPC protection philosophy. (Action: HVPNL)

UPPTCL and HVPNL were requested to submit the detailed report within 15 days. y. Multiple element tripping nearby Rajpura & Observance of oscillation in Rajpura

unit:

i. Heavy Oscillation observed in Punjab area of NR System on 16th Apr &

18th Apr 2014 at 06:40 & 15:43hrs

Event category: GD-1 Generation loss: 700MW (16th Apr 2014) & 200MW backing down (18th Apr 2014) Loss of load: 420MW As reported at 06:40hrs of 16th Apr 2014- “it is observed that with the damage of B- Phase CT & Breaker Limb at 220 KV s/s Nabha resulted into tripping 220kV Balwan-Nabha ckt and 220kV Nabha-Faggan Majra Ckt-1&2 in Zone-2. However during this incident all the other Ckts i.e. 220 KV Balwan-Dhuri ckt 1&2, 220KV Balwan-Sunam Ckt 1& 2, 400KV Balwan-Rajpura ckt 1&2, 400KV Balwan-Talwandi circuit were in healthy condition during and after the incidence. Further, as reported by NPL, due to large fluctuation in generation of NPL Unit, the unit was switched Off by NPL operator.” Antecedent scenario as per Punjab preliminary information is given below:

As per PMU Data (16th Apr 2014): Oscillations were observed in the system for 2 minutes.

Oscillations were in envelope manner, as in the case of swing.

It seems that fault got clear in Zone-2 timing of 350ms.

Oscillation may be either due to some problem in governor of the unit or MW redistribution may result into overloading of any 220kV element.

As reported at 15:43hrs of 18th Apr 2014, “as per initial finding it is observed that there was some problem at Rajpura machine and generation was reduced by 200MW at Rajpura station.” As per PMU Data(18th Apr 2014): Oscillations were observed in the system for ~2minutes.

Oscillations were in envelope manner, as in the case of swing.

It seems from PMU phase voltages that there was not any fault in the system at the same time.

Oscillation may be either due to some problem in governor of the unit or overloading of any 220kV element

Extract of NPL letter is given below:

Preliminary Report from Punjab has been received but Detailed Report along with DR/EL and exact sequence of event from Punjab is still awaited. As per CEA (Technical standards for connectivity to the Grid) Regulation 2006 & IEGC every generating unit of 100MW and above should have their PSS properly tuned. Representative of Punjab informed that PSS has been tuned recently by the OEM.

ii. Multiple element tripping at 220kV Nabha station on 29th Apr 2014 at 12:31

Event category: GD-1 Generation loss: 660MW Loss of load: Nil As per Punjab Report, “It has been observed that with the damage of R- Phase CT & Breaker Limb at 220 kV s/s Nabha resulted into tripping 220kV Balwan-Nabha ckt and 220kV Nabha-Faggan Majra(220kV Patiala) Ckt-1 in Zone-3 along with 220/66 kV T/F. However during this incident all the other Ckts i.e. 220kV Balwan(400/220kV Dhuri)-Dhuri

ckt 1&2, 220kV Balwan-Sunam Ckt 1& 2, 400kV Balwan-Rajpura ckt 1&2, 400kV Balwan-Talwandi circuit were in healthy condition. At 00.30hrs NPL Unit-1 of 700MW running on Ex-bus generation of 660MW generation was tripped by NPL due to fluctuation in generation.” Antecedent scenario as per Punjab preliminary information is given below:

Sr.No Name of the

Transmission Line

Tripping Time

Restoration

Time Indication

Cause of Tripping

Remarks

1 220KV Nabha-Dhuri(400KV)

00:25 Hrs -

DPR main-1 ABC phase at Nabha end 21.2 relay 21 km, DPR Master 86.2 at Bhalwan end

220 KV Side, Red phase CT & Breaker limb damaged

2 220KV Nabha-Faggan Majra

Ckt-1 00:25 Hrs

01:52 Hrs

Main-1, Z-3, 42.69 km

-

Tripped from Faggan Majra

end

3 100 MVA, 220/66

KV T/F Nabha 00:25 Hrs 01:52 Hrs Master trip.

-

As per PMU Data & DR printouts: It seems that fault got clear in 240ms. Delayed Clearance of fault needs to be looked

into.

220kV Dhuri-Nabha ckt tripped on operation of distance protection.

220kV Dhuri-Nabha ckt tripped at 12:31:12:960hrs

Oscillation was not observed in the system.

Punjab reported that fault was in R-phase CT of 220kV Nabha end of 220kV Nabha-Dhuri ckt. This fault was cleared at 400kV Dhuri end within 185ms (Carrier inter-tripping) i.e. within time. But this resulted in tripping of 400kV Rajpura-Dhuri ckt-1&2 from NPL, Rajpura end on under voltage. So NPL was advised to disable the under-voltage setting. PSC recommended following: Tripping of unit at Rajpura needs to be relooked because oscillation was not observed

in the system and fault also got clear in 240ms. (Action: NPL)

Non-tripping of 220kV Nabha-Patiala ckt from nabha end needs to be reviewed. (Action: NPL)

Non-operation of bus bar protection at Nabha station needs to be looked into. (Action: NPL)

DR/ EL at 220kV Dhuri station to be time synchronized. (Action:PSTCL)

RPC requested Punjab to submit the status of corrective measures & bus bar protection at 220kV Nabha Station.

z. Multiple tripping of 400kV lines in Rajasthan & Rajwest Generation on 17th Apr

2014, 23:26hrs

Event category: GD-1 Generation loss: 717 MW Loss of load: Nil Representative of NLDC informed that “At around 23:26hrs due to heavy storm, post insulator of 400 kV Bus-B at jodhpur damaged caused Bus Bar protection operation for Bus-B and resulting into tripping of all 400kV emanating lines from Jodhpur except-Merta ckt2. 400kV Rajwest-Jodhpur D/C tripped on DT received from Jodhpur end. 400kV Rajwest-Barmer and 400/220kV ICT at Rajwest tripped on over loading. All six machines (135X6 MW) of Rajwest available on 400 kV side tripped due to evacuation problem. It was reported that Jodhpur load was feeding through 220kV Pali & Boranda ie load loss didn’t occur in the system.” Sequence of Event as per data available: At23:26:36.585 - Tie Breaker Jodhpur line 1 open. At23:26:36.586 - Jodhpur line 2 breaker open. At23:26:36.587 - Jodhpur line 1 breaker open. At23:26:36.590 - Tie Breaker Jodhpur line 2 open. At23:26:49.506 - ICT 220 kV breaker trip. At23:26:49.512 - ICT 400 kV tie breaker trip. At23:26:49.514 - ICT 400 kV main Circuit Breaker Trips. At23:27:12.063 - Unit # 5 Generator Circuit Breaker bus 1 Trips (Drum level low). At23:27:12.445 - Unit # 3 Generator Circuit Breaker bus 1 Trips (Drum level low).

At23:27:18.366 - Unit # 4 Generator Circuit Breaker bus 1 Trips (FR oil level turbine trip).

At23:27:38.199 - Unit # 8 Generator tie Circuit Breaker Trips. At23:27:38.202 - Unit # 8 Generator Circuit Breaker bus 1 Trips (EH oil pressure

low). At23:28:20.049 - Unit # 7 Generator Circuit tie Breaker Trips. At23:28:20.183 - Unit # 7 Generator Circuit Breaker bus 1 Trips (under frequency). At23:28.28.911 - Unit # 6 Generator Circuit Breaker tie Trips (turbine speed fail). At23:28.28.911 - Unit # 6 Generator Circuit Breaker bus 1trip. At00:02.48.268 - Barmer 400 line breaker trip manually OFF.

As per PMU data & Rajwest Report: It is inferred from PMU that initial fault was in B-phase.

As per ICT DR Printout, it seems that antecedent current on 400kV side was ~1.2kA means ~800MW power flow through this ICT which corroborated that ICT at Barmer tripped before this point of time.

It is inferred from PMU frequency data that dip in the frequency was started at 23:26:49.506hrs.

Fault on the Bus at Jodhpur seems to be cleared in proper time. (PMU Data)

As per DR data it was observed that Rajwest-Jodhpur D/C tripped from rajwest end on DT received from Jodhpur end.

Rajasthan informed that following was the SoE of the incident:

1. 400 kV Jodhpur-Rajwest Line I, Jodhpur-Rajwest Line II and Kankroli Line tripped on

Over-Voltage and other ends tripped on Direct Trip Received Command.

2. Subsequently, a Bus fault due to damage of 400 kV Insulator on Bus B occurred which

resulted into tripping of ILT-2 Main Breaker.

3. 400 kV Barmer-Rajwest Line and ICT1 at 400 kV Barmer were connected in the same dia

and the Main Breaker of Rajwest line was off for attending hot jumper (due to severe

sand storm) connected to the Main Breaker . Due to tripping of 400 kV Jodhpur-Rajwest

Line I, Jodhpur-Rajwest Line II, the load flow increased on Rajwest-Barmer Line resulting

in Overloading of ICT 1 (only one ICT installed at the GSS) which tripped on Overload

and current recorded 480A appox.

4. 400 kV Barmer-Rajwest Line remain closed from Rajwest end.

All 6 Nos. generating units connected on 400 kV systems tripped at Rajwest due to non-

availability of 400 kV Lines. Voltage recorded at Jodhpur at 23.00 Hrs. was 426 kV.

PSC recommended following: Availability of over current protection on 400kV Barmer-Rajwest line needs to be

looked into (Action:RRVUNL).

Tripping of tie CB at Jodhpur on over voltage protection needs to be established. (Action: RVPNL).

PSC requested RVPNL to submit report on above aspects within 15 days.

aa. Multiple tripping at 400kV Kawai & Chabra Station

i. Multiple tripping at 400kV Kawai & Chabra Station on 19th April 2014 & 20th Apr

2014 at 06:56hrs & 16:08hrs

ii. Multiple tripping at 400kV Kawai & Chabra Station on 29th April 2014 at 11:33hrs

iii. Multiple tripping at 400kV Kawai & Chabra Station on 30th April 2014 at 12:01hrs

iv. Multiple tripping at 400kV Kawai & Chabra Station on 4th May 2014 at 14:48hrs

All these incidents were discussed separately and detailed report with recommendations is available on NRPC website at www.nrpc.gov.in/report/Kawai.pdf.

bb. Multiple element tripping at 400kV Dulhasti HEP on 26th April 2014 at 20:55 hrs

Event category: GD-1 Generation loss: Nil Loss of load: 390 MW “As reported at 20:55hrs of 26th Apr 2014, 400kV Kishenpur-Dulhasti ckt tripped on R-phase to ground fault. As only 1 line is connected between Dulhasti station & rest of the grid so after tripping of the same line, units at 400kV dulhasti station were not have any outgoing line and units were tripped later on due to unavailability of outgoing line.” As per PMU data it inferred that fault was in Red & Blue phase. As tree fell on line due landslide in that area i.e. double phase to ground fault occurred in 400kV Kishenpur-Dulhasti line & tripped all three phase simultaneously. Representative from NRLDC stated that many times, detailed report & DR/EL was provided by constituent at the time of meeting instead of 24 hrs as mentioned in the Grid Code (As per Clause 5.2.r) Detailed Report along with DR/EL from NHPC/POWERGRID was awaited. PSC advised NHPC/POWERGRID to submit detailed report to NRPC sect. & NRLDC. cc. Multiple element tripping at 132kV SEWA-2 station on 29th April 2014 at 17:54

hrs

Event category: GD-1 Generation loss: Nil Loss of load: 117 MW “As reported at 17:54hrs of 29th Apr 2014, Y phase to ground fault occurred in 132kV Kathua-SEWA2 ckt and at the same time all 3 running unit of SEWA2 also tripped on GT over current stage-2.” As per PMU data fault persisted in the system for ~860ms & fault was in Yellow phase. Preliminary Report and DR of Sewa2-Kathua ckt has been received from NHPC but detailed report is still awaited. Report was awaited form PDD J&K

Representative of NHPC informed that protection at 220 kV Heeranagar station is not proper. SEWA-2 units have setting of backup over current/earth fault protection as definite time with 500-600ms time delay. PSC advised to temporarily change the zone-3 time delay setting as 450ms and regularly take up the issue with PDD J&K. PSC expressed concern over large number of tripping in that area and requested NHPC to hold a meeting with PDD, J&K to discuss about the protection coordination & settings at both end and preventative measures to be taken by PDD. No representative from PDD J&K attended the meeting. PSC recommended following: Delayed clearance of fault needs to be looked into as it is serious cause of concern.

(Action: PDD J&K)

As per SoE 132kV Sewa2-Heeranagar ckt-2 tripped. It needs to be reviewed. (Action: PDD J&K)

As reported fault was in 132kV Kathua-Sewa2 ckt then tripping of the same line from Sewa2 in zone-3 needs to be looked into. (Action: NHPC)

As per DR printout it seems 132kV Sewa2-Kathua ckt tripped in 250ms at 17:54:57.788hrs but as per PMU fault got clear at 17:54:58.720hrs, it means fault was existing in the system. This aspect needs to be examined. (Action: PDD J&K, NHPC)

It seems SoE data of SEWA2 is not time synchronized. Immediate action should be taken for time synchronization. (Action: NHPC)

Setting at units of SEWA2 needs to be looked into. (Action:NHPC)

NHPC and PDD,J&K were requested to submit report covering above aspects within 15 days. dd. Multiple element tripping at 400kV Agra(PG) on 02nd May 2014 at 18:03

hrs

Event category: GI-2 Generation loss: Nil Loss of load: Nil “In antecedent condition 400kV Bus-2 at Agra (PG) was under S/D (from 10:14hrs to 19:02hrs) for replacement of R-ph CVT. 400kV Agra(PG)-Sikar-2 manually opened at 16:55hrs on over voltage. 400kV Neemrana-Sikar-1 manually opened at 16:56hrs on over voltage. 400kV Bhiwadi-Neemrana-1 manually opened at 16:59hrs on over voltage. As reported at 18:03hrs of 2nd May 2014, 400kV Agra-Bassi ckt1, Agra-Sikar ckt1, Agra-Bhiwadi ckt1, Agra(PG)-Agra(UP) D/C & Agra-Jaipur(South) ckt2 tripped on over voltage protection operation.” As per SCADA data, voltage was ~435kV maximum at Agra Bus. As per PMU data fault was not observed in the system at the same time.. POWERGRID informed that On 02/05/2014, Bus-II was under shutdown for replacement of “B” phases faulty CVT. At 18:02:18 Hrs, over voltage protection was operated at Bassi end & Direct Trip was received in Bassi Line at Agra end and Agra-Bassi Line Tripped.

At 18:03:13 Hrs, over Voltage (257KV in B Ph) occurred in Agra(UP) line-1, Direct Trip was sent and main and tie breaker opened. Due to opening of Tie breaker, Agra(UP) Line-2 also Tripped because it was charged through Tie Breaker due to Bus-II was under shutdown. At 18:03:14 Hrs, over voltage (256KV in Y Ph) occurred in Sikar-I line, Direct trip was sent to Sikar and main and tie breaker opened. At 18:03:18 Hrs, over voltage (255.049KV in Y Ph) occurred in Bhiwadi-I Line, Direct Trip was sent and main and tie breaker opened. Due to opening of Tie breaker, Jaipur(S)-I also tripped because it was charged through Tie Breaker due to Bus-II under shutdown condition. Following action need to be taken by POWERGRID: Reason of difference of 8 second between Agra end & Bassi end needs to be

explained. Time synchronization of DR of 400kV Agra end of Agra-Bhiwadi ckt should be done. Reason of Main-II distance protection operation in 400kV Agra-Sikar 1 at Agra end

instead of reported over voltage protection to be explained. PSC requested POWERGRID to take up above issues at their level and report the corrective measures to NRPC/ NRLDC within 15 days. ee. Multiple element tripping at 220kV Station Samaypur(BBMB) on 3rd May 2014 at

17:38hrs

Event category: GD-1 Generation loss: 400 MW Loss of load: 420 MW “As reported at 17:38hrs of 3rd May 2014, while charging 220kV Samaypur-Ballabgarh ckt1 from Samaypur end after cancellation of PTW(Permission to work) Y-phase limb of wave trap got damaged and at the same time multiple element tripping occurred at 220kV Samaypur station”. Name of the tripping elements are given below: 220 KV Samaypur-Ballabgarh(BBMB) triple ckt 220 KV Samaypur-FGPP ckt-1 Unit #2 & #3 of BTPS(100MW each) 400/220kV ICT-2 220kV Bus Sectionaliser & Bus Coupler As per PMU data it seems fault clearing time was ~400ms. All 3phases show dip in the voltage. As per Detailed report received from BBMB: 220KV Ballabgarh- Samaypur Ckt. -1 was under shutdown from 30.04.14 to 03.05.14 for overhauling of Red phase pole of ABB make SF-6 CB under supervision of ABB service engineer. After completion of overhauling job, all the operations were completed from both the ends. At 17:38 Hrs / 03.05.14, on charging of 220KV Samaypur- Ballabgarh Ckt.- 1 from Samaypur end, following events / trippings occurred on 220KV Ballabgarh- Samaypur Ckts at respective ends. Relay indications are mentioned below: Sr.

No 

Name  of 

Circuit 

Ballabgarh end  Samaypur end 

1  220KV‐

Samaypu

r ‐1 

CB in open positions & Line  and Bus 

isolators in closed position 

MiCOM P442(M1): St.Ph ABC, Trip Ph 

ABC,  Trip  Zone‐1,  17:38:25:973  Hrs, 

A/R  L/O  Shot,  Fault 

Duration:407.1ms,  Relay  Trip  Time 

505.1ms,  Fault  Location:  2.037Km, 

Ia=0,  Ib=23.17KA,  Ic=0, Van=133.6kv, 

Vbn=57.71kv,Vcn=128.1kv,Fault 

Resistance=310.2 mili ohm 

EPAC:  St  phase  ABC,  Trip  Ph  ABC, 

Dist. 2.5km, Z‐2 

2  220KV‐

Samaypu

r ‐2 

MiCOM P442(M1): St.Ph CN, Trip Ph ABC, Trip Zone‐1, 17:38:26:781 Hrs, Fault Duration:  61.48ms,  Relay  Trip Time  84.7ms,  Fault  Location: 2.052Km,  Ia=377.9A,Ib=1.192KA, Ic=11.10KA,  Van=149kv, Vbn=97.71kv,Vcn=40.64kv,    MiCOM P442(M2): St.Ph CN, Trip Ph C,  Trip  Zone‐1,  17:38:26:775  Hrs, Fault Duration:  59.82ms,  Relay  Trip Time  79.76ms,  Fault  Location: 71.04m,  Ia=376.8A,  Ib=1.167KA, Ic=11.16KA,  Van=133.4kv, Vbn=134.2kv,Vcn=6.432kv 

MiCOM P442(M1): St.Ph C, Trip Ph C, Trip  Zone‐1,  17:38:18:719  Hrs,  Fault Duration:  51.51ms,  Relay  Trip  Time 91.39ms,  Fault  Location:  2.302Km, Ia=371.2A,Ib=1.166KA,  Ic=17.02KA, Van=128.8kv, Vbn=127.3kv,Vcn=44.17kv,Fault Resistance=172.2 mili ohm 

MiCOM P442(M2): St.Ph CN, Trip Ph C,  Trip  Zone‐1,  17:38:26:778  Hrs, Fault  Duration:  61.48ms,  Relay  Trip Time  79.76ms,  Fault  Location: 2.308Km,  Ia=373.3A,  Ib=1.170KA, Ic=17.16KA,  Van=128.9kv, Vbn=127.5kv,Vcn=44.21kv,Fault Resistance=116.8 mili ohm 

3  220KV‐

Samaypu

r ‐3 

Facia: SF6 Gas Pr Low, MiCOMP442: 

Open Manually,  

Tripping through BBP Trip Relay 

4  220KV  Samaypur  ‐  FGPP‐1,  220KV  Side  of  ICT‐2,  220KV  Bus  Coupler‐1,  220kv  Bus 

Sectionalizer  (connected on Bus‐2A)  at  Samaypur  Substation  also  tripped  through Bus 

Bar Protection Trip Relays Relay indication on Bus Bar Protection Panel: Aux CHK Zone 

30CH; AUX LBB‐ 30LBB; Trip Relays 196 (Ballabgarh‐1), 396 (Bus Coupler‐1), 496 (FGPP‐

1), 696 (Ballabgarh‐3), 996 (ICT‐2), 1096(Bus Sectionlizer) of Bus 2A.  

Report about damage of equipment & Analysis Report

(a.) 220KV Ballabgarh – Samaypur Ckt.-1: Bursting of 220KV Yellow phase P.T. (Telk make –DOC 12.03.2013) and due to bursting of PT, porcelain collars of 3 Nos. 198KV LAs, Red Phase CVT, 3 Nos. posts of line isolator and Blue phase CT also damaged at Ballabgarh end. In addition to the above, Yellow phase pole of ABB make SF-6 CB (DOC: 09.04.89) damaged and wave trap of Red phase also damaged and remain in hanged position and touched the line isolator at Samaypur end.

(b.) 220KV Ballabgarh – Samaypur Ckt.-3: Yellow phase pole of CGL make CB got damaged with hitting of porcelain splinters of damaged PT of Samaypur Ckt.1 at Ballabgarh end.

(c.) From the perusal of DR of 220KV Samaypur – Ballabgarh Ckt.-1 at Samaypur end, it has been observed that CB at Ballabgarh end was in open position and Samaypur end was charged 1st. On charging the circuit, voltage of 220KV Yellow PT at Ballabgarh end

recorded a variation from 80kV to 187kV (ph-n) which indicated that some internal fault developed in the PT on charging and caused rise of fault current about 23KA. MiCOM P442 at Samaypur end, initiated Any Trip B (Yellow phase) at 17:38:25:9695 but Yellow pole of CB did not actually open (however CB 52a –auxiliary contact got open at 17:38:26:0025). Flow of fault current about 22KA to 24KA in Yellow phase continued resulting Any Trip B not to reset. At 17:38:26:3050 MiCOM P442 further initiated Any Trip A & Any Trip C also. Thus Any Trip B remained initiated along with fault current in Yellow phase for more than 355 ms resulting in LBB operation of Samaypur – Ballabgarh Ckt-1. From the analysis DR of Disturbance Recorder-2 of Bus Bar Protection (MiCOM P442), LBB operated at 17:38:26:3345 (time of OPTO Input of LBB aux contact for DR). Ballabgarh Ckt.-1 was connected on Bus 2A, hence Bus Bar Protection Trip Relay 196 (Ballabgarh-1), 396 (Bus Coupler-1), 496 (FGPP-1), 696 (Ballabgarh-3), 996 (ICT-2), 1096(Bus Sectionalizer) operated and causes tripping of all the circuit connected to Bus 2A. In the meantime, yellow phase pole of CB got damaged at Samaypur end due to flow of fault current about 24KA for around 450ms.

(d.) The bursting of Yellow phase PT at Ballabgarh end also caused tripping of 220KV Ballabgarh- Samaypur Ckt.-2 at both ends due to occurrence of Blue phase fault as observed from DR of 220KV Samaypur-Ballabgarh Ckt.-2

(e.) The damage of Red phase wave trap at Samaypur end may be due to flow of fault current in red phase as observed from DR of 220KV Ballabgarh-Samaypur Ckt.-1

(f.) Bus 2A at Samaypur end has been charged at 19:09 Hrs / 03.05.14 through Bus Sectionalizer. ICT2 and 220KV Samaypur- FGPP-1 was charged at 19:15 Hrs & 19:29 Hrs respectively on 03.05.14. 220K Samaypur- Ballabgarh-2 was charged at 00:03 Hrs / 04.05.14.

ff. Complete blackout at 220kV Sarna Station on 5th May 2014 at 09:49

hrs

Event category: GD-1 Generation loss: 118MW (As per NHPC Report) Loss of load: 160MW NRLDC informed that at 09:49hrs of 5th May 2014, Y-phase CT of Bus coupler at Sarna station bursted, as bus bar protection at 220kV Sarna station was not available so it resulted into tripping of all 220kV lines from remote end except 220kV tibber ckt.” Name of the tripping elements are given below: 220kV Udhampur-Sarna 220kV Kishenpur-Sarna D/C 220kV Dasuya-Sarna ckt-1&2 220kV Hiranagar-Sarna 220kV Jammu-Sarna 220kV Batala-Sarna all 4Circuits 220kV Tibber-Sarna 220/132kV ICT 1&2 132kV Hiranagar-Sewa ckt-1&2 132kV Sewa-Kathua 132kV Sewa-Mahanpur All 3 Units of 132kV SEWA-II ~ 129MW As per telephonic conversation with SEWA-II, 220kV Sarna-Hiranagar had tripped on fault During this period, all 4 lines connected to Sewa-II tripped and no line voltage was available from remote end As per PMU data it seems fault persisted in the system for ~680ms & dip was in R & Y-

phase. NHPC informed that all units of Sewa-II tripped due to non-availability of lines.for evacuation. Flag details received from 220kV Sarna station is mentioned below:

TRIPPING DETAIL AT 220  KV S/S SARNA ON DATED 5/5/14 AT 9:48

SR NO. NAME OF CKT INDICATION AT SARNA SIDE INDICATION AT OTHER SIDE

1 220 KV SARNA W/G‐1 NO TRIPPING

MAIN‐1 NILL, MAIN‐2(MICOM‐RYBǿ 

Z2)

2 220 KV SARNA W/G ‐2 M‐1 ABC ǿ M‐1 (ABǿ,) M‐2: (MICOM‐RYBǿ &Z2)

3 220 KV TIBBER QUADRAMOH‐A & AUTO RECLOSER & 86 NO TRIPPING

4 220 KV SARNA W/G ‐4 NO TRIPPING M‐1( MICOM RYBǿ & Z2,) M‐2 NILL

5 220 KV SARNA RSD‐1 NO TRIPPING

M‐2 (QUADRAMOH‐21 ǿ ABC ǿ & 86) 

M‐1 NILL

6 220 KV SARNA RSD‐2 NO TRIPPING

M‐2 (QUADRAMOH‐21 ǿ ABC ǿ & 86) 

M‐1 NILL

7 220 KV SARNA RSD‐3 NO TRIPPING M‐1( QUADRAMOH Bǿ E/F,) M‐2 NILL

8 220 KV SARNA DASUYA‐1 NO TRIPPING M‐1 (RYB ǿ & Z2,)M‐2 NILL

9 220 KV SARNA DASUYA‐2 NO TRIPPING

M‐1 (P442‐RYBǿ Z2,RXM H2 

OPRATED ) M‐2( REL‐670 GROUND 

TRIP,Ryǿ Z2)

10 220 KV KISHANPUR ‐1 NO TRIPPING

M‐1( MICOM‐ABN &Z2,) M‐2 (D‐60 

Yǿ G

11 220 KV KISHANPUR‐2 NO TRIPPING

M‐1( MICOM‐ABN &Z2,) M‐2 (D‐60 

Yǿ G

12 220 KV HEERANAGAR NO TRIPPING E/F

13 220KV UDHAMPUR NO TRIPPING E/F & 16 A,186 B

14 220 KV BUS CUPPLER E/F

15220/132 KV 100 MVA AUTO T/F T‐1 

220 KV SIDE O/C R&Y ǿ

16220/132 KV 100 MVA AUTO T/F T‐1 ‐

132 KV SIDE O/C Y ǿ MASTER TRIP

17220/66 KV 100 MVA  T/F T‐2 220 KV 

SIDE NO TRIPPING

18220/66 KV 100 MVA  T/F T‐2‐ 66 KV 

SIDE NO TRIPPING PSC recommended following remedial actions: Non-availability of Bus Bar Protection at 220kV Sarna station needs to be looked into.

As it is clear violation of CEA Grid connectivity standards. (action: PSTCL)

SCADA data & SoE are not configured at 220kV Sarna station due to problem in RTU at Sarna Station. (Action: PSTCL)

In DR of SEWA-2 there is issue of RYB with ABC in configuration. This should be corrected immediately. (Action: NHPC)

Representative of PSTCL informed that Bus Bar Protection at Sarna is being commissioned and same would be completed by 31st July, 2014. PSC advised PSTCL and NHPC to submit report covering above aspects within 15 days.

A.3 Compliance to Hon’ble CERC’s directions in the Petition no. 220/MP/2012 SE(O), NRPC informed that Hon’ble Central Electricity Regulatory Commission’s order in the Petition no. 220/MP/2012 was placed as item 6.2 (ii) in the agenda notes of

the 98th OCC meeting held on 22.04.2014 for information and compliance by members. SE (O), NRPC had briefed the members about the contents of the order and had requested members for its compliance. But no utility had submitted the action plan thus far for rectification of deficiencies in the protection system observed in respective power system for compliance within the stipulated time schedule. CTU/STUS were once again requested to submit action plan for rectification of deficiencies in protection system of their network with time schedule for completion in the following proforma:-

Action Plan for rectification of deficiencies in protection system Date:

Name of Transmission Utility:-

Name of Sub-station:-

S.

No .

Brief description of deficiency

Please tick appropriate type of deficiencies

Action

Plan to rectify deficiencies in protection system indicating intermediate milestone with dates.

Date on

which complete rectification of deficiency is expected.

Compliance

w.r.t. time schedule indicated and constraints , if any in compliance thereof

Remarks

Category-

A (Where no procurement is involved)

Category-

B (Where procurement is involved)

1

2

3

4

5

6

7

In accordance with Hon’ble CERC’s Order in the Petition no. 220/MP/2012 i.e.20.04.2014

Category-A: Completion of rectification of deficiencies in the protection system is to be completed within two months of the issue of the Order.

Category-B: Completion of rectification of deficiencies in the protection system is to be

completed within six months of the issue of the Order.

In case of non-completion of deficiencies under Category-A, In-charge of SLDC has been empowered under this Order (in Petition no. 220/MP/2012) to approach respective state Commission as guided under Para no. 27 (d).

CTU has also been empowered under this Order at Para no. 27(e) to take necessary action and

issue a show cause notice for disconnection to sub-station of STU for not complying with the Standards for Protection and Control as per Central Electricity Authority (Technical Standards for Construction of Electric Plants and Electric Lines) Regulations, 2010 and Central Electricity Authority (Grid Standards) Regulations, 2010.

All utilities were requested to submit the information in prescribed format by 31st May, 2014.

A.4 Follow up action on outstanding issues from previous meetings

A.4.1 Protection related issues at 400 kV switchyard of Mahatma Gandhi TPS

It was decided in 25th PSC that HVPNL and JPL would hold a separate meeting within a week to resolve the protection coordination relates issues. The discussion and decision of the meeting were to be intimated to NRPC secretariat with a copy to NRLDC. Issue could not be discussed as no representative from JPL attended the meeting. HVPNL was requested to coordinate the meeting and resolve the issues at the earliest.

A.4.2 Non-functional carrier-inter-trip feature

SE(O), NRPC informed that in 23rd PSC meeting, BBMB had intimated that carrier-inter-trip feature (Carrier aided protection of transmission line) of following lines was not enabled due to faulty PLCC channels (of PSTCL and HVPNL ends). Status as updated in 25th PSC is as under:

PSTCL informed that PLCC for 220 kV Jamalpur-Dhandari-I, Jalandhar-Butari, Jalandhar-Jamsher-I&II was functional and can be tested jointly. Further, work on Jamalpur-Dhandari-II would take some time as the protection coupler is of a firm which has been blacklisted recently.

Sr.No Transmission Line (220 KV)

This end Other end

Status as updated in 26th PSC

1 Jamalpur-Dhandari-I&II

BBMB PSTCL As per PSTCL PLCC is functional for ckt.-1

2 Jalandhar-Butari

BBMB PSTCL As per PSTCL PLCC is functional.

3 Jalandhar-Jamsher-I&II

BBMB PSTCL As per PSTCL PLCC is functional.

4 Barnala–Lehra-Mohabbat

BBMB PSPCL BBMB to take up the matter bilaterally with PSPCL with an intimation to NRPC secretariat

5 Samaypur-Badshahpur BBMB HVPNL It will take 06 months.

6 Samaypur-Palwal-I&II

BBMB HVPNL It will take 06 months.

7 Samaypur-Palli-I&II

BBMB HVPNL It is functional and can be tested.

8 Bhiwani-Bapora-I&II

BBMB HVPNL It is being used as radial line. So PLCC not required.

HVPNL informed that PLCC for 220 kV Samaypur-Palli-I&II is functional. Further Samaypur-Badshahpur and Samaypur-Palwal-I&II PLCC rectification will take another 06 months. It was agreed that BBMB would jointly test the functional PLCC with PSTCL and HVPNL and report the result in the next PSC.

A.4.3 Non- availability/ defective PLCC Link of SEBs Lines terminated at POWERGRID (NR-2) substations

SE(O), NRPC stated that POWERGIRD had submitted a list of sub-station in 22nd PSC meeting where PLCC was non-functional at other side. During 25th PSC meeting POWERGRID was requested to test the links made functional by PSTCL and HVPNL and discuss the remaining issues, if any, in next PSC meeting.

The status as updated during the meeting is enclosed as Annex-II

A.4.4 Islanding scheme for Rajasthan, NAPS and Haryana

A. SE(O) recalled that during 25th PSC meeting representative of NAPS had informed that they were agreeable to make islanding operational at 47.9 Hz and same would be implemented by 15th April, 2014. Representative of NAPS informed that scheme has been implemented making islanding operational at 47.9 Hz. SE (O), NRPC requested NAPS to submit the scheme as implemented to NRPC sect. with a copy to NLRDC. B. SE(O), NRPC stated that the issue regarding islanding scheme for Rajasthan was discussed in 23rd PSC meeting held on 05th Sept. 2013 wherein certain suggestions were made by the members. Responding to these suggestions, RVPNL vide letter dated 04th October, 2013 had informed that inclusion of Mahi-I and II would help to mitigate the load fluctuation in proposed islanding of RAPP-A and B. Further RVPNL had proposed to change the frequency from 47.9 Hz to 48.0 Hz on the pretext that CERC has also revised the setting in band of 49.7 Hz to 50.2 Hz. Further RVPNL had suggested that in the event of grid disturbance auxiliary supply of RAPP-C be met from RAPP-B instead of Anta-GTPS. It was proposed that in the event of grid disturbance 220 kV S/C RAPP-B – Anta GTPS line should be kept in service and 220 kV S/c RAPP C-Anta GTPS line should be opened by the operation of under frequency based islanding scheme.

In its 25th meeting, PSC was of the view that Mahi-I and II should not be part of islanding scheme for RASP-I and II as Mahi is connected to RAPS with long line. Further Mahi-I and II do not generate power continuously. So including Mahi-I and II would not serve the purpose of mitigating load fluctuation. PSC agreed with the suggestion that auxiliary supply of RAPP-C be met from RAPP-B instead of Anta GPS. PSC was of also of the view that all islanding scheme in Northern Region are being planned to operate at 47.9 Hz and Rajasthan should also adhere to same. It was decided that RVPNL would revised the scheme in line with deliberations and resubmit the scheme. However. RVPNL has reiterated its stand. No consensus could be arrived at regarding the inclusion of Mahi-I and II in the scheme. PSC decided that matter may be referred to CEA C. SE(O), NRPC informed that HVPNL had submitted islanding scheme for the state. PSC was of

the view that estimated available generation and load in the island are in close proximity and therefore the island, if formed, might not survive. Further it was requested that HVPNL may discuss the scheme with NTPC as their Faridabad gas station is a part of the proposed islanding scheme. HVPNL had agreed to review the scheme.

Further during 25th PSC meeting HVPNL informed that they would hold a meeting within 15 days with NTPC and would report the discussion to NRPC secretariat. Representative of HVPNL informed that discussion with NTPC was pending and same would be done within a weeks’ time. A.5 Third Party Protection Audit by the Protection Experts for intra-state system/ balance system not covered in Basic Protection Audit.

Status as updated during the meeting is enclosed as Annexure-III

SE(O), NRPC informed that Protection audit at NHPC (for Baira Siul HEP), APCPL (for Indira Gandhi STPS, Jhajjar) and NPCIL (for RAPP) has already been carried out by teams of protection experts constituted by NRPC. In case of HVPNL and DTL, audit had been carried out at two sub-stations each. Further teams had already been constituted for 02nos. sub-stations each of HVPNL and DTL, One sub-station each of PTCUL and HPSEB Ltd and DCRTPP of HPGCL. Theses utilities were requested to submit action plan for rectification of deficiencies, if any, observed in the audit.

A.6 Status of Bus bar protection

SE(O), NRPC informed that during 21st, 22nd , 23rd , 24th and 25th PSC meetings utilities were requested to update the status Bus Bar Protection available with NRPC secretariat. Only DTL, BBMB PSTCL, POWERGRID, NHPC and HPSEB Ltd. had submitted the status. Updated status enclosed as Annexure-IV. He requested other utilities to submit the status within 15 days. Status as updated in the meeting is given as Annexure-IV A.7 Implementation of decision taken in 25th PSC: Decision of 25th PSC has been compiled and same was attached as Annex-III of agenda. Members may go through the consolidated decision and update the status of the implementation part of the decisions. On Sr. No. 3 issue of multiple element tripping at 220 kV Tanakpur sub-station it was decided that POWERGRID would carry out the protection audit of CB Ganj within 15 days. On the issue of multiple element tripping at 220 kV Unchahar it was earlier decided that SRM module of LBB protection needs to be replaced. NTPC informed that PO has been placed and same would be replaced within a month.

SE(O), NRPC requested utilities to submit updates within 15 days.

A.8 Blackout at CLP Jhajjar(Agenda by JPL) On 13th may, 2014 at 03:52 hrss. The JPL-Kabulpur ckt.#1 tripped on distance protection. The voltage was on the higher side in the early hours. At 05:01 Hrs. the JPL-Dhanonda circuit-1 and JPL-Dhanonda circuit-II tripped on Direct Trip Receive Signal from Dhanoda sub-station because of line over voltage. The grid voltage was still not within control and finally the last feeder at our station JPL-Kabulpur circuit-2 tripped at 05:10 hrs. on overvoltage putting the station on blackout. JPL have also observed severe voltage fluctuations in Dhanoda D/C and Kabulpur D/C lines several time. Many occasions units

were at the verge of tripping and same has brought to your notice several times. We have requested you to take necessary measure to stabilize tile grid to avoid any re occurrence. Issue could not be discussed as no representative of JPL attended the meeting

Additional Agenda for 26th PSC Meeting

AA.1 Mock testing of SPS for Interruption of import by NR at 765 kV Agra SE(O), NRPC informed that Mock testing of SPS for Interruption of import by NR at 765 kV

Agra (from WR), was done on 03rd April, 2014. The testing was coordinated by NRLDC. Following clarifications were required from states and POWERGRID:

1. PSTCL, UPPTCL and RVPNL should submit the information as per the format given at the

time of testing. 2. RVPNL, HVPNL, BBMB, PSTCL, UPPTCL should submit report on nonoperation/non-

installation of SPS at designated sub-station. 3. POWERGRID to submit the list of sub-stations where the scheme has been installed.

The result of mock testing as per details made available to NRPC Sectt is as under:

State Name of Sub-station Load Relief expected if SPS

would have operated on 24.12.2014(MW)

Remarks/Report not received

Punjab - - Gobindgarh, Jamsher, Mohali, Laltokalan

UP Mainpuri 75 Modipuram and Nara HVPNL Narwana 15 BBMB Panipat 20

Samaypur 163 RVPNL - - Alwar, Bhilwara, Kota,

Merta

PSTCL informed that scheme had operated at Gobindgarh and Laltokalan sub-station but inoperative at Mohali and Jamsher sub-stations. Representative if RVPNL informed that terminations are pending at Kota substation. SE(O), NRPC requested the utilities to submit the shortcoming in the SPS operation at their end to POWERGRID so that corrective action can be taken at the earliest.

AA.2 PLCC and protection related issues related to DTL The PLCC issues are as follows: S.

No. Name of Line Details of PLCC

A. Ballabhgarh S/s

1. 400kV Ballabhgarh-Bamnauli-I Some portion of overhead transmission line has been replaced with underground cable at Bamnauli end. Attenuation of PLCC signal is very high due to cable. PLCC is out of service in B’Garh-B’nauli & J’kara-B’nauli since 06.04.14 & 27.12.13 respectively. ABB confirmed that modification is required in LMU to match modified line impedance with cable impedance.

2. 400kV Ballabhgarh-Bamnauli-II

B. Jhatikara S/s 3. 400kV Jhatikara- Bamnauli-I

4. 400kV Jhatikara- Bamnauli-II

Representative of DTL informed that the problem would be rectifed within six months.

AA.3 PLCC and Auto Re-closure issues related to UPPTCL

SE(O), NRPC stated that there are various lines of UPPTCL wherein PLCC panels and auto recloser schemes are not in working condition due to which frequent tripping of lines on transient faults are taking place. Status and problem of PLCC and Auto recloser was enclosed at annexure-I of additional agenda. UPPTCL was requested to submit their reply on the issue within a week.

AA4. Additional Discussion on Tripping at CGPL Mundra at 19:21hrs of 12th Mar 2014:

Representative from NRLDC informed that, letter dated 24.03.2014 was written to all the NR constituents regarding tripping of all 5 running units of CGPL-Mundra. It resulted in the dip of 0.67Hz in frequency. It was a good case for analysis of FGMO/ RGMO response in the generating units but no information has been received except Karcham & Chamera-1. Karcham has informed only about the non-tripping of any element and data regarding the FGMO/RGMO response was not provided. Chamera-1 provided data but it was SEM data of 15minute time block, from which analysis of FGMO/ RGMO was not possible. DF/DT operation of 0.1Hz/sec also reported in Western Region. In NR, Rajasthan informed that DF/DT protection didn’t operate in their state. Other states were not reported any operation of DF/DT protection. It was agreed that digital as well as analog data of feeders under UFR & DF/DT relay should also be configured & monitored in State SCADA display and same data should be provided to NRLDC so that NRLDC can also configure it in their SCADA Display.

Annex-I

List of Participants for 26th Protection sub-Committee meeting held on 23.05.2014 at NRPC, New Delhi

Name Designation Organization Phone/Mobile e-mail ID

Ankit Gupta Engineer NRLDC 9560270520 ankitinf06@gmail.com

Nitin Yadav Sr.Engr NRLDC 9560050257 yadavnitin06@gmail.com

Abhishek Jain Dy.Manager APCPL 9416212489 abhishekjain01@ntpc.co.in Lakai Chand EE UPPTCL 9412738898 nigamlc@gmail.com

Rajbir Singh ASE PSTCL 9646118223 xenprotectionludhiana@yahoo.in Mohd.Zia AGM(OS) NR NTPC 9415005883 mohdzia@ntpc.co.in

Anmol Sindhi AGM(OS) NCR NTPC 9650993073 anmol.sindhi@yahoo.com

B.L.Gujar Manager(Prot) DTL 9999533985 bharatlalgujar@gmail.com Sanjay Jhamtani Scientific Officer’F’ NPCIL 09413356912 sjhamtani@npcil.co.in

M.K.Bhatnagar Scientific Officer’F’ NPCIL 9412768292 mkbhatnagar@npcil.co.in

Y.S.Gulia Exe.Engineer HVPNL 9354194830 xenmpcctk@hvpn.gov.in Rajender Singh Redhu ADIPRT BBMB 9466121202 rsinghredhu@yahoo.com

Sukhvinder Kumar DDO(P&T) BBMB 9466119190 skbadhan@yahoo.com Anil Raghuwanshi Dy.Manager THDCIL 8755900785 anil.raghuwanshi1982@gmail.com

L.P.Joshi AGM THDCIL 8755900790 lp.joshi@yahoo.co.in

Vinod Kumar Gupta DGM POSOCO 9873549068 vkgupta-pg145@yahoo.co.in D.S.Chauhan Manager THDCIL(NLDC) 8171000342 dineshchauhan87@gmail.com

S.P.Bansal Xen(Electrical) RRVUNL 9413385170 stpscr1@gmail.com

C.P.Himanshu SE(Elect) Chhabra ThermalP.P(RRVUNL)

094133-85980 ctppse-elecx@hotmail.com

S.P.Jamal Sr.Xen HPSEBL 94181-22067 EEPtdk10@gmail.com

A.K.Baid Dy CE/MP & S RVPNL 9414061186 ce-m&p@rvpnl.com A.K.Arya Xen(PC) RVPNL 9414061066 se.ldrvpnl@gmail.com

M.K.Singhal Xen(Prot) RVPNL 9414061406 xen_prot_i_jaipur@rvpn.co.in

Name Designation Organization Phone/Mobile e-mail ID G.A.Badu Dy.Mgr(E) NHPC 7840054755

S.K.Mishra Manager(E) NHPC 9910103478 skm.nhpc@yahoo.in

Janardan Chaudhary GM(O&M) NHPC 9958819003 Jchoudhary@nhpc.nic.in

M.S.Hada Manager(O&M) POWERGRID 9650555997 mshada1@gmail.com

R.Sudan DGM(OS) POWERGRID 9419213490 sudanrajeev@gmail.com

M.Shukla G.M(T)CS IPGCL/PPCL Delhi 9717699229 mshukla.ipgpp@nic.in

Uday Trivedi ADANI 9099055059 Uday.Trivedi@adani.com

Rajiv Porwal CM NRLDC 9871581133 rajivporwal@gmail.com

D.K.Jain AGM NRLDC 9910344127 dkj2009@yahoo.co.in

Manoj Das NLDC(Sr.Engr) NRLDC 9650894940 dasmanojk@gmail.com

Rohit Anand Engineer NRLDC 8527758282 rohitanand@gmail.com

Rahul Shukla Engineer POSOCO 9650555388 rahulshukla.nldc@gmail.com

S.C.Sharma Chief Manager PGCIL 9873918526 shubhashs@yahoo.co.in

Satandra Singh EE UPPTCL 9412749881 satandra @gmail.com

Shri Krishna SE(T&C) UPPTCL 9412749817 setncmrt@upptcl.org

Kavindra Singh Advisor UPPTCL 9412749803

Shyamsunder Goyal Engineer NRLDC 8521570959 goyalsunder@gmail.com

Ajay Telegaonkar SE(O) NRPC 9910728144

Naresh Kumar EE(O) NRPC 8860310642

Ratnesh Kumar AEE(O) NRPC 8750628439

Vijay Kumar Consultant NRPC

Gaurav Jasuja AEE(O) NRPC

Annexure-II

Non- Availability/ Defective PLCC Link of SEBs Lines terminated at POWERGRID NR-2 substations

PLCC issues with J&K PDD 

S.No Name of Substation 

Name of Line  Availability of PLCC Status as updated 

in 26th PSC 

1 Wagoora 

220 KV Zainakot‐I  Not Available    

2  220 KV Zainakot‐II  Not Available    

3 

Kishenpur 

220 kV Barn‐I  Not Available    

4  220 kV Barn‐II  Not Available    

5  220 kV Mirbazar  Pending for commissioning by PDD after LILO of 220 kV Kishenpur‐pampore Ckts. 

  

6  220 kV Ramban    

PLCC issues with HVPNL 

1  Panchkula  220 kV Raiwali‐I  Available/Not working  As per HVPNL PLCC has been set right on 25.11.2013. Testing is to be carried out 

2  220 kV Raiwali‐II  Available/ Not working 

3  Abdullapur  220 kV Railway‐I  Not Available  Not Required 

4  220 kV Railway‐II  Not Available  Not Required 

5  Kaithal  220 KV Cheeka‐I  Available / not working  As per HVPNL PLCC has been set right on . Testing is to be carried out 

6  220 KV Cheeka‐II  Available / not working 

7  220 KV Kaithal‐I  Available / not working 

8  220 KV Kaithal‐II  Available / not working 

9  Bahadurgarh  220 kV Noonamajra‐I  Panels available, Pending for commissioning 

As per HVPNL PLCC has been set right on . Testing is to be carried out

10  220 kV Noonamajra‐II  Panels available, Pending for commissioning 

As per HVPNL PLCC has been set right on . Testing is to be carried out

PLCC issues with PSTCL 

01  Ludhiana  220kV Pakhowal  Installed but not working  As per PSTCL PLCC is working. Testing is to be carried out 

02  Amritsar  220kV Verpal ‐I  Not Installed   Issue pending  as OEM has been Black Listed. 

03  220kV Khasa ‐II  Not Installed  By Feb., 2014 

04  220kV Verpal‐ II  Installed but not working  As per PSTCL PLCC is working. Testing is to be carried out 

05  220kV Khasa‐I  Installed but not working  As per PSTCL PLCC is working. Testing is to be carried out 

Annexure- III Third Party Protection Audit

S. No

Constituent(s)/ Utility(s)

Total no. of Sub-stations and Switchyards

Sub-stations/ Switchyards covered in Basic Protection audit

Proposed no. of S/s or S/y for Protection Audit

Agency carrying out Protection Audit

Anticipated/Target completion of protection audit

Status/Remark, if any

1 RRVPNL 132 kV-351 220 kV-86 400 kV-9

220 kV-4 440 kV-4

220 kV-39 400 kV-5

CPRI 8 months TPA of KSTPS & SSTPS has been carried out by CPRI and after examination of audit report, RRVPNL is in correspondence with CPRI on the deficiencies pointed out by them. RRVPNL has submitted the Protection Audit report carried out by CPRI

2 HVPNL 220 kV-56 400 kV- 7

220 kV-1 (Kirori)

220 kV-5 (Tepla, Bastara, Masudpur, Sector-72 Gurgaon & A-5 Faridabad)

From panel of Protection Experts formed by NRPC

- TPA of Sector-72, Gurgaon and A-5, Faridabad has been carried out and report submitted. Further, HVPNL proposed TPA of Tepla & Bastara sub-stations. NRPC Secretariat issued order for protection audit of these two nos. Sub-stns. on 25.04.2014.

3 PSTCL 220 kV-71 220 kV-3 (Sarna, Ajitgarh & Govindgarh)

220 kV-11 From CPRI

- In 96th meeting, it was intimated that work including those of PSPCL stations has been awarded to CPRI.

4 DTL 220 kV-30 400 kV-3

400 kV-1 (Bamnauli)

220 kV-25 From panel of Protection Experts formed by NRPC

- In 95th OCC meeting, DTL had submitted list of 25 nos. 220 kV S/s identified for TPA. Out of these TPA of 400 kV Mundka and 220 kV Shalimarbagh has been carried out. Further, DTL proposed TPA of Rohini-I & Mehrauli sub-stations. NRPC secretariat issued order for protection audit for these two nos. Sub-stns. On 25.045.2014. TPA of Rohini-I and Mehrauli sub-stations has been completed on 13.05.2014 & 15.05.2015 respectively.

5 HPSEB Ltd.

220 kV-8 220 kV-1 (Kunihar)

220 kV-7 From panel of Protection Experts formed by NRPC

Protection audit

carried out on

20.05.2014

In 90th OCC meeting, HPSEBL submitted the list of remaining 7 nos. Substation including 220 kV Jassure Substation for TPA. HPSEBL proposed TPA of Jassure & Baddi sub-

stations. Protection audit of 220 kV Jassure S/s was carried out by team of Protection Experts nominated by NRPC Sectt. on 20.05.2014. Team has submitted the report.

6 UPPTCL 132 kV- 276 220 kV-73 400 kV-14 765 kV-1

220 kV-3 400 kV-14

220 kV-41

CPRI

- TPA of 41 nos. Sub-stations has been awarded to CPRI on 22.01.2014 with the completion period of one year.

7 PTCUL 132 kV-26 220 kV-6 400 kV-2

400 kV-2 220 kV- 4 132 kV- 1

(i) 220 kV Roorkee, (ii) 220 kV Hardwar

(SIDCUL), (iii) 220 kV

Pantnagar (SIDCUL), (iv)

220 kV Kamluaganja & (v) 132 kV

Majra.

From NRPC Team of

Protection Experts

- PTCUL vide letter no. 78/CE(P)/PTCUL dated 18.01.2014 requested to arrange TPA of 5 sub-stations. In this meeting, PTCUL proposed TPA of Roorkee & Haridwar (SIDCUL) sub-stations on priority. NRPC Secretariat issued order for protection audit of Roorkee and Haridwar Sub-stns. on 25.04.2014.

8 UPRVUNL 220 kV-5 400 kV- 2

220 kV-2 (Obra &, Harduaganj) 400 kV-2 (Anpara, Obra-‘B’)

220 kV-3 CPRI Anticipated

completion time-6 months

Order placed on CPRI for TPA on 17.08.2013 in respect of Parichha TPS and on 07.08.2013 in respect of Panki TPS. S/Y of Parichha TPS audited from 26th -28th November, 2013 and S/Y of Panki TPS audited from 30th November, 2013 – 2nd December, 2013. Reports are awaited from CPRI.

9 RRVUNL

220 kV-2 (KTPS, STPS)

Generating Stns-4

CPRI 8 months In 90th OCC meeting, representative of RRVPNL informed that protection audit of KTPS & STPS & DCCPP has been completed. TPA Reports submitted vide letter dt. 17.12.2013. However, DCCPP vide letter dt. 31.01.2014 has informed that CPRI had collected data of Gen. Trafo., testing of Battery banks and PLCC signals. SE(O), NRPC requested to share the report of PA. The representative of RRVUNL informed that the clarification has been sought for on

observation from CPRI. Giral Lignite Power Ltd., Barmer, has submitted a copy of report of TPA done by CPRI of Units # I & II.

10 HPGCL 220 kV-4 (Panipat, Khodri & Yamunanagar)

220 kV-3 (Panipat & Khodri)

Yet to be identified

No information

- HPGCL had requested to take action for TPA of balance Gen. Plants. Accordingly, NRPC would form a TPA team to audit the Generating stations of HPGCL. NRPC vide letter dt. 2nd May, ’14 issued authorization to carry out protection audit of DCRTPP, HPGCL

11 PSPCL 220 kV-3 220 kV-1 (Ropar)

03 Generating stations

CPRI - TPA awarded to CPRI in the order of PSTCL.

12 UJVNL 132 kV-3 220 kV-3

220 kV-1 (Khodri)

1. 132 kV Chilla Power House Switchyard 2. Remaining Switchyard proposed to be carried out by NRPC team of Protection experts.

Proposal for Chilla received from CPRI. Balance by NRPC team of Protection Experts.

- UJVNL had intimated in 94th OCC meeting that the offer from CPRI has been received for Chilla PH. UJVNL was requested to intimate the latest status of TPA regarding award to CPRI.

13 PDD, J&K 132 kV-51 220 kV-10

220 kV-3 Yet to be identified

No information

- PDD, J&K was requested to intimate as to how they propose for TPA

14 BBMB 17 nos. 220 kV S/s and S/y 3 nos. 400 kV S/ss

400 kV- 3 at Panipat, Bhiwani & Dehar 220 kV- 4 at Jamalpur, Samaypur, Ch. Dadri & Ganguwal

17nos.-220 kV, 3 nos.-400 kV

CPRI. (Award placed on 20.05.2013)

1 year (April, 2014)

The work of data collection for analysis by CPRI of all the sub-stations/Grid stations of BBMB has been completed. The ETE testing of the four transmission lines is also completed during December 2013. However the work like checking the healthiness of DC Systems, PLCC and FOC is under progress by CPRI team. The work is likely to be completed by end of April 2014.

15 POWERGRID

220 kV-3 400 kV-43 (incl. of 3 of 765 kV) 765 kV-8 HVDC-5

400 kV-33 765 kV-6 HVDC-5

No Proposal - - -

16 NTPC 220 kV-1 400 kV-9

220 kV-1 400 kV-9

Not required - - No action required.

17 NHPC 132 kV-1 220 kV-5

220 kV-4 400 kV-4

1 (220 kV Baira Siul)

Team of Protection

- Team nominated by NRPC has carried out

400 kV-4 Experts from POWERGRID & HPSEB Ltd. nominated by NRPC

TPA at Baira Siul. NHPC informed that TPA was completed on 5th December, 2013. NHPC intimated the nature of deficiencies observed and action plan submitted to rectify the deficiencies. As per action plan deficiencies shall be expected to rectify by May, 2014 - December, 2014.

18 THDC 400 kV-2 (Tehri & Koteshwar)

400 kV-1 (Tehri)

400 kV- Koteshwar

CPRI July, 2014 The representative of THDCIL informed in this OCC that TPA has been awarded to CPRI with completion schedule of 06 months i.e. by July 2014.

19 SJVNL 400 kV- 1 (Nathpa Jakri)

400 kV-1 Not required - - No action required.

20 NPCIL 220 kV-4 400 kV-1

220 kV-1 (NAPS)

RAPS-‘A’, ‘B’ & ‘C’ (1x200 MW generating unit with 1x200 kV switchyard, 2x200 MW generating units with 1x200 kV switchyard & 2x200 MW generating units with 1x200 kV & 1x400 kV Switchyrds)

From panel of Protection Experts formed by NRPC (proposed)

- TPA has been carried out by the team of protection experts and point wise clarification on observations submitted by NPCIL.

21 APPCL 400 kV-1 400 kV-1 400 kV - 1 From panel of Protection

Experts formed by

NRPC (proposed)

- TPA has been carried out by the team of protection experts and point wise clarification on observations submitted by APPCL.

22 Lanco Power

765 kV-1 (Anpara’C’)

765kV-1 Not required - - Not required

23 JPVL 400 kV-3 400 kV-3 Not required - - Not required 24 AD Hydro 220 kV-1 - Proposed

from CPRI - - -

25 Rosa Power

400 kV - 1 220 kV-1

400 kV- 1 220 kV- 1

Proposed from CPRI

Offer from CPRI

received. Award under

process

- The representative of Rosa Power had intimated that they had received offers from CPRI. Work order placed. CPRI visited the power plant and collected all relevant documents on 30.05.2014. Rosa power handed over all requisite information to CPRI.

Annexure-IV

Status of Bus bar Protection for Northern Region Constituents

State/Constituent TRANSCO/GEN

CO Total No. of Sub

Stations/Switchyards (220 kV and above)

No. of substations/ switchyards where

Bus bar protection is functioning

Remarks Action Plan

Delhi DTL 37 34 At  220  kV  s/stns  namely  Lodhi  Road,  Gopalpur  and  Kanjhawala  it is being planned.  

25 nos. new BBP is being procured. Under Approval Stage

Haryana HVPNL 44 23 Out of 21 substations, BBP has been installed but not commissioned at 09 and has not been provided at 12 

.

Plan not submitted

HPGCL 03 03

Rajasthan RVPNL 85 23 63 nos BBP not functional. 220 kV: 62 & 400 kV: 01 07 nos. are under procurement

RVUNL 05 05

Himachal Pradesh

HPSEB 07 03 For 1 sub‐station, it was defective and at remaining 03 sub‐station,  installation of BBP was not  feasible due to space constraint. 

Punjab PSTCL 60 21 07 nos commissioning in progress

PSPCL 03 03 J&K PDD 06 - Uttarakhand PTCUL 08 -

UJVNL - - BBMB BBMB 23 17 - -Not required at Dhulkote and Jagadhari as

there is no Bus Bar. - For Sangrur Process is intiated. -For Barnala it is to be provided by PSTCL as agreed in PSC-PSTCL will commission it by 31.03.2015 - As per BBMB not required for Sangrur, Kurukshetra and Delhi as no. of feeders is less than five- But PSC decided that it need to be installed  

Uttar Pradesh UPPTCL 82 10 21 nos for 220 kV are under procurement stage. 21 43 UVUNL 05 -

POWERGRID PGCIL 38 38 Central generating Stations

NTPC 11 11 NHPC 09 09 NPCIL 02 02 THDC 01 01 SJVNL 01 01