Agenda Items For 27th PCC Meeting
Agenda Items For 27th PCC Meeting
Agenda Items For 27th PCC Meeting
c. Further information:
i. Substation Event Loggers output from 400/220 kV Bongaigaon, 400/220 kV
Balipara, 400/220 kV Misa, 400/132 kV Ranganadi, 220/132 kV BTPS,
400/220/132 kV Azara, 220/132 kV Samaguri, 400/220/132 kV Byrnihat &
400/132 kV Silchar sub-stations.
ii. Disturbance Recorder output of all elements mentioned as per Sl.No. 1.a.xiv to
1.a.xxvi.
iii. Quantum of feeder wise UFR based load shedding of each constituent.
iv. Whether any island formed in Upper Assam system.
2. Implementation of recommendation of the committee on Grid Disturbance of
Category V in NER on 25.07.14
A committee was constituted by POSOCO to enquire about the causes of the
disturbance in NER Grid occurred on 25.07.14. The committee submitted its report to
the PCC forum of NERPC (26 th PCCM). PCC forum of NERPC had requested
NERLDC to submit the remedial measures pertaining to the Grid Disturbance in NER
occurred on 25.07.14 to the constituents of NER. Letter No 56005-18 dtd 30.10.14 was
sent to all constituents of NER which is attached at Annexure- I for implementation of
recommendation of the committee on Grid Disturbance of Category V in NER on
25.07.14.
3. Implementation the recommendations of the Protection Audit
As per para no 27 of CERC order in Petition No. 220/MP/2012 on 21.02.14,the
deficiencies, if any, in Category-A (the deficiencies which can be corrected without
any procurement) shall be rectified by the concerned STU and CTU within 2 months
of issue of the order and compliance report in this regard shall be submitted to NERPC.
All deficiencies of Category-B (deficiencies involving procurement of equipment)
shall be rectified within 6 months of issue of the order. In this regard, reasons of nonavailability of fund or delay in procurement process shall not be accepted. The
procurement and implementation is to be completed by each STU using their own fund
which can be reimbursed through a common request of funding through PSDF
forwarded through NERPC as per procedure recently approved by Government of India.
Constituents of NER are requested to intimate the status of rectification of
protection deficiencies under Category A & Category B.
4. Furnishing list of Numerical Relays installed at bus bars and ends of transmission
line & transformers
As per section 43.4.a of Technical Standards for construction of Electrical Plants and
Electric Lines Regulation, 2010, numerical relays shall be provided for transmission
lines, transformers and bus bars.
Constituents are requested to furnish list of Numerical Relays installed at bus bars and
ends of transmission line & transformers and list of inbuilt features of these numerical
relays as per enclosed format in Annexure -II.
Constituents are also requested to furnish list of Disturbance Recorder, Event
Logger/Sequential Event Recorder, Fault Locator and Data Acquisition System
(DAS) installed/activated at ends of transmission line & transformers as per enclosed
format in Annexure -II.
.
7. The following numbers of Grid Disturbances(GD) occurred during the period w.e.f 01st
October, 2014 to 26th October, 2014 :Sl
No
Control Area
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Palatana
AGBPP
AGTPP
Ranganadi
Kopili
Khandong
Doyang
Loktak
Arunachal Pradesh
Assam
Manipur
Meghalaya
Mizoram
Nagaland
Tripura
Sl
No
1
2
3
4
5
Category of GD
GD 1
GD 2
GD 3
GD 4
GD 5
Total
This is for information to the members. Remedial actions are to taken by the
concerned power utilities of NER
8. Written reporting of events by constituents to NERLDC
As per section 5.9.6 of IEGC, written report of events by constituents is to be sent to
NERLDC with the following details:Time and Date of Event, Location, Plant and/or equipment directly involved,
Description and cause of event, Antecedent conditions of Load and Generation,
including frequency, voltage and the flows in the affected area at the time of tripping
including weather condition prior to the event, Duration of interruption and Demand
and/or generation (in MW and MWh) interrupted, All relevant system data
including copies of records of all recording instruments including Disturbance Recorder,
Event Logger, DAS etc, Sequence of tripping with time, Details of Relay Flags and
Remedial measures.
Events occurred during period w.e.f 22.09.14 to 26.10.14 attached. Constituents are
requested to submit the informations which were not furnished earlier as per attached
format for analysis of root cause of tripping.
9. Root cause analysis of Tripping of Multiple elements
i.
At 1508 Hrs on 07.10.14, 220 kV Sarusajai - Langpi I line (Sarusajai: DP, ZI, YB-E & Langpi: DP, ZI, Y-B-E) & 220 kV Sarusajai - Langpi II (Relay Flag: Not
furnish) lines tripped.
Due to tripping of these elements, there was loss of 100 MW generation of Langpi.
Grid Disturbance: GD I
Analysis of events :
It appears from the relay flags that fault was at 220 kV Sarusajai Langpi I line,
which were not cleared timely by Sarusajai. Due to delayed clearance of this fault,
fault was seen by 220 kV Sarusajai Langpi II line at Sarusajai & the line tripped.
These elements were radially connected.
For further analysis of these events, DR & EL output are required.
AEGCL may explain
ii.
At 1110 Hrs on 15.10.14, 220 kV Sarusajai - Langpi I line (Sarusajai: DP, ZI, BE & Langpi: Not furnish) & 220 kV Sarusajai - Langpi II Relay Flag: Not
furnish) lines tripped.
Due to tripping of these elements, there was loss of 100 MW generation of Leshka
& Khandong.
Grid Disturbance: GD I
Analysis of events :
It appears from the relay flags that fault was at 220 kV Sarusajai Langpi I line,
which were not cleared timely by Sarusajai. Due to delayed clearance of this fault,
fault was seen by 220 kV Sarusajai Langpi II line at Sarusajai & the line tripped.
These elements were radially connected.
For further analysis of these events, DR & EL output are required.
AEGCL may explain.
iii.
Analysis of events :
As 132 kV Balipara Depota line, 132 kV Balipara Gohpur line & 132 kV
Balipara Khupi line were connected radially, it was not understood why these
lines tripped simultaneously. For Root cause analysis, DR & EL output are
required.
POWERGRID, AEGCL may explain
iv.
v.
vi.
Analysis of events :
These elements were connected radially. It is not known whether any fault was
persisted in downstream element of MSPCL. Relay flag details at Imphal
(MSPCL) not furnished.
MSPCL may explain
vii. At 1451 Hrs on 13.10.14, 132 kV Imphal (PG) - Imphal (Manipur) I line
(Imphal(PG) : Dir EF & Imphal(MSPCL) : Not furnish) & 132 kV Imphal
(PG) - Imphal (Manipur) II line (Imphal(PG) : Dir EF & Imphal(MSPCL) : Not
furnish) tripped.
Due to tripping of these elements, power supply to Imphal area of Manipur
interrupted.
Grid Disturbance: GD I
Analysis of events :
These elements were connected radially. It is not known whether any fault was
persisted in downstream element of MSPCL. Relay flag details at Imphal
(MSPCL) not furnished.
MSPCL may explain
viii. At 1410 Hrs on 18.10.14, 132 kV Loktak Jiribam line (Loktak : DP, Z-I, RY-E
& Jiribam: DP, Z-I, RY-E) , 132 kV Dimapur Imphal line (Dimapur: DP, ZII, RY-E & Imphal: No tripping) tripped.
Due to tripping of these elements, power supply to major part of Manipur
interrupted and there was 50 MW generation of Loktak.
Grid Disturbance: GD I
Analysis of events :
It appears from the relay flags that fault was at 132 kV Loktak Jiribam line,
which were not cleared timely by Jiribam. Due to delayed clearance of this fault,
fault was seen by 132 kV Dimapur Imphal line at Dimapur & the line tripped.
For further analysis of these events, DR & EL output are required.
POWERGRID may explain
ix.
xi.