SOUTHERN REGIONAL POWER COMMITTEE
BENGALURU
Minutes of the 50th Meeting of Protection Coordination Sub-Committee
(PCSC – 50) of SRPC held on 27.01.2016
1. Introduction
The 50th meeting of Protection Coordination Sub-Committee (PCSC-50) was held on 27th January,
2016 in Trivendrum, Kerala. The list of participants is enclosed at Annexure-I.
Sh. J. Mammen, GM (Commercial), NTPC extended warm welcome to Sh. S.R. Bhat, Member
Secretary (MS), SRPC, Sh. G. Anbunesan, AGM, SRLDC, and other Officials from State & Private
Power Utilities, SRLDC and SRPC. He thanked MS, SRPC for giving them an opportunity to host
PCSC meeting, and added that ‘Team NTPC’ had put in all efforts to ensure a comfortable and
pleasant stay for all participating members.
Sh. S.R.Bhat, Member Secretary (MS), SRPC thanked Sh. Venkateshwaran, Regional Executive
Director (South), NTPC & NTPC-Kayamkulam management for the excellent hospitality, and all
the due care they have taken in making arrangements for the smooth conduct of the meeting.
He then welcomed the Members and Participants to the meeting and briefed them on the
following points:
 Informed members that Protection Audit Review of Stations (15 in number) under Task-2
by the Consultant had commenced. Already five Stations, viz., Hosur, Gajuwaka, Alamathy,
Tirunelveli & Edamon, were audited during Dec, 2015 – Jan, 2016. Out of the remaining
ten stations, five Stations (NLC TPS-II, Nelamangala, Gooty, Kurnool & NTPC-Ramagundam)
would be audited in February, 2016, and the remaining five Stations (Guttur, Kaiga,
Raichur, Sharavathy & Kottagudem) would be audited in March, 2016. He requested
Constituents’ active cooperation in completing Task-2 activities to the satisfaction of all
parties involved.
 Reminded members of completion of dead-lines of time-extensions given to various SRConstituents by Hon’ble CERC for completion of their respective Protection Audit Remarks
(PAR). In this regard, all SR-Constituents (Genco’s, Transco’s & IPP’s) were requested to
kindly furnish the status of their respective pending protection audit remarks, and the
act ion taken by them in terms of obtaining further time-extensions & the measures taken
to implement their respective PAR latest by 31.01.2016 for filing a consolidated reply
before Hon’ble CERC.
 Informed members that in pursuance with the decision taken in 26 th SRPC meeting, steps
had been initiated to procure Protection Suite (Protection Management System) that
comprises web-based management software and protection setting calculation tool
through PSDF funding. The detailed scope of the work is enclosed at Annexure-II. The
number of license per utility required for Southern Region is listed below:
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 1
S.No
Utility
Quantity
1
Karnataka
6
2
Tamil Nadu
8
3
Andhra Pradesh
4
4
Telangana
4
5
Kerala
4
6
Puducherry
1
7
Power Grid
2
8
NPCIL
1
9
NTPC
1
10
NLC
1
11
SRLDC
1
12
SRPC
2
Total
35
After obtaining approval for PSDF funding, tendering process for executing Protection
Suite would be initiated.
 Apprised members of the findings/ recommendations of Protection System Analysis Group
(PSAG-14) meeting held at MAPS, Kalpakkam on 16.12.2016, and requested TANTRANSCO
& MAPS to take steps to implement them to prevent recurrence of GD’s around MAPS.
 Brought to members’ attention the obligation of fulfilling their requirements under
Regulation 5.2 I of IEGC, as per which all Users, STU/ SLDC, and CTU are required to furnish
for analysis purpose the relevant information relating to tripping events in their system
along with Disturbance Recorder (DR) and Event Logger (EL) to SRLDC/ SRPC within 24-hrs
of occurrence of the same. Though this issue was regularly brought to Constituents’
attention vide various SRLDC & SRPC (fort-nightly) letters, still data w.r.t. all events was
either not being furnished or being made available with unacceptable delay of few weeks.
Constituents were urged to strictly comply with Regulation 5.2 I of IEGC, and furnish the
data in time.
22. Confirmation of the Minutes of the 49th PCSC meeting held on 30.11.2015
SE (Protection), SRPC stated that the Minutes of the 49th meeting of the PCSC had been
circulated vide SRPC letter No. SRPC/SE-III/ PCSC-49/ 2015/ 8871 – 9003 dated 14.12.2015. As
no observations had been received from any of the Constituents, the Minutes of the 49th
meeting of PCSC were confirmed.
3. Details of Grid Disturbances (GD’s), Grid Incidents (GI’s), Line Trippings due to Auto-Reclose
non-operation and PLCC mal- operation.
Minutes of the 50th PCSC Meeting held on 27-01-2016
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The trippings due to GD’s, GI’s, Auto-Reclosure failure/ non-operation, and PLCC mal-operation
that had occurred during the period November, 2015 - January, 2016 were discussed in the
Meeting. The deliberations and recommendations of the PCSC-forum are enclosed at
Annexure–III.
4. Status of pending PCSC recommendations
The status of implementation of pending PCSC recommendations was discussed in the meeting.
The Constituents had been requested to kindly submit the status of their compliance latest by
22-02-2016. The updated status of the same as on 11-02-2016 is enclosed at Annexure–IV.
5. Remedial measures/ Action taken for the tripping incidents of the transmission elements
under forced outage
The tripping incidents of the transmission elements under forced outage for which the remedial
measures/ actions taken still awaited were discussed in the meeting. The Constituents had
regularly been kept apprised of the tripping events incident to their respective systems vide
various SRPC mails. However, no replies have been received from APGENCO, APTRANSCO,
TSGENCO, TSTRANSCO during the period 30.11.2015 to 26.01.2016.
The Constituents have been requested to kindly furnish the remedial measures/ action taken in
time so as to forward the same to Central Electricity Authority. The updated list of the same as
on 11.02.2016 is enclosed at Annexure-V.
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 the monthly certificate for healthiness of batteries, installed at 220 KV
and above voltage level Substations (for power supply to Relays, RTUs and PLCC equipment) and
furnish the same to CEA/ MoP.
With reference to above, the Constituents have been requested to submit the certificate on
healthiness of batteries on monthly basis (i.e. status for a month may be sent by the 7th day of
the following month) to SRPC.
The sought status for the months of November & December, 2015 has not been received from
the following SR-Constituents:
November, 2015: APGENCO (Thermal), TSGENCO (Thermal), KPTCL, PED, NPCIL
MAPS, NTPL, CEPL, SEL.
December, 2015: APTRANSCO, TSGENCO (Thermal), TANGEDCO, PED, TPCIL, NTPL
NTPC-Ramagundam, CEPL, SEL.
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 3
7. CEPL Agenda Item: Special Protection Scheme in NTPL-CEPL-Tuticorin PS Complex
CEPL vide their letter dated 07.01.2016 (Annexure-VI) proposed an SPS in Tuticorin PS -CEPLNTPL Complex for running both the Units of CEPL till June, 2016 by which time both CEPL and
PGCIL would complete their respective lines.
The issue was discussed in the meeting, when SRLDC pointed out that in the meeting held at
CEA, New Delhi on 11.12.2015 regarding "2x600 MW Mutiara Thermal Power Project Permission for Synchronization and declaration of COD of Unit _2", CEPL had assured that the
work relating to their dedicated transmission lines would be completed by April-May, 2016. It
was emphasised that in case of any revisions in the completion of their dedicated transmission
system, CEPL shall also keep SRLDC & SRPC informed to plan accordingly. As regards the SPS
proposed by CEPL, SRLDC stated that it could not be agreed to in its present form because of
the following reasons:
 The generation from the second Unit of CEPL , for accommodating which the present SPS
is proposed, has not been tied up;
 In the SPS proposed, the details of the loads to be shed to balance LGBR in the event of
tripping of one of the Units has not been spelt out;
 In the event of non-operation of SPS, there is a real chance that end-equipment at NTPL
switchyard may get damaged due to the limitation imposed by its bus-bar rating of 1350
MW, 2000 A.
TANTRANSCO also opined that since the loads are yet to be identified for the proposed SPS,
the issue may be discussed in detail in the forthcoming OCC meeting.
It was therefore agreed to take up the issue in the next OCC meeting.
8. Network configuration changes
As per the information furnished by SR-Constituents to the OCC forum in their 114th meeting
(held on 08.12.2015; Minutes circulated on 31.12.2015) and 115th meeting (held on
08.01.2016; Minutes circulated on 29.01.2016), the following network configuration changes
(additions/ deletions/ modifications of transmission elements) took place in the southern grid
during the period November-December, 2015.
7.5 WM Installed Capacity was added in Tamil Nadu in Private Sector during the month of
November 2015.
Unit – VI at Nagjhari Power House up rated from 135MW to 150MW.
220kV D/C Line from Pallantla substation to 220/11kV LIS substation at Pattiseema in East
Godavari district of 60 CkM was commissioned (feeder I on 06.11.2015 & feeder II on
07.11.2015) by APTRANSCO.
220kV Appayyadorapalem - Bobbili SC line in Vizianagaram District of 84 CkM was
commissioned on 12.11.2015 by APTRANSCO.
220/11 kV LIS substation at Pattiseema in East Godavari district of 60 MVA Capacity was
commissioned on 08.11.2015 by APTRANSCO.
Bobbili Growth Center 220kV SS in Vizianagaram District of 100 MVA Capacity was
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 4
commissioned on 13.11.2015 by APTRANSCO.
2nd PTR at 220kV SS Rachagunneri in Chittoor district of 100 MVA Capacity (2nd PTR) was
commissioned on 25.112015 by APTRANSCO.
220kV SS Kalyandurg in Ananthapur District(220 kV, 2x100 MVA) was Augumented to a
capacity of 3x100 MVA and commissioned on 02.11.2015 by APTRANSCO.
220kV SS Kamavarapukota in East Godavari District (220 kV, 2x100 MVA) was augumented
to 3x100 MVA capacity of and was commissioned on 21.11.2015 by APTRANSCO.
220 kV D/C Line from Pallantla substation to 220/11kV LIS substation at Pattiseema in East
Godavari district of 60 CkM was commissioned. (feeder I on 06.11.2015 & feeder II on
07.11.2015) by APTRANSCO.
220 kV LILO to 220 kV existing Gajwel-Kamareddy line to 220/6.6 kV water pumping SS to
Kondapaka of 19.5 CkM was commissioned on 10.11.2015 by TSTRANSCO.
220/6./6 kV Kondapaka water pumping substation in Medak District of 63 MVA Capacity
was commissioned on 10.11.2015 by TSTRANSCO.
220/132/33 kV SS Waddekothapally in Warangal District (3x100 MVA) capacity was
augmented to a Capacity of (1x160 +2x100) MVA and was commissioned on 24.11.2015
by TSTRANSCO.
220/132/33 kV Boothpur SS in Mahaboobnagar District (2x100+1x160+1x16) was
augmented to a capacity (2x100+1x160+1x16+1x50) and was commissioned on
18.11.2015 by TSTRANSCO.
220/132/33 kV SS Narketpally in Nalgonda District of (1x31.5+1x15) MVA capacity was
augmented to a capacity of (1x50+2x31.5) MVA and was commissioned on 13.11.2015 by
TSTRANSCO.
220/132/33 kV SS Kalwakurthy in Mahaboobnagar Dist.of (1x50+2x31.5)MVA Capacity
was augmented to a Capacity of 2x50+1x31.5 MVA and was Commissioned on 16.112015
by TSTRANSCO.
765kV Kudgi – Kolhapur I charged at 400kV level on 14th November 2015 by PGCIL
400kV Narendra – Kudigi I charged on 17th November 2015 by PGCIL
400kV Gooty – Madhugiri (Tumkur) D/C charged on 29th November 2015 by PGCIL
400kV Kudgi –Kudgi NTPC charged on 17th November 2015 by PGCIL
400/220kV ICT- 3 & 63 MVAR Bus Reactor at Raichur was charged for first time on 24th
November 2015 by KPTCL.
63 MVAR Bus Reactor charged at 400kV Talaguppa S/S on 26th November 2015 by KPTCL..
125 MVAR Bus Reactor charged at NCC for first time on 04th December 2015
PGCIL vide letter dated 09.11.2015 had informed that consequent to the
successful completion of Trial Operation, the following assets under Transmission System
Associated with “Contingency Plan for evacuation of Power from IL & FS (2x600) MW have
been put under Commercial Operation with effect from 00:00 hrs of November, 2015 in
terms of Clause 4 CERC (Terms and conditions of Tariff) Regulations, 2014.
 Strengthening of Neyveli TS II – TS- I expansion Link with higher Capacity
Conductor).
PGCIL vide letter dated 01.12.2015 had informed that consequent to successful
completion of Trial Operation, the following assets under “Transmission System
associated with System Strengthening –XIII in Southern Regional Grid” have been put
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 5
under Commercial Operation w.e.f 00:00 Hrs of 1st December 2015 in terms of clause 4 of
CERC (Terms & Conditions of Tariff) Regulations 2014 and 27th SRPC minutes of meeting
point No 3.2.3.
 Gooty – Madhugiri 400KV D/C line Extension of 400/220KV substation at Gooty –
Madhugiri 400KV D/C Line.
 400/200KV Substation at Madhugiri (Tumkur) with 2x500MVA Transformers and
1x63MVAR Bus Reactor along with associated bay & Equipments for Gooty –
Madhugiri 400KV D/C Line.
PGCIL SR II vide letter dated 11.12.2015 had informed that consequent to the successful
completion of Trial Operation the following assets under Transmission System associated
with “System Strengthening-XVII in Southern Grid” have been put under Commercial
Operation with effect from 00:00 hrs of 11th December 2015 in terms of Clause 4 of
CERC(Terms and Conditions of Tariff) Regulations, 2014.
 Second Circuit of Narendra (New Kudgi) – Kolhapur(New) 765 D/C Transmission
line(initially charged at 400 KV) along with bays & equipments at Narendra(New
Kudgi) substation and Kolhapur(New) substation.
 Transmission charges for the above assets are payable with effect from 11th
December, 2015.
PGCIL SR II vide letter dated 11.12.2015 had informed that consequent to the successful
completion of Trial Operation the following assets under “Sub Station Extension works
associated with transmission system required for evacuation of power from Kudgi
TPS(3x800 MW in Phase I) of NTPC Limited in Southern Regional Grid” have been put
under Commercial Operation with effect from 00:00 hrs of 11th December 2015 in terms
of Clause 4 of CERC(Terms and Conditions of Tariff) Regulations, 2014.
 4 Nos. 400 kV Line bays at Narendra(New, Kudgi) for Kudgi TPS-Narendra (New,
Kudgi) 400 kV 2xD/C Quad Lines.
 Transmission charges for the above assets are payable with effect from 11th
December, 2015.
PGCIL SR II vide letter dated 11.12.2015 had informed that consequent to the successful
completion of Trial Operation the following assets under Transmission System associated
with “System Sregthening-XVII in Southern Grid” have been put under Commercial
Operation with effect from 00:00 hrs of 11th December 2015 in terms of Clause 4 of
CERC(Terms and Conditions of Tariff) Regulations, 2014.
 Narendra(New Kudgi) – Narendra(Existing) 400 kV D/C Quad Transmission line
along with associated bays & equipments at Narendra(New Kudgi) substation and
Narendra (Existing) substation.
 Transmission charges for the above assets are payable with effect from 11th
December, 2015.
PGCIL SR II vide letter dated 15.12.2015 had informed that consequent to the successful
completion of Trial Operation the following assets under Transmission System associated
with “System Sregthening-XXII in Southern Grid” have been put under Commercial
Operation with effect from 00:00 hrs of 15th December 2015 in terms of Clause 4 of
CERC(Terms and Conditions of Tariff) Regulations, 2014 and 27 SRPC Minutes of Meeting
point No. 3.7.
 Kunool(New) – Raichr 765 kV S/C line.
 Extension of 765/400 kV S/S at Kurnool(New): [1 No. 765 kV line bay for
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 6
Kurnool(New) – Raichur 765 kV S/C line]
 Extension of 765/400 kV S/S at Raichur: [1 No. 765 kV line bay for Kurnool(New) –
Raichur 765 kV S/C line]
765 kV Raichur – Kurnool Line I was charged on 13th December 2015 by PGCIL.
400 kV Nagarjunasagar – Khammam II & III were charged on 31st December 2015 by
PGCIL.
PGCIL vide letter dated 04.01.2016 had informed that consequent to the successful
completion of Trial Operation, the following assets under “Substation works associated
with System Strengthening in Southern Region for import of Power from Eastern Region”
have been put under Commercial Operation with effect from 00:00 hrs of 4th January
2016 in terms of Clause 4 CERC (Terms and conditions of Tariff) Regulations, 2014.
 400 kV Bays each at Khammam (Existing) and Nagarjunasagar for terminating
Khammam - Nagarjun Sagar 400 kV D/C line has been implemented under Tariff
Based Competitive Bidding.
PGCIL vide letter dated 03.01.2016 had informed that on successful completion of
seventy two (72) hours of connection with the interconnection facilities the following
element is put under Commercial operation w.e.f. 1600 Hrs on 03.01.2016 in terms of
article 6.2.1, Transmission service Agreement (TSA) dated 14.05.2013 and accordingly
POWERGRID Vizag Transmission Limited is entitled for all benefits envisaged in the
aforesaid TSA.
 400 kV Khammam(existing) – Nagarjunasagar Transmission D/C line under
Transmission system for System Strengthening in Southern Region for import of
power from Eastern Region.
KPTCL vide their mail dated 23.01.2016 informed that the following transmission
elements had been commissioned in December, 2015.
 220 kV Yelahanka DG Plant station commissioned on 28.12.2015 by extending
power supply from existing 220kV Nelamangala - Hoody line
 220 kV Gadag-Bagalakot D/C line charged on 28.12.2015
9. Instances of SPS Operations
Based on the information furnished by SRLDC, it is informed that the following instances of SPS
operations took place in SR during the period 30.11.2015 – 26.01.2016.
Sl
Date
No
1 21-Jan-16
Time
(hrs)
14:23
2
21-Jan-16
14:34
(twice)
3
21-Jan-16
14:36,
14:37,
14:38
Reason
Raichur-Sholapur SPS operated
while preparing for emergency LC
of Talcher-Kolar pole-2
Raichur-Sholapur SPS operated
while preparing for emergency LC
of Talcher-Kolar pole-2
Raichur-Sholapur SPS operated
while preparing for emergency LC
of Talcher-Kolar pole-2
Minutes of the 50th PCSC Meeting held on 27-01-2016
Load relief obtained (MW)
AP KPTCL KSEB TNEB Total
75
79
154
150
60
210
60
60
Page 7
4
21-Jan-16
14:47
(twice),
14:56
Raichur-Sholapur SPS operated
while preparing for emergency LC
of Talcher-Kolar pole-2
150
150
10. Compliance of Hon’ble CERC Orders
10.1
Petition No. 146/MP/2013 with I.A. 36/2013: Order dated 20.02.2014
 Compliance of Regulations 5.2 I of the Grid Code: Issue regarding non-furnishing of
FIR / Trip Analysis Report, EL, DR, etc. was also highlighted. It is pointed out that
the above reports are to be submitted / uploaded on SRLDC web application within
24 hours as mandated under IEGC / CEA Regulations.

Implementation of Phase-I and Phase-II of Protection Audit Recommendations: All
the constituents are requested to submit the updated status of the compliance
(those who have not completed recommendations mentioned in the Phase I and
Phase II) to SRPC Secretariat at the earliest.

Compliance of Regulations 5.2 (e) & 5.2 (l) of the Grid Code and Regulation 3(1)(e)
of CEA Grid Standards: The constituents are requested to strictly comply with these
provisions by ensuring standard protections systems having the reliability,
selectivity, speed and sensitivity to isolate the faulty equipment and protect all
components from any type of faults, within the specified fault clearance time and
providing protection coordination

Ensuring proper maintenance of transmission lines and adopting best O&M
practices: The constituents are requested to conduct line patrolling regularly 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).
(http://www.srpc.kar.nic.in/website/2014/operation/patrolling.pdf).
10.2
Petition No. 167/Suo- Motu/2012: Order dated 22.02.2014
 The Constituents are requested to follow approved protection philosophy
 ISTS licensees are requested to submit details of updated distance protection relay
setting of all inter-regional lines to POSOCO & RPCs.
 All SLDCs are requested to install/activate sound recording system in their control
rooms within three months from the date of issue of this order.
 The Constituents are requested to submit the progress of implementation to SRPC
and SRLDC as specified in the Hon’ble CERC Order.
10.3 Petition No. 263/MP/2012: Order dated 19.12.2013
 Constituents are requested to implement the quantum of relief by AUFR and df/dt
relays by identifying additional feeders and keep them functional within one
month of issuing this order.
 SLDCs are also requested to map these relays on their respective SCADA system
within three months of issuance of this order.
 The Constituents are requested to submit the progress of implementation to SRPC
and SRLDC as specified in the Hon’ble CERC Order.
10.4 APTRANSCO’s Petition No.95/MP/2015: Date of hearing 09-04-2015
It was noted in the Analysis and Decision part of the Order that:
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 8
“8. Noting the submissions of the petitioner, SRPC and SRLDC and activities initiated by
the petitioner for procurement of materials required for implementation of the remarks
of protecting audit, we allow time to the petitioner till 31.12.2015 for completion of our
directions in Order dated 19.12.2013 in Petition No. 146/MP/2013.”
“9. SRPC is directed to monitor the status of completion of works relating to protection
audit remarks in respect of 7 nos 400 kV sub-stations and 11 nos 220 kV sub-stations of
APTRANSCO, protection audit remarks in Protection Coordination Sub-Committee
(PCSC) meetings and coordinate the periodic protection audit to be carried out in
Southern Region after deliberation in SRPC and submit bi-monthly report to the
Commission.”
10.5
TSTRANSCO’s Petition No.83/MP/2015: Order dated 14-05-2015
It was noted in the Order that:
“12. Noting the submission of the petitioner, SRLDC and SRPC and considering the
actions already initiated by the petitioner for implementation of works relating to
protection audit, we allow time till 31.10.2015 and 31.8.2016 for implementation of
Phase-I and Phase -II works respectively. The petitioner is directed to submit affidavit
confirming the completion of Phase I of protection audit remarks by 31.10.2015 and
Phase-II of protection audit remarks by 31.8.2016.
13. SRPC is directed to monitor the status of completion of remarks in these substations
vis-à-vis protection audit remarks in Protection Coordination Sub Committee (PCSC)
meetings. SRPC is further directed to coordinate the periodic protection audit to be
carried out in Southern Region after deliberation in SRPC.”
10.6
Order in Petition No. 86/MP/2014 and 374/MP/2014: Order dated 18-08-2015
The time-lines given to the various SR-Constituents for completion of Phase-I and Phase-II
activities of Protection Audit Recommendations vide above Order are given below:
(A) KSEBL:
18. Noting the submission of KSEBL, SRLDC and SRPC and considering the actions
already initiated by KSEBL for implementation of remarks of protection audit, we
allow time till 31.12.2015 and 31.3.2016 for implementation of Phase-II works
and R&M works at Idduki HEP respectively.
(B) TANTRANSCO:
21. After considering the submissions of TANTRANSCO, SRLDC and SRPC, it is noted that
TANTRANSCO`s request for time till 31.5.2015 for implementation of Phase–I activities
of providing numerical relays for feeder protection and Auto transformer protection is
already over. We allow time till 30.6.2016 for other Phase-I activities such as provision
of line VT, 5 core CT, Time synchronizing with GPS, Disturbance recorder & event logger
and Phase-II activities. According to SRLDC, total implementation period is 15 to 16
months for items which involve major procurement, design changes with major site
modification/civil activities. Accordingly, we allow 16 months time i.e up to 30.11.2016,
for Renovation and Modernization of Singarpet, Singaperumalkoil, Salem and
Tondiarpet 230 kV sub-stations from the issue of the order.
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 9
(C) NLC:
22. NLC has sought time upto 31.12.2014 and 31.3.2015 for completion of Phase-I work of
Numerical Relay Retrofitting and for Phase-II works of providing second battery bank of
PLCC respectively. It is noted that the completion dates for Phase-I and Phase-II of
protection audit remarks as requested by NLC are already over. Therefore, no direction
is required in this regard. However, we direct NLC to file a confirmation report
regarding completion of protection audit works for Phase-I and Phase-II.
(D) KPTCL:
23. …
…
Considering the submission of KPTCL and SRLDC, we allow time to KPTCL time till
15.01.2016 for completion of Phase-I and Phase-II of protection audit remarks. No
further extension shall be granted in this regard.
(E) KPCL:
24. …
…
Considering the submission of KPCL and SRLDC, we allow time to KPCL till 31.10.2015
and 31.12.2015 for completion of Phase-I for Phase-II of protection audit remarks
respectively. No further extension shall be granted in this regard.
26. We direct SRPC to (a) submit status of protection audit remarks in respect of
APGENCO, NTPC (SR), Talcher, Puducherry, PGCIL (SRTS I & II), MAPS and TANGEDCO,
(b) monitor the status of completion of remarks of protection audit in respect of all
constituents of Southern Region in Protection Coordination Sub-Committee (PCSC)
meetings, and (c) to coordinate periodic protection audit to be carried out in Southern
Region after deliberation in SRPC. All the constituents of Southern Region are directed
to file their status with SRPC on regular basis to facilitate proper monitoring in PCSC
meetings. SRPC is directed to submit bi-annually status report to the Commission
confirming the completion of Phase-I, Phase-II and R&M works of protection audit
remarks of the constituents of Southern Region.
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/ PCSC45/ 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
Minutes of the 50th PCSC Meeting held on 27-01-2016
Page 10
Generating Transformer
SSN_GT#_FT
Generating Unit
SSN_Unit#_FT
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 followed at all stations in their control area so that tripping
analysis can be done systematically.
12. Date & Venue of the next Meeting
It is informed that the 51th PCSC meeting will be held on 25.02.2015 (Thursday) at
10:30 hrs in the Conference Hall of SRPC, Bengaluru.
13. Vote of Thanks
Member Secretary, SRPC thanked the members and other participants for their active
contribution in the deliberations.
Sh. J. Mammen, GM (Commercial), NTPC thanked all the Members for their cooperation.
*****
Minutes of the 50th PCSC Meeting held on 27-01-2016
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Minutes of the 50th PCSC Meeting held on 27-01-2016
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Annexure- I
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Annexure- I
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Annexure- I
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Annexure- I
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Annexure- I
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Annexure- I
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Annexure-II
DETAILED SCOPE OF WORK
Bidder should supply Protection Analysis Software Package with following requirements but not
limited to the following modules for the supply of Software and Database building activities:-
The vendor should develop and maintain a hardware setup and software package capable of
meeting the following objectives; but not limited to:
 Classified database of all bay equipment and the protection system details of all
bays 220 kV/ 230 kV and above, for Southern Regional power System.
 A user friendly interface for browsing and editing the contents of the database
 Tool for simulating the performance/ behavior of the protection system under all
possible normal and abnormal operating conditions of the power system,
including effect of changing one or more parameter setting of the relays.
 Diagnostics for verifying proper coordination among various protective relays
 Generation of useful reports
E.1 Database building activities:
 One time power system network model building for the Load-flow, Short circuit
and dynamic simulations of entire Southern region with Indian national grid
transmission network model.
 Data collected from respective substations to be validated before populating the
same in the database.
 Complete modeling of SR transmission network for 220 kV/ 230 kV and above
including HVDC systems connected with SR, with relevant system parameters
collecting from the field like transmission lines, generators, transformers,
reactors, substation layouts, and associated protective relays in the substations.
The model should include CT, PT, Isolator, Breaker and other bay equipment’s
ratings along with rating of the BUS and the type of conductor used for the BUS.
The modeling should be done as per bus-breaker philosophy instead if node
oriented model.
SRPC, Bengaluru
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Annexure-II
 Building of network Database and populations of relay data for all existing
substations of 220 kV / 230 kV and above voltage level, of Southern region
including Generating station switchyards as well as the Generators.
 Prepared network should be ready for base case load flow analysis and the same
has to be verified with field engineers of SR constituents. Both MW and MVAR
flow should be computed and Voltage Level at different Buses should be
ascertained along with suggestive conditions to reduce or enhance Bus voltage.
 Short circuit, transient stability and contingency analysis have to be simulated and
the results have to be demonstrated to the SR constituents for approval. There
should be features to study low frequency oscillations, 3rd zone tripping, PSS
tuning support and Voltage collapse prediction feature.
 Transient stability and grid disturbance simulation studies for the southern region
database and performing the com-trade file analysis.
 Over current and distance relay coordination settings have to be calculated and
coordination curves should match the existing protection schemes of the
substations. Some critical contingencies have to be discussed with SR constituents
and the same has to be simulated and results to be demonstrated.
 Computation of critical clearing time for the most of the voltage level and critical
stations.
 Review of the unit protection like Generators, GT’S , Unit transformers, Station
transformers), ICTs, Main power transformers, Reactors, Dynamic and Static
Compensators, bus-bars and other differential protection relays.
 Following are estimated details of the existing sub-station in the SRPC region and
same should be modeled in the software with all details. However, actual number
may vary within close limits and has to be considered by the bidder in his
proposal.
No. of 765 kV No. of 400 kV No. of 220/230 kV
sub-station
sub-station
sub-station
6
111
478
 Capacity building and training at SRPC office and each state.
SRPC, Bengaluru
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E.2 Protection Setting Calculation Tool
This module should compute optimum relay settings for improved performance for all type of
commercially available distance/over current/EF/differential/line/transformer protection relays.
Relay co-ordination shall be conducted for relays of all make and with user defined
characteristics for overcurrent and distance relays in line with the protection philosophy,
followed by SRPC.
The package will involve fault studies followed by relay setting, checking and co-ordination
studies to ensure that the wide variety of protective relays function correctly with proper
discrimination to provide the required reliable, sensitive and selective isolation of faulty power
system equipment.
i.
Relay co-ordination for radial and interconnected power system networks for over
current relays.
ii.
Primary/back-up relay pairs generation.
iii.
Fault calculation will be a part of relay co-ordination program.
iv.
Transparent Fault calculation results.
v.
Built with standard relays library data for different manufacturers, including but
not restricted to the following protection features:- (i) Line protection: Distance,
over current, earth fault, over voltage (ii)Line Differential protection (iii)
Transformer Differential Protection (iv) Transformer Over fluxing Protection (v)
Transformer Thermal Overload Protection (vi) Transformer Low Impedance
Restricted Earth Fault Protection and High Impedance Restricted Earth Fault
Protection (vii) Generator Overall, Generator Transformer and Unit Differential
Protection (viii) Generator Inter – Turn Differential Protection (ix) Generator
Transformer Low Impedance and High Impedance Restricted Earth Fault
Protection (x) Generator Stator Earth Fault Protection ( Both 95% and 100%
protection) (xi) Generator Rotor Earth Fault Protection (xii) Generator Loss of
Excitation Protection(Field Failure) ( with and without Under voltage) (xiii)
Generator Forward Power and Reverse Power Protection (xiv) Generator BackUp Impedance protection (xv) Generator Inadvertent energisation (xvi) Generator
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Negative Sequence Protection, (xvii) Generator Pole Slip Protection (xviii)
Generator Thermal Overload Protection (xix) Feeders Directional and NonDirectional Over current and Earth Fault Protection with standard and
nonstandard curves (User defined curves).
vi.
Plotting Log- Log grid and graphs.
vii.
Option to check existing relay settings as per the Field and vice versa.
viii.
Unit protection settings computation for Generators/ line/transformer /reactor/
busbar etc.
ix.
Computation of Out of Step Tripping Protection Settings.
x.
There must be display of sequential operation of relays with respect to tripping
time.
xi.
There must be switching status for all relays elements/bay equipment available on
the screen.
xii.
There must be association of relays to power system elements.
xiii.
Co-ordination check can be conducted for relays of all make and with user
defined characteristics for over current and distance relays.
xiv.
Disturbance analysis should be done with single click on mapping of disturbances
files with corresponding relay.
xv.
It must have standard power system components and relay symbols.
xvi.
There must be Phase as well as Earth relay co-ordination. Co-ordination between
Normal, Non - Directional Earth Fault and Common Earth Fault should be
provided.
xvii.
There must be instantaneous setting for relays.
xviii.
There must be automatic computation of zone setting for different standard make
Relays with proper characteristics selection such as ABB, Areva, Siemens, SEL,
GE, ER etc. for both in terms of Primary and Secondary impedances (considering
the used CTR & PTR) .
xix.
There must be a feature of viewing existing and newly computed relay settings
simultaneously.
xx.
There must be Pre-loaded standard relay curves.
xxi.
Directional and non-directional feature for relays should be incorporated.
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xxii.
There must be overload factor, unbalance factor and discrimination time (user
defined/selectable) for each relay.
xxiii.
There must be inbuilt discrimination time calculator.
xxiv.
It should be possible to model the back-up protection settings of generating units
/ GTs connected to the grid at 230 kV/ 220 kV and above level, so that
coordination between power plant and transmission system protections may also
be tested / verified.
E.3 Protection Database Management System:
Web based Enterprise license of Database tool and populating of all the relay templates and
also relay field data into the software and customizing the approval procedures Protection data
management system is an asset management tool for maintaining information on relay attributes
and settings. The software should be capable of maintaining the entire data belonging to all
relays. Once data fits in the software it should be capable of porting the data to any third party
application for analysis and also various reports generated. The data would be accessed over web
for use in protection calculation tool.
The Protection database management system should have the following capabilities:
1. Web based
2. Role based access control
3. Flexible customization of user roles, grants, actions from Master control panel
4. User Access Monitor
5. Relay Template management
6. Create\Edit\Delete relay templates
7. Viewing relay template
8. Locking and Unlocking templates
9. Copy & Edit templates from the existing template
10. Import and Export templates
11. Relay Data management
12. Create\Edit\Delete relay data
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13. Viewing relay data
14. Locking and Unlocking relay data
15. Copy & Edit relay data from the existing data
16. Import and Export relay data
17. Configuration management: Should have option to configure user defined levels for
generating relay indexing
18. Work flow Management
19. Relay template life cycle management
20. Relay data life cycle management
21. Reports:
a. Should be possible to generate reports as per user requirement
b. User can export generated report to the standard format like .xls, pdf. .doc etc.
c. History Logger : All user activities including user operations, data management,
template management, configuration management and workflow should be logged
to track the user activities over a period of time
d. Import and Export : There should be an option to import template and data from
any third party application in standard formats like xml and xls format
e. There should be option to integrate any third party application to share data
between protection database management software and calculation engine\tool
and vice versa.
f. Should be able to draw the relay characteristic curve from the setting data
g. Provision to attach documents to relay template and relay data should be
available.
h. There should be option to accept setting data as per the audit and verify\compare
the field setting with protection database setting and generate error report
i. Provision to store and retrieve audit reports
j. Provision to store and retrieve relay tripping incidence report
k. There should be facility to store and retrieve setting guidelines as per various
committees.
l. Automatic Reconciliation Tool would generate automatic reconciliation requests
for relay settings in the database and in the relay hardware.
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m. Up-to-date application guides and user manuals of all relays should be part of the
relay library
n. Web based Checklist for protection Audit.
SRPC, Bengaluru
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Grid Occurrences
1. Details of Grid Disturbances:
1
Complete outage of 220kV Somanahalli substation of KPTCL
(i)
Date and Time of Event
27-11-2015 at 18:47 hrs
(ii)
Location
220kV Somanahalli Substation
(iii)
Reported Disturbance /
Fault
Bus bar protection got operated due to wrong bus bar zone
selection resulting in tripping of both the 220kV bus at 220kV
Somanahalli substation.
(iv)
Load Loss
650 MW
(v)
Category
GD-1
SLD:
 The SLD of 220 kV Somanahalli SS as provided by KTPCL is attached at the end.
KPTCL:
 Line clear (LC) was availed at 220kV Somanahalli SS on 27.11.15 at 10.30 hrs to facilitate dismantling of strung
bus and replacement of the same by rigid bus on South bus [Partial before sectionalizing breaker from control
room] under the R&M works. Before availing LC, various 220kV bays connected to different buses are as
follows:1. North Bus:- Bidadi -1, Bidadi -2,100MVA Tr-1,100MVA Tr-3 and Malur-2.
2. South Bus:- ICT-1,ICT-2,HSR Layout ,ITPL, Yerandanahalli, NRS, Subramanyapura, T.K.Halli.
*** Malur-1 was kept out of service.
 The sequence of operations carried out for issue of LC on South bus(partial):a. Bidadi 1&2,Tr-1,Tr-2 Malur-2 were hand tripped.
b. Bus coupler breaker was closed.
c. ICT-1,ICT-2,ITPL,Yerandanahalli,Subramanyapura were shifted from south bus to North bus (Online
transfer)
d. Bus Coupler breaker operated.
e. ICT-1 tripped.
f. Both sectionalizing breaker tripped.
g. Bidadi-1 shifted to South Bus and HSR layout was fed from Bidadi-1 Line.
 During these operations, the Bus bar protection was kept out of service. Upon completion of work during
normalization, the details of various bays connected to buses are as follows:1. South Bus:- Bidadi-1 and HSR Layout.
2. North Bus:- ICT-1,ICT-2,100MVATr-1,100MVATr-3,T.K.Halli, NRS, Subramanyapura, Yerandanahalli, ITPL,
Malur-2.
3. Bidadi-2 kept opened.
4. 150MVA Tr-2 kept opened as the same is faulty.
 In bus bar protection scheme, the switches were provided in the bus bar panel to replicate the isolator
positions 89A and 89B to decide the zone selections. After selection of the switch according to 220kV Bays
rearrangement, the bus bar differential relay was put into service. But immediately differential relay acted with
indication as Zone A and B. and all bays tripped. Therefore on temporary basis the relay was kept out of service
and bays normalized.
 It was explained that due to the problem in the auxiliary contacts of the bus-isolator switches, the isolator
replica switches in the bus bar panel were being operated manually. In the instant case, due to manual error in
the selection of these replica switches, ICT-1 & ICT-2 currents got added up, and resulted in operation of BBP
for both Zones – A & B. After detailed investigation by RT staff on 28.11.2015, bus bar protection was restored
at 220kV SS Somanahalli.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 1/32
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Annexure- III


It was informed that as existing BBP is of static type, DR and EL were not triggered.
Remedial action:
 The suspected faulty isolator switch auxiliary contacts had been replaced.
 Strict instructions have been issued to the maintenance staff to exercise due care while effecting bay/ bus
change-over operations.
 All bus isolator switches have also been proposed to be replaced as part of the ongoing R&M works.
KSEB:
 Separate CT-cores may be used for CHECK zone and MAIN zone. If that is not possible, an external CT-shorting
switch may be provided to discriminate between CHECK and MAIN zones.
2
Complete outage of TPCIL power station
(i)
Date and Time of Event
30-12-2015 at 06:02hrs
(ii)
Location
400kV TPCIL Generating Station
(iii)
Reported Disturbance /
Fault
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)-ECC line
(iv)
Generation Loss
1270 MW
(v)
Category
GD-1
SLD:
 SLD of TPCIL station is attached at the end.
400 kV TPCIL-NPS line (Line-2):
TPCIL end:
 As per FIR/ DR/ EL, the line tripped at 6:02:40.570 hrs. on R-Y fault due to operation of DPR, Z1 operation (at
4.1 km from TPCIL end). [In EL, Station name in the signature was mentioned as Krishnapatnam, which may
be corrected]
NPS end:
 As per FIR/ DR/TR, the line tripped at 6:02:40.570 hrs. on R-Y fault due to operation of DPR, Z2 operation
 It was observed from DR that the line tripped at NPS end simultaneously with TPCIL end without waiting for
any Carrier or time-delay.
 Line EL not furnished. Furnished EL was Station’s stand-alone EL. In this, events relating to this line tripping
were not recorded. Further, EL was not configured for showing events at msec. level.
400 kV NCC-NPS line (Line-1):
NCC end:
 No Files uploaded. It was informed that line did not trip at NCC end.
NPS end:
 As per FIR/ DR/TR, the line tripped at 6:02:40.570 hrs. on R-Y fault due to operation of DPR, Z2 operation.
 From DR, it was seen that this trip had happened almost at the same time at which TPCIL-NPS line tripped.
 Line EL not furnished. Furnished EL was Station’s stand-alone EL. In this, events relating to this line tripping
were not recorded. Further, EL was not configured for showing events at msec. level.
PGCIL (SR-I):
 In the Main-2 (REL-670) relay provided at NPS end on NPS-TPCIL line, the zone-2 timing was wrongly kept as
zero sec, due to which the line tripped at NPS end instantaneously.
 During this event, the REL-670 (ABB-make) relay at NPS end on NPS – NCC line mal-operated to trip the line.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 2/32
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Annexure- III

Remedial action:
 Zone-2 time in all relays at NPS end had been properly set.
 The mal-operation of relay at NPS end on NPS – NCC line has been taken up with its OEM (ABB).
TPCIL Unit-1:
 As per FIR, Unit-1 tripped at 6:02:41 hrs on turbine over-speed protection.
 No DR/EL furnished.
TPCIL Unit-2:
 As per FIR, Unit-2 tripped at 6:02:41 hrs on Generator protection.
 No DR/EL furnished.
SRPC:
 It was noted that the tripping was also discussed in the 115th OCC held on 08-01-2016, when TPCIL had made a
plea to exempt them from paying any UI charges/ Penalty under the DSM mechanism as the cause of their
Units’ tripping was beyond their control.
 In the recent past, mal-operation or over-reaching of relays at NPS end has been observed for faults on the
adjacent lines/ lines connected at remote end stations. The Nellore PS has been basically designed to evacuate
power from the generating stations in the Nellore complex, like MEPL (2x150 MW), SEL (4x150 MW), TPCIL
(2x600 MW), NCC (2x660 MW), which are connected to it by short transmission lines of length varying from 6
km to 33km.
Nellore Pooling Station (NPS)
Gooty
289 km
26.88 km
MEPL
6.35 km
NELLORE
(PGCIL)
26.88 km
SEPL
33 km
TPCIL
32.5 km
NCC

From the above, it can be seen that any unwarranted tripping of these short transmission lines such as that
occurred in the instant case will have huge impact on the ATC and attendant commercial transactions. Thus,
considering the criticality of Nellore PS, it is all the more wise/necessary to ensure that protection systems in
place do not mal-operate. Since all these lines (except Gooty feeder) are of length less than 35 km and optical
fibre has already been laid between these stations, it is a fit case for replacing the conventional distance
protection by the more accurate line differential protection on all the 400 kV lines (of length less than 35 km)
emanating from Nellore PS.
 The issue was discussed in the meeting, and after ascertaining the views of PGCIL and the generators, PCSC
forum has agreed in-principle to providing line-differential protection on all 400 kV lines (of length less than
35 km) emanating from Nellore PS.
 On this, TPCIL requested that in order avoid to problems arising out of incompatibility of relay makes, it is
better that PGCIL purchase necessary equipment for both ends of the lines, and supply to them on payment
basis. To this, PGCIL assured that it would be looked into favorably.
SRLDC:
 To ensure healthiness of carrier communication, PLCC end-to-end testing may be carried out by NPS in
coordination with TPCIL.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 3/32
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Annexure- III

Further, taking note of the fact that this grid disturbance involving TPCIL Units had primarily occurred because
of mal-operation of the relays at NPS end, it is clarified that this tripping event is a Grid Disturbance as per IEGC
Regulation 6.5.17.
Recommendations:
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.
PGCIL (SR-I) to appropriately configure Station Event Logger at NPS to record events at msec interval.
PGCIL (SR-I) to carry out PLCC end-to-end testing in coordination with TPCIL for 400 kV NPS –TPCIL line.
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.
Complete outage of 230kV Mywadi station of TANTRANSCO
3
(i)
Date and Time of Event
21-12-2015 at 6:28 hrs
(ii)
Location
230 kV Mywadi Station
(iii)
Reported Disturbance /
Fault
Busbar protection got operated for a fault in 230kV MywadiAnaikadavu line
(iv)
Load Loss
(v)
Category
GD-1
SLD:
 The SLD of 230 kV Myvadi SS as provided by TANTRANSCO is attached at the end.
230 kV Myvadi – Anaikadavu line:
Myvadi (TANTRANSCO) end:
 From DR, the line tripped at 5:50:06.012 hrs on B-E (RYB) fault due to DPR, Z1 operation. However, within 30
msec, the other two phases also seemed to have got opened. But, continuous dip in voltages was observed
only in Y and B phases of 230 kV Mywadi-Anaikadavu line. [So it appears that the line did not try for autoreclosure (for B-E fault) at any of the ends].
 In EL, the Events before 5:50:06.012 hrs were not shown. Hence the cause of the line trip was not clear.
Anaikadavu end:
 From DR, the line tripped at 6:27:03.475 hrs on B-E fault due to AR/ DPR, Z1 operation. But while the fault
(and voltage dip in phase-B voltage) seemed to have got cleared itself within 100 msec, A/R operation
sustained up to 650 msec. So, operation of A/R was not clear. Further, it’s dead-time seemed to have been
kept at 650 msec.
ICT-1, ICT-2 & ICT-3 trippings at 230 kV Mywady SS (TANTRANSCO):
 As per FIR/ TR, LV side CB’s of ICT-1,2 & 3 tripped at 6:23 hrs. due to 230 kV BBP operation of 230 kV Bus.
 It was informed that DR was not triggered as BBP is of static type.
 From the EL furnished, ICT-3 tripped at 6:28:11.101 hrs due to BBP operation. However, events corresponding
to ICT-1 & 2 were not shown/ recorded.
 Remedial Action:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 4/32
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Annexure- III
TANTRANSCO:
 To an enquiry regarding the possibility of providing Bus-sectionalizer CB, TANTRANSCO informed that Mywady
was a old substation, where there is severe space constraint for providing any additional protection features.
 When enquired about the possibility of providing two main zones for BBP, TANTRANSCO informed that the
existing busbar relay (B3 – Siemens make) does not support it. Further there is also no CT available for the buscoupler CB; as such with the present set-up, one main-zone only is possible. However, TANTRANSCO assured
that they will look into the issue, and explore the ways & means available like going for hybrid bus-coupler CB
that comes with inbuilt CT, replacing existing BBP relay with another suitable relay to provide two-zone
operation.
Recommendations:
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.
2. Details of Grid incidents:
घटनाकावििरण
/ तारीख/ Date &
श्रेणी/
कारण / Reason
Details of Event
Category
समय /Time
Tripping of 220kV
04-11-2015at
Ambewadi-Ponda lineLine tripped on operation of DEFR protection
13:09 hrs
2
As per FIR/ TR, the line tripped at 13:09 hrs due to backup DEFR operation.
As per EL, the line tripped at 13:09:21.305 hrs due to Äny Trip C”.
DR not furnished.
Remedial action:
 KPTCL informed that 220kV Ambewadi-Ponda lines are passing through dense forest area and subjected to
very high resistive faults. Resistive reaches in distance relays are revised in order to enable primary
protection to clear the faults. Revised settings adopted during January 2016.
Sr. No.
क्र.सं.
1




2
Line tripped on D.T. receive on CHANNEL-2 at
SV.Chatram end when the operator at
Tripping of 400kV
08-11-2015 at ALAMATHY S/S end tried to close AlamathyAlamathy-S.V.Chatram
10:48 hrs
SVChatram-1&2 Feeder Tie Breaker. Suspected
line-2
DC earth fault had caused the initiation of direct
trip.
SLD:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 5/32
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Annexure- III
SV Chatram (TANTRANSCO) end:
 As per FIR/DR/EL/TR, the line tripped at 10:46:20.920 hrs. due to DT receipt on Channel -2 from Alamathy end.
Alamathy (TANTRANSCO) end:
 As per FIR/ TR, at 10:12 Hrs on 8.11.2015, 400 KV Alamathy – S.V.Chatram-1 # Auto Reclose acted due to
passing fault. At that time, S.V.Chatram-1&2 # Tie breaker tripped (For Tie-CB, Auto reclose scheme not
available).
 At 10:45 hrs, while trying to close Tie-CB at Alamathy SS, DT was sent to SV Chatram line-2 end. No DT was
sent to SV Chatram line-1 end.
 No DR/EL furnished.
 Remedial Action:
 By availing LC on 13.11.2015, Direct Trip scheme for SVC -2 # was checked at Alamathy SS, and found to be
in order. At Alamathy 400 kV SS, due to heavy rain & entry of water in the cable trench, DC leakage was
observed. It is suspected that DC leakage is the cause for the above tripping.
 DC leakage was also observed in ICT-4 LV breaker and kept isolated.
NTPC-Ramagundam:
 Since the Tie-CB should not send DT when the Main-CB is in closed condition, Tie-CB scheme for sending DT to
the remote end may be checked.
Recommendations:
TANTRANSCO to provide A/R for 400 kV bay Tie-CB’s at Alamathy SS and SV Chatram SS.
Tripping of 400/220kV
10-11-2015 at
3
ICT-2
at
Chittoor
ICT-2 tripped on operation of overflux protection
00:53 hrs
substation
400 kV Chittoor-Krishnapatnam line-1:
SDSTPS (APGENCO) end:
 As per FIR/DR/EL, the line tripped at 00:53:32.933 hrs. due to DT receipt from Chittoor end.
Chittoor (APTRANSCO) end:
 As per FIR/DR/EL, the line tripped at 00:53:31.203 hrs. due to OVR, Stage-I operation.
ICT-2 Tripping (at Chittoor):
 As per FIR/DR, ICT-2 tripped at 00:53:24.094 hrs due to operation of OverFlux protection.
 In the furnished EL, this event was not recorded.
SRLDC:
 Previous to this tripping incident, ICT-1 was kept out of service due to PRD Oil Leakage.
 The approximate V/f ratio at the time of tripping has been calculated by taking Voltage values from DR anf
frequency values from PMU data, and are tabulated below:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 6/32
Page 6 of 32
Annexure- III
Where, V(m)/ f (m)  measured V/f ratio
V(n)/ f (n)  nominal V/f ratio
APTRANSCO:
 At Chittoor, ICT-2 Over Flux Relay (OFR) high setting was kept at 120 % with 100 msec delay.
 At the time of tripping of ICT-2, there were over voltage conditions prevailing at Chittoor due to which 400 kV
Chittoor – Krishnapatnam line-1 got tripped. This led to further momentary rise in voltage, and caused
operation of high-set unit of OFR.
 Remedial action:
 As a remedial measure, the high-set setting has been changed to 140 %, 100 msec.
 Upon enquiry by SRLDC, whether this change was also effected for the other ICT’s, APTRANSCO representative
replied in the affirmative.
10th Nov 2015
at 02:29hrs,
Tripping of ICT’s-1, 2, 3 3:49 hrs, 3:51
4
&
4
at
Salem hrs, 3:53 hrs ICT’s tripped on operation of overflux protection
substation
and 11th Nov
2015 at 4:42
hrs
 ICT – 1 & 2: 400/ 230 kV; ICT – 3 & 4: 400/ 110 kV
ICT-4 tripping on 10.11.2015 at 02:29 hrs:
 DR trigger time = 02:17:21.570 hrs. (But whether ICT-4 got tripped or not was not clear as there was no
change in current values)
 From EL, however, there were signals (i) ‘External OF’ at 02:21:56.689 hrs. and (ii) ‘Voltage per Hertz 1 – OP’
and OVER FLUX ON at 03:43:28.231 hrs at which ICT-4 seemed to have tripped. (So Exact time of ICT-4
tripping was not clear)
ICT-3 tripping on 10.11.2015 at 03:49 hrs:
 DR trigger time = 04:22:37.023 hrs. (But whether ICT-3 got tripped or not was not clear as there was no
change in current values)
 From EL, however, there were signals ‘Voltage per Hertz 1 – OP’ and OVER FLUX ON at 03:39:33.926 hrs. at
which ICT-3 seemed to have tripped.
ICT-2 tripping on 10.11.2015 at 03:51 hrs:
 DR trigger time = 03:49:57.827 hrs. (But whether ICT-2 got tripped or not was not clear as there was no
change in current values)
 From EL, Over Flux Operation for ICT-2 was observed from the signals ‘Voltage per Hertz 1 – OP’ and OVER
FLUX ON at 03:51:42.344 hrs.
ICT-1 tripping on 10.11.2015 at 03:53 hrs:
 DR trigger time = 04:14:12.691 hrs. (But whether ICT-1 got tripped or not was not clear as there was no
change in current values)
 From EL, however, there were signals ‘Voltage per Hertz 1 – OP’ and ‘OVER FLUX ON’ at 03:33:50.749 hrs. at
which ICT-1 seemed to have tripped.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 7/32
Page 7 of 32
Annexure- III
ICT-4 tripping on 11.11.2015 at 04:42 hrs:
 From DR/ EL, ICT-4 seemed to have got tripped at 04:35:13.201 hrs (From EL, the specific signal was External
OF).
TANTRANSCO:
 The Over Flux Relay (OFR) settings adopted for ICT’s at Salem are as follows:
 2.4 (110%), 3sec for ALARM
 2.4 (110%) as per curve for TRIP
 In the instant case, due to raise in 400 KV grid voltage, Over fluxing relay operated. The Frequency variation
from 49.90 Hz to 50.09 Hz was recorded during the tripping of all ICTs.
 It was also clarified that OFR’s operated as per their IDMT curves.
SRPC:
 Time-sync of DR’s and EL’s for all the four ICT’s at Salem substation shall be ensured by TANTRANSCO.
5
Tripping of 400kV NPS- 10-11-2015 at line tripped due to suspected DC earth fault at
NELLORE line-1
15:37 hrs
Nellore end and sent direct trip was sent to NPS
Nellore PS (PGCIL-SR1) end:
 As per FIR/DR/EL/TR, the line tripped at 15:37:25.696 hrs. due to DT receipt from Nellore-PG end.
Nellore-PG (PGCIL-SR1) end:
 As per FIR/DR/TR, the line tripped at 15:37:25.635 hrs. due to suspected DC Earth fault.
 As per EL, the line tripped at 15:50:47.031 hrs. due to 86B operation. (Actually, events before 15:37:34.102
hrs. were not found/ recorded.) However, there was a DT send event at 15:37:35.623 hrs.
 Time-sync of DR & EL with GPS needs to be checked.
PGCIL (SR-I):
 During the tripping event, there were heavy rains in Nellore area so much so that the rain water flooded the
substation. And the line tripped due to DC E/F caused by these continuous rains at Nellore.
 Remedial action:
 DC E/F removed.
SRPC:
 Time-sync of DR and EL at Nellore-PG end shall be properly ensured.
6
Tripping of HVDC 11-11-2015 at HVDC bhadrawati pole-2 tripped due to non-valid
GI-2
Bhadrawati pole-2
5:35 hrs
tap code alarm.
SRPC:
 It was noted that the relevant files (FIR/DR/EL/TR) of the tripping event had not been uploaded by WRTS-I in
spite of giving separate User ID & password to them for uploading files directly in SRLDC portal.
 As such, the tripping report had been sought from WRTS-1 after meeting, and the finding of it were
reproduced below:
 On 11.11.2015, Pole-1&2 were in service carrying total 800MW of power in W-S direction.
 The non-valid tap code alarm appeared in Pole-2 West side and pole-2 tripped at 05:3 hrs.
11-11-2015 05:35:31.606 EP47211TCA PC2W-M1.NON-VALID TAP CODE – ALARM
 Remedial action:
 On physical inspection, no abnormality observed in the tap positions of the Pole-2 west Converter
transformers. The tap positions were at bottom tap position i.e., position-01 after the tripping. Pole-2
was taken into service at 06:29 hrs.
 From the report, it appears that the Pole-2 had tripped on account of false Alarm generated by Tap Changer
Unit, hence the same may be kept under observation by WRTS-1, and in case of recurrence the issue may be
suitably addressed by changing tap-changer unit or taking up with its OEM.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 8/32
Page 8 of 32

Annexure- III
To get proper picture of the ground situation for the trippings such as above, it was decided that WRTS-1
representative should also be invited to PCSC meetings whenever tripping events relating to inter-regional
links (HVAC & HVDC) between WR and SR are slated for discussion.
Line tripped on operation of over voltage
Tripping of 400kV 11-11-2015 at
7
protection and pole discrepancy at Hoody end
Kolar-Hoody line-1
15:39 hrs
and direct trip was received at Kolar.
Kolar (PGCIL-SR2) end:
 As per FIR/ DR/ EL/ TR, the line tripped at 15:59:48.170 hrs due to DT receipt from Hoody end.
Hoody (KPTCL) end:
 As per FIR, the line tripped at 15:59 hrs due to operation of OVR and PDR.
 From DR, OVR trip was observed much before 86A trip relay operation (the latter was at 15:00:42.854 hrs). It
was also seen that only R & Y phases got opened, while the B-ph pole did not. So PDR might have operated to
open B-ph pole, but this was not shown in DR. High voltage in Y-ph (= 281 kV) was observed.
 EL not furnished.
 At Hoody OVR grading: Nelamangala-1 (D) > Kolar_PG -2 (C1) > Nelamangala-2 (B2) > Kolar_PG -1 (A),
Yelahanka -1 (A). So, the tripping due to OVR operation was not in order.
KPTCL:
 Due to 400kV bus PT core-2 cable problem in Kolar line-1, Control Relay Panel’s (CRP) Y-N voltage raised up to
280 kV and caused OVR trip. But only R&Y poles of the breaker got opened, and the B-pole did not open due to
burnt out trip coil. So the PD relay acted to open B-pole.
 Remedial action
 The faulty cable from Bus PT to CRP was replaced.
 The control valve assembly of B phase (problem in 89C isolator) was replaced.
R-phase to earth fault had occurred in Line. Line
did not auto-reclose from both ends. It was
Tripping of 400kV
12-11-2015 at mentioned that Y&B pole breakers at
8
Gooty-Nelamangala
00:20 hrs
Neelamangala tripped on operation of pole
line
discrepancy and backup impedence protection
for line reactor got operated.
Gooty (PGCIL-SR1) end:
 As per FIR/TR, the line tripped in 3-ph at 00:19 hrs on R-E fault due to DPR, Z1 operation [distance = 92.87 km
on Main-1 FL; distance = 115.52 km on Main-3 FL]. It was stated that GPS was not working.
 As per EL, the line tripped in 3-ph at 00:19:03.051 hrs due to operation of Main-1 protection.
 As per DR, the line tripped in 3-ph at 23:54:30.087 hrs on R-E fault.
 It is seen that A/R was not attempted; A/R lock-out was observed in EL.
 Time-sync problem with DR and EL.
 Remedial action:
 PGCIL (SR-I) informed that the line tripped on Transient R-N fault. A/R un-successful at GTY end due to 3Phase operation of THR Relay. The THR relay was replaced with Numerical Relay.
Nelamangala (KPTCL) end:
 As per FIR/DR/TR, the line tripped at 00:17:31.875 hrs. on R-E fault due to DPR, Z2 (CAT) operation. R-ph (of
Main-CB & Tie-CB) only got opened due to this, but the line did not try for auto-reclose after its dead-time of
1-sec. Finally after about 2.5 sec, the other two-phases (Y & B) of Main-CB & Tie-CB also got opened.
 It was stated in TR that at the time of tripping, Line Reactor (LR) tripped on Back up impedance relay and Autoreclose Lock out relay operated.
 EL furnished was not proper.
KPTCL:
 After opening of the line in R-ph due to A/R operation, the carrier link failed due to PLCC cards failure during
dead-time of A/R, due to which A/R went into lock-out. The Y & B ph-poles of the CB opened subsequently on
PDR operation.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 9/32
Page 9 of 32


Annexure- III
Remedial action:
 The failed PLCC cards were replaced by PGCIL (SR-I) at Nelamangala.
When asked by SRLDC on the reasons for operation of back-up impedance protection of the line reactor (LR),
KPTCL informed that they would revert with proper explanation.
 The unwarranted delay encountered in opening of the healthy phase poles of the CB in the event of PLCC link
failure during dead-time of A/R was discussed by the forum, and after ascertaining the views of various
Constituents, it was agreed that such delays can be avoided by giving a 3-ph trip immediately upon detecting
PLCC link failure during dead-time of A/R operation.
Recommendations:
For Gooty –Nelamangala line, PGCIL (SR-I) and KPTCL to provide 3-ph trip logic at their respective ends upon
detection of PLCC link failure during dead-time of A/R operation.
PGCIL (SR-)/ KPTCL to furnish reasons for operation of backup impedance protection of the Line Reactor at
Nelamangala end, and the remedial action taken.
PGCIL (SR-I) to make GPS functional at Gooty SS, and ensure time-sync of various DR’s and EL’s with it (GPS).
9
Tripping of Unit-3 & 4
Unit-3 and Unit-4 got tripped due to operation of
12-11-2015 at
at Simhapuri power
Local Breaker Backup (LBB) protection in both GT13:51 hrs
station
3 and GT-4 Bays
SRPC:
 It was noted that no representative from SEL attended the meeting to explain what exactly had happened at
SEL station that caused this tripping. So the details relating to tripped were sought vide SRPC mail 29.01.2016.
 As per the tripping details furnished by SEL vide their mail dated 04.02.2016:
 Unit-3 and Unit-4 were running with 123MW & 150 MW respectively.
 At 13:51hrs, both units got tripped. On investigation, it was found that the trip initiation had originated
from 400kV switchyard due to mal-operation of Local Breaker Backup (LBB) protection of CB-415.
 GT-3, TIE-3 & GCB-3 breakers of Unit-3 and GT-4, TIE-4 & GCB-4 breakers of Unit-4 were tripped. This led
to tripping of Unit-3 and Unit-4.
 Following are the sequence of events that caused outage of the Units.
 415 LBB 3-Ph operated in Bus bar protection relay Main-1. LBB protection trip initiated from Bus bar
protection relay.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 10/32
Page 10 of 32
Annexure- III

Due to this, LBB OPTD Auxiliary relays in GT-3 & GT-4 C&R panels have picked up, and tripped the GT-3
and GT-4 breakers.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 11/32
Page 11 of 32
Annexure- III



On receipt of LBB OPTD feedback, BCU in GT-3 and GT-4 panels issued trip command to respective TIE
and GCBs & TIE-3, 4 Master trip relays 86A & 86B operated.
From DR, it was observed that LBB of CB-415 operated at 13:51:14.386 hrs to open CB’s – 403, 406 & 415.
It was informed that mal-operation of 415 LBB protection was suspected to have been caused due to wrong
feedback entered from BBP relay, which in turn may be due to cable effected by moisture as cable was found
immersed in rain water.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 12/32
Page 12 of 32

Annexure- III
Remedial action:
 The faulty cable was replaced with a new one.
Tripping of 765/400kV
765/400kV ICT-2 at Nellore pooling station
14-11-2015at
ICT-2
at
Nellore
tripped due to mal-operation of PRD-OLTC
1:03 hrs
pooling station
Pressure High Trip B-ph
 As per FIR/EL/TR, ICT-2 tripped at 01:03:57.736 hrs. due to PRD-OLTC Pressure High Trip B-ph.
 From DR, the line tripped due to 86_B1 operation; however PRD2_TR_B remained at ‘zero’.
PGCIL (SR-I):
 The line tripped due to mal-operation of PRD Relay
 Remedial action:
 The issue was taken up with OEM and All the Buchholtz / PRD/ WTI / OTI Relays supplied under package
are being replaced by OEM.
 At NPS & Nellore-PG, replacement works already completed.
 At Nellore-PG & Nellore-AP also excepting for the line reactors on Vijayawada 3 & 4 feeders (at NelloreAP), replacement works for ICT’s and reactors were completed by the first week of January, 2016.
10
11
Tripping of 400kV
Neyveli TS2-Pugalur
line
14-11-2015 at
4:01 hrs
Line tripped on operation of over voltage
protection at Pugalur end. However from DR it
was observed that the voltages were below the
O/v stg-1 threshold limits
NLC TPS-II end:
 As per FIR, the line tripped at 04:01 hrs. due to DT receipt from Pugalur end.
 In EL, DT receipt event was not recorded.
 DR not furnished.
Pugalur (PGCIL-SR2) end:
 As per FIR/DR/EL/TR, the line tripped at 4:01:16.170 hrs due to OVR, Stage-I operation. The ph. voltages
observed are: 243.9 kV, 242.9 kV & 211 kV. These voltages seemed to be on the lower side for OVR
operation.
 At Pugalur, OVR grading: Chikanaurani-2 (D) > KV Pattu-1 (C2), NLC-II Exp-1 (C2) > NLC-II line-1 (C1) > KV Pattu2 (B2) > Chikanaurani-1 (B2)
Category
A
B1
B2
C1
C2
D
D2

Time Delay in Sec
10
9
8
7
6
5
4
Rating
110
110
110
110
110
109
109
The line tripping due to OVR, Stage-I operation was not in order.
Recommendations:
NLC to configure DT receipt event from Pugalur for triggering DR and EL at NLC TPS II.
PGCIL (SR-II) to check drop-off to pick-up ratio of OVR relay at Pugalur and configure its operation as per SRPC
provided OVR gradings.
12
Tripping of 400 kV
Nellore-Tiruvalam line-1
14-11-2015 at line tripped due to suspected Mal-operation of
14:04 hrs and
Line reactor PRD at Nellore end
at 12:12 hrs on
24-11-2015
Grid Occurrences discussed in PCSC-50 (27-01-2016) 13/32
Page 13 of 32
Annexure- III
Tripping on 14-11-2015 at 14:04 hrs:
Tiruvalam (PGCIL-SR2) end:
 As per FIR/DR/EL/TR, the line tripped at 14:04:23.162 hrs. due to DT receipt from Nellore-PG end.
Nellore-PG (PGCIL-SR1) end:
 As per FIR/DR/EL/TR, the line tripped at 15:39:39.502 hrs. due to mal-operation of LR PRD.
Tripping on 24-11-2015 at 12:12 hrs:
Tiruvalam (PGCIL-SR2) end:
 As per FIR/DR/EL/TR, the line tripped at 12:12:26.702 hrs. due to DT receipt from Nellore-PG end.
Nellore-PG (PGCIL-SR1) end:
 As per FIR/DR/EL/TR, the line tripped at 12:12:26.183 hrs. due to mal-operation of LR PRD.

Remedial action:
 PGCIL (SR-I) informed that the line tripped due to the mal-operation of PRD Relay. The issue was taken up
with OEM and All the Buchholtz / PRD/ WTI / OTI Relays supplied under package are being replaced by
OEM.
SRPC:
 Time-sync of DR’s & EL’s at Nellore-PG shall be ensured by PGCIL (SR-I).
16-11-2015 at line tripped due on protection system mal17:28 hrs and
operation due to heavy rain at Nellore
17:52 hrs
*** Files (DR/EL) uploading was not proper.
Trippping at 17:28 hrs:
NPS (PGCIL-SR1) end:
 As per FIR/TR, the line tripped at 17:28 hrs due to mal-operation of protection system. It was stated that heavy
inrush of rain water into substation at the time of tripping caused the line tripping.
 DR & EL uploaded were that of Nellore-PG. Therefore, no DR & EL furnished.
13
Tripping of 400kV
Nellore-NPS line-1
Nellore-PG (PGCIL-SR1) end:
 As per FIR/TR, the line tripped at 17:28 hrs due to mal-operation of protection system. It was stated that heavy
inrush of rain water into substation at the time of tripping caused the line tripping.
 From EL, DT send was observed at 17:28:17.553 hrs.
 From DR, DT send was observed at 17:28:17.812 hrs. (this DR was uploaded at NPS place)
 Remedial action
 PGCIL (SR-I) informed that the line tripped due to DC E/F which was caused by continuous rains at Nellore.
DC E/F was removed.
Trippping at 17:52 hrs:
NPS (PGCIL-SR1) end:
 As per FIR/TR, the line tripped at 17:52 hrs due to mal-operation of protection system. It was stated that heavy
inrush of rain water into substation at the time of tripping caused the line tripping.
 DR & EL uploaded were that of Nellore-PG. Therefore, no DR & EL furnished.
Nellore-PG (PGCIL-SR1) end:
 As per FIR/TR, the line tripped at 17:52 hrs due to mal-operation of protection system. It was stated that heavy
inrush of rain water into substation at the time of tripping caused the line tripping.
 From DR, DT receipt was observed at 17:52:31.949 hrs.
 From EL, DT send was observed at 17:52:31:740 hrs.
 Remedial action
 PGCIL (SR-I) informed that the line tripped due to DC E/F which was caused by continuous rains at Nellore.
DC E/F was removed.
SRPC:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 14/32
Page 14 of 32

14
Annexure- III
PGCIL (SR-I) should upload proper DR & EL in line with IEGC regulation 5.2(r) to analyze the cause of trippings.
Tripping of 220kV
Chittoor-Tiruvalam
18-11-2015 at
11:20 hrs
During testing of DC earth leakage, DC got
extended to bus bar protection relay. Hence bus
bar protection operated and tripped the 220KV
BUS connected transformers and feeders.
Tiruvalam (TANTRANSCO) end:
 As per FIR, there was no tripping at Tiruvalam end,
Chittoor (APTRANSCO) end:
 As per FIR, at the time of testing the DC earth leakage around 11:20 hrs, signal got extended to bus bar
protection relay. Hence bus bar protection operated and tripped the 220KV BUS connected PTRs and Feeders.
 DR & EL not furnished.
 Remedial action:
 APTRANSCO representative informed the earthing of 2-core cable from Tiruvalam to Bus bar got earthed
caused operation of the busbar protection; the faulty cable was replaced subsequently.
 From above, it appears that 220 kV side of 220/ 132 kV Chittoor SS is on single-bus operation with only one
main-zone.
Recommendations:
APTRANSCO to furnish SLD of 220/132 kV Chittoor SS,
APTRANSCO to confirm whether 220 kV side is on single-bus operation with only one main-zone. If so,
APTRANSCO shall examine the feasibility of providing split-bus operation or multiple main-zones for bus bar
protection, and take necessary steps to implement the same.
15
Tripping of 400/220kV
ICT-3 at Myvadi
substation
27-11-2015 at
11:21 hrs
ICT-3 Bus Voltage selection Relay 75B and 75D Y
ph contacts failed to operate. Due to that the
over flux relay of ICT 3 operated and initiated the
Group A and B relays.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 15/32
Page 15 of 32
Annexure- III

As per FIR/TR furnished by PGCIL (SR-II), ICT-3 Bus Voltage selection Relays’ (75B and 75D) Y-ph contacts failed
to operate. Due to that, the over flux relay of ICT-3 operated and initiated the Group A and B trip relays at
11:21 hrs.
 As per EL, ICT-3 tripped at 11:21:30.756 hrs due to OFR operation.
PGCIL (SR-II):
 Due to problem in Voltage Selection relay Y-ph contacts, Bus-1 and Bus-2 got shorted to result in momentary
spike in Y-ph voltage. Due to this, high-set of over flux relay of ICT-3 acted and tripped the same.
 Remedial action:
 The faulty voltage selection relay was replaced.

Tripping of 400kV
Alamathy-S.V.Chatram
lines - 1&2
16
27-11-2015 at
15:35 hrs
400KV Aalmathy-S.V.Chatram line-1 tripped on Bphase to earth fault. Line auto reclosed and at
both end subsequently A/R locked out due to
permanent fault
400KV Alamathy-S.V.Chatram line-2 Line tripped
on R-phase to earth fault. Line autoreclosed at
S.V.Chatram and failed to auto-reclose at
S.V.Chatram end.
400kV Alamathy – SV Chatram line – 1:
Alamathy (TANTRANSCO) end:
 As per FIR/DR/EL/TR, the line tripped in B-ph at 15:30:57.154 hrs. on B-E fault due to A/R operation. The line
successfully auto-reclosed at 15:30:58:154 hrs, but tripped in 3-ph due to persistent fault.
SV Chatram (TANTRANSCO) end:
 As per FIR/DR/EL/TR, the line tripped in B-ph at 15:35:29.144 hrs. on B-E fault due to A/R operation. The line
successfully auto-reclosed at 15:35:30:144 hrs, but tripped in 3-ph due to persistent fault. (Complete A/R
operation was not shown in DR).
 Remedial action:
 Line patrol conducted by Lines wing and observed that C-Phase jumper cut at Loc.no.176. Feeder declared
breakdown and the problem attended.
400kV Alamathy – SV Chatram line – 2:
Alamathy (TANTRANSCO) end:
 As per FIR/DR/EL/TR, the line tripped in 3-ph at 15:29:49.626 hrs. on R-E fault due to DPR, Z1 operation. The
line did not attempt for A/R.
SV Chatram (TANTRANSCO) end:
 As per FIR/DR/EL/TR, the line tripped in R-ph at 15:35:29.201 hrs. on R-E fault due to A/R operation (PUTT,
CAT), and successfully reclosed. (However, Complete A/R operation was not shown in DR).
Grid Occurrences discussed in PCSC-50 (27-01-2016) 16/32
Page 16 of 32
Annexure- III
Recommendations:
TANTRANSCO to check and ensure the healthiness of A/R scheme at Alamathy end on 400 kV Alamathy –
SV Chatram line – 2.
17
Tripping of 400/230kV
Myvadi ICT-3
27-11-2015 at
17:26 hrs
400/230kV Myvadi ICT-3 tripped due to the
operation of 230 kV CB LBB protection at 230 KV
bus (TNEB) of Myvadi station.
SLD:
SRLDC:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 17/32
Page 17 of 32
Annexure- III

No fault observe through PMU Data.
As per the report furnished by TANTRANSCO,
 On 27.11.2015, annual relay testing was carried out on the Bus Bar protection system available for Myvadi 230
kV bus.
 While actuating the final tripping mechanism, the LV 3 (LV side CB of ICT-3) alone tripped inadvertently, even
though the trip links were in removed condition.
 After normalizing the test procedures, the LV 3 was put into service.
 In coordination with PGCIL, LV3 LBB protection scheme was programmed for testing during Line Clear of LV 3
for routine maintenance on 05.12.2015. However, due to load conditions the LC on LV 3 could not be availed
on 05.12.2015.
 The above trip isolation link will be checked in due course on availing LC.
Recommendations:
TANTRANSCO to check the LBB scheme for LV-3, and furnish the remedial measures taken to PCSC forum.
400kV Hassan-Udupi line-2 tripped on Directional
earth fault protection with Y-E fault and direct
trip was sent to Udupi end. Directional Earth fault
feature of Main-2 relay at Hassan gave 3-ph trip
after 2.6 seconds and fault current in Y-phase was
Tripping of 400kV
1.1 kA. The distance as well as DEF protection for
UPCL-Hassan line-2
30-11-2015 at 400kV UPCL-Hassan line-2 at UPCL end did not
18
and running Units-1&2
GI-2
17:22 hrs
sense the fault. The generator transformer
at Udupi power
backup earth fault protection (51N) had sensed
station
the fault and tripped both the running units at
UPCL leading to generation loss at UPCL power
station. Back up directional earth fault protection
at 220kV side of 400/220kV ICT’s at UPCL did not
sense the high resistance fault in line-2
SLD:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 18/32
Page 18 of 32
Annexure- III
Hassan – UPCL Line2:
Hasan (PGCIL-SR2)end:
 As per FIR/DR/EL/TR, the line tripped at 17:20:55.885 hrs on Y-E fault due to DEFR operation, and sent DT to
the other end. There was a delay of 4.2 sec from the DEFR-Start ( 17:20:51.684 hrs.) to DEFR_Trip
(17:20:55.885 hrs.).
UPCL end:
 As per FIR/DR/TR, the line tripped at 17:22:07.258 hrs. due to DT receipt from Hassan end.
 EL furnished was not proper.
 Remedial action:
 The fault was of very high resistive in nature. From DR it can be seen that though there was fault in 'Y'
Phase with slow rise of current up to @1600 Amp, there was slight rise in the 'Y' Phase voltage and other
phases voltage were slightly reduced. The rise in Zero Sequence voltage w.r.t. Zero sequence current with
other phase parameters could not be detected by the relay as per Directional Earth fault characteristic.
 The polarisation used in the relay for direction decision is based on Zero Sequence detection. The
phenomena was referred ALSTOM with necessary testing at site. It has been recommended by ALSTOM
(OEM) to use negative sequence based Directional decision criteria to detect such high resistive fault with
in-feed effect.
Unit-1 tripping:
 As per FIR/DR/TR, Unit-1 tripped at 17:21:00.280 hrs. due to I(N)>1 trip, i.e., GT’s non-directional EFR
operation.
 EL furnished was not proper.
Unit-2 tripping:
 As per FIR/Dr/EL/TR, Unit-2 tripped at 17:21:00.280 hrs. due to I(N)>1 trip, i.e., GT’s non-directional EFR
operation.
KPTCL:
 The fault was a high-resistance one with slow rise of fault current. Further due to the use of zero-sequence
polarization, the voltage dip obtained was not sufficient to operate DEFR immediately. During this delay in
DEFR operation, the back-up non-directional E/F relays of GT’s of Unit-1 & 2 have picked up and tripped the
corresponding breakers. This resulted in tripping of both Units due to loss of evacuating lines.
 Remedial action:
 Previously two earthings have been provided to CT neutral. Now one earthing has been removed.
 As suggested by Alstom, negative sequence polarization instead of zero sequence polarization has been
made use of to detect high resistive faults with in-feed effect.
SRLDC:
 Different make relays should be provided for Main-1 & Main-2 at UPCL on UPCL – Hassan lines.
 Also the Time-sync problem between DR & EL’s of Line and GT relays needs to be attended by UPCL at the
earliest.
Recommendations:
UPCL to provide different make relays for Main-1 & Main-2 at UPCL end on 400 kV UPCL – Hassan lines – 1 & 2.
UPCL to make GPS functional at their Station and ensure time-sync of various DR’s and EL’s with GPS.
19
Tripping of 400kV Bus2 at Kalpakka, 400kV
Kalpakka-Simhadri-I
line4, 400kV KalpakkaVemagiri-line2, ICT-2
at Kalpakka
10-12-2015 at
15:20 hrs
While testing new 400kV Hinduja Power station
feeder bay in the yard, trip pulse got extended to
GI-2
Bus-2 of Busbar protection and all connected
feeders to Bus-2 got tripped
SLD:
 The SLD of 400/220 kV Kalpakka SS as provided by APTRANSCO is attached at the end.
Kalpakka-Vemagiri line-2:
Vemagiri (APTRANSCO) end:
Grid Occurrences discussed in PCSC-50 (27-01-2016) 19/32
Page 19 of 32
Annexure- III


As per FIR, the line was holding.
As per DR/EL, the line tripped at 15:20:08.249 hrs. due to DT receipt from Kalpakka end.
Kalpakka (APTRANSCO) end:
 As per FIR, the line tripped at 15:20 hrs. due to BBP operation. It was stated that while testing the new 400kV
Hinduja Power co ltd feeder bay in the yard, trip pulse got extended to Bus-2 of Bus-bar protection and all
connected feeders to Bus-2 got tripped.
 As per DR, the line tripped at 15:22:08.804 hrs. due to BBP operation of Bus-2.
 As per EL, the line tripped at 15:20:28.725 hrs. hrs. due to BBP operation of Bus-2. [Effected bays are Bay-5
(ICT-2), Bay-8 (STPP-4), Bay-9 (Vem-2), Bay-11B (Bus Section-2 CB)]
Kalpakka-Simhadri I line-4:
Simhadri (NTPC) end:
 As per FIR/DR/EL, the line tripped at 15:20:35.725 hrs. due to DT receipt from Kalpakka end.
Kalpakka (APTRANSCO) end:
 As per FIR, the line tripped at 15:20 hrs. due to BBP operation. It was stated that while testing the new 400kV
Hinduja Power co ltd feeder bay in the yard, trip pulse got extended to Bus-2 of Bus-bar protection and all
connected feeders to Bus-2 got tripped.
 As per DR, the line tripped at 15:21:47.334 hrs.
 As per EL, the line tripped at 15:20:28.725 hrs. hrs. due to BBP operation of Bus-2. [Effected bays are Bay-5
(ICT-2), Bay-8 (STPP-4), Bay-9 (Vem-2), Bay-11B (Bus Section-2 CB)]
ICT-2 Tripping:
 As per FIR, the ICT-2 tripped at 15:20 hrs. due to BBP operation. It was stated that while testing the new 400kV
Hinduja Power co ltd feeder bay in the yard, trip pulse got extended to Bus-2 of Bus-bar protection and all
connected feeders to Bus-2 got tripped.
 As per EL, ICT-2 tripped at 15:20:28.725 hrs. hrs. due to BBP operation of Bus-2. [Effected bays are Bay-5 (ICT2), Bay-8 (STPP-4), Bay-9 (Vem-2), Bay-11B (Bus Section-2 CB)]
NTPC-Simhadri:
 Whenever any testing is carried out on the switchyard equipment at Kalpakka SS that has a bearing at
Simhadri end (through Kalpakka – Simhadri lines), APTRANSCO should keep them informed for better
preparedness. To this, APTRANSCO representative assured that Simhadri personnel would be taken into
confidence as suggested.
20
Tripping of HVDC 06-12-2015 at
Bhadrawati Pole-2
07:09 hrs
HVDC pole-2 tripped due to non-valid tap code
GI-2
alarm.
SRPC:
 It was noted that the relevant files (FIR/DR/EL/TR) of the tripping event had not been uploaded by WRTS-I in
spite of giving separate User ID & password to them for uploading files directly in SRLDC portal.
 As such, the tripping report had been sought from WRTS-1 after meeting, and the finding of it were
reproduced below:
 On 06.12.2015, at 07:09hrs Pole-1 & 2 carrying 800MW,W-->S direction.
 At 07:09hrs, Pole-2 tripped on " PC2W-M1.NON-VALID TAP CODE - ALARM".
06-12-2015 07:08:47.729 EP471R3A POLE-1 PC1 TAPCHANGE MINOR ALARM WEST - ALARM
06-12-2015 07:08:47.763 EP471R3A POLE-1 PC1 TAPCHANGE MINOR ALARM WEST - NORMAL
 06-12-2015 07:09:01.490 EP47211TCA PC2W-M1.NON-VALID TAP CODE – ALARM
 Remedial action:
 On physical inspection, no abnormality observed in the tap positions of the Pole-2 west Converter
transformers. The tap positions were at bottom tap position i.e, position-01 after the tripping.
 Tap Raise/Lower commands were checked in group and individual. The Tap Raise/Lower commands
Grid Occurrences discussed in PCSC-50 (27-01-2016) 20/32
Page 20 of 32
Annexure- III


were found to be operating correctly.
 Pole-2 was deblocked at 07:53Hrs.
From the report, it appears that the Pole-2 had tripped on account of false Alarm generated by Tap Changer
Unit, hence the same may be kept under observation by WRTS-1, and in case of recurrence the issue may be
suitably addressed by changing tap-changer unit or taking up with its OEM.
To get proper picture of the ground situation for the trippings such as above, it was decided that WRTS-1
representative should also be invited to PCSC meetings whenever tripping events relating to inter-regional
links (HVAC & HVDC) between WR and SR are slated for discussion.
Y-phase to earth fault had occurred in 220kV
Tripping of 400/220kV
Shoranur-Madakathara line due to snapping of
06-12-2015 at
21
ICT-3 at Madakathara
earth wire. ICT-3 at Madakathara tripped on
13:50 hrs
substation
operation of differential and REF protection for
this through fault.
 As per DR/EL, Y-ph Unit of ICT-3 tripped at 13:50:30:406 hrs / 13:50:30.444 hrs due to operation of REF /
Differential protection.
KSEB:

It was informed that this tripping had happened during voltage recovery after clearance of the fault.
Therefore, by monitoring two phases to sense the 2nd harmonic content, there are better chances of checkmating differential relay mal-operation during transient arcings such as that encountered in the instant case.
Tripping of 400kV
Operation of reactor Backup Impedance
10-12-2015 at
Vijayawada-Nellore
protection resulted in tripping of line. Direct trip
10:51 hrs
(AP) line-3
was sent to Nellore (AP)
Nellore-AP (APTRANSCO) end:
 As per FIR, the line tripped at 10:51 hrs. due to DT receipt from Vijayawada end.
 DR & EL not furnished.
Vijayawada (PGCIL-SR1) end:
 As per FIR/TR, the line tripped at 10:51 hrs due to operation of Backup Impedance Protection of the Line
Reactor.
22
Grid Occurrences discussed in PCSC-50 (27-01-2016) 21/32
Page 21 of 32



Annexure- III
From DR, Main-CB was found to be in OPEN condition even before the tripping event. Only Tie-CB got opened
at 10:51:32.735 hrs. due to operation of 3-ph Group-A & B trip relays.
As per EL, the line tripped at 10:51:34 hrs. due to operation of 3-ph Group-A & B trip relays.
EL was not configured to record events at msec. level.
PGCIL (SR-I):
 Prior to the tripping event, bus shutdown was taken at Vijayawada. However, the bus CVT voltage selection
relay which was supposed to operate within 1 sec took abnormally longer time of 3 sec to effect changeover,
during which time the back-up impedance protection of the line reactor picked up and tripped the feeder.
 Remedial action:
 The faulty voltage selection relay has been replaced with spare.
3. Failure or non-operation of Auto reclose during transient fault
Sr.
No.
1
Date &
Time
Element
Tripping of 400kV GajwelShankarapalli line-1
02-11-2015 at
11:33hrs and 12:22
hrs
Reason
Line tripped on an R-phase to earth fault
and fault was persistent. From PMU data it
was observed that the breaker tried two
auto-reclose attempts after dead time.
Tripping at 11:33 hrs
Gajwel (TSTRANSCO) end:
 As per FIR, the line tripped at 11.33 hrs on R-E fault due to DPR, Z1 operation.
 DR & EL not furnished.
Shankarapalli (TSTRANSCO) end:
 As per FIR/DR/EL, the line tripped at 11:33:03.460 hrs on R-E fault due to A/R operation. It successfully
reclosed after 1 sec, but tripped again (at 11:33:04.734 hrs) due to persistent fault.
 DR furnished does not show A/R closing and opening again due to persistent fault.
 From PMU data, two auto-reclose attempts were seen.
Tripping at 12:22 hrs
Gajwel (TSTRANSCO) end:
 As per FIR, the line tripped at 12:22 hrs on R-E fault due to DPR, Z1 operation.
 DR & EL not furnished.
Shankarapalli (TSTRANSCO) end:
 As per FIR/DR/EL, the line tripped at 12:22:10.478 hrs on R-E fault due to A/R operation. It successfully
reclosed after 1 sec, but tripped again (at 12:22:11.678 hrs) due to persistent fault.
 DR furnished does not show A/R closing and opening again due to persistent fault.
 From PMU data, two auto-reclose attempts were seen.
SRPC:
 It was noted that no representative from TSTRANSCO attended the meeting.
 It was also noted that TSTRANSCO had not uploaded the relevant tripping files (DR & EL) for Gajwel end even
after 85 days had elapsed from the day of tripping event, which is an inexcusable violation of IEGC regulation
5.2 (r).
2
Tripping of 220kV KaniambetaKadakola line
04-11-2015at 12:38
hrs
Line tripped on a B-phase to earth fault.
There is no provision for auto-reclose for
Grid Occurrences discussed in PCSC-50 (27-01-2016) 22/32
Page 22 of 32
Annexure- III
line
Kadakola (KPTCL) end:
 As per FIR, the line tripped at 12:38 hrs on B-E fault due to DPR, Z1 operation (distance = 70.8 km from
Kadakola)
 Remedial action:
 KPTCL informed that 1-ph A/R feature had been enabled on 29.12.2015
Kaniyampeta (KSEB) end:
 As per FIR, the line tripped at 12:39 hrs on B-E fault due to DPR, Z1 operation (distance = 32.47 km from
Kaniyampeta)
 Remedial action:
 KSEB informed that line patrolling was conducted, it was suspected as a semi permanent fault in the
maintenance area of Kadakola. (The fault location is around 35km).
Tripping of 220kV Ambewadi-Ponda
11-11-2015 at
Line tripped on a B-phase to earth fault.
line
11:32hrs
There is no provision for auto-reclose.
Ambewadi (KPTCL) end:
 As per FIR/DR/EL, the line tripped (in 3-ph) on B-E fault at 11:32:43.209 hrs due to DPR, Z1 operation (distance
= 4.267 km)
 Remedial action:
 KPTCL informed that it was a transient fault. Line inspection was carried out but fault could not be located.
Charged as per SLDC instructions.
SRPC:
 When asked about the line currents (R & Y) currents persistence (DR observation) event after DPR, Z1
operation. KPTCL informed that they would revert with proper explanation.
 In this context, the status of providing Carrier-aided protection and Auto-reclosure on Ambewadi- Xeldem line
was discussed, to which KPTCL informed that though PLCC panel works had been completed from their end,
the status of the same at Xeldem end needed to be found out.
 On this, KPTCL was requested to furnish a Compliance/ Action Taken report on the recommendations given by
the Committee that visited these stations during 9-11 April, 2015 to ascertain the problems in the transmission
lines feeding Goa from Karnataka from the Southern Region. It was also decided to obtain Compliance/ Action
taken report from the Electricity Department of Goa.
3
Tripping of 400kV NCTPS-S.V.Chatram
line-2
16-11-2015 at 17:24
hrs
4
Line tripped on a Y-phase to earth fault.
Line auto-reclosed at S.V.Chatram and
failed to auto-reclose at NCTPS. It was
mentioned in FIR of NCTPS that the tie
breaker was under shutdown.
NCTPS (TANGEDCO) end:
 As per FIR/DR/EL/TR, the line tripped (in 3-ph) at 17:24:59.165 hrs on Y-E fault due to DPR, Z1 (CAT) operation.
 It was stated in TR that A/R was under lock-out.
 From DR, Tie-CB seemed to be in OPEN condition at the time of tripping.
SV Chatram (TANTRANSCO) end:
 As per FIR/DR/EL/TR, the line tripped (in 1-ph) at 17:24:59.494 hrs on Y-E fault due to A/R operation, and
successfully auto-reclosed after 1 sec.
 It was stated that Tie-CB had been kept out of service at the time of tripping.
 It was observed from DR that line currents were present in R & B phases during A/R dead time.
TANGEDCO:
 Remedial action:
 A/R did not operate at NCTPS end due to wiring problem in BCU, which was subsequently rectified.
 On a query by SRLDC whether TANGECO had checked the operation of A/R on other feeders for any wiring
Grid Occurrences discussed in PCSC-50 (27-01-2016) 23/32
Page 23 of 32
Annexure- III
related problems in corresponding BCU’s, TANGEDCO representative informed in the affirmative.
Tripping of 400kV KrishnapatnamChitoor line-1
16-11-2015 at 18:49
hrs
5
Line tripped on a permanent fault in Rphase. Chittoor end attempted for autoreclose however Krishnapatnam end went
for a 3 phase trip and did attempt for autoreclose.
Chittoor (APTRANSCO) end:
 As per FIR/DR/EL, the line tripped (3-ph) at 18:23:44.589 hrs on R-E fault due to A/R operation. Line
successfully auto-reclosed after 1sec, but due to persistent fault. line tripped again in 3-ph.
SDSTPS (APGENCO) end:
 As per FIR/DR/EL, the line tripped (3-ph) at 18:23:47.994 hrs on R-E fault due to DPR, Z1 operation (distance =
18.10 km).
 In DR, digital signals were not shown.
APGENCO:
 At the time of tripping, A/R was not kept in service.
 Remedial action:
 Line-by-line shutdown was availed during 16-22 December, 2015, and on all 400 kV feeders emanating
from SDSTPS, A/R was put into service.
6
Tripping of 220kV GummidipoondiSullurupeta line
03-12-2015 at
09:05hrs
Line tripped on a Y-phase to ground fault.
There is no provision for auto-reclose for
line.
Sullurupeta (APTRANSCO) end:
 As per FIR/DR/EL, the line tripped (in 3-ph) at 09:05:51.566 hrs on Y-E fault due to DPR, Z1 operation.

Gummidipoondi (TANTRANSCO) end:
 As per FIR, the line tripped (in 3-ph) at 09:11:51.566 hrs on Y-E fault due to DPR, Z1 operation. (Distance =
23.26 km)
 As per DR/EL, the line tripped in 3-ph at 08:09:24.858 hrs. on Y-E fault due to DPR, Z1 operation.

Remedial action:
 APTRANSCO informed that A/R has been kept into service from Sullurupeta end on 19.1.2015.
 TANTRANSCO informed that A/R is yet to be enabled from Gummidipoondi end due to high operating time
of the circuit breaker. However, they assured that it would soon be resolved, and A/R would be made
functional at the earliest.
 For all the above cases of A/R non-operation, the time scale for the DR should be properly configured, say two
sec, post triggering to capture complete A/R operation.
Grid Occurrences discussed in PCSC-50 (27-01-2016) 24/32
Page 24 of 32
Annexure- III
4. Lines tripping due to tripping at one end/PLCC mal-operation
Sr.
No.
क्र.सं.
घटनाकावििरण / Details तारीख/ Date &
of Event
समय /Time
1
Tripping
of
400kV 8-11-2015
Pugalur-Karaikudi line-2 13:51hrs
कारण / Reason
at line tripped at Karaikudi and was holding from Pugalur due to
suspected PLCC mal-operation at Karaikudi end.
Pugalur (PGCIL-SR2) end
 As per FIR, the line was kept holding.
Karaikudi (PGCIL-SR2) end
 As per FIR/DR/EL/TR, the line tripped at 13:51:58.469 hrs due to DT receipt from Pugalur end. (Rx-Counter
Increment was also observed.)
 Remedial action:
 PGCIL-SR2 informed that the line tripped at Karaikudi end only on receipt of DT. Suspected PLCC maloperation. The Signal Levels at HF and Card level carried out at both ends, and found healthy.
Tripping
of
400kV
21-11-2015at
Line tripped at Krishnapatnam end only on pole discrepancy
2
Krishnapatnam-Chitoor
7:18 hrs
operation
line-1
Chittooor (APTRANSCO) end:
 As per FIR, line-1 was kept holding.
SDSTPS (APGENCO) end:
 As per FIR/DR/EL, the line tripped at 07:18:52.627 hrs due to PDR operation.
 APGENCO representative informed that at the time of tripping, it was heavily raining, and some DC earth lease
was suspected to have caused the tripping.
Tripping of 400 kV
06-12-2015 at
3
Neyveli TS2-Eeyveli TS-I
lines tripped due to suspected mal-operation of PLCC
23:12 hrs
(EXP) and
NLC TPS-I (Exp.) end:
 As per FIR/ TR, the line tripped at 23:12 hrs due to DT receipt from NLC TPS-II end.
 DR & EL not furnished.
NLC TPS-II end:
 As per FIR, the line tripped at 23:11 hrs due to OVR operation at remote end.
 DR not furnished.
 EL furnished does not show any events relating to this tripping.
NLC:
 The line tripped at NLC TPS-I Expn. only, and was caused due to PLCC Channel-II problem.
 Remedial action:
 PLCC Channel-II problem at NLC TPS-I Expn. attended.
 They were facing problems in uploading DR & EL files in the SRLDC web portal. To this, SRLDC clarified that in
case any Constituent faces any problem in uploading tripping files, they should inform the same to SRLDC, and
get the problem resolved.
Tripping of 400 kV
06-12-2015 at
Neyveli TS 2 - Neyveli TS
lines tripped due to suspected mal-operation of PLCC
20:35 hrs
I EXP
NLC TPS-II end:
 As per FIR, the line was kept holding.
NLC TPS-I (Exp) end:
4
Grid Occurrences discussed in PCSC-50 (27-01-2016) 25/32
Page 25 of 32



5
Annexure- III
As per FIR/ TR, the line tripped at 20:35 hrs due to DT receipt from NLC TPS-II end.
DR & EL not furnished.
Remedial action:
 NLC informed that the feeder tripped with DT indication at TPS-I Expn. But the other end (TS 2) breaker
was holding. No abnormality/ relay pick up was noticed and feeder was charged at 23:03 hrs.
Tripping of 400kV NCC- 10-12-2015at
TPCIL line
3:48 hrs
line tripped due to mal-operation of PLCC and direct trip was
received at TPCIL end
NCC end:
 It was informed that line was kept holing during the tripping event.
TPCIL end:
 As per FIR, the line-1 tripped at 03:41:25 hrs due to DT receipt from NCC end.
 From DR/EL, the line-1 tripped at 03:41:18.253 hrs. due to DT receipt from the remote end.
 Remedial action:
 TPCIL informed that there was a problem with PLCC tuning frequency, due to which it mal-operated to trip
the line. Subsequently, it was rectified.
For all the above cases of PLCC mal-operation, the following shall be carried out by the concerned
Constituents in co-ordination.
 Healthiness of PLCC system components (hardware and software) at both ends shall be checked and faulty
components shall be repaired/ replaced.
 End-to-end communication for DT/ permissive & other signals may be ensured by testing at both the ends.
*****
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Annexure- III
SLD of 220 kV Somanahalli SS of KPTCL (Ref: I.1)
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Annexure- III
Grid Occurrences discussed in PCSC-50 (27-01-2016) 28/32
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Annexure- III
SLD of TPCIL (Ref: I.2)
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Annexure- III
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Annexure- III
SLD of 230 kV Myvadi SS of TANTRANSCO (Ref: I.3)
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Annexure- III
SLD of 400/220 kV Kalpakka SS of APTRANSCO (Ref: II.19)
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Annexure-IV
Pending Implementation of PCSC Recommendations (30th to 50th)
Meet
ing
No /
Index
Details of
Event
Date
Reason
PCSC Recommendations
Utility
Responsible
for
implementa
tion
Status of Recommendations
as on
Remarks
Andhra Pradesh
42/II/3 Outage at
21-02-2015
Regulapadu
at
station of
00:49 hrs
APTRANSCO
Y-Ph Metering PT failed at 220KV
Ragulapadu Substation. Fault got cleared
by tripping of lines from remote ends.
 APTRANSCO to furnish the remedial measures taken in APTRANSC Mail received on 27-05-2015:
Pending
consequent to the tripping
O
1)Failed metering PT was replaced with new PT.
incident along with the status of bus bar protection and bus
2) 220kV Ragulapadu is a single bus system. Hence there is no provision for
coupler at Regulapadu S/s.
bus coupler at Ragulapadu SS.
 A/R feature to be enabled on Regulapadu – Alipuira 220
Mail received on 24-06-2015:
APTRANSCO Vide Ltr. Dt. 23/06/2015, requested KPTCL to furnish the details
kV inter-state line.
of available tele protection equipments and details of the equipments going to be
procure for enabling the carrier aided protection on 220KV Ragulapadu-Alipura
line. Based on the KPTCL information we will take further necessary action.
Mail recieved on 22-08-2015:
APTRANSCOhas planned to commission ABB make ETL-41 type PLCC
terminal along with NSD-50 type protection coupler at Ragulapadu end towards
Alipura. vide our Ltr Dt 23-07-2015, it is requested KPTCL to arrange ABB
make ETL-41 cabinet with NSD-50 type protection coupler for establishing PLC
communication between Alipura- Ragulapadu.
KPTCL Mail recieved on 23-01-2016:
KPTCL is ready with ETL-41 cabinet with NSD-50 type protection coupler at
Alipur end.
45/II/1 Tripping of
4
400/220 kV
ICT-1&2 at
Gooty
substation
31-05-2015at As per FIR, ICT-1&2 tripped on operation of
06:37 hrs
directional overcurrent and earth fault
protection. It was reported that there was fault
in 220kV APTRANSCO system
1. APTRANSCO to check resistive reach of the distance
APTRANSC Yet to be informed
relays on 220 kV Gooty SS – Gooty RS line
O
2. APTRANSCO to check time coordination of distance
relay on Gooty SS – Gooty RS line at Gooty SS with Gooty
ICT’s (1 & 2) back-up protection.
Pending
49/II/8 Tripping of
25-10-2015
400kV
at 10:56 hrs
VemagiriSattenapalli
line and 400kV
VemagiriKalpakka line
B-phase to earth fault had occurred in line.
APTRANSCO to furnish a report on the tripping of 400 kV APTRANSC Yet to be informed
From Vemagiri end D.R, three phase trip and Vemagiri – Sattenapalli line along with relevant DR & EL
O
Tie-CB LBB operated was observed.
showing clearly the successful operation of A/R followed by
Sattenapalli end had auto-reclosed, however
T-LBB/ OVR, Stage-I operation.
breaker at Satenapalli tripped 8 sec after A/R
on receipt of DT from Vemagiri as observed
from EL of Satenapalli station.
For 400k Vemagiri-Kalpakka line at Vemagiri
end, Tie LBB operation and Grp-A/B trip was
observed and direct trip was sent to Kalpakka
end.
Pending
49/II/1 Tripping of
31-10-2015
3
running Units 1 at 03:30 hrs
& 3 at
Rayalaseema
TPS of
APGENCO
While synchronizing Unit-5 with grid, Bus bar In view of the availability of 25AX, APGENCO shall keep APGENCO
protection of 220kV Bus-1 operated which
synchronizing facility in auto-mode after getting it’s
resulted in de-energization of 220kV Bus-1.
operation verified by its OEM, M/s BHEL.
This resulted in tripping of running Unit1&Unit-3, 220kV lines Pulivedula-1,
Yeralaguntla-1, Chinakampalli-1, Timmapura
Pending
Page 1 of 18
Yet to be informed
Annexure-IV
49/III/ Tripping of
19-10-2015
4
400kV
at 07:49 hrs
KrishnapatnamChittoor line-1
R-phase to earth fault had occurred in line.
Chittoor end tried for auto-reclose. However,
due to persistent fault, breaker at Chittoor end
tripped. Krishnapatnam end relay did not try
for auto-reclose and gave a 3 phase trip as
observed from D.R
• APGENCO to make A/R functional on all lines emanating APGENCO
from Krishnapatnam TPS by 10th December, 2015.
50/II/1 Tripping of
4
220kV
ChittoorTiruvalam
18-11-2015
at 11:20 hrs
During testing of DC earth leakage, DC got
extended to bus bar protection relay. Hence bus
bar protection operated and tripped the 220KV
BUS connected transformers and feeders.
1.APTRANSCO to furnish SLD of 220/132 kV Chittoor
SS,
2. APTRANSCO to confirm whether 220 kV side is on
single-bus operation with only one main-zone. If so,
APTRANSCO shall examine the feasibility of providing
split-bus operation or multiple main-zones for bus bar
protection, and take necessary steps to implement it.
44/III/ Tripping of
2
400kV
GhanapurMamidapalli
line
15-04-2015
at 2:03 hrs
47/II/6 Tripping of
400kV
KhammamKTPS line-2
30-07-2015
at 6:08 hrs
Yet to be informed
Pending
APTRANSC Yet to be informed
O
Pending
Line tripped at Mamidapalli end only and was TSTRANSCO to make DR
holding at Ghanapur. Overvoltage protection functional at Mamidipalli
had operated at Mamidapalli
TSTRANSCO TSTRANSCO informed vide their mail dated 24.06.15 that the existing relays
would be replaced with numerical relays in DPR works.
Pending
Y-phase to earth fault had occurred in line.
From Khammam end DR it was
observed that the relay after dead time tried for
auto-reclose. The fault was
persisting and relay gave a single phase trip
instead of a 3 phase trip after 1.25sec. R& B
pole voltage dip after 2 sec
possibly due to operation of pole discrepancy.
Auto-reclose close command observed after
2.5 seconds and all poles got closed.
TSGENCO
Yet to be informed
Pending
Telangana
1. TSGENCO to check the reclaim time of A/R and set it at
25 sec at KTPS.
2. TSGENCO to carry out PLCC end-to-end testing in
coordination with PGCIL (SR-I) for KTPS – Khammam
line-2; retrofitting of Protection Coupler may be carried out
based on the test results.
48/II/5 Tripping of
07-09-2015
400kV
at 2:58 hrs
NagarjunsagarMahboobnagar
line
Line tripped on operation of over-voltage
TSTRANSCO to furnish a detailed report on the tripping
protection at Mahboobnagar and direct trip
event along with remedial measures taken to PCSC forum.
received at N’sagar station. DT receive was
observed in DR and EL of N’sagar station.
D.R/EL of Mahboobnagar was not furnished to
validate the overvoltage tripping
TSTRANSCO Yet to be informed
Pending
48/III/ Tripping of
20-09-2015
4
220kV Gajwel- at 2:24 hrs
Shankarapally
line
line tripped at Gajwel end on R-Phase to
ground fault. Reason for non-auto reclose
could be established as DR and EL of both
ends were not furnished
• TSTRANSCO to furnish a detailed report on the tripping
event along with remedial measures taken to PCSC forum.
TSTRANSCO Yet to be informed
Pending
30/I/A RTPS
Mar-14
Tripping
incidents and
the Spl meeting
held
Spl meeting held at RTPS on 13th and 14th
March 2014
The PCSC forum recommended for replacement of
KPCL
existing electromechanical relays with Numerical relays.
Karnataka
at RTPS on
13th and 14th
March 2014
Mail recieved on 21-10-2015 and 23-11-2015:
1) Replacement of Old electromagnetic relays with Numerical relays has been
completed for RTPS-BTPS line & commissioned on 18.03.2014.
Raichur-PG1 & Raichur-PG2 lines have already retrofitted with numerical
relays.
The retrofitting of electromechanical relays with Numerical version for the
following lines/ICTs have been completed/commissioned as follows:
a) ICT-2 –Commissioned on 01-08-2015
b) ICT-1 ---Commissioned on 08-08-2015
c) Munirabad line--- Commissioned on 16-08-2015.
d) Mehaboobnagar line-- Commissioned on 09-09-2015.
Page 2 of 18
2. Job order placed on 26.06.2015 on M/s Alstom T&D India Ltd. Chennai for
retrofitting of relays for all 220kV lines at RTPS.
3. Retrofit of existing bus bar(CAG-34) with numerical version– Budgetary
offers obtained and is under process.
Pending
30/I/A RTPS
Mar-14
Tripping
incidents and
the Spl meeting
held
Spl meeting held at RTPS on 13 and 14
March 2014
The PCSC forum recommended for replacement of
KPCL
existing electromechanical relays with Numerical relays.
Mail recieved on 21-10-2015 and 23-11-2015:
1) Replacement of Old electromagnetic relays with Numerical relays has been
completed for RTPS-BTPS line & commissioned on 18.03.2014.
Raichur-PG1 & Raichur-PG2 lines have already retrofitted with numerical
relays.
Pending
Annexure-IV
at RTPS on
13th and 14th
March 2014
The retrofitting of electromechanical relays with Numerical version for the
following lines/ICTs have been completed/commissioned as follows:
a) ICT-2 –Commissioned on 01-08-2015
b) ICT-1 ---Commissioned on 08-08-2015
c) Munirabad line--- Commissioned on 16-08-2015.
d) Mehaboobnagar line-- Commissioned on 09-09-2015.
2. Job order placed on 26.06.2015 on M/s Alstom T&D India Ltd. Chennai for
retrofitting of relays for all 220kV lines at RTPS.
3. Retrofit of existing bus bar(CAG-34) with numerical version– Budgetary
offers obtained and is under process.
34/III/ 400kV
26-06-2014
1
Raichur-BTPS
line
Transient fault in R-phase.
Line did not auto reclose
A/R at BTPS end to be made operational within one
month
KPCL
1. A/R for 220kV lines enabled already.
2. Shut down of lines availed to commission the auto reclosing schme for 400
kV line at BTPS.
Pending
Mail recieved on 21-10-2015:
Timer relays have been received at site. A letter has been addressed to M/s
Alstom to complete the work on priority basis.
Mail recieved on 23-11-2015:
Commissioning of Autorecloser planned on 14, 15 & 16th of Dec-2015 subject
to availability of LC.
38/G GD-1 at Kadra 13-11-2014
D/3.5 and Kodasalli at 19:31hrs
hydro power
station
A fault had occurred in 220 kV Kadra and
Kodasalli. As A result, de-energization of
220kV bus occurred at Kadra and
Kodasalli.
1. The PCSC forum requested KPCL to speed up the
installation of Numerical Distance Protection relay in
Kadra –Kaiga and Kodasalli –Kaiga.
KPCL
2. The PCSC forum requested KPCL to submit the
implementation status of PSAG-10 recommendations within
a week’s time.
34/I/6 400/220 kV
ICT-1 & 2 at
MUNIRABA
D
16-07-2014
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).
Mail recieved on 23-11-2015:
LOA's issued to M/s Schneider Electric Infrastructure Ltd. on 08.10.2015.
Engineering work is in progress.
KPTCL
2. Settings for main distance protection & Overcurrent
protection shall be examined and reviewed.
1. PCSC forum recommended KPTCL to replace the old
static distance protection relays with numerical relays.
KPTCL Mail recieved on 23-01-2016:
Detailed estimate prepared for taking up the work. CEE, Transmission Zone,
Gulbarga will take up necessary procurement and further execution.
KPTCL
Mail received on 27-05-2015 (KPTCL) & 29-07-2015:
2. PCSC forum also requested KPTCL to provide a broken
conductor alarm indication in Control Room.
1.Existing Back up relays will be replaced by numerical type distance
relays.Procurement is in tendering stage. Remaining observations were
attended.
3. Standing instruction needed to be given to the all
substation personnel for not changing the relay settings
without approval of RT/MRT wing.
KPTCL Mail recieved on 23-01-2016:
Existing back up relays will be replaced by Main-2 protection. LOI issued M/s
Alstom for taking up the works.Remaining observations were attended.
Page 3 of 18
Pending
Initial Tendering stage
4. Correct DR shall be submitted to the SRLDC for trip
analysis.
Fault had occurred in 220kV
Mahalingapura-Narendra line-2. Due to the
failure of relay operation at Mahalingapura,
breakers at remote end tripped which
resulted in bus dead condition.
Mail recieved on 27-05-2015 (KPTCL):
1. KPTCL has taken action to provide bus bar protection to 220kV buses.
2. Over current relay Settings of ICTs to be reviewed by PGCIL.
Mail received on 29-07-2015 (KPTCL):
3. Time synchronization of the Substation shall be
ensured.
38/G GD-1 at
25-10-2014
D/3.1 Mahalingapura
Substation of
KPTCL
Mail recieved on 21-10-2015:
Pending
NIT floated on 5.5.15 through e-portal. Bid evaluation completed. LOA's issued
to M/s Schneider Electric Infrastructure Ltd. on 08.10.2015.
Pending
Annexure-IV
38/G GD-1 at Guttur 05-11-2014
D/3.2 Substation of at 11:42 hrs
KPTCL
Circuit breaker of 400kV Guttur-Hiriyur
line-1 failed at Guttur end while availing
shutdown for replacement of CVT. The
failure of breaker caused bus fault at Guttur.
KPTCL was requested to expedite the early implementation KPTCL
of pending recommendations of:
1. Protection Audit (Phase-I & Phase-II)
2. PSAG-4, PSAG-5, and PSAG-8
39/I/5 Tripping of
400/220kV
ICT-2 at
Hoody
substation of
KPTCL
01-12-2014
40/I/1 GD-1 at 220kV 22-12-2014
Ambewadi
at 21:22 hrs
Station of
KPTCL
Suspected mal-operation of 220kV side
Rphase
over current relay
1. PCSC forum recommended KPTCL to replace the relay KPTCL
with a different make.
2. KPTCL was also requested to train the O&M personnel
adequately before performing any maintenance works to
avoid such unwanted trippings.
Triggering incident was B-phase to earth fault
in 220kV Ambewadi- Nagzari line-1. B-pole
of breaker did not open at Ambewadi end.
LBB protection not available at Ambewadi
end. All elements tripped on Zone-2 from
remote ends.
1. Till the completion of R&M works for bus bar and LBB KPTCL
protection, KPTCL shall explore the possibility of having
split bus operation at Ambewadi and submit the details of
the same to PCSC forum.
2. KPTCL shall provide the details of the tripping of Supa
hydro station connected downstream from 110 kV bus.
KPTCL mail received on 23-01-2016:
Pending
'The following works are attended at 400kV Guttur SS :
1. Replacement of Hiriyur-1 line, Bus Coupler, Tie Bus coupler breakers by new
Alstom make breakers (3 new CBs commissioned) recently.
2. New CVTs provided for 400kV Hiriyur line-1 and commissioned on
21.01.2016
Mail received on 27-05-2015 & 29-07-2015:
Pending
C&R panels of 500MVA ICT 1&2 will be replaced under scheduled R&M
works. O&M personnel are instructed to take sufficient care in order to avoid
unwarrented trippings.
KPTCL mail received on 23-01-2016:
New C&R panels(with numerical relays) erected for 500MVA ICT-1 &2 under
R&M work, which will be commissioned shortly.
Mail recieved on 29-07-2015:
Pending
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:
Bus-II PTs yet to be commissioned.Planned to complete before end of April2016.
40/IV/ 220kV Sedam- 20-12-2014
1
Tandur line
at 22:20 hrs
Line tripped on Yphase to earth fault from both KPTCL was requested to explore the possibility of
KPTCL
the ends
providing A/R feature to this line and submit the remedial
measures to the PCSC forum.
KPTCL mail recieved on 23-01-2016:
Carrier protection is being restored for 220kV Sedam-Tandoor line at Sedam
end. After restoring the carrier protection , AR will be enabled.
Pending
41/I/1 GD-1 at 220kV 16-02-2015
Kadra power at 12:56 hrs
Station of
KPCL
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.
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.
Pending
1. KPCL to make functional the Main2 (EPAC) relay
with the help of KPTCL at the earliest.
KPCL
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.
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.
3. KPCL to ensure supply for Main-1& Main-2
protections, Trip Coils (TC1, TC2) from separate battery
banks.
41/I/4 Complete
27-01-2015
outage at
at 8.00 hrs
220kV Sedam
Substation of
KPTCL (GD1)
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.
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 SedamTandur inter-state line.
Page 4 of 18
KPTCL
KPTCL mail received on 23-01-2016:
1. Bus bar protection panels pocured and erected at Sedam. Wiring , testing
,commissioning is being taken up.Planned to complete by April 2016.
2. Action is being taken to restore the carrier protection for 220kV SedamTandoor line. AR will be enabled after restoration of PLCC.
Pending
Annexure-IV
42/I/1 Complete
15-02-2015
(GD) outage of
at 14:24 hrs
220kV Sedam
substation of
KPTCL
Fault occurred in 220kV Sedam-Shahpur line
1. KPTCL to provide Bus Bar protection and LBB
protection at Sedam S/s and furnish
the status of their implementation to PCSC forum.
2. KPTCL to implement A/R feature on 220 kV SedamTandur inter-state line.
42/I/2 Complete
(GD) outage of
220kV
Ambewadi
substation of
KPTCL
Fault in 220kV Ambewadi-Nagjheri line-2
1. KPTCL shall provide A/R feature on Ambewadi – Ponda KPTCL
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.
12-03-2015
at 7:51 hrs
Page 5 of 18
KPTCL
Mail received on 29-07-2015:
1. Procurement of Bus bar and LBB protection is in the final tendering stage.
2. Action is being taken to restore the carrier protection for 220kV SedamTandoor line. AR will be enabled after restoration of PLCC.
Pending
Mail received on 29-07-2015:
Pending
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 SedamTandoor line. AR will be enabled after restoration of PLCC.
Annexure-IV
42/II/2 Tripping of
20-02-2015
220kV
at
Chikodi06:40 hrs
Talandage and
220kV ChikodiMudshingi line
Lines tripped during test charging 220kV
Chikodi-Belgaum line-2 from Chikodi
end.
1. KPTCL to provide A/R feature on the 220 kV Chikkodi – KPTCL
Talandage, and 220 kV Chikkodi –Mudashinge inter-state
lines.
2. KPTCL to carry out E/F relay coordination for Chikkodi Talandage and Chikkodi –
Mudashinge lines in coordination with Maharashtra.
KPTCL mail received on 23-01-2016:
Pending
1) Replaced existing VXL by ABB make C&R panel for both interstate lines on
21.04.2015. The ABB Engineer visited 220KV Chikodi on 05.11.2015 for
enabling AR system to existing ABB make REL511 relay for both interstate
line, but AR system not enable due to internal cards faulty. Hence action is being
taken to replace the ABB,REL511 distance relays within a months time.
43/II/1 Tripping of
4
400/220kV
ICT-1 at
BTPS
ICT tripped due to operation of Over current
and Earth fault relay
KPCL to check the possibility of providing line differential
protection between RTPS and Yermarus stations.
KPCL
Mail received on 07-09-2015 , 21-10-2015 and 23-11-2015:
Pending
Revised relay settings are awaited from KPTCL.
Revised relay settings furnished by KPTCL will be incorporated in co-ordination
with KPTCL shortly.
KPCL
Mail received on 07.07.2015:
The matter had been discussed with KPTCL. KPTCL recommended to keep
Zone-2 time lever to zero. If this is acceptable, then the same shall be
incorporated immediately.
14-01-2015
at 1:09
hrs
44/II/3 Tripping of
22-04-2015
220kV
at
Kaiga20:28 hrs
Kodasalli
and 220kV
KodasalliNagjheri line- 1
220kV Kodasalli-Nagjheri line-1 tripped from 1. KPCL to check the possibility of implementing
Kodasalli end on operation of
Permissive Over Reach (POR) with Echo feature at
distance protection, zone-2.
Kodasally end.
45/III/ Tripping of
01-06-2015
12
400kV Raichur- at 01:02 hrs
BTPS line
line tripped on R-phase to earth fault. Line did KPCL to make A/R operational on 400 kV RTPS – BTPS
not auto-reclose
S/C line at both ends.
46/II/2 Trippings at
07-06-2015
1
220kV Raichur at 01:35 hrs
TPS
220kV Kodasalli-Nagjheri line-1&2 is kept
opened from Nagjheri end, hence fault
could not be cleared with carrier aided
protection. Backup earth fault relay at
Kaiga end got operated during the event and
resulted in tripping of 220kV KaigaKodasalli line from Kaiga end.
2. If the above is not possible, KPCL shall check the
possibility of keeping the 220kV
Kodasalli-Nagjheri lines OPEN at Kodasalli end and idlecharged at Nagjheri end, and
implement the same.
1. KPCL to check the operation of anti-pumping relay on
220 kV side and keep it in healthy condition.
2. KPCL to provide manual reset to the 220 kV side master
trip relay.
3. KPCL to use both the 220 kV buses as main buses under
normal operation, and should go for single bus operation
only during emergencies.
Page 6 of 18
Pending
Mail received on 07-09-2015 , 21-10-2015 and 23-11-2015:
The matter has been discussed with KPTCL. KPTCL recommended to keep
Zone-2 time lever to zero.
If this is acceptable to SRLDC, then the same shall be incorporated
immediately.Reply from SRLDC is awaited.
KPCL
Mail recieved on 23-11-2015:
Completed at RTPS end.
Pending at
BTPS end.
KPCL
Mail recieved on 23-11-2015:
Pending
1) Completed
2) 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.
Annexure-IV
47/II/1 Tripping of
3
Unit-1&2
along with
400/220kV
ICT-2 at
Raichur TPS
06-08-2015
at 4:51 hrs
220kV RTPS-Lingasugur line-2 tripped at
TPS end on operation of distance
protection zone-1. 400/220kV ICT-2 got
tripped on operation of earth fault
protection. 220kV RTPS-Lingasugur line1&3 tripped on distance protection
zone-2 and zone-3 respectively. Due to
tripping of ICT-2, the running units got
overloaded and it was mentioned that
under frequency occurred as units are
on load control. The Units got tripped
on under frequency.
KPTCL to activate non-directional Over Current protection
with a time delay of 600-800 msec for Fuse
failure condition at Lingasugur.
KPTCL
Yet to be informed
Pending
47/III/ Tripping of
8
220kV
AmbewadiPonda line-2
02-08-2015
at 13:20 hrs
Line tripped on a transient fault in B-phase.
There is no
provision for auto reclose.
Till A/R is put into service on Ambewadi-Ponda line-1,
KPTCL to reduce Zone-2 time setting to zero sec. at
Ambewadi end.
KPTCL
Yet to be informed
Pending
47/III/ Tripping of
10
220kV
AmbewadiPonda line-1
08-08-2015 Line tripped on a B-phase to earth fault. Line
at 10:51
tripped as there is no provision for auto-reclose
hrs and 09-082015 at
11:15 hrs
47/III/ Tripping of
12
220kV
AmbewadiPonda line-1
17-08-2015
at 13:20 hrs
KPTCL to revise distance relay settings at Nelamangala
KPTCL
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.
Yet to be informed
Pending
48/I/2 Complete
27-09-2015
(GD) outage of
at 4:23:17 hrs
220kV Peenya
Substation in
Karnataka
Line tripped on a transient fault . There is no
provision for Auto reclose.
All 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.
Page 7 of 18
Annexure-IV
48/I/3 Outage of
(GD) 220kV
Ambewadi
station in
Karnataka
30-09-2015
at 10:41 hrs
220kV Ambewadi-Nagjheri line-2 tripped on B- KPTCL to fast-track providing A/R on all 220 kV lines
KPTCL
phase to earth fault. This resulted in loss of
emanating from Ambewadi SS to prevent Station shut-down
supply to 220kV Ambewadi bus. 220kV
on temporary faults.
Ambewadi-Ponda line-1&2 were hand tripped
after deenergization of bus at Ambewadi.
KPTCL mail received on 23-01-2016:
Will be complied in a months time.
Pending
48/I/4 Complete
(GD) outage of 220
kV HSR
substation of
Karnataka
06-10-2015
at 16:32 hrs
All connected 220kV lines at 220kV HSR
substation i.e. Somanahalli, EPIP, Hoody and
Nagnathapura tripped during the incident.
Triggering incident was fault in 220kV HSREPIP line
KPTCL mail received on 23-01-2016:
ABB make REL 670 type distance relays provided to Somanahalli and hoody
lines. Planned to commission within 10 days.
Pending
49/I/1. Complete
3
outage of
(GD) 220kV
Ambewadi
Substation of
KPTCL
29.10.2015 at 220kV Nagjheri-Ambewadi line-1 tripped at
14:34 hrs
13:33 hrs due to B phase to earth fault.
Ambewadi was radially fed from Nagjheri
power station through 220kV NagjheriAmbewadi 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 KPTCL
Nagjheri PH.
Yet to be informed
Pending
49/II/1 Trippings at
5
Raichur TPS
12-11-2015
at 00:30 hrs
1. KPCL to carry out hot-line washing of RTPS-connected
lines regularly to avoid trippings due to fog and dust.
Yet to be informed
Pending
Running Unit-4, 5 and Unit-8 and 400kV
RTPS-Yeramaras TPS feeder got tripped due
to de-energization of both 400kV Bus-1&2 at
Raichur TPS
KPTCL to review distance relay settings at Naganathpura
SS in view of LILO arrangement at HSR Lay-out.
KPTCL
2. KPTCL to provide A/R on all 220 kV lines emanating
from Ambewadi SS.
KPCL
2. KPCL may see the feasibility of providing breaker
flashover protection at RTPS, and implement the same if
possible.
Tamil Nadu
43/II/5 Tripping of
29-03-2015
400kV
at
Alamathy15:29 hrs
SVChatram
line-1&2
and 400/230kV
ICT
at S.V.Chatram
Line-2 tripped on R-phase to earth fault.
TANTRANSCO was requested to swap the relays between TANTRANS TANTRANSCO vide their mail dated 24.06.15 informed that different relays in Pending
Line autoreclosed at SVChatram end and failed two stations, so that
CO
Main-I & Main-II would be ensured at the earliest.
to reclose at Alamathy end. Bphase to earth
Main-1 and Main-2 will be of different make at each station.
fault in line-1. Line tried for A/r but due to
Mail recieved on 24-07-2015:
permanent fault line did not reclose. ICT
Different relays in Main-I & Main-II will be ensured.
tripped on operation of over flux protection.
48/I/1 Disturbance in 05-09-2015
(GD) 220kV
at 14:04 hrs
Tamilnadu
system
Complete outage of 230kV Palladam, 230 kV
Othakalmandapam S/s, 230 kV Coimbatore
S/s, 230 kV Thudialur and 230 kV
Sadayapalayam S/s
48/II/6 Tripping of
07-09-2015
400/220kV
at 04:24hrs
Alamathy ICT3,4&5
Triggering incident was failure of Y & B phase 1. TANTRANSCO to furnish a detailed report on the
CT failure in 230kV Korattur feeder
tripping event covering the sequence of events, and the
remedial measures taken to PCSC forum.
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.
2. TANTRANSCO to configure Bus-Bar protection at
Alamathy for instantaneous operation.
Page 8 of 18
TANTRANS Yet to be informed
CO
Pending
TANTRANS Yet to be informed
CO
Pending
Annexure-IV
49/I/1. Complete
09-11-2015at Fault had occurred in 230kV MAPS-S.P.Koil
5
outage of
09:33 hrs
feeder-1. LBB protection got operated as
(GD) S.P.Koil
breaker of this feeder was under lockout and
station of
resulted in tripping of 230kV bus at S.P.Koil.
TANTRANSC
Unit-1&2 at MAPS due to loss of evacuating
O and
feeders i.e. 230kV MAPS-S.P.Koil feeder-1&2
generation loss
at MAPS
1. TANTRANSCO to ensure correctness of operation of
LBB relays at SP Koil.
2. TANTRANSCO & MAPS to furnish their respective
compliance report of the recommendations of to-beconducted PSAG-14 meeting at MAPS, Kalapakkam.
TANTRANS Yet to be informed
CO
Pending
50/I/3 Complete
21-12-2015
(GD) outage of
at 6:28 hrs
230kV
Mywadi station
of
TANTRANSC
O
Busbar protection got operated for a fault in
230kV Mywadi-Anaikadavu line
1. TANTRANSCO to examine the feasibility of providing TANTRANS Yet to be informed
two main-zone operation for bus bar protection by exploring CO
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.
Pending
50/II/2 Tripping of
400kV
AlamathyS.V.Chatram
line-2
Line tripped on D.T. receive on CHANNEL-2 TANTRANSCO to provide A/R for 400 kV bay Tie-CB’s TANTRANS Yet to be informed
at SV.Chatram end when the operator at
at Alamathy SS and SV Chatram SS.
CO
ALAMATHY S/S end tried to close AlamathySVChatram-1&2 Feeder Tie Breaker.
Suspected DC earth fault had caused the
initiation of direct trip.
Pending
08-11-2015
at 10:48 hrs
Page 9 of 18
Annexure-IV
50/II/1 Tripping of
6
400kV
AlamathyS.V.Chatram
lines - 1&2
27-11-2015
at 15:35 hrs
50/II/1 Tripping of
27-11-2015
7
400/230kV
at 17:26 hrs
Myvadi ICT-3
400KV Aalmathy-S.V.Chatram line-1 tripped
TANTRANSCO to check and ensure the healthiness of
on B-phase to earth fault. Line auto reclosed
A/R scheme at Alamathy end on 400 kV Alamathy – SV
and at both end subsequently A/R locked out Chatram line – 2.
due to permanent fault.
400KV Alamathy-S.V.Chatram line-2 Line
tripped on R-phase to earth fault. Line
autoreclosed at S.V.Chatram and failed to autoreclose at S.V.Chatram end.
TANTRANS Yet to be informed
CO
Pending
400/230kV Myvadi ICT-3 tripped due to the
TANTRANSCO to check the LBB scheme for LV-3, and
operation of 230 kV CB LBB protection at 230 furnish the remedial measures taken to PCSC forum.
KV bus (TNEB) of Myvadi station.
TANTRANS Yet to be informed
CO
Pending
KSEB
Mail recieved on 30-10-2015:
1. Purchase procedures is still in progress.
2. Replaced.
3. PLCC equipment Tested and found OK.
Pending
(Recomme
ndation
No.1)
KSEB
Yet to be informed
Pending
Yet to be informed
Pending
Reply received during 46th PCSC meeting:
Pending
Kerala
44/I/1 Complete
(GD) outage of
Idukki Hydro
Power Station
(GD-1)
28-04-2015 220 kV breaker of unit-3 at Idukki Power
at 12:30 Hrs house flashed and bus differential protection
acted. All Generators (6Nos.) along with all
220 kV feeders tripped during the incident.
1. 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 Pallam and
inform the remedial measures taken to PCSC forum.
49/II/3 Tripping of
12-10-2015
220kV
at 21:30 hrs
EdamonTirunelveli line1&2
220kV Edamon-Tirunelveli lines -1&2 got
KSEB to furnish reasons for DT not being sent to the
tripped due to operation of Bus Bar protection remote end during the tripping event along with remedial
which was due to human error
measures taken to PCSC forum.
49/III/ Tripping of
1
220kV
SabarigiriTheni line
Line tripped on a R-phase to earth fault. At
Sabarigiri, relay gave a 3 phase trip after
220ms. From Theni end D.R, auto reclose
block was observed.
KSEB to furnish a report on the tripping incident along with KSEB
the remedial measures taken to PCSC forum.
As reported pole-2 tripped due on 5th
harmonic alarm.
1. Complete analysis of the faults and rectification/remedial PGCIL
action taken to avert similar occurrence in the HVDC Back
to Back station shall be submitted.
2. The PCSC forum recommended PGCIL, SRTS-I take up
the issue with WRTS to submit the report as per IEGC
guidelines.
3. SRLDC is also requested to send a letter to WRLDC to
submit the reports to SR also.
4. Based on the SRTS/SRLDC correspondences, SRPC
would take it up with WR and PGCIL if the issue is not
getting resolved.
09-10-2015
at 16:56 hrs
PGCIL
34/I/7 HVDC
18-07-2014
BHADRAVA
THI POLE 2
Page 10 of 18
Being pursued with POWERGRID, WR-1
Annexure-IV
42/II/7 Tripping of
23-02-2015
400kV
at
Jeypore13:34 hrs
Gazuwaka line1&2 and
tripping of
HVDC back to
back pole1&2 at
Gazuwaka
HVDC pole-1 got tripped due to failure
of 4 no. power supply card. HVDC
pole-2 tripped on DC low voltage trip.
400kV Jeypore-Gazuwaka line-1&2
tripped due to operation of Over voltage
protection at Gazuwaka end.
PGCIL (SR-II) to submit the report of M/s ABB’s on
preventing supply card failures.
42/II/2 Tripping of
14-03-2015
2
HVDC pole- at
1&2
17:12 hrs
at Gazuwaka
and
400kV 400kV
Jeypore
Gajuwaka
line -1
HVDC Pole-1 at Gazuwaka tripped due to
tripping of filter banks and Pole-2 tripped
due to operation of differential protection.
400kV Jeypore-Gazuwaka line-1 tripped
on over-voltage from Gazuwaka end.
42/II/2 Tripping of
3
HVDC
Bhadravathi
Pole-1
18-03-2015
at
13:55 hrs
Pole tripped due to failure of auxiliary supply
43/II/2 Multiple
tripping
at 400/230kV
Hosur
substation
of Powergrid
26-03-2015
at 15:40 hrs
44/I/3 765 kV
24-05-2015
(GD) Raichurat 19:19 hrs
Sholapur line 1
&
2 tripped
Yet to be informed
Pending
PGCIL (SR-I) to furnish the reasons for Converter
PGCIL
Transformer differential protection
operation for Pole-2 along with the remedial measures taken.
Reply received during 46th PCSC meeting:
Pending
PGCIL (SR-I) to submit the compliance report on PSAG-11 PGCIL
recommendations to PCSC
forum.
Reply received during 46th PCSC meeting:
230kV Bus-2 at Hosur (PG) got
tripped as spurious initiation got
extended to LBB relay of 230kV
Hosur-Hosur(PG) line at Hosur(PG)
end due to shorting of contacts in
lockout relay. 400/230kV ICT-2, ICT3, 230kV Hosur-Vinnamangalam,
230kV Hosur(PG)-Hosur which were
connected to Bus-2 got tripped along
with bus coupler breaker
PGCIL (SR-II) to check the possibility of providing re-trip
feature in LBB relay.
Mail received on 02-09-2015:
The scheme was tested thoroughly found normal.
Pending to
check the
possibility
of re-trip
feature
Tripped on Overload.
1. PGCIL to provide the status of healthiness of SPS contact PGCIL
logic in SRLDC’s SCADA.
Yet to be informed
Pending
2. PGCIL to furnish the details of the implemented SPS-7
scheme including logic diagram to PCSC forum.
Page 11 of 18
PGCIL
PGCIL
Operation is in-order as per OEM manual (ABB HVDC)
Pending
Tertiary Transformer charged and auxiliary power for HVDC is being availed
from tertiary widings of ICT.
Annexure-IV
44/II/4 Tripping of
23-04-2015
400kV
at
Ramagundam- 15:11 hrs
Hyderabad line3,
400kV
HyderabadMalkaram line1 and 400kV
Bus-1
at Hyderabad
400kV Ramagundam-Hyderabad line-3 at
ramagundam end only due to DT receive.
400kV Hyderabad-Malkaram line-1
tripped at Hyderbad end only and was
holding from Malkaram end. 400kV Bus-1 at
Hyderabad due to operation of bus
bar protection.
PGCIL (SR-I) to check healthiness of PLCC panels at
Hyderabad SS, and repair/ replace
them, if necessary.
PGCIL
Yet to be informed
Pending
44/II/6 Multiple
25-04-2015
tripping at
at 10:04
Vemagiri
hrs
substation of
APTRANSCO
400kV Vemagiri-Vijayawada line-1&3, 400kV
Vemagiri-Goutami line-2, 400kV VemagiriKonaseema line-2 and 400/220kV ICT-2 at
Vemagiri tripped
during the incident. Triggering incident
was failure of B-phase L.A in 400kV
Vijayawada-Vemagiri line-1 at Vemagiri.
1. PGCIL (SR-I) to enable Auto reclosure feature at
Vijayawada end.
PGCIL
Yet to be informed
Pending
44/II/7 Tripping of
25-04-2015
765kV
at
Kurnool18:10 hrs
Tiruvalam line1
and 765kV
KurnoolNPS-1
REF protection of Line reactor of
1. PGCIL (SR-I) to submit the action taken report on the
Nellore-1&2 and Tiruvalam line-1 maloperated measures suggested by their OEM.
due to DC earth fault
2. PGCIL (SR-I) to check for the availability of Chatter
Disable feature in P141 and
configure it appropriately to block operation of REF
protection on DC fluctuations.
PGCIL
Yet to be informed
Pending
44/II/8 Tripping of
400kV
Gooty-NPS
line-2
R-phase to earth fault had occurred in
line. Lines auto-reclosed at gooty end
and later tripped due to DT receive from
NPS end.
PGCIL (SR-I) to coordinate STUB protection settings with
the distance protection time
settings at NPS.
PGCIL
Yet to be informed
Pending
45/II/1 Tripping of
03-05-2015
5
765kV Raichur- at 4:13 hrs
Solapur line1&2
Lines tripped on transient fault. Auto reclose
was un-successful. SR &NEW grid separated
due to tripping of 765kV lines
To avoid tripping of transmission lines on transient faults,
PGCIL 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).
PGCIL
Yet to be informed
Pending
45/II/2 Tripping of
03-06-2015
1
400/220kV
at 12:30 hrs
ICT-1 at Gooty
Substation
ICT tripped due to mal-operation of
differential relay
1. PGCIL to follow IS and CEA regulations while carrying
out maintenance work.
PGCIL
Yet to be informed
Pending
26-04-2015
at 13:16
hrs
2. PGCIL (SR-I) to check distance relay settings for
Vijayawada – Vemagiri line 3, and
furnish a compliance report to PCSC forum.
2. PGCIL to furnish a report on what caused the ICT-1
tripping including remedial measures.
Page 12 of 18
Annexure-IV
46/II/1 Tripping of
16-06-2015 ICT-2 tripped due to mal-operation of 86B
400/220kV
at 18:12 hrs& relay due to suspected DC earth fault.
ICT-2 at
19:18 hrs
Nagarjunsagar
Station
PGCIL (SR-I) to furnish a detailed report on ICT-2& Bus II PGCIL
outage at 19.18 hrs on 16.06.2015 along with the remedial
measures taken.
Yet to be informed
Pending
46/II/4 Tripping of
22-06-2015
400/220kV
at 13:06 hrs
ICT-2 at Gooty
substation
At 220kV Gooty Switching Station, 220KV
Gooty Receiving Station feeder line side YPhase jumper connected between line isolator
to boom resulting in a 220kV Bus fault. This
resulted in tripping of ICT-2 and 220kV
feeders connected to 220KV BUS-II.
PGCIL (SR-I) to furnish a detailed report as to what caused PGCIL
LBB operation at 400 kV Gooty SS along with the remedial
measures taken.
Yet to be informed
Pending
46/II/1 Tripping of
01-07-2015
3
400kV Gooty- at 09:59 hrs
NPS line-1
Breaker at NPS end tripped on Direct Trip
receipt from NPS end. After 4 seconds, over
voltage protection operated at NPS end as
observed from EL, and direct trip was sent to
Gooty.
1. PGCIL (SR-I) to furnish a report detailing the sequence of PGCIL
events including the remedial measures taken to PCSC
forum.
Yet to be informed
Pending
Yet to be informed
Pending
2. PGCIL (SR-I) to verify and ensure time-synchronizationof
DR& EL with GPS at both Gooty and NPS.
3. PGCIL (SR-I) to check and resolve,in co-ordination with
APTRANSCO, the professed Phase-Discrepancy that is
found to be occurring between 400 kV Gooty (PG) SS and
the surrounding 220 kV network of APTRANSCO in the
event of a fault.
46/II/2 Separation of
2
SR-grid and
NEW-grid
28-07-2015
at 11.52.22
hrs.
1. PGCIL (SR-I) to obtain from PGCIL (WR-l) the reasons PGCIL
for DT receipt from Sholapur end and furnish thesame along
with the remedial measures taken to PCSC forum.
2. PGClL (SR-I) to verify the logic implemented of SPS-1
and SPS-7 for the 76S kV Raichur - Sholapur link
byavailing the line shutdown at the earliest opportune time.
3. PGCIL (SR-I) to furnishthe details of the implemented
SPS-1 and SPS-7 schemes including their logicdiagrams to
PCSC forum.
47/II/1 Tripping of
1
HVDC
Bhadrawati
Pole-1
05-08-2015
at 10:53 hrs
47/II/1 765 kV
04-09-2015
8
RAICHUR at
SHOLAPUR 1 19:25 hrs
and 2
Main pump-2 of valve cooling got
tripped during dip in 33kV auxiliary bus
voltage. Valve cooling flow got reduced
due to tripping of pump and resulting in
tripping of pole-1
PGCIL (SR-I) to furnish compliance report on PSAG-11
recommendations without further delay to PCSC
forum.
PGCIL
Yet to be informed
Pending
Sholapur -1 and 2 Feeder got tripped at
Raichur end on operation of over current
protection in Main-1 distance relay and
holding from Solapur end on 04.09.2015 at
19:24:42 Hrs
1. PGCIL (SR-I) to check the A/R scheme implemented
through BCU’s at all its GIS/ SAS substations for correct
operation.
2. PGCIL (SR-I) to ensure time-synchronization of DR &
EL of 765 kV Kurnool SS with GPS.
3. PGCIL (SR-I) to sort out the LEGEND ISSUE related to
tripping of the lines in the Event Logger of Raichur.
4. PGCIL (SR-I) to check & ensure the functionality &
healthiness of synchronization facility at Raichur end at the
earliest opportune time.
PGCIL
Yet to be informed
Pending
Page 13 of 18
47/II/1
8
765 KV
04-09-2015
RAICHUR – at
KURNOOL 2 19:25 hrs
Kurnool -II Feeder got tripped on B-N fault
and holding from Kurnool end (successfully
auto-reclosed at Kurnool end) subsequently
tripped at other end on operation of Over
Voltage stg-1 protection at Raichur end on
04.09.2015 at 19:24 Hrs
1. PGCIL (SR-I) to check the A/R scheme implemented
through BCU’s at all its GIS/ SAS substations for correct
operation.
2. PGCIL (SR-I) to ensure time-synchronization of DR &
EL of 765 kV Kurnool SS with GPS.
3. PGCIL (SR-I) to sort out the LEGEND ISSUE related to
tripping of the lines in the Event Logger of Raichur.
4. PGCIL (SR-I) to check & ensure the functionality &
healthiness of synchronization facility at Raichur end at the
earliest opportune time.
PGCIL
Yet to be informed
Pending
Annexure-IV
49/II/4 Tripping of
13-10-2015at Direct Trip was sent to NPS end of line-1
1. PGCIL (SR-I) to configure time scale resolution in Event PGCIL
400kV Gooty- 10:15 hrs
during opening of Main CB of Gooty-NPS line- Logger to msec. at Nelllore PS (NPS) and furnish DR
NPS line-1
2 at Gooty end. This resulted in tripping of line- corresponding to OVR, Stag-I operation at NPS end during
1 at NPS and line was holding from Gooty.
the tripping event.
Over voltage protection got operated at NPS
end and resulted in tripping of line
2. PGCIL (SR-I) to ensure time-sync of DR’s and EL’s with
GPS at Gooty and NPS.
Yet to be informed
Pending
50/I/2 Complete
(GD) outage of
TPCIL power
station
Yet to be informed
Pending
30-12-2015
at 06:02hrs
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)-ECC line
1.PGCIL (SR-I) to furnish Action Taken Report on the
PGCIL
findings of OEM on relay mal-operation at NPS end on 400
kV NPS – NCCK 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.
Others
41/II/1 Tripping of
13-02-2015
2
400KV Coastal- at 22:54 hrs
NTPL line
Line tripped B-phase to earth fault and later
 CEPL to check A/R scheme at their end.
tripped on R-Y phase fault. From Coastal end
D.R, Y & B poles of breaker opened first and
R-pole appears to be opened on Pole
discrepancy.
CEPL
Yet to be informed
Pending
41/IV/ 400kV
2
Tuticorin PSNTPL line
09-02-2015
at 03:17 hrs
Y-phase to earth fault had occurred in line.
Line auto reclosed at Tuticorin PS end and
failed to reclose at NTPL end.
NTPL to check A/R scheme at their end.
NTPL
Yet to be informed
Pending
44/III/ Tripping of
4
400kV
Coastal
(CEPL)Tuticorin
pooling
station
20-04-2015
at 12:35 hrs
Line tripped at Coastal energen end only and
was holding from TTRNPS
CEPL to furnish a detailed report on this trip event to PCSC CEPL
forum.
Yet to be informed
Pending
Line tripped on operation of overvoltage
protection at Ramagundam end and direct trip
was received at Dichipalli. Over-voltage
operation could not be established with D.R &
E.L submitted by Ramagundam station.
1. NTPC, Ramagundam to investigate the reasons for Over NTPC
Voltage alongside checking the drop off- to- pick-up ratio of
the OV relay.
2. The tripping is not as per the grading adopted for
Overvoltage, Stage-I protection (Grading is C2: 110% and 6
sec time delay) at Ramagundam. NTPC, Ramagundam to
check up the same.
Yet to be informed
Pending
46/II/3 Tripping of
21-06-2015
400kV
at 03:27 hrs
RamagundamDichipalli line
Page 14 of 18
Annexure-IV
47/III/ Tripping of
2
400kV
Vemagiri –
GVK (JPD)
line-2
16-07-2015
at 17:02 hrs
R-phase to earth fault had occurred in line.
Line auto reclosed at Vemagiri end and failed
to reclose at GVK end.
GVK to put A/R into service at GVK Jegurupadu end on
400 kV GVK (Jegurupadu) – Vemagiri line-2.
GVK
Yet to be informed
Pending
48/II/1 Tripping of
05-10-2015
6
400 kV Hassan at 13:33
-Udupi line-1
Line tripped due to B-E fault in Z2. Main 1
UPCL to furnish reasons for delayed operation of distance UPCL
relay tripped in Z2. Three phase trip operated relay in Zone-1 at their end, and the remedial measures
at Hassan. Auto-reclose successful at other end taken, if any.
and line was charging from other end. Then
OV stage 1 picked up in Main2 relay and
operated in OV after the time delay
Mail recieved on 19-11-2015 (UPCL):
Pending
The fault was of resistive nature, was sensed from Hassan end in Zone-2 reach.
The DR from UPCL indicates resistive high current prior to operation of Zone-1
in C Phase. This is seen as development of Zero sequence voltage and current
prior to Zone -1 operation.
The operation of single phase Z1 from UPCL end was correct followed by
successful AR operation.
50/II/1 Tripping of
30-11-2015
8
400kV UPCL- at 17:22 hrs
Hassan line-2
and running
Units-1&2 at
Udupi power
station
400kV Hassan-Udupi line-2 tripped on
Directional earth fault protection with Y-E
fault and direct trip was sent to Udupi end.
Directional Earth fault feature of Main-2 relay
at Hassan gave 3-ph trip after 2.6 seconds and
fault current in Y-phase was 1.1 kA. The
distance as well as DEF protection for 400kV
UPCL-Hassan line-2 at UPCL end did not
sense the fault. The generator transformer
backup earth fault protection (51N) had sensed
the fault and tripped both the running units at
UPCL leading to generation loss at UPCL
power station. Back up directional earth fault
protection at 220kV side of 400/220kV ICT’s
at UPCL did not sense the high resistance fault
in line-2
Yet to be informed
1. UPCL to provide different make relays for Main-1 &
UPCL
Main-2 at UPCL end on 400 kV UPCL – Hassan lines – 1 &
2.
2. UPCL to make GPS functional at their Station and ensure
time-sync of various DR’s and EL’s with GPS.
Page 15 of 18
Pending
Annexure-IV
Miscellaneous
36/II/8 400kV
07-09-2014
RaichurMunirabad line
B-phase to earth fault had occurred in line.
KPTCL:
Line auto reclosed at Munirabad end and failed PD (pole discrepancy) time delay would be changed.
to reclose at Raichur end.
38/II/5 400kV
27-10-2014
RamagundamHyderabad line4
 Line tripped on Bphase
to earth fault.
 Line did not auto
reclose at Hyderabad
end due to
PLCCmal-operation.
39/I/2 Tripping of
400Kv
GhanapurMamidipally
line
22-12-14
Due to PLCC Mal-operation at HYD S/S end,
at 10:52 hrs, DT received at MMPLY end and line got
24-12-14 at tripped.
11:32
hrs,
24-12-14 at
16:16 hrs
PGCIL /
KPTCL
Planned to replace the PLCC system within a week's time at NTPC/
both the ends during the shutdown.
PGCIL
PGCIL is requested check up with the manufacturer to
resolve the issue and submit remedial measures to PCSC
forum.
Yet to be informed
Pending
Yet to be informed.
Pending
PGCIL/
Mail received on 26-05-2015 from TSTRANSCO:
Pending
TSTRANSCO
On 27-12-2014 PGCIL requested to arrange services of OEM(Manufacturer)for
identifying the problem. TSTRANSCO arranged the same on 06-01-2015 and
the manufacturer testing and concluded that the problem in not in the newly
erected digital protection coupler at both ends and the issue is related to relay
panel at Ghanapur. [OEM minutes enclosed]
40/II/3 Tripping of
01-01-2015
400
at
kV
13:38 hrs
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
PGCIL/
phase discrepancy in the relay operation and take suitable KPTCL
remedial measures.
42/II/1 Tripping of
19-02-2015
400kV Coastal- at
Tuticorin PS
16:37 hrs
line
Line tripped at Coastal end only
due to suspected PLCC maloperation
and was holding from
Tuticorin PS end. Running Unit at
Coastal energen also got tripped
during the event.
PLCC end-to-end testing shall be carried out by CEPL and
Tuticorin PS (PGCIL-SR II) by
06.04.2015.
42/II/1 Multiple
8
tripping at
Raichur
thermal
power station
of
KPCL
400kV Raichur TPS-Raichur(PG) line1&2, 400kV Raichur-Mahboobnagar,
Unit#7 and ICT-2 at RTPS tripped
during the incident. B phase to earth
fault had occurred in 400kV Raichur
TPS-Raichur line-1
1. KPCL to review REF setting (DMT or IDMTL) for unit-7 KPCL/TSTR Mail received on 26-05-2015 from TSTRANSCO:
Pending
by first week of April, 2015 and
ANSCO/PGC
It is found that the main-2 ABB make REL316 type distance relay was
inform the same to PCSC forum.
IL (SR-I)
defective and same was replaced with MICOM P444 by M/s.PGCIL on 23.042. TSTRANSCO to furnish Mehaboobnagar’s DR and EL
2015. After replacement of main-II, DR can be extracted from this relay. For EL
and the reasons for distance relay
in to service, some field winding is pending which is being taken up in this
operation at their end within a week’s time.
month.
09-03-2015
at
06:36 hrs
2. KPTCL to check the PLCC operation at Talaguppa
end and submit the report to the PCSC forum.
3. PGCIL (SR-I) to rectify the issues relating to A/R
operation, relay reach (Z2), reverse reach
(Z4) and SOTF auxiliary contacts within a week’s time, and
submit the actions taken to
PCSC forum.
Page 16 of 18
Mail received on 27-05-2015 (KPTCL) & 29-07-2015:
End to end testing of PLCC has been done and problem in the PLCC is
atttended. Phase discripancy in the relay operation is to be checked jointly.
Mail recieved on 02-09-2015:
Problem is in identification of phases at Talguppa end. To be rectified by M/s
KPTCL.
CEPL/
Mail received on 02-09-2015 and 25-11-2015:
PGCIL(SR-II) On 11.06.2015 PLCC testing carried out by M/s ABB Engineer. ABB suspects
that the problem is with frequency interference related issue, and suggested to
change to new frequecies.
Pending
Pending
with CEPL
Annexure-IV
43/II/1 Multiple
2
tripping at
400kV
Raichur(PG)
and RTPS of
KPCL
11-04-2015at 400kV Raichur(PG)-Gooty line-2,
18:04 hrs
400kV Raichur TPS-Raichur(PG)
line-1&2, 400kV RaichurMahboobnagar, Unit#5 at RTPS
tripped during the incident
KPCL, KPTCL and PGCIL (SR-I) to furnish the action
KPCL/KPTC Yet to be informed
taken report on the
L/ PGCIL(SRrecommendations given by PSAG members held at Raichur I)
on 22-04-2015 and
23-04-2015.
Pending
44/I/3 Tripping of
(GD) Unit 1 at
NCTPS
24-05-2015
at 19:13 hrs
ID Fan trip
1. All Tripped units, viz., Krishnapatinam, MEPL, Raichur,
NCTPS to submit a detailed report
on this event including the remedial measures taken to PCSC
forum.
Tripping of
Unit 1 at
MEPL
24-05-2015
at 19:13 hrs
Coal Mill tripped
Pending
with
KPCL,
APGENC
O
Tripping of
24-05-2015
Unit 1 at
at 19:17 hrs
Krishnapatnam
Generator Protection operated
Tripping of
24-05-2015
Unit-8 at RTPS at 19:19 hrs
Tripped on Overvoltage.
45/I/2 Complete
(GD) outage of
MEPL power
station
20-05-2015
at 20:38 hrs
47/I/2 Complete
08-09-2015
(GD) outage of
at 18:20 hrs
Krishnapatnam
TPS
Y phase CT failure at MEPL led to tripping of
400kV NPS-MEPL, 400kV SEPL-MEPL line
and Unit-2 at MEPL. Uni-1 was not in service
at the time of tripping
2. KPCL to check the excitation system of Unit 8 of RTPS,
and submit the remedial measures
taken to PCSC forum.
1. MEPL to ensure healthiness of all CT’s by carrying out
Tan Delta and DGA tests wherever necessary.
2. MEPL to take suitable action to correct the operation of
tie-CB Bay Control Unit that caused LBB/ BBP operation.
3. PGCIL (SR-1) to carry out end-to-end PLCC testing in
coordination with MEPL and ensure that carrier-aided
protection on MEPL – NPS line is in healthy condition.
4. SEL to properly time-coordinate their Over Current
phase and Earth fault relays in consultation with MEPL.
KPCL/
MEPL/
APGENCO/
TNEB
TANGEDCO vide their mail dated 07.07.2015 informed that as per the
discussion and recommendation of 44th meeting of PCSC held on 28.05.2015, a
time delay of 2 Sec had been introduced for the above tripping for all the ID
fans at NCTPS-II.
MEPL vide their mail dated 14.09.2015 informed that they have implemented 2
seconds delay for under voltage tripping of all Drag Chain Feeder Conveyors.
And this has been done for both the Units.
MEPL/
MEPL vide their mail dated 14.09.2015: informed the following
PGCIL(SR-I)/ 1. Tan Delta Testing of winding and DGA of Insulating Oil for all CTs was
SEL
carried out and normal.
2. Could not find any problem during internal checks hence we are in touch with
ABB for rectification work. Will be done by the end of 15th Oct'15
3. End to end testing of Carrier signals was carried out and found them healthy.
As per FIR submitted, CT damage observed in 1. APGENCO to furnish to PCSC forum (i) A3-size Single APGENCO/ Yet to be informed
Chitoor-Main bay (404). Main breakers
Line Diagram of SDSTPS, and (ii) the sequence of
PGCIL (SR-I)
connected to bus-1 (401, 404, 407, 410) got
events with time stamp showing the protection that opened
tripped on operation of bus bar protection. Unit- Tie-CB (405) at SDSTPS.
1 tripped on operation of MFT. Unit-2 was not
in service
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.
Page 17 of 18
Pending
Pending
Annexure-IV
47/II/7 Tripping of
31-07-2015
220kV Kadra- at
Karwar line11:44 hrs
1&2 and
220kV
Kaiga-Kadra
line
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.
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.
KPTCL/
KPCL/
NPCIL
Yet to be informed
Pending
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.
47/II/9 Tripping of
03-08-2015
400kV Coastal- at
NTPL line and 15:43 hrs
running units
at NTPL
R-phase to earth fault had occurred in 400 kV
Coastal NTPL line. Line autoreclosed at NTPL
end and failed to reclose at Coatal end. Auto
reclose block was persisting due to PLCC
channel fail. Also running Units-1&2 at NTPL
tripped on operation of GT differential
protection.
NTPL/ CEPL Yet to be informed
Pending
48/III/ Tripping of
11
400 kV
Kurnool –
Srisailam line
Tripped at both ends on Y-Phase to ground
1. TSGENCO/ APTRANSCO to carry-out PLCC end-to-end TSGENCO/ Yet to be informed
zone-1fault. Attempt for auto-reclose could not testing in co-ordination with APTRANSCO/ TSGENCO to APTRANSC
be established.
sort out reception of signals on 400 kV Kurnool – Srisailam O
line.
Pending
400kV Kurnool-Srisailam line - distance
protection zone-2 had operated at Srisailam
end. However from DR, R-phase to earth fault
and zone-2 start were observed. Breakers at
Kurnool end tripped on direct trip receive from
Srisailam end.
TSGENCO/ Yet to be informed
APTRANSC
O
Pending
PGCIL (SR-I) Yet to be informed
/ KPTCL
Pending
NLC / PGCIL Yet to be informed
(SR-II)
Pending
03-10-2015
at 04:40 hrs
on
49/II/1 Tripping of
26-10-2015
1
400/220 kV
at 14:31 hrs
ICT-2 at
Kurnool
Substation and
400kV
KurnoolSrisailam line
50/II/8 Tripping of
12-11-2015
400kV Gooty- at 00:20 hrs
Nelamangala
line
ICT-2 Main-CB tripped due to operation of
bus bar protection, and Tie-CB tripped due to
DT receipt from Srisailam
1. NTPL to ensure (i) proper DATE settings, and (ii) timesync with GPS for DR and EL at NTPL.
2. CEPL to furnish remedial measures taken regarding
PLCC channel failure.
1.TSGENCO in coordination with APTRANSCO to carry
out end-to-end testing of PLCC channels by 15.12.2015 on
400 kV Srisailam – Kurnool S/C line and 400 kV Srisailam
– Sattenapalli D/C line.
2. TSGENCO and APTRANSCO to make A/R functional
on 400 kV Srisailam – Kurnool line.
3. TSGENCO to resolve configuration problems with the
newly commissioned relays at Srisailam LB so that
unwarranted DT sending to remote ends is addressed.
R-phase to earth fault had occurred in Line.
1. For Gooty –Nelamangala line, PGCIL (SR-I) and
Line did not auto-reclose from both ends. It
KPTCL to provide 3-ph trip logic at their respective ends
was mentioned that Y&B pole breakers at
upon detection of PLCC link failure during dead-time of
Neelamangala tripped on operation of pole
A/R operation.
discrepancy and backup impedence protection
2. PGCIL (SR-I) to make GPS functional at Gooty SS, and
for line reactor got operated.
ensure time-sync of various DR’s and EL’s with it (GPS).
3. PGCIL (SR-I) /KPTCL to furnish reason for the operation
of Backup impedance protection of the line reactor at
Nelamangala end and the remedial measures taken to PCSC
forum.
50/II/1 Tripping of
14-11-2015
1
400kV Neyveli at 4:01 hrs
TS2-Pugalur
line
Line tripped on operation of over voltage
NLC to configure DT receipt event from Pugalur for
protection at Pugalur end. However from DR it triggering DR and EL at NLC TPS II.
was observed that the voltages were below the PGCIL (SR-II) to check drop-off to pick-up ratio of OVR
O/v stg-1 threshold limits
relay at Pugalur and configure its operation as per SRPC
provided OVR gradings.
Page 18 of 18
Annexure-V
Pending Remedial Measures/ Actions taken
for the Critical Tripping Incidents (as on 11-02-2016)
Outage
date/time
03-11400/220 kV ICT-2 AT KAIGA 2015/08:26:
00
Sl.No. Element Name
1
Revival
date/time
03-112015/09:49:
00
Reason for Outage
TRIPPED ON
DIFFERENTIAL
PROTECTION
Sender/ Receiver
KAPS
Remedial Measures/ Actions
taken
To-be-discussed
2
400 Kv NCTPS - SVCTM-I
04-1204-12TRIPPED ON B-PH TANGEDCO /
2015/03:54: 2015/04:58:
FAULT
TANTRANSCO
00
00
TANTRANSCO/TANGEDCO
: Temporary fault. AR lockout
at both ends. No visible fault
and feeder normalised on
04.12.2015 at 04:58 hrs.
3
400 kV TRIVENDRUM TIRUNELVELI 1
11-122015/04:56:
00
PGCIL (SR-II): A/R scheme
will be tested at Trivandrum
End in Feb end.
4
400/220 kV ICT-2 AT
CHITTOOR
11-1211-12BUCHOLZ RELAY
APTRANSCO
2015/07:12: 2015/16:23:
OPERATION
00
00
To-be-discussed
13-1214-12Y-PH LA BLAST @
2015/22:42: 2015/17:33:
TANTRANSCO
THVLM END
00
00
TANTRANSCO: 3-Phase Trip
at Alamathy due to B-phase
LA failure. At Thiruvalam end,
Direct Trip received from
Alamathy.
5
400 KV ALAMATHI THIRUVALLAM-1
B-N FAULT
Page 1 of 8
PGCIL (SR-II)
Annexure-V
6
400 kV ALAMATHI VALLUR 2
7
400 kV MYSORE KOZHIKODE 1
8
400 kV KALPAKKA VEMAGIRI 2
9
220 kV AMBEWADI PONDA 1
10
11
TANTRANSCO: 3-Phase Trip
at Alamathy end due to Direct
13-1218-12Trip received from Vallur for
Y-PH LA BLAST @
2015/22:42: 2015/08:58:
TANTRANSCO / NTECL
the failure of B phase LA at
THVLM END
00
00
400kV Alamathy - Thiruvalam
feeder at Alamathy SS.
25-1225-122015/13:40: 2015/13:59: Y-N FAULT
00
00
31-12CONCDUCTOR
2015/09:06:
SNAPPING
00
PGCIL (SR-II)
PGCIL (SR-II): Tripped during
OPGW stringing works.
APTRANSCO
To-be-discussed
01-0101-012016/13:30: 2016/13:50: DFR ACTED
00
00
KPTCL
KPTCL: Suspected high
resistive transient fault, the line
tripped on DEFR. Stood OK
after test charging.
765 KV RAICHUR SHOLAPUR 2
02-012016/10:46:
00
PGCIL (SR-I) / PGCIL
(WR-I)
To-be-discussed
400 Kv SATTENAPALLI SRISAILAM 1
03-012016/23:58:
00
CONDUCTER
SNAPPING
DISTANCE
PROTECTION
APTRANSCO /
TSGENCO
TSGENCO: Auto reclose was
disabled at Srisailam end for
all (5) 400kV feeders.
APTRANSCO:
12
400 Kv PALLAKAD TRICHUR 1
04-0104-01PLCC
2016/18:28: 2016/18:38: MALOPERATION PGCIL (SR-II)
00
00
AT TRICHUR END
Page 2 of 8
To-be-discussed
Annexure-V
13
14
15
400 kV RAMAGUNDAM N'SAGAR 2
HVDC GAJUWAKA POLE 1
07-0107-01REPLAY
2016/21:07: 2016/21:32: MALOPERATION
00
00
@ RGDM END
12-0112-012016/21:28: 2016/22:33: DUE TO LOW DC
00
00
12-0112-01TRIPPED DUE TO
400/220 kV ICT-2 AT GOOTY 2016/16:27: 2016/17:10: DIFF RELAY
00
00
MALOPERATION
Page 3 of 8
NTPC / PGCIL (SR-I)
PGCIL (SR-I): The line was
holding from N'Sagar end. As
informed by NTPC, the line
tripped at RDM end only due
to mal-operation of L/O relay.
NTPC: Direct trip was
received and lockout relay has
acated. PLCC levels were
checked and found ok.
PGCIL (SR-I)
PGCIL (SR-I): Tripped due to
Low east bus voltage during
tripping of 400kV JeyporeGajuwaka -2 Line. System
fault beyong control of
POWERGRID
PGCIL (SR-I)
PGCIL (SR-I): Tripped on maloperation of differential
protection P543. The same is
being taken up with OEM, M/s
Alstom.
Annexure-V
16
17
400 kV JEYPORE GAZUWAKA 2
400 kV JEYPORE GAZUWAKA 1
12-0112-01TRIPPED DUE TO Y-PGCIL (ER-I) / PGCIL
2016/21:28: 2016/22:21:
N FAULT
(SR-I)
00
00
PGCIL (SR-I): Tripped on Y-N
fault. A/R attempted but unsuccesful due to persistant
fault. The thourough patrolling
of line carried out and no
abnormality found. Heavy fog
and mist observed on the day
of tripping may be the reason
for fault.
12-0112-012016/03:10: 2016/04:17: R-N FAULT
00
00
PGCIL(SR-I): Tripped on R-N
fault. A/R attempted but unsuccesful due to persistant
fault. The thourough patrolling
of line carried out and no
abnormality found. Heavy fog
and mist observed on the day
of tripping may be the reason
for fault.
Page 4 of 8
PGCIL (ER-I) / PGCIL
(SR-I)
Annexure-V
18
400 kV JEYPORE GAZUWAKA 1
19
400 kV GUTTUR NARENDRA 1
20
21
22
23
24
25
12-012016/04:24:
00
17-012016/18:53:
00
17-01400 kV GUTTUR 2016/18:53:
NARENDRA 2
00
17-01400 kV GUTTUR - HIRIYUR 2 2016/18:53:
00
17-01400/220 kV ICT-1 AT
2016/18:53:
GUTTUR
00
17-01400/220 kV ICT-2 AT
2016/18:53:
GUTTUR
00
17-01400 kV KAIGA - GUTTUR 2 2016/18:53:
00
17-01400 kV GUTTUR - HIRIYUR 1 2016/18:53:
00
17-012016/20:25:
00
17-012016/20:28:
00
17-012016/20:08:
00
17-012016/19:55:
00
17-012016/19:58:
00
R-N FAULT
PGCIL (ER-I) / PGCIL
(SR-I)
PGCIL(SR-I): Tripped on R-N
fault. A/R attempted but unsuccesful due to persistant
fault. The thourough patrolling
of line carried out and no
abnormality found. Heavy fog
and mist observed on the day
of tripping may be the reason
for fault.
BUS FAULT AT
GUTOOR
KPTCL / PGCIL (SR-II)
To-be-discussed
BUS FAULT AT
GUTOOR
KPTCL / PGCIL (SR-II)
To-be-discussed
BUS FAULT AT
GUTOOR
KPTCL / PGCIL (SR-II)
To-be-discussed
BUS FAULT AT
GUTOOR
KPTCL
To-be-discussed
BUS FAULT AT
GUTOOR
KPTCL
To-be-discussed
BUS GAULT AT
GUTOOR
KAPS / KPTCL
To-be-discussed
B-N FAULT
KPTCL / PGCIL (SR-II)
To-be-discussed
Page 5 of 8
Annexure-V
26
27
28
29
30
31
32
33
34
35
36
18-012016/12:46:
00
19-01400/230 kV ICT-2 AT
2016/11:57:
MADURAI
00
19-01400/230 kV ICT-1 AT
2016/11:57:
MADURAI
00
20-01400 kV NELAMANGALA 2016/15:14:
HOODY 2
00
20-01400 Kv RAICHUR - YTPS
2016/12:20:
00
20-01400/220 kV ICT-2 AT HOODY 2016/06:14:
00
24-01400/220 kV ICT-1 AT
2016/09:15:
CHITTOOR
00
25-01400 Kv SHANKARPALLY2016/13:56:
MAMIDIPALLY
00
26-01400 Kv IL&FS 2016/13:03:
NAGAPATTANAM-1
00
28-01400 kV MYSORE 2016/12:53:
KOZHIKODE 1
00
28-01220 kV AMBEWADI 2016/14:01:
PONDA 2
00
400/220 kV ICT-1 AT
MUNIRABAD
18-012016/13:26:
00
19-012016/12:46:
00
19-012016/12:48:
00
20-012016/15:36:
00
20-012016/14:51:
00
20-012016/09:30:
00
25-012016/16:00:
00
26-012016/13:23:
00
28-012016/13:18:
00
28-012016/19:20:
00
TRIPPED WHILE
TESTING
PGCIL (SR-I)
BREAKER
BUS BAR
OPERATED AT 220 PGCIL (SR-II)
KV S/S
BUS BAR
OPERATED AT 220 PGCIL (SR-II)
KV S/S
To-be-discussed
To-be-discussed
To-be-discussed
TRIPPED DUE TO
PDR
KPTCL
To-be-discussed
MAL OPERATION
OF RELAY
KPCL
To-be-discussed
TRIPPED
KPTCL
To-be-discussed
DIFFERENTIAL
PROTECTION
APTRANSCO
To-be-discussed
DT RECEIVED
TRIPPED AT
SKPLY END
TSTRANSCO
To-be-discussed
R-N FAULT
IL&FS / PGCIL (SR-II)
To-be-discussed
B - N FAULT
PGCIL (SR-II)
To-be-discussed
DISTANCE
PROTECTION
KPTCL / GOA
To-be-discussed
Page 6 of 8
Annexure-V
37
38
39
40
41
42
43
44
45
46
28-01400 Kv KRISHNAPATNAM 2016/17:07:
CHITTOOR -1
00
29-01400 kV HNPCL- KALPAKKA
2016/11:02:
1
00
31-01220 kV AMBEWADI 2016/14:05:
PONDA 2
00
31-01220 kV AMBEWADI 2016/14:00:
PONDA 1
00
31-01400 Kv VTPS - MALKARAM
2016/14:23:
2
00
01-02400 kV CHITTOOR - SPDR
2016/09:55:
00
01-02400 kV GUTTUR 2016/12:06:
NARENDRA 2
00
01-02400 kV VIJAYAWADA 2016/12:57:
NELLORE 1
00
01-02400 kV VIJAYAWADA 2016/06:30:
NELLORE 2
00
02-02400 kV KHAMMAM 2016/07:18:
KALPAKKA 2
00
28-01RELAY
2016/17:20:
MALOPERATION
00
BUS -1 TRIPPED
DURING E S/D BY
AP
01-022016/10:40:
00
01-022016/12:33:
00
01-022016/18:49:
00
01-022016/06:32:
00
02-022016/15:12:
00
APGENCO /
APTRANSCO
To-be-discussed
APGENCO /
APTRANSCO
To-be-discussed
DEF OPERATED
KPTCL / GOA
To-be-discussed
B-N FAULT
KPTCL / GOA
To-be-discussed
R-N FAULT
APGENCO /
TSTRANSCO
To-be-discussed
L/R PROTECTION
OPERATED
APTRANSCO / PGCIL
(SR-II)
To-be-discussed
KPTCL / PGCIL (SR-II)
To-be-discussed
PGCIL (SR-I)
To-be-discussed
TRANSIENT
FAULT
PGCIL (SR-I)
To-be-discussed
INSULATOR
FLASH OVER
PGCIL (SR-I) /
APTRANSCO
To-be-discussed
TRIPPED AT GTR
END MAL
OPERTION
TRIPPED ON Y_N
FAULT 257 KM
FROM VJA
Page 7 of 8
Annexure-V
47
220 kV IDUKKI UDUMALPET
03-0203-02TRIPPED ON B-PH
2016/11:54: 2016/12:19:
KSEB / TANTRANSCO
FAULT
00
00
TANTRANSCO: AR
successful at Udumalpet end.
Feeder tied at Idukki end on
03.02.2016 at 12:19 hrs.
KSEB:
48
400 kV MYSORE KOZHIKODE 2
04-0204-02TRIPPED WHILE
2016/12:24: 2016/13:07: CARRYING OPGW PGCIL (SR-II)
00
00
WORKS
To-be-discussed
49
400/220 kV ICT-3 AT
RAICHUR
05-0205-02TRIPPED DUE TO
2016/03:01: 2016/05:24: TRIPPING OF RCR- KPCL
00
00
SEDAM LINE
To-be-discussed
50
400 Kv NTPL - TTRNPS
51
400 kV VEMAGIRI - GVK
(JPD) 1
52
400 kV VEMAGIRI - GMR 2
05-022016/11:47:
00
07-022016/21:20:
00
09-022016/12:57:
00
05-02HOT SPOT @ NTPL
2016/13:05:
NTPL / PGCIL (SR-II)
END
00
TRIPPED ON
RELAY MAL
APTRANSCO / GVK
OPERATION
09-02RELAY
2016/14:04:
APTRANSCO / GMR
MALOPERATION
00
Page 8 of 8
To-be-discussed
To-be-discussed
To-be-discussed
Annexure- VI
COASTAL ENERGEN PVT. LTD
7th Floor Buhari Towers. 4, Moores Road. Chonnai - 600 006. INDIA.
Tel: +91 4442964296. Fax: +91 4442964297. www.coalandoil.com/www.coastalenergen.com
07 Jan 2016
Energen/POSOCOI07-2016
To.
~Executive Director
Southern Region Load Dispatch Center
29 , Race Course Cross Road
Bangalore - 560 009
Dear Sir.
Sub: Const r aint s in transmitting full output from 2x600 MW Coastal Enerqen's Mutiara
The rmal Power Plant - Approval -r eg
Ref . . Mirutes of the Meeting "2x 600 MW Mutiara Ther'T1oi Power' Project-Permission for
Synchronizatio~ and declaration of COD of unit _2" held in CEA on 11.12.2015
We thank SRLDC for permitting Energen to Synchronize the Unit # 2 on 26th Dec 2015
and to go for full load on 2nd Jan 2016 .
As per MOM under reference, it is ind icat ed that the totol power evacuation from t his
complex should not exceed 1350 MW. In view of this. with both the units of NTPL runn ing
full and exporting 950 MW, Energen can export only 450MW as against 1100 MW.
Coastol Energen has a lready given a commitment to CEA that work of dedi cated
TI'onsmissior. system will be completed within six months . · O~ders hove been placed on f1/..'s
Unitech Power transmission Ltd for Construction of Transmiss ion Lines with 0 compler .on
period of six months. As inf or med earlier, orders have been placed on MIs ABB f o'
Construction of two nos of 400 KV bays at Tuticorin POWERGRID Pooling Station with a
completion period of si x months and they have started the work.
Running
of. both Units at full capacity is necessary to supply power and also to -service the
.
loans and interesfto 18 banks which have funded the project.
As inoicct ed in the. attached dmqrom, to r est r ict the Power flow in NTPL Bus to the e xtent
of 13!50 MW and to maintain Grid s ta bilit y Coastal Er>erqen propose to implement the
followinq with the concurrence of SRLDC '/SRPC:-
Page 1 of 3
Annexure- VI
Page 2 of 3
Annexure- VI
Page 3 of 3