PROTECTION SUB- COMMITTEE MEETING HELDON 2. … for... · AGNEDA FOR THE 15th MEETING OF PROTECTION...

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SOUTHERN REGIONAL POWER COMMITTEE BANGALORE

AGNEDA FOR THE 15th MEETING OF PROTECTION SUB- COMMITTEE OF SRPC TO BE HELD ON 18.07.2012.

1. CONFIRMATION OF THE MINUTES OF THE 14th

PROTECTION SUB- COMMITTEE MEETING HELD ON

21st March 2012.

2. SYSTEM DISTURBANCES

The System Disturbances / Occurrences in the Southern Region

showing Details of Grid disturbances, Grid Incidences and the details of

Talcher Kolar HVDC pole tripping Incidences are given in Annexure- I as

given by SRLDC vide Lr. No SRLDC/SRC&S/Prot/2012 /4559 dt.

13.06.2012 (Annexure II).

3. Grid Disturbances in the Southern Region

3.1 Grid Disturbance on 3rd April 2012

(i) Time and date of event : 3rd April 2012 at 11.02 Hrs (ii) Location : North Karnataka

(iii) Plant and/or Equipment directly involved :

North coastal Karnataka and 400 kV Guttur SS, 400kV Kaiga SS,

400kV Narendra and Nagjheri, Kodasalli, Kadra, Kaiga, Narendra, Hubli,

Bidnal, Guttur and Ambewadi S/S become dead.

(iv) Description and cause of event

At 11:01 Hrs, due to a suspected momentary DC grounding of the

isolator NO/NC contact wires running from individual bay bus selection

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isolator to 400kv bus bar protection relay panel, Bus bar protection

relay operated at 400kV Guttur.

(v) 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

It is requested that the above data may be submitted on or

before 10.07.2012 by Email (KPTCL) .

(vi) Demand / Generation interrupted

Generation Loss- 2200 MW and Load Loss – 2000 MW

(vii) Duration of Interruption, All Relevant system data including copies of

records of all recording instruments including Disturbance Recorder,

Event Logger, DAS

(viii) Sequence of trippings with time.

(ix) Details of Relay Flags

(x) Remedial measures

It is requested that the above data (item vii to x) may be

submitted on or before 10.07.2012 by Email (KPTCL).

3.2 Grid Disturbance on 18th April 2012

(i) Time and date of event : 18th April 2012 at 09.23 Hrs (ii) Location : Neyveli ,Tamilnadu


Neyveli TPS-2 400 KV Sub station

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At 09:23:39 Hrs, Due to internal fault in the B-phase SF6 CT of

400 KV Neyveli-TPS- Puducherry line, SF6 pressure has come down

to zero and feeder got tripped. During the auto reclosing at 09:23:40

Hrs both the 400 KV buses got cleared on Bus bar protection.

Neyveli TPS 2 Stage II Units 4, 5, 6 & 7 went on house load and

400 KV Neyveli TPS 2 buses (Double Main one Transfer Bus scheme)

became dead.




It is requested that the above data may be submitted on or before

10.07.2012 by Email(NLC).


Generation Loss- 850 MW

(vii) Duration of interruption , All Relevant system data including copies of


Event Logger, DAS




It is requested that the above data (item vii to x) may be submitted

on or before 10.07.2012 by Email(NLC).

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3.3 Grid Disturbance on 27th April 2012 (i) Time and date of event : 27th April 2012 at 17.45 Hrs (ii) Location : Guttur, Karnataka


400 KV Guttur Substation


A Bus fault occurred at 400kV Guttur SS due to flashover of B-

phase Lightening Arrester of 400kV Guttur-Hiriyur-Line 2. Bus bar

protection operated and all 400 KV feeders got tripped along with

400/220 KV ICTs.





10.07.2012 by Email(KPTCL) .


Generation Loss- 415 MW



Event Logger, DAS





on or before 10.07.2012 by Email(KPTCL).

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4. Grid Incidences in the Southern Region

4.1) Grid Incidence in VTS Generating station on 18.05.2012

(i) Time and date of event : 18th May 2012 at 00.25 Hrs (ii) Location : VTS Generating station


VTS Generating station


220kV Bus-II at VTS Generating station got cleared due to Bus fault.

The fault was created due to CT blast on 220kV VTS- Tadikonda-II

feeder. Out of 6 units three units, Unit # 2, 3 & 6, got tripped





10.07.2012 by Email (APTRANSCO) .


Generation Loss- 600 MW.



Event Logger, DAS





on or before 10.07.2012 by Email(APTRANSCO).

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4.2) Talcher Kolar Pole Trippings

S No Details of Event Date & Time Reason Kolar SPS Talcher

SPS

Remarks

1

Talcher-Kolar Pole-1 tripped and Pole-2 came on Metallic Return mode. Power Flow came down from 2460MW to 387 MW. Frequency came down from 49.90 Hz to 49.18Hz.

29.02.2012 @03:10Hrs

Due to failure of 24 Volt DC power supply to pole control system due to short circuit in ATR OE4 card.

Inter trip signal-1

generated

Unit#5 and

Unit#6 tripped

The Grid Incidence

was Discussed in the 14 the PCC Meeting.

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Talcher-Kolar Pole-1&2 tripped. Power Flow came down from 1970 MW to 0 MW. Frequency came down from 49.79 Hz to 48.88Hz.

22.04.2012 @14:32Hrs

Pole -1 & 2 tripped due to Commutation failure, which was happened due to R-phase CT blast of 220kV Somanahalli- HSR layout at Somanahalli end. 400/220kV Somanahalli ICT-1&2 Tripped on backup over current protection.

SPS not operated

Unit # 6 tripped

and Generati

on of Unit#4&5 back

down by 150 MW

each.

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Talcher-Kolar Pole-1 tripped and Pole-2 came on Ground Return mode. Power Flow came down from 1970MW to 147MW. Frequency came down from 49.79 Hz to 49.16Hz.

01.05.2012 @17:48Hrs

Due to HVDC line fault at Location no 56, 18.47 km from Talcher end.

Inter trip signal-1&2 generated

Unit # 6 tripped

and Generati

on of Unit#4&5 back

down by 150 MW

each

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19.05.2012 @16:14Hrs



Unit # 6 tripped

and Generati

on of Unit#5 back

down by 150 MW.

It is requested that the Details of Event Report as envisaged in the

IEGC 5.9.6 (c) for the above incidents may be sent latest by

10.07.2012(SRTS II,PGCIL).

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5. Minor Trippings

The Minor tripping in the Southern Region are given in Annexure III

as submitted by SRLDC vide Lr No SRLDC/SRC&S/Prot/2012 /4559

dt. 13.06.2012 .

6. Requirement of SPS for 400 KV Nellore-Almatti DC line

contingency:

SRLDC Vide Lr No Lr No SRLDC/SRC&S/Prot/2012 /4559 dt.

13.06.2012 (item No 5) proposed for a System Protection Scheme for 400

KV Nellore-Almatti DC Line contingency.

With the commissioning of Simhapuri (300 MW) and Meenakshi

(300 MW) 400 KV Nellore-Almatty DC line will get severely loaded. The

strengthening of this corridor would be achieved with the Commissioning

of the Nellore-Thiruvalam line which is expected by the year 2014. SRLDC

is proposing an SPS to back down generation at Simhapuri & Meenakshi

to alleviate the post contingency flows on N-1 condition of this line.

Members may discuss.

7. SPS for 220kV Chittur- Tiruvalum and 220kV Sullurpet-

Gummidipoondi lines:

SRLDC Vide Lr No Lr No SRLDC/SRC&S/Prot/2012 /4559 dt.

13.06.2012 (item No 15) proposed for a System Protection Scheme for

220kV Chittur-Tiruvalum and 220 KV Sullurpet-Gummidipoondi lines.

Presently, 220 KV Chittur-Tiruvalum line O/C setting at Chittur end

is 420 A (160 MW) and 220 KV Sullurpet-Gummidipoondi line O/C setting

at Sullurpet end is 260 A (100 MW). The constraint is due to the loading

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concern on the upstream lines. Considering this fact it is prudent to design

an SPS to trip 220 KV Chittur- Tiruvalum and 220 KV Sullurpet-

Gummidipoondi lines based on the loading of the critical upstream lines

instead of over current protection and Line will be protected by distance

protection.


8. 400 kV Hiriyur-Nelamangala D/C Contingency SPS

Proposal for a SPS in 400 KV Hiriyur –Nelamangala Line was

discussed in the PCC and OCC meetings. In view of proposed

commissioning of Bellary TPS Unit-II a SPS during tripping of one

circuit of 400 kV Hiriyur-Nelamangala line when flow of each line was

more than 560 MW was deliberated in the meetings.

It was informed that 400kV Hiriyur-Nelamangala SPS was

implemented partially (tripping of Jindal units were wired, BTPS final

link for tripping yet to be extended). It was noted in the 72nd meeting of

OCC that the SPS scheme was under active implementation by

KPTCL. It was informed that the remaining pending works would be

completed in about one monts time.

The status of the SPS may be intimated to the forum.

9. SPS at Hosur S/S

The SPS at Hosur proposal was discussed in the PCC & OCC

meetings. In the meetings PGCIL stressed for the immediate need for

SPS at Hosur S/S till ICT-III gets commissioned. This was in order to

avoid overloading of the surviving ICT in case of tripping of one ICT. After

deliberations, Protection Committee had recommended that

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TANTRANSCO to identify the loads which could be tripped in contingency

to avoid overloading of ICT at Hosur.

v The scheme was discussed in the 19th SRPC meeting held on 1st June

2012. The Committee had approved the SPS for 400 kV Hosur ICT as

proposed. It was also seen that the SPS scheme would be

implemented without affecting the loads of Karnataka and Tamil Nadu.

v SRTS II,PGCIL vide Lr No SR II/O&M/2012-13/F-42.0 dt 07.06.2012

informed that the controlled load shedding of 315 MVA ICTs at

400/220 KV Hosur S/s to mitigate the overloading of one ICT in case of

tripping of other has been implemented w.e.f 07.06.2012.

10. Status of provision of SPS Trip Signal 3 at Kolar

The proposal for Generation of third protection signal from Kolar in view

of higher power transfer (2000 to 2500 MW) was approved in 13th

SRPC meeting . In 14th PCC meeting SRTSII, PGCIL informed that

inter trip signal-3 would be ready by May-2012.

The Extended mode of operation of Talcher-Kolar HVDC link would

continue throughout the year as decided in SRPC meeting held on 1st

June 2012. The Trip Signal 3 to cover loss of 2500 MW is required to

be in place at the earliest and it would also be ensured that the other 2

Trip signals are generated and acted upon.

The status of provision of SPS trip signal 3 may be informed to the

forum.

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11. Modification of SPS Trip Signal at Kolar

SRTS II, PGCIL vide Email dt 07.06.2012 informed that the

modifications as suggested in the special meeting of PCC have been

implemented on 30.05.2012. PGCIL also informed that the revised

logics were uploaded in the PLC and tested locally and found to be

working. The revised logic is enclosed as follows.

Trip generation LOGIC

Condition 1:

((500MW<Power loss :S1000MW) & Pole Block) OR (l400MW< Power flow

:S1900MW) & Pole Block) OR (under one pole s/d (500MW<Power flow <1000MW))

other Pole Blocks= TRIP I

Condition 2: (650MW<Power flow :S1150MW) & Line fault & Pole Block = TRIP I

Condition 3: ((Power loss >1000MW) & Pole Block OR (Power flow >1900MW) &

Pole Block) OR (under one pole s/d (Power flow> 1000MW)) other Pole Blocks =

TRIP II

Condition 4: (Power flow> 1150MW) & Line fault & Pole Block = TRIP II

*Power loss = DC power at Kolar at (t-2sec) - DC power at Kolar at (t) where t is the

time instant when Block signal is available.

Power flow = DC power at Kolar at (t-2sec).

12. SPS for Kudankulam

The following had been noted up to the 14th PCC meeting

• It was informed that all the substation works has been completed and the

substation was energized.

• PGCIL/SRTS II informed the forum that the SPS would be ready by April

2012.

• The PCC forum requested SRTS II / PGCIL to commission the SPS within

the agreed date.

The status of implementation of SPS may be informed to the forum.

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13. SPS at Varahi

The PCC forum envisaged a SPS at Varahi in the earlier PCC

meetings. Approximately 1050 MW ( more than 450 MW at Varahi and

600 MW of UPCL) had to be evacuated through 220 kV Varahi –

Shimoga D/C line and 220 kV Kemar – Shimoga S/C. It was informed

that 220 kV Varahi – Shimoga D/C line severely loaded with no N-1

reliability.

Up to 14th PCC the following pointes were minuted:

• The PCC forum proposed to have an SPS scheme at Varahi, which

can trip the generation in the event of 220 kV Varahi – Shimoga line

outage.

• If any one of the three lines i.e. Varahi- Shimoga Line 1&2 and Kemar

- Shimoga Line trips Varahi generation has to be brought to 100 MW

(at present two units has to be tripped) to avoid over loading of other

lines in the corridor.

• When the Fourth unit of Varahi comes into operation (i.e. all the four

units are generating to its full capacity ) and if any one of the above

stated three line trips , three units of Varahi should be tripped to

maintain the generating capacity around 100 MW.

• KPCL to identify the tripping sequence of units considering supply to

the auxiliaries are not affected by tripping of units.

• KPCL will be the implementing agency for the SPS scheme.

• The Scheme will be reviewed when Nandikur- Shantigrama 400 KV

(Quad moose Conductor) line commissioned by KPTCL.

• KPTCL informed the forum that KPTCL part of works in the SPS were

completed and they were waiting for KPCL clearance.

The progress of work regarding provision of SPS may be intimated to the

forum.

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14. SPS for S1-S2 bid area:

The PCC forum had suggested for an SPS to shed loads of 300 MW at

Salem to limit post contingency stress in S1-S2 corridor whenever one

of 400 KV Hosur-Salem and 400 KV Somanahalli-Salem line trips.

Up to 14th PCC the following the following were noted: • The SPS proposal was discussed in various SRPC forum meetings and

TANTRANSCO had agreed to implement the same.

• TANTRANSCO had identified the loads to be shed in the SPS scheme

and also given a cost estimate of Rs. 25 lakhs to implement the

scheme.

• Loads were identified by TANTRANSCO and the wiring and associated

works will be taken up by them.

• The higher loading will be utilized to operate Kadamparai Power House

in pump mode operation.

• SRLDC informed that the app cost of PLC and wiring would be around

` 50 lakhs apart from ` 25 lakhs for TANTRANSCO portion.

• The forum is on the opinion that the feeders should be tripped

automatically and not through manual intervention.

• CE, TANTRANSCO informed that loads were identified and the SPS

works will be started at the earliest.

• The issue was discussed in the 70th- 72nd OCC and the OCC forum

also requested TANTRANSCO to implement the SPS at the earliest.


15. SPS at Muddanur:

The PCC forum proposed a SPS at Muddanur in the earlier

PCC meetings. The Muddanur generation (about 800 MW) has to be

evacuated through four 220 kV lines, 220 kV D/C Chinnakampally and

220 kV D/C Ananthapur and radial loadings of 200 kV Pulivendula (120

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MW) and 220 kV Yerraguntla (80 MW). In case of tripping of one of

the lines of 220 kV Chinnakampally other line get over loaded and may

lead to cascade tripping.

Up to 14th PCC meeting the following points were minuted:

• The SPS scheme was proposed to back down generation in case of

one or both 220 kV Muddanur-Chinnakampally lines trips.

• It was also informed that the SPS would be reviewed keeping in views

of commissioning of Lines / Generating units at Rayal Seema.

• APTRANSCO informed the forum that by June 2012 the SPS would be

operational.

• APTRANSCO also informed that unit No 5 was identified to back down

the generation (as a part of SPS).


16. SPS on 400 kV Vijayawada-Nellore line:

The PCC forum proposed a SPS to back down generation at

Vemagiri complex in case of tripping of one of the 400 kV Vijayawada-

Nellore line when each line carrying 550 MW . The issue was

discussed in various SRPC forum meetings and SRLDC had also

provided additional study results.

v The PCC forum requested APTRANSCO in co-ordination with the IPPs

/ SRTS I (PGCIL) would implement the SPS within the agreed time.

v The issue was discussed in the 19th SRPC meeting held on 1st June

2012. After discussions, it had been decided that a Sub Group

consisting of members from constituents would be formed to deliberate

on the scheme and suggest any review, in the changed scenario.

v The deliberations of this Sub Group would be put up to Special TCC for

consideration.

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17. Operation of various SPS Scheme in the Southern

Region

Up to 14th PCC the following were minuted:

The PCC forum opined that the operation of Various SPS schemes in the

Southern Region may be brought to the notice of the forum during the PCC

meeting. The forum proposed that the operation, non operation and mal

operation of the SPS schemes would be reported to the forum and discussed

in the forth coming PCC meeting.

v The forum requested all the constituents to send the particulars of

operation, non operation and mal operation of the SPS schemes to the

SRPC Secretariat at the earliest.

All the constituents are requested to send the particulars of operation, non

operation and mal operation of SPS in the their system latest by 10.07.2012

through Email .

v In the sub group meeting of PCC held on 30th April at Kaiga it was

proposed to review the existing SPS at Nagjheri to take care of line

loadings on Bidnal-Harthi and Hubli-Sirsi lines (action KPTCL) .The

copy of the meeting is enclosed as Annexure IV.

18. Uniformity in Protection Philosophy in SR

(i) TANTANSCO vide Lr No CE/P&C/SE/D/EPC2/AEE3/f SRPC/Dt

08.06.12 given the following agenda .

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(ii) KSEB vide Lr No.CESO/EELD1/AE2GS/ PC/ 2012-13 dt nil sent the

following agenda In the 12th meeting of the Special Protection

committee, it was decided to adopt a zone II timing of 350 msec for

having a uniform protection philosophy in the Southern region. Based on

that, the Zone II timing for majority of 220kV feeders in our region have

been changed to 350msec. But it was noticed that the setting of the

feeders at Power grid end was non-uniform and because of this grading is

not achieved. The current settings of the PGCIL feeders are listed below.

Name of feeder current Zone#2 setting at PGCIL end 1. 220kV PGCIL #1 at PothencodeS/s 450msec 2. 220kV PGCIL #2 at PothencodeS/s 450msec 3. Edamon- Thirunelveli#1 at EdamonS/s 300msec 4. Edamon- Thirunelveli#2 at Edamon S/s 300msec 5. Kundara- Kayamkulam at Kayamkulam GIS S/s 500msec 6. Edappon- Kayamkulam at Kayamkulam GIS 500msec Members may discuss .

19. Provision of Single Phase Auto-Reclosing, Carrier Aided

tripping and Bus Bar Protection Scheme on 220 KV and above

lines in SR.

In the earlier PCC meetings, it was agreed to have single phase auto-

Reclosing scheme on all lines emanating from all major generating stations

including nuclear stations and on all 220 kV and above rated lines. The PCC

forum recommended that all the constituents to have carrier aided tripping for

all the 220 KV and above rated lines. The forum also recommended that all

the constituents to have an independent Bus Bar protection scheme to protect

their transmission system elements.

It was also decided to create a data base of lines provided with Single

phase/Three Phase Auto Reclosing facility, Lines provided with carrier aided

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tripping and Sub stations provided with Bus bar Protection Scheme. All the

constituents had been requested to submit the requested data for base

creation

Up to 14th PCC meeting the following points were minuted:

• As on date the status of data submitted by the constituents is as

follows.

S.No Constituent Carrier Aided Tripping Status

Single Phase Auto reclosing status

Bus Bar Protection status

1 APTRANSCO Data Submitted

Data Submitted

Data * Submitted

2 KSEB Data Submitted

Data submitted

Data* Submitted

3 KPTCL Data Submitted

Data submitted

Data* Submitted

4 TANTRANSCO Data Submitted

Data submitted

Data* submitted

5 SRTS I,PGCIL Data Not submitted

Data Not submitted

Data Not* submitted

6 SRTS II,PGCIL Data Submitted

Data submitted

Data Submitted

6 NTPC Data Not ^ submitted

Data Not ^ submitted

Data Not * submitted

7 NLC Data Submitted

Data Submitted

Data Submitted

8 MAPS,NPCIL Data Not ^ submitted



9 KAIGA,NPCIL Data Not ^ submitted



10 Puducherry Data Submitted

Data submitted

Data submitted

* Requested to send the updated List of Substations provided

with Bus Bar Protection in as per the Annexure V.

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^ Requested to send the updated List of Lines provided with

Carrier Aided Tripping /Single Phase Auto Reclosing scheme

as per the Annexure VI .

It is requested that all the constituents may send the updated status

of implementation of provision of Carrier Aided Protection facility, Single

Phase Auto reclose facility and provision of Bus Bar Protection facility in

the 220 KV and above network in Electronic format latest by 10.07.2012

to the following Email IDs.

• 1. [email protected]



20. Agenda from SRTS II,PGCIL

SRTS II,PGCIL vide E Mail sent the following Agenda

i. Commissioning of carrier aided protection scheme for all 220 kV lines

ii. Overloading of ICTs at Thirunelveli & Madurai- Requirement of SPS

scheme: The Thirunelveli & Madurai ICTs are operating at near to full

load and operating at overloads intermittently. The requirement of SPS

may please be discussed in the meeting.

iii. Submission of tripping reports to SRLDC/SRPC by all utilities.


21. Islanding scheme for Jindal, BTPS.

An islanding scheme covering Munirabad, Kustagi Sindhanur

Loads and JSW Generators was proposed in the earlier PCC meetings.

It was brought to notice of the forum that M/s. Jindal has an islanding

scheme in operation where 1 x 100 MW and 1 x 133 MW units island

with 180 MW load of its steel plant. As JSW has a load of 500 MW,

M/s. Jindal was asked to explore possibility of a second island. M/s.

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KPTCL / KPCL was also requested to formulate an island for BTPS

with radial loads at Munirabad, Kustagi and Sindhanur.

Up to 14th PCC meeting the following points were minuted: • It was informed that the 400 kV double circuit line between BTPS and

Hiriyur and second unit of 500 MW at BTPS are expected to be

commissioned in shortly.

• KPTCL submitted the Islanding scheme for management approval by

keeping 1 unit of 300 MW at JSW.

• The following Loads were identified by KPTCL for the proposed

islanding scheme. Kustagi :107 MW, Sindhanur:55 MW, Munirabad:49

MW,Alipur:80 MW,Total:291 MW.

The status of provision of islanding scheme may be intimated to the

forum.

22. Islanding Scheme for Kaiga

The provision of Islanding scheme for Kaiga Generators was discussed

in the earlier PCC meetings . Kaiga, NPCIL was requested to formulate

the Kaiga islanding scheme with adjoining loads in consultation with

SRLDC, KPTCL &PGCIL.

• Islanding scheme for Kaiga was discussed in detail in the 1st meeting of

monitoring committee held on 06.06.2012 and it was proposed to have

two islands called “Island12” and “Island34”. Details of scheme are

attached as Annexure VII .

The status of the formulation of Islanding Scheme may be intimated to

the PCC forum.

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23. Non Submission of complete tripping Report by the

constituents.

SRLDC vide Lr No SRLDC/SRC&S/Prot/2012 /4559 dt. 13.06.2012

(item no 13) informed that though the constituents have started giving

tripping reports for the trippings in their system most of the constituents

are not submitting the DR/EL printouts.

Members may discuss the issue.

24. Review of Installation of Frequency Trend Relays (df/dt)

and revision of df/dt settings in SR

The df/dt protection scheme is in operation in the Southern

Regional grid with the following two settings. The details of the load

relief obtained through this scheme is given in the table furnished

below:

- 49.5Hz with rate of fall of 0.3Hz / sec. for alarm;

&

- 49.3Hz with rate of fall of 0.3Hz / sec. instantaneous - for trip.

df/dt Relays installed in Southern Region:

S.NO Constituent System

df/dt relay Setting Expected load relief (MW)

1 APTRANSCO 49.3 Hz, 0.3 Hz / Sec, Instantaneous

1767

2 KPTCL -do- (485 – 1036) 3 TANTRANSCO -do- 559 4 KSEB -do- (121 – 175) Total load relief in

SR (2909 – 3530)

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• The PCC forum proposed a new df/dt settings for the SR system.

• Present df/dt Settings in SR:

ALARM: Frequency <= 49.5 Hz and 0.3 Hz/sec fall of frequency (df/dt)

Trip: Frequency <=49.3 Hz and 0.3 Hz/sec fall of frequency (df/dt)

Then

Load relief expected: 3530 MW in Peak condition

2909 MW in off Peak condition

• Proposed df/dt Settings in SR in addition to the existing setting:

ALARM: Frequency <= 49.8 Hz and 0.2 Hz/sec fall of frequency (df/dt)

Trip: Frequency <=49.5 Hz and 0.2 Hz/sec fall of frequency (df/dt)

Then

Load relief expected: 2000 MW in Peak condition.

• The settings would be reviewed when the system requires change in

the revised settings.

• The issue was also discussed in the 70th – 72nd OCC and the

constituents were briefed about the revision in the df/dt settings.

Progress of implementation of the scheme may be intimated to the forum.

25. The issue of sending completed Dynamic Study data

In the 13th PCC the forum decided to collect the Dynamic study data

from the utilities to study the Southern Region system. The dynamic

study format was circulated to the constituents to send the Generator,

Excitation system, Governor, HVDC parameters .TNEB, NLC, NTPC,

Kayankulam and KSEB had submitted the filled format.

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• The forum opined that the dynamic study details of the IPPs also would

be necessary to conduct the study on whole SR system.

• All the SLDCs were requested to direct the embedded IPPs connected

at 220 KV and above voltage level to send the completed dynamic

study format (Annexure VIII) to the SRPC, Secretariat.

• It is requested that the dynamic study data in the stipulated format may

be sent to us latest by 25.04.2012 by Email to the following Email IDs.

1. [email protected]

2 [email protected]

3. [email protected]

NTPC (Ramagundam), KPCL, MAPS &KGS (NPCIL) were requested

to send the dynamic study data (Annexure VIII) latest by 10.07.2012.

26. Pilot PMU Project in the Southern Region.

The pilot PMU project was approved in the 14th SRPC meeting

held at Kochi on 27th August 2010. SRLDC proposed for 6 numbers of

Phasor Measurement Units for the Southern Region at an estimated

expenditure of Rs.4.0 Crores.


• SRLDC informed the forum that SRLDC and KALKITECH had installed

three Mini Pilot PMUs as a part of SRLDC WAMS Demo project.

• The mini Pilot PMUs were installed in 3 Locations (Hyderabad, Salem &

Somanahally). The locations were selected based on locations where

the power system and communication constraints persists.

• The mini Pilot PMUs were aimed to implement WAMs monitoring

system and to understand communication and system architecture

requirements.

• GM, SRLDC informed that 4 organizations had submitted their bids for

installation of PMU and technical evaluation were going on.

• It was noted that the PMUs would be installed within 3 to 4 months time.

The status of implementation of PMUs may be informed to the forum.

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27. Expected UFRs load relief quantum:

The Quantum of additional load relief to be provided by the constituents

for the year 2012-13 as calculated by SRPC is given below .

(Figures in MW) Constituents ? AP KAR KER TN PUDU SR Stage - I @ 48.8 Hz 25% 2478 866 534 240 842 18 2500

Stage - II @ 48.5 Hz 35% 3469 1206 703 127 1071 29 3136

Stage - III @48.2 Hz 40% 3964 1373 901 457 1207 34 3972

Total (implemented) ? 3445 2138 824 3120 81 9608

Additional Requirement ? 85 213 30 -31 6 303

• The constituents were requested to report the UFR trippings to SRPC

at the earliest.

The status of provision of designated relief may be intimated to the

PCC forum at the earliest.

28. Emergency Load Disconnection Scheme during

sustained over drawl at Low Frequency.

During the previous PCC meetings, SRPC had approved the

implementation of ALDS to trip the loads of the constituents which were

over drawing.

• It was noted that SRPC in its 14th meeting held on 27th August 2010

had agreed to implement Automatic Load Disconnection Scheme for

overdrawing constituents with the following relief:

23

Sl.No. Constituents Load Relief 1 APTRANSCO 450 MW 2 KPTCL 350 MW 3 KSEB 125 MW 4 TNEB 650 MW 5 Puducherry 25 MW

• KPTCL had earlier informed that 350 MW of load relief through remote

tripping of load under crisis period has been identified. The same is

under testing and final implementation stage and would be

implemented shortly.

• It was noted that Puducherry had provided remote tripping facilities in

the identified feeders in order to provide emergency disconnection.

The is for the information of the PCC forum.

29. Providing synchronizing facility at Key Stations for black

start restoration:

The issue of providing synchronizing facility at Key stations for

black start restoration was highlighted in the various SRPC forum

meetings.

The current status of synchronizing equipment installation at key

stations is as follows:

S.No Sync. facility requirement at station

Status

1 Hubli To be provided during R & M works. However Bidnal station is having synchronous facility. Nagjhari can be synchronized at Bidnal and then supply can be extended to Hubli as a temporary arrangement.

2 Mahlingapura Will be commissioned in 3 months

3 Kayathar 110 kV Action being taken

4 Kadra, Kodasahalli Yet to be provided

24

• All the Generators would have synchronization facility.

• The identified station would be provided with Synchronizing facility at

the earliest.

The status of provision of Synchronizing facility may be updated.

30. Protection aspects of Wind Turbines:

The PCC forum had emphasized the need to examine and optimize the

protection practices adopted for Wind Turbines as penetration levels

are increasing.

SRLDC vide Lr No SRLDC/SRC&S/Prot/2012 /4559 dt. 13.06.2012

(item no 14) give the following agenda.

On 03.06.2012 at 10:48Hrs one of the 110 KV wind pooling

Station, 110 KV O-Tulukapatti station went dead due to CT Blast in

110kV Kayathar – O- Tulukapatti Feeder Causing outage of about

500MW Wind Generation. SR Frequency Dipped from about 49.60Hz

to 49.00Hz.

There is a need to examine and optimize the protection practices

adopted for Wind Turbines as well as protection at Wind Pooling

stations as the penetration levels are increasing.

Members may discuss the issue.

31. Voltage Control Relays as per IEGC .

As per 5.2.(t) of System Security Aspect of Operating Code (Part -5)

of IEGC, voltage control relays should be provided. The IEGC “ The Users,

CTU and STUs shall provide adequate voltage control measures through

voltage relays as finalized by RPC to prevent voltage collapse ,and shall

ensure its effective application to prevent voltage collapse/cascade

tripping. Voltage Relays should be provided as per IEGC Guidelines” .

25

• The PCC forum recommended for feasibility study for provision of Voltage

control relays in the following nodes i.e. at Somanahalli, Sriperumbudur,

Kalavindapattu, Almatti, Mysore etc.

• In principle the forum had agreed to install the Voltage control Relays in the

nodes after resorting to all measures of MVAR control and at lower settings

so that phenomenon like load encroachment does not take place.

The status of provision of under voltage relays as mandated in IEGC

Regulations to control low voltages at the following 400 kV nodes:

Sriperumbudur, Almathy, Chittoor, Nellore, Mysore, Somanahalli,

Kalavindapattu, Trichur & Hosur may be intimated to the forum.

32. Review of Deliberations of 1st Monitoring Committee meeting and

other meetings of protection subcommittee.

Members may please give updates with regard to the items discussed in the

1st Monitoring committee meeting and the other meetings of protection

subcommittee held during 14th PCC and 15th PCC.

(i) Spl meeting of PCC held on 19.04.2012- Annexure IX

(ii) Spl meeting of PCC held on 30.04.2012- Annexure IV,X

(iii) Spl meeting of PCC held on 14.05.2012- Annexure XI

(iv) 1st Monitoring Committee of PCC held on 06.06.2012- Annexure XII

33. Date & venue of the next meeting.

The next PCC meeting will be held in the month of October 2012.The exact

date and venue shall be communicated in due course.

ANNEXURE I (Page 1 of 2)

1.Details of Grid Disturbances:

S No

Date & Time of Occurrence

Type

Load loss or

Generation loss

Area(s) affected Reason

1 3rd April 2012 11:02 Hrs

GD1

Gen.Loss-2200MW Load Loss - 2000MW

North coastal Karntaka and 400kV Guttur SS, 400kV Kaiga SS, 400kV Narendra and Nagjheri, Kodasalli, Kadra, Kaiga, Narendra, Hubli, Bidnal, Guttur and Ambewadi become dead.

At 11:01 Hrs,due to a suspected momentary DC grounding of the isolator NO/NC contact wires running from individual bay bus selection isolator to 400kv bus bar protection relay panel, Bus bar protection relay operated at 400kV Guttur.

2 18th April 2012 09:23 Hrs

GD1 Gen.Loss-850MW

NeyveliTPS-2 400kV Sub station

At 09:23:39 Hrs, Due to internal fault in the B-phase SF6 CT of 400kV Neyveli-TPS- Pondy line, SF6 pressure has come down to zero and feeder got tripped. During the auto reclosing at 09:23:40 Hrs both the 400kV buses got cleared on Bus bar protection. Neyveli TPS 2 Stage II Units 4, 5, 6 & 7 went on house load and 400kV Neyveli TPS 2 buses (Double Main one Transfer Bus scheme) became dead.

3 27th April 2012 17:45 Hrs

GD1 Gen.Loss- 415MW

400kV Guttur Substation

A Bus fault occurred at 400kV Guttur SS due to flashover of B-phase Lightening Arrester of 400kV Guttur-Hiriyur-2. Bus bar protection operated and all 400kV feeders got tripped along with 400/220kV ICTs.

2.Details of Grid incidents

1 220kV Bus-II cleared due to bus bar protection operation

18.05.2012 @00:25Hrs

220kV Bus-II at VTS Generating station got cleared due to Bus fault. The fault was created due to CT blast on 220kV VTS-Tadikonda-II feeder. Out of 6 units three units, Unit#2, 3&6, got tripped and there was a generation loss of about 600 MW.

- -

ANNEXURE I (Page 2 of 2)

3) Talcher Kolar Pole Trippings

S No Details of Event Date & Time Reason Kolar SPS Talcher

SPS

Remarks

1

Talcher-Kolar Pole-1 tripped and Pole-2 came on Metallic Return mode. Power Flow came down from 2460MW to 387 MW. Frequency came down from 49.90 Hz to 49.18Hz.

29.02.2012 @03:10Hrs

Due to failure of 24 Volt DC power supply to pole control system due to short circuit in ATR OE4 card.

Inter trip signal-1

generated

Unit#5 and

Unit#6 tripped

.

2

Talcher-Kolar Pole-1&2 tripped. Power Flow came down from 1970 MW to 0 MW. Frequency came down from 49.79 Hz to 48.88Hz.

22.04.2012 @14:32Hrs

Pole -1 & 2 tripped due to Commutation failure, which was happened due to R-phase CT blast of 220kV Somanahalli- HSR layout at Somanahalli end. 400/220kV Somanahalli ICT-1&2 Tripped on backup over current protection.

SPS not operated

Unit # 6 tripped

and Generati

on of Unit#4&5 back

down by 150 MW

each.

3


01.05.2012 @17:48Hrs



Unit # 6 tripped

and Generati

on of Unit#4&5 back

down by 150 MW

each

4


19.05.2012 @16:14Hrs



Unit # 6 tripped

and Generati

on of Unit#5 back

down by 150 MW.

PROTECTION SUB- COMMITTEE MEETING HELDON 2. … for... · AGNEDA FOR THE 15th MEETING OF PROTECTION...

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