21
SOUTHERN REGIONAL POWER COMMITTEE BANGALORE
Agenda for the 39th Meeting of
Protection Coordination Sub-Committee of SRPC to be held on 30.12.2014 (Tuesday)
1. Confirmation of the Minutes of the 38th Protection Coordination
Sub-Committee meeting held on 27.11.2014.
2. Compliance Measures with regard to orders of Hon’ble CERC
In Petition No. 146/MP/2013 with I.A. 36/2013 Order Dt. 20.02.2014 The constituents are requested to update the implementation status for Phase I & Phase II activities .
The issue would be discussed in the meeting.
3. Details of Grid Occurrences The Grid Disturbance, Grid Incidences, failure of Auto-reclosing, and O/V tripping to be discussed in the PCSC (as Submitted by SRLDC vide email dt. 12.12.14) is enclosed herewith as Annexure I.
The Constituents are requested to send the following information in respect of Grid Disturbance and the Major Grid occurrences to have fruitful discussions in the PCSC forum. (a) FIR of the Incidence (with DR, EL )
(b) Single Line Diagram of the Substation (with device IDs)
(c) Prefault Condition
(d) Occurrence Details
(e) Remedial Measures taken/suggested by the Substation/Utility/SLDC/ SRLDC
(f) Observations of the SLDC/SRLDC
The Grid Incidences that had occurred during 15th Nov – 15th Dec 2014 would be discussed in the PCSC meeting.
It is requested that the constituents to send the detailed Report / Analysis of the Grid disturbance/ Major Incidence within 24 hours of the occurrence to SRLDC and SRPC Secretariat.
Agenda for the 39th Protection Coordination Sub Committee Meeting to be held on 30.12.2014 Page 2
4. Submission of Tripping Reports Non-furnishing of Tripping details including Disturbance Recorder/Sequential Event
logger output in compliance of Regulations 5.2 (r) of IEGC – as per the provisions
under clause 1.5 of IEGC 2010 would be discussed in the PCSC.
5. The issue of quantum of df/dt relief in SR The issue would be discussed in the meeting.
6. Status of Pending Protection issues Status of the pending protection recommendations (from 30th PCSC to 37th PCSC)
as circulated vide email dt 01.12.2014 (Annexure II ) may please be sent latest by
22.12.2014.
7. Remedial measures taken for critical tripping events
The constituents are requested to send the remedial measures taken by them for the
tripping events as circulated vide email.
8. Implementation of recommendations of Enquiry Committee (NEW grid disturbance on 30th & 31st July, 2012)
Healthiness of Batteries Healthiness of Batteries Installed at 220 KV and above voltage level Substations (to provide Backup supply to the Relays, RTUs and PLCC Communication Equipment) may be updated on monthly basis since the same has to be communicated to CEA/MOP.
The constituents were requested to submit the healthiness of batteries on monthly basis (i.e. on 7th day of the month).
The following constituents are requested to send the report regularly APGENCO (Hydro), TSGENCO (Hydro), KPTCL, NPCIL (MAPS),
9. Submission of completed dynamic study data In the earlier meetings of PCSC, the forum had decided to collect the Dynamic study
data from the utilities to study the Southern Region system. The dynamic study
format was circulated to the constituents to send the Generator, Excitation system,
Governor, HVDC parameters. The forum opined that the dynamic study details of
the IPPs also are necessary to conduct the study of SR system.
All the SLDCs were requested to direct the embedded IPPs connected at 220 KV
and above voltage level to send the completed dynamic study format to SRPC,
Secretariat.
Agenda for the 39th Protection Coordination Sub Committee Meeting to be held on 30.12.2014 Page 3
It was requested that the dynamic study data in the stipulated format may be sent
to us at the earliest by Email to the following Email IDs.
10. Informing configuration changes to PCSC forum It was agreed in the PCSC forum that if any change in the system configuration ( i.e. addition of Generating Units, Capacitors, Reactors, LILO etc) are to be highlighted and brought to attention of PCSC forum during the PCSC Meetings . This would enable utilities to review their protection settings if any change in the adjoining utilities to have better protection coordination in the Southern Region. All the constituents are requested to send the change in the configuration in their system if any to the PCSC forum on monthly basis.
11. Protection Logic checking of Critical Substations Logic checking of following Critical Substations in the Southern Region had been approved in the SRPC meeting held on 18.05.2013 at Bangalore.
(i) 400 kV Guttur (vi) 400 kV Kurnool (ii) 400 kV Ramagundam (vii) 400 kV Almatti (iii) 400 kV Kalpaka (viii) 220 kV Edamon (iv) 400 kV Nelamangala (ix) 400 kV VTS (v) 400 kV Hoody (x) 400 kV Vemagiri
12. Sending Agenda items for the PCSC meetings
As per the Guidelines of CEA/MOP it had been decided to conduct the PCSC meetings on a monthly basis. It is requested that Agenda Items for the PCSC meetings, if any, may please be sent latest by 5th working day of the month to SRPC Secretariat to compile and circulate the same so as to have fruitful discussions in the PCSC meetings.
13. Next Meeting: Date & Venue The 40th PCSC meeting would be conducted on 29.01.2015 (Thursday) at SRPC Bangalore.
*******
ANNEXURE -I
1
Grid Occurrences to be discussed in 39th PCSC meeting
1. Details of Grid Disturbances:
Sr. No.
Details of Event Date & Time Reason Remarks Category
1 Outage of 220kV Upper sileru power station
23-11-2014 at 17:45 hrs
As per report, LBB of unit-1 operated which resulted in tripping of all elements.
GD-1
2. Details of Grid incidents:
Sr. No.
Details of Event Date &Time Reason Remarks Category
1 Tripping of 400kV Gooty-Somanahalli
22-11-2014 at 16:50 hrs
Line tripped due to suspected PLCC maloperation at Gooty end
2 Tripping of 400/220 kV ICT-3 at TALAGUPPA
23-11-2014 at 17:45 hrs
ICT -3 tripped due to operation of capacitive trip device due to DC fail.
3
Tripping of 400/230 Kv ICT 3 & ICT-1 at ALAMATHY
28-11-2014 at 14:04 hrs & 9-12-2014 at 13:24 hrs
HV Breaker got tripped with Winding Temperature Trip
4 Tripping of 400/220kV ICT-2 at Hoody substation of KPTCL
01-12-2014 at 11:46 hrs
Suspected mal-operation of 220kV side R phase over current relay
5 Tripping of 400 kV Neelamangala-Hoody line -2
04-12-2014 at 16:42 hrs
Line tripped due to relay mal-operation
6 Tripping of 400kV Thiruvelam-Kalivanadapattu line-1&2
10-12-2014 at 1:08 hrs
Over voltage protection operated during B-ph fault in 220 KV Taramani –KVPT line
ANNEXURE -I
2
3. Failure or non-operation of Auto reclose during transient fault
Sr. No. Element Date &Time Reason
1 Tripping of 400kV Talaguppa-Neelamangala
9-12-2014 at 15:03 hrs
Line tripped on R-phase to earth fault. Line did not auto reclose
4. Over voltage tripping
Tripping of 400kV VTPS-Satenapalli line-1&2 at 23:42 hrs on 11-12-2014. Both lines tripped on over voltage and Over voltage protection operated at VTPS end. The reason for simultaneous tripping of both lines needs further investigation and is over voltage grading provided for both the lines.
5. Details of busbar protection not in service/healthy at 220kV and above station to be
furnished by all constituents except KPTCL,TANTRANSCO and APGENCO(Generation/
Thermal).
S.No Meeting No / Index
Meeting S.NO
Details of Event Date Time Reason PCSC Recommendations Utility Responsible
to implement*
Status of Recommendation
Status as on 10.12.2014 Remarks
1 30/I/A 1 RTPS Tripping incidents and the Spl meeting held at RTPS on 13th and 14th March 2014
Mar-14 Spl meeting held at RTPS on 13th and 14th March 2014
The PCSC forum recommended for replacement of existing electromechanical relays with Numerical relays.
KPCL (1) e- Tender folated for the retrofit of existing static relays with Numerical version for lines M.nagar,M.bad,ICT-1 & 2 -Technical Bid opened & price bid yet to be opened.(2) Retrofit of existing bus bar (CAG-34) with numerical version -Budgetetory offers obtained and is under process.
- Pending
2 30/II/1 2 Tripping of 400kV Srisailam-Satenapalli line-1&2
17-02-2014 @ 16:54 & 17:45 hrs
Tripped due to PLCC mal-operation. Status of D.R/ EL at Satenapalli
· TSGENCO informed that the line tripped at Satenapalli end due to receipt of continuous direct trip signal from Srisailam. TSGENCO also informed that the issue has been rectified on subsequent day and no issues were observed. The new relay would be in place within 11/2 months.
TSGENCO Yet to be informed Pending
3 30/II/2 3 Tripping of Udumalpet-Arasur line-2
17-02-2014 @11:57 hrs Line tripped at Udumalpet end only. It was reported that there was auto reclose lock out due to oil leak in breaker. The reason for line tripping due to A/R lock out needs further investigation.
· The PCSC forum requested TANTRANSCO/PGCIL to send the analysis report of the incident at the earliest.
PGCIL informed
PGCIL informed that theincidence has happenedduring Main CBmaintenance. AR scheme hasbeen modified to avoid suchrepeated trippings
Completed
4 30/II/8 4 Tripping of NCTPS-Alamathy-1 & NCTPS-S.V.Chatram-1
26-02-2014 @ 16:25 TANTRANSCO informed that tripping occurred when the Almatti CB was charged at NCTPS end after the maintenance.SRLDC enquired about the commissioning of DR and EL at NCTPS.TANTRANSCO informed that only standalone DR and EL are not yet installed, but relays have built in DR/EL features.TANTRANSCO informed that issue was taken up with the OEM.
TANTRANSCO TANTRASNCO informed that DR and EL yet to be commissioned
Pending
* If any discrepancy It may please brought to the notice of SRPC Secretariat at at the earliest.
1
5 30/II/12 5 Tripping of Raichur-Raichur(PG) line-1&2
05-03-2014 @ 3:39 hrs 400kV Raichur-Raichur(PG) line-1 auto reclosed and tripped. Line-2 tripped from Raichur end only
The PCSC forum requested send the complete tripping analysis report to the PCSC forum
KPCL/SRTS I (PGCIL)
Yet to be informed Pending
6 31/I/2 1 400 kV NEYVELI TS 1 (EXP) - TRICHY
24-Mar-14 at 4:20hrs B phase to earth fault. DT received from Neyveli end
It was suggested to check the protection settings. NLC During the 38th PCSC,NLC informed that by 1st week of December 2014 the Relay would be replaced.
NLC informed that ,It is programmed to change the Main-1 protection relay in the third week of Dec-2014.Protection settings will be rechecked again before commissioning the relay.
Pending
7 31/I/5 2 400 kV HASSAN - UPCL 2 28-Mar-14 at 12:52hrs From D.R of UPCL end it is observed that earth fault protection of line got operated which resulted in tripping of line.
· It was noted that Hassan – UPCL lines tripped on account of back up earth fault protection.UPCL said that more line trippings (usually between 12.00 and 3.00 PM) are due to bamboo/ rubber trees on the right of way. UPCL said that relays would be tested by M/s Alstom shortly.Effective patrolling of the line would be carried out as decided in the meeting held by concerned utility officials. PGCIL suggested that as many trips are attributed to high resistance fault, carrier aided directional scheme is required. UPCL to adopt IDMT characteristics for back up earth fault protection.
UPCL/ KPTCL /PGCIL
Yet to be informed. PGCIL,SRTS II informed that there is no protection issues at Hassan end.
Pending UPCL/ KPTCL
8 31/I/9 3 Tripping of 400kV Vallur-Kalavindapattu line-1&2
13-Apr-14 at 21:06 hrs Failure of B-Phase Current transformer in Vallur Main bay at Kalavindapattu substation which resulted in a bus fault in 400kV bus-2. 400kV Vallur-Kalavindapattu line-2 also tripped during the incident.
PGCIL informed that the tripping occurred due to possible configuration
problem with LBB which is having two features –
common trip (for within bay) and inter-trip (for all bays) and the problem had been
rectified. The complete scheme was also checked subsequently during bay
extension at Kalivanthapattu
9 4 Tripping of 400 K v KLVDPT - VALLUR 1
14-Apr-14 at hrs Line failed due to auto reclose at Vallur end
10 31/II/1 5 400 kV GHANAPUR - MAMIDIPALLY
20-Mar-14 at 15:20 hrs Line tripped at Ghanapur end only on Direct trip receive
The PCSC forum requested TSTRANSCO/PGCIL to check the PLCC system at their respective ends.
TSTRANCO / PGCIL
informed. TSTRANSCO informed that , spurious signal generated in
PLCC panel at 400KV of PGCIL Ghanapur SS end only. No direct trip signal
was sent from 400KV Mamidipally Substation.
Pending (PGCIL)
Completed· PGCIL informed that the tripping occurred due to possible configuration problem with LBB which is having two features – common trip (for within bay) and inter-trip (for all bays) and the problem had been rectified.
TANTRANSCO / PGCIL TANTRANSO informed that Auto reclosure
commissionedfor all feeders on
24.07.2014
2
11 32/I/1 1 Tripping of HVDC Gazuwaka pole-1 and 400kV Jeypore-Gazuwaka line-1
21-04-2014 at 22:40 hrs Mal operation of LBB of Tie breaker (Gazuwaka end) of HVDC Gazuwaka pole-1 and 400kV Jeypore-Gazuwaka line-1 caused the tripping
PGCIL shall submit a detailed report on the tripping incident by 6th
June, 2014.PGCIL Yet to be informed. Pending
12 32/I/3 2 400kV JSW-Guttur line 29-04-2014 at 15:38 hrs Y-phase to earth fault had occurred in line. Reason for non/ unsuccessful auto reclose along with reason for operation of DEFR at Guttur needs further investigation
On account of transient fault, JSW-Guttur line was tripped at Jindal end by distance protection and at Guttur end by DEFR. SRLDC:• Operation of DEFR not desired for transient fault.• Auto reclose (AR) not operating for DEFR is a correct & desired operation.• Un-matching magnitude of fault current of 11KA @ JSW end and 1.6 kA at Guttur end could not be possible. KPCL:• Due to high fault resistance (i.e. 140 ohm primary), the current was less (i.e. 1600A) which could not invoke distance protection (21).• DMT with 1.5 sec (which is more than zone-3 timing) is adopted for DEFR; had IDMT been adopted, it would not have tripped. JSW:• Fault current was 11 kA at Jindal end and distance protection along with auto reclose acted on the JSW-Guttur line.
JSW / KPTCL Yet to be informed. Pending
13 31/I/8 3 Tripping of 400kV Kolar - TVVLM line & 400kV Sriperumbudur-Tiruvalum line
11-Apr-2014 at 20:18
B phase CT failure in 400kV Spdr- Tiruvalum line at Tiruvalum end which resulted in bus fault. Complete outage occurred as lines were connected to one 400kV bus.
· It was noted that Kolar-Sriperumbudur line has LILO at Tiruvalum.SRLDC said that though Tiruvalum- Sriperumbudur tripping was in order, Tiruvalum-Kolar line would not have tripped. The tripping of Tiruvalum-Kolar line was due to the absence of tie-CB at Tiruvalum.It was noted that as of now, Kolar and Nellore (1 & 2) feeders are being operated without tie-CB in the one and half breaker scheme at Tiruvalum.PGCIL informed that tie-CBs for Nellore-1 & 2 lines are being taken into service first time today i.e. 29.04.2014.SRLDC expressed concern over PGCIL operating the 400 kV lines without tie-CBs and not informing Regional Load Dispatcher and stated that the absence of tie-CBs came to its notice in the PCSC meeting only.• It was stated by SRLDC that line operation with single CB is against the protection philosophy. MS i/c, SRPC also expressed his concern over the operation of Line with single CB and not informing the same to SRLDC. The Regional Load Dispatcher would not be kept in dark regarding tie-CB and it is not good for the system. He urged PGCIL to keep SRLDC informed of if any change in the scheme or absence of power system element /equipment.
PGCIL informed. PGCIL informed that Duringthe PCSC meeting, it wasinformed that all theelements were on both mainand tie CBs. In the meeting,it was also informed that it isnot complete outage, otherbus was in service andChittoor I & II and busreactors were in chargedcondition.
Completed
3
14 32/I/7 4 Tripping of 400kV Raichur(PG)-Gooty line-1&2, 400kV Raichur-Raichur(PG) line-1
03-05-2014 at 16:52 hrs Y-B phase fault had occurred in 400kVRaichur-Gooty line-2. Distance protection over-reached at Raichur TPS end for 400kV Raichur-Raichur (PG) line-1 and At Gooty end for 400kV Raichur-Gooty line-1.
SRLDC:•POR scheme is already there.•Time stamps of events in SOE sent to SRLDC is appeared to be incorrect.•SOE of Raichur is not being sent to SRLDC.•Even after 20 days of issuing notice, PGCIL has not yet replied on testing the lines. PGCIL: Gooty 1 & 2 lines were tested and corrected on 11.5.2014 and Raichur lines would also be tested .
PGCIL Yet to be informed. Pending
15 32/I/10 5 Tripping of 400kV Kudankulam-Madurai line
05-05-2014 at 23:47 hrs Y-phase to earth fault had occurred near to Kudankulam. R-and B-Pole of breaker tripped 750ms after tripping of Y-Pole breaker at Madurai. The carrier aided protection at Madurai end and healthiness of PLCC link needs to be tested
Recommendations NPCIL is requested to inform the PCSC forum regarding the implementation schedule of auto reclose feautre at Rajasthan Atomic Power Plant and KKNPP.
NPCIL PGCIL informed that the complete AR scheme was checked during next opportunity shut down and found working satisfactorily.
Kaiga GS response: The matter of implementation of Auto Reclose feature for 400 kV transmission lines at KGS-3&4 is referred to NPCIL HQ. Based on its satisfactory performance at RAPS-5&6 units, consent will be given by HQ for its implementation in KGS-34 AND ACCORDINGLY SCHEDULE WILL BE PROVIDED FOR ITS IMPLEMETATION.
Pending
16 32/II/6 6 400kV Ramagundam-Chandrapur line – 1
28-04-2014 at 14:46 hrs R-phase to earth fault had occurred in line. Line did not auto reclose
NTPC:•Auto reclose feature is not in service on Ramagundam – Chandrapur line due HVDC back-to-back link at Chandrapur. It was informed that HVDC link faces problem if there is auto-reclose feature. •It was informed that nowhere in the country, 3-phase auto reclose is implemented for the lines at generating station. •NTPC informed that sending DT for the earth fault at Chandrapur end is not a correct operation. PGCIL:•Problematic protection coupler is to be replaced for the line.•3-phase auto reclose feature is implemented on the Gazuwaka-Jeypore which is having HVDC back-to-back at Gazuwaka. Synchro check is done and 1-phase auto reclose is converted into 3-phase auto reclose. SRLDC:•3-phase auto reclose feature implemented on Gazuwaka-Jeypore line is not known to SRLDC and it is not clear under what conditions it was approved. However, SRLDC recommends 1-phase auto reclose. MS i/c:•PGCIL should come back with a plan for implementing auto reclose feature on Ramagundam – Chandrapur line.
PGCIL / NTPC Yet to be informed. Pending
4
17 32/II/7 7 400kVGuttur-Narendra line-2
30-04-2014 at 20:19 hrs R-phase to ground fault. Line auto reclosed at Narendra end but failed to reclose at Guttur end
KPTCL: • Bays are maintained by PGCIL at Narendra.PGCIL• Relays were checked individually but the scheme of auto reclose is not yet checked. It will be done after taking the line shutdown.
PGCIL / KPTCL informed. PGCIL informed that CB pressure switch problem observed and the same was rectified.
Completed
· 22-05-2014 at 15:02 hrs
07-06-2014 at 19:44hrs
19 33/I/4 2 Tripping of 400kV Nellore pooling station-MEPL line
23-05-2014 at 14:11 hrs Line tripped at Nellore pooling end only due to direct trip receive from MEPL end.
FIR: At NPS end, line tripped after receiving DT. At MEPL end, there was DC earth fault.
Deliberations:The issue was noted.
PGCIL /MEPL Yet to be informed. Pending
20 33/I/5 3 Tripping of 400kV Nellore-Nellore pooling line-1&2 and tripping of 400kV Nellore-SEPL line
23-05-14 at 17:01hrs & 17:03 hrs
400kV Nellore-Nellore polling line-1&2 tripped on transient faults. 400kV Nellore-SEPL line got tripped on operation of directional earth fault protection.
Recommendations:The PCSC forum requested PGCIL to submit the detailed trip
analysis report for all the three occasions (16:59, 17:01 and 17:03 hrs) to SRLDC and SRPC.
SEPL / PGCIL Yet to be informed. Pending
27-05-14 at 14:26 hrs &
29-05-2014 at 17:01 hrs
22 33/I/8 5 Multiple element tripping and generation loss at 400kV Neyveli TS-2 station
05-06-14 at 19:10 hrs Lighting cable of switchyard gantry tower got broken and fell over 400kV bus-1 resulting into a bus fault on 400kV bus-1 at Neyveli TS2
SRPC:• Due to generating units tripping at NLC, a problem of low voltage conditions develop at Kayathar area leading to wind power withdrawal from the grid. As this withdrawal is having impact on the inter-regional tie-lines, the issue should be resolved as quickly as possible.
NLC informed. NLC informed that all unused lighting cables hanging from various towers were removed by availing LC on Bus and feeders.
All corrective and preventive actions have been taken to ensure non-occurrence of such trippings.
Completed
23 33/I/9 6 Tripping of 400kV Karaikudi-Madurai line
05-06-14 at 20:20 hrs Line tripped at Madurai end only and was holding from Karaikudi end. It was reported in FIR that line distance protection over reached
PGCIL: • EPAC relay mal-operated while charging the Trichy - Karaikudi line, hence the tripping of the line. The file from relay was downloaded and replayed, but it did not trip the relay.
PGCIL informed. EPAC relay mal-operation observed. The relay was replaced by 7SA522 relay subsequently.
Completed
24 33/II/1 7 400kV Hassan-UPCL line-2 19-05-2014 at 16:06 hrs Transient fault had occurred in R-phase and line auto reclosed from Hassan end
• It was noted that distance protection of Main-I sensed R-Y fault and Main-II sensed R-N fault (2 KA current).RecommendationThe PCSC forum requested KPTCL /UPCL to check the both the
relays and CTs for variation in sensing and operation.
UPCL / PGCIL / KPTCL
Yet to be informed. PGCIL informed that no problem at their end
Pending (UPCL / KPTCL )
18
21
PGCIL
33/I/6 4 Tripping of 765kV Raichur-Sholapur line
Line tripped due to transient faults. Line did not try to auto reclose.
Deliberations:The issue was noted.
PGCIL
33/I/3 1 Tripping of 400kV Jeypore-Gajuwaka line-1&2 and Pole 1&2 at HVDC Back to Back station at Gazuwaka
Line-2 tripped on R-N fault. Line-1 tripped from Gajuwaka end only. HVDC tripped due to loss of East bus voltage.RecommendationsThe PCSC forum recommended PGCIL to submit the following to
SRLDC and SRPC:• DR of Jeypore - Gajuwaka lines tripping on 22.5.2014 and 7.6.2014• Action taken for testing the relay or its replacement.• Complete analysis of the faults and rectification/remedial action taken to avert similar occurrence in the HVDC Back to Back station.
Yet to be informed.
Yet to be informed. Pending
Pending
5
25 33/II/2 8 400kV Ramagundam-Hyderabad line-4
19-05-2014 at 21:00 hrs Transient fault had occurred in R-phase. Line auto reclosed at Ramagundam and failed to reclose at Hyderabad due to direct trip receive.
• NTPC: no PLCC counter has gone up (incremented) at Ramagundam• PGCIL: DT was received from Ramagundam, and hence the tripping of the line.RecommendationThe PCSC forum requested for joint checking of PLCC system by
NTPC and SRTS I, PGCIL .The report to be sent to PCSC forum at the earliest.
NTPC , PGCIL Yet to be informed. Pending
22-05-14 at 19:32 hrs
23-05-2014 at 16:56 hrs
27 33/II/5 10 400kV VTPS – Malkaram-1 26-05-2014 at 02:14 hrs 400kV VTPS-Malkaram line-1 tripped on a y-Phase to ground fault. Line auto-reclosed at Malkaram end
RecommendationPCSC forum requested SLDC of Andhra Pradesh / Telangana to take
up the issue with the generator ( VTPS) for attending/ correcting the problem.
TSGENCO Yet to be informed Pending
28 33/II/6 11 400kV Khammam-Mamidipally line-1
26-05-14 at 3:31 hrs Line tripped on a R phase to earth fault . Line did not auto reclose and Y- and B pole of breakers opened 400 ms after opening of R-pole
It was informed that Stage-2 O/V setting is 140 % @ 100 ms. During the process of auto-reclosing, O/V occurred at the dead time and the line tripped.
PGCIL / TSTRANSCO
informed High voltage incident occurred after 300ms of the occurance of fault causing operation of Stage-II O/V relay at 400KV Mamidipally SS of TSTRANSCO. Trip command was extended to Y & B phases instantaneously instead of 100ms due to timer problem. The defective timer has been replaced. [Report Enclosed]
Completed
29 33/II/10 12 400 kV RAMAGUNDAM - WARANGAL
13-06-14 at 16:38 hrs B-phase to ground fault had occurred. Line failed to reclose from Ramagundam end.
NTPC:Main-I distance protection relay sensed single phase fault and Main-II relay (RAZFE-ABB) sensed R-Y (line to line) fault which got priority over single phase fault and the line was given 3-phase tripping.
NTPC , PGCIL , APTRANSCO
Yet to be informed Pending
30 34/I/3 1 Tripping of HVDC Bhadravati Pole-1&2
09-07-2014 at 3:50 hrs and 5:04 hrs
As reported pole-1&2 tripped due to auxiliary supply failure.
Recommendations: The PCSC forum recommended PGCIL, SRTS-I take up the issue
with WRTS to submit the report as per IEGC guidelines. SRLDC is also requested to send a letter to WRLDC to submit the
reports to SR also. Based on the SRTS/SRLDC correspondences, SRPC would take it
up with WR and PGCIL if the issue is not getting resolved. Complete analysis of the faults and rectification/remedial action
taken to avert similar occurrence in the HVDC Back to Back station shall be submitted.
PGCIL Yet to be informed Pending
KPCLB phase to ground fault had occurred in line and line auto reclosed at Hiriyur end but failed to reclose at BTPS end.
• KPCL: A/R is not yet enabled at Raichur plant.RecommendationThe PCSC forum requested KPCL to enable the A/R feature at RTPS
end before next PCSC meeting (i.e. 31st July, 2014.
400kV Hiriyur-BTPS line-233/II/3 926 A/R at BTPS end will be danbled during November 2014 End and needs LC
Pending
6
31 34/I/6 2 400/220 kV ICT-1 & 2 at MUNIRABAD
16-07-2014 at 2:31 hrs As reported directional over current relay of ICT’s operated due to snapping of line jumper in 220kV Lingapur line.
Recommendations: Bus bar protection shall be provided by asset owner ( i.e KPTCL) .
Settings for main distance protection & Overcurrent protection shall be examined and reviewed. Time synchronization of the Substation shall be ensured. Correct DR shall be submitted to the SRLDC for trip analysis.
KPTCL Management approval is obtained for taking up the work of providing bus bar protection to 220kV buses at Guddadahally (Munirabad) Sub Station along with replacement of 3 core/age old CTs of 220kV bays belong to KPTCL. Finalization of scheme/specification is under process.
Pending
32 34/I/7 3 HVDC BHADRAVATHI POLE 2
18-07-2014 at 20:10 hrs As reported pole-2 tripped due on 5th harmonic alarm.
Recommendation : Complete analysis of the faults and rectification/remedial action
taken to avert similar occurrence in the HVDC Back to Back station shall be submitted. The PCSC forum recommended PGCIL, SRTS-I take up the issue
with WRTS to submit the report as per IEGC guidelines. SRLDC is also requested to send a letter to WRLDC to submit the reports to SR also. Based on the SRTS/SRLDC correspondences, SRPC would take it up with WR and PGCIL if the issue is not getting resolved.
PGCIL Yet to be informed Pending
33 34/II/2 4 400kV Kurnool-Srisailam line 21-06-2014 at 7:55 Recommendation : Relays with DR feature shall be installed within two months time;
since there is a bus coupler at Srisailam, it could be done in a phased manner.
APTRANSCO One Number of Numerical Distance relay was allotted to replace the static relay on Srisailam feeder at Kurnool as a remedy.Relay yet to b commissioned.
APTRANSCO informed that the isue was discussed in the 38th PCSC meeting about the remedial measures taken and committee recommended to replace the relay with in 3 to 4 months
Pending
34 34/I/3 5 400kv Kaiga-Guttur line -2 22-06-2014 at 3:10 D.R/ E.L of Guttur station not furnished
Recommendation :
KPTCL is requested to wire final trip relay contact to DR.
KPTCL Yet to be informed Pending
35 34/I/5 6 400kV Srisailam-Mamidapalli line-2
10-07-2014 at 23:54 D.R/ E.L of Srisailam station were not furnished.Deliberation:Discussed in S.No. 4
TSGENCO Yet to be informed Pending
36 34/I/7 7 400kV Kalpaka-Vemagiri line-2
12-07-2014 at 02:50 Vemagiri end D.R/E.L not furnished. APTRANSCO APTRANSCO informed that EL was furnished.Extraction of D.R from REL 316 was not possible. The same is informed to the company service personnel.
Completed
37 34/III/1 8 400kV Raichur-BTPS line 26-06-2014 at 1:25 hrs Transient fault in R-phase. Line did not auto reclose
Recommendation :
A/R at BTPS end to be made operational within one month
KPCL A/R at BTPS end will be danbled during November, 2014End and needs LC
Pending
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38 34/III/3 9 400kV Vallur-Kalivandapattu line-1
10-07-2014 at 19:56 hrs& 20:21 hrs
Fault in B-phase. Line did not auto reclose.
PGCIL: • At 19:56 hrs it was 2nd fault within a short time.• At 20:21 hrs D/T was received and while charging it tripped.
PGCIL informed At 19:56hrs, the occurrence of fault is during reclaim time and hence, AR lock out operated. And at 20:21hrs the fault was persisting during energisation and hence, it did not auto reclose.
completed
39 34/IV/a 10 UPCL agenda regarding tripping of Hassan – UPCL – 2 line ( tripped 12 times )
Jul-14 Recommendation :
Constituents were suggested to follow Patrolling Guidelines finalized for SR. The guidelines had been informed to Hon’ble Commission . The Guidelines were available on SRPC website.
KPTCL Yet to be informed Pending
40 35/I/2 1 220 kV KAIGA – KODASALLY an 220kV Kodasalli -Nagjheri line
19-07-2014 at 12:22 hrs 220kV Kaiga-Kodasalli line tripped on operation of over current protection.
It was also reported that 220 kV Kodasalli-Nagjheri line had tripped due to fault.
From D.R of KAIGA station it was observed that the fault persisted for around 340 ms.
Recommendations:
a) KPCL was requested to send the detailed tripping analysis report to SRLDC and SRPC.b) The utilities are requested to send the single Line Diagram / Lay out plan of the affected Substation/ System.c) KPTCL /KPCL to review the SOTF settings for Kodasalli – Nagjheri lines.d) Resistive reach of the distance relay shall be reviewed to take care of the high resistance fault.
KPCL (i) As per the proceeds of the PSAG-10 relays will be replaced.Temporarily aranged.(ii) SOTF setting already reviewed.(iii) Resistive reach is calculated and will be uploaded in the seond week of Dec.2014.
Pending
41 35/I/5 2 400kV KTPS-Khammam line-1&2, KTPS unit-11 tripped
31-07-2014 at 20:31 hrs CT blast at KTPS SRPC:TSGENCO /PGCIL was requested to correct the Time drift in the
KTPS-Khammam corridor at the earliest and the same may be informed to the SRPC Secretariat on or before the next PCSC meeting.
TSGENCO / PGCIL
Yet to be informed Pending
42 35/I/8 3 400/220kV ICT-2 at Vijayawada
09-08-2014 at 13:53 hrs ICT tripped due to downstream fault in 220kV system.
Recommendation :• SRTS- I (PGCIL) and APTRANSCO were requested to check up the DT signal settings (both at initiation and reception points) in their respective substations and cross check their system. The details shall be sent to SRPC Secretariat on or before the next PCSC meeting.
APTRANSCO / PGCIL
APTRANCO informed that they had checked all settings and wirings. The protection settings at APTRANSCO end are in order.
Pending (PGCIL)
43 35/II/1 4 400 kV KURNOOL - SRISAILAM
29-07-2014 at 20:50hrs Y-phase to earth fault. Line did not auto reclose
• Old static relay would be replaced by numerical relay.• APTRANSCO informed the forum that the static relay would be replaced with the Numerical realy with in 3 month’s time.
APTRANSCO APTRANSCO informed that one number of Numerical distance relay was allotted to replace the static relay on Srisailam feeder at Kurnool Substation as an inteirm measure.Rely yet to be commissioned.
Discussed in the 38th PCSC meeting about the remedial measures taken and committee recommended to replace the relay with in 3 to 4 months
Pending
8
44 36/I/3 1 400 kV Khammam-Kalpakka line- 1
23-08-2014 at 18:24 hrs Line tripped at Khammam end only on operation of distance Protection and was holding from Kalpaka end. The reason for operation of distance protection needs to be furnished
Recommendations:
a. Indication of the SOTF operation and Open jumper detection should be furnished. b. PGCIL was recommended to check the fuse failure logic and the relay settings at their end.c. Distance protection scheme should be investigated.PGCIL was requested to refer the case to OEM for possible remedy.
PGCIL/ APTRANSCO
APTRANSCO informed that the Line is inservice from Kalpaka. There is no issue from APTRASNCO
Pending (PGCIL)
45 36/I/5 2 ICT -1 & 2 at Guttur Substation
26-08-2014 at 13:44 hrs ICT’s tripped on operation of Earth fault relay. Triggering incident was failure of Jumper in 220kV Guttur-Neelagunda line.
Recommendations:
a. Protection System Analysis Group (PSAG-8) was held on 25 & 26.09.2014 at Guttur (400 KV, KPTCL SS ) to discuss the frequent tripping of 400KV Kaiga-Guttur lines on account of over-voltage and transient faults .The Minutes of the PSAG-8 Meeting is enclosed herewith as Annexure – V.b. KPTCL was requested to send the steps/action taken to implement the recommendations of the PSAG-8 meeting held at Guttur on 25&26.09.2014 to the PCSC.
KPTCL Pointwise compliance on PSAG-8 MOM is furnished to SRPC
partially completed and partly Pending
46 36/I/6 3 765kV Raichur-Kurnool 27-08-2015 at 10:15 hrs line tripped at Kurnool end only and was holding from Raichur end.Distance protection Zone-4 got operated while replacing VT fuse and tripped the breaker at Kurnool end.
Recommendations:The PCSC forum requested PGCIL, SRTS-I to check / review the CVT fuse alarm logic
PGCIL Yet to be informed Pending
47 36/I/7 4 765kV Raichur-Kurnool 30-08-2014 at 17:52 hrs Relay Mal-operation at Raichur End Recommendations:
The PCSC forum requested PGCIL, SRTS I to check / review the CVT fuse alarm logic.
PGCIL Yet to be informed Pending
48 36/I/8 5 Multiple Tripping at 400 kV Guttur station
12-09-2014 at 12:22 hrs 400kV Kaiga-I, Hiryur-I, Narendra-I & ICT-I tripped at Guttur station due to operation of bus bar protection of 400kV Bus-1 at Guttur. It was reported that the LBB protection acted due to wrong configuration of distance relay
Recommendations:
a. Protection System Analysis Group (PSAG-8) was held on 25& 26.09.2014 at Guttur (400 KV, KPTCL SS ) to discuss the frequent tripping of 400KV Kaiga-Guttur lines on account of over-voltage and transient faults .The Minutes of the PSAG-8 Meeting is enclosed herewith as Annexure – V.b. KPTCL was requested to steps/action taken to implement the recommendations of the PSAG-8 meeting held at Guttur on 25&26.09.2014 to the PCSC.
KPTCL Pointwise compliance on PSAG-8 MOM is furnished to SRPC
partly completed and partly Pending
49 36/I/9 6 220kV Srisailam right bank station
03-09-2014 at 10:41 hrs It was reported that trip wire to circuit breaker of 220kV Dindi-2 was open which resulted in operation of LBB protection and tripping of all elements connected to 220kV Bus-2.
Deliberation & Recommendation: a. The issue was discussed in the Protection System Analysis Group (PSAG-9) meeting held at Srisailam Right Bank Power House (SRBPH) on 14& 15.10.2014 .b. APGENCO was requested to inform the steps /action taken to implement the PSAG-9 meeting recommendations during the next PCSC.
APGENCO Pointwise compliance on PSAG-9 MOM is furnished to SRPC
partly completed and partly Pending
50 36/I/10 7 220kV Srisailam right bank station
03-09-2014 at 16:09 Mal-operation of LBB relay which resulted in tripping of all elements connected to 220kV Bus-1
Deliberation & Recommendation:
a. The issue was discussed in the Protection System Analysis Group (PSAG-9) held at Srisailam Right Bank Power House (SRBPH) on 14& 15.10.2014 .b. APGENCO was requested to inform the steps /action taken to implement the PSAG-9 meeting recommendations during the next PCSC.
APGENCO Pointwise compliance on PSAG-9 MOM is furnished to SRPC
partly completed and partly Pending
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51 36/II/1 8 400kV Munirabad - Guttur 17-08-2014 at 4:05 hrs R-phase to earth fault. Line did not auto reclose at Munirabad end
PGCIL: Problem could be at line CB side.SRLDC: A/R scheme needs checking.
KPTCL / PGCIL Yet to be informed Pending
52 36/II/2 9 400kV Madurai-Costal Energy 21-08-2014 at 14:50 B-phase to earth fault. Line did not auto reclose at Coastal Energy end.
SRLDC:There was an earth fault on B-phase and subsequently A/R scheme has been rectified.
TANTRANSCO / Coastal Energy
Yet to be informed Pending (Coastal Energy / TANTRANSCO(SLDC))
53 36/II/3 10 400kV JSW-Guttur line 21-08-2014 at 23:32 hrs R-phase to earth fault. Line did not auto reclose
• Decapping of insulator resulted in persisting fault that led to the tripping of the line.
JSW / KPTCL Yet to be informed Pending
54 36/II/5 11 400kV Ramagundam-Chandrapur line – 1
25-08-2014 at 17:52hrs Line tripped on B-phase to earth fault. As per FIR of chandrapur station, line did not auto reclose as auto reclose is kept out of service.
Recommendation:PGCIL to take up the issue with OEM in this regard.
PGCIL Yet to be informed Pending
03-09-2014 at 12:46hrs
04-09-2014 at 12:52 hrs
56 36/II/8 13 400kV Raichur-Munirabad line 07-09-2014 at 00:03hrs B-phase to earth fault had occurred in line. Line auto reclosed at Munirabad end and failed to reclose at Raichur end
KPTCL: PD (pole discrepancy) time delay would be changed.
PGCIL / KPTCL Yet to be informed Pending
57 36/II/9 14 400kV Arasur-Mettur Line I 29-09-2014 at 21:10 hrs Recommendation:Mettur S/s to Enable A/R Scheme.
TANTRANSCO During the 38th PCSC meeting ,TANTRANSCO informed that the Auto Reclosing facility would be enabled within 15 days.
Pending
36/II/7 12 400kV VTPS-Malkaram line 55 TSTRANSCO informed that from their end DR & EL reports were uploaded with in 24 hours from Malkraram end.
R-phase to earth fault. line did not auto reclose
APGENCO: • DR and EL were not uploaded (at SRLDC website) for this event, as the user login details were not known. The same would be obtained from SRLDC
TSTRANSCO / APGENCO
Pending (APGENCO)
10
58 37/I/1 1 Tripping of 400/220kV ICT-1 & ICT-2 at 400kV Warangal substation
18-09-2014 at 21:01 hrs ICT’s tripped due to operation of Directional Earth Fault relays on 400 KV side of ICT 1 &2. It was informed that fault had occurred in downstream 220kV system. From D.R of ICT’s fault ampere of 2kA and 2.7kA in R phase was observed for ICT-1&2 respectively. The tripping need further analysis as the fault current was not high to operate the High set of earth fault relay and there was no delayed clearance of fault in 220kV system.
Recommendations:PGCIL is requested to send trip analysis indicating the cause of high set operation despite not very high fault current.
PGCIL Yet to be informed Pending
59 37/I/2 2 Tripping of 400kV Bus-1 and 400kV Ramagundam-Nagarjunasagar line
19-09-2014 at 12:44 hrs LBB protection of 400kV Ramagundam-N’sagar line had mal-operated due to spurious initiation from 86 trip relay which caused tripping of 400kV Ramagundam-N’sagar line and direct trip to remote end. Along with this LBB
Recommendations:NTPC is requested to explore the possibility of including re-trip feature in the LBB relay before actual LBB initiation.
Yet to be informed Pending
60 37/I/3 3 Tripping of 400kV Raichur-Mahboobnagar line
20-09-2014 at 22:34 hrs line tripped at Raichur end only due to operation of carrier lock out relay
Recommendations:KPCL is requested to expedite the process of installing adequate DC batteries for PLCC system.
KPCL Yet to be informed Pending
61 37/I/4 4 765/400 kV ICT-3 at NPS 22-09-2014 at 7:48 hrs FIR, D.R, E.L not submitted. As per verbal information L.A failure had caused tripping of ICT
Recommendations:a. As despite normal voltage at 400 kV bus, new LA and bus reactors in service, the failure of LA shall be investigated by PGCIL and a report shall be sent to the PCSC forum.b. Efforts shall be made to retrieve the DR data pertaining to the differential operation and the retrieved data shall be sent to PCSC forum. c. Equipment failure report for 400 kV LA shall be sent to SETD division of CEA, New Delhi.
PGCIL / NPS Yet to be informed Pending
62 37/I/5 5 220kV Ambewadi-Ponda line 25-09-2014 at 12:54 hrs As per FIR line was hand tripped due to 220/110kV Bus dead. Reason for bus de-energization may be furnished to PSC
Recommendations:a. A trip analysis report shall be with the corrective actions for the following issues shall be sent to PCSC forum.b. Measures for preventing Ambewadi – Nagjheri line -1 opening in case of fault on the Ambewadi – Nagjheri line -2 and vice versa.
KPTCL Yet to be informed Pending
11
63 37/I/6 6 Tripping of 400KV Hassan-UPCL line-2
25-09-2014 at 16:16 hrs High resistance fault as the fault ampere was very less i.e., 0.6kA at Hassan end and nearly 0.9kA at UPCL end. Back up earth fault protection had operated at Hassan. At UPCL end the high resistance fault got converted into a R ph-B-ph fault which resulted in operation of distance protection Zone-1. The reason for non-picking up of Back up earth fault at UPCL needs investigation.
Recommendations:a. At UPCL end, unused zones of distance protection (probably zone 5 to 8) shall be disabled.b. At UPCL end, time synchronization between main-1 and main-2 relays shall be ensured.c. UPCL shall ensure time synchronization with Hassan substation.d. Reasons for non operation of back up protection at UPCL for high resistance fault is to be submitted.e. Reasons for not sending DT to UPCL by Hassan end is to be submitted.f. Settings of UPCL are to be reviewed and informed to PCSC forum.
UPCL / KPTCL / PGCIL
Yet to be informed PGCIL informed that requirement of sending DT during DEF protection is not as per basic protection philosophy.
Pending (UPCL/ KPTCL)
64 37/I/7 7 Tripping of 400/220 kV ICT-1 AT BTPS
27-09-2014 at 16:22hrs FIR, D.R, E.L not submitted. As per verbal information due to problem in 220kVside
Recommendations:KPCL is requested to collect DL, EL and trip analysis and submit to PCSC forum.
KPCL Yet to be informed Pending
65 37/I/9 9 Tripping of 400/220kV ICT-1&2 at UPCL
04-10-2014 at 12:16 hrs ICT-1&2 tripped during transient fault in R-phase in 400kV Hassan-UPCL line-1
Recommendations:To avoid tripping of ICTs for line fault, UPCL is requested to review the settings of ICT’s SEF relay and consider IDMT setting instead of existing Definite Time setting.
UPCL Yet to be informed Pending
37/I/10 10 Tripping of 400kV NPS-MEPL line
08-10-2014 at 7:04 hrs Line tripped due to DT receive from MEPL
Recommendations:a. The exact reason for receipt of DT signal at NPS end from MEPL end has to be found out and corrective measures need to be taken up by both MEPL and NPS to avoid its recurrence.b. The forum decided to invite MEPL and SEPL whenever there is a tripping involving their power stations.
MEPL / PGCIL Yet to be informed Pending
66 37/I/11 11 Tripping of 400 kV NPS - TPCIL 2
08-10-2014 at 7:04 hrs Line tripped at NPS end only. As per FIR, R-B phase fault had occurred in 400kV NPS-TPCIL line-1
Recommendations:a. At NPS end, corrective measures shall be taken to avoid tripping of line-2 CB for the fault on line-1 and vice versa.b. Both NPS and TPCL shall ensure time synchronization with each other.c. Status of recommendations of PSAG-1 meeting held at NPS (on 24th July, 2013 ) shall be submitted.
TPCIL / PGCIL Yet to be informed Pending
67 37/I/13 12 Tripping of 400kV Raichur-Munirabad line
09-10-2014 at 14:03 hrs line tripped due to operation of carrier lock out relay
Recommendations:KPCL is requested to expedite the process of installing adequate DC batteries for PLCC system.
KPCL Yet to be informed Pending
68 37/II/3 13 400kV Mettur-Arasur line-1 29-09-2014 at 21:10 hrs line tripped due to Y-Phase to earth fault. Line did not auto reclose as Auto reclose scheme is kept in non-auto mode.
· A/R is not in service. TANTRANSCO Yet to be informed Pending
69 37/II/5 14 400 kV NEYVELI TS 2 (EXP) - PUGALUR
05-10-2014 at 21:47hrs Y-phase to earth fault had occurred in line. Line did not auto reclose. DT was received from Neyveli TS2(EXP) end
Have to submit remedial measures NLC informed NLC informed that ,It is programmed to test the Main-2 relay within 31-12-14, for further processing.
Pending
70 37/III/2 15 400kV Srisailam-Satenapalli-2 19-09-2014 at 20:53 hrs · D.R of Srisailam end not submitted TSGENCO Yet to be informed Pending
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