· minutes of the 70th meeting of pcsc held on 18th december, 2017 page 2 3. details of grid...

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



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



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



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



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



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



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

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


As per TANTRANSCO report dated 13.12.2017:

TANTRANSCO informed that the above works were completed on 14.12.2017.

Annexure-II


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


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.


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:


No Tripping Files (FIR/DR/EL/TR) furnished.


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:




As per FIR/DR/EL, line tripped at 21:59:37.841 hrs on receipt of DT.

Annexure-II


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:



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:


As per FIR/DR/EL/TR, line tripped at 23:09:27.898 hrs due to OVR-I (8sec) operation.


As per FIR/DR/EL/TR, line tripped at 23:09:27.940 hrs on receipt of DT from the remote end.

Annexure-II


Tripping on 24.11.2017:




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


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.


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


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


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


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


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


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


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


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


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


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


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


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


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


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


Single Line Diagram of 220 kV Talaguppa SS of KPTCL (Ref: II.5)

Annexure-II


Single Line Diagram of 230 kV Madurai SS of TANTRANSCO (Ref: II.7)

Annexure-II


Single Line Diagram of 400/ 220 kV Guttur SS of KPTCL (Ref: II.10)

Annexure-II


Single Line Diagram of 220 kV Hyderabad (Ghanapur) SS of KPTCL (Ref: II.11)

Annexure-II


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


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


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: 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.


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


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.


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


PGCIL may be requested to take necessary action


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.


2. APTRANSCO is to replace the faulty/outdated relays & POWERGRID

has to maintain the relays after retrofitting.


2. APTRANSCO informed that the recommended works would be

completed in one-month period.

PGCIL (SR-I)/

TSTRANSCO


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.


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.


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.


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


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


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]


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


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


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.


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.


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:





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


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


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.


Issue was addressed to the concerned for necessary action.


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.


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.


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.





priority through GE Ltd.


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:





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 Unit

Pending

[with TANTRANSCO]

Complete outage of North Chennai TPS

STG-2


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.


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 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.






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.






2018.



(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


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


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.






2018.



(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:





replaced.

NTPC-Ramagundam/

TSTRANSCO/

PGCIL (SR-I)


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


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


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


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:





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


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


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


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.


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


PGCIL (SR-I) informed that they are waiting for written confirmation from


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.






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


TSTRANSCO in coordination with NTPC-Ramagundam:





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


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


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.


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


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


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.


59/IV/3 For the line under consideration, the following shall be carried out by

TSTRANSCO in coordination with PGCIL (SR-I):





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.


Letter is been given to field for conducting end to end testing of 400kV

Gajwel-Ghanapur line.


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


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


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


replaced.

(ii) End-to-end communication for DT/ permissive & other signals may be


(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.


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.


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


3. Providing 2 separate DC sources is under process --- Pending


3. Work under implementation stage --- Pending


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


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


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.


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

.


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


Tendering under process


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.


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 coordination with EE(RT), KPTCL, Hubli.


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


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


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


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


1),3),4) Completed

2. Auto Start of DG set is taken up --- Pending


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.


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


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


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.


Carrier protection is being restored for 220kV Sedam-Tandoor line at

Sedam end. After restoring the carrier protection , AR will be enabled.


SEE,SCADA to update the latest status


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.





priority through GE Ltd.


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


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.




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


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.


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.



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



stage.



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


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


1. Bus Bar protection will be provded under R&U.

2. A/R yet to be enabled.



stage.




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.


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.


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.


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.


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.


GPS and accessories will be supplied during May 2017, expected to

complete the work within a month after supply of materials.


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.


Enabling the AR feature was discussed during PCSC meetings and since




the Back Up EFR timings have been reducedto 150mS.


Enabling the AR feature was discussed during PCSC meetings and since




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.


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


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


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


SEE, RTC, Bangalore to update the status


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.


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.


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.


Replacement of existing BBP by new BBP with 4 zone protection is being

taken up under R&U.


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.


Due to operational constraints two/ multi bus operation is not being

implemented.


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.


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


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:



February, 2018.

Pending

KPTCL mail received dated 25.04.2017:

Numerical BBP is being provided under R&M works


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.


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.


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


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


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


2. Modifications to be carried in Nagzari SPS logic is submitted to

SRLDC/SRPC for verification and approval


1. Will be reviewed in consultation with EE(RT), KPTCL, Hubli.

3. Both the lines are in charged condition.


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


1) & 3). --- Completed.


SRLDC/SRPC., yet to be discussed and approved by the SRPC forum ---

Pending


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.


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.


Modifications to be carried in Nagzari SPS logic is submitted to

SRLDC/SRPC for verification and approval


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.


2. Proposed revision in existing SPS scheme is already submitted to

SRLDC/SRPC., yet to be discussed and approved by the SRPC forum. ---

Pending


1) & 3). --- Completed.


SRLDC/SRPC., yet to be discussed and approved by the SRPC forum ---

Pending


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


1) Check zone New Relay is replaced on 17.04.2017 -- Completed.

2. --- Pending

3. --- Pending


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


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.


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


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:



Main-1 & 2 relays will be replaced for the requirement of more output

contacts for AR logic implementation.


is being provided.

TANTRANSCO mail dated 04.08.2017:






is provided. ----- Completed

TANTRANSCO mail dated 18-09-2017 & 31-10-2017.






is provided at NCTPS-II . -----Completed



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


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:




12.04.2017 & 01.06.2017 & 15-06-2017 & 04.08.2017:



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.


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.


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:


end. Tender floated for relay procurement.


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.


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.



works to accomodate bus coupler bay. Numerical BBP relay has been

provided and tesing under progress.



works to accomodate bus coupler bay.

Numerical BBP relay was commissioned onj 29.08.2017.

Pending


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


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.


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.


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.


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..


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


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.


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


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


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 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)


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


1. Purchase procedures is still in progress --- Pending

2. Replaced. --- Completed.

3. PLCC equipment Tested and found OK --- Completed.


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:


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

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:


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


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.


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


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.


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.


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

GI/07_11_2017_400-220kV ICT-2 at Guttur/220kV end DR.pdf

GI/07_11_2017_400-220kV ICT-2 at Guttur/220kV end EL.pdf

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


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

GI/07,09,12,17_11_2017_400kV Kurnool-Srisailam/7th/Srisailam end_DR_07Nov.pdf

GI/07,09,12,17_11_2017_400kV Kurnool-Srisailam/7th/Kurnool end_DR_07Nov.pdf






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




Annexure-V

Page 5 of 18

GI/11,12,24_11_2017_400kV sattenpalli-Srisailam/11th/Srisailam end_DR_11Nov.pdf



GI/11,12,24_11_2017_400kV sattenpalli-Srisailam/11th/sattenpalli end_DR_11Nov.pdf

GI/11,12,24_11_2017_400kV sattenpalli-Srisailam/12th/Sattenpalli end_DR_12Nov.pdf

GI/11,12,24_11_2017_400kV sattenpalli-Srisailam/24th/Sattenapalli end_DR_24Nov.pdf

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

GI/13-11-2017_22kV Talaguppa SS/talaguppa DR.pdf

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

GI/24-11-2017_400kV Nellore-NPS/NPS end_DR.pdf

GI/24-11-2017_400kV Nellore-NPS/NPS end_EL.pdf

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

GI/24-11-2017_230kV Madurai SS/230kV Madurai end_DR.pdf

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

GI/27&29_11_2017_ICT3 at Vijaywada/HV end DR_27Nov.pdf

GI/27&29_11_2017_ICT3 at Vijaywada/HV end DR_29Nov.pdf

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

Page 14 of 18

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

Page 15 of 18

GI/30-11-2017_220kV Guttur/Guttur_DR.pdf

GI/30-11-2017_220kV Guttur/Guttur_EL.pdf

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

AR/01_11_2017_220kV Kaniyampeta-Kadakola/Kaniyampeta end_DR.pdf

AR/01_11_2017_220kV Kaniyampeta-Kadakola/Kaniyampeta end_EL.pdf

AR/06_11_2017_400kV NSagar - Cudappah/NSagar end_DR.pdf

AR/06_11_2017_400kV NSagar - Cudappah/NSagar end_EL.pdf

AR/11_11_2017_400kV NCTPS-Manali/NCTPS end_DR.pdf

AR/11_11_2017_400kV NCTPS-Manali/NCTPS end_EL.pdf

AR/15_11_2017_400kV Ramagundam-Changrapur2/Ramagundam end_DR.pdf

AR/15_11_2017_400kV Ramagundam-Changrapur2/Ramagundam end_EL.pdf

AR/01_11_2017_220kV Kaniyampeta-Kadakola/Kadakola end_DR.pdf

AR/06_11_2017_400kV NSagar - Cudappah/Cuddapa end_DR.pdf

AR/06_11_2017_400kV NSagar - Cudappah/Cuddapa end_EL.pdf

AR/11_11_2017_400kV NCTPS-Manali/Manali end_DR.pdf

AR/11_11_2017_400kV NCTPS-Manali/Manali end_EL.pdf

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

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/1st_Kaiga end DR.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/1st_Kaiga end EL.pdf

PLCC/02_11_2017_400kV Maheswaram/400kV MaheswaramPG-MaheswaramTS1/MaheswaramPG end DR.pdf

PLCC/02_11_2017_400kV Maheswaram/400kV MaheswaramPG-MaheswaramTS1/MaheswaramPG end EL.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/1st_Guttur end DR.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/1st_Guttur end EL.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/2nd_Kaiga end DR.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/2nd_Kaiga end EL.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/2nd_Guttur end DR.pdf

PLCC/1st&2nd_11_2017_400kV kaiga-Guttur2/2nd_Guttur end EL.pdf

PLCC/02_11_2017_400kV Maheswaram/400kV MaheswaramPG-MaheswaramTS2/MaheswaramPG2 end_DR.pdf

PLCC/02_11_2017_400kV Maheswaram/400kV MaheswaramPG-MaheswaramTS2/MaheswaramPG2 end_EL.pdf

· minutes of the 70th meeting of pcsc held on 18th december, 2017 page 2 3. details of grid...

Documents