Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 1
SOUTHERN REGIONAL POWER COMMITTEE BENGALURU
Minutes of the 70th Meeting of Protection Coordination Sub-Committee (PCSC – 70) of SRPC held on 18th December, 2017
1. Introduction
The 70th meeting of Protection Coordination Sub-Committee (PCSC-70) of SRPC was held on 18th December, 2017 at SRPC Secretariat, Bengaluru. The list of participants is enclosed at Annexure-I. Member Secretary (MS), SRPC welcomed Members and Participants to the meeting and briefed them on the following points: Congratulated all Constituents for ensuring minimal trippings in the months of October-November,
2017, and hoped that the same level of gird-discipline is maintained in future also.
Apprised Members that setting up of Data Centre to house various Servers that would be supplied as part of PMS project had been completed with contribution from SR-Constituents, and stated that its operation would shortly commence after completion of the on-going installation & commissioning activities of various servers and associated soft-wares. In this regard, he requested Puducherry ED to make the payment due from them at an early date. He also stated that during data-collection from various TamilNadu stations by PRDC, it was noticed that some stations had furnished only part-data. Since complete protection data is essential to build envisaged protection database, he requested all concerned utilities to cooperate with PRDC in furnishing all pending data as per the stipulated formats.
Informed Constituents that as proposed in the last meeting, a review meeting on compliance of pending PCSC recommendations would be conducted after completion of regular business of PCSC meeting, and requested all members to present in detail the actionable measures proposed by them to attend the pending recommendations applicable to their systems.
Brought Members’ attention to completion of revised time-lines stipulated by Hon’ble CERC for various SR-Constituents for attending their respective pending Protection Audit Remarks (PAR). Expressing concern at the seemingly large percentage of pending PAR works by some Constituents, he stated that urgent action needed to be taken by their Managements to ensure things would not slip further. In this regard, he also requested Constituents who are likely to take more time for attending their respective PAR works to approach Hon’ble CERC for obtaining required time-extensions.
2. Confirmation of the Minutes of the 69th meeting of PCSC held on 23rd November, 2017
The minutes of the 69th meeting of PCSC had been circulated vide SRPC letter No. SRPC/SE-III/ PCSC-69/ 2017/ 7306 – 41 dated 13.12.2017. Since no comments had been received from any of the Constituents, the minutes of the 69th Meeting of PCSC were confirmed.
Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 2
3. Details of Grid Disturbances (GD’s), Grid Incidents (GI’s), and Line Trippings due to Auto-
Reclose (A/R) failure/ non-operation & PLCC mal-operation
The trippings due to GD’s, GI’s, A/R failure/ non-operation, and PLCC mal-operation that had occurred
during November, 2017 were discussed in the Meeting. The deliberations and recommendations of the PCSC Forum are enclosed at Annexure–II for further needful action. The details of the tripping events including relevant PMU plots presented by SRLDC in the meeting are also enclosed at Annexure-V for kind reference.
4. Status of pending PCSC Recommendations (P-REC)
The status of implementation of pending PCSC recommendations was discussed in the meeting. The
updated status of the same as on 05.01.2018 is enclosed at Annexure–III. The Constituents were asked to take steps to comply with the same, and requested to submit the status of their compliance latest by 25.01.2018.
5. Remedial measures/ Action taken for the tripping incidents of the transmission elements
under forced outage (PRM)
The tripping incidents of the transmission elements under forced outage for which the remedial action
taken had not been furnished were discussed in the meeting. The Constituents were asked to kindly furnish specific remedial measures/ action taken covering one or the other items from the following indicative list in time so as to forward the same to Central Electricity Authority:
Brief details of line patrolling carried out (with tower location)
Brief details of RoW maintenance (by proper Tree-cutting) resorted to
De-capped insulators replacement
DC earth fault removal
PLCC cards replacement
Relay settings modification
Steps taken to put A/R or CB into service after they have been locked-out
Faulty equipment replacement
Reference to OEM in case of equipment failure
Brief Details of tests carried out to ascertain the healthiness of various equipment (Power Transformer/ Reactors/ Surge Arrestors/ Circuit Breakers/ CT's/ PT's/CVT's) like Insulation Resistance (IR) test, Winding Resistance test, Capacitance test, Tan delta test, DGA test, Leakage current test, CRM/ DCRM test, etc.
Any other appropriate remedial measure
The updated list of PRM as on 05.01.2018 is enclosed at Annexure-IV.
6. Certificate for Healthiness of Batteries
As per the MoP/ CEA direction given in pursuant to recommendations of the Enquiry Committee (NEW Grid Disturbance on 30th & 31st July, 2012), RPC’s are required to obtain from their respective Constituents a monthly certificate for healthiness of batteries installed at 220 KV & above voltage level Substations (for power supply to Relays, RTUs and PLCC equipment) and furnish the same to CEA/ MoP.
Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 3
With reference to above, the Constituents had been requested to submit the certificate on healthiness of batteries on monthly basis (i.e. status for a month shall be sent by the 7th day of the following month) to SRPC as per the format given below:
Sl. No.
Station Application Battery Battery Charger Remarks
Station Name
Code Type
(PS/ SS)
Protection/
Communication
Details Status (Healthy/ Unhealthy)
Details Status (Healthy/ Unhealthy)
1 Station-A Protection (Bank-1)
Protection (Bank-2)
Communication (Bank-1)
Communication (Bank-2)
2 Station-B …
… … …
Note: 1. Code is the short name of the Station 2. PS – Power Station; SS - Substation
The sought status for the month of November, 2017 had not been received from the following SR-Constituents:
KSEBL, Puducherry ED & NTECL
7. Implementation Status of Protection Management System (PMS)
Implementation status of PMS project for the period 23.11.2017 – 17.12.2017 is given below:
Conduction of PSCT Training Programme by PRDC to the following Constituents:
Training Schedule Location Utilities Remarks
20.11.2017 – 24.11.2017
KPTCL HQ, Bengaluru
KPCL & KPTCL Completed
27.11.2017-01.12.2017
TSTRANSCO HQ Hyderabad
TSGENCO TSTRANSCO PGCIL(SR-I)
Completed
04.12.2017-08.12.2017 APTRANSCO HQ Vijayawada
APGENCO APTRANSCO
Completed
11.12.2017-15.12.2017 SLDC, Kalamassery
KSEBL Completed
Protection Data Collection from all Stations/ Substations connected to the grid at 220 kV &
above voltage level in the state of TamilNdu is under final-leg of completion.
Data cleansing and Protection SLD preparation of the stations for which data had been
collected is under progress.
Building of the network data for operational load flow and fault calculations is under progress.
Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 4
Set-up of Data Centre to house PMS Servers was completed. Installation & configuration of
various PMS Servers and associated soft-wares is under progress.
8. Network Configuration Changes
As per the information furnished by SR-Constituents to the OCC forum in their 138th meeting (held on
11.12.2017; Minutes circulated on 29.12.2017), it is formed that the following network configuration changes (additions/ deletions/ modifications of transmission elements) took place in the southern grid during November, 2017.
220 kV D/C line from Palmaneru to Madanapalli in Chittoor district of 116 Ckm was commissioned on 10.11.2017 by APTRANSCO
220 kV 2nd circuit from Bommur to LILO point and LILO to Bavojipeta (Korukonda) Switching Station in East Godavari District of 34 Ckm was commissioned on 17.11.2017
220 kV D/C line from Bavojipeta to Purushothapatnam in East Godavari district of 21 Ckm was commissioned on 17.11.2017 by APTRANSCO
220 kV D/C line from Bavojipeta to Ramavaram in East Godavari district of 29 Ckm was commissioned on 17.11.2017 by APTRANSCO
220 kV Switching Station at Bavojipeta (Verukonda) in East Godavari Dist was commissioned on 17.11.2017 by APTRANSCO
220/132 kV SS Kakinada in East Godavari Dist of Existing 3x100 MVA was commissioned on 26.11.2017 by APTRANSCO with augmented capacity of 1x60+2x100 MVA.
LILO of 220 kV Regumangadda- Gudipalligattu I to 220/11 kV SS Yelluru Water Grid Substation in Mehaboobnagar district of 7 Ckm was commissioned on 03.11.2017 by TSTRANSCO.
PTRs-2 220/11 kV SS Yelluru Water Grid Substation in Mehaboobnagar district of capacity 50 MVA was commissioned on 03.11.2017 by TSTRANSCO.
400/220 kV Maheshwaram in Existing 500 MVA was commissioned on 13.11.2017 by TSTRANSCO with augmented capacity of 500 MVA.
400/220 kV Narsapur in Existing 630 MVA was commissioned on 24.11.2017 by TSTRANSCO with augmented capacity of 315 MVA
9. Instances of SPS Operation
Based on the information furnished by SRLDC, it is informed that the following SPS operations took place in SR during the period 23.11.2017 – 17.12.2017:
Sl. No.
Date Time (hrs)
Reason Load relief obtained (MW)
AP KA KL TN TS Total
1 09-Dec-17 06:19
KKNPP Unit-1 tripped due to GT side problem. SPS operated leading to 590 MW load relief. Antecedent generation:1000 MW
100 215 171 104 0 590
Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 5
10. Status of Implementation of Protection Audit Recommendations (Phase-I & Phase-II)
With reference to the petitions filed by KSEB (88/MP/2016) and KPTCL (135/MP/2016) for seeking further time-extension for completing their respective Protection Audit Recommendations (PAR), the final Order of Hon’ble CERC disposing of petitions was issued on 15.12.2016. In this Order, the Commission, apart from granting last-chance time-extensions to various SR-Constituents, had also directed SRPC to monitor the status of completion of PAR regularly in PCSC meetings and submit bi-monthly report to the Commission confirming the completion of Phase-I and Phase-II of PAR of the Constituents of Southern Region.
In this regard, based on the information furnished by various Constituents, a summary table showing
the compliance status of various SR-Constituents as on 13.12.2017 is given below:
Sl.
No.
Constituent
PAR (Phase-I) Activities
PAR (Phase-II) Activities
PAR (Ph-I & Ph-II)
Compliance (%)
Remarks
Stipulated Completion Date
Stipulated Completion Date
1 APGENCO (Hydel)
31.12.2017 31.12.2017 53 ---
2 APGENCO (Thermal)
30.07.2017 --- 83.33 Based on the status furnished, timeline for complying with the remaining pending recommendations (2 in no.) is 30.06.2018. APGENCO (Thermal) has been asked to approach Hon’ble CERC to get required time-extension.
3 APTRANSCO 31.03.2017 --- 98.57 Based on the status furnished, the lone pending recommendation is expected to be completed by February, 2018.
4 TSGENCO (Hydel)
31.03.2017 31.03.2017 91.18 Based on the status furnished, timeline for complying with the remaining pending recommendations (3 in no.) is March, 2018.
5 TSGENCO (Thermal)
31.03.2017 31.03.2017 93.33 Based on the status furnished, the lone pending recommendation is expected to be completed by December, 2017.
6 TSTRANSCO 31.03.2017 31.03.2017 86.36 Based on the status furnished, timeline for complying with the remaining pending recommendations (12 in no.) is December, 2017.
Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 6
7 KPTCL 31.05.2017 31.05.2017 54.93 Based on the status furnished, timeline for complying with the remaining pending recommendations (32 in no.) is January, 2018.
8 TANGEDCO 31.12.2017 31.12.2017 75 Based on the status furnished, timeline for complying with the remaining pending recommendations (9 in no.) is June, 2018. TANGEDCO has been asked to approach Hon’ble CERC to get required time-extension.
9 TANTRANSCO 31.12.2017 31.12.2017 51.51 Based on the status furnished, timeline for complying with the remaining pending recommendations (64 in no.) is December, 2018. TANTRANSCO has been asked to approach Hon’ble CERC to get required time-extension.
10 KSEB 30.11.2016 31.12.2017 94.81 ---
11 NPCIL (MAPS) 31.01.2017 --- 88.89 Based on the status furnished, timeline for complying with the lone pending recommendation is March, 2018.
All above SR-Constituents were requested to complete their respective pending PAR. The IPP’s for whom there are pending PAR [viz., Spectrum PGL, Konaseema GPL, APGPCL Vijjeswaram (Stage-I & Stage-II), & LANCO-Kondapalli PL] were also requested to complete them at the earliest.
11. Nomenclature for naming various files uploaded in web-based Tripping Monitoring
System of SRLDC Portal
The nomenclature to be followed by the Constituents in naming various files (FIR, DR, EL, TR) corresponding to a tripping incident was brought out in the SRPC letter No. SRPC/ SE-III/ PCSC-45/ 4609 – 649 dated 26.06.2015 and in the minutes of PCSC-45 issued vide SRPC letter No. SRPC/SE-III/ PCSC-45/ 2015/ 5422-455 dated 21.07.2015. As illustrated therein, the format to be followed for the user entered part-name is given below:
Transmission Element File Name to be given by the user
Transmission Line SSN_DSN_line#_FT
Inter-connecting Transformer SSN_ICT#_FT
Generating Transformer SSN_GT#_FT
Generating Unit SSN_Unit#_FT
Minutes of the 70th
Meeting of PCSC held on 18th
December, 2017 Page 7
Where, SSN = Source Station Name/ From end Station Name/ Sending end Station Name DSN = Destination Station Name/ To end Station Name/ Receiving end Station Name FT = File Type (FIR/ DR/ EL/ TR)
All SR-Constituents are requested to kindly intimate the above file naming nomenclature to all the concerned and ensure that it is strictly followed at all the stations in their respective control areas so that tripping analysis can be done systematically.
12. Date & Venue of the next PCSC Meeting
It is informed that the 71st meeting of PCSC will be held on 31st January, 2018 (Wednesday) from 10:30 hrs onwards in the Conference Hall of SRPC Secretariat, Bengaluru.
*****
Annexure-I
Annexure-I
Annexure-I
Annexure-I
Annexure-I
Annexure-I
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 1/23
Analysis of Grid Occurrences - 70
I. Details of Grid Disturbances:
Sl. No.
Details of Event Date &Time Reason Remarks Category
1 Multiple trippings at 230 kV Madurai Substation
24-11-2017 at 12:11 hrs
All elements connected to 230 kV Main Bus-B got tripped due to spurious initiation of LBB
GD-1
SLD:
The single line diagram of 230 kV Madurai SS as furnished by TANTRANSCO is attached at the end. Bus-Configuration:
It was noted that all elements were connected to 230 kV Bus-B (Single-bus operation) at the time of tripping
Antecedent conditions:
230 kV Madurai – Amuthapuram S/C line was under L/C. Tripping of ICT-1 (PGCIL-SR2):
As per FIR/TR, ICT-1 tripped at 12:11:06 hrs on LV side due to BBP operation. It was stated in FIR that unwarranted LBB initiation of 230 kV Bus-B had caused BBP operation.
As per DR/EL, ICT-1 tripped at 12:11:06.038 hrs on LV side. (The type of protection operated was not recorded).
Tripping of ICT-2 (PGCIL-SR2):
As per FIR/TR, ICT-2 tripped at 12:11:06 hrs on LV side due to operation of BBP. It was stated in FIR that unwarranted LBB initiation of 230 kV Bus-B had caused BBP operation.
As per DR/EL, ICT-1 tripped at 12:11:06.040 hrs on LV side. (The type of protection operated was not recorded).
Tripping of 230 kV Bus-B of Madurai SS:
As per FIR/TR, 230 kV Bus-B tripped at 12:12 hrs due to LBB operation. It was stated that due to spurious LBB OPTO High Status in respect of ICT I & II in SEL 487B Bus Bar Relay, all the lines (except 230 kV Amuthapuram line) & ICTs – 1 & 2 connected to 230 kV Main-B Bus got tripped.
As per DR, LBB protection for 230 kV Main Bus-B operated at 11:03:03.307 hrs.
Time sync of BBP relay with GPS needed to be ensured at 230 kV Madurai SS.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 2/23
As per TANTRANSCO report dated 13.12.2017:
TANTRANSCO informed that the above works were completed on 14.12.2017.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 3/23
II. Details of Grid Incidents:
Sl. No. Details of Event Date &Time Reason Category
1 Tripping of 400/ 220 kV ICT-1 at Guttur Substation
07-11-2017 at 08:42 hrs
ICT-1 got tripped due to low SF6 gas pressure.
GI-2
Guttur (KPTCL) end:
As per FIR, ICT-1 tripped (only on 400 kV side) at 08:42 hrs due to low SF6gas pressure in R-phase CB. It was stated that leakage was observed in R-phase, and the same had been informed to ALSTOM service engineer & they were in the process of fixing the leakage issue.
As per DR, ICT-1 tripped at 07:41:15.734 hrs due to low SF6 gas pressure in R-phase CB.
Nothing could be deciphered from the furnished EL. (no relevant events were captured in it)
Time-sync issues at Guttur need to be addressed. KPTCL:
The old BHEL make 400 kV side CB of ICT-1 was replaced by a new CB of ALSTOM make on 03.07.2017. On the day of tripping, SF6 gas leakage problem was observed. As the pressure became less, the breaker got tripped.
Remedial action: The leakage issue with the CB was attended by ALSTOM Engineers on 09.11.2017.
Deliberations:
W.r.t. above, it was noted that the CB got tripped before going into lock-out; and the settings employed for the same are as follows: Low-Pressure Alarm: 6.2 bar; Low-Pressure Trip: 6.0 bar; Breaker Lockout: 5.0 bar
In this regard, the pros and cons of CB getting tripped on low-pressure before getting locked-out were discussed, when the prevalence of both the practices (a) “low-pressure trip preceding lockout”, and (b) “lockout preceding low-pressure trip” depending on the type of breakers being used was noticed. W.r.t. (a), the specific advantage of undertaking maintenance & overhauling of the concerned
CB without taking bus-shutdown was noted. W.r.t. (b), the specific advantage of maintaining same system conditions/ line flows due to
availability of the line even in locked out condition of the CB was noted.
It was also noted though practice (b) is majorly used, practice (a) is also in vogue esp. in some makes of CB’s in KPTCL/ KPCL stations.
After deliberations, it was agreed that while practice (a) seems to a good alternative to practice (b), in cases of critically loaded corridors and double/ multi circuit lines, practice (b) fares better than practice (a) due to better probability of ensuring status-quo w.r.t. prevailing grid conditions. Accordingly, Constituents were requested to exercise their wisdom in choosing the practice that is more pertinent to them.
2 Tripping of 400kV Kurnool-Srisailam line
07-11-2017 at 23:02 hrs
Line tripped on operation of Over-Voltage protection at Srisailam and Direct Trip was received at Kurnool. Considerable voltage difference was observed between R, Y & B phases.
GI-2 09-11-2017 at 21:57 hrs
12-11-2017 at 20:54 hrs
17-11-2017 at 21:19 hrs
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 4/23
FNN not followed by APTRANSCO and TSGENCO. OVR-400 gradings at 400 kV Srisailam LB PH:
Tripping on 07-11-2017:
Srisailam(TSGENCO) end:
As per FIR/DR/TR, line tripped at 23:02:24.137 hrs due to OVR-I operation.
EL not furnished. (In its place, Narnoor end EL furnished). Hence OVR-I’s time-grading could not be verified.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Narnoor (APTRANSCO) end:
As per FIR/DR/EL, line tripped at 23:02:24.165 hrs due to receipt of DT from the remote end. Tripping on 09-11-2017:
Srisailam (TSGENCO) end:
As per FIR/DR/EL/TR, line tripped at 21:57:51.807 hrs due to OVR-I (10 sec) operation.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Narnoor (APTRANSCO) end:
As per FIR/DR/EL, line tripped at 21:57:51.840 hrs due to receipt of DT from the remote end. Tripping on 12-11-2017:
Srisailam(TSGENCO) end:
No Tripping Files (FIR/DR/EL/TR) furnished.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Narnoor (APTRANSCO) end:
As per FIR/DR/EL, line tripped at 20:54:20.469 hrs due to DT receipt from the remote end. Tripping on 17-11-2017:
Srisailam(TSGENCO) end:
As per FIR/DR/EL/TR, line tripped at 21:59:37.810 hrs due to OVR-I (10 sec) operation.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Narnoor (APTRANSCO) end:
As per FIR/DR/EL, line tripped at 21:59:37.841 hrs on receipt of DT.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 5/23
Deliberations:
It was noted that no TSGENCO representative had come to the meeting to explain their perspective.
It was also noted that trippings at Srisailam end on OVR-I operation were not in accordance with the stipulated OVR gradings.
Further, considerable voltage difference was observed between R, Y & B phases at both ends. Also whether this phenomenon is prevalent only during over voltage conditions or also during normal voltage conditions needed to be ascertained. Accordingly, appropriate remedial measures like conduction of ratio test for the pertinent CVT’s, and their replacement may be decided upon.
Recommendations:
TSGENCO to adopt stipulated OVR, Stage-I gradings for the 400 kV lines emanating from their 400 kV Srisailam LB RH, and furnish an action taken report w.r.t. mitigating observed voltage difference among R & Y & B phases.
3 Tripping of 400 kV Satenapalli-Srisailam line-1
11-11-2017 at 22:02 hrs
Line tripped on operation of over-voltage protection at Srisailam and Direct Trip was received at Sattenapalli. Considerable voltage difference was observed between R, Y & B phases at Srisailam end.
GI-2 12-11-2017 at 23:09 hrs
24-11-2017 at 18:46 hrs
FNN not followed by APTRANSCO and TSGENCO. OVR-400 gradings at 400 kV Srisailam LB PH:
Tripping on 11.11.2017:
Srisailam (TSGENCO) end:
As per FIR/DR/EL/TR, line tripped at 22:02:53.300 hrs due to OVR-I (8 sec) operation.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Satenapalli (APTRANSCO) end:
As per FIR/DR/EL/TR, line tripped at 22:02:53.341 hrs on receipt of DT from the remote end. Tripping on 12.11.2017:
Srisailam (TSGENCO) end:
As per FIR/DR/EL/TR, line tripped at 23:09:27.898 hrs due to OVR-I (8sec) operation.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Satenapalli (APTRANSCO) end:
As per FIR/DR/EL/TR, line tripped at 23:09:27.940 hrs on receipt of DT from the remote end.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 6/23
Tripping on 24.11.2017:
Srisailam (TSGENCO) end:
As per FIR/DR/EL/TR, line tripped at 18:46:31.371 hrs due to OVR-I (8 sec) operation.
Tripping was not in order as per stipulated OVR gradings (the other lines should trip first). Satenapalli (APTRANSCO) end:
As per FIR/DR/EL/TR, line tripped at 18:46:31.412 hrs on receipt of DT from the remote end. Deliberations:
It was noted that no TSGENCO representative had come to the meeting to explain their perspective.
It was also noted that trippings at Srisailam end on OVR-I operation were not in accordance with the stipulated OVR gradings.
Further, considerable voltage difference was observed between R, Y & B phases at Srisailam. Also whether this phenomenon is prevalent only during over voltage conditions or also during normal voltage conditions needed to be ascertained. Accordingly, appropriate remedial measures like conduction of ratio test for the pertinent CVT’s, and their replacement may be decided upon.
Recommendations:
TSGENCO to adopt stipulated OVR, Stage-I gradings for the 400 kV lines emanating from their 400 kV Srisailam LB RH, and furnish an action taken report w.r.t. mitigating observed voltage difference among R & Y & B phases.
4 Tripping of 400/ 220 kV ICT-2 at Dindi SS
11-11-2017 at 19:35 hrs ICT-2 got tripped due to mal-operation of
Buchholtz relay
GI-2
26-11-2017 at 18:33 hrs
Tripping on 11-11-2017:
As per FIR/DR/EL, ICT-2 tripped at 19:04:56.535 hrs on operation of Buchholz relay.
It was stated in FIR that monkeys had climbed on to the transformer and operated the Buchholtz relay.
Tripping on 26-11-2017:
As per FIR/DR/EL, ICT-2 tripped at 18:33:20.149 hrs on operation of Buchholz relay.
It was stated in FIR that monkeys had climbed on to the transformer and operated the Buchholtz relay.
TSTRANSCO:
The line tripped on Buchholz relay indications. Tripped due to mal-operation as monkeys climbed on to the transformer tank and operated the Buchholz relay.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 7/23
5 Multiple trippings at 220 kV Talaguppa SS
13-11-2017 at 12:09 hrs
All elements connected to 220 kV bus got tripped due to operation of LBB protection in 220 kV Talguppa-Sharavathy line-2 at Talaguppa end.
GI-1
SLD:
The single line diagram of 220 kV Talaguppa SS as furnished by KPTCL is attached at the end.
Antecedent conditions:
220 kV Talaguppa - Sharavathy line-2 was under LC from 17.55Hrs on 12.11.2017 for attending line fault.
63 MVAR Bus Reactor was under OPEN condition from 9:20 hrs on 13.11.2017.
Remaining 220kV lines, viz., Sharavathy lines – 1 & 3, Sharavathy TR line and ICT-1, 2 & 3 connected to 220 kV Bus-I were in service.
Bus-Configuration:
It was noted that all in-service 220 kV elements were connected to 220 kV Bus-1 (Single-bus operation)
Tripping of ICT-1, ICT-2 and ICT-3:
As per FIR, ICT’s – 1, 2 & 3 tripped at 12:10 hrs due to LBB protection operation in 220 kV Talguppa - Sharavathy line-2 at Talaguppa end.
DR’s & EL’s not furnished. Tripping of Talaguppa – Sharavathy line-2: Talaguppa (KPTCL) end:
As per FIR/DR/EL/TR, Talaguppa end relay on 220 kV Talaguppa – Sharavathy line-2 had tripped in 3-ph at 12:09:29.251 hrs due to SOTF & DPR, Z1 (4.8 km) operation [Ir 160 A; Iy 141 A; Ib 161 A]
It was stated in FIR that due to induction for very short duration the above fault had initiated operation of LBB protection, and resulted in tripping of all 220 kV lines causing total bus shutdown.
In DR, analog waveforms and digital signals were without any names. Further no events related to LBB operation were captured in it.
In EL, no events relating to DPR operation or SOTF/ TOR operation or LBB operation were recorded.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 8/23
KPTCL:
At Talguppa, all the elements connected to 220 kV Bus-I got tripped due to due to LBB operation in ST-2 line bay.
On detailed verification of the ST-2 line DR, current of around 200 A (induction due to parallel line which is in charged condition - ???) was observed. During this, SOTF operated from M-II distance relay (Micom P442 commissioned recently) in ST-2 line and issued 3-ph trip resulting in operation of 86B trip relay. Due to continued current and 86B operation in ST-2, LBB operated after 200 msec and caused tripping of all the elements connected to 220 kV Bus-I. It was noted that since the 220 kV CTs are located on the line side after the line isolator, and since the earth isolator was closed at the point of line isolator for issue of LC, a path for the induced currents in the line was provided, which was measured by the line CTs.
Remedial action: It was analyzed that SOTF operated during the instance. The issue was taken up with the OEM,
M/s GE T&D India Ltd., and as per their suggestion setting under SOTF function had been modified and the relay had been tested. The relay is not operating for above conditions and working normally regarding other features.
There were two settings for operation of SOTF, viz.,(i) I > setting of 1.5 PU & 500 msec that operates with Voltage input, and (ii) ∆I > setting of 0.2 A that operates without Voltage input. The instant tripping was due to the second setting. As advised by OEM , this was revised to 0.5 A
Deliberations:
It was noted that the instant tripping was basically due to presence of protection CT on the line side of the line isolator, due to which a closed path was available for unbalanced current to flow (through earth-switch at from-end CT under reference line earth-switch at to-end earth) even after the line isolator was kept opened.
The cause of the tripping was due to sudden appearance of unbalanced current probably due to fault in immediately adjacent system, high enough to activate SOTF protection. It was noted that even though necessary remedial action had alreddy been taken by KPTCL to secure unwarranted operation of SOTF under referred conditions, the issue to be resolved is a more involved one. Because in the event of availability of voltage input, occurrence of a fault on the line could lead to flow of unbalanced current resulting first in operation of distance relay, and then ultimately in LBB relay.
It was noted that above type of mal-operations can occur in all those configurations (Double Main Bus/ Double Main Bus and Transfer Bus/ Single Main Bus & Transfer Bus) providing no line isolator after line protection CT. Hence, the proper remedy lies in effecting structural changes like providing another line-side isolator after line protection CT. This would also make possible maintenance of CT’s a hassle-free affair. It was noted that majority of the Utilities have taken care of this.
Other remedies suggested in this regard are given below: Shorting CT switching relay secondary using Isolator aux. contacts when the latter is in OPEN
condition. Making unavailable the DC Trip Voltage supply to Protection relay using Earth-Switch aux.
contacts when the latter is in CLOSED condition.
It was also noted that even though the first remedy (provision of line-side Isolator after protection CT) is ideal, wherever such provision cannot be provided for due to space constraints, the second remedy involving wiring-reconfigurations can be resorted to.
In this regard, KPTCL is requested to act according as what is best suited/ feasible to their system.
All Constituents were also requested to ensure either of the provisions are provided for line protection CT’s.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 9/23
6 Tripping of 400 kV Nellore-PG - NPS line-2
24.11.2017 at 13:06 hrs
Line tripped due to mal-operation of differential relay at NPS end and was in service from Nellore.
GI-2
24.11.2017 at 14:26 hrs
Tripping at 13:06 hrs: Nellore-PG (PGCIL-SR1) end:
As per FIR, line was kept holding from Nellore-PG end. Nellore-PS (PGCIL-SR1) end:
As per FIR/TR, line tripped at 13:05 hrs due to LDP operation. It was stated in FIR that LDP relay was commissioned in place of Main-1 Distance relay on 23.11.2017 at both ends.
As per EL, line tripped at 13:05:25.920 hrs due to 86B trip relay operation. (The type of protection operated was not recorded; also the line was being shown as Nellore-765 kV line)
As per DR, line tripped at 13:51:29.785 hrs due to 86A trip relay operation. (The type of protection operated was not recorded)
Tripping at 14:26 hrs: Nellore-PG (PGCIL-SR1) end:
Tripping files not furnished. (FIR & DR furnished were related to the previous tripping at 13:05 hrs)
Nellore-PS (PGCIL-SR1) end:
As per FIR/TR, line tripped at 14:26 hrs due to LDP operation. It was stated in FIR that LDP relay was commissioned in place of Main-1 Distance relay on 23.11.2017 at both ends.
As per EL, line tripped at 14:26:56.973 hrs due to 86B trip relay operation. (The type of protection operated was not recorded; also the line was being shown as Nellore-765 kV line)
As per DR, line tripped at 13:52:33628 hrs due to 86A trip relay operation. (The type of protection operated was not recorded)
Remedial action: The mal-operated LDP relay was replaced with spare on the same day i.e., on 24.11.2017.
Recommendations:
For the subject line, PGCIL (SR-I) to configure DR’s & EL’s of Line Differential Relays for recording all requisite protection operations at their Nellore PS.
7 Tripping of 400/ 220 kV ICT-1 at Talaguppa
25-11-2017 at 16:29 hrs
ICT-1 got tripped due to mal-operation of high set of Backup Over current relay
GI-2
30-11-2017 at 18:09 hrs
Tripping on 25-11-2017:
As per FIR/TR, ICT-1 tripped at 16:29 hrs due to mal-operation of R-ph high set of OCR relay (ABB make; RXPDK type), and inter-tripped 400 kV side.
DR & EL not furnished. Tripping on 30-11-2017:
As per FIR/TR, ICT-1 tripped at 18:09 hrs due to mal-operation of high-set & low-set of OCR relay (ABB make; RXPDK type), and inter-tripped 400 kV side.
DR & EL not furnished.
Remedial action taken by KPTCL: 220kV side B/U OC & EF relay was replaced by good relay available in the Substation on
01.12.2017 after testing.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 10/23
8 Tripping of 400 kV/ 220 kV ICT-3 at Vijayawada
27-11-2017 at 00:52 hrs
ICT-3 got tripped on operation of LV side over-flux protection.
GI-2 29-11-2017 at 00:47 hrs
Tripping on 27-11-2017 (PGCIL-SR1):
As per FIR/DR/TR, ICT-3 tripped at 00:52:39.501 hrs due to operation of LV side over-flux protection.
As per EL, ICT-3 tripped at 00:51:52.968 hrs due to operation of primary side over-flux protection.
Time sync of EL with GPS needed to be ensured at Vijayawada. As per SRLDC Preliminary Report, the V/f calculated from PMU data plot was 1.10% (approx.), and is
given below:
Tripping on 29-11-2017 (PGCIL-SR1):
As per FIR/DR/EL/TR, ICT-3 tripped at 00:47:40.081 hrs due to operation of LV side over-flux protection.
As per SRLDC Preliminary Report, the V/f calculated from PMU data plot was 1.10% (approx.), and is given below:
PGCIL (SR-I):
ICT-3 tripped at 27-11-2017at 00:52 hrs & 29-11-2017 at 00:47 hrs due to LV side O/F protection operation. At the time of tripping, higher voltages above 249kV & Frequency 50.00Hz were observed on LV ssdie at Vijayawada SS.
Adopted Over Flux settings for ICT-3 are as follows: 1.08 % Alaram 1.10 % Trip1 (6000 sec) 1.18 % Trip2 (90 sec) 1.26 % Trip3 (49.5 sec) 1.42 % 4 sec
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 11/23
Since O/F conditions prevailed on LV side for the required time [V/f value is 1.13 %], ICT-3 tripped on LV side.
However, it was noted that OFR operation at 220 kV level had not taken place for the Transformers owned by APTRANSCO and the other Transformers owned by PGCIL (SR-I).
Accordingly, PGCIL (SR-I) and APTRANSCO were requested to check the healthiness of OFR protection provided at 220 kV level to their respective Transformers at 400/ 220 kV Vijayawada (Nunna) SS.
9 Multiple trippings at 220 kV Guttur SS
30-11-2017 at 09:03 hrs
All elements connected to 220 kV Bus at 400/220 kV Guttur substation tripped. There was jumper cut due to which bus bar protection operated.
GI-1
SLD:
The single line diagram of 400/ 220 kV Guttur SS as furnished by KPTCL is attached at the end.
400 kV Bus 1
JSW
220kV Bus 2
Beeranahally
315MVA ICT-1
180MW
Munirabad
117
Narendra
2X30MW
Kaiga 2 X 2X84MW
400kV Bus-2
2
1
2
220kV Bus 1
2 X 214MW
Jogihally
Chitradurga
Neelagunda
a
Ranebennur
Haveri 1 &2
Davanagere
2 &3
315MVA ICT-2
46MW
Y phase jump (connected between Bus-I and Bus isolator)
got opened in Jogihally line bay resulting in bus fault.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 12/23
Bus-Configuration at the time of fault: 400 kV Side:
400KV Bus-I connected feeders: Kaiga-1, JSWEL and Beeranahally-2
400kV Bus- II connected feeders: Narendra 1 &2 , Beeranahally-1, Kaiga-2, Munirabad and 315 MVA ICT-1 &2
220 kV Side:
Due to problem with 220 kV side CB of ICT-1, it was taken on Bus-2 through Bus Coupler CB.
220kV Davanagere line-1 was under LC.
Remaining lines and ICT-2 were on Bus-1 Tripping of 400/ 220 kV ICT-1 (Guttur):
As per FIR/DR/EL/TR, ICT-1 tripped at 09:03:02.755 hrs due to BBP operation.
KPTCL informed that Jogihally bay Y-phase conductor from Bus-1 to Bus isolator got opened and created a bus-fault resulting in BBP operation of 220 kV.
10 Multiple trippings at 220 kV Hyderabad (Ghanapur) Substation
30-11-2017 at 12:02 hrs
All elements connected to 220 kV Bus-2 got tripped due to operation of Bus-bar protection during fault in 220 kV Ghanapur-Hayathnagar line-2
GI-1
SLD:
The single line diagram of 220 kV Hyderabad (Ghanapur) SS as furnished by TSTRANSCO is attached at the end.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 13/23
Bus-Configuration:
Tripping of 400/ 220 kV ICT-2 (PGCIL-SR1):
As per FIR/DR/TR, ICT-2 tripped at 12:02:03.199 hrs on LV side due to 220 kV BBP operation in TSTRANSCO’s 220 kV Hyderabad SS.
It was noted from DR that BBP operated after 200 msec of occurrence of fault. Tripping of 400/ 220 kV ICT-4 (PGCIL-SR1):
As per FIR/DR/TR, ICT-4 tripped at 12:02:16.451 hrs on LV side due to 220 kV BBP operation in TSTRANSCO’s 220 kV Hyderabad SS.
It was noted from DR that BBP operated after 200 msec of occurrence of fault. Tripping of 220 kV Ghanapur – Hayathnagar line-2:
As informed by TSTRANSCO, the line tripped on R-E fault with the following indications.
DR & EL not furnished. BBP operation at 220 kV Ghanapur SS:
FIR & DR & TR were furnished on 15.12.2017 (unacceptable delay)
As per FIR, BBP acted for 220 kV Bus-2 at 12:05 hrs for a through fault in 220kV Ghanapur-Hayathnagar-2 feeder.
As per DR, BBP operated on 220 kV Bus-2 at 11:53:10.275 hrs. As per TSTRANSCO’s Tripping Report dated 15.12.2017:
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 14/23
Remedial action proposed: The erratic fault currents in the secondary circuit of CTs may be due to improper discharge of
currents through earth. The earthing system of the 220 kV SS Ghanapur would be improved by measuring all the earth pit resistances and earth flats connectivity in the ground.
The ICT-1 and ICT-4 bus-bar CT secondary core star point would be earthed on par with other PUs, i.e., in the control room of 220 kV SS Ghanapur.
Recommendations:
TSTRANSCO to change star-point earthing of busbar core CT secondary of ICTs – 1 & 4 from the switchyard to the Control Room Panel, and then take appropriate measures to ensure earth-mat integrity at their 220 kV Ghanapur SS.
III. Details of Trippings due to Failure or Non-operation of Auto-Reclose:
Sl. No. Element Date & Time Reason
Category
1 Tripping of 220 kV Kadakola-Kaniyampeta line
01-11-2017 at 19:32 hrs
B-phase to earth fault had occurred in line. Breakers got tripped at Kadakola
GI-1
Kadakola (KPTCL) end:
As per FIR, line tripped in 3-ph at 19:32 hrs on B-E fault due to DPR, Z1 operation.
As per DR, line tripped in 3-ph at 18:32:22.627 hrs on B-E fault due to DPR, Z1 operation.
EL not furnished.
Time sync of Protection Relays with GPS needed to be issued. Kaniampeta (KSEB) end:
As per FIR, line tripped in B-ph at 19:32 hrs on B-E fault due to DPR, Z1 (A/R) operation and successfully Auto-reclosed.
From the DR furnished, loss of supply within 100 msec. of the occurrence of the fault was observed. (This was due to radial operation of the line from Kaniampeta end).
Remedial action taken by KPTCL: Additional logic is provided to block auto-reclosure during fault current more than 70 % of the
bus fault level. Non operation of AR from Kadakola end during the incident was verified during LC availed on
09.11.2017 and attended the problem with current limit setting for the above logic.
2 Tripping of 400 kV N’Sagar - Cudappah line
06-11-2017 at 3:27 hrs
B-phase to earth fault had occurred in line due to insulator de-capping. Voltage was persistent in R and Y phase at Cudapah end after A/R attempt.
GI-2
Nagarjuna Sagar (PGCIL-SR1) end:
As per FIR/DR/EL/TR, line tripped in B-ph at 03:27:03.147 hrs on B-E fault due to DPR, Z1 (A/R) operation, and auto-reclosed successfully after about 1.1 sec. However after about 0.4 sec to into the reclaim time, loss of SF6/N2/MCB & DPR, Z1 (Main-II) had operated to open the line in 3-ph. It was also observed that OVR-I protection had operated after about 2 sec into reclaim-time. It was further observed that Vr and Vy voltages were persisting till this point of time (2 sec), after which they slowly became zero].
Cudappah (PGCIL-SR1) end:
As per FIR/DR/EL/TR, line tripped in B-ph at 03:27:03.180 hrs on B-E fault due to DPR, Z1 (A/R) operation, and successful auto-reclosed after about 1.1 sec; however after about 0.4 sec to into the
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 15/23
reclaim time, DPR (Main-II) had operated to open the line in 3-ph.
DR time scale was found to be not sufficient to observe three phase trip.
From EL, it was observed that when the second fault occurred during Reclaim time, only Main-CB (352) got tripped in 3-ph. Whereas, Tie-CB (252) got tripped in B-ph only, due to which its other two phase poles got opened on PDR operation after about 1.2 sec (at 03:27:05.845 hrs).
Due to above, Voltages in R-ph and Y-ph persisted till PDR operation.
Remedial action: It was informed that the tripping was due to insulator decapping, and the concerned
replacement works were under progress.
3 Tripping of 400 kV NCTPS - Manali line
11-11-2017 at 7:18 hrs
Line tripped on R-phase to earth fault. At Manali end Auto reclose was Successful and at NCTPS end A/R is not in service.
GI-2
NCTPS (TANTRANSCO) end:
As per FIR/DR /TR, line tripped in 3-ph at 07:18:13.908 hrs on R-E fault due to DPR, Z1 (A/R; 1.063 km) operation.
Manali (TANTRANSCO) end:
As per FIR/DR/EL/TR, line tripped (in R-ph) at 07:18:13.911 hrs on R-E fault due to DPR, Z2 (A/R; CAT; 72.8 km) operation, and successfully auto-reclosed after about 1 sec.
TANTRANSCO:
NCTPS-II end Breaker was serviced on 14.10.2017 and charged. To watch its performance, AR was kept in OFF condition at NCTPS-II end.
A/R was put into service on 11.11.2017 during normalization of the feeder after the instant tripping.
4 Tripping of 400 kV Ramagundam-Chandrapur line-2
15-11-2017 at 13:17 hrs
R-phase to earth fault had occurred in line. line auto-reclosed at Ramagundam end
GI-2
Ramagundam (NTPC) end:
As per FIR/TR, line tripped in R-ph at 13:17 hrs on R-E fault due to DPR, Z1 (A/R; 51.89 km) operation, and successfully auto-reclosed after about 1 sec.
As per DR, line tripped in R-ph at 13:17:41.599 hrs on R-E fault due to DPR, Z1 (A/R) operation, and successfully auto-reclosed after about 1 sec.
As per EL, line tripped in R-ph at 13:17:30.448 hrs on R-E fault due to DPR, Z1 (A/R) operation, and successfully auto-reclosed after about 1 sec.
Chandrapur ( PGCIL –WR1):
No Tripping Files (FIR/DR/EL/TR) furnished.
As per SRLDC preliminary report, line got tripped at Chandrapur end.
It was noted that a decision to ensure that relevant tripping files are uploaded by PGCIL (WR-I)/ PGCIL (ER-I) in cases of concerned inter-regional trippings had been taken at SRPC board meetings. In this regard, User-Id and Password have also been provided to them to upload various tripping files in SRLDC’s TMS portal. However, whenever interregional trippings involving PGCIL lines take place, the tripping files from WR/ ER are either uploaded with unacceptable delay or not uploaded at all.
In this regard, MS, SRPC asked PGCIL (SR-I) to take up the issue with their WR counterparts, and ensure that they comply with IEGC Regulation 5.2 (r).
Recommendations:
PGCIL (SR-I) to furnish an action taken report on the reasons for A/R non-operation at Chandrapur end including remedial measures taken to PCSC forum.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 16/23
IV. Details of Trippings due to PLCC mal-operation:
Sl. No. Element Date & Time Reason
Category
1 Tripping of 400 kV Kaiga-Guttur line-2
01-11-2017 at 9:22 hr Line tripped on direct trip receive at both
Kaiga and Guttur
GI-2
02-11-2017 at 6:17 hrs
Tripping on 01-11-2017 Kaiga (NPCIL) end:
As per FIR/DR/TR, line tripped at 09:21:56.699 hrs on receipt of DT from the remote end.
As per EL line tripped at 09:23:02.875 hrs at due to receipt of DT from the remote end
Time sync of Protection Relays with GPS needed to be ensured at Kaiga GS. Guttur (KPTCL) end:
As per FIR/DR/EL/TR, line tripped at 09:18:52.818 hrs on receipt of DT from the remote end.
Time sync of Protection Relays with GPS needed to be ensured at Kaiga GS. Tripping on 02-11-2017 Kaiga (NPCIL) end:
As per FIR/DR/TR, line tripped at 06:16:39.880 hrs on receipt of DT from remote end.
As per EL, line tripped at 06:17:43.187 hrs on receipt of DT from remote end.
In DR, line currents were observed to have become zero even before DT Receipt. Guttur (KPTCL) end:
As per FIR, line tripped at 06:17 hrs on receipt of DT from remote end.
As per DR (Main-I), line tripped at 06:13:32.435 hrs on receipt of DT from remote end.
As per EL (Main-I), line tripped at 06:13:32.435 hrs. (The type of protection operated was not captured)
Remedial action taken by KPTCL: The Suspected non linear resistor in LA of LMU of 400kV Guttur-2 line at Kaiga end was replaced
on 02.11.2017. All signal levels were checked and found normal. No such tripping observed after attending the above problem.
NPCIL (Kaiga GS) was asked to examine the reasons for line currents becoming zero even before DT is received in the DR for the tripping event 02.11.2017, and rectify them appropriately at the earliest.
2
Tripping of 400kV Maheshwaram (TS)-Maheshwaram (PG) - 1 & 2 and 400 kV Maheshwaram (TS)-Shankarapalli – 1 & 2
02-11-2017 at 11:32 hrs
Lines got tripped due to suspected DC earth at Shankarapally. All these lines are connected to 400 kV Bus-1 at Maheshwaram TS
GI-2
SLD:
The single line diagram of 400/ 220 kV Maheswaram (TS) as furnished by TSTRAANSCO is attached at the end.
Bus Configuration:
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 17/23
400 kV Maheshwaram(TS) - Maheshwaram (PG) line-1: Maheshwaram-TS (TSTRANSCO) end:
As per FIR, line tripped at 11:32 hrs on receipt of DT due to DC earth leakage at Maheshwaram (TS).
DR & EL not furnished. Maheshwaram-PG (PGCIL-SR1) end:
As per FIR/DR/EL, line tripped at 11:32:11.926 hrs on receipt of DT from remote end. Maheshwaram(TS) - Maheshwaram (PG) line-2: Maheshwaram-TS (TSTRANSCO) end:
As per FIR, line tripped at 11:32 hrs on receipt of DT due to DC earth leakage at Maheshwaram (TS).
DR & EL not furnished. Maheshwaram-PG (PGCIL-SR1) end:
As per FIR/DR line tripped at 11:34:58.947 hrs on receipt of DT
As per EL line tripped at 11:34:56.104 hrs on receipt of DT 400 kV Maheshwaram(TS) – Shankarapalli lines – 1 & 2: Shankarapally (TSTRANSCO) end:
As per FIR, line was kept holding at Shankapally end. Maheshwaram-TS (TSTRANSCO) end:
As per FIR line tripped at 11:32hrs on receipt of DT due to DC earth leakage at Maheshwaram (TS).
DR & EL not furnished. As per Tripping Report furnished vide TSTRANSCO mail dated 15.12.2017:
During the tripping event, 500MVA ICT-2 construction works were in progress. By oversight, the AC supply was given in the Terminal Block of Cooler Control Cubicle(CCC) of ICT-2 in which the other end of Terminal Block DC supply was already extended. Due to which both AC and DC supply were mixed together and caused carrier tripping of the 400kV feeders by sending Direct Trip Signals. Also no DR & ELs were triggered at Maheshwaram SS.
Remedial action: Later the AC supply is removed and instructed the working staff to check thoroughly while
extending the AC or DC supply and to use separate DC source for construction, testing and pre-commissioning of new equipment.
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 18/23
3 Tripping of 400 kV Ramagundam - Gajwel line
21-11-2017 at 17:17 hrs
Line tripped on direct Trip receive indications at Gajwel end only and was in service from Ramagundam
GI-2
Ramagundam (NTPC) end:
As per FIR, line was kept holding from Ramagundam end. Gajwel (TSTRANSCO end:
As per FIR, line tripped at 17:17 hrs on receipt of DT.
DR & EL not furnished. TSTRANSCO:
Line tripped at Gajwel end only as Direct Trip was received from Ramagundam end. PLCC increment was observed at Gajwel end.
Recommendations:
For the line under consideration, the following shall be carried out by TSTRANSCO in coordination with NTPC-Ramagundam: (i) End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends. (ii) Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty components shall be repaired/ replaced.
*****
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 19/23
Single Line Diagram of 220 kV Talaguppa SS of KPTCL (Ref: II.5)
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 20/23
Single Line Diagram of 230 kV Madurai SS of TANTRANSCO (Ref: II.7)
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 21/23
Single Line Diagram of 400/ 220 kV Guttur SS of KPTCL (Ref: II.10)
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 22/23
Single Line Diagram of 220 kV Hyderabad (Ghanapur) SS of KPTCL (Ref: II.11)
Annexure-II
Grid Occurrences to be discussed in the 70th Meeting of PCSC scheduled to be held on 18thDecemeber,2017 23/23
Single Line Diagram of 400/ 220 kV Maheswaram (TS) SS of TSTRANSCO (Ref: IV.2)
Annexure-II
Meeting No /
Index
Details of Event Date & Time Reason PCSC Recommendations Utility responsible
for Implementation
Status of Recommendations
as on 05.01.2018
Remarks
KPTCL Mail dated 16.12.2017:
1. Shut downs have be planned.PGCIL coordination is required.
--- Pending
Pending Implementation of PCSC Recommendations (up to 70th Meeting)
KPTCL Mail dated 27-05-2015:
1. KPTCL has taken action to provide bus bar protection to 220kV buses. -
-- Pending
2. Over current relay Settings of ICTs to be reviewed by PGCIL.
--- Pending
3. --- Pending
KPTCL Mail dated 29-07-2015:
1. Initial Tendering stage. --- Pending
2. --- Pending
3. --- Pending
KPTCL Mail dated on 23-01-2016:
1. Detailed estimate prepared for taking up the work. CEE, Transmission
Zone, Gulbarga will take up necessary procurement and further
execution. --- Pending
2. --- Pending with PGCIL (SR-I).
3. --- Pending
PGCIL (SR-I) Mail dated 14.07.2016:
2. Relay settings of all the stations in SRTS-1 were derived as per
Ramakrishna Commettee recomendations and implemented" ---
Completed.
Multi-Utilities
KPTCL Mail dated 16.12.2017:
1) & 3). DPR is approved. Tender is to be called by CEE,TZ Kalaburgi ---
Pending
Review Meeting dated 19.12.2017:
1. KPTCL informed that Tenders for providing BBP would be called in Jan-
Feb, 2018; Supply of the same is targeted by September, 2018; Erection
& Commissioning is targeted by January, 2019 --- Pending
3. PGCIL (SR-I) informed that time-synchronization of 220 kV side is in
place. --- Completed.
16-07-2014
40/II/3 Tripping of 400
kV TALAGUPPA
– HASSAN line
On account of R-phase to earth fault, line tripped at
Hassan end due to operation of distance Zone-2 and
non-receipt of carrier. From D.R of Talaguppa end it
is observed that fault had occurred in Yphase.
1. PGCIL and KPTCL to ascertain the reason for the phase discrepancy in
the relay operation and take suitable remedial measures.
2. KPTCL to check the PLCC operation at Talaguppa end and submit the
report to the PCSC forum.
PGCIL (SR-II)/ KPTCL PendingMail recieved on 28-04-2015:
1. --- Pending
2. End to end testing of PLCC has been done and problem in the PLCC is
atttended. --- Completed
Mail received on 27-05-2015 (KPTCL) & 29-07-2015:
1. Phase discrepancy in the relay operation is to be checked jointly. ---
Pending
2. End to end testing of PLCC has been done and problem in the PLCC is
atttended. --- Completed
Mail recieved on 02-09-2015 from PGCIL (SR-II):
1. Problem is in identification of phases at Talguppa end. To be rectified
by M/s KPTCL. ----- Pending
Mail recieved on 28-06-2016 from KPTCL:
1. The matter is reffered to the concerned Operation and maintance
wing to set right the mismatch of phases in 400kV Talaguppa-
Nelamangala and Talaguppa-Shantigrma lines at Talaguppa in
cordination with PGCIL . --- Pending
01-01-2015
at 13:38 hrs
34/I/6 400/220 kV ICT-1 & 2 at Munirabad As reported directional over current relay of ICT’s
operated due to snapping of line jumper in 220kV
Lingapur line.
1. Bus bar protection shall be provided by asset owner ( i.e KPTCL).
2. Settings for main distance protection & Overcurrent protection shall
be examined and reviewed.
3. Time synchronization of the Substation shall be ensured.
KPTCL/
PGCIL (SR-I)
Pending
(with KPTCL)
Annexure-III
Page 1 of 37
Review Meeting dated 19.12.2017:
1. KPTCL informed that the required work in proposed to be carried out
on HV (400 kV) side. Tedners for the same would be called by February,
2018, and the work is targeted to be completed by August, 2018.
APGENCO letter dated 18.03.2016:
1.SOE and SLD are attached. The DR of 405 CB is not generated during
the incident. Now the problem is identified and rectified.
--------- Completed
2.All the 3 lines i.e CHTR-2, MNBL-I & II tripped in zone
protection. The fault was in Blind zone i.e P2 side of CT, where it was
covered under Bus fault by the time fault moved on to P1 side when the
fault comes under STUB/TEED zone after 330msec all the feeders expect
CHTR-1 tripped in Zone-II and total fault persisted for 500msec before
the 405 TIE CB opens and clear the fault. As a remedial the STUB
protection operation also checked and found OK.------- Completed
3.The Time Sync was missed on the day and found there was problem
with LAN Timer same was rectified. Now found OK.
-----------Completed
4.Now the DR Time scale changed to 1 sec for Pre fault and 3 sec for Post
fault and STATE of events are corrected wherever found wrong/or
misguiding during analysis.---------Completed.
5.
PGCIL-SR1 RVMD 27-04-2016:
Procurement of differential protection for 400kV NPS-NLR D/C and
400kV RCR-RTPS-D/C is under tendering.
PGCIL-SR1 RVMD 14-07-2016:
The proposal for procurement of Line differential Protections for 400kV
Raichur - RTPS-1 & 2 and 400kV Nellore - NPS - 1 & 2 lines has been
approved and tender is under technical evaluation
Pending
[with
PGCIL (SR-I)]
PGCIL (SR-I) Mail dated 15.12.2017:
PGCIL: On 23.11.2017 LDP relays commissioned in place of Main-1
distance relay in 400kV NPS-Nellore line-2 & In line-1 installation of LDP
relay is planned in Dec-2017/Jan-2018.
Review Meeting dated 19.12.2017:
5. PGCIL (SR-I) informed that LDP commissioning on both lines would be
completed by February, 2018. In this regard, PCSC made it clear that the
recommendation pertains to providing LDP as both Main-I & Main-II on
both the lines, and asked PGCIL (SR-I) to ensure & comply with the same.
APGENCO/
PGCIL (SR-I)
1. APGENCO to furnish to PCSC forum (i) A3-size Single Line Diagram of
SDSTPS, and (ii) the sequence of events with time stamp showing the
protection that opened Tie-CB (405) at SDSTPS.
2. APGENCO to review STUB/TEED protection in all dias at SDSTPS and
ensure that they are configured for instantaneous operation.
3. APGENCO to properly configure the STATE of the tripping events so
that they get recorded appropriately like TRIP/ OPERATED in their
corresponding Event Loggers.
4. APGENCO to ensure time sync of all DR’s and EL’s at SDSTPS.
5. PGCIL (SR-I) to provide line differential protection for 400 kV NPS
–Nellore-PG lines 1 & 2.
As per FIR submitted, CT damage observed in
Chitoor-Main bay (404). Main breakers connected to
bus-1 (401, 404, 407, 410) got tripped on operation
of bus bar protection. Unit-1 tripped on operation of
MFT. Unit-2 was not in service
Complete outage of Krishnapatnam TPS47/I/2 08-09-2015
at 18:20 hrs
Annexure-III
Page 2 of 37
Review Meeting dated 19.12.2017:
1. KPTCL informed that since the line is a double circuit, there may not
be need for implementing Weak Infeed logic with Echo feature at Karwar
end. However, the same would be looked into w.r.t. the newly
commissioned NR's at Karwar, and final action taken would be informed
by March, 2018.
220kV Kadra-Karwar lines-1&2 tripped
on earth fault in B-phase in zone-2.
Kaiga-Kadra line tripped at Kaiga end
only on operation of directional eath
fault protection.
Tripping of 220 kV Kadra-Karwar lines - 1&2
and 220kV Kaiga-Kadra line
47/II/7
50/I/2 Complete outage of TPCIL power station 1.PGCIL (SR-I) to furnish Action Taken Report on the findings of OEM on
relay mal-operation at NPS end on 400 kV NPS – NCC line to PCSC forum.
2. PGCIL (SR-I) to appropriately configure Station Event Logger at NPS to
record events at msec interval.
3. PGCIL (SR-I) to carry out PLCC end-to-end testing in coordination with
TPCIL for 400 kV NPS –TPCIL line.
4.PGCIL (SR-I), MEPL, SEL, TPCIL & NCC to take steps to provide line
differential protection at their respective ends on all 400 kV lines (except
Gooty line) emanating from Nellore Pooling Station, and furnish an
action plan to implement the same.
30-12-2015 at
06:02hrs
1. KPTCL/ KPCL to see the possibility of implementing Weak Infeed logic
with Echo feature enabled by Under
Voltage (27) element on Kadra-Karwar lines 1 &2, and implement the
same if feasible.
2. NPCIL to time-coordinate Kaiga’s DEFR settings with (i) Zone-2 settings
at Kaiga, and (ii) primary protections of the lines emanating from Kadra
and Kodasalli.
3. KPCL to ensure time-sync of EL’s, and healthiness of the Fault Locators
at Kadra.
PGCIL (SR-I) mail received on 27-04-2016:
1. The firmware of REL670 is being upgraded. ------- Completed.
2. The recording of events in msec interval is being taken up with OEM.
Henceforth, for analysis purpose, we will provide larm list which has
msec time stamp. -------- Completed.
3. End to end testing of PLCC code transmision and tuning of channels
carried out. ------- Completed.
4. Procurement of differential protection for 400kV NPS-NLR D/C and
400kV RCR-RTPS-D/C is under tendering. The legends modified in
Event/alarm list. Provision of diff. relay for all short lines emanating
from NPS is being taken up with our corporate.
----- Pending.
PGCIL(SR-I) RVMD 14-07-2016:
4. The proposal for procurement of Line differential Protections for
400kV Raichur - RTPS-1 & 2 and 400kV Nellore - NPS - 1 & 2 lines has
been approved and tender is under technical evaluation --- Pending
PGCIL (SR-I),
MEPL, SEL, TPCIL, NCC
Pending
KPTCL Mail recieved on 25-05-2016:
1. Availability of week end infeed with eco feature to be confirmed by
SEE,RTC,Hubli --- Pending.
NPCIL (KGA) Mail recieved on 03-12-2016:
2. The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga
Kodasally lines were disabled. IDMT DEFR is retained. The 200 ms
Definite time back up o/c element in both Kaiga Kadra and Kaiga
Kodasally lines were disabled. IDMT is retained. --- Completed.
Status received vide KPCL mail dated 14.06.2017 & 29.11.2017:
1. Since PT blasted (B phase) at Karwar end, resistive over reach
occurred. hence Backup protecion operated at Kadra end (zone-2 not
sensed) --- Pending.
2. ---- Completed
3.Newly commissioned micom P444 relay time synchronised with GPS
------ Completed.
KPTCL Mail dated 16.12.2017:
1. Week end infeed logic will be enabled in the new numerical relays
supplied to Karwar under R&U during retrofitting works.
--- Pending
Pending
[with KPTCL]
KPTCL/ KPCL/
NPCIL (KAPS)
31-07-2015 at
11:44 hrs
Running units at Thermal Powertech power Station
tripped due to tripping of 400kV Nellore pooling
station (NPS)-TPCIL line and 400kV Nellore pooling
station (NPS)-NCC line
Annexure-III
Page 3 of 37
1. PGCIL (SR-I), in co-ordination with APTRANSCO, to address the
problem with CB at the earliest opportune time.
2. APTRANSCO to take steps to replace the faulty Event Logger at
Vijayawada (Nunna) SS.
Line tripped due to operation of over voltage
protection at Vijayawada end and Direct Trip was
received at Sattenapalli end
25-12-2015 at
3:01 hrs
Tripping of 400kV Sattenapalli-Vijayawada
line
51/II/6
Line tripped at Mamidipally end only on Direct Trip
receipt from Ghanapur end
30-04-2016 at
16:40 hrs
54/IV/2
PGCIL (SR-I)/
APTRANSCO
PGCIL mail received on 27-04-2016:
Being pursued with APTRANSCO
APTRANSCO mail dated on 22-06-2016:
AS maintenance being carrired out by PGCIL(SR-1), the required relay
replacement (wiring/programming) may also be carried out by PGCIL(SR-
1).
PGCIL RVMD 14.07.2016:
1. The CB problem has been attended by POWERGRID by using OEM M/s
BHEL services & POWERGRID's O&M spares.
------ Completed.
2. Being pursued with APTRANSCO to replace the faulty Event Logger at
Vijayawada (Nunna) SS. ---- Pending
APTRANSCO mail dated on 31-08-2016 & 04.03.2017 & 24.05.2017:
As maintenance being carrired out by PGCIL(SR-1), the required relay
replacement (wiring/programming) may also be carried out by PGCIL(SR-
1).
APTRANSCO mail dated 20.10.2017:
May be coordinated with PGCIL
APTRANSCO mail dated 22.11.2017:
PGCIL may be requested to take necessary action
APTRANSCO mail dated 15.12.2017:
2. EL procured and drawn. Configuration to be done by Alstorm company
engineer. Will be configured in four weeks.
---Pending
For the line under consideration, the following shall be carried out by
TSTRANSCO and PGCL (SR-I) in co-ordination:
(i) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(ii) Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
PGCIL (SR-I) Mail dated 15.12.2017:
2. APTRANSCO is to replace the faulty/outdated relays & POWERGRID
has to maintain the relays after retrofitting.
Review Meeting dated 19.12.2017:
2. APTRANSCO informed that the recommended works would be
completed in one-month period.
PGCIL (SR-I)/
TSTRANSCO
PGCIL (SR-I) Mail dated 15.12.2017:
ABB make protection coupler is extending DT during DC leakages. TS
TRANSCO to takeup the issue with ABB for Ghanapur-Mamidipally line &
by APTRANSCO for Gazuwaka-Kalpaka lines.
Review Meeting dated 19.12.2017:
After considering issues narrated by PGCIL (SR-I) and TSTRANSCO, the
following were decided:
(i) PGCIL (SR-I) would look into DC leakage related issues at their 400 kV
Ghanapur SS, and rectify the same, if any, by second week of January,
2018.
(ii) TSTRANSCO would arrange for testing of PLCC equipment & panels by
their OEM (ABB) and get the issues sorted out in coordination with PGCIL
(SR-I) by 20.01.2018.
PGCIL (SR-I) Mail dated 15.12.2017:
4. LDP relays procurement is under process. Procurement will be
completed by Feb-2018. TPCIL has to give written confirmation for LDP
relay procurement. For want of written confirmation from TPCIL, PGCIL
approving authority has withheld the LDP proposal.
Review Meeting dated 19.12.2017:
4. PGCIL (SR-I) informed that they are waiting for written confirmation
from TPCIL to complete procurement of LDP relays. To this, PCSC forum
asked TPCIL to submit written confirmation to PGCIL (SR-I) by
29.12.2017. PGCIL (SR-I) assured that with receipt of above confirmation
from TPCIL by Dec, 2017, they would be able to complete the work by
FEbruary, 2018.
APTRANSCO informed that they would be able to implement LDP from
their & APGENCO side by April, 2018.
In this regard, PCSC forum made it clear that the recommendation is
about providing LDP as both Main-I & Main-II relays on all stated lines in
Nellore Complex, ans asked all stakeholders to ensure & comply with the
same.
Pending
Pending
[with APTRANSCO]
Tripping of 400kV Ghanapur-Mamidapalli
line
Annexure-III
Page 4 of 37
1.TSTRANSCO and SCCL to check drop-off to pick-up ratio of OV relay and
ensure that it is kept at 0.97 & above.
2.TSTRANSCO and SCCL to configure respective end ‘s DR & EL so that
they get triggered on OVR protection, and record relevant events.
3.SCCL to configure Jaipur end relay’s EL properly so that the time-stamp
resolution is extended downwards up to milli-second level.
Complete outage of 220kV Sedam
Substation of KPTCL.
Tripped on 3-phase Trip at Gajwel end
APTRANSCO/
PGCIL (SR-I)
220kV Sedam-Humnabad-2 tripped at Sedam on
Distance protection, Zone-2. Sedam-RTPS-1 &2 lines
tripped at RTPS end only. 220kV Tandoor inter-state
line was hand tripped due to incoming supply failure
Review Meeting dated 19.12.2017:
It was decided that since SCCL is an intra-state embedded generator of
Telangana, TSTRANSCO would henceforth monitor & ensure the
compliance of given recommendations by SCCL, and inform the status in
this regard to PCSC forum.
Tripping of 400 kV Gajwel-Singareni line-2 Pending
Pending
APTRANSCO maild ated 15.12.2017:
1. Cable healthiness checked and found ok. But it is proposed to replace
the cable with armored cable. --Completed
2. After replacing the cable contactors will be removed so as to avoid
unwarrented delays in transmitting trigging signal to the central unit . ---
Pending
Review Meeting dated 19.12.2017:
APTRANSCO informed that replacement of the existing cable with
armoured cable and subsequent removal of cable contactors would be
completed by 31.12.2017. In this regard, PGCIL (SR-I) also assured that
they would render all required help from their side to complete the
stated works in time.
24-06-2016 at
16:04 hrs
KPTCL and TSTRANSCO to take steps to provide A/R feature on 220 kV
Sedam – Tandur inter-state line at their respective ends at the earliest.
19-06-2016 at
15:27hrs
TSTRANSCO/
SCCL
KPTCL/
TSTRANSCO
(SR-I) by 20.01.2018.
Pending
[with KPTCL]
KPTCL Mail dated 16.12.2017:
Carrier protection is to be restored. B/U OC and EF relay is to be
replaced by M-II distance relay. Required materials like wave trap, M-II
distance relay are already supplied. The work will be taken up on top
priority through GE Ltd. --- Pending
Review Meeting dated 19.12.2017:
TSTRANSCO informed that they have kept A/R in service from Tandur
end. KPTCL informed that the works relating to put A/R in service are
going on at their Sedam SS, and assured that it would be put into service
by February, 2018.
56/II/16
56/I/2
APTRANSCO mail dated on 31-08-2016:
To avoid the unwanted malopeartions due to the external LBB trip
initiation from PGCIL, Vide letter Dt: 04-08-2016, APTRANSCO has
requsted the PGCIL to arrange the Master trip relay and breaker
contacts of ICT-1 &2 LV side to enable the internal LBB feature in the
Busbar protection scheme at 220kV Gooty Switching station. Waiting
for the PGCIL response.
APTRANSCO mail dated on 15-11-2016:
To avoid the unwanted maloperations due to the external LBB trip
initiation from PGCIL, vide letter Dt: 04-08-2016, ARTRANSCO has
requested the PGCIL to arrange the Master trip relay and breaker
contacts of ICT-1&2 LV side to enable the internal LBB feature in the
Busbar protection scheme at 220kV Gooty Switching station. Waiting for
the PGCIL response.
APTRANSCO mail dated on 20-12-2016:
Waiting for the PGCIL response.
APTRANSCO mail dated 04.03.2017 & 24.05.2017.
SRPC is requested to coordinate with PGCIL in takind necessary action.
APTRANSCO mail dated 20.09.2017 & 22.11.2017
PGCIL may be requested to take necessary action
30.06.2016
at 23:43 hrs
LBB protection got operated for 400/220kV ICT-2
breaker which had resulted in tripping of 220kV Bus-
2 at 220kV Gooty Substation
Tripping at 220 kV Gooty Substation of
APTRANSCO
56/II/13 1.APTRANSCO to check the healthiness of the connecting cable between
Gooty (PGCIL) and Gooty (APTRANSCO), and replace it, if required.
2.APTRANSCO to ensure that the distributed architecture employed in
implementing busbar protection at their Gooty 220 kV SS does not
introduce any unwarranted delays in transmitting the triggering signals
to the Central Unit.
Annexure-III
Page 5 of 37
10-07-2016 at
1:56 hrs
Triggering incident was failure of R phase PT in Bus-1
at 220kV Karwar substation. 220kV Kaiga-Kodasalli
tripped during the incident. Also bus shut down
occurred at Kadra and Kodasally stations.
Tripping of 220 kV Sedam-Tandur line
57/II/4
1.NPCIL (KAPS) to disable DefiniteTime O/C relay, and put in its place by
IDMT O/C relay for backup protection on both 220 kV Kaiga – Kadra line
and 220 kV Kaiga – Kodasalli line at Kaiga end.
2.KPTCL to put bus bar protection in service at their 220 kV Karwar SS at
the earliest.
3.KPCL/ KPTCL to implement Weak In-feed Logic with Echo feature
enabled by Under Voltage (27) element on Kadra – Karwar lines 1 & 2.
4.KPTCL to furnish equipment failure report of the current incident to
PSE&TD Division of CEA with a copy marked to SRPC.
Tripping of 400 kV Gajwel-Singareni line-2 Line tripped on operation of Over-Voltage
protection at Singareni and Direct Trip was received
at Gajwel. DR & EL of Singareni was not furnished
Triggering incident was snapping of Y phase
conductor in 400kV Nellore (PG) - NPS line-1.
Distance relay at Krishnapatnam end over-reached
in Zone-1, and resulted in tripping of 400kV
Krishnapatnam – Nellore (AP) lines - 1&2 from
Krishnapatnam end. Distance relay at MEPL over-
reached and resulted in tripping of MEPL-NPS line
from MEPL end.
PGCIL (SR-I), TPCIL, MEPL, SEL, SGPL, APTRANSCO, APGENCO and SDSTPS
to implement line differential protection on all 400 kV transmission lines
(of length less than 50 km) emanating from Nellore PS, Nellore (PG) SS,
and Nellore (AP) SS. [It may be noted here that the cut-off length of 50
km has been specified with a view to exclude only long transmission
lines].
APGENCO/
PGCIL(SR-I)/
TPCIL/MEPL/SEL/
SGPL/ APTRANSCO
Pending
[with KPCL & KPTCL]
Pending
PendingKPTCL/
TSTRANSCO
PendingReview Meeting dated 19.12.2017:
It was decided that since SCCL is an intra-state embedded generator of
Telangana, TSTRANSCO would henceforth monitor & ensure the
compliance of given recommendations by SCCL, and inform the status in
this regard to PCSC forum.
1.Singareni TPS to furnish single line diagram of their switchyard along
with the Over Voltage Relay settings adopted for various transmission
lines, and to ensure that they are in line with the SRPC provided
gradings.
2.Singareni TPS to upload various tripping files (FIR/DR/EL/TR) pertaining
to a tripping event involving their station in SRLDC web-portal within 24-
hrs of occurrence of that event in compliance of IEGC Regulation 5.2(r).
57/II/9
TSTRANSCO/ SCCL
57/I/1 Complete outage of 220 kV Karwar
Substation of KPTCL
Tripping of 400 kV Nellore (PG) - NPS line-
1, 400 kV Krishnapatnam-Nellore (AP) lines -
1&2 and 400kV NPS - MEPL line
18-07-2016
at 19:05 hrs
KPTCL/ KPCL/
NPCIL (KAPS)
NPCIL(KGS) mail dated on 03-12-2016 & 29.11.2017:
1.The 200 ms Definite time DEFR element in both Kaiga Kadra and Kaiga
Kodasally lines were disabled. IDMT DEFR is retained. --- Completed
2. --- Pending
3. --- Pending
4. --- Pending
KPTCL Mail dated 16.12.2017:
2) Bus-bar protection panel is supplied under R&U. Replacement work
will be taken up after priority Sub stations.
--- Pending
3] Weak end Infeed logic available in new relays supplied; Will be
enabled During R&U works. --- Pending
4] Equipement failure reports are being sent to CEA regularly.
--- Completed
Review Meeting dated 19.12.2017:
2. KPTCL informed that the works relating to providing BBP are targeted
to be completed by March, 2018.
3. KPTCL informed that since the line is a double circuit, there may not
be need for implementing Weak Infeed logic with Echo feature at Karwar
end. However, the same would be looked into w.r.t. the newly
commissioned NR's at Karwar, and final action taken would be informed
by March, 2018.
APTRANSCO mail dated on 20-12-2016:
Issue was addressed to the concerned for necessary action.
APTRANSCO mail dated on 24-05-2017:
Meeting was conducted and the relays procurement for all the loctions
is under progress.
APTRANSCO mail dated on 20-10-2017 & 22.11.2017:
Relays procurement for all the locations is under progress.
APTRANSCO Mail dated 15.12.2017:
Technical bids opened. PQ evaluation under progress . Price bids
expected to open in next week.
PGCIL (SR-I) Mail dated 15.12.2017:
LDP relays procurement is under process. Procurement will be
completed by Feb-2018. TPCIL has to give written confirmation for LDP
relay procurement. For want of written confirmation from TPCIL, PGCIL
approving authority has withheld the LDP proposal.
Review Meeting dated 19.12.2017:
PGCIL (SR-I) informed that they are waiting for written confirmation from
TPCIL to complete procurement of LDP relays. To this, PCSC forum asked
KPTCL and TSTRANSCO to fast-track providing A/R on 220 kV Sedam –
Tandur line, and furnish an action plan of providing the same by next
PCSC meeting (PCSC-57).
Line tripped on B-phase to earth fault. Auto-reclose
is not enabled for line.
KPTCL Mail dated 16.12.2017:
Carrier protection is to be restored. B/U OC and EF relay is to be
replaced by M-II distance relay. Required materials like wave trap, M-II
distance relay are already supplied. The work will be taken up on top
priority through GE Ltd.
Review Meeting dated 19.12.2017:
TSTRANSCO informed that they have kept A/R in service from Tandur
end. KPTCL informed that the works relating to put A/R in service are
gonig on at their Sedam SS, and assured that it would be put into service
by February, 2018.
56/III/4 03-06-2016
at 21:52 hrs
12-07-2017
at 11:36 hrs
Annexure-III
Page 6 of 37
63/III/4 Tripping of 400 kV Gajwel-Singareni line-2 07-03-2017 at
16:52 hrs
Line tripped on B-phase to earth fault. Line did not
auto-reclose.
1. SCCL to properly configure LBB logic for all line relays, where
A/R has been put into service, for 1-ph initiation based on phase
segregation (i.e., for the faulted phase) at their Singareni TPS.
TSTRANSCO/ SCCL Review Meeting dated 19.12.2017:
It was decided that since SCCL is an intra-state embedded generator of
Telangana, TSTRANSCO would henceforth monitor & ensure the
compliance of given recommendations by SCCL, and inform the status in
this regard to PCSC forum.
Pending
64/I/1 Complete outage of North Chennai TPS
STG-2
24-04-2017
at 21:02hrs
Tripping of evacuating lines due to fault led to
tripping of Units
64/I/2 Complete outage of North Chennai TPS
STG-2
25-04-2017
at 18:27hrs
Tripping of evacuating lines due to fault led to
tripping of Unit
Pending
[with TANTRANSCO]
Complete outage of North Chennai TPS
STG-2
Tripping of evacuating lines due to fault led to
tripping of running Unit at NCTPS Stg-2
26-03-2017
at 21:09 hrs
TANTRANSCO and PGCIL (SR-II) to take steps to complete insulator
replacement works on the 400 kV lines owned by them in Chennai area
within 3 months.
Status received vide TANTRANSCO mail dated 15-06-2017 &
04.08.2017 & 18.09.2017 & 12-12-2017:
1. All the Porcelain insulators of 400kV NCTPS-II - Vallur feeders-1&2
were replaced with Polymer insulators by 20.05.2017. -----
Completed
2. Existing Porcelain insulators of all other 400kV feeders are being
replaced with Polymer insulators in a phased manner.
--- Pending
PGCIL (SR-II) Mail dated 11-12-2017:
Pertaining to POWERGRID all the porceleing insulators in the polluted
streches has been completed. - Completed.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that a total of 597 insulators ahd alreeady been
replaced, and the total replacement would take another 9-month
period.
In this regard, TANTRANSCO was asked to furnish detailed plan of action
regarding replacement of insulators on all 400 kV lines owned by them in
Chennai area.
TANTRANSCO/
PGCIL(SR-II)
TPCIL to complete procurement of LDP relays. To this, PCSC forum asked
TPCIL to submit written confirmation to PGCIL (SR-I) by 29.12.2017.
PGCIL (SR-I) assured that with receipt of above confirmation from TPCIL
by Dec, 2017, they would be able to complete the work by FEbruary,
2018.
APTRANSCO informed that they would be able to implement LDP from
their & APGENCO side by April, 2018.
In this regard, PCSC forum made it clear that the recommendation is
about providing LDP as both Main-I & Main-II relays on all stated lines in
Nellore Complex, ans asked all stakeholders to ensure & comply with the
same.
64/I/3
PendingPGCIL (SR-I) Mail dated 15-12-2017:
On 30.11.2017 Line S/D availed by TS TRANSCO. PGCIl end Main-1 & 2
relays were tested. Main-2 relay REL 100, make ABB was not working.
Same has been informed to TSTRANSCO for replacement of faulty relay.
Review Meeting dated 19.12.2017:
After considering issues narrated by PGCIL (SR-I) and TSTRANSCO, the
following were decided:
(i) PGCIL (SR-I) would look into DC leakage related issues at their 400 kV
Ghanapur SS, and rectify the same, if any, by second week of January,
2018.
(ii) TSTRANSCO would arrange for testing of PLCC equipment & panels by
their OEM (ABB) and get the issues sorted out in coordination with PGCIL
(SR-I) by 20.01.2018.
PGCIL (SR-I)/
TSTRANSCO
Tripping of 400 kV Ghanapur-Mamidapalli
line
64/III/2 For the line under consideration, PGCIL (SR-I)/ TSTRANSCO to (i) rectify
issues w.r.t. PLCC channels, (ii) restore PLCC carrier communication, and
(iii) put A/R into service at the earliest.
B-phase to earth fault. Line auto-reclosed from
Mamidapalli end and tripped from Ghanapur
04-04-2017
at 19:01hrs
Annexure-III
Page 7 of 37
Pending05-06-2017 at
19:15 hrs
For the line under consideration, the following shall be carried out by
TSTRANSCO in coordination with PGCIL (SR-I):
(i). End-to-end communication for DT/ permissive & other signals may
be ensured by testing at both the ends.
(ii). Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
TSTRANSCO/
PGCIL (SR-I)
PGCIL (SR-I) Mail dated 15-12-2017:
On 30.11.2017 Line S/D availed by TS TRANSCO. PGCIl end Main-1 & 2
relays were tested. Main-2 relay REL 100 make ABB was not working
same has been informed to TSTRANSCO for replacement of faulty relay.
Review Meeting dated 19.12.2017:
After considering issues narrated by PGCIL (SR-I) and TSTRANSCO, the
following were decided:
(i) PGCIL (SR-I) would look into DC leakage related issues at their 400 kV
Ghanapur SS, and rectify the same, if any, by second week of January,
2018.
(ii) TSTRANSCO would arrange for testing of PLCC equipment & panels by
their OEM (ABB) and get the issues sorted out in coordination with PGCIL
(SR-I) by 20.01.2018.
Tripping of 400 kV Ramagundam -
Dichipally line, 400kV Nizamabad -
Dichipally line-1 and 400/220 kV ICT-1
Line tripped at Ghanapur end only and was holding
from Mamidapalli. Ghanapur end protection had
sensed R-phase to earth fault
1. TSTRANSCO/ NTPC to adopt proper Zone-2 time settings (say,
Ramagundam end --> 500 msec; Dichipally end --> 350 msec in line with
Ramakrishna Committee recommendations) on 400 kV Ramagundam –
Dichipally line and 400 kV Dichipally - Nizamabad lines respectively.
2. For the 400 kV Dichipally - Nizamabad D/C line, TSTRANSCO, in
coordination with PGCIL (SR-I), to carry out the following:
(i) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(ii) Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
NTPC-Ramagundam/
TSTRANSCO/
PGCIL (SR-I)
PGCIL (SR-I) Mail dated 15-12-2017:
1. In 400kV Nizamabad-Dichpally lines Zone-2 trip time delay of 0.35 sec
was already implemented at Nizamabad end.
2. For 400kV NZB-Dichpally D/C lines PLCC commissioned with LDP relays
& Line-1 tested on 16.09.2017 & Line-2 tested on 17.09.2017 found ok. --
- Completed
Review Meeting dated 19.12.2017:
1. It was agreed that TSTRANSCO would provide revised settings to NTPC-
Ramagundam for implementation in one-week time.
In this regard, PCSC forum also asked TSTRANSCO to revise their Zone-2
settings of their 220 kV & 400 kV lines in line with Ramakrishna
Committee guidelines. To this, TSTRANSCO replied in affirmative and
assured that they would comply with the same by January, 2018.
66/ II/ 5
65/II/5 Tripping of 400 kV Ghanapur-Mamidapalli
line
08-05-2017 at
19:15 hrs
Triggering incident was fault in 400kV Nizamabad
GIS
Pending
Annexure-III
Page 8 of 37
TSGENCO/
PGCIL (SR-I)
Lines – 1 & 2 tripped on B-phase to earth faults
We communicated to M/s Siemens to upgrade the firmware version
regarding adaptive dead time.
Hence, it is requested to review these settings to reduce the stress on
Generating Station --- Completed
Review Meeting dated 19.12.2017:
2. It was made clear to PGCIL (SR-I) that this is a specific case of those
400 kV lines where one one of the ends is a generating station, and the
other end is grid-connected substation having TOR feature in line
protection relays. The said recommendation of enabling TOR along with
sending DT to the other end is basically to ensure safety of Generating
Units at the other end. Accordingly, PGCIL (SR-I) was asked to take steps
to ensure the same. --- Pending
4. PGCIL (SR-I) informed that shutdown was availed by TSGENCO on
14.12.2017, and all issues relating to PLCC including end-to-end testing
were carried out. --- Completed
08-06-2017 at
18:32 hrs
66/ II/ 8 Tripping of 400 kV Khammam – KTPS lines
– 1 & 2
Pending
[with
PGCIL (SR-I)]
1. --- Pending with TSGENCO
PGCIL (SR-I) Mail dated 15-12-2017:
2). TOR feature in MiCOM P444 relay enabled for 400kV KMM-KTPS lines
at Khammam end. DT send on TOR trip is not as per protection
philosopy. However if SRPC/SRLDC gives separate instructions
exclusively for this line, the same shall be imoplemented after getting
our CC approval. --- Pending
3). At Khammam SS all DR & ELs are time synched. --- Completed.
4). --- Pending
TSGENCO Mail dated 18.12.2017:
1). If the auto reclose function dead time kept same at both ends as 1
sec uniformly. In case of persistent fault, it leads to feed the fault from
both ends and cause the generator breaker switching on to high fault
current and chances of pole slip. To avoid this time differentiated A/R
scheme to be implemented. In KTPS 400KV Line –I & II at KTPS end
dead time is 1.2sec and at KMM end it is 1sec.
In our relay 7SA522 does not have the adaptive dead time function A/R.
Hence, it is requested to send DT in case of on 3-phase trip and A/R
unsuccessful at KMM end to avoid reclose attempt from KTPS end after
dead time (1.2Sec) for persistent faults.
1. TSGENCO to keep uniform A/R dead-time of 1 sec on the lines
emanating from their KPTS station.
2. PGCIL (SR-I) to enable Trip-on-Reclose (TOR) functionality for Zone-2
faults for Khammam – KTPS lines at Khammam end, if such a feature is
available in the concerned relay, and to configure it for sending Direct
Trip (DT) Command to KTPS end.
3. PGCIL (SR-I) to set right time-sync issues w.r.t. Khammam end Event
Loggers on Khammam – KTPS lines.
4. For 400 kV Khammam – KTPS line-1, PGCIL (SR-I), in coordination with
TSGENCO, shall carry out the following:
(i) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(ii) Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
Annexure-III
Page 9 of 37
Tripping of 400/ 220 kV ICT’s – 3 & 4 at
Ramagundam STPS
1. NTECL to ensure time sync of Protection Relays with GPS at their
Vallur TPS.
2.TANGEDCO to review retaining blind-zone for the Tie-CB (408) in
consultation with its OEM.
R-phase to ground fault occurred in 400kV NCTPS –
Manali line. Busbar protection of 400 kV Bus-1 got
operated at NCTPS-II.
68/I/2 Complete outage of 220 kV Kadra Power
Station of KPCL.
1. KPCL to investigate the reasons for non-tripping of 220 kV Kadra –
Kodasalli line from Kadra end by any of the Main protection relays, and
opening of only B-ph pole at Kodasalli end, and furnish an action taken
report on the same.
2.KPCL to sort out issues relating to downloading of DR’s & EL’s at Kadra
PH at the earliest.
3. KPCL to use both the 220 kV buses as main buses under normal
operation, and to go for single bus operation only during emergencies at
their Kadra PH.
4. NPCIL (KGS) to configure time resolution of Event Loggers to mill
seconds at their Kaiga GS.
Triggering incident was tripping of 220 kV Kadra-
Kodasalli and 220 kV Kadra-Kaiga line. There was no
generation at Kadra in antecedent condition.
KPCL/ NPCIL (KGS) 1. --- Pending
2. --- Pending
3. --- Pending
Status received vide NPCIL mail dated 29-11-2017:
4. The event logger(ESCADA) has inherent time resolution of 10
millisecond for digital inputs. In future higesht resultion event logger
history will be extratced for submission to grid authorities..--NPCIL-
KAIGA ----Completed
Review Meeting dated 19.12.2017:
1). Kadra-kaiga 220KV line tripped on both end in Zone-1 distance
protection. Fault distance is 0.9KM from kadra end. Kodasalli-Kadra
220KV tripped at Kodasalli end only in Zone-1 fault. Reason for tripping is
the both Kadra-kodasalli, kadra-Kaiga line are in same tower, hence
same fault reflected adjuscent line. Because of no Bus source, Kadra end
relay stopped to detect, hence Kadra end breaker was intact.
---- Completed
2). Issue relating to downloading of DRs & Els at Kadra PH rectified. ---
Completed
3). KPCL informed that they have planned to take up providing double-
bus operation at their 220 kV Kadra PH, 220 kV Gersoppa PH, and 220 kV
Raichur TPS through PSDF funding, and DPR for the same is under
preparation. After obtaining approval of the same from their
management, other activities inluding tenders floating, approaching
PSDF would be taken up. All these activites are targeted to be completed
within 2 years.
--- Pending
Status received vide NTECL mails dated 29-11-2017:
1. Time synchronisation is ensured for all relays for the six outgoing lines
at NTECL end. ----Completed
Status received vide TANGEDCO mails dated 13-12-2017:
2. Tie CB (408) of Manali feeder got tripped for line fault.The Main
CB(409) of Manali feeder was not in service at the time of above
occurrence and isolated from service for Maintenance works. During the
above occurrence, Bus bar protection was also operated and Bus-1 got
isolated due to contamination of SF6 at the Main CB(407) of Vallur II
feeder.Blind Zone Reviewed for Main CB (407) and retained. Also blind
zone enabled condition for all Main CB's.Tie CB's not covered in the Bus
bar protection scheme. --- Pending
Review Meeting dated 19.12.2017:
Since the recommendation pertains to Tie-CB (408), TANGEDCO was
asked to look into the same and reply appropriately.
Tripping of 400 kV NCTPS – Vallur-2 and
NCTPS-Manali lines
66/ II/ 10
NTECL/ TANGEDCO67/II/13 04-08-2017 at
02:01 hrs
Pending
[with TANGEDCO]
25-09-2017
at 11:41hrs
PendingNTPC mail dated 07.12.2017:
1. High set DEFR on 220 KV lines is disabled ----Completed
2. ---- Pending
Review Meeting dated 19.12.2017:
TSTRANSCO informed that the works are under progress, and are
targeted to be completed in 3 months time.
NTPC-Ramagundam/
TSTRANSCO
Pending
11-06-2017
at 19:46hrs
1. NTPC to disable high-set of DEFR on the 220 kV lines emanating from
their Ramagundam STPS.
2. NTPC/ TSTRANSCO to provide Line Differential Protection (with or
without pilot) on 220 kV Ramagundam – Malayalapalli lines – 1 & 2 & 3.
Triggering incident was failure of 220 kV
B-phase LA in ICT-3 LV extension feeder (220KV line-
2) at Malayalapalli substation
Annexure-III
Page 10 of 37
69/II/10 Tripping of 400 kV Hassan-UPCL line-1&2 13-10-2017 at
16:11 hrs
R-Y phase to earth fault in line-1 and R-phase to
earth fault had occurred simultaneously in Line-1 &
line-2 respectively. Line-1 got tripped due to LLG
fault. In Line-2, auto-reclose was successful at
Hassan and 3-phase trip at UPCL.
For the line trippings under consideration, PGCIL (SR-II) and UPCL to
furnish relevant COMTRADE (.cfg & .dat) files to PCSC forum so that the
same could be analysed using PSCT software by PRDC for correct
operation of the relays involved.
PGCIL (SR-II)/ UPCL Yet to be informed Pending
1. TPCIL to configure DEF protection such that it remains in blocked
condition as long as Distance Protection is active, and becomes active
only when distance protection does not pickup.
2.PGCIL (SR-I) to ensure healthiness of Carrier communication, and the
set PUP mode of carrier aided scheme operates reliably on TPCIL lines 1
& 2.
30-10-2017 at
21:37 hrs
400kV TPCIL - Nellore line-1 got tripped at TPCIL end
during failure of LA of Station Transformer-2 at
TPCIL. Running Units at TPCIL got tripped due to loss
of evacuating line. 400kV TPCIL - Nellore PS line-2
was under emergency shutdown
69/III/3
69/I/2
Tripping of 400 kV Kurnool(PG) –
Kurnool(AP) line-2
Tripping of 220 kV Ragulapadu – Alipura
line
TPCIL/ PGCIL (SR-I)Complete outage of 400kV TPCIL station
PendingAPTRANSCO maild ated 15.12.2017:
APTRANSCO would extend support and requirements if any ,for the
rectification proposed by KPTCL.
Review Meeting dated 19.12.2017:
It was noted that the original Gooty - Lingapur line got LILOed at BTPS,
Alipura, and Ragulapadu. It was also noted that Phase Discrepancy is
being observed in Ragulapadu - Alipira section only. When enquired
about the same, KPTCL informed that they would examine the issue in
detail, and would inform the action lan proposed by next PCSC-71
meeting. On this, APTRANSCO was also asked to render all help required
from their side to KPTCL.
Pending
Review Meeting dated 19.12.2017:
PGCIL (SR-I) informed that they are waiting for written confirmation from
TPCIL to complete procurement of LDP relays. To this, PCSC forum asked
TPCIL to submit written confirmation to PGCIL (SR-I) by 29.12.2017.
PGCIL (SR-I) assured that with receipt of above confirmation from TPCIL
by Dec, 2017, they would be able to complete the work by February,
2018.
APTRANSCO informed that they would be able to implement LDP from
their & APGENCO side by April, 2018.
In this regard, PCSC forum made it clear that the recommendation is
about providing LDP as both Main-I & Main-II relays on all stated lines in
Nellore Complex, ans asked all stakeholders to ensure & comply with the
same.
Pending
Yet to be informed
APTRANSCO/ KPTCLKPTCL and APTRANSCO to sort out issues relating to incongruence in
denoting R, Y, B phases of the electric supply on their respective sides.
Line tripped on B-Ph to earth fault. A/R was
successful at Regulapadu and breakers at Alipura
end got tripped.
1) PGCIL (SR-I) and APTRANSCO to provide for Line Differential
Protection as both the Main protections on 400 kV Kurnool (AP) –
Kurnool (PG) lines 1 & 2 lines.
2) APTRANSCO to furnish an action taken report w.r.t. resolving A/R non-
operation at Kurnool-AP end for the subject trippings and configure EL
for capturing PDR operation at their 400 kV Kurnool-AP SS.
Line tripped on B-ph to ground fault. A/R was
unsuccessful at both Kurnool (AP) and Kurnool (PG)
ends.
APTRANSCO/
PGCIL (SR-I)
02-10-2017 at
02:03 hrs
12-10-2017 at
01:30 hrs
69/III/7
70/IV/3 Tripping of 400 kV Ramagundam - Gajwel
line
21-11-2017 at
17:17 hrs
Line tripped on direct Trip receive indications at
Gajwel end only and was in service from
Ramagundam
For the line under consideration, the following shall be carried out by
TSTRANSCO in coordination with NTPC-Ramagundam:
(i) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(ii) Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
TSTRANSCO/NTPC-
Ramagundam
Yet to be informed Pending
Annexure-III
Page 11 of 37
69/II/7 Tripping of 400 kV Uravakonda –
Jamalamadugu line-1
06-10-2017 at
10:22 hrs
Line tripped on overvoltage at Uravakonda end and
Direct Trip received at Jamalamadugu end. DR & EL
of Uravakonda end not furnished.
APTRANSCO to complete configuration of DR’s & EL’s for all protections
relays at their 400 kV Uravakonda SS, and render them suitable for
extraction/downloading of relevant tripping records/ events within a
month’s time.
APTRANSCO APTRANSCO Mail dated 15.12.2017 & Review Meeting dated
19.12.2017:
Instructions were issued for taking necessary action.
Pending
1.APGENCO to furnish compliance report on the recommendations given
by PSAG-9 team that had visited Srisailam RB PH on 14-15 October,
2014.
2.APGENCO to carry out the following:
(i)Removal of DC earth leakage in station switchyard on priority basis
(latest by 10.12.2017)
(ii)Integration of Station earth-mat and Switchyard earth-mat.
3. APGENCO to provide for numerical relays (as both Main-I & Main-II)
on all 220 kV feeders emanating from Srisailam RB PH.
4.APGENCO to put A/R into service on all 220 kV feeders emanating from
Srisailam RB PH.
5.APGENCO to provide for Time Synchronization equipment at their
Srisailam RB PH to synchronize all protection relays with GPS.
Yet to be informed220kV Srisailam RB – Markapuram S/C line and 220
kV Srisailam – Podili S/C line tripped on operation of
distance protection. Srisailam Units - 3, 4, 6 and 7
got tripped during the incident.
Pending
Tripping of 400 kV Nellore (PG) - NPS line-
1, 400 kV Krishnapatnam-Nellore (AP) lines -
1&2 and 400kV NPS - MEPL line
Review Meeting dated 19.12.2017:
It was noted that no APGENCO representative had come to attend the
meeting.
APGENCO Mail dated 19.12.2017:
Procurement of relays is under progress
68/III/9
APGENCO
Complete outage of 220 kV Yerraguntla
substation and tripping of running Units at
Rayalaseema TPS
52/I/2 (GD) PendingMail received on 27-07-2016:
1.The drop out relays of reducer oil pumps time setting was increased
for all mills.So there will not be any trip under transient low voltage
condition.----Complied
2.The recommendation regarding 2 sec time delay will be implemented
during unit shut down and will be intimated immediately after
implementation.------Pending
Review Meeting dated 19.12.2017:
It was noted that no APGENCO representative had come to attend the
meeting.
APGENCO 1. APGENCO to check associated logic for lube oil pump for correct
operation under transient low voltage conditions at Rayalaseema TPS,
Unit-1.
2. APGENCO to keep appropriate time delay/ fault ride through delay
(typically 2 sec) in VFD speed sensor relay at all its generating Units
including Rayalaseema TPS Units.
HV B-Ph Current transformer of 100MVA Power
Transformer -1 failed resulting into a bus fault on
220KV Bus-1. Unit-1 and Unit-5 at RYTPS tripped
during the fault at Yerraguntla substation
21-02-2016 at
10:39 hrs
Andhra Pradesh
Pending
Pending
For the subject line relay at Kalpaka end, APTRANSCO to configure DR for
a post-triggering period of 2 sec and EL for all required protection
(analog & digital) events
Y-phase to earth fault. Auto – reclose was stated to
be successful at Kalpaka end. At Asupaka end Auto-
reclose had not operated due to problem in
configuration settings.
APGENCO to furnish a report on the remedial action implemented w.r.t.
overreaching of Krishnapatnam end distance relays during the tripping
of 400 kV Nellore (PG) - NPS line-1
APGENCOTriggering incident was snapping of Y phase
conductor in 400kV Nellore (PG) - NPS line-1.
Distance relay at Krishnapatnam end over-reached
in Zone-1, and resulted in tripping of 400kV
Krishnapatnam – Nellore (AP) lines - 1&2 from
Krishnapatnam end. Distance relay at MEPL over-
reached and resulted in tripping of MEPL-NPS line
from MEPL end.
APTRANSCO
09-10-2017 at
14:39 hrs
29-09-2017 at
10:48 hrs
18-07-2016
at 19:05 hrs
APTRANSCO Mail dated 15.12.2017:
Post triggering period of 2 see for DR is configured. Wiring under the
scope of retrofitting works is being carryout by EMC. EL will be
configured on completion to wiring works.
Review Meeting dated 19.12.2017:
APTRANSCO informed that the recommedned works would be
completed by 31.01.2018.
Multiple trippings at Tripping at 220 kV
Srisailam Right Bank power station
69/II/1
Tripping of 400 kV Kalpaka – Asupaka line
57/II/9
Annexure-III
Page 12 of 37
07-11-2017 at
23:02 hrs
09-11-2017 at
21:57 hrs
12-11-2017 at
20:54 hrs
17-11-2017 at
21:19 hrs
11-11-2017 at
22:02 hrs
12-11-2017 at
23:09 hrs
24-11-2017 at
18:46 hrs
Telangana
Pending
TSGENCO TSGENCO mail dated 30.03.2017:
1. According to SRPC phylosphy power swing block settings are changed
to ALL ZONES BLOCK EXCEPT ZONE1.
---------- Completed
2. M/s. Siemens is requested to depute the service Engineer to update
the firm ware of existing SIPROTEC relays in 400KV switch yard. This
work will be completed on or before 15.04.2017.
----------- Pending
TSGENCO mail dated 08.12.2017:
1. --- Completed
2. As this KTPS line-II is being LILOed at KTPS, Stage-VII, those relays
would be replaced with line diff relays. --- Pending
Review Meeting dated 19.12.2017:
As recommeded, TSGENCO was asked to migrate to new versions of
firmware in consultation with relays OEM.
------- Pending
Pending
Pending
1. TSGENCO to implement the SRPC agreed philosophy for Power Swing
Blocking in all distance relays on the feeders emanating from KTPS.
2. For the line under consideration, TSGENCO to consult relays OEM to
migrate to new versions of Firmware (from 4.68.03 to 4.72.01) and Pset
(from 4.63.04 to 4.70.02).
TSGENCO Yet to be informed
Yet to be informedTSGENCOTSGENCO to adopt stipulated OVR, Stage-I gradings for the 400 kV lines
emanating from their 400 kV Srisailam LB RH, and furnish an action
taken report w.r.t. mitigating observed voltage difference among R & Y
& B phases
Line tripped on operation of Over-Voltage
protection at Srisailam and Direct Trip was received
at Kurnool. Considerable voltage difference was
observed between R, Y & B phases.
Line tripped on operation of over-voltage protection
at Srisailam and Direct Trip was received at
Sattenapalli. Considerable voltage difference was
observed between R, Y & B phases at Srisailam end.
Tripping of 400kV Kurnool-Srisailam line
TSGENCO to adopt stipulated OVR, Stage-I gradings for the 400 kV lines
emanating from their 400 kV Srisailam LB RH, and furnish an action
taken report w.r.t. mitigating observed voltage difference among R & Y
& B phases.
61/III/5 24-12-2016 at
10:52 hrs
Tripping of 400 kV Khammam - KTPS line-2 Line tripped on B-phase to earth fault. First fault was
persistent for 380 ms. Auto-reclose was successful at
Khammam end during 1st fault. 2nd fault occurred
during re-claim time of breaker hence Khammam
end breakers also got tripped.
70/II/3 Tripping of 400 kV Satenapalli-Srisailam
line-1
70/II/2
Annexure-III
Page 13 of 37
69/III/1 Tripping of 400 kV Gajwel - Narsarpur line 01-10-2017 at
03:55 hrs
Tripped on B-phase to earth fault. Auto-reclose
attempt could not be validated with submitted DR
of both ends and from PMU data plot.
TSTRANSCO to configure DR’s and EL’s of Protection relays at their 400
kV Gajwel SS and 400 kV Narsapur SS for proper time-scales and for
recording all required protection events.
TSTRANSCO Yet to be informed Pending
69/III/4 Tripping of 400 kV Suryapet –
Shankarapally line-2
06-10-2017 at
21:47 hrs
Tripped on B-Phase to ground fault. A/R acted and
unsuccessful at Suryapet end and A/R did not
operate at Shankarapally end.
TSTRANSCO to configure DR’s and EL’s of Protection relays at their 400
kV Suryapet SS and
400 kV Shanakarapally SS for proper time-scales and for recording all
required protection events
TSTRANSCO Yet to be informed Pending
70/II/10 Multiple trippings at 220 kV Hyderabad
(Ghanapur) Substation
30-11-2017 at
12:02 hrs
All elements connected to 220 kV Bus-2 got tripped
due to operation of Bus-bar protection during fault
in 220 kV Ghanapur-Hayathnagar line-2
TSTRANSCO to change star-point earthing of busbar core CT secondary
of ICTs – 1 & 4 from the switchyard to the Control Room Panel, and then
take appropriate measures to ensure earth-mat integrity at their 220 kV
Ghanapur SS.
TSTRANSCO Yet to be informed Pending
59/IV/3 For the line under consideration, the following shall be carried out by
TSTRANSCO in coordination with PGCIL (SR-I):
(i) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(ii) Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
Pending
Pending
TSTRANSCO mail dated on 21-12-2016:
(i) Letter is been given to field for conducting end to end testing of
400kV Gajwel-Ghanapur line.
(ii) Healthiness of PLCC system components will be checked while
conducting end to end testing.
TSTRANSCO mail dated on 31-05-2017:
Letter is been given to field for conducting end to end testing of 400kV
Gajwel-Ghanapur line.
Review Meeting dated 19.12.2017:
TSTRANSCO informed that PLCC end-to-end testing would be carried out
on 20.12.2017.
TSTRANSCO
1. For the line under consideration, TSTRANSCO to sort-out A/R related
issues at Gajwel end.
2. For the line under consideration, TSTRANSCO to configure EL at
Gajwel such that PDR operation is also captured in it.
3. TSTRANSCO to configure DR’s of protection relays at their Gajwel SS
for a post-triggering period of 2 sec so as to capture complete A/R
operation.
67/III/1 Tripping of 400 kV Gajwel - Bhoopalapalli
line
06-10-2016 at
12:16 hrs
Tripping of 400 kV Gaiwel-Hyderabad line line tripped on direct trip receive at Gajwel and was
holding from Hyderabad
22-07-2017 at
13:13 hrs
Line tripped on B-ph to earth fault. Auto-reclose was
successful at Bhoopalapally end and breaker tripped
at Gajwel.
TSTRANSCO Review Meeting dated 19.12.2017:
1) & 2) & 3) TSTRANSCO informed that given reocmmendations would be
complied with by 10.01.2018
Annexure-III
Page 14 of 37
PAR/
PCSC-58
TSTRANSCO mail dated on 31-05-2017:
1. Letter is been given to field for conducting end to end testing of
400kV Gajwel-Bhoopalpalli-1 line --- Pending
TSGENCO mail dated 08.12.2017 & 19.12.2017:
TSGENCO/KTPP will make all the necessary arrangements for checking
the end to end protection through communication system prior to
intimation by TSTRANSCO --- Pending
Review Meeting dated 19.12.2017:
TSTRANSCO informed that PLCC end-to-end testing would be carried out
as recommended by 10.01.2018.
TSGENCO /
TSTRANSCO
For the line under consideration, TSTRANSCO to carry out the following
in coordination with TSGENCO:
(i) Healthiness of PLCC system components (hardware and software) at
both ends shall be checked and faulty components shall be repaired/
replaced.
(ii) End-to-end communication for DT/ permissive & other signals may be
ensured by testing at both the ends.
(iii) Frequency bandwidth tuning of PLCC link for faithful transmission of
signals shall be carried out.
PendingTSGENCO/
TSTRANSCO
Provision of line differential protection for Jurala line 1 & 2 (line length-1.45 KM) feeders at 220 kV Jurala HPS
[Carry-Over from Protection Audit Recommendations]
62/IV/5 Pending
The issue was discussed in PCSC-58 meeting held on 18.10.2016, when
PCSC forum agreed to de-link the implementation of the Item from the
scope of Protection Audit Recommendations (PAR), and pursue it as
part of PCSC Recommendations.
TSGENCO mail dated 30-05-2017
Procurement of Differential Protection relays is under process and the
work will be completed by the end of November 2017.
TSGENCO mail dated 18-09-2017
Procurement of Line Differential Protection Relays is under process and
the work will be completed by the end of January 2018.
Review Meeting dated 19.12.2017:
TSGENCO informed that they are in constant touch with TSTRANSCO in
this regard, and hope to implement LDP by February, 2018.
TSTRANSCO informed that procurement of LDP relays is under progress,
and assured that LDP would be implemented in 3-months time.
Line tripped at Bhoopalapally on DT receive and was
holding from Gajwel.
Tripping of 400 kV Gajwel-Bhoopalapalli
line-1
16-02-2017
at 15:00 hrs
Annexure-III
Page 15 of 37
Pending
Status received vide KPCL mail dated 14.12.2017:
3) DPR for implementation of Two Bus operation for 220kV bus system
has been prepared and proposal is placed for funds from PSDF. After the
approval of the DPR, the work is proposed to be taken up.
Review Meeting dated 19.12.2017:
3) KPCL informed that DPR for implementation of Two Bus operation for
220kV bus system has been prepared and proposal is placed for funds
from PSDF. After the approval of the DPR, the work is proposed to be
taken up. Time frame requested for is 2 yrs.
KPCL1. KPCL to check the operation of anti-pumping relay on 220 kV side and
keep it in healthy condition.
2. KPCL to provide manual reset to the 220 kV side master trip relay.
3. KPCL to use both the 220 kV buses as main buses under normal
operation, and should go for single bus operation only during
emergencies.
07-06-2015 at
01:35 hrs
Triggering incident was B-phase to earth fault had
occurred in 220kV Kadra-Kodasalli line. Line tripped
from Kodasalli end only. 220kV Kaiga-Kadra tripped
in Zone-3 from Kaiga end. Tripping of evacuating
lines caused bus shut down at Kadra hydro station.
16-02-2015 at
12:56 hrs
Mail received on 28-05-2015:
1. Main-2 relays already installed and commissioned.
2. DC fuses are intact. Till date no such incidence occurred.
3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be
reviewed.
Mail received on 07-07-2015 , 21-10-2015 and 23-11-2015:
1. --- Completed.
2. --- Completed.
3. Possibility of DC-1 & DC-2 arrangement and splitting of DC will be
reviewed --- Pending
Status received vide KPCL mail dated 14.06.2017:
3. Providing 2 separate DC sources is under process --- Pending
Status received vide KPCL mail dated 14.12.2017:
3. Work under implementation stage --- Pending
Review Meeting dated 19.12.2017:
3. KPCL informed that for providing 2 separate DC sources with new
battery charger, LOA & Work order were placed on M/s Eltek Power
system. The works would be completed in March, 2018. --- Pending
Pending41/I/1
46/II/21
KPCL
Mail received on 21-10-2015:
1) Anti-pumping contactors of all the nine 220KV Lines are in circuit and
tested periodically during AOH works of lines along with other
protections.
2) Completed.
3) Possibility to use both the 220kV buses as main bus under normal
operation is under review.
Mail recieved on 23-11-2015:
1) Completed
3) Two bus operation for 220kV buses : In place of existing CT switching
relays, High speed manual heavy duty change over switch of sufficient
current capacity will be retrofitted to all feeders at 220kV station and
same will be operated manually during changeover of feeder by one bus
to the other and this arrangement may facilitate to put both buses in
service. Time required for this retrofit is around 90days . However, this
work will be taken up only after retrofitting of electromagnetic relays
with numerical relays for Main-2 protection of all 220kV lines, for which
work is in progress.
Status received vide mail dated 10-07-2017:
1) --- Completed.
2) --- Completed.
3) Two Bus operation for 220kV bus is being carried out whenever
required. However scheme for tripping of one bus during LBB/fault and
maintaining the other bus intact by tripping B/C breaker will be taken up
in R&M works. --- Pending
1. KPCL to make functional the Main2 (EPAC) relay with the help of
KPTCL at the earliest.
2. KPCL to investigate the reason for DC fuse fail during transient fault
in 220kV Kadra-Kodasalli line including the testing/ checking of DC
supply cables, breaker control cables, and trip coils.
3. KPCL to ensure supply for Main-1& Main-2 protections, Trip Coils
(TC1, TC2) from separate battery banks.
Karnataka
Trippings at 220kV Raichur TPS
GD-1 at 220kV Kadra power Station of
KPCL
Annexure-III
Page 16 of 37
Tripping of Units at 220 kV Raichur TPS In view of the availability of two buses along with healthy bus-coupler at
220 kV RTPS, KPCL is recommended to put in service the double-bus
operation at 220 kV RTPS by suitably distributing loads within 15 days.
1.KPCL to undertake the following remedial measures to avoid breaker
flashovers:
(i) Replacing all porcelain insulators with composite insulators
(ii) Carrying out hot-line water washing of all insulators on regular basis.
(iii) Applying Room Temperature Vulcanizing (RTV) Silicone high voltage
insulator coatings to all bus-connected ceramic insulators of equipment
like CT, PT, CB, Isolators etc.
2.KPCL to take steps to provide dedicated breaker flashover protection
to all breakers at Raichur TPS at the earliest.
Y-ph Pole of Tie-breaker of Unit-4 at RTPS failed.
Unit-4 got tripped on operation of Generator
Differential, Reverse power & LBB protection.
Operation of LBB protection led to tripping of BUS-2
at RTPS
Pending
Review Meeting dated 19.12.2017:
1 (iii) As upgradation of 400kV switchyard equip's to be taken under
PSDF funds, Silicon rubber coating for breakers is deffered till then. ---
Pending
2. Replacement by Num relay for Units - 5,6 & 7 completed in the month
of Oct-2017. Main-I is Seimens make and Main-II is ABB make. ---
Pending
KPCL Status received vide KPCL mail dated 10.07.2017:
1. (ii) Hot line water washing stopped and off line water washing is
carried out whenever the 400 KV Unit or line is under tripped condition /
Shutdown condition. --- Completed
1. (iii) Silicon coating for Unit#8 main & tie breakers carried out in Sep'16
and same is under observation. Till today in order and good condition.
For remaining breakers, since it is big order, approval for the same is
under process. --- Pending
2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker
flash over protection feature will be enabled (if available) in the
numerical relays which will be retrofitted in phased manner during R&M
works.
Status received vide KPCL mail dated 14.12.2017:
1.(i) --- Pending
1. (ii) Hot line water washing stopped and off line water washing is
carried out whenever the 400 KV Unit or line is under tripped condition /
Shutdown condition. --- Completed
1. (iii) Silicon coating for Unit#8 main & tie breakers carried out in Sep'16
and same is under observation. Till today in order and good condition.
For remaining breakers, since it is big order, approval for the same is
under process --- Pending
2. Static / Electromechanical relays are existing in all 1 to 7 units. Breaker
flash over protection feature will be enabled (if available) in the
numerical relays which will be retrofitted in phased manner during R&M
works --- Pending
.
Status received vide KPCL mail dated 10.07.2017:
The electro-mechanical back-up impedance protection relay is in service.
However, Budgetary offer obtained for the retrofitting of Line reactor
protection with Numerical relay and is under process
Status received vide KPCL mail dated 14.12.2017:
Tendering under process
Review Meeting dated 19.12.2017:
KPCL informed that the new numerical relay for backup impedance
protection of Line Reactor would be provided by June, 2018.
Pending
PendingStatus received vide KPCL mail dated 10.07.2017 & 14.12.2017:
Two Bus operation for 220kV bus is being carried out whenever required.
However scheme for tripping of one bus during LBB/fault and
maintaining the other bus intact by tripping B/C breaker will be taken up
in R&M works.
Review Meeting dated 19.12.2017:
3) KPCL informed that DPR for implementation of Two Bus operation for
220kV bus system has been prepared and proposal is placed for funds
from PSDF. After the approval of the DPR, the work is proposed to be
taken up. Time frame requested is 2 yrs.
54/II/13
KPCL to keep the functioning of the concerned electro-mechanical back-
up impedance protection relay under observation, and replace it with a
spare at the earliest.
Tripping of 400 kV Raichur TPS-
Mahboobnagar line
05-04-2016 at
10:23 hrs
Line tripped on operation of Backup impedance
protection of line reactor. Direct trip was received at
Mahboobnagar end.
KPCL
54/II/9
15-04-2016 at
15:36 hrs
KPCLDuring testing of retrofitted distance protection in
400kV Raichur-2 feeder, LBB protection trip DC got
extended to Bus trip. This resulted in tripping of
220kV bus at RTPS and all connected 220 kV
elements. Unit-4 which is connected to 400 kV Bus
got tripped due to tripping of Station Utility
Transformer that is connected 220 kV bus
54/II/4
Tripping of 400kV Raichur TPS
Bus-2
13-04-2016 at
21:12 hrs
Annexure-III
Page 17 of 37
Pending
KPCL1.KPCL to enable zero-sequence compensation feature, if not already
done, in all differential relays of transformers at RTPS.
2.KPCL to examine in detail the reasons for SOTF operation at RTPS end
for the fault on RTPS-Veltoor line, and if required relay (configuration)
settings at RTPS end may be suitably got revised with the help of their
OEM.
3.KPCL to take steps to enable auto-reclose for the Tie-CB’s in the dias
containing Munirabad and Veltoor (Mehboobnagar) at RTPS.
Triggering incident was failure of R-phase CT of
400/220kV ICT-1. 400kV YTPS-RTPS line got tripped
from YTPS end. 400kV RTPS-Mehaboobnagar line
tripped on a B-phase to earth fault.
Pending
Status received vide mail dated 14.06.2017:
1. Already settings are discussed with EE(RT), Hubli and soon relays will
be tested for VT fuse fail condition.
2. Timings of Zones were set as per the recommendations of CE(RT) &
R&D, KPTCL, Bangalore & EE(RT), KPTCL, Hubli.Regarding revision of
timings will be carried out in co- ordination with EE(RT), KPTCL, Hubli.
Status received vide mail dated 14.12.2017:
1. As per the recommendations of SRPC and SRLDC, in the event of VT
fuse fail, non directional over current and earth fault feature is enabled
in the distance relay with a definite time lag of 600msec on pick up and
the same is tested by KPTCL Hubli(RT) and KPCL jointly on 18.05.2017.
--- Completed
2. --- Pending
Review Meeting dated 19.12.2017:
2. KPCL informed that Zone settings of distance relays of all 220 kV lines
emanating from Magjheri SS had been revised in line with Ramakrishna
Committee guidelines.. --- Completed.
PendingKPCL
Multiple tripping at 400 kV Raichur TPS
Station
55/II/1 01-05-2016 at
21:44 Hrs
Triggering event was the fault on 220 kV Nagjheri
–Kodasalli line-2. Both buses of 220 kV Nagjeri
power station of KPCL got
de-energized.
62/I/1
Status received vide KPCL mail dated 10.07.2017 & 14.12.2017:
1) Zero-sequence compensation feature is already enabled in all the
differential relays of transformers. --- Completed
2) Referred to OEM for the tripping of line on SOTF protection.
---- Pending
3) Action has been taken to retrofit the protection relays of tie bays of
Mahbubnagar and Munirabad line to enable Auto-reclosure function. ---
Pending
Review Meeting dated 19.12.2017:
2). KPCL informed that OEM is visiting RTPS by December, 2017 for
attending the SOTF problem --- Pending
3) Action has been taken to retrofit the protection relays of tie bays of
Mahbubnagar and Munirabad line to enable Auto-reclosure function. ---
Pending
Status received vide KPCL mail dated 14.06.2017:
1. All logics checked and found normal. LBB timing checked and found
200msec as per KPTCL MRT recommendation. - Completed
2. Work Under Progress ---- Pending
3. New GPS System commissioned along with new numerical and
synchronised with GPS system - Complied
4. Work Under Progress ---- Pending
Status received vide mail dated 14.12.2017:
1),3),4) Completed
2. Auto Start of DG set is taken up --- Pending
Review Meeting dated 19.12.2017:
2. KPCL informed that for AMF of DG, Scheme prepared & material
procurement under process. The AMF scheme will be implemented in
January 2018. --- Pending
3. The GPS system commissioned on Nov 2016 & all the numarical relay
time synchronised with GPS ---- Completed
1) KPCL to check settings of LBB protection in all relays from which it was
implemented, and ensure that their configuration, logic, and timing are
in order at their 220 kV Kadra PH.
2) KPCL to furnish details regarding the existing LT auxiliary supply
arrangement at their 220 kV Kadra PH, and take steps to provide a
suitable Auto-Main-Fail (AMF) panel for DG set to effect its auto-starting
in case of failure of LT supply.
3) KPCL to ensure time-sync of all relays (DR’s & EL’s) with GPS at their
220 kV Kadra PH.
4) KPCL to provide stand-alone Event Logger at their 220 kV Nagjheri
PH.
KPCL
1. KPCL to adopt the following VT fuse-fail logic for all 220 kV lines
emanating from NPH:
“Under VT fuse fail condition, distance protection shall normally be kept
blocked. However, upon detection of a fault (sensed by negative
sequence component), blocking of distance protection shall give rise to
operation of its inherent Over-Current protection set with a definite time
delay of 500 msec”.
2. KPTCL/ KPCL to revise Zone-2, Zone-3 and Zone-4 (reverse) timings of
DPR of all 220 kV lines emanating from Nagjheri PH in line with
Ramakrishna Committee guidelines.
06-09-2016
at 14:40 hrs
Complete outage of 220 kV Nagjheri
substation of KPCL
Complete outage of 220 kV Kadra power
station of KPCL
LBB of 220kV Kodasalli breaker at Kadra end got
operated which resulted in tripping of Bus at Kadra
and in turn led to tripping of all elements
21-01-2017
at 00:38 hrs
58/I/3 (GD)
Annexure-III
Page 18 of 37
69/II/8 Tripping of 220 kV Kaiga- Kadra line-1 06-10-2017 at
22:22 hrs
While de-synchronising of Unit-2, B-phase pole of
GCB did not open and pole descrepancy relay
operated. Hence all 220KV lines CB hand tripped.
KPCL to take steps to replace the existing static protection relays for
Generator Units and Generating Transformers (GT’s) with suitable
Numerical relays at their 220 kV Kadra PH.
KPCL Yet to be informed Pending
Pending 1. KPCL to start furnishing FIR and TR of their tripping events as per the
formats provided by SRLDC.
2. KPCL to check earth-mat resistance for 400 kV switchyard and
ensure that it is within prescribed limits.
3. KPCL to set right operation of SER in C&I Control Room of Unit-4.
4. KPCL to furnish action taken w.r.t. tripping of Tie-CB of Munirabad
line on SOTF protection. OEM report, in this regard, may be furnished.
KPTCL Mail dated 16.12.2017 & Review Meeting dated 19.12.2017:
1. Recommended works at Ambewadi have not been taken up due to
various problems faced due to poor response from the turn key agency
M/s ERL. A site meeting is planned during this month to discuss about
further plan of action for attending SRPC recommendations pertaining to
the Sub station.
The issue was discussed in the review meeting. Considering the
importance of the substation and delay in executing the works, it was
decided to escalate all pending issues relating to Ambewadi SS to KPTCL
top Management for early completion.
KPTCL Pending1. Till the completion of R&M works for bus bar and LBB protection,
KPTCL shall explore the possibility of having split bus operation at
Ambewadi and submit the details of the same to PCSC forum.
2. KPTCL shall provide the details of the tripping of Supa hydro station
connected downstream from 110 kV bus.
Status received vide mail dated 10.07.2017:
1. Furnishing FIR & TR of the tripping events as per the formats provided
by SRLDC. --- Completed
2. ----- Pending
3. ----- Pending
4. Refered to OEM for the tripping of Tie CB of Munirabad line on SOTF
protection. ------ Pending
Review Meeting dated 19.12.2017:
2) & 3) KPCL inofmred that they had complied with the given
recommendations. --- Completed
4. KPCL informed that OEM is visiting RTPS December, 2017 end for
attending the SOTF problem. --- Pending
KPCLMultiple trippings at 400 kV RTPS
substation of KPCL
16- 03-2017 at
01:18 hrs
Bus-2 B-Ph differential bus bar protection operated
at 400 kV RTPS end, tripping all the main breakers
connected to Bus-2
GD-1 at 220kV Ambewadi Station of KPTCL Triggering incident was B-phase to earth fault in
220kV Ambewadi- Nagzari line-1. B-pole of breaker
did not open at Ambewadi end. LBB protection not
available at Ambewadi end. All elements tripped on
Zone-2 from remote ends.
22-12-2014 at
21:22 hrs
40/I/1 Mail received on 28-04-2015:
1. In view of operating 220kV Ambewadi SS in split bus mode, action is
being taken up by KPTCL. Problem in the 220kV bus coupler breaker is
attended and isolator overhauling work is under progress. Spilt bus
operation at Ambewadi will be made possible at the earliest. --- Pending
2. ICT Protection system at Ambewadi and trippings occured at Supa GS
during the instance is checked up and remedial measures already
furnished in this regard.
---- Completed
Mail recieved on 29-07-2015:
1. Action is being taken by KPTCL for operating Ambewadi in split bus
mode. Problem in bus coupler breaker is attended.Isolator overhaulling
work is completed.PTs are already provided to 220kV Bus-II. After
commissioning of Bus-II PTs, Ambewadi can be operated in split bus
mode. Pending works will be completed within a months time.
KPTCL mail recieved on 23-01-2016:
1. Bus-II PTs yet to be commissioned.Planned to complete before end of
April-2016.
KPTCL mail recieved on 25-04-2017 & 22.11.2017:
1. Yet to be attended --- Pending
63/II/10
Annexure-III
Page 19 of 37
220kV Sedam-
Tandur line
40/IV/1 PendingMail recieved on 29-07-2015:
Carrier protection is being restored for 220kV Sedam-Tandoor line at
Sedam end. After restoring the carrier protection , AR will be enabled.
KPTCL mail recieved on 23-01-2016:
Carrier protection is being restored for 220kV Sedam-Tandoor line at
Sedam end. After restoring the carrier protection , AR will be enabled.
KPTCL mail recieved on 25-05-2016:
SEE,SCADA to update the latest status
KPTCL mail recieved on 28-06-2016:
Action is being taken to restore carrier protection.AR will be enabled
once carrier signal is restored.
KPTCL Mail Recieved dated 22-11-2017:
The Wave traps required are supplied under R&U project and the same
is to be commisioned at Sedam end for restoration of PLCC. Also,M-II
distance relays have already been supplied by GE Ltd.
KPTCL Mail dated 16.12.2017:
Carrier protection is to be restored. B/U OC and EF relay is to be
replaced by M-II distance relay. Required materials like wave trap, M-II
distance relay are already supplied. The work will be taken up on top
priority through GE Ltd.
Review Meeting dated 19.12.2017:
KPTCL informed that the works relating to put A/R in service are going
on at their Sedam SS, and assured that it would be put into service by
February, 2018.
KPTCLKPTCL was requested to explore the possibility of providing A/R feature
to this line and submit the remedial measures to the PCSC forum.
Pending
KPTCL Mail dated 16.12.2017:
1 & 2) Replacement of Bus Bar Protection is included under R&U project.
Awarded to M/s GE Ltd. Panels have alredy been supplied by the
Agency. The work will be taken up on top priority.
Review Meeting dated 19.12.2017:
KPTCL informed that the works relating to put A/R in service are going
on at their Sedam SS, and assured that it would be put into service by
February, 2018.
Complete outage at 220kV Sedam
Substation of KPTCL (GD-1)
KPTCL 1. KPTCL to provide Bus bar and LBB protections for 220 kV bus at
Sedam S/s.
2. KPTCL to implement A/R feature on 220 kV Sedam-Tandur inter-
state line.
R-Phase to ground fault occurred on 220kV Sedam-
Shahpur line. Fault not cleared from Sedam end due
to stuck-breaker condition. While the Sedam-
Sahapur line tripped from Shahapur end in Zone-1,
the other 220 kv lines from Sedam tripped at remote
ends in Zone-2. This caused complete outage of
220kV Sedam substation.
27-01-2015 at
8.00 hrs
41/I/4
Line tripped on Yphase to earth fault from both the
ends
20-12-2014
at 22:20 hrs
Mail received on 28-04-2015:
Procurement of Bus bar and LBB protection is in the final tendering
stage. 2. Action is being taken to restore the carrier protection for 220kV
Sedam-Tandoor line. AR will be enabled.
Mail received on 29-07-2015:
1. Procurement of Bus bar and LBB protection is in the final tendering
stage.
2. Action is being taken to restore the carrier protection for 220kV
Sedam-Tandoor line. AR will be enabled after restoration of PLCC.
KPTCL mail received on 23-01-2016:
1. Bus bar protection panels pocured and erected at Sedam. Wiring ,
testing ,commissioning is being taken up.Planned to complete by April
2016.
2. Action is being taken to restore the carrier protection for 220kV
Sedam-Tandoor line. AR will be enabled after restoration of PLCC.
KPTCL Mail recieved dated 22-11-2017:
1 & 2). Bus Bar Protection panel and required Wave traps are supplied
under R&U. Wave trap to be commisioned in Tandoor line and PLCC to
be restored.Once PLCC is restored AR will be enabled. The Wave traps
required are supplied under R&U project and the same is to be
commisioned at Sedam end for restoration of PLCC.
Annexure-III
Page 20 of 37
Mail received on 29-07-2015:
1. Procurement of Bus bar and LBB protection is in the final tendering
stage.
2. Action is being taken to restore the carrier protection for 220kV
Sedam-Tandoor line. AR will be enabled after restoration of PLCC.
KPTCL Mail Recieved dated 22-11-2017 & 16.12.2017:
1.Enabling the AR feature was discussed during PCSC meetings and since
Ambewadi-Ponda and Ambewadi-Xeldom lines are radial lines, it was
decided that enabling AR is not required. To clear the faults in the
abovelines early, the timings of the Zone 2 was reduced to 150mS and
the Back Up EFR timings have been reducedto 150mS. --- Completed
2.The planned works as per R&M could not be taken up due to the
problem with the vendor and could not be taken up under R&U project
due to administrative reasons. ---- Pending
Review Meeting dated 19.12.2017:
2. The issue was discussed. Considering the importance of the
substation and delay in executing the works, it was decided to escalate
all pending issues relating to Ambewadi SS to KPTCL top Management
for early completion.
KPTCL
Mail received on 27-05-2015:
1. Bus Bar protection will be provded under R&U.
2. A/R yet to be enabled.
Mail received on 29-07-2015:
1. Procurement of Bus bar and LBB protection is in the final tendering
stage.
2. Action is being taken to restore the carrier protection for 220kV
Sedam-Tandoor line. AR will be enabled after restoration of PLCC.
KPTCL Mail Recieved dated 22-11-2017:
Bus Bar Protection panel and required Wave traps are supplied under
R&U. Wave trap to be commisioned in Tandoor line and PLCC to be
restored.Once PLCC is restored AR will be enabled.
KPTCL Mail dated 16.12.2017:
1. Replacement of Bus Bar Protection is included under R&U project.
Awarded to M/s GE Ltd. Panels have alredy been supplied by the
Agency. The work will be taken up on top priority.
2. AR feature will be enabled during retrofitting of Main-2 relays.
Pending
1. KPTCL shall provide A/R feature on Ambewadi – Ponda 220 kV D/C
inter-state line.
2. Till the completion of R&M works for bus bar and LBB protection,
KPTCL shall explore the possibility of having split bus operation at
Ambewadi and submit the details of the same to PCSC forum.
PendingFault in 220kV Ambewadi-Nagjheri line-212-03-2015 at
7:51 hrs
Complete outage of 220kV Sedam
substation of KPTCL
42/I/1 KPTCL
42/I/2 (GD)
Complete outage of 220kV Peenya
Substation in Karnataka
48/I/2
Complete outage of 220 kV Ambewadi
substation of KPTCL
PendingAll connected 220kV lines and transformers were
taken on 220kV North bus as South bus was under
shut down for conversion of strung bus to rigid bus
and isolator replacement under R&M works. Failure
of HV side Y phase CT of 150MVA Transformer-3
occurred at Peenya Substation which resulted in
operation of Differential and HV REF protection. The
failure of CT also resulted in a 220kV bus fault in
North Bus.
27-09-2015
at 4:23:17 hrs
KPTCL KPTCL to revise distance relay settings at Nelamangala end for 220 kV
Nelamangala – Hebbal - Peenya line – 1 for the effective line length of 17
km. These new settings can be appropriately reviewed as and when the
tie-arrangement at Hebbal is done away with.
KPTCL mail received on 25-05-2016:
Presentl 220kV Nelamangala -Hoody (i.e. nelamangala-Peenya-Hebbal -
Hoody line is made LIILO at Yelahanka sub station and breaker at
Peenya is kept open, necessary modification in distance relay settings
adopted for new configuration.
KPTCL Mail Recieved dated 22-11-2017:
Since usage of this line as an Incoming line at Peenya is required for
emrgency purposes, the settings of this line at Nelamangala end will be
reduced to 17KMs and as a special case, to cover the rest of the length
of the line, Zone 2 timing will be reduced to 150 ms.
KPTCL Mail dated 16.12.2017:
The revised settings to be adpopted for this line considering reduced
protected line length( 17KMs) is issued as a special case which will be
implemened and tested during scheduled outage.
Review Meeting dated 19.12.2017:
KPTCL informed that the revised setting would be implemented by
December, 2017.
1. KPTCL to provide Bus Bar protection and LBB protection at Sedam S/s
and furnish the status of their implementation to PCSC forum.
2. KPTCL to implement A/R feature on 220 kV Sedam-Tandur inter-state
line.
Fault occurred in 220kV Sedam-Shahpur line15-02-2015
at 14:24 hrs
Annexure-III
Page 21 of 37
48/I/3
51/II/21 KPTCL Mail received dated 25-05-2016:
SEE, RTC, Bangalore to update the status
KPTCL Mail received dated 28-06-2016:
Providing numerical bus bar protection to 400kV buses and GPS time
synchronising equipment at Guttur is considered under R&U. Work is
awarded to M/s Alstom, execution will be taken up shortly.
KPTCL Mail received dated 25-04-2017:
GPS and accessories will be supplied during May 2017, expected to
complete the work within a month after supply of materials.
KPTCL Mail Recieved dated 22-11-2017:
As discussed during the earlier PCSC meetings, current limit of 12.5KA
has been added in the logic of AR at Guttur end to prevent reclosing
during failure of LA or any other very close faults. Replacement of
existing static BBP by new numerical BBP with Main 1&2 will be taken up
at Guttur for which the panels are already supplied. Presently,
replacement of 220KV side Bus bar protection is under progress. DI for
delivery of GPS receiver has already been issued, but there is a delay in
dispatch of the same by M/s GE Ltd due to GST issues, which is also
addressed recently.
KPTCL to fast-track providing A/R on all 220 kV lines emanating from
Ambewadi SS to prevent Station shut-down on temporary faults.
220kV Ambewadi-Nagjheri line-2 tripped on B-phase
to earth fault. This resulted in loss of supply to
220kV Ambewadi bus. 220kV Ambewadi-Ponda line-
1&2 were hand tripped after deenergization of bus
at Ambewadi.
30-09-2015 at
10:41 hrs
Multiple tripping at 400kV Guttur SS 1. KPTCL to configure all DR’s and EL’s at 400 kV Guttur SS so that they
will also get triggered for BBP operation.
2. KPTCL to ensure time-synchronization of all DR’s and EL’s with GPS at
their 400 kV Guttur SS.
Failure of Lightning Arrestor of Y-phase Line Reactor
of 400kV Guttur-Hiriyur line-1 and line tripped on
distance protection Zone-1. Bus-bar protection of
400kV Bus-2 at Guttur substation also got operated
during the event sensing this through fault. 400/220
kV ICT-1 & 2 at Guttur, 400kV Kaiga-Guttur-2, 400kV
Guttur-Narendra-2, 400kV Guttur-Hiriyur-2 and
400kV Guttur-Munirabad which are on 400kV Bus-2
got tripped during the incident. 400kV Guttur-
Narendra-1 which was on Bus-1 also tripped at the
same time.
17-01-2016 at
18:53 hrs
PendingKPTCL mail received on 23-01-2016:
Will be complied in a months time.
KPTCL Mail Recieved dated 22-11-2017:
Enabling the AR feature was discussed during PCSC meetings and since
Ambewadi-Ponda and Ambewadi-Xeldom lines are radial lines, it was
decided that enabling AR is not required. To clear the faults in the
abovelines early, the timings of the Zone 2 was reduced to 150mS and
the Back Up EFR timings have been reducedto 150mS.
KPTCL Mail dated 16.12.2017:
Enabling the AR feature was discussed during PCSC meetings and since
Ambewadi-Ponda and Ambewadi-Xeldom lines are radial lines, it was
decided that enabling AR is not required. To clear the faults in the
abovelines early, the timings of the Zone 2 was reduced to 150mS and
the Back Up EFR timings have been reduced to 150mS. In view of the
above, it is requested to drop the issue from this list.
Review Meeting dated 19.12.2017:
KPTCL informed that AR would be enabled at Ambewadi end for lines
other than Ponda and Xeldom lines during retrofitting of Back Up
protection by Distance protection relay at Ambewadi.
Considering the importance of the substation and delay in executing
various works, it was decided to escalate all pending issues relating to
Ambewadi SS to KPTCL top Management for early completion.
KPTCL
PendingKPTCL
KPTCL Mail dated 16.12.2017:
1). The work of replacing static type 400kV Bus Bar Protection scheme
by numerical BBP is under progress at Guttur.
--- Pending
2). GPS time syncronising device is expected to be supplied before end
of December 2017 --- Pending
Review Meeting dated 19.12.2017:
1) & 2) KPTCL informed that the works are under progress, and are
targeted to br completed by February, 2018.
Outage of 220kV Ambewadi station in
Karnataka
Annexure-III
Page 22 of 37
KPTCL Mail received dated 25-05-2016:
SEE, RTC, Bangalore to update the status
KPTCL Mail Recieved dated 22-11-2017:
Since usage of this line as an Incoming line at Peenya is required for
emrgency purposes, the settings of this line at Nelamangala end will be
reduced to 17KMs and as a special case, to cover the rest of the length
of the line, Zone 2 timing will be reduced to 150 ms.
KPTCL Mail dated 16.12.2017:
Considering it as special case, revised settings to be adpopted for this
line considering reduced protected line length( 17KMs) is issued which
will be implemened and tested during next scheduled outage.
Review Meeting dated 19.12.2017:
KPTCL informed that the revised settings would be implemented by
December, 2017.
Pending
57/II/1
52/I/3 22-02-2016 at
15:03 hrs
Complete outage of 220 kV Shimoga
substation
53/I/1 Complete outage of 220kV Peenya
Substation of KPTCL
KPTCLKPTCL to operate 220 kV Shimoga on multi-bus operation under normal
conditions, and put it on single-bus operation only under emergency
conditions.
KPTCL Mail received dated 25-04-2017:
Replacement of existing BBP by new BBP with 4 zone protection is being
taken up under R&U.
KPTCL Mail Recieved dated 22-11-2017:
GE Ltd has already supplied the necessary Bus Bar protection panels for
replacement of the existing static type BBP by new numerical BBP with 4
zone protection under R&U project. The work of commissioning the
same will be taken up shortly.
KPTCL Mail dated 16.12.2017:
Due to operational constraints two/ multi bus operation is not being
implemented.
Review Meeting dated 19.12.2017:
It was noted that Shimoga SS is having required configuration for
providing double-bus operation. However, due to large no. of feeders
(15 in no) with variable gneration at certain remote ends like Varahi, the
flows on these lines are bound to vary. As such it is necessary to zero in
on appropriate arrangement of feeders on different buses so that bus-
isolators of the feeders are not overloaded.
The issue was discussed. KPTCL was asked to try out multi-bus operation
on trial basis to arrive at suitable arrangement of feeders.
KPTCL Mail Recieved dated 22-11-2017:
1. The necessary Bus Bar protection panels are already supplied to
Chikkodi under R&U project. Presently R&U works at sub stations
subjected to audit are taken up. After completion of PAR works, the
baove works are planned.
--- Pending
2. --- Pending
3. --- Pending
KPTCL mail dated 16.12.2017:
1.The necessary Bus Bar protection panels are already supplied to
Chikkodi under R&U project. Control cables have to be supplied.
Presently R&U works at sub stations subjected to audit are taken up.
After completion of PAR works at 26 Sub stations, remaining works will
be taken up through M/s GE.
--- Pending.
2. --- Pending
3. --- Pending
Review Meeting dated 19.12.2017:
1. KPTCL informed that BBP would be provided by April, 2018.
---- Pending
2. KPTCL informed that DPR settings had been reviewed.
---- Completed
3. EFR on failure of B-ph PT of 220 kV Bus-2 had been furnished to CEA. ---
- Completed
Pending
01-07-2016 at
03:03 hrs
KPTCL to furnish a report on the tripping of 220 kV Peenya-Nelamangala
line-4 Nelamangala detailing the remedial measures taken including the
settings adopted for Z1B (Zone extension) and Power Swing Block.
1.KPTCL to take steps to provide busbar protection at their 220 kV
Chikkodi inter-regional substation, and furnish a time-line for the same.
2.KPTCL to review distance protection settings for 220 kV Chikkodi –
Kudachi line.
3.KPTCL to furnish equipment failure report of the current incident to
PSE&TD Division of CEA with a copy marked to SRPC.
220kV Peenya-Nelamangala-3 tripped on B-E fault at
both ends. At the same time, 220kV Peenya-
Nelamangala-4 tripped on R-Y fault only at
Nelamangala end, and was in service from Peenya
end. Due to tripping of these two lines, 220kV
Peenya-Nelamangala-2 tripped on overcurrent
protection.
16-03-2016 at
11:39 Hrs
Tripping of 220 kV Chikkodi-Mudshingi and
220 kV Chikkodi-Talandage lines
Pending
220kV Bus Bar protection operated during failure of
R phase CT in DVG-2 line bay.
KPTCL
KPTCL
Triggering incident was failure of B-ph PT of 220kV
Bus-2 (western bus) at 220KV Chikkodi substation.
220KV Chikodi- Belgaum-I line tripped on DEFR
(Inst), 220KV Chikkodi-Kudachi line tripped on
Distance protection and also 100MVA transformer-2
tripped on E/F protection.
Annexure-III
Page 23 of 37
69/III/5 Tripping of 220 kV Sedam-Tandur line 10-10-2017 at
00:50 hrs &
10-10-2017 at
17:27 hrs
Tripped on Y-Phase to ground fault due to distance
protection operation. Auto reclosure could not be
validated from the submitted DR/EL.
KPTCL to enable and put A/R into service from Sedam end on 220 kV
Sedam – Tandur S/C line.
KPTCL Review Meeting dated 19.12.2017:
KPTCL informed that the works relating to put A/R in service are going
on at their Sedam SS, and assured that it would be put into service by
February, 2018.
Pending
KPTCL mail received dated 25.04.2017:
Numerical BBP is being provided under R&M works
KPTCL Mail Recieved dated 22-11-2017:
Tesing & Commissioning of numerical BBP at Somanahalli is under
progress. There was some technical issue wth BBP scheme supplied to
Somanahally which is being finalised in consultation with OEM SIFANG.
Numerical BBP will be commissioned at Somanahally within a month's
time.
KPTCL Mail dated 16.12.2017:
Numerical Bus Bar protection Scheme will be commissioned at
Somanahally before end of December 2017
20-01-2017 at
14:34 hrs
KPTCL to provide numerical Busbar Protection at their 220 kV
Somanahalli SS at the earliest.
KPTCL62/II/5 Tripping of 220 kV South Bus and
connected elements (220kV HSR, 220kV
Nagnathpura, 220 kV Harohalli, 220 kV
Subramanyapura, 220 kV Tataguni, 220 kV
Mallur and 400/220kV ICT-2 and 3) at
400/220kV Somanhalli substation of KPTCL
(Load loss: 850 MW)
Tripping of 220 kV Bus 2 and connected
elements (220kV HAL #1 and 2, 400/220 kV
ICT- 1, 2 and 220/66 kV ICT-2) at 400/220
kV Hoody substation of KPTCL (Load loss :
590 MW)
62/II/3 09-01-2017
at 23:06 hrs
Triggering incident was fault in 66 kV Somanahalli -
Bannerghatta line and fault was cleared by
operation of Back-up OCR at Somanahalli end.
Pending
1. KPTCL to provide Busbar protection at their 220 kV Hoody SS at the
earliest.
2. KPTCL to furnish an Equipment Failure Report on CT failure to CEA
with a copy marked to SRPC.
Failure of R-phase CT of 220/ 66 kV transformer-2 at
220kV Hoody end resulted in a bus fault in 220kV
Bus-2. Fault was cleared by backup protection of
ICT's (220kV lines were being radially operated) due
to absence of busbar protection
PendingKPTCL mail received dated 25.04.2017:
Numerical BBP is being provided under R&M works.
KPTCL Mail Recieved dated 22-11-2017:
1. Numerical Bus Bar protection panels have already been supplied as a
part of R&M works awarded to GE Ltd. Due to issue regarding the
sectionaliser CTs, the work had stopped. Now the same is resolved and
the the above work will be taken up after supply of sectionaliser CTs. ---
Pending
2. --- Pending
KPTCL Mail dated 16.12.2017:
1. Numerical Bus Bar protection panels have already been supplied as a
part of R&M works awarded to GE Ltd. Due to issue regarding the
sectionaliser CTs, the work had stopped. Now the same is resolved and
the the above work will be taken up after supply of sectionaliser CTs. ---
Pending
2. --- Pending
Review Meeting dated 19.12.2017:
1. KPTCL informed that BBP at 220 kV Hoody would be provided by
March, 2018.
---- Pending
2. EFR on failure of R-ph CT of 220/ 66 kV Transformer-2 had been
furnished to CEA. ---- Completed
KPTCL
Annexure-III
Page 24 of 37
KPCL/ KPTCL
KPCL/ KPTCL
Pending
Status informed during Special Meeting held on 03.06.2016:
1. KPTCL informed that the matter had been taken up with concerned
Line Operation and Maintenance wing to carry out corridor clearance
and maintenance as per schedule to avoid frequent line faults in this
corridor. A letter had also been addressed to Chief Engineer, Bhagalkot
zone, to ensure lines in & around Kali complex are maintained in healthy
condition. --- Completed
2. KPTCL assurd that the final modified SPS would be implemented at
Nagjheri PH at the earliest. ------ Pending
3. KPCL informed that Nagjhari- Kodasalli Lines 1 & 2 had been kept in
service since 23.05.2016 @ 08.06hrs.
--- Completed
KPTCL Mail received dated 28-06-2016:
2. Modifications to be carried in Nagzari SPS logic is submitted to
SRLDC/SRPC for verification and approval
Status received vide KPCL mail dated 14.06.2017:
1. Will be reviewed in consultation with EE(RT), KPTCL, Hubli.
3. Both the lines are in charged condition.
KPTCL Mail Recieved dated 22-11-2017:
1) & 3) --- Completed
2). Proposed revision in existing SPS scheme is already submitted to
SRLDC/SRPC., Yet to be discussed and approved by the SRPC forum. ---
Pending
Pending
KPTCL Mail dated 16.12.2017:
1) & 3). --- Completed.
2). Proposed revision in existing SPS scheme is already submitted to
SRLDC/SRPC., yet to be discussed and approved by the SRPC forum ---
Pending
Review Meeting dated 19.12.2017:
2. The SPS proposed by KPTCL was discussed and the PCSC forum
suggested certain changes for suitable incorporation. KPTCL agreed to
look into the same and assured that the modified SPS would be
furnished by January, 2018.
KPTCL Mail Recieved dated 22-11-2017:
1. coordination of KPCL has been requested for enabling AR lines
terminated to Nagajari.
2. AR will be enabled at Ambewadi end for lines other than Ponda and
Xeldom lines during retrofitting of Back Up protection by Distance
protection relay at Ambewadi.
KPTCL Mail dadted 16.12.2017 & Review Meeting dated 19.12.2017:
1. KPTCL informed that Coordination of KPCL has been requested for
enabling AR lines terminated to Nagajari.
--- Pending
2. KPTCL informed that AR would be enabled at Ambewadi end for lines
other than Ponda and Xeldom lines during retrofitting of Back Up
protection by Distance protection relay at Ambewadi. -- Pending
29.10.2015 at
14:34 hrs
49/I/3
Complete outage of 220 kV Nagjheri power
station and 220 kV Ambewadi substation
of KPTCL
51/I/3
Complete outage of 220kV Ambewadi
Substation of KPTCL
1. To avoid tripping of transmission lines on transient faults, KPCL/
KPTCL is recommended to carry out periodic patrolling of lines, and
ensure their proper maintenance by carrying out jungle/ bushing
clearance and trimming of tree branches within the RoW of transmission
lines as per the SRPC transmission line patrolling guidelines (available
under the menu item "All Uploads/ Operation/ Miscellaneous/
Transmission Line Patrolling Protocol / Guidelines for Southern Region"
on SRPC website).
2. KPCL/ KPTCL to review operation of SPS at NPH for functionality
(reduction of generation with tripping of evacuating lines) and
healthiness.
3. KPCL to put 220 kV Kodasalli - Nagjheri D/C lines into service if more
than 200 MW generation from Kali Complex (with Nagheri Contribution
not less than 50 MW) is ensured on sustained basis.
220kV lines from Nagjheri power house started
tripping from 11:00 hrs due to fault in lines. The
sequence of tripping is shown in SOE list. At 12:33
hrs, 220kV Narendra-Ambewadi lines-1&2 got
tripped which resulted in loss of evacuation path to
Nagjheri station resulting in tripping of running Units
and complete outage at Nagjhheri power station.
220kV Ambewadi station also got de-energized due
to tripping of source feeders i.e. 220kV Narendra-
Ambewadi-1&2 and 220kV Nagjheri-Ambewadi-1&2.
220kV Nagjheri-Ambewadi line-1 tripped at 13:33
hrs due to B phase to earth fault. Ambewadi was
radially fed from Nagjheri power station through
220kV Nagjheri-Ambewadi line-2. Tripping of this
line caused 220kV Bus shut down at Ambewadi and
remaining lines and transformers were hand tripped
1. KPCL to provide A/R on all 220 kV lines emanating from Nagjheri PH.
2. KPTCL to provide A/R on all 220 kV lines emanating from Ambewadi
SS.
22-02-2016 at
12:36 hrs
Annexure-III
Page 25 of 37
TANGEDCOFailure of Bus Section-I Y-ph CT resulted in operation
of bus-bar protection for Bus Sections -I & II.
Running Units#1, 4 and 5, 230 kV Kayathar, 230kV
Kudankulam, 230kV Sterlite, Station Transformer-1,
2 & 3 got tripped during the incident. Unit – 2 & 3
were not in service.
KPTCL Mail received dated 28-06-2016:
Modifications to be carried in Nagzari SPS logic is submitted to
SRLDC/SRPC for verification and approval
Status received vide KPCL mail dated 14.06.2017:
1. Tripped since there was evacuation problem and there were only two
lines NA-1 and NA-2 ---- Completed
2. Will be reviewed in consultation with EE(RT), KPTCL, Hubli. --- Pending
3. Both the lines are in charged condition. --- Completed.
KPTCL Mail Recieved dated 22-11-2017:
2. Proposed revision in existing SPS scheme is already submitted to
SRLDC/SRPC., yet to be discussed and approved by the SRPC forum. ---
Pending
KPTCL Mail dated 16.12.2017:
1) & 3). --- Completed.
2). Proposed revision in existing SPS scheme is already submitted to
SRLDC/SRPC., yet to be discussed and approved by the SRPC forum ---
Pending
Review Meeting dated 19.12.2017:
2. The SPS proposed by KPTCL was discussed and the PCSC forum
suggested certain changes for suitable incorporation. KPTCL agreed to
look into the same and assured that the modified SPS would be
furnished by January, 2018.
18-03-2016 at
14:40 hrs
Complete outage of 220kV Ambewadi
station of KPTCL and 220kV Nagjheri of
KPCL
53/I/3
TANGEDCO mail dated 15.04.2017:
1) New Relay is tested and ready for replacement.Now all 5 units are in
service.The relay will be replaced when lesser units are in service. ---
Pending
2.a)Steps are taken to renovate & mordernization of all the control panel
into Numerical based control panels. --- Pending
2.b) Since 230 KV indoor switchyard has no spare space providing dual
CT`s is not fessible. -- Completed
3) Procurement of EL & DR is under progress. --- Pending
TANGEDCO mail dated 26.04.2017:
1) Check zone New Relay is replaced on 17.04.2017 -- Completed.
2. --- Pending
3. --- Pending
TANGEDCO mail dated 13.12.2017:
2).P & C wing gives clearance to TTPS to procure the Bus bar protection
relays and protection relays and SER / DR system vide
Lr.CE/P&C/SE/D/EEPC4/AEE3/F.TECH/D.27/17 Dated: 05.10.2017. To get
administrative approval budgetary offer has bar protection relay from
various companies ----Pending
3). SRPC vide Lr: SRPC/SE- III/CEA/2017/6450/DT:27.10.2017 gives
features of SER/DR. Budgetary offer will be called for SER / DR having
above features. ---Penidng
Review Meeting dated 19.12.2017:
2) & 3) The issue was discussed and TANGEDCO was asked to provide
time-line for implementing the recommendations.
Ambewadi Narendra line-2 tripped on fault and
220kV ambewadi Narendra line-1 tripped due to
over-loading. Running Units at Nagjheri also tripped
during the event due to tripping of evacuating lines
1. KPCL to furnish a report on the reasons for Unit-6 tripping at Nagjheri
PH.
2. KPCL/ KPTCL to modify suitably the SPS at Nagjheri Power House such
that it would also factor in the over loading of Ambewadi-Narendra lines.
3. KPCL to put 220 kV Kodasalli - Nagjheri D/C lines into service if more
than 200 MW generation from Kali Complex (with Nagheri Contribution
not less than 50 MW) is ensured on sustained basis.
PendingTripping of running Units & 230kV feeders
at Tuticorin TPS of TANGEDCO
(Gen Loss: 640 MW)
62/II/7 1. TANGEDCO to replace existing Check-Zone relay with a new one
possessing required performance.
2. TANGEDCO to take steps to provide numerical busbar protection at
their 220 kV Tuticorin TPS. TANGEDCO may also explore providing dual
CT’s (on either side) for all B/S breaakers at the time of commissioning of
numerical BBP, if there were no space constraints.
3. TANGEDCO to take steps to provide for standalone Event Logger (EL)
and standalone Disturbance Recorder (DR) with automatic downloading
facility to a centralized server.
KPCL/ KPTCL Pending
Tamil Nadu
25-01-2017 at
22:36 hrs
Annexure-III
Page 26 of 37
TANTRANSCO vide their mail dated 24.06.15 informed that different
relays in Main-I & Main-II would be ensured at the earliest.
Mail recieved on 24-07-2015 ,19-02-2016 and 24-03-2016:
Different relays in Main-I & Main-II will be ensured.
Mail received on 27-04-2016:
TANTRANSCO: Not feasible in the existing SAS sub stations. Hence,
exemption may be given for these sub stations.
Mail received on 20-05-2016 ,16-06-2016,25-07-2016 & 24-09-2016 :
As discussed in the 52nd PCSC meeting, Swapping of Relays between two
stations is not feasible in the existing SAS sub stations. Hence, exemption
may be given for these sub stations.
Status received vide mails received on 10-11-2016 & 20.12.2016 &
12.04.2017 & 01.06.2017 & 15.06.2017 & 04.08.2017:
Different make Relays will be ensured for Main-I & II relays at Alamathy
end.
TANTRANSCO Mail received on 118-09-2017 & 31-10-2017
Different make Relays will be ensured for Main-I & II relays at Alamathy
end.
TANTRANSCO mail dated 12.04.2017:
1. The recommendation will be ensured. AR logic will be configured in
Distance Protection relay itself instead of BCU. OEM has been addressed.
2. Post triggering period of 2 sec. to cover AR operation in DR time scale
will be provided.
TANTRANSCO mail dated 01.06.2017 & 15.06.2017:
1. The recommendation will be ensured. AR logic will be configured in
Distance Protection relay itself instead of BCU. OEM has been addressed.
Main-1 & 2 relays will be replaced for the requirement of more output
contacts for AR logic implementation.
2. Post triggering period of 2 sec. to cover AR operation in DR time scale
is being provided.
TANTRANSCO mail dated 04.08.2017:
1. The recommendation will be ensured. AR logic will be configured in
Distance Protection relay itself instead of BCU. OEM has been addressed.
Main-1 & 2 relays will be replaced for the requirement of more output
contacts for AR logic implementation.
2. Post triggering period of 2 sec. to cover AR operation in DR time scale
is provided. ----- Completed
TANTRANSCO mail dated 18-09-2017 & 31-10-2017.
1. The recommendation will be ensured. AR logic will be configured in
Distance Protection relay itself instead of BCU. OEM has been addressed.
Main-1 & 2 relays will be replaced for the requirement of more output
contacts for AR logic implementation.
2. Post triggering period of 2 sec. to cover AR operation in DR time scale
is provided at NCTPS-II . -----Completed
Status received vide mail dated 12-12-2017:
1. The recommendation will be ensured. AR logic will be configured in
Distance protection relay itself instead of BCU. OEM has been addressed.
Main 1 &2 relays will be replaced for the requirement of more output
contacts for AR logic implementation ----Pending
2. Completed
22-02-2017 at
06:16 hrs
Pending
TANGEDCO Mail dated 13-12-2017 & Review Meeting dated
19.12.2017:
1).As a Part of Project Pending M/s. BHEL/TBG has agreed to take up this
issue with M/s.GE T&D Ltd,. and the work will be completed by
31.03.2018. --- Pending
2) --- Completed
TANGEDCO1. TANGEDCO to take properly configure A/R logic at NCTPS-II in that in
case of unsuccessful auto-reclsoure, three-phase trip shall be given along
with A/R block.
2. TANGEDCO to configure all protection relays DR’s time scale at NCTPS-
II for a post-triggering period of 2 sec to capture events such as
complete A/R operation.
R-phase to earth fault due to de-capping of
insulator. Auto-reclose attempt was unsuccessful.
Line-2 tripped on R-phase to earth fault.
Line autoreclosed at SVChatram end and failed to
reclose at Alamathy end. Bphase to earth fault in
line-1. Line tried for A/r but due to permanent fault
line did not reclose. ICT tripped on operation of over
flux protection.
43/II/5
62/V/3
PendingTripping of 400kV
Alamathy-
SVChatram line-1&2
and 400/230kV ICT
at S.V.Chatram
TANTRANSCOTANTRANSCO was requested to swap the relays between two stations,
so that Main-1 and Main-2 will be of different make at each station.
Tripping of 400 kV NCTPS-S.V.Chatram line-
2
29-03-2015 at
15:29 hrs
Annexure-III
Page 27 of 37
Review Meeting dated 19.12.2017:
TANTRANSCO informed that 230 kV OK Mandapam - Myvady feeer was
LILOed at Anaikadavu on 06.11.2017. Further replacement of the
existing Kundah condductor with Zebra has also been taken up, and is
targeted to be completed by June, 2018.
TANTRANSCO
PendingTANTRANSCO Mail received on 19-02-2016, 24-03-2016 and 27-04-
2016:
230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal
Nagar. Line restringing will be carried out along with the above proposal.
Mail Received on 20-05-2016 ,16-06-2016,25-07-2016 & 24-09-2016:
230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal
Nagar. Line restringing will be carried out along with the above proposal.
Status received vide mails received on 10-11-2016 & 20.12.2016 &
12.04.2017 & 01.06.2017 & 15-06-2017 & 04.08.2017:
230kV Othakalmandapam - Myvadi feeder will be made LILO at Kongal
Nagar. Line restringing will be carried out along with the above proposal.
TANTRANSCO mail dated 18-09-2017 & 31-10-2017:
Othakalmandapam - Myvadi feeder will be made LILO at Kongal Nagar.
Line restringing will be carried out along with the above proposal.
Status received vid email dated 12-12-2017:
Othakalmandapam - Myvadi feeder replacement of kundha conductor
with Zebra and tower replacement work has been sanctioned. Work will
be taken up.
TANTRANSCO Mail received on 19-02-2016 and 24-03-2016:
Revision of Bus Bar Protection setting was carried out. The stabilizing
voltage setting was raised from 410 to 450 volts. After completing the
necessary test, the bus bar protection put in to service on 29.12.2015.
Mail Received on 27-04-2016 ,16-06-2016,25-07-2016 & 24-09-2016:
Revision of Bus Bar Protection setting was carried out. After completing
the necessary test, the bus bar protection put in to service on
29.12.2015.
Mail received on 10-11-2016 & 20.12.2016:
Provision of Bus Coupler bay arrangement was included in the
Upgradation works proposed and the same was sanctioned by MoP
through PSDF.
Numerical relay allotted and being commissioned.
Mail received on 20-02-2017:
Numerical BBP relay was commissioned on 02.02.2017
Status received vide mail dated 12.04.2017 & 01.06.2017 & 15-06-2017:
Numerical BBP relay was commissioned on 02.02.2017.
Provision of Bus Coupler bay arrangement was included in the
Upgradation works proposed and the same was sanctioned by MoP
through PSDF.
Status received vide mail dated 04.08.2017:
Numerical BBP relay was commissioned on 02.02.2017.
Provision of CT in Bus Coupler bay is arranged and zone segregation will
be provided.
Pending50/I/3 21-12-2015 at
6:28 hrs
Disturbance in 220kV Tamilnadu system TANTRANSCO TANTRANSCO to take suitable measures like installing more stub-
towers along 230 kV OK Mandapam – Myvady line to avoid excessive sag
due to over-loading.
Complete outage of 230kV Palladam, 230 kV
Othakalmandapam S/s, 230 kV Coimbatore S/s, 230
kV Thudialur and 230 kV Sadayapalayam S/s
05-09-2015 at
14:04 hrs
TANTRANSCO to examine the feasibility of providing two main-zone
operation for bus bar protection by exploring various alternatives like
replacing existing bus-coupler CB with a hybrid bus-coupler CB that
comes with inbuilt CT, replacing existing BBP relay with another suitable
relay that supports two main-zone operation, and implement the same.
Busbar protection got operated for a fault in 230kV
Mywadi-Anaikadavu line
Complete outage of 230kV Mywadi station
of TANTRANSCO
TANTRANSCO Mail dated 12-12-2017:
Different make Relays will be ensured for Main-I & II relays at Alamathy
end. Tender floated for relay procurement.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that the recommendation would be complied
with by June, 2018.
48/I/1
Annexure-III
Page 28 of 37
TANTRANSCO mail received on 24-03-2016:
CMR relay for extending LBB protection was released and LBB extended
from Distance Protection relay directly. CT is not available in the Bus
Coupler bay for zone segregation. However, during commissioning of
third ICT, Bus section Breaker will be provided for zone segregation.
Numerical BBP relay will be provided.
Status received vide mails recieved on 27-04-2016 and 20-05-2016 ,16-
06-2016, 25-07-2016, 24-09-2016,10-11-2016 & 20.12.2016 &
12.04.2017 & 01.06.2017 & 15-06-2017:
1 & 2) CT is not available in the Bus Coupler bay for zone segregation.
However, during commissioning of third ICT, Bus section Breaker will be
provided for zone segregation. Numerical BBP relay will be provided.
Status received vide mail dated 04.08.2017:
1 & 2) Contract awarded for providing third ICT & Bus modification
works to accomodate bus coupler bay. Numerical BBP relay has been
provided and tesing under progress.
Status received vide mail dated 18.09.2017:
1 & 2) Contract awarded for providing third ICT & Bus modification
works to accomodate bus coupler bay. Numerical BBP relay has been
provided and tesing under progress.
Status received vide mail dated 01.11.2017:
1 & 2) Contract awarded for providing third ICT & Bus modification
works to accomodate bus coupler bay.
Numerical BBP relay was commissioned onj 29.08.2017.
Pending
Status received vid email dated 12-12-2017:
1 & 2) Numerical BBP relay was commissioned on 29.08.2017. Contract
awarded for providing third ICT & Bus modification works to
accomodate bus coupler bay. --- Pending
3) --- Pending
Review Meeting dated 19.12.2017:
1&2) TANTRANSCO informed that multi-bus operation with Numerical
BBP would be provided by June, 2018 for which the works are under
progress. --- Pending
3) TANTRANSCO informed that they would revert on providing Re-Trip
feature fro LBB. --- Pending
Complete outage of 230kV Madurai S/s
(Chekanaurani) of TANTRANSCO
TANTRANSCO 1. TANTRANSCO to provide split-bus operation with bus sectionalizer CB
for their 230 kV Madurai (Chekanurani) SS.
2. TANTRANSCO to provide two main-zone operation for the numerical
BBP that is being commissioned.
3. TANTRANSCO to examine the feasibility of providing Re-Trip feature
for the LBB protection, and accordingly take steps for implementing the
same.
Fault had occurred in 230kV Madurai-Sembatty line.
Trip from distance relay was not extended to
breaker due to protection DC fail. LBB protection got
operated resulting in a busbar trip at 230kV Madurai
substation. All elements got tripped as there is a
single bus operation at 230kV Madurai S/s
19-01-2016
at 11:56 hrs
Status received vide mail dated 18-09-2017 & 31-20-2017:
Numerical BBP relay was commissioned on 02.02.2017. Provision of CT in
Bus Coupler bay is arranged and zone segregation will be provided.
Status received vid email dated 12-12-2017:
Numerical BBP relay was commissioned on 02.02.2017. Provision of CT in
Bus Coupler bay has been allotted. Zone segregation will be provided
after commissioning of CT.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that the recommendation would be complied
with by March, 2018.
51/I/1 (GD)
Annexure-III
Page 29 of 37
14-09-2016 at
11:13Hrs
Bus Bar Protection (Zone-2) of 230 kV Bus-B got
operated at Alamathy Station during fault in 230 kV
Alamathy-Korattur feeder.
Pending
TANTRANSCO to take steps to provide double-bus operation at their
230 kV Gummidipoondi SS.
TANTRANSCO Pending
Mail recieved on 25-07-2016 & 24-09-2016:
TANTRANSCO: Auto Transformer-2 HV side Bus isolator 'C'-phase support
insulator of 230kV Southern Bus was replaced and Bus Bar Protection
scheme was restored on 12.05.2016.
Status received vide mails received on 10-11-2016 & 20.12.2016 &
12.04.2017 & 01.06.2017 & 15-06-2017 & 04.08.2017 & 18.09.2017:
CT is not available in the Bus Coupler bay for zone segregation. CT latch
relay is to be provided for all bays for zone segregation.
Status received vide mails received on 31-10-2017 & 12-12-2017:
Numerical Bus bar protection panel allotted and will be commissioned
with zone segregation..
Review Meeting dated 19.12.2017:
TANTRANSCO informed that Numerical BBP would be commissioned by
March, 2018.
TANTRANSCO Pending
Mail received on 10-11-2016 & 20.12.2016:
1. The Bus Bar Protection scheme will be tested for healthiness including
the CT circuits.
2. High impedance BBP relay will be replaced by Numerical relay.
Status received vide mails dated 10.01.2017 & 12.04.2017 &
01.06.2017 & 15-06-2017:
1. The Bus Bar Protection scheme was tested for healthiness including
the CT circuits. AREVA make CTs in Alamathy SS are having different
kneepoint voltage for the cores. CT cores of higher knee point voltage
has been choosen for BBP in 230kV Korattur, 230kV OPG-1 & 230kV OPG-
2 feeders on 29.11.2016. ---- Completed.
2. High impedance BBP relay will be replaced by Numerical relay. ---
Pending,
Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-
2017 & 12-12-2017.
1. ---- Completed
2. High impedance BBP relay will be replaced by Numerical relay. ---
Pending
Review Meeting dated 19.12.2017:
2) TANTRANSCO informed that Numerical BBP would be provided by
April, 2018 --- Pending
15-09-2016 at
22:14 hrs
Multiple tripping at 230 kV Alamathy
Station
Complete outage of 230 kV
Gummidipoondi Station of TANTRANSCO
58
58/II/17
55/I/1 (GD)
Bus Bar Protection (Zone1) of 230kV Bus-A got
operated at Alamathy Station during fault in 230 kV
Alamathy-OPG-1 feeder.
Different type and Make of distance protection relays to be provided for Main-I & Main-II protection for 230kV feeders at 400 kV Sunguvarchathiram & 230 kV Sunguvarchathiram Substation
[Carry-Over from Protection Audit Recommendations]
1. TANTRANSCO to check the healthiness of BBP relay by conducting
stability test, and take appropriate remedial action like increasing
voltage settings, ensuring the healthiness of CT’s, using CT’s with similar
characteristics (equal saturation effects & equal winding resistances) etc.
at their 230 kV Alamathy SS.
2. TANTRANSCO to replace the existing high-impedance BBP relay with
its low-impedance/ numerical variant so as to accommodate variation in
CT characteristics at their 230 kV Alamathy SS.
The issue was discussed in PCSC-58 meeting held on 18.10.2016, when
PCSC forum agreed to de-link the implementation of the Item from the
scope of Protection Audit Recommendations (PAR), and pursue it as
part of PCSC Recommendations.
Status received vide mails dated 10.01.2017 & 12.04.2017 &
01.06.2017 &15-06-2017 & 04.08.2017 & 18.09.2017 & 31-10-2017& 12-
12-2017:
Different make Relays will be provided for Main-I & II relays at
Sunguvarchatram end in a phased manner.
Review Meeting dated 19.12.2017:
TANTRANSCO informed that the recommended works of providing
different make Relays for Main-I & Main-II are targeted to be completed
by September, 2018.
TANTRANSCO
Flashover of Auto Transformer- 2 HV
B-phase Isolator supporting insulator of 230kV
Southern Bus occurred at Gummidipoondi station.
At the time of fault, Bus bar protection relay was not
in service for pre-commissioning testing of Auto
Transformer-2. All feeders got tripped due to
operation of zone-2 protection from remote ends.
12-05-2016 at
12:15 hrs
Annexure-III
Page 30 of 37
68/I/1 Complete outage of 230kV Alundur
substation of Tamil Nadu
11-09-2017
at 01:07 hrs
Triggering incident was failure of 230/110kV, 100
MVA, Auto transformer HV 2 ‘Y’ phase CT. Both
Buses got tripped on operation of busbar protection
resulting in tripping of all connected 230 kV
elements
1. TANTRANSCO to furnish Equipment Failure Report on the blasting of
230 kV Y-ph CT of Auto-Transformer-2 to CEA with a copy marked to
SRPC.
TANTRANSCO Status received vide mail dated 12-12-2017 & Review Meeting dated
19.12.2017:
Report will be sent to CEA
Pending
TANTRANSCO
Status received vide mails dated 04.08.2017 & 18.09.2017 & 31-10-
2017:
1. All the Porcelain insulators were replaced with Polymer insulators in
230kV NCTPS-I - Tondiarpet feeders - 1 & 2.
---- Completed
2. AR will be implemented on all 230kV lines emanating from NCTPS-I. ---
Pending
Status received vid email dated 12-12-2017:
1. Completed
2. The scheme needs modification to enable AR, since AR was not
envisaged for this station during commissioning. AR will be implemented
on all 230kV lines emanating from NCTPS-I within six months. --- Pending
Review Meeting dated 19.12.2017:
2) TANTRANSCO informed that A/R would be implemented on all 230 kV
lines emanating from NCTPS-I by June, 2018.
PendingTANTRANSCOComplete outage of North Chennai TPS
STG-1
Status received vide mails dated 18.09.2017 & 31-10-2017:
1. D60 Relay DRs for sensing the Phase-Earth fault as Phase-Phase fault
at S.V.Chatram end will be sent to OEM for analysis and rectification.
2. Resistive reach settings for the Main-1&2 Relays at S.V.Chatram end
are found in order. ----Completed
Status received vide mail dated 12-12-2017 & Review Meeting dated
19.12.2017:
1. D60 Relay DRs sent to OEM for analysis and rectification and as
recommended flex logic changes will be made by December 2017. ----
Pending
2. Resistive reach settings for the Main-1&2 Relays at S.V.Chatram end
are found in order. ---- Completed.
Pending66/ III/ 2 R-phase to earth fault had occurred in line. Auto-
reclose was successful at Alamathy and breaker got
tripped at S.V.Chatram
Tripping of 400 kV Alamathy-SV.Chatram
line-1
06-06-2017 at
22:03 hrs
1. TANTRANSCO to take up firmware issue of D60 relays with their OEM,
and get them upgraded appropriately.
2. TANTRANSCO to check the resistive reach settings of SV Chatram end
relays for the line under consideration.
64/1/4 26-03-2017
at 23:14hrs
1. TANTRANSCO to take steps to complete insulator replacement works
on the 230 kV lines owned by them in NCTPS area within 6 months.
2. TANTRANSCO to take steps to implement A/R on all 230 kV lines
emanating from NCTPS-I at the earliest.
Tripping of evacuating lines due to fault led to
tripping of running Unit at NCTPS Stg-1
Annexure-III
Page 31 of 37
Kerala
44/I/1 220 kV breaker of unit-3 at Idukki Power
house flashed and bus differential protection
acted. All Generators (6Nos.) along with all
220 kV feeders tripped during the incident.
28-04-2015 at
12:30 Hrs
KSEB Mail dated 25-05-2016:
1.Generation wing is planning ti provide low impedance REF protection
by retrofitting numerical ABB make transformer management relay in
the existing panel.
--- Pending
KSEB Mail dated 12-12-2017:
1. On consultation with OEM, it was understood that the retrofitting of
numerical ABB make transformer management relay in the existing
panel is not possible. Generation wing is planning to change the panels
as part of RMU and is scheduled to start from January'18 beginning. ---
Pending
Pending KSEB1. KSEB to reduce sensitivity of REF protection appropriately at Idukki
PH.
2. KSEB to replace/ repair the faulty breaker.
3. KSEB to check the PLCC equipment at New Pallom and inform the
remedial measures taken to PCSC forum.
Complete outage of Idukki Hydro Power
Station (GD-1)
Mail received on 31-07-2015:
1. Reducing the sensitivity of REF protection of Unit # 4, 5, 6 at Idukki
PH: - Generation wing is planning to purchase new transformer
management relays with low impedance REF protection. Purchase
procedures initiated. ---------Pending
2. The replacement/ repair of faulty breakers are under the
consideration of Generation wing. Breakers will be replaced / repaired in
a phased manner. Unit #3 breaker was replaced with available breaker
from the 220kV IDMD feeder. The 220kV CBs of unit #2 and unit #3 will
be replaced with in two months.
--- Pending
3. No abnormalities were noticed in the PLCC equipment at New Pallom
station. It is kept under observation. --- Pending
Mail recieved on 30-10-2015:
1. Purchase procedures is still in progress --- Pending
2. Replaced. --- Completed.
3. PLCC equipment Tested and found OK --- Completed.
Mail recieved on 03-03-2016:
1. Even though repeated plans to have a joint inspection with M/s.ABB
who is the OEM of the relay panel for replacing the relays with numerical
ones, the same could not become successful. Finally, the inspection has
been fixed on 15.03.2016. It has been planned to replace existing REF
protection with low impedance ones after retrofitting the numerical
ones of OEM.
--- Pending
Annexure-III
Page 32 of 37
55/II/9 Tripping of HVDC Gazuwaka pole-2 19-05-2016 at
11:41 hrs
Pole tripped on operation of differential current
protection of east side of Pole-2
PGCIL (SR-I) to take up the issue of differential protection operation of
converter transformer on low voltage fluctuations with their OEM, and
submit a detailed report on it.
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017 :
Issue taken up with OEM and still under study. Till now the OEM could
not explain the reason for the said operation of protection. All data has
been shared with OEM and further perused to identify the cause of the
same and remedial action.
Pending
56/II/11 Tripping of HVDC GazuwakaPole-2 19-06-2016 at
5:20 Hrs
HVDC Pole-2 got tripped on operation of Bus
differential protection
PGCIL (SR-I) to get the tripping of HVDC Pole-2 tripping on Win-Bus
differential protection thoroughly investigated for correctness of
operation, and submit a report thereon.
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:
Issue taken up with OEM and still under study. Till now the OEM could
not explain the reason for the said operation of protection. All data has
been shared with OEM and further perused to identify the cause of the
same and remedial action.
Review Meeting dated 19.12.2017:
Pending
67/II/5 Tripping of HVDC Bhadravati Pole-1 07-07-2017 at
10:59 hrs
Pole-1 tripped due to PC1 INTERNAL MINOR ALARM
WEST - ALARM. Pole protection extended trip
without any protection operation
PGCIL (SR-I) in coordination with PGCIL (WR-I) to take up the issue with
its OEM, and furnish the reasons for Pole-1 tripping along with remedial
measures taken.
PGCIL (SR-I) Review Meeting dated 19.12.2017:
PGCIL (SR-I) was asked to take up the sissue with PGCIL (WR-I) and
furnish action taken report by 10.01.2018.
Pending
67/II/6 Tripping of HVDC Bhadravati Pole-1 09-07-2017 at
14:43 hrs
Pole-1 tripped due to PC1 INTERNAL MINOR ALARM
WEST - ALARM. Pole protection extended trip
without any protection operation
PGCIL (SR-I) in coordination with PGCIL (WR-I) to take up the issue with
its OEM, and furnish the reasons for Pole-1 tripping along with remedial
measures taken.
PGCIL (SR-I) Review Meeting dated 19.12.2017:
PGCIL (SR-I) was asked to take up the sissue with PGCIL (WR-I) and
furnish action taken report by 10.01.2018.
Pending
PendingPGCIL (SR-I) Mail dated 15.12.2017 & Review Meeting dated
19.12.2017:
Issue taken up with OEM and still under study. Till now the OEM could
not explain the reason for the said operation of protection for Pole 2 . All
data has been shared with OEM and further perused to identify the
cause of the same and remedial action thereof if any.
PGCIL (SR-I)PGCIL (SR-I) to furnish detailed report on the events that led to tripping
of HVDC Poles – 1 & 2 including remedial measures taken to PCSC forum.
Further, the OEM report w.r.t. tripping of HVDC Pole-2 shall also be
furnished.
HVDC pole-1 got tripped due to operation of South
filter inter zone protection and HVDC pole-2 got
tripped due to operation of differential protection
25-05-2017 at
09:45 hrs
Tripping of HVDC Gazuwaka Pole-1&2 65/II/15
23-08-2016
at 11:20 hrs
KSEBKSEB to take steps to provide the following at their 220/ 110 kV
Kalamassery SS:
1. Busbar protection at 110 kV level
2. Connecting 220 kV and 110 kV sides on to a common earthmat
3. Redundant DC supply for both protection (220 V) and communication
(48 V) applications
4. Stand-alone Event Logger
Pending
PGCIL (SR-I) & PGCIL (SR-II)
Complete outage of 220 kV Kalamassery
Substation
58/I/1 (GD) Triggering incident was conductor snapping in 110
kV Kalamassery- Kaloor feeder
Status received vide mail dated 12-12-2017:
1. Detailed engineering of the scheme has been completed. Material
procurement is in progress. ---Pending
2.,3. ---- Completed
4. The SOE and DR are available with time stamping from the numerical
relays. Hence stand alone event logger is not necessary ----- Completed
KSEB Mail received vide dated 17.01.2017:
1. 110 kV bus bar protection progressing ----Pending
2. Connection of 220kV earth mat and 110 kV plate earthing system
completed.---- Completed
3. Redundancy of 110V DC system in progress. Complete independent
redundancy is not practical for the time being. 48 V DC redundancy was
already there. ----Pending
4. Instead of stand alone event logger, SCADA system of 110 kV feeder is
expected to be completed by the end of 2017. SCADA system of 220kV
side will be taken up after that ----Pending
KSEB Mail received vide dated 18.09.2017:
1. 110 kV bus bar protection is under progress
--- Pending
2. --- Completed
3. Redundacny of DC supply for both 110kV and 48v. Provided separate
DC source (Redundant) for protection of 220kV feeders and
transformers. 48V DC redundacy is already there. --- Completed
4. Stand-alone 'event logger:- Numerical relays with time
synchronization is available at 220kV substation Kalamassery and DRand
El is downloaded from these relays. KSEBl is not following Stand-alone
event logger for substation. --- Completed
Annexure-III
Page 33 of 37
24.11.2017
at 13:06 hrs
24.11.2017
at 14:26 hrs
70/III/4 Tripping of 400 kV Ramagundam-
Chandrapur line-2
15-11-2017 at
13:17 hrs
R-phase to earth fault had occurred in line. line auto-
reclosed at Ramagundam end
PGCIL (SR-I) to furnish an action taken report on the reasons for A/R
non-operation at Chandrapur end including remedial measures taken to
PCSC forum.
PGCIL (SR-I) Yet to be Informed Pending
PendingLines tripped during a fault on 400 kV Nellore-PG –
Vijayawada line-2
1. For the 400 kV Nellore-PG – Vijayawada line, PGCIL (SR-I) to
investigate the reasons for 3-ph tripping of Main-CB upon detection of
the fault without trying for A/R and operation of Stub/ Tee protection at
the time of Tie-CB A/R attempt at Vijayawada end during instant
trippings, and furnish remedial measures taken to address the issues
involved.
2. PGCIL (SR-I) to test the recently commissioned CSD’s at their 400 kV
Nellore-PG SS at the earliest and ensure their correct operation.
3. PGCIL (SR-I) to configure DR’s and EL’s of Distance Protection Relays
at Nellore-PG with suitable LEGENDs for indicating operation of type of
protections (like Zone-1, Zone-2, Zone-3, DEFR, OVR-I, OVR-II, etc.).
PendingPGCIL-SR1 Mail dated 15.12.2017:
Ferro resonance is being observed at GWK for any disturbance at Jepore
end. ABB have suggested to keep FSC in service at Jeypore end when
powerflow is more than 250MW per line. At low powers FSC is
generating resonanting frequencies & causing ferro resonance.
If SRPC advises, the FSC shall be kept out for powerflow below 500 MW
as a mitigation measure to avoid ferro-resonance.
Review Meeting dated 19.12.2017:
PGCIL (SR-I) was requested to refer the solution propsoed to their
Corporate for implementation feasibility. It was also made clear to PGCIL
(SR-I) that any issue relating to revision of FSC settings can be directly
taken up with NLDC.
PGCIL (SR-I)PGCIL (SR-I) to study the solution proposed by ABB in their paper on
“Mitigation of Ferro-resonance in Line Commutated HVDC Converter
Interconnected with Series Compensated Overhead Line Transmission
System” presented in 2016 IEEE Electrical Power and Energy Conference
(EPEC) for implementation feasibility, and furnish an Action Taken Report
w.r.t. the same.
HVDC Poles – 1 & 2 got tripped due to Auxilliary
supply failure
PGCIL (SR-I) PGCIL-SR1 Mail dated 15.12.2017 & Review Meeting dated 19.12.2017:
1. --- Pending.
2. Due to CSD contractor problem CB Y-pole reclosed & defective
contactors replaced & wiring problem in CSD rectified on next day ---
Completed.
3. NPS end DR & EL configured as suggested. --- Completed.
Tripping of HVDC Gazuwaka Pole-1 & Pole-
2
68/II/8 28-09-2017 at
17:30 hrs
68/II/12 Tripping of 400 kV NPS – Nellore-PG D/C
line
08-10-2017
at 18:58 hrs
70/II/6 Tripping of 400 kV Nellore-PG - NPS line-2 Line tripped due to mal-operation of differential
relay at NPS end and was in service from Nellore.
For the subject line, PGCIL (SR-I) to configure DR’s & EL’s of Line
Differential Relays for recording all requisite protection operations at
their Nellore PS.
PGCIL (SR-I) Yet to be Informed Pending
Annexure-III
Page 34 of 37
Complete outage of 230 kV S.P.Koil Station
of TANTRANSCO
02-04-2016 at
17:08 hrs
54/I/1
56/III/5 Tripping of 400 kV Neyveli TS-2-Pugalur
line
NLC to review the necessity of providing Relay Definitive Trip, and
accordingly take steps to disable it on all lines emanating from their
generating stations.
NLCIL Direct Trip triggering of DR wii be carried out at TS2 end during the next
planned shutdown of the Pugalur-TS2 feeder
Mail received on 22-02-2017:
Direct trip triggering of DR carried out at TS2 end for the TS2-Pugalur
feeder on 25-01-17
NLCIL Mail received on 01-12-2017:
Shut down will be requested on the Pugalur feeder from NLCTPS-2
end,the auto reclose issue and DT check will be confirmed. Checking
willbe carried out in DEC-2017.
NLCIL Mail dated 01-12-2017:
The AR circuit will be checked at TS2 end by availing a shut down and
changes will be done accordingly.
Review Meeting dated 19.12.2017:
It was agreed that A/R circuits checking, Legend renaming, and all
associated issued would be sorted out by NLCIL by availaing shutdown of
the line under reference by 20.01.2018
Pending
Others
NPCIL (MAPS)B-phase CT failure occurred in 230 kV S.P.Koil -
MAPS line-1. Busbar protection got operated at
SP.Koil station. All elements except 230kV Oragadam
and 230kV Kalivandapattu got tripped at 230kV
S.P.Koil station. ‘Y’ phase CT and support insulators
also got damaged.
1.MAPS to furnish a detailed report on the tripping of SP Koil – MAPS
lines 1 & 2 at MAPS end with focus on the correctness of the settings of
Main-I & Main-II relays (for primary & back-up protections) on both the
lines.
2.MAPS to take steps to provide down-loading facility for DR & EL from
Main-I & Main-II relays on all 230 kV lines emanating from MAPS.
3.MAPS, in co-ordination with SP Koil, to carry out PLCC end-to-end
testing, on SP Koil – MAPS lines 1 & 2, and ensure healthiness of PLCC
communication & carrier-aided protection.
4.MAPS to put in service Auto-Reclosure feature on all four 230 kV lines
emanating from MAPS by June, 2016.
PendingB phase to earth fault occurred in line. Auto-reclose
had not operated at NLC TS-2 and DT was sent to
Pugalur end resulting in a 3 phase trip
04-06-2016 at
16:36 hrs
Status revided vide MAPS mail dated 06.12.2016;
1. The settings given by M/s TANTRANSCO were adopted for Main –I &
Main- II relays for both the lines. The same settings were verified to be
same. Subsequently calibrated was done and no drift was observed. ---
Completed
2. From May 2016 onwards, the DR, EL and trip report are being sent by
mail to SRLDC, Bengaluru by MAPS. --- Completed
3. Monthly maintenance of PLCC equipments is being done by M/s
TANTRANSCO. At present PLCC telephone is not working, it is being
followed up. --- Completed
4. CVTs are planned to be procured from M/s TANTRANSCO by the end
of February 2017 and A/R will be implemented for all the lines
emanating from MAPS by July-2017 as discussed in the current SRPC
meeting on 25/11/2016. --- Pending
Status received vide MAPS mail dated 06.12.2016 & Review Meeting
dated 19.12.2017;
The CVTs procurement is in progress and the scheme (A/R) would be
implemented before 31-03-2018.
Annexure-III
Page 35 of 37
PendingStatus received vide mail dated 14.12.2017
JSWEL will configure DR’s & event lists for DT send/ Receipt for 400kV
JSWEL-Guttur Line during next opportunity / outage in concurrence with
Guttur end.
Review Meeting dated 19.12.2017:
It was noted that no JSWEL representative had come to the meeting.
The issue was discussed, and it was decided that JSWEL would complete
the recommended work by the end of December, 2017.
JSWELJSWEL to configure their end DR’s and EL’s for DT receipt/ send event
for 400 kV JSWEL – Guttur line.
Line tripped on operation of Over Voltage, Stage-1
protection at Guttur end and Direct Trip was
received at JSWEL.
Tripping of 400kV JSWEL - Guttur line 67/II/7
PendingStatus received vide mail dated 29.11.2017 & Review Meeting dated
19.12.2017:
1. All 400kv transmisisonlines relays DR time scale for a post-triggering
period of 2 sec is implemented. ----Completed
2.Time-synchronization for all lines protection relays (M1 &M2) with GPS
in their 400 kV switchyard is being implemeneted. Scheme design is in
process. ECD-April-2018 ---- Pending
NPCIL (KGS)1. KGS to properly configure all relays DR’s time scale for a post-
triggering period of 2 sec to capture events such as complete A/R
operation.
2. KGS to ensure time-synchronization of all protection relays with GPS
in their 400 kV switchyard.
B-phase to earth fault. Line did not auto-reclose at
Kaiga end.
Tripping of 400 kV Kaiga-Guttur line-162/III/2 06-02-2017
at 05:01 hrs
09-07-2017 at
18:02 hrs &
24-07-2017 at
02:05 hrs
Line tripped on Y-phase to earth fault. Line auto-
reclosed from Guttur end and failed to re-close from
Kaiga end
1. NPCIL (KGS) to furnish an action taken report on the reasons
for A/R lock-out, and remedial action taken to rectify the same.
2. NPCIL (KGS) to configure DR’s of line protection relays for a
post triggering period of 2 sec to capture complete A/R operation
at their Kaiga GS.
3.NPCIL (KGS) to furnish FIR & TR for tripping events as per SRLDC
provided formats.
HNPCL Yet to be informed
Tripping of 400 kV Kaiga-Guttur line-2 27-03-2017 at
7:06 hrs
Complete outage of 400kV TPCIL station TPCIL to configure DEF protection such that it remains in blocked
condition as long as Distance Protection is active, and becomes active
only when distance protection does not pickup.
400 kV TPCIL-Nellore PS line-1 got tripped from
TPCIL end during fault in 400kV Nellore-Nellore PS
line-2. Running units at TPCIL got tripped due to loss
of evacuating line. 400kV Nellore PG - Nellore PS line-
2 and 400kV TPCIL - Nellore PS line-1 were under
shutdown.
25-10-2017 at
19:33 hrs
69/I/1
29-09-2017 at
22:36 hrs
Tripping of 400 kV
K V KOTA - HNPCL lines – 1 & 2
68/II/11 Line-1 tripped on R-E Zone-1 fault, and the Line-2
tripped on Direct Trip receipt at KV Kota end
63/III/8 PendingStatus received vide mail dated 29.11.2017 & Review Meeting dated
19.12.2017:
1.On 27.03.17 at 07:04 hrs, 400KV Kaiga-Guttur-2(Line-2) tripped on
phase-Y to N (of R, Y, B) Zone-1 distance protection at Guttur end. Fault
distance recorded at Kaiga end was 125.9Km. During the event insulator
flash over tookplace at tower ID No. 114. At KGS line CB pole discrepacy
timer drift was observed due to which AR was not sucessfull. Pole
desrepancy timer is replaced with calibrated timer and observed
sucessful operation of auto recloser of line during subseqent trips.
---Completed
2. ----- Pending
3. NPCIL(KGS) is furnishing FIR & TR for tripping events as per SRLDC
formates. ---Completed
1. HNPCL to ensure time sync of all of their protection relays with GPS,
and to configure corresponding DR’s for post triggering time of 2
sec.HNPCL to configure DEF operation only when Distance relay does not
sense the fault.
2.HNPCL to ensure healthiness of A/R scheme implemented on all 400
kV lines at their station.
3.HNPCL to provide priority A/R scheme for 400 kV Tie-CB’s with s
suitable dead-time of say 2 sec.
4.HNPCL to revise PDR timing as 1.5 sec till implementation of A/R for
Tie-CB’s after which it shall be further revised to 2.5 sec.
5.HNPCL to implement following OVR-I gradings for the 400 kV lines
emanating from their station:
Kalpaka Line-1 7.35 A 111%, 10 sec
Kalpaka Line-2 7.35 D 110%, 8 sec
KV Kota Line-1 246 B 111%, 9 sec
KV Kota Line-2 246 G 109%, 6 sec
PendingYet to be informedTPCIL
Pending
NPCIL (KGS)
Annexure-III
Page 36 of 37
1.For the tripping of 400 kV NLC TS2 – Pugalur line, NLCIL to investigate
the reasons for sending of DT to Pugalur end, and furnish an action taken
report including remedial action taken and setting right various LEGEND
issues in DR & EL of protection relays to PCSC forum.
2. For the tripping of 400 kV NLC TS2Exp – Pugalur line, NLCIL to
investigate the reasons for 3-ph tripping (detection of the fault as Y-B-E)
of the line from NLC TS2Exp end including verifying pertinent settings of
P437 relay (reference may be made to explanation given by TPCIL in GD -
I.1/
GD - I.2), and furnish an action taken report including remedial action
taken and setting right various LEGEND issues in DR & EL of protection
relays to PCSC forum.
Protection at NLCTS-2 & NLCTS-2 Exp has sensed as
R-Y-E fault and given a 3 phase trip. At Pugalur end
protection has sensed fault as Y-N and B-N fault in
400kV Neyveli TS2-Pugalur line & 400kV Neyveli TS2
EXP-Pugalur line respectively. Breaker at Pugalur got
tripped due to Direct Trip receipt.
10-10-2017 at
23:54 hrs
Tripping of 400 kV Neyvelli TS2 – Pugalur
and 400 kV Neyvelli TS2 (exp) – Pugalur
line
69/II/9 NLCIL Yet to be informed Pending
Annexure-III
Page 37 of 37
Sl.No. Element NameOutage
date/time
Revival
date/timeReason for Outage Sender/ Receiver
Remedial Measures/ Actions taken
1 400/220 Kv ICT-1 AT BIDADI 16-09-2017/04:56:00 OIL LEAKAGE PGCIL(SR-II) To-be-discussed
2 765/400 ICT-2 AT VEMAGIRI-PG 19-09-2017/02:04:00 B PHASE LA BLAST PGCIL (SR-I) To-be-discussed
3 765/400 KV NIZAMABAD ICT-1 03-10-2017/07:33:00 03-10-2017/22:50:00DIFFERENTIAL PROTECTION
OPERATEDPGCIL( SR-I)
To-be-discussed
4 400 KV KAYATHAR - KARAIKUDI 04-10-2017/02:18:00TRIPPED ON SWITCH ON TO
FAULTTANTRANSCO/ PGCIL( SR-II)
TANTRANSCO: Temporary Line fault.
AR operated. Subsequently feeder
tripped on SOTF.
TANTRANSCO: Temporary Line fault.
AR operated. Subsequently feeder
lockout.
PGCIL (SR-II): Due to Persisiting Fault,
Auto Reclose not attempted. Line
Ownership by TANTRANSCO.
5 400 kV VIJAYAWADA - VTPS ST IV 04-10-2017/03:52:00 R phase to Ground fault APTRANSCO/ APGENCOAPTRANSCO: Not pertaining to
APTRANSCO
6 400kV SURYAPET -MALKARAM 12-10-2017/17:54:00 R-N FAULT TSTRANSCO
TSTRANSCO:Tripped at both ends.
Tripped on Y-Phase to ground
indications. A/R acted and
unsuccessful at both ends.
7 400 kV VEMAGIRI - SIMHADRI 2 13-10-2017/12:59:00 13-10-2017/14:24:00 DISTANCE PROTECTION APTRANSCO/ NTPC (Simhadri )
APTRANSCO: Feeder tripped on B-Ph,
Z1, indications. A/R unsuccessful due
to persistent fault.
8 HVDC BHADRAVATHI POLE 2 13-10-2017/16:28:00 13-10-2017/17:09:00TRIPPED ON PLCC CARD
FAILUREPGCIL( SR-I)/ PGCIL (WR-I)
To-be-discussed
9 220 kV KAIGA - KADRA 1 13-10-2017/14:49:00 DISTANCE PROTECTION NPCIL (KGS)/ KPTCL
KPCL:
Kadra - Kaiga line tripped at kadra end
on carrier aided protection trip. Line
distance 13 KM. The fault distance
recorded in relay is 11.85KM(i.e zone-
2 region from kadra). At kadra end
zone-2 started in numerical relay but
carrier signal received from kaiga end.
Hence kadra end breaker tripped in
carrier aided protection with zone-1
timimg. The relay operation is found
to be OK.
Pending Remedial Measures/ Actions taken
for the Critical Tripping Incidents (as on 05.01.2018)
Annexure-IV
Page 1 of 5
10 400 kV KHAMMAM - ASUPAKA 13-10-2017/11:13:00 Y-N FAULT PGCIL(SR-I)/ TSTRANSCO
TSTRANSCO: Tripping element is
400kV Asupaka-Kalpaka line. Tripped
at both ends. Tripped on Y-Phase to
ground indications. A/R acted and
unsuccessful at Asupaka end.
11 220 kV AMBEWADI - PONDA 2 14-10-2017/12:52:00 14-10-2017/18:19:00 DISTANCE PROTECTION KPTCL/ GEDTo-be-discussed
12765 KV NIZAMABAD -
MAHESHWARAM - 218-10-2017/13:06:00
DT RECEIVED AT NIZAMABAD
ENDPGCIL (SR-I)
To-be-discussed
13 400/220 Kv ICT-1 AT PALAKKAD 22-10-2017/01:03:00 BUCHHOLZ RELAY OPERATED KSEB/ PGCIL (SR-II)
KSEBL:
400/110kV ICT-1 at Palakkad is owned
by PGCIL at 400kV S/S Elappully
(Palakkad).The details may please be
sought from PGCIL.As this is not in the
scope of KSEBL, necessary correction
may be made in the records.
PGCIL (SR-II):
14 220 kV AMBEWADI - PONDA 1 22-10-2017/11:34:00 22-10-2017/11:55:00 mal operation KPTCL/ GED To-be-discussed
15 220 kV AMBEWADI - PONDA 1 22-10-2017/11:34:00 22-10-2017/11:55:00 mal operation KPTCL/ GED To-be-discussed
16 HVDC BHADRAVATHI POLE 2 25-10-2017/09:48:00 25-10-2017/16:56:00TRIPPED ON GATE UNIT
POWER SUPPLY FAILUREPGCIL(SR-I)/ PGCIL (WR-I)
To-be-discussed
17 400 Kv NTPL - TTRNPS 25-10-2017/12:01:00 TRIPPED ON R-B-N FAULT NTPL/ PGCIL (SR-II)
PGCIL (SR-II):
Line Auto Reclosed and tripped due to
persisiting Fault. It was gathered that
problem at NTPL Switch Yard.
PGCIL(SR-II)
Line Auto Reclosed and tripped due to
persisiting Fault. It was gathered that
problem at NTPL Switch Yard (In B-ph
Gas Insulated Bus Duct IR value
observed to be zero and Sf 6 leakage
observed at NTPL GIS.)
NTPL:
Annexure-IV
Page 2 of 5
18 400kV VTPS -MALKARAM 01-11-2017/11:56:00 R-N FAULT APGENCO/ TSTRANSCO
TSTRANSCO:Tripped at both ends.
Tripped on R-Phase to ground
indications at Malkaram end. Auto
reclosure acted and successful at
Malkaram end.
APGENCO:
19 220 kV KANIAMPET - KADAKOLA 05-11-2017/10:25:00 05-11-2017/12:08:00TRIPPED ON RELAY MAL-
OPERATIONKSEB/ KPTCL
KSEBL:
On 5th Nov 2KDKN feeder tripped
from Kadakola end. At Kaniyambetta
end there was no tripping, hence DR&
EL is not available from Kaniyambetta.
This feeder was radially fed from
Kadakola and as there was no supply
from Kaniampetta side, the non
operation of relays is in order. This
may be removed from the list for
Pending Remedial Measures/ Actions
taken for the Critical Tripping
Incidents as there is no abnormality in
the incident.
KPTCL:
20 400 KV KALPAKA - ASUPAKA 05-11-2017/18:30:00 PHASE TO PHASE FAULT APTRANSCO/ TSTRANSCO
TSTRANSCO:
Trippedat both ends. Tripped on R to
Y-Phase indications at Asupaka end.
APTRANSCO : Feeder tripped on R&B
Ph,Z2 indications at Kalapaka end.
Hence A/R unsuccessful due to Ph to
Ph fault.
21 220 kV AMBEWADI - PONDA 1 09-11-2017/13:42:00 09-11-2017/17:31:00 TRIPPED ON C-N FAULT KPTCL/ GED To-be-discussed
22 220 kV AMBEWADI - PONDA 2 09-11-2017/14:31:00 09-11-2017/18:21:00 DISTANCE PROTECTION KPTCL/ GEDTo-be-discussed
Annexure-IV
Page 3 of 5
23 400 kV MALKARAM - HYDERABAD 16-11-2017/12:02:00 16-11-2017/12:11:00TRIPPED during 411 BAY
TESTINGTSTRANSCO/ PGCIL (SR-I)
TSTRANSCO: Line did not trip and
everything is normal at Malkaram
PGCIL (SR-I):
24 220 kV AMBEWADI - PONDA 2 29-11-2017/14:37:00 TRIPPED ON OCR RELAY KPTCL/ GED (WR)To-be-discussed
25 400kV VTPS -MALKARAM 05-12-2017/10:45:00 05-12-2017/11:51:00 DT RECEIVED APGENCO/ TSTRANSCO
TSTRANSCO: Tripped at Both ends.
Tripped on Direct Trip received
indications at Malkaram end. Other
end tripped on Over Voltage.
APGENCO:
26 400KV VTPS-SURYAPET 05-12-2017/10:45:00 05-12-2017/16:04:00 THREE PHASE FAULT APGENCO/ TSTRANSCO
TSTRANSCO:
Tripped at Both ends. Tripped on Y to
B phase, Z2 indications at Suryapet
end.
APGENCO:
27 765/400 Kv ICT-2 at NPS 05-12-2017/18:41:00 06-12-2017/05:20:00 BUCHOLZ RELAY OPERATED PGCIL (SR-I)To-be-discussed
28 400KV/220KV DICHPALLY-ICT-3 08-12-2017/10:23:00 08-12-2017/14:58:00 To take IR values TSTRANSCOTo-be-discussed
29 765KV/440KV KURNOOL_PG-ICT-2 08-12-2017/10:53:00 08-12-2017/13:50:00TRIPPED ON BUCCHOLZ RELAY
OPERATIONPGCIL (SR-I)
To-be-discussed
30400KV-NAGAPATTNAM_PS-
DHARMAPURI-1 400KV13-12-2017/13:24:00 13-12-2017/13:36:00
Fault in switch yard at
DharmapuriPGCIL(SR-II)
To-be-discussed
31400KV-NAGAPATTNAM_PS-
DHARMAPURI-2 400KV13-12-2017/13:24:00 13-12-2017/13:36:00
Fault in switch yard at
DharmapuriPGCIL(SR-II)
To-be-discussed
32400KV-MAHESHWARAM_TG-
SHANKARAPALLY-215-12-2017/12:29:00 15-12-2017/12:41:00 TSTRANSCO
To-be-discussed
33 400KV/220KV HOODY-ICT-2 15-12-2017/19:02:00 TRIPPED ON LA BLAST KPTCLTo-be-discussed
34 400KV/220KV HOODY-ICT-1 15-12-2017/19:02:00 15-12-2017/19:38:00 TRIPPED ON LA BLAST KPTCLTo-be-discussed
35 400KV/220KV HOODY-ICT-3 15-12-2017/19:12:00 15-12-2017/19:36:00TRIPPED ON
OVERLOADINGKPTCL
To-be-discussed
36 230KV-NEYVELI_TS_II-BAHOOR-2 17-12-2017/10:45:00 DISTANCE PROTECTION NLCIL/ PEDTo-be-discussed
Annexure-IV
Page 4 of 5
37 400KV-GHANAPUR-GAJWEL-1 18-12-2017/14:19:00 18-12-2017/15:38:00DT RECEIVED FROM
GAJWAL ENDPGCIL (SR-I)/ TSTRANSCO
To-be-discussed
38 400KV-KAIGA-NARENDRA-1 20-12-2017/09:34:00 EMERGENCY MAINTAINANACE NPCIL (KGS)/ KPTCLTo-be-discussed
39400 kV Mamidipalli - Khammam Line-
221-12-2017/11:38:00 21-12-2017/13:57:00 Tripped on R-N Fault TSTRANSCO/ PGCIL (SR-I)
To-be-discussed
40 400KV-SURYAPET-KV_KOTA-1 22-12-2017/12:27:00 B PHASE TO GROUND FAULT TSTRANSCO/ APTRANSCOTo-be-discussed
41 400KV-HINDUJA-KV_KOTA-2 26-12-2017/12:34:00 26-12-2017/14:10:00 R-N FAULT HNPCL/ APTRANSCOTo-be-discussed
42 400KV-MALKARAM-VTPS_IV-1 27-12-2017/14:39:00 27-12-2017/15:42:00 MAL-OPERATION TSTRANSCO/ APGENCOTo-be-discussed
43 400KV-GUTTUR-HIRIYUR-1 28-12-2017/07:37:00 28-12-2017/18:29:00 CVT Problem KPTCL/ PGCIL (SR-II)To-be-discussed
44 220KV-ELAPULLY-MADAKATHARA-1 29-12-2017/14:56:00 TRIPPED ON LBB OPERATION KSEBLTo-be-discussed
45 400KV-GAUTAMI-VEMAGIRI_AP-2 29-12-2017/12:14:00 SWAPPING GVK/ APTRANSCOTo-be-discussed
46 400KV-GVK-VEMAGIRI_AP-1 29-12-2017/12:17:00 SWAPPING GVK/ APTRANSCOTo-be-discussed
47 400KV/220KV MADAKKATHARA-ICT-1 29-12-2017/14:56:00 29-12-2017/15:54:00 TRIPPED ON LBB OPERATION KSEBLTo-be-discussed
48 220KV-AMBEWADI-PONDA-1 30-12-2017/08:02:00 30-12-2017/13:08:00H/T FOR AIR COMPRESSOR
PROBLEMKPTCL/ GED
To-be-discussed
49 400KV-KALPAKKA-ASUPAKA-1 31-12-2017/12:41:00 31-12-2017/18:30:00TRIPPED ON A PHASE TO
GND FAULTAPTRANSCO/ TSTRANSCO
To-be-discussed
50 400KV/220KV NARSAPUR-ICT-1 31-12-2017/14:49:00 PRV OPERATED TSTRANSCOTo-be-discussed
51 400KV-GVK-VEMAGIRI_AP-1 03-01-2018/12:09:00 swapping GVK/ APTRANSCOTo-be-discussed
52 400KV-GAUTAMI-VEMAGIRI_AP-2 03-01-2018/16:30:00 swapping GVK/ APTRANSCOTo-be-discussed
Annexure-IV
Page 5 of 5
70th Protection Co-ordination Sub-Committee Meeting
18th December 2017
Annexure-V
Page 1 of 18
1. Tripping of 400/220kV ICT-1 at Guttur substation at 08:42 hrs
on 07-11-2017
• As per FIR, ICT tripped due to CB Low SF6 gas pressure
• Antecedent Flow: 96 MW / 15 MVAr
• Findings & remedial measures taken may be furnished
Annexure-V
Page 2 of 18
2. Tripping of 400kV Srisailam – Kurnool line during
November 2017
• Line tripped on operation of over-voltage protection at Srisailam and direct trip was received at
Kurnool.
• Considerable voltage difference was observed between R, Y & B phases at both ends.
• Voltages recorded in DR:
Date and Time Srisailam End Kurnool End
07-11-2017 at 23:02 hrs Vr-257kV , Vy-246kV , Vb-239kV Vr-243kV , Vy-261kV , Vb-248kV
09-11-2017 at 21:57 hrs Vr-261kV , Vy-249kV , Vb-235kV Vr-245kV , Vy-246kV , Vb-272kV
12-11-2017 at 20:54 hrs DR not submitted Vr-274kV , Vy-279kV, Vb-237kV
17-11-2017 at 21:19 hrs Vr-257kV , Vy-252kV , Vb-234kV Vr-235kV , Vy-264kV, Vb-278kV
Annexure-V
Page 3 of 18
Annexure-V
Page 4 of 18
3. Tripping of 400kV Srisailam – Sattenapalli line on
11th, 12th and 24th Nov 2017
• Line tripped on operation of over-voltage protection at Srisailam and direct trip was received
at Sattenapalli.
• Considerable voltage difference was observed between R, Y & B phases at Srisailam end.
• Minutes of 69th PCSC meeting held on 23rd Nov 2017. - R-ph CVT would be replaced. Procurement under progress
Date and Time Srisailam end Sattenapalli end
11-11-2017 at 22:02 hrs Vr-231kV , Vy-249kV , Vb-254kV Vr-245kV , Vy-245kV, Vb-243kV
12-11-2017 at 23:09 hrs Vr-231kV , Vy-249kV , Vb-254kV Vr-246kV , Vy-247kV , Vb-243kV
24-11-2017 at 18:46 hrs Vr-228kV , Vy-250kV , Vb-257kV Vr-244kV , Vy-250kV, Vb-243kV
Annexure-V
Page 5 of 18
4. Tripping of 400/220kV ICT-2 at Dindi substation on 11th and 26th Nov 2017
• As per FIR, ICT Tripped on mal operation of Buchholz relay.
• Remedial actions taken may be apprised at the forum.
Annexure-V
Page 6 of 18
5.Multiple Tripping at 220kV Talaguppa station at 12:10 hrs on 13-11-2017
Triggering Incident: LBB protection operated in 220 kV Talguppa-Sharavathy line-2 at Talaguppa end.
Elements connected to Bus-1 got tripped: i. 400/220kV ICT 1,2 & 3 ii. 220kV Talaguppa – Sharavathy 1 & 2 iii. 220kV Talaguppa – Gerusoppa 1 & 2
Load / Generation Loss : NIL
Annexure-V
Page 7 of 18
PMU data plot:
• Observations from Talaguppa end DR
• Current was observed in R, Y, B phase and neutral for 420ms. • Fault current in DR : Rph- 201A, Yph-118A, Bph-117A
• Dip in R, Y & B phase voltages was also observed in PMU data plot.
Annexure-V
Page 8 of 18
6. Tripping of 400kV Nellore-NPS line-2 at 13:06 hrs &
14:26 hrs on 24-11-2017
• Line tripped due to mal-operation of differential at NPS end.
• Line was in service from Nellore end.
• LDP relay was commissioned in place of Main-1 Distance relay on 23.11.2017 at both ends.
• Remedial measures taken may be furnished.
Annexure-V
Page 9 of 18
7. Multiple Tripping at 230kV Madurai Substation at
12:10 hrs on 24-11-2017
Triggering Incident: Spurious initiation of LBB leading to operation of bus bar protection Elements Tripped: i. 230kV Madurai – Sembatty, ii. 230kV Madurai – Kinnimangalam, iii. 230kV Madurai – TTPS, iv. 230kV Madurai – Meelavittam, v. 230kV Madurai – Ind Bharath, vi. 230kV Madurai – Nallamanaickanpatty, viii. 230kV Madurai – Kayathar, ix. 230kV Madurai – Renganathapuram, x. 230kV Madurai – Pasumalai, xi. 230kV Madurai – Theni and Xii. 400/230kV ICT-1 & 2. No load loss reported.
Annexure-V
Page 10 of 18
PMU data plots
From the PMU plots it can be observed that fault was not there. The was no change in the negative or zero sequence currents.
Annexure-V
Page 11 of 18
8. Tripping of 400/220kV ICT-1 at Talaguppa on 25-11-2017 at
16:29 hrs and on 30-11-2017 at 18:09 hrs
• On both days ICT-1 at Talaguppa tripped due to mal operation of R-phase backup over current relay.
• No Fault was observed from PMU data plots.
• Remedial measures taken may be furnished.
Annexure-V
Page 12 of 18
9. Tripping of 400/220kV ICT-3 at Vijaywada (Nunna) on 27-11-2017 at 00:52 hrs and on 29-11-2017 at 00:47 hrs
• 400/220kV ICT-3 at Vijaywada tripped on operation of over-flux protection.
• The V/f calculated from PMU data plot was 1.10% (approx.)- LV side
Annexure-V
Page 13 of 18
10. Multiple Tripping at 220kV Guttur substation at 09:03 hrs on 30-11-2017
• Triggering Incident: • Y-phase jumper snapping in Jogihally Bay from Bus-1 to Bus isolator at guttur station
resulting in operation of bus bar protection
• Elements tripped: All Elements connected to Bus-1 got de-energized.
• Load loss : Nil
400 kV Bus 1
JSW 220kV Bus 2
Beeranahally
315MVA ICT-1
180MW
Munirabad
117
Narendra
2X30MW
Kaiga 2 X 2X84MW
400kV Bus-2
2
1
2
220kV Bus 1
2 X 214MW
Jogihally
Chitradurga
Neelagundaa
Ranebennur
Haveri 1 &2
Davanagere
2 &3
315MVA ICT-2
46MW
Annexure-V
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PMU data plots
• From the PMU data plots it can be observed that it was two phase to ground (Y-B to ground) fault.
• Fault got cleared in 120 msecs.
Annexure-V
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11. Multiple element Tripping at 400/220kV Ghanapur (Hyderabad) substation at 12:02 hrs on 30-11-2017
• Triggering incident: Fault in 220kV Ghanapur – Hayatnagar feeder -2.
• Bus bar protection operated – suspected Maloperation
• Elements tripped: All elements connected to 220kV Bus-2 got tripped
• FIR, DR/EL not yet to furnished by TSTRANSCO
• No load loss reported.
Annexure-V
Page 16 of 18
Failure or non-operation of Auto reclose during transient fault
Sr. No. Element Date & Time Reason Sending end Receiving end
1
Tripping of 220kV Kaniyampeta-Kadakola line.
01-11-2017 at 19:32 hrs
B-phase to earth fault had occurred in line. Breakers got tripped at Kadakola
EL not furnished
2 Tripping of 400kV N’Sagar-Cudappah line.
06-11-2017 at 3:27 hrs
B-phase to earth fault had occurred in line due to insulator de-capping. Voltage was persistent in R and Y phase at Cudapah end after A/r attempt
3 Tripping of 400kv NCTPS-Manali line.
11-11-2017 at 7:18 hrs
Line tripped on R-phase to earth fault. At Manali end Auto reclose was Successful and at NCTPS end A/R is not in service.
4 Tripping of 400kV Ramagundam-Chandrapur line-2
15-11-2017 at 13:17 hrs
R-phase to earth fault had occurred in line. line auto-reclosed at Ramagundam end
Annexure-V
Page 17 of 18
Tripping at one end/ PLCC mal-operation
Sr. No. Element Date & Time Reason Sending end Receiving end
1 Tripping of 400kV Kaiga-Guttur line-2
01-11-2017 at 9:22 hrs & at 6:17 hrs on 02-11-2017
Line tripped on direct trip receive at both Kaiga and Guttur
2
Tripping of 400kV Maheshwaram(TS)-Maheshwaram (PG)-1&2 and 400kV Maheshwaram(TS)-Shankarapalli-1&2
02-11-2017 at 11:32 hrs
Lines got tripped due to suspected DC earth at Shankarapally. All these lines are connected to 400kV Bus-1 at Maheshwaram TS
Maheswaram PG end DR/EL only available for 400kV MaheswaramPG-MaheswaramTS ckt-1&2
3
Tripping of 400kV Ramagundam-Gajwel line
21-11-2017 at 17:17 hrs
Line tripped on direct Trip receive indications at Gajwel end only and was in service from Ramagundam
DR/EL not furnished
DR/EL not furnished
Annexure-V
Page 18 of 18