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SOUTHERN REGIONAL POWER COMMITTEE BENGALURU
Minutes of the 41st
Meeting of Protection Coordination Sub- Committee
(PCSC – 41) of SRPC held on 26.02.2015
1. Introduction
The 41st meeting of Protection Coordination Sub-Committee (PCSC) was held on 26
th
February, 2015 in the Conference Hall of Southern Regional Power Committee, Bangalore.
The list of participants is enclosed at Annexure-I.
Shri S.R.Bhat, Member Secretary (MS), SRPC welcomed the Members and Participants to the
meeting and briefed them on the following points:
A Special Meeting was held on 19th
February 2015 at IL&FS to analyze cause for the Grid
Incidents that occurred on the NLC 1 Exp – IL&FS – Trichy 400 kV S/C line during
January-February, 2015. M/s IL&FS and M/s NLC had been recommended to carry out
certain system-tests and modifications relating to Auto –Reclose operation, PLCC
operation, Over- Voltage relay settings, DEF settings, etc. to prevent recurrence of such
trippings. PCSC forum appreciated the cooperation extended by PGCIL, NLC and IL&FS
in resolution of the protection issues in that corridor. The Minutes of the Meeting are
enclosed at Annexure-II.
With reference to Petition No. 374 filed by TANTRANSCO before Hon’ble CERC seeking
time extension for Phase-I and Phase-II activities of Protection Audit Recommendations, all
Southern Region Constituents had been directed to file status of implementation of protection
system in their respective States to the Commission by 31st March 2015.
Remedial measures/ action taken in respect of tripping incidents, some as old as August-
2014 were still awaited. He requested the Constituents to furnish the measures/ action
taken to SRPC at the earliest.
On account of paucity of time in monthly meetings of OCC, state-wise meetings had been
conducted to address the specific issues. In this regard, a Meeting was held with M/s
KPTCL to address various issues including installation of U/V relays. Similarly, a Meeting
had been held with representatives of Andhra Pradesh and Telangana to sort out various
issues including segregation of feeders between Andhra Pradesh and Telangana for the SPS
schemes.
A presentation on Protection Management System software would be delivered by M/s
PRDC later in the meeting. He requested the Constituents to use the opportunity to seek
any clarifications on this matter
22. Confirmation of the Minutes of the 40th
PCSC meeting held on 29-01-2015
SE (Protection), SRPC stated that Minutes of the 40th meeting of PCSC were circulated vide
SRPC letter No. SRPC/SE-III/ PCSC-40/2015/1000-1031 dated 16.02.2015. In this regard,
following observations were received from TANTRANSCO and NTPC, Ramagundam.
(i) TANTRANSCO Observations: SE (Design, P&C), TANTRANSCO stated that in
Annexure-II to the Minutes, the tripping incident relating to 220 kV Sedam –Tandur line at
Sl. No. IV(1), the corresponding Constituent was not TANTRANSCO, and as such the
recommendation may be suitably modified. Accordingly, the recommendation given
therein was modified as follows:
“KPTCL was requested to explore the possibility of providing
A/R feature to this line and submit the remedial measures to the PCSC forum.”
(ii) NTPC, Ramagundam Observations: AGM (EM), NTPC, Ramagundam stated that in the
40th
meeting of PCSC, the recommendation of Power System Analysis Group – 11
(PSAG-11) relating to implementation of Auto-Reclosure (A/R) on Ramagundam –
Chandrapur 400 kV D/C line was discussed, but not reflected in the Minutes at Sl. No. 13
(i). Accordingly, the deliberations of the PCSC forum as given under on the issue referred
may be treated as being included at Sl. No. 13(i) of the Minutes:
“With respect to the recommendation of PSAG-11 regarding implementation of
Auto-Reclosure (A/R) on Ramagundam – Chandrapur 400 kV D/C line, KSEB
Representative suggested that 3-Phase A/R may be got implemented at both ends.
He explained that 1-Phase A/R is basically provided to clear a transient L-G fault
on a faulty phase without jeopardizing the reliability of the grid by making
available the other two phases for service. However, in the instant case with 3-
Phase A/R at Bhadrawati, no useful purpose will be served with 1-phase A/R at
Ramagundam, as all the 3-Phases will be in or out together. Moreover, due to the
capacitive coupling that exists between the out-of-service phase and the other two
in-service phases, the time required to bring the out-of-service Phase into service
will be significantly higher compared to that obtained with 3-Phase A/R in place at
both ends.”
The PCSC forum noted KSEB’s observations and recommended 3-Phase A/R at
NTPC, Ramagundam end.”
With this, the Minutes of the 40th
meeting of the PCSC were confirmed.
3. Details of Grid Disturbances (GD’s), Grid Incidents (GI’s), Line Trippings due to PLCC
mal- operation, Auto-Reclose non-operation
The trippings due to GD’s, GI’s, PLCC mal-operation and Auto–Reclosure failure/non-
operation that had occurred during the period, January – February, 2015 were discussed in the
Meeting. The deliberations and recommendations of the PCSC-forum are enclosed at
Annexure–III.
4. Remedial measures/ Action taken for tripping incidents of the transmission elements
under forced outage
The tripping incidents of the transmission elements under forced outage for which the
remedial measures/ action yet to be taken were discussed in the Meeting. Constituents were
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 12.03.2015 is
enclosed at Annexure-IV.
5. Status of pending PCSC recommendations
The status of implementation of pending PCSC recommendations were discussed in the
meeting. The constituents were requested to kindly submit the status of their compliance latest
by 20.03.15. The updated status of the same as on 13.03.2015 is enclosed at Annexure-V.
6. Status of Protection System Analysis Group (PSAG) Recommendations
The status of implementation of recommendations of the following PSAG meetings was
discussed in the Meeting.
PSAG -10 Grid Disturbances at Kadra, Kodasalli,
Kaiga during Sept – Oct, 2014
KPCL, NPCIL
PSAG -12 Grid Disturbances at Upper Sileru HPS
during Nov – Dec, 2014
APGENCO
The compliance reports as furnished by the KPCL, APGENCO are enclosed at Annexure-VI,
Annexure-VII respectively.
Status of the recommendations of PSAG-11 regarding operational aspects of HVDC,
Bhadrawati could not be discussed as the same was not furnished. PGCIL (SR-I & II) were
requested to kindly coordinate with their WR-counterparts in this regard, and furnish the
compliance of PSAG-11 recommendations to SRPC at the earliest.
7. 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 are requested to submit the certificate on
healthiness of batteries on monthly basis (i.e. on 7th
day of the month) to SRPC.
The sought status for the month of January, 2015 has not been received from the following
SR-Constituents:
TSGENCO (Hydro), TANGEDCO, PGCIL (SR-I), NPCIL (MAPS), NTECL, JSWEL
& GMR
8. Suggestions for providing settings for High set of Earth fault relay on HV side of
Generator Transformer (with Star connection on HV side and Delta connection on LV
side)
KSEB Representative presented his views on providing settings for High set of Earth fault
relay on HV side of Generator Transformer (GT) [with Star connection on HV side and
Delta connection on LV side]. During deliberations, the following salient points were noted:
1. Delta –Star transformer configuration makes transformer impedance as its zero
sequence impedance. There will not be any effect on High-Set setting from whatever
that may be connected to delta side (whether it is open, generator connected, load
connected)
2. For star –star power transformers, zero sequence impedance will be affected by the
connected load impedance on the other side of the transformer in series with
transformer impedance.
3. In the case of power transformers with delta connected tertiary winding, the effect will
be sum of those provided above (vide items 1 and 2). The zero sequence impedance will
be shunted by the impedance of tertiary winding.
4. It was noted that high-set unit of E/F relay of generator transformer trips for feeder
ground faults. This is due to the flow of zero sequence currents through transformer
neutral. Time of high-set unit of E/F relay (IDMT) is to be properly coordinated with
distance protection and directional earth fault relay on the feeders.
5. The setting of high set of earth fault relay shall be such that it will not mal-operate for
close-in external fault even at highest fault level condition. However, this relay shall
operate for in-zone fault, i.e., for faults inside phase side CTs and transformer neutral.
This will be possible only when recommended high set setting is provided in the earth
fault protection in residual connection of Transformer phase side CTs. Therefore, high
set for earth fault protection shall only be provided on residual connected earth fault
protection from phase side CTs. The high set unit shall not be provided in the earth fault
protection connected to neutral CT.
6. As shown in the write-up (ref: Agenda, PCSC-41), the total fault current contributions
through Generator Transformer neutral will be highest when all elements, viz., GT and
Generator and the System to which they are connected are all in service. Further, to
account for the difficulties in getting the exact sequence network picture (system
configuration), DC Offsets in CTs, X/R in systems, etc., the setting for High-set can be
arrived at by multiplying the above maximum fault current with a suitable factor, say
1.3. However, as the protection area of high-set unit of earth fault relay is between CTs
on HV side of GT and (including) transformer HV winding, which is normally covered
by Restricted Earth Fault protection and Transformer differential protection (these are
more sensitive than high set unit earth fault relay), the High-Set may be provided with 5
cycles delay (100 msec).
9. Dynamic study data submission
All SLDCs were requested to direct the embedded IPPs connected at 220 kV and above
voltage level to submit completed dynamic study format to SRPC, Secretariat. Constituents
were requested to submit the Dynamic study data at the earliest.
10. Network configuration changes
As per the information furnished by the SR-Constituents to the OCC forum in the 104th
Meeting held on 10.02.2015 (Minutes circulated on 02.03.2015), it is observed that no
network configuration changes (additions/ deletions/ modifications of transmission
elements) took place during the month of January, 2015.
11. New formats for reporting failure of substation equipment / towers of transmission
lines at 220kV and above
It is intimated that CEA has revised formats for reporting of failures of substation
equipment and failure of transmission line towers at 220 kV & above. The new formats are
enclosed at Annexure-VIII. These formats for reporting the failures are also available in
CEA's website (www.cea.nic.in).
12. SPS for Neelamangala – Peenya lines
In the 40th meeting of PCSC, the SPS for Peenya-Nelamangala was discussed; wherein
KPTCL informed that the existing SPS had been designed to handle load relief of around
50 MW for three lines of Nelamagala- Peenya corridor. However presently there are 4
lines, each loaded to around 150-200 MW. In view of the changed scenario, KPTCL
proposed that they would review the existing SPS so as to provide a load relief of up to
200 MW for each line whenever any line carries more than 200 MW. The finalized SPS
scheme as furnished by KPTCL is enclosed at Annexure-IX. Members may kindly note.
13. Compliance of Hon’ble CERC Orders
13.1 Petition No. 146/MP/2013 with I.A. 36/2013: Order dated 20.02.2014
Compliance of Regulations 5.2 (r) 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.
The following constituents are to submit the updated status of filing of
petition/affidavit to SRPC Secretariat at the earliest: APTRANSCO.
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).
13.2 Petition No. 167/Suo- Motu/2012: Order dated 22.02.2014
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 with 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.
13.3 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.
14. Date & Venue of the next Meeting
It is informed that the 42nd
PCSC meeting will be held on 26.03.2015 (Thursday) at 10.30
hrs at SRPC Secretariat, Bangalore.
X ------------------------------------------ X ------------------------------------------ X
Annexure-I
Annexure-I
Annexure-I
Annexure-I
Annexure-I
Annexure-II
Record Notes of Discussions of Special Meeting held at IL&FS on 19-02-2015
to discuss the Grid Incidents that occurred in the months of January-
February, 2015
SRPC Special committee had visited IL&FS power station on 19-02-2015 for investigating the
tripping of lines pertaining to IL&FS. The list of participants are enclosed at Annexure-I.
Four tripping pertaining to lines connected to IL&FS had occurred during January and February
2015. It was observed that lines had tripped once due to several reasons cited below:
R-phase to earth fault
Over voltage tripping
PLCC mal-operation
Manual error.
Following were the major observations and recommendations of the committee:
1. After LILO works, Main-2 distance relay settings were not revised at NLC Expansion
line for 400kV NLC Expansion -IL&FS line. The settings were asked to be revised.
2. Auto-reclose scheme is to be tested at both for 400kV NLC Expansion -IL&FS as line
did not auto reclose during an R-phase to earth fault in line. NLC Expansion needs to
review distance protection scheme in view of three phase tripping with receipt of carrier
signal by 1st Week of April 2015.
3. End to End PLCC testing was required to be carried out for 400kV NLC Expansion -
IL&FS line. PLCC Ch-1 is unhealthy for this line. It was proposed to replace both the old
PLCC panels. POWERGRID and NLC Expansion had agreed to replace the old PLCC
panels. In this Regard NLC Expansion was requested to approach GM (O& M) SR-II for
up gradation of PLCC.
4. Drop off to Pick up ratio of over voltage relay was asked to be tested at IL&FS.
5. Minor changes in time delay of DEF setting was proposed i.e, an additional time delay of
1.1 sec was to be added so that DEF operates after Zone-3 time. Settings to be revised at
IL&FS end.
6. Remaining protection settings were found to be in-order at IL&FS. The D.R & E.L were
functional and time synchronized with GPS
7. IL&FS representative was asked to upload the FIR, D.R and E.L on SRLDC trip web
portal within 24hrs of occurrence of the incident.
8. IL&FS representative had informed that necessary precautions have been taken to avoid
tripping of lines due to human error.
9. IL&FS was asked to carry out patrolling in LILO Portion.
Annexure-II
Annexure-II
1
Grid Occurrences
I. GRID DISTURBANCES (GD):
1 Complete outage at 220kV Kadra power Station of KPCL (GD-1)
(i) Date and Time of Event 16-02-2015 at 12:56 hrs
(ii) Location 220 kV Kadra Hydro Power Station
(iii) Plant and/or Equipment
directly involved
All connected elements (Generating plants and
220kV feeders) at Kadra Station.
(iv) Reported Disturbance /
Fault
Triggering incident was B-phase to earth fault
in 220kV Kadra-Kodasalli line. This line
tripped from Kodasalli end only in Zone-1.
220kV Kaiga-Kadra tripped in Zone-3 from
Kaiga end. Tripping of evacuating lines caused
bus shut down at Kadra hydro station.
(v) Generation/Load Loss Nil
(vii) Category GD-1
SLD:
Deliberations:
KPCL:
1. A fault (B phase to earth) occurred on 220kV Kadra-Kodasalli line. As a result,
At Kodasalli end, Kadra line tripped on DPR, Zone-1, and B-N fault.
At Kadra end, Distance protection provided on Main-1 relay (PZ-1000)
picked up in Zone-1, but DC fuse was blown out prior to tripping and the
relay could not operate. The back-up relay of English Electric make, though
wired, is yet to be commissioned.
At Kaiga end, Kadra line tripped on DPR, Zone-3, and B-N fault.
At the time of tripping, there was no generation at Kadra
Kadra Kodasalli
Kaiga
G1
G2
G3
G1
G2
G3
Karwar Nagjheri PH
S/D hand trip Z1 (B)
trip
Z3 (B) trip
Annexure-III
2
As Karwar station is a radial feeder, the power flow is zero.
2. At Kadra HPS, there are two battery banks (1 & 2) , but the supply to protection
system is availed from one bank only. The second bank, though available, is not kept
in service. The switching between two battery banks is being carried out manually.
3. Corrective Action:
The Fuse was replaced at Kadra station.
SRLDC:
At Kaiga end, Zone-3 operation of Kadra – Kaiga line is in order.
Fault current observed for 652 ms in B-phase of 220kV Kaiga-Kadra line at Kaiga
end.
Trip Coils 1 & 2 (TC-1, TC-2) of the circuit breakers shall get supply from different
sources (i.e. bank-1, and bank-2).
From 27.02.2015 onwards, Kadra-Kodasalli line shall be kept open and Kadra
generation shall be stalled and continue to remain so till the issues are addressed and
completed.
KSEB:
As the fuse was blown out, there could be some short circuit that had to be located
and cleared.
KPTCL:
On many CBs, there is an arrangement of an NC coil dropping out in case of failure
of one battery bank and starting the other battery bank.
Nowadays an arrangement is being made to have independent DC sources from
DCDB itself.
By the first week of March, 2015, RT team from KPTCL would be ready to test the
relays at KPTCL stations.
DC supply cables, breaker control cables, and trip coils have to be checked.
SRPC:
KPCL is requested to expedite the implementation of the recommendations of earlier
PCSC meetings, protection audit, and PSAG meetings.
A meeting is proposed to be convened in the first week of March, 2015 with KPCL
higher management to discuss the status of their pending protection issues.
Recommendations:
KPCL to make functional the Main2 (EPAC) relay with the help of KPTCL at the
earliest.
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.
KPCL to ensure supply for Main-1& Main-2 protections, Trip Coils (TC1, TC2)
from separate battery banks.
Annexure-III
3
2 Complete outage at 220kV Bahoor Substation of Pondicherry (GD-1)
(i) Date and Time of Event 15-02-2015 at 11:20 hrs
(ii) Location 230 kV Bahoor Substation
(iii) Plant and/or Equipment
directly involved
All connected elements at Bahoor Substation.
(iv) Reported Disturbance /
Fault
Bus fault occurred in 110kV bus at 230/110kV
Bahoor substation due to failure of Y-phase main
bus strain insulator. 220kV lines connected to
Bahoor (viz., Bahoor- NLC TPS II and Bahoor –
Pondy) tripped from remote end on operation of
back up protection.
(v) Load Loss 75 MW
(vii) Category GD-1
Deliberations:
From Trip Reports, the following were noted:
There was a fault at 110 kV bus at Bahour station. ICT back up protections did not
operate.
E/F (Y-B) relay operated (0.861 sec) at NLC – 2 on NLC-2 – Bahour 230 kV line.
Distance relay operated in Zone-3 (Y-B) (1.435 sec) at PGCIL Pondicherry substation
on Pondicherry – Bahour 230 kV line.
Annexure-III
4
SLD:
Puducherry Electricity Department (PED):
There was a flash over on the strain insulator of the 110 kV bus bar conductors, due to
which the conductors got snapped and fell down on the ground causing bush fire.
The fault location was on 110 kV bus side which is inside the differential protection
zone of the 230/110 kV transformer. However, ICT back-up protection did not operate.
Bus bar protection was not provided for 110 kV bus at Bahour 230/110 kV sub-station.
Remote end feeders tripped on back-up protection (Pondy – Bahour tripped on
operation of Zone-3; NLC 2 – Bahoor tripped on operation of back-up E/F relay)
PT fuse alarm came on 220 kV side due to disturbance.
Relay testing is generally carried out by TANTRANSCO.
SRLDC:
It appeared that the substation was charged after the fault without carrying out any
fault analysis.
As the fault was inside the transformer differential zone, differential protection should
230 kV
Bahour Inox Eripakkam
Auto-1 Auto-2
NLC 2 Pondicherry (PGCIL)
Bahour (PED)
110 kV
Z3 (Y-B) - trip E/F (Y-B) - trip
hand trip
Y-phase jumper snapped;
fell on the ground;
resulted in bush fire
Annexure-III
5
have operated.
The fault was persisting for 1.5 seconds, but neither differential protection nor other
back up relays operated.
Relay settings for ICTs have to be tested and installed by 27.02.2015, otherwise
transformer would be kept opened till the testing is completed and relays are made
functional.
KSEB:
As there are two ICT’s on the same 110kV Bus, there might be a chance for sensing
only half of the total earth fault current (since it is a parallel connection) by each ICT.
The current sensed might have been below the Earth fault setting of the ICTs, so the
relay might not have got operated.
Need to check the current value and also the time settings of the Earth fault relay of
ICTs.
TANTRANSCO:
On invitation, relay testing would be done at Bahour station on chargeable basis.
Recommendations:
PED to investigate the cause of non-operation of ICT’s protection system (differential
protection, back-up protection) and review the relay settings suitably at Bahour S/S.
PGCIL to check the settings of distance relay and back-up relays for correctness of
operation at Pondy S/S.
3 Complete outage of Nagjheri Hydro power station of KPCL (GD-1)
(i) Date and Time of Event 22-02-2015 at 11:09 hrs
(ii) Location Nagjheri Hydro Power station
(iii) Plant and/or Equipment
directly involved
All connected elements at Nagjheri Hydro
Power station.
(iv) Reported Disturbance /
Fault
During de-synchronization of Unit-3, the Y-
pole of the CB did not open (was locked-out).
This caused LBB protection to operate
resulting in tripping of the Bus and all
connected 220kV lines and running units at
Nagjheri power station.
(v) Generation/ Load Loss 550MW
(vii) Category GD-1
Annexure-III
6
SLD:
Deliberations:
KPCL:
While desynchronizing unit#3, the circuit breaker got stuck up and did not open.
This caused LBB protection to operate resulting in tripping of the Bus and all
connected 220kV lines and running units at Nagjheri power station.
LBB and BBP are provided in separate relays at Nagjeri power house.
As the disturbance recorder is very old, obtaining report is difficult.
SRLDC:
LBB protection might have got trigger from low forward power relay
Report on tripping is not yet submitted even after one week of the incident.
Usually, during afternoon and night hours, the power house is under shutdown;
during these hours, the protection system should have been checked for ascertaining
the cause of station outage and got rectified.
KSEB:
Low forward power, negative sequence values, and operator emergency button
would initiate LBB relay.
Master trip relay for bus differential would also trip for LBB.
SRPC:
KPCL is requested to expedite the implementation of the recommendations of earlier
PCSC meetings, protection audit, PSAG meetings.
A meeting is proposed to be convened in the first week of March, 2015 with KPCL
higher management to discuss the status of their pending protection issues.
Recommendations:
KPCL to investigate the cause of Y-pole breaker lock-out of Unit-3, and take suitable
remedial measures within a week’s time
KPCL to furnish what caused LBB initiation and furnish LBB Scheme details to
PCSC forum
KPCL to furnish detailed tripping report (with DR & EL) of the incident
Nagjheri (KPCL)
L)
Bus bar protection
trip
GT
150 MW
Bidnal Hubli Ambewadi
Kodasalli
alli
G
G
G4 G3
G2
G1
Annexure-III
7
4 Complete outage at 220kV Sedam Substation of KPTCL (GD-1)
(i) Date and Time of Event 27-01-2015 at 8.00 hrs
(ii) Location 220 kV Sedam Substation
(iii) Plant and/or Equipment
directly involved
All connected elements at Sedam Substation.
(iv) Reported Disturbance /
Fault
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.
(v) Generation/ Load Loss Nil
(vii) Category GD-1
SLD:
Deliberations:
KPTCL:
R-Phase to ground fault occurred on 220kV Sedam-Shahapur line. As a result,
At Shahapur end, the line tripped on distance protection, Zone-1, RN, 1.26km.
At Sedam end, distance relay operated in Zone-2. But due to problem in the
breaker, it did not trip.
220 kV
Tandur
(TSTRANSCO)
Sedam (KPTCL)
Raichur Shahapur Humnabad
handtrip
Z1 (Rn) Z2
Z2 Line did not trip due
to problem in CB
Annexure-III
8
220kV Sedam-RTPS lines tripped at RTPS end on distance protection, Zone-2.
Due to tripping of source lines at RTPS and Shahapur end, 220 kV bus became
dead at Sedam Sub Station.
220kV Sedam-Tandur interstate line was hand-tripped.
Remedial Measures:
Problem in Shahapur line breaker was attended to at Sedam substation before
restoration of the line.
The resistive reaches of distance relays at Sedam substation have been revised.
Directions have been given to check the distance relay and back up relays of
Shahapur line at Sedam Substation.
220kV line distance relay settings at RTPS end have been reviewed.
Bus bar protection and LBB protection are not provided at Sedam; measures have
been taken to provide these protection schemes at Sedam and the same is in
tendering stage.
Similar kind of fault occurred on 15.02.2015 and it was noted that there was again a
problem with line CB. So, line CB was taken out of service and the bus coupler CB
is now used as line CB.
SRLDC:
It appeared that there is no A/R operation on Sedam – Tandur line, which is an
interstate line.
For interstate lines A/R shall be made available as envisaged in CEA’s Grid
Standards. SRLDC would be issuing notice to constituents shortly in this regard.
Further, A/R feature is to be provided for intrastate lines of the Constituents also and
SLDC shall monitor and ensure this.
Recommendations & Follow-up:
KPCL to provide Bus bar and LBB protections for 220 kV bus at Sedam S/s.
KPCL to implement A/R feature on 220 kV Sedam-Tandur inter-state line.
II. GRID INCIDENTS (GI):
Sr.
No.
Details of Events Date and Time Reason Category
1 Tripping of 400kV
Vijayawada-Nellore line 1
22-01-2015 at
11:39 hrs
line tripped on operation of TEED
protection at Vijayawada end and
direct trip was received at Nellore end
GI-2
Deliberations:
Vijayawada – Nellore-1 400 kV line tripped on operation of TEED- 1, B-ph protection at
Vijayawada end, even though there was no fault; DT was sent to Nellore end due to which
Nellore end CBs got opened.
Annexure-III
9
SRLDC:
TEED protection should operate only when the line isolator was in OPEN condition.
Non-operation of stub protection for non-fault unbalance condition to be ensured.
Noted with concern that the line was charged without analysing the fault.
Charging code for line won’t be given to constituents unless fault was analysed, relays involved
were tested and cause was removed.
PGCIL:
There was no fault in the line; it was a typical case of mal-operation of TEED protection.
As there was a man power shortage (and many stations were unmanned), analysis could not be
submitted immediately.
SRPC:
It appeared that there was a time difference of 3 seconds in EL’s of Vijayawada and Nellore.
It appeared that DTS from Vijayawada was not seen as DTS in Nellore EL.
Recommendations:
PGCIL shall review the TEED protection at Vijayawada end with their OEM group and
submit action taken report to PCSC forum.
2 Tripping of 400kV
Srisailam-
Mamidapalli-2
line and 400kV
Srisailam-
Satenapalli-1 line
23-01-2015 at
16:10 hrs
Bus-2 at Srisailam became dead while
converting Srisailam generator to
condenser mode. Direct trip was received
at Mamidapalli and Satenapalli end.
GI-2
Deliberations:
During the changeover of Srisailam Generator to Condenser mode, BBP for Bus-2 operated at
Srisailam LLB (Left Bank); Mamidapalli and Sattenapalli got tripped due to DT receipt from
Srisailam LLB.
SRLDC:
Reason for LBB operation shall be submitted by TSGENCO.
SRPC:
It was noted that no representative from TSGENCO attended the meeting.
As the event logger output was without millisecond time stamp, sequence of events could not
be ascertained within a second.
TSTRANSCO:
The DR at Mamidipally was being retrofitted, as such the details could not be furnished.
Reasons for BBP operation at Srisailam LLB would be obtained from TSGENCO, and
furnished to PCSC forum.
Recommendations:
TSGENCO to furnish the reasons for BBP operation at Srisailam LLB and the remedial
action taken to PCSC forum.
Annexure-III
10
3 Tripping of 400kV
NLC-1 EXP-
IL&FS line and
400kV IL&FS -
Trichy line
24-01-2015 on
13:15 hrs
400kV NLC-1 EXP- IL&FS line tripped
on a R-phase to earth fault. Line did not
auto-reclose. 400kV IL&FS - Trichy line
tripped at Trichy due to Direct trip receive
from IF&FS.
GI-2
Deliberations:
Tripping of 400kV NLC-1 EXP --- IL&FS line: R-phase to Ground fault occurred near IL&FS.
The line tripped at both ends in Zone-1 due to A/R operation. But at NLC-1 Exp, instead of 1-
Phase trip, three phase trip happened, due to which the line did not auto reclose successfully.
Tripping of 400kV IL&FS --- Trichy line: The voltage at IL&FS shot up resulting in operation
of OVR at IL&FS; Trichy end tripped due to DT receipt from IL&FS.
SRPC committee had visited IL&FS on 19-02-2015 to address the issues relating to frequent
trippings of the lines and the coordinating relay settings in view of LILO made at IL&FS.
NLC:
PLCC equipment has been tested at NLC end and it is working.
SRLDC:
400 kV NLC-1 Exp--- ILFS line tripped again at 06:05 hrs on 05-02-2015 due to PLCC
mal-operation.
End to end testing of PLCC is desired for confirming the correctness of PLCC system.
By 27.02.2015, end-to-end testing of PLCC shall be completed by NLC and SR-II of
PGCIL.
Main 2 distance relay settings shall be revised at NLC-1 Exp by 7th March failing which
the NLC-1 Exp – IL&FS line would be kept open till the completion of the same.
DEF time setting to be revised to 1.1 sec at IL&FS.
PGCIL (SR-II) shall revise the time setting of Zone-3 at Pondicherry (which is 0.8 sec) to
1.0 sec.
Recommendations:
IL&FS, NLC -1 Exp & PGCIL (SR-II) to furnish action taken report on the
recommendations given by SRPC Committee in their meeting held at IL&FS on 19-
02-2015 to SRPC.
4 Tripping of
400/220 kV ICT-3
at Trichur
03-02-2015 at
00:26
ICT tripped due to operation of REF
protection
GI-2
Deliberations:
KSEB:
ICT # 3 tripped due to Restricted Earth Fault Relay operation. This was initiated because
of the heavy arcing from the three pole isolator just before the tripping. Later the Isolator
was inspected thoroughly and it was noticed that there was a gap of about 10 cm between
the male and female contacts.
There was heavy wind blowing across the yard. It was suspected that the Isolator might
have got opened up due to this heavy wind.
It was suspected that corona plates at the tip of male/female contacts could be the cause of
Annexure-III
11
5 Tripping od 400 kV
NLC EXP- ILFS line
05-02-2015 at
06:05 hrs
Line tripped due to direct trip receipt from
IL&FS
GI-2
As per FIR of NLC1 Exp, this line tripped due to DT receipt from IL&FS. Whereas from the
NLC 1 Exp’s DR, no fault seemed to have taken place on this line. Also no DT was received
from IL&FS. (no variation in I and V are observed – ref: DR of NLC 1 Exp).
Recommendations:
IL&FS, NLC 1 Exp & PGCIL (SR-II) to furnish the action taken report on the
recommendations given by SRPC Committee in their meeting held at IL&FS on 19-
02-2015 to SRPC.
6 Tripping of 400kV
Coastal Energen
(CEPL)---NTPL line
07-02-2015 at 01:07
hrs and at 00:08hrs
on 08-02-2015
B-phase to earth fault had occurred in
Line during both instants. As seen from
D.R of Coastal Energen distance relay
sensed fault in zone-2 and earth fault
protection had operated which resulted
in tripping of line.
GI-2
Deliberations:
B-phase to earth fault occurred at NTPL station compound (due to insulator flash-over at
NTPL). But no carrier was sent to CEPL even though the distance relay sensed the fault
and A/R is in service.
CEPL sensed the fault in Zone-2. But even before Zone 2 operation, EFR operated at
CEPL end and sent DT to NTPL.
NTPL end CB tripped due to carrier receipt from CEPL.
SRLDC:
Back up Earth fault relay (EFR) to be blocked when distance protection relay (DPR) is
sensing the fault.
.
PGCIL:
Due to severe pollution and fog at NTPL (coastal area), Insulators cleaning is being
undertaken along with replacing the faulty insulators.
Recommendations:
PGCIL to carry out hot-line washing regularly as NTPL is in highly polluted location.
opening of the contacts by exerting pressure on them. It was decided to review the corona
plates and replace them by corona rings.
It was also being planned to have locking type isolator contacts that would ensure not
opening of the contacts due to heavy wind.
Corrective Action Taken:
The transformer was charged after testing all the parameters and cleaning the
carbonized portion of the isolators.
The matter has been taken up with M/s G.R.Power Switchgear Ltd, the OEM for
studying the exact reason for opening of the isolators and also for design change to be
incorporated in isolators to avoid the recurrence of this kind of incidents in future.
Annexure-III
12
7 Tripping of ICT-1,2&3 at
Hoody substation
07-02-2015 at
17:15 hrs &
19:45 hrs
Arcing observed in 220kV switchyard.
ICT’s were hand tripped load loss was
400MW
GI-2
Deliberations:
KPTCL:
Set-Up:
There are 3x500 MVA, 400/220 kV ICTs and their 220 kV sides are connected to double
bus system; the 220 kV buses are named ‘north’ and ‘south’. There is a 220 kV bus
coupler through which on-load transfer of feeders and transformers (between north and
south buses) are being carried out. 220 kV side is shared by old and new sub stations.
There are 6x100 MVA transformers on old bus.
Cause of of tripping at 17.15 hrs:
LC for ICT-1 was availed to attend the hot spots on 220 kV north bus isolator; after
completion of the work, ICT-1 was connected to south bus.
220 kV bus coupler was charged in order to connect ICT-3, HAL-1 and HAL-2
feeders on north bus.
ICT-3 was transferred from south bus to north bus. Then while trying to transfer
HAL-1 feeder from south bus to north bus, heavy arc was observed that damaged the
north bus isolator contacts of HAL-1 feeder.
It was suspected that bus coupler was open while closing the HAL-1 isolator which
had to carry all the current of ICT-3 from north bus that resulted in heavy arc. All the
feeders and ICTs were hand-tripped to contain the arc.
The bus-coupler control is with the old substation control room and it’s status is not
known to the workmen who are operating the HAL isolators.
Cause of tripping at 19.45 hrs:
Similarly, heavy arc was witnessed while opening HAL-2 north bus isolator. Here
also the open bus coupler during the operation is suspected. ICTs and 220 kV feeders
were hand tripped to contain the arc.
During the disturbance, Bangalore metro was affected for 5 minutes.
Inter lock between bus isolators and bus coupler CB, which is possible under SAS
scheme, is not present at Hoody S/S.
Corrective Action Taken: Strict instructions have been issued to workmen to check the status of the bus coupler
and ensure its closed position while carrying out bus transfer operations.
It was found out that bus coupler CT was with 600/1 A setting which could have
tripped during the transfer operations. Now CT is changed to 900/1 A ratio.
SRLDC:
There has to be interlock between bus coupler CB and feeder isolators so that bus isolators
cannot be operated on-load unless bus coupler CB is closed.
KSEB:
The tripping of bus coupler due to overload (tie current flow) is not recommended.
Since the rating of the bus coupler is based on line loading, its rating should be sufficient
to carry bus loading to avoid unwanted tripping of the system.
Annexure-III
13
8 Tripping of HVDC
Talcher-Kolar pole-2
10-02-2015 at 7:37
hrs
Pole-2 tripped due to ESOF from
Talcher end
GI-2
Deliberations:
It was informed that due to water clogging, there was some differential pressure variation
which inhibited proper working of the pumps at Talcher HVDC.
Pole-2 tripped due to Emergency Switch off (ESOF) from Talcher end due to valve cooling
problem.
HVDC pole-1 went into Metallic Return mode and flow on Pole-1 was 854MW after tripping
of Pole-2.
As there was loss of power, SPS-1 & 3 signals were generated at Kolar end and sent to SR-
Constituents to carry out load shedding.
Load relief of 1457 MW was obtained due to above SPS operation.
SRLDC:
Talcher end Sequence of Events (SOE) has to be obtained and Talcher could be given user id
and password to upload the FIR, DR, EL, Trip analysis reports on SRLDC’s web based
monitoring system.
SRPC:
Similar incident happened on 16-12-2014, and was discussed in the 39th meeting of PCSC;
when PGCIL was asked to carry out testing of the pumps and submit a report to the PCSC
forum, which was still awaited.
,
Recommendations:
PGCIL to test the pumps at Talcher HVDC during pole shut-down and submit the report
to PCSC forum.
9 Tripping of 400KV
Jeypore-Gajuwaka line-
1&2 and HVDC Pole-
1&2 at Gajuwaka
10-02-2015 at
16:24 hrs
Tripped due to disturbance in southern
Odisha.
GI-2
Deliberations:
It was noted that owing to disturbance in Southern Odisha, severe voltage fluctuations
(100kV to 450kV) experienced over Jeypore – Gajuwaka 400 kV D/C line.
Due to this, HVDC Pole-2 tripped due to “Low DC voltage trip” and Pole-1 tripped due to
“Valve winding AC under voltage fault”. The poles were carrying 300 MW each at the
time of tripping.
Subsequently, Jeypore - Gajuwaka line tripped at Jeypore end on operation of Over
Voltage relay, Stage II protection; Gajuwaka-end CBs tripped due to receipt of DT from
Jeypore end.
It was also reported that 400kV Indravati-Rengali, 400 kV Jeypore-Bolangir, 400kV
Jeypore-Indravati lines in eastern region tripped on over voltage.
10 Tripping of Hassan-
UPCL line-2
12-02-2015 at 15:57
hrs
Line tripped due to high resistance fault
in B-phase. DEF picked up at hassan
end and DT was sent to UPCL. DEF
protection did not pick up at UPCL
GI-2
Annexure-III
14
Deliberations:
The line tripped due to high resistance fault in B-phase. Directional Earth fault (DEF) relay
picked up at Hassan end and DT was sent to UPCL.
Distance or DEF protection did not sense the high resistance fault at UPCL.
KPTCL:
It was a slow developing fault.
At UPCL, DEF relay current setting is 600A (primary) and 0.3 A (secondary) on 2000/1 A
CT. Once it picked up it will wait for 1.5 seconds (IDMT) before issuing trip command.
Usually the operation order of the relays (in increasing time) is: Zone-3, A/R dead-time,
Pole Discrepancy and DEF.
SR-II:
DEF current setting at Hassan is 200A (primary) on 3000/1 CT; time dial setting is at 0.6
(normal inverse). If current through the neutral is above 600A, it will trip after 3 seconds.
SRLDC:
Need to review the Directional Earth fault settings at both ends.
The DEF settings at both the station should be kept same.
DEF pick up settings at UPCL to be reviewed in coordination with KPTCL.
Recommendations:
UPCL to revise their DEF relay settings.
11 Tripping of 400kV
BTPS - Hiriyur line-2
13-02-2015 at
17:07hrs
Line tripped at BTPS end only. GI-2
Deliberations:
BTPS-Hiriyur Line 2 tripped at BTPS end only; The line was holding from Hiriyur S/S.
86 A and 86B relays operated at BTPS tripping the line. But no DT was sent to Hiriyur.
Suspected case of PLCC mal-operation.
KPCL:
Some PLCC works were going on at Hiriyur station.
Recommendations:
KPCL to furnish remedial measures taken to prevent recurrence of PLCC mal-operation at
BTPS.
12 Tripping of 400KV
Coastal-NTPL line
13-02-2015 at 22:54
hrs
Line tripped B-phase to earth fault and
later 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.
GI-2
Deliberations:
Annexure-III
15
B-phase to earth fault occurred at NTPL compound. This led A/R to open B phase CB.
However at CEPL end, the fault was sensed in Zone-2, and a 3-phase trip was given by
distance relay; but only Y & B poles of the breaker got opened as a result; the R-pole of the
breaker opened on operation of Pole Discrepancy relay.
Due to persistent fault, the R and Y poles of the breaker opened on R-Y phase fault at NTPL
end.
Single phase Auto-reclosure was unsuccessful at CEPL end.
SRLDC:
Need to check Auto reclosure scheme at CEPL end.
SRPC:
Need to check working of CB at CEPL end.
Recommendations:
CEPL to check A/R scheme at their end.
13 Tripping of 400kV
NTPL-Tuticorin
pooling station
13-02-2015 at 23:12
hrs
Line tripped on R-phase to earth fault at
22:53 hrs. Line auto reclosed at
Tuticorin pooling end and holding. At
23:12 line tripped on B-phase to earth
fault in zone-2 time.
GI-2
14 Tripping of 400kV
NTPL-Tuticorin
pooling station
14-02-2014 at 1:41
hrs
B-phase to earth fault had occurred and
line auto reclosed at 01.09 Hrs and
holding from Tuticorin PS end and line
was and up hand tripping at 01.44.
GI-2
15 Tripping of 400kV
NTPL-Tuticorin
pooling station
14-02-2014 at 6:55
hrs
Line tripped on B-phase to earth fault.
Line did not reclose at NTPL end
GI-2
Deliberations:
MS suggested that NTPL to be invited to meeting to discuss the trippings involving NTPL
station.
PGCIL:
Due to severe pollution and fog at NTPL (coastal area), Insulators cleaning is being
undertaken along with replacing the faulty insulators.
Recommendations:
PGCIL to carry out hot-line washing regularly as NTPL is in highly polluted location.
NTPL to review A/R scheme at their end.
Madurai NTPL
Coastalgen
(CEPL)
Tuticorin Pooling Station
Annexure-III
16
16 Tripping of 400 kV
NEYVELI TS 2 -
PUGALUR
15-02-2015 at 18:38
hrs
Line tripped at pugalur end due to direct
trip receive
GI-2
Deliberations:
The line got tripped at Pugalur end due to the DT receipt.
However, there was no fault at NLC TS-2.
PLCC mal-operation was suspected at Pugalur.
Recommendations:
PGCIL to check the protection coupler of PLCC system at Pugalur end.
III Tripping events due to PLCC Mal-operation:
Sl. No.
Element Date & Time
Reason PCSC Deliberations
1 Tripping of 400kV
Gooty-Somanahalli
line
20-01-2014
at 11:44 hrs
line tripped at Gooty
end only and was
holding from
Somanahalli end line
Recommendations:
PGCIL to furnish remedial
measures taken.
PGCIL to properly tune PLCC
panels. 2 Tripping of 400kV
Udumalpet-Palakad
line-1& 400
Udumalpet-Arasur
line-2
09-02-2015
at 9:50hrs PLCC of Udumalpet-
Arasur-2 mal-operated Recommendations:
PGCIL to furnish remedial
measures taken.
PGCIL to properly tune PLCC
panels.
IV. Tripping events due to failure/ non-operation of Auto-Reclose (A/R) during
Transient fault:
S.No Element Date &
Time Reason PCSC Deliberations
1 400 kV Hyderabad -
Malkaram 24-01-2015
at 06:34 hrs Line tripped on R-
phase to earth fault.
Line did not auto
reclose at Hyderabad
end.
PGCIL: CB locked-out due to low air
pressure.
2 400kV Tuticorin PS-
NTPL 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.
Recommendations: NTPL to check A/R scheme at
their end.
3
400 kV RAICHUR -
MUNIRABAD 17-02-2015
at 07:05hrs Line tripped on R-
phase to earth fault.
Line did not auto
reclose at Raichur
end.
KPCL:
Micromho relay will be
replaced by Siemens make
numerical relay.
Annexure-III
Pending Remedial Measures/ Action taken
for the Critical Tripping Incidents (as on 12.03.2015)
SN Element Name Outage date/time
Revival date/time
Reason for Outage Remedial Measures/ Action taken
1 220 kV AMBEWADI - PONDA 1 06-01-2015/ 12:01:00
06-01-2015/ 12:20:00
TRIPPED ON EARTH FAULT To-be-discussed
2 HVDC BHADRAVATHI POLE 2 08-01-2015/ 09:57:00
08-01-2015/ 10:16:00
NON VALID TAP CODE To-be-discussed
3 220 kV NEYVLI - BAHOOR 11-01-2015/ 15:42:00
11-01-2015/ 17:26:00
R-N FAULT To-be-discussed
4 400 kV VIJAYAWADA - NELLORE 1 22-01-2015/ 11:39:00
22-01-2015/ 11:56:00
DIFFERENTIAL PROTECTION OPERATED
To-be-discussed
5 400 kV SRISAILAM-MAMIDIPALLI 2 23-01-2015/ 16:10:00
23-01-2015/ 19:28:00
BUS2 DEAD WHILE CONVERTING SSLM GEN TO COND. MODE
To-be-discussed
6 400 Kv SATTENAPALLI - SRISAILAM 1 23-01-2015/ 16:10:00
BUS2 DEAD WHILE CONVERTING SSLM GEN TO COND. MODE
To-be-discussed
7 400 kV NLC EXP- ILFS 24-01-2015/ 13:15:00
24-01-2015/ 16:52:00
TRIPPED ON R-N FAULT To-be-discussed
8 400 kV NLC EXP- ILFS 27-01-2015/ 10:05:00
27-01-2015/ 11:20:00
CONTROL CKT PROBLEM @ ILF &S To-be-discussed
9 400 kV RAMAGUNDAM - N'SAGAR 1 03-02-2015/ 16:23:00
03-02-2015/ 16:40:00
LR PRV OPERATED @ NSR To-be-discussed
10 400 kV NLC EXP- ILFS 05-02-2015/ 06:05:00
05-02-2015/ 07:14:00
PLCC MALOPERATION AT NLC 1 EXP
To-be-discussed
11 400 Kv COASTAL - TTRNPS 07-02-2015/ 01:07:00
DISTANCE PROTECTION ACTED To-be-discussed
12 400 Kv COASTAL - NTPL 08-02-2015/ 00:08:00
B-N FAULT To-be-discussed
13 400 Kv UDUMALPET - PALLAKAD 1 09-02-2015/ 09:50:00
09-02-2015/ 09:58:00
PLCC MALOPERATION To-be-discussed
Annexure-IV
14 400 Kv UDUMALPET - PALLAKAD 2 09-02-2015/ 09:50:00
09-02-2015/ 09:58:00
PLCC MALOPERATION To-be-discussed
15 400 Kv NTPL - TTRNPS 09-02-2015/ 03:17:00
TRIPPED DUE TO HEAVY ARCING AT NTPL END
To-be-discussed
16 HVDC GAJUWAKA POLE 2 10-02-2015/ 16:25:00
10-02-2015/ 18:49:00
SOUTHERN ORISSA DISTURBANCE To-be-discussed
17 400 kV JEYPORE - GAZUWAKA 1 10-02-2015/ 16:24:00
10-02-2015/ 17:17:00
SOUTHERN ORISSA DISTURBANCE To-be-discussed
18 400 kV JEYPORE - GAZUWAKA 2 10-02-2015/ 16:24:00
10-02-2015/ 20:20:00
SOUTHERN ORISSA DISTURBANCE To-be-discussed
19 HVDC GAJUWAKA POLE 1 10-02-2015/ 16:24:00
10-02-2015/ 17:54:00
SOUTH ORISSA DISTURBANCE To-be-discussed
20 400/220 kV ICT-2 AT HIRIYUR 11-02-2015/ 14:56:00
11-02-2015/ 14:57:00
TRIPPED DUE TO NTAMC WORK To-be-discussed
21 400 Kv NTPL - TTRNPS 13-02-2015/ 23:12:00
14-02-2015/ 00:15:00
B - N FAULT To-be-discussed
22 400 Kv HIRIYUR-BTPS 2 13-02-2015/ 17:07:00
13-02-2015/ 17:20:00
TRIPPED AT BTPS To-be-discussed
23 400 Kv COASTAL - NTPL 13-02-2015/ 22:54:00
REASON AWAITED To-be-discussed
24 400 Kv NTPL - TTRNPS 14-02-2015/ 01:41:00
DISTANCE PROTECTION To-be-discussed
25 400 Kv NTPL - TTRNPS 14-02-2015/ 06:55:00
14-02-2015/ 08:49:00
DISTANCE PROTECTION To-be-discussed
26 220 kV PONDYCHERRY- BAHOOR 15-02-2015/ 11:20:00
15-02-2015/ 14:23:00
TRIPPED ON OVER CURRENT To-be-discussed
27 400 kV NEYVELI TS 2 - PUGALUR 15-02-2015/ 18:38:00
15-02-2015/ 18:51:00
TRIPPED DUE TO PLCC MALOPERATION
To-be-discussed
28 220 kV NEYVLI - BAHOOR 15-02-2015/ 11:20:00
15-02-2015/ 13:13:00
TRIIPED ON OVER CURRENT To-be-discussed
29 400 kV TALAGUPPA - NEELAMANGALA 18-02-2015/ 16:04:00
DISTANCE PROTECTION To-be-discussed
30 400 kV MUNIRABAD - GUTTUR 18-02-2015/ 07:40:00
18-02-2015/ 12:44:00
B-N FAULT To-be-discussed
Annexure-IV
31 400 kV GHANAPUR - MAMIDIPALLY 18-02-2015/ 12:12:00
18-02-2015/ 12:12:00
PLCC MALOPERATION To-be-discussed
32 400 kV KHAMMAM - KALPAKKA 1 18-02-2015/ 12:58:00
18-02-2015/ 14:28:00
PLCC MALOPERATION To-be-discussed
33 400 Kv COASTAL - NTPL 19-02-2015/ 16:53:00
19-02-2015/ 17:17:00
TRIPPED DUE TO LOW VOLTAGE To-be-discussed
34 400 Kv COASTAL - TTRNPS 19-02-2015/ 16:37:00
19-02-2015/ 16:56:00
DT RECIEVED AT COSTAL END To-be-discussed
35 220 Kv CHIKKODI - MUDUSHINGI 20-02-2015/ 06:40:00
20-02-2015/ 07:36:00
TRIPPED DUE TO R-PH FAULT To-be-discussed
36 400 kV MALKARAM - HYDERABAD 20-02-2015/ 10:37:00
20-02-2015/ 10:52:00
PLCC MALOPERATION To-be-discussed
37 220 Kv CHIKKODI - TALANDGE 20-02-2015/ 06:40:00
20-02-2015/ 08:07:00
TRIPPED AT CHIKKODI END To-be-discussed
38 400 kV KAIGA - GUTTUR 2 21-02-2015/ 14:18:00
21-02-2015/ 18:47:00
B-N FAULT To-be-discussed
39 400 kV MUNIRABAD - GUTTUR 21-02-2015/ 00:26:00
21-02-2015/ 00:43:00
DT RECIEVED To-be-discussed
40 400/220 kV ICT-1 AT NEELAMANGALA 22-02-2015/ 16:58:00
22-02-2015/ 18:17:00
TRIPPED DUE TO B-PH LA FAILURE To-be-discussed
41 220 kV KANIAMPET - KADAKOLA 22-02-2015/ 16:25:00
22-02-2015/ 16:51:00
DISTANCE PROTECTION ACTED To-be-discussed
42 400/220 Kv ICT-2 AT BIDADI 22-02-2015/ 16:58:00
22-02-2015/ 20:15:00
TRIPPED DUE TO TRANSIENT EART FAULT DUE TO TRIPPING OF NLM ICT
To-be-discussed
43 HVDC TALCHER - KOLAR POLE 1 AT TALCHER
23-02-2015/ 15:37:00
23-02-2015/ 15:55:00
TRIPPED WHILE TAKING DC FILTERS To-be-discussed
44 400 kV JEYPORE - GAZUWAKA 2 23-02-2015/ 13:34:00
23-02-2015/ 21:46:00
DT RECIEVED FROM JEYPORE To-be-discussed
45 HVDC GAJUWAKA POLE 2 23-02-2015/ 13:34:00
23-02-2015/ 18:03:00
DUE TO TRIPPING OF INCOMING LINES
To-be-discussed
46 400 Kv NTPL - TTRNPS 23-02-2015/ 04:42:00
INSULATOR FLASHOVER To-be-discussed
47 400 Kv NTPL - TTRNPS 24-02-2015/ EARTH FAULT To-be-discussed
Annexure-IV
04:30:00
48 400 kV TALAGUPPA - NEELAMANGALA 24-02-2015/ 11:11:00
24-02-2015/ 11:16:00
DISTANCE PROTECTION ACTED To-be-discussed
49 765/400 kV ICT-1 at RAICHUR 25-02-2015/ 18:32:00
25-02-2015/ 20:32:00
MALOPERATION OF WINDING TEMPERATURE INDICATION
To-be-discussed
50 400 kV N'SAGAR - CUDDAPPA 2 26-02-2015/ 17:23:00
26-02-2015/ 18:06:00
Y-N FAULT To-be-discussed
51 400/220 Kv ICT-1 AT SATTENAPLLI 26-02-2015/ 10:19:00
26-02-2015/ 11:30:00
GROUP - A PROTECTION OPERATED To-be-discussed
52 400/220 kV ICT-3 AT GAJWEL 27-02-2015/ 02:32:00
27-02-2015/ 02:53:00
TRIPPE ON MALOPERATION To-be-discussed
53 400 kV HIRIYUR - NELAMANGALA 2 27-02-2015/ 17:19:00
27-02-2015/ 17:21:00
DT RECEIVED AT NLM To-be-discussed
54 400 kV JEYPORE - GAZUWAKA 1 28-02-2015/ 00:19:00
28-02-2015/ 01:19:00
TRIPPED AT GAJUWAKA END ON R-N FAULT
To-be-discussed
55 400 kV NLC EXP- ILFS 28-02-2015/ 19:17:00
28-02-2015/ 20:50:00
TRIPPED AT NLCTS1EXP END To-be-discussed
56 220 Kv CHIKKODI - MUDUSHINGI 01-03-2015/ 03:37:00
BUS DEAD AT MUDUSHINGI END To-be-discussed
57 220 Kv CHIKKODI - TALANDGE 01-03-2015/ 03:37:00
BUS DEAD AT TALANDGE END To-be-discussed
58 220 kV AMBEWADI - PONDA 1 01-03-2015/ 04:21:00
01-03-2015/ 04:57:00
Y - N FAULT To-be-discussed
59 400 Kv COASTAL - NTPL 02-03-2015/ 03:51:00
B - N FAULT To-be-discussed
60 400/220 kV ICT-1 AT TRICHUR 03-03-2015/ 17:02:00
03-03-2015/ 17:54:00
BUS BAR PROTECTION OPERATED AT MADAKATHRA
To-be-discussed
61 400/220 kV ICT-2 AT HOODY 03-03-2015/ 23:44:00
04-03-2015/ 04:27:00
TRIPPED DUE TO OIL SURGE RELAY To-be-discussed
62 400/220 kV ICT-2 AT TRICHUR 03-03-2015/ 17:02:00
03-03-2015/ 17:55:00
BUS BAR PROTECTION OPERATED AT MADAKATHRA
To-be-discussed
63 400/220 kV ICT-3 AT HOODY 03-03-2015/ 23:44:00
04-03-2015/ 03:43:00
BUCCHOLZ RELAY OPERATED To-be-discussed
Annexure-IV
64 400/230 kV ICT-2 AT SALEM 03-03-2015/ 21:30:00
04-03-2015/ 00:17:00
TRIPPED DUE TO RELAY MALOPERATION
To-be-discussed
65 765/400 kV ICT-1 at RAICHUR 03-03-2015/ 12:23:00
03-03-2015/ 13:26:00
TRIPPED To-be-discussed
66 400 Kv RAICHUR PG - GOOTY 1 04-03-2015/ 12:31:00
04-03-2015/ 12:45:00
TRIPPED DUE TO NTAMC WORK To-be-discussed
67 400/230 kV ICT-2 AT SALEM 04-03-2015/ 21:45:00
OIL SURGE RELAY OPERATED To-be-discussed
68 220 kV UPPER SILERU - BALIMELA 04-03-2015/ 08:00:00
LBB OPERATED AT UPPER SILERU To-be-discussed
69 400 Kv SATTENAPALLI - SRISAILAM 2 04-03-2015/ 14:25:00
04-03-2015/ 15:08:00
R-N FAULT To-be-discussed
70 400/230 kV ICT-2 AT SALEM 04-03-2015/ 19:55:00
04-03-2015/ 21:11:00
OIL SURGE RELAY OPERATED To-be-discussed
71 400/220 kV ICT-1 AT MUNIRABAD 08-03-2015/ 19:41:00
08-03-2015/ 20:52:00
DEF OPERATED To-be-discussed
72 400 kV DICHIPALLY - RAMAGUNDAM 09-03-2015/ 00:56:00
B-N FAULT IN ZONE 1 To-be-discussed
73 400/220 kV ICT-2 AT RAICHUR 09-03-2015/ 06:36:00
09-03-2015/ 13:07:00
REASON AWAITED FROM KPTCL / RCR
To-be-discussed
74 400/220 kV ICT-2 AT MAHABOOB NAGAR 09-03-2015/ 07:57:00
09-03-2015/ 19:16:00
RESTRICTED EARTH FAULT To-be-discussed
75 400 kV MAHABOOB NAGAR - RAICHUR 09-03-2015/ 06:36:00
09-03-2015/ 07:55:00
REASON AWAITED FROM KPTCL / RCR
To-be-discussed
76 400 Kv RAICHUR - RAICHUR PG 1 09-03-2015/ 06:36:00
09-03-2015/ 08:18:00
REASON AWAITED FROM KPTCL / RCR
To-be-discussed
77 400 Kv RAICHUR - RAICHUR PG 2 09-03-2015/ 06:36:00
09-03-2015/ 08:02:00
REASON AWAITED FROM KPTCL / RCR
To-be-discussed
78 400 kV MADURAI - PUGALUR 1 10-03-2015/ 19:18:00
10-03-2015/ 20:20:00
TRIPPED AT PGLR END DUE TO MAIN CB FAILURE ALARM
To-be-discussed
Annexure-IV
Meeting
No / Index
Details of Event Date Reason PCSC Recommendations Utility Responsible
for implementation
Status of Recommendations
as on 13.03.2015
Remarks
39/III/1 Tripping of 400kv
VTPS-Satenapalli line-
1 &2
10, 11, 13, 14,15
Dec 2014 voltage.
and grading in over voltage
protection needs to be verified.
PCSC forum recommended APTRANSCO to check up the
drop off to pick up ratio of the Overvoltage relay and correct
it (if needed).
APTRANSCO/
APGENCO
APTRANSCO informed vide their e-mail dated
27.02.15 that the issue pertains to APGENCO.
Pending
40/IV/2 400 kV HYDERABAD -
KURNOOL line
07-01-2015
at 6:17 hrs
Line tripped on Rphase to earth
fault. A/R lock out
observed in E.L of Hyderabad
end
APTRANSCO was requested to check up the A/R feature at
both the ends and submit the remedial measures to the PCSC
forum.
APTRANSCO Yet to be informed Pending
30/I/A RTPS Tripping incidents
and the Spl meeting held
at RTPS on 13th and 14th
March 2014
Mar-14 Spl meeting held at RTPS on
13th
and 14th
March 2014
The PCSC forum recommended for replacement of existing
electromechanical relays with Numerical relays.
KPCL 1. e- Tender folated for the retrofit of existing static
relays with Numerical version for lines
M.nagar,M.bad,ICT-1 & 2 -Technical Bid opened
& price bid yet to be opened.
2. Retrofit of existing bus bar (CAG-34) with
numerical version -Budgetetory offers obtained and
is under process.
3. Order placed on M/s Siemens to replace relays.
The work will be Completed by May - 2015.
Pending
33/II/3 400kV
Hiriyur-BTPS line-2
22-05-14 &
23/05/2014
B phase to ground fault had
occurred in line and line auto
reclosed at Hiriyur end but
failed to reclose at BTPS end.
The PCSC forum requested KPCL to enable the A/R feature at
RTPS end before next PCSC meeting (i.e. 31st July, 2014.
KPCL 1. A/R for 220kV lines enabled already.
2. Shtu down of lines availed to commission the
auto reclosing schme fro 400 kV line at BTPS.
3. A/R shall be enabled in next shutdown
Pending
34/III/1 400kV
Raichur-BTPS line
26-06-2014 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. Shtu down of lines availed to commission the
auto reclosing schme fro 400 kV line at BTPS.
3. A/R shall be enabled in next shutdown
Pending
Pending Implementation of PCSC Recommendations (30th to 40th)
Andhra Pradesh
Telangana
Karnataka
Annexure-V
38/GD/3.5 GD-1 at Kadra and
Kodasalli hydro power
station
13-11-2014 at
19:31hrs
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.
2. The PCSC forum requested KPCL to submit the
implementation status of PSAG-10 recommendations within a
week’s time.
KPCL All the recommendations of PSAG - 10 are
completed except the following pending issue:
i)e-NIT floated on 28.07.2014 for procurement of
Numerical distance relays & GPS. Bid evaluation
is under progress. The work will be completed by
December - 2015. Hower, as per the
recommendations of PSAG, Relays were
temporarily rearranged, replaced and wired up.
testing & commissioning shall be completed with
the assistance of KPTCL by March 1st week ,
2015.
Pending
34/I/6 400/220 kV ICT-1 & 2 at
MUNIRABAD
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) .
2. Settings for main distance protection & Overcurrent
protection shall be examined and reviewed.
3. Time synchronization of the Substation shall be ensured.
4. Correct DR shall be submitted to the SRLDC for trip analysis.
KPTCL Management approval is obtained for taking up the
work of providing bus bar protection to 220kV
buses at Guddadahally (Munirabad) Sub Station
along with replacement of 3 core/age old CTs of
220kV bays belong to KPTCL.
Under implementation
Pending
38/GD/3.1 GD-1 at Mahalingapura
Substation of KPTCL
25-10-2014 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.
1. PCSC forum recommended KPTCL to replace the old static
distance protection relays with numerical relays.
2. PCSC forum also requested KPTCL to provide a broken
conductor alarm indication in Control Room.
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 Yet to be informed Pending
38/GD/3.2 GD-1 at Guttur
Substation of KPTCL
05-11-2014 at
11:42 hrs
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 of
pending recommendations of:
1. Protection Audit (Phase-I & Phase-II)
2. PSAG-4, PSAG-5, and PSAG-8
KPTCL Yet to be informed Pending
39/I/5 Tripping of 400/220kV
ICT-2 at Hoody
substation of KPTCL
01-12-2014 Suspected mal-operation of
220kV side Rphase
over current relay
1. PCSC forum recommended KPTCL to replace the relay 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.
KPTCL Yet to be informed Pending
39/I/8 Tripping of 220kV
Chikodi-Talandage&
220kV Chikodi-
Mudshingi lines
01-12-2014 Talandge line tripped at
Chikkodi
end on Back up protection.
Meanwhile Mudashinge line
tripped
at Maharastra end on
DPR,Zone-2.
KPTCL was requested to get tripping report details from the
stations (i.e. Talandage, Mudashinge and Chikodi) and furnish
them to PCSC forum.
KPTCL Yet to be informed Pending
Annexure-V
39/I/10 Tripping of
Neelamangala- Hoody
Ckt-1&2 along with
Hoody ICT-2
13-12-2014 It was reported that bus bar
protection
got operated at Hoody
substation.
Reason for the operation of bus bar protection relay and
remedial measures shall be submitted to PCSC forum.
KPTCL Yet to be informed Pending
40/I/1 GD-1 at 220kV
Ambewadi Station of
KPTCL
22-12-2014 at
21:22 hrs
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
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 check up the ICTs protection system for
finding the cause of not tripping for the line fault (through fault)
and submit the remedial measures.
3. KPTCL shall provide the details of the tripping of Supa hydro
station connected downstream from 110 kV bus.
KPTCL Yet to be informed Pending
40/IV/1 220kV Sedam-
Tandur line
20-12-2014
at 22:20 hrs
Line tripped on Yphase to earth
fault from both the ends
KPTCL was requested to explore the possibility of providing
A/R feature to this line and submit the remedial measures to the
PCSC forum.
KPTCL Yet to be informed Pending
36/II/9 400kV Arasur-Mettur
Line I
29-09-2014 Mettur S/s to Enable A/R Scheme. TANTRANSCO 1. During the 38th PCSC meeting, TANTRANSCO
informed that the Auto Reclosing facility would be
enabled within 15 days.
2 A/R scheme will be implemented after the
commissioning of 400 kV Thiruvalam Line-I & II.
Pending
37/II/3 400kV Mettur-Arasur
line-1
29-09-2014 Line tripped due to Y-Phase to
earth fault.
Line did not auto reclose as
Auto reclose scheme is kept in
non-auto mode.
A/R scheme to be enabled. TANTRANSCO 1. During the 38th PCSC meeting, TANTRANSCO
informed that the Auto Reclosing facility would be
enabled within 15 days.
2. A/R scheme will be implemented after the
commissioning of 400 kV Thiruvalam Line-I & II.
Pending
38/II/3 Tripping of 400kV
Mettur-Arasur line-2
22-10-2014 Line tripped on Rphase
to earth fault.
non-auto mode.
A/R feature to be enabled. TANTRANSCO 1. During the 38th PCSC meeting, TANTRANSCO
informed that the Auto Reclosing facility would be
enabled within 15 days.
2. A/R scheme will be implemented after the
commissioning of 400 kV Thiruvalam Line-I & II.
Pending
40/II/5 Tripping of 400kV
Kayathar-Karaikudi
line-2 at ICT-1,2&3 at
kayathar
07-01-2015 at
23:25 hrs
B-Ph CT of ICT-2 failed
resulting in operation of busbar
protection of Bus-2 and
differential protection of ICT-2
PCSC forum recommended TANTRANSCO to bring Bus-1
also into service to avoid complete outage of the 400kV bus at
Kayathar Substation.
TANTRANSCO Yet to be informed Pending
Kerala
Tamil Nadu
Annexure-V
38/GD/3.3 GD-1 at North Kerala
System
11-11-2014 at
02:02hrs
De-energization of 220kV bus
occurred at Areakode,
Madakathara and Shoranur.
1. The PCSC forum requested KSEB to submit the complete
analysis report of the Grid disturbance (i.e with DR, EL and
KSEB substation connectivity diagram) with the remedial
measures taken within a week’s time to SRPC Secretariat.
2. KSEB shall initiate measures for the following and report the
status to PCSC forum by next PCSC meeting:
(i) to rectify the trip coils at Shoranur on Areakode line CB
(ii) to check the healthiness of trip coils at all other stations
also.
(iii) to make LBB protection functional at Shoranur s/s.
(iv) to have trip circuit supervision provision with
annunciation, if feasible.
3. The status of implementation of SPS (meant for lines at
Madakathara S/S) shall be communicated to PCSC forum by
next PCSC meeting.
KSEB Pending
38/GD/3.4 GD-1 at North Kerala
System
12-11-2014 at
17:37 hrs
De-energization of 220kV bus
occurred at Areakode,
Kanhirode and Orkattery.
1. The PCSC forum requested KSEB to submit the complete
analysis report of the Grid disturbance (i.e with DR, EL and
KSEB substation connectivity diagram) with the remedial
measures taken within a week’s time to SRPC Secretariat.
2. Uniform settings for A/R feature shall be kept at both the ends
of the line.
3. Provision of alarm feature shall be considered for indicating
low pressure in Circuit Breaker system.
KSEB Pending
34/I/3 Tripping of HVDC
Bhadravati Pole-1 & 2
09-07-2014 As reported, pole-1&2 tripped
due to auxiliary supply failure.
1. The PCSC forum recommended PGCIL, SRTS-I take up the
issue with WRTS to submit the report as per IEGC guidelines.
2. SRLDC is also requested to write a letter to WRLDC to
submit the reports to SR also.
3. Based on the SRTS/SRLDC correspondences, SRPC would
take it up with WR and PGCIL if the issue is not getting
resolved.
4. Complete analysis of the faults and rectification/remedial
action taken to avert similar occurrence in the HVDC Back to
Back station shall be submitted.
PGCIL 1. Implementation of Tertiary Winding of ICT for
the auxilliary power supply is going to come up
which resolves this issue.
2. PGCIL informed that all issues would be
discussed during PSAG-11 visit.
Pending
PGCIL
Annexure-V
34/I/7 HVDC
BHADRAVATHI POLE
2
18-07-2014 As reported pole-2 tripped due
on 5th harmonic alarm.
1. Complete analysis of the faults and rectification/remedial
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.
PGCIL Yet to be informed Pending
39/I/1 Tripping of 400kV
Gooty-Somanahalli
22-11-2014 Line tripped due to
suspected PLCC
Mal-operation at Gooty
end.
Retrofitting of the relay or installation of Optical Fiber cable is
recommended by PCSC forum to PGCIL.
PGCIL Yet to be informed Pending
39/I/9 Tripping of HVDC
pole-2 of Talcher -
Kolar
16-12-2014
due to problem in valve cooling
system.
operated resulting in load
shedding of 1258
MW.
1. PGCIL shall test the pumps during pole shutdown and
submit the report to PCSC forum.
2. PGCIL shall conduct mock test for SPS signals to Kerala and
submit the feedback to PCSC forum.
PGCIL Yet to be informed Pending
40/II/1 Tripping of 400kV
Vijayawada-Gajuwaka
line
18-12-2014 at
18:33 hrs
Line tripped due to operation of
TEED protection at Gajuwaka
end due to opening of jumper of
Y phase CT.
PGCIL shall review the TEED protection at Gajuwaka end
and submit the details to PCSC forum.
PGCIL Yet to be informed Pending
37/I/9 Tripping of 400/220kV
ICT-1&2 at UPCL
04-10-2014 ICT-1&2 tripped during
transient fault in R-phase in
400kV Hassan-UPCL line-1
To avoid tripping of ICTs for line fault, UPCL is requested to
review the settings of ICT’s SEF relay and consider IDMT
setting instead of existing Definite Time setting.
UPCL It has been reported by UPCL that, the work of
review of relay coordination and setings for the
entire plant is given to M//s Alstom for entire
plant. UPCL has furnished the settings given by
M/s Alstom for verification. Revised settings will
be issued this week for implementation
Pending
40/II/8 Tripping of Unit-1 at
Kudankulam
14-01-2014 at
19:20 hrs
Y-phase Differential protection
of Generating transformer of
Unit-1 got operated which
resulted in tripping of Unit-1.
1. NPCIL, Kudankulam was recommended to submit all the
relevant reports of the above incident.
2. PCSC forum also requested NPCIL, Kudankulam to upload
all the reports (DR/EL/ FIR) of any incident in the SRLDC web
portal within 24 hrs of its occurrence.
NPCIL, Kudankulam Yet to be informed Pending
36/II/8 400kV Raichur-
Munirabad line
07-09-2014 B-phase to earth fault had
occurred in line.
Line auto reclosed at
Munirabad end and failed to
reclose at Raichur end.
KPTCL:
PD (pole discrepancy) time delay would be changed.
PGCIL /
KPTCL
Yet to be informed Pending
Others
Miscellaneous
Annexure-V
37/I/6 Tripping of 400KV
Hassan-UPCL line-2
25-09-2014 High resistance fault as the
fault ampere was very less i.e.,
0.6kA at Hassan end and nearly
0.9kA at UPCL end.
Back up earth fault protection
had operated at Hassan.
At UPCL end the high
resistance fault got converted
into a R ph-B-ph fault which
resulted in operation of distance
protection Zone-1.
The reason for non-picking up
of Back up earth fault at UPCL
needs investigation.
1. At UPCL end, unused zones of distance protection
(probably zone 5 to 8) shall be disabled.
2. At UPCL end, time synchronization between main-1 and
main-2 relays shall be ensured.
3. UPCL shall ensure time synchronization with Hassan
substation.
4. Reasons for non operation of back up protection at UPCL
for high resistance fault is to be submitted.
5. Reasons for not sending DT to UPCL by Hassan end is to
be submitted.
6. Settings of UPCL are to be reviewed and informed to PCSC
forum.
UPCL /
KPTCL
It has been reported by UPCL that, the work of
review of relay coordination and setings for the
entire plant is given to M//s Alstom for entire
plant. UPCL has furnished the settings given by
M/s Alstom for verification. Revised settings will
be issued this week for implementation.
Pending
38/II/2 Tripping of 400kV
Khammam- Kalpakka
line
11-10-2014 Line tripped on Yphase
to earth fault.
reclose at Khammam
end.
APTRANSCO and TSTRANSCO were requested to clear the
corridor jointly at the earliest.
PGCIL/
APTRANSCO/
TSTRANSCO
Yet to be informed. Pending
38/II/5 400kV Ramagundam-
Hyderabad line-4
27-10-2014
to earth fault.
reclose at Hyderabad
end due to
PLCCmal-operation.
Planned to replace the PLCC system within a week's time at
both the ends during the shutdown.
NTPC/ PGCIL Yet to be informed. Pending
38/III/10 Tripping of
400kV Hassan-
UPCL line-2
19-10-2014 operation of over voltage
protection at UPCL end
KPTCL and UPCL are requested to send the report with details
of the overvoltage tripping.
UPCL / KPTCL Yet to be informed Pending
39/I/2 Tripping of
400Kv Ghanapur-
Mamidipally
line
22-12-14
at 10:52 hrs,
24-12-14 at 11:32
hrs,
24-12-14 at 16:16
hrs
Due to PLCC Mal-operation at
HYD S/S end, DT received at
MMPLY end and line got
tripped.
PGCIL is requested check up with the manufacturer to resolve
the issue and submit remedial measures to PCSC forum.
PGCIL/ TSTRANSCO Yet to be informed. Pending
Annexure-V
1
The PSAG-10 members recommended to replace the Main I (Q21 static
Quadramho relay -SHPM 101) distance protection relays with Numerical relays
having DR and EL features.
e-NIT No. LOT/CEED/EE6/R&M/ Dist.Prot/1416 dtd:
28.07.2014 was floated through e-portal for Supply, Retrofit,
Testing & Commissioning of Numerical Distance protection
relays & GPS for Varahi, Gerusoppa, Kadra & Kodasalli
Power Houses of KPCL. Bid evaluation is under progress.
2The PSAG group also advised KPCL to test the Main II Relay (PZ1000
numerical relay) at the earliest .
Will be completed during last week of March 2015 in
coordination with KPTCL.
3
The PSAG group recommended to have a uniform Zone II time settings as
agreed in the Tripartite meeting of KPCL, KPTCL and Kaiga (NPCIL) held during
11th& 12th of December, 2013) in the Kaiga – Kali Complex.
Completed.
4
The Resistive reach of distance protection relay of Kadra – Kodasalli (both
ends), Kadra – Karwar I, Kadra – Karwar II (Kadra end), Kodasalli – Nagjheri I,
Kodasalli – Nagjheri II (both ends) lines to be increased so as to operate on high
resistance faults within the permissible limits . Since the present settings are
prone to under reach and initiating unwanted tripping at the their locations,
PSAG has recommended to suitably increase the resistive reach of all the lines.
PSAG advised KPCL to revise the settings at the earliest.
Completed.
Compliance to recommendations of Meeting of Protection system Analysis Group (PSAG-10) at Kadra, Kodasalli and
Kaiga held on 12th & 13th November 2014 for discussing the Grid Disturbancea occurred on 26.09.2014 and
05.10.2014
Sl. No. Recommendations KPCL Compliances- Status as on 23.02.2015
Page 1 of 2
Annexure-VI
Sl. No. Recommendations KPCL Compliances- Status as on 23.02.2015
5
PSAG recommended to make the carrier aided protection functional for 220kV
Kadra-Kodasalli, 220kV Kadra-Kaiga and 220kV Kodasalli-Kaiga lines. In
addition, since most of the faults are seen as high resistance fault, PSAG
suggested to revise the existing PUR to POR scheme for all the lines at Kali
complex.
e-NIT No. LOT/CEED/EE6/R&M/ Dist.Prot/1416 dtd:
28.07.2014 was floated through e-portal for Supply, Retrofit,
Testing & Commissioning of Numerical Distance protection
relays & GPS for Varahi, Gerusoppa, Kadra & Kodasalli
Power Houses of KPCL. Bid evaluation is under progress.
Hence work shall be taken up in coordination with KPTCL
after installation of new relays.
6
The PSAG group noted that most of the faults were in the ‘B’ Phase (of RYB) to
ground faults. The group observed that it may be due to thick vegetation below
Kadra – Kodasalli, Kodasalli - Kaiga line, Kadra – Kaiga line. Hence the PSAG
group members advised to have regular thorough line patrolling and clearing the
corridor (i.e. Right Of Way).
To be implemented by KPTCL
7
PSAG had recommended to have a uniform setting for the backup earth fault
protection (67N) provided through distance relay (i.e PZ1000) and separate back
up earth fault relay (CDD21 of English Electric, electro mechanical) immediately.
Completed.
8The PSAG group advised to disable the phase over current protection in
distance relays (i.e PZ1000 of CSPC make) immediatelyCompleted.
9
KPCL informed that installation of GPS for time synchronization of all relays and
other protection devices is under process. KPCL is requested to expedite the
same.
e-NIT No. LOT/CEED/EE6/R&M/ Dist.Prot/1416 dtd:
28.07.2014 was floated through e-portal for Supply, Retrofit,
Testing & Commissioning of Numerical Distance protection
relays & GPS for Varahi, Gerusoppa, Kadra & Kodasalli
Power Houses of KPCL. Bid evaluation is under progress.
10
It is suggested to check timings (opening and closing) on Kadra line CB test at
Kodasalli station periodically and the record of checking to be maintained in the
substation
Completed.
11
It was observed that Kodasalli – Nagjheri I & II lines were kept open at Nagjheri
end on 26.09.2014, 5.10.2014 & 14.10.2014 during bus dead conditions at
Kodasalli station. KPTCL (SLDC) is requested to clarify /review the issue
To be implemented by KPTCL/SLDC
12The DR and EL data of the line/unit tripping shall be made available for analysis
at station level / SLDC /SRLDC/SRPC level.Noted
Page 2 of 2
Annexure-VI
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Annexure-VII
Annexure-VII
Annexure-VII
Annexure-VIII
Annexure-VIII
Annexure-VIII
Format for intimating the Failure of Transmission line Towers
1. Name of Transmission line with voltage level:
2. Length of line (km):
3. Type of configuration:
[(S/C, D/C, S/C strung on D/C towers,
narrow base etc.)
4. Number of Towers and Type of Towers failed:
[suspension/ tension/dead end/special tower
/river crossing tower/ Powerline crossing/Railway Crossingetc.,
with / without extension
(indicatethe type & length of extension)]
5. Tower location No. with reference to nearest substation(indicate Name):
6. Name and size of conductor:
7. No. of sub-conductors per bundle and bundle spacing:
8. Number and size of Ground wire/OPGW (if provided):
9. Type of insulators in use(Porcelain / Glass / Polymer):
10. Configuration of insulators (I / V / Y / tension)
11. No. of insulators per string and No. of strings per phase:
12. Year of construction / commissioning:
13. Executing Agency:
14. Weather condition on the date of failure:
15. Terrain Category:
16. Wind Zone (1/2/3/4/5/6) and velocity of wind:
17. Details of earthing of tower (pipe type/ Counter poise):
18. Line designed as per IS:802 (1977/1995/any other code):
19. The agency who designed the line:
20. Any Special consideration in design:
21. Date and time ofoccurrence/discovery of failure:
22. Power flow in the line prior to failure:
23. Any missing member found before / after failure of towers:
24. Condition of foundation after failure:
25. Brief Description of failure:
[alongwith photographs(if available), other
related information like tower schedule,
newspaper clipping for cyclone / wind storm etc.]
26. Probable cause of failure:
27. Details of previous failure of the line / tower :
28. Whetherline will be restored on ERS or Spare tower will be used:
29. Likely date of restoration:
30. Present Status:
31. Details of any Tests carriedout after failure:
32. Any other relevant information:
Annexure-VIII
L1
Group -1 Feeder
1.Brindavan line at Peenya
2.Nelakaradanahalli line at Peenya ~130 MW
3.Widia line at Peenya
4.Telecom Layout line-1 & 2 at NRS
L2
Group -2 Feeder
1.D.G line-1,2 and 4 at Peenya ~150 MW
2.T.G Hally line at Peenya
3.Nandinilayout line at Peenya
Group -3 Feeder
1.Gokula line -1 and 2 line at Peenya
L3 2.Tr-1(20 MVA) & Tr-4(31.5 MVA) at Peenya
3.NRS-2 line at Peenya ~130 MW
4.Tr-1(20 MVA) & Tr-2(20 MVA) at NRS
5.Brigade at NRS
6. Vijayanagar at NRS
NELMANGALA-PEENYA
LINE-2
NELMANGALA-PEENYA
LINE-3
SPECIAL PROTECTION SCHEME FOR NELAMANGALA-PEENYA CORRIDOR as finalized by KPTCL
NELMANGALA-PEENYA
LINE-1
CURRENT IR OR IY GREATER
LINE CURRENT IY CURRENT IR OR IY OR IB GREATER
LINE CURRENT IR
LINE CURRENT IB
LINE CURRENT IY
LINE CURRENT IR
LINE CURRENT IB
CURRENT IR OR IY GREATER
CURRENT IR OR IY OR IB GREATER
DELAY OF 1 SECCURRENT >750A
CURRENT MAXOF L1,L2,L3
LINE CURRENT IY
LINE CURRENT IR
LINE CURRENT IB
TRIP GROUP-1 FEEDER
TRIP TR-3 HV BREAKER
TRIP GROUP-2 FEEDER
TRIP GROUP-3 FEEDER
CURRENT IR OR IY OR IB GREATER
CURRENT IR OR IY GREATER
DELAY OF 2.5 SEC
DELAY OF 2 SEC
Annexure-IX