SOUTHERN REGIONAL POWER COMMITTEE Minutes of the Protection Coordination Sub-Committee€¦ · ·...

SOUTHERN REGIONAL POWER COMMITTEE BANGALORE

Minutes of the 31st Meeting of

Protection Coordination Sub-Committee of SRPC held on 29.04.2014

1 Introduction

The 31st Meeting of Protection Coordination Sub-Committee (PCSC) was held on

29th April 2014 in the Conference Hall of Southern Regional Power Committee,

Bangalore. The list of participants of the PCSC meeting is enclosed as Annexure -

I.

Shri S. R. Bhat, Member Secretary i/c, SRPC welcomed the Members and the

Participants to the 31st Meeting of the Protection Coordination Sub-Committee.

Member Secretary i/c stated that as the Members were aware, Hon'ble CERC had

issued directions regarding implementation of protection audit in two phases. He

also informed the forum that only KPTCL and KPCL had submitted the status of

implementation of protection audit recommendations as on date . He requested other

constituents to similarly submit the details latest by 1st May in respect of Phase-I

and by 1st September 2014 for Phase-II so that the same could be forwarded to

Hon'ble CERC.

MS i/c , SRPC informed the forum that NLDC has proposed review of SPS for 765

KV Lines. The same could be deliberated and finalized in the PCSC. The intent was

on reduction in the number of SPS operations, on which the states ha d given

considerable feedback. He thanked NPCIL for conveying their response on various

issues concerning KKNPP.

MS i/c , SRPC expressed concern over the number of tripping events that had

occurred in Vallur (NTECL) & NCTPS (TANGEDCO) areas on account of fog/

pollution etc. He urged NTECL, PGCIL and TANGEDCO to address the issue

effectively and evolve a long term solution to the problem. It was noted that the line

trippings had created anxious moments for the utilities on account of Lok Sabha

Election-2014 for which uninterrupted power supply has to be ensured on the day of

polling etc.

Minutes of the 31st Protection Coordination Sub Committee Meeting held on 29.04.2014 Page 2

MS i/c, SRPC also informed the forum that the "Report of the Task Force on Power

System Analysis under contingencies" had been posted in the CEA Website. He

requested Members to kindly peruse the Report in the interest of protection system

of the southern Region. He informed that all utilities should follow the guide lines

and get their protection system audited from time to time as per the recommended

methodology for relay settings. A data base of the settings of various relays also

needs to be created, kept updated and verified during the relay audit. He also

informed that Islanding schemes had (chapter-5) also been deliberated in the Report

and to be taken up for discussions.

2 Confirmation of the Minutes of the 30th PCSC Meeting held on 20th March 2014

The Minutes of the 30th PCSC meeting were confirmed since no comments were

received from the constituents.

3 Grid Disturbances in the Southern Region

3.1 Grid Disturbance at 400kV Gooty substation on 03.04.2014 (i) Date and Time of event 03.04.2014 at 16.09 Hrs (ii) Location Gooty, AP

(iii) Plant and/or Equipment directly involved

400kV Gooty Substation, PGCIL

(iv) Reported Disturbance / Fault

Failure of B-phase current transformer in 400 kV Gooty-Raichur led to tripping of all connected lines and ICT’s at Gooty Substation.

(v) Load Loss 228 MW (vi) Duration of interruption 35 Minutes to 7 Hours 43 Minutes (vii) Category GD 1

Deliberations:

• It was noted that the Raichur-Gooty Line I is connected to Bus-2 and Raichur-Gooty Line II is connected to Bus-1; these two lines were adjacent to each other.

• B-Phase current transformer of 400kV Gooty-Raichur line -1 got failed which resulted in a bus fault in 400kV Bus -2 at Gooty substation and led to disconnection of lines connected to that bus; the blasting of CT was followed by release of thick black cloud in the vicinity.

• Bus-1 fault: the black cloud engulfed the bus-1 area also and created a flash over on B-phase interrupter column of CB of Raichur -II resulting in a bus-fault that disconnected lines connected to Bus-1.


• Nelamangala & Bangalore lines did not trip at remote end and the tie was not opened at Gooty; also Nellore PS – line1 & line 2 did not trip at remote end.

• PGCIL opined that "D" scheme of bays in one and half breaker scheme has closer physical proximity, it would be reviewed to have "I" scheme which is better to prevent such faults.

• SRLDC observed that the DR time was not synchronized with the GPS.

3.2 Grid Disturbance at 220 KV Chinnakampally (Kadapa) Substation on 06.04.2014

(i) Date and Time of event 06.04.2014 at 01:55 Hrs (ii) Location Chinnakampally ,AP


220 kV Chinna kampally (Kadapa) Substation, APTRANSCO


ICT-1 & 2 got tripped on operation of high set of directional Over current protection of LV side of ICT’s. It was reported that there was a CT failure in 220kV RTPP feeder at 220kV switchyard of Kadapa SS.

(v) Generation Loss 210 MW (RTPP Unit 3) (vi) Duration of interruption 58 Minutes to 16 Hour 55 Minutes

(vii) Category GD 1

Deliberations:

• It was noted that CT failure on Kadapa -Rayalaseema TPP 220 kV line at APTRANSCO had resulted in ICTs tripping by LV side high set over current relay.

• It was noted that the current on HV side of ICT was 1.2 kA and LV side was 4.86 kA.

• PCSC Members pointed out that for a CT fault, 220 kV bus bar protection should have operated.

• SRLDC opined that HV side high set O/C should have tripped instead of LV side.

• APTRANSCO informed that by 30th May 2014, bus bar protection would be functional.

3.3 Grid Disturbance at 400kV Talaguppa Station on 06.04.2014

(i) Date and Time of event 06.04.2014 at 6.18 Hrs (ii) Location Talaguppa , Karnataka


400kV Talaguppa Substation, KPTCL



Triggering incident was tripping of 220kV Sharavathy-Talaguppa line-1&2. 400kV Hassan-Talaguppa and 400kV Nelamangala -Talaguppa tripped on over voltage. ICT-1 tripped on over flux protection.

(v) Load Loss 240 MW (vi) Duration of interruption 1 Hr 10 Minutes to 6 Hours 3 Minutes

(vii) Category GD 1

Deliberations:

• KPCL informed that due to disturbance at Sharavathy Generation Station (SGS), 220 kV Talaguppa – SGS line had tripped on over voltage.

• It was informed that at SGS, LBB mal operation affected the entire bus; timer was energized but tripped the other wing of the bus section; 250 V DC battery source was having positive to earth fault.

• KPCL informed that bus bar scheme along with LBB is being installed and it would be ready within 15 days and also informed that bus bar scheme installation has been done at RTPS.

• PCSC forum discussions focused on the frequent trippings at SGS due to DC earth fault.

• SRLDC enquired about the DC earth fault relay at SGS.

• SRPC stated that by 30th April, 2014, KPCL needed to submit the status of the action taken to remove the frequent DC earth fault issues at SGS.

• While informing that SGS is a 40 years old plant, KPCL said that the location of the DC earth fault could not be ascertained i.e. whether it is at the switchyard area or control room building area.

• It was noted that the power plant and switchyard use the same DC battery source and NTPC suggested that it is better to have separate DC source for switchyard and plant area.

• Forum felt that in the absence of DC earth fault relay at SGS, the DC testing kit could be borrowed from KPTCL and the panels could be tested for DC earth fault.

• SRLDC expressed concern over the repeated DC earth fault problem at SGS, and stated that if DC earth fault/disturbance happens again, they may be constrained to file a petition in the Hon'ble CERC.SRLDC also felt that that the grid cannot be jeopardized for the sake of a generator.

• It was noted that 900 MW generation loss at SGS would have cascading effect on the lines in the area.

• SRLDC and SRPC urged KPCL to rectify the DC earth fault at SGS by 15th May, 2014 positively without fail.

• SRLDC said that there needed to be a separate DC supply source for switchyard area.


Recommendations & Follow up

Ø SRPC Vide Lr No SRPC/SE-II/2014/2764-65 dt 01.05.14 (Annexure II) addressed a letter to Technical Director, KPCL for making necessary arrangement to ensure the source of DC earth leakage is identified and necessary remedial action is arranged.

Ø SRPC also requested KPCL to provide separate DC Sources for the generating station and the switch yard.

3.4 Grid Disturbance at Grid Disturbance at Kadra & Kodasalli

(KPCL) Generating Station on 15.04.2014

(i) Date and Time of event 15.04.2014 at 08:25 Hrs (ii) Location Kadra & Kodasalli, Karnataka


Kadra & Kodasalli 220 KV SS,KPCL


CVT blast in Nagjhari Kodasalli Line 1 lead to outage of Kadra a nd Kodasalli Generating stations

(v) Generation Loss Nil (vi) Duration of interruption 1 Hour 18 Minutes

(vii) Category GD 1

Deliberations :

• SRLDC informed that as the R-phase CVT failure was at Kodasalli, the line ideally should have tripped in zone-1 at Kodasalli and zone-2 at Nagjhari end with carrier aided trip.

• KPCL informed tha t as per the instruction from SLDC, both Kodasalli line CBs at Nagjhari end had been kept open. Due to this fact Kodasalli-Nagjhari line-1 tripped at Kodasalli end only. SRLDC informed that the fault was cleared at Kodasalli in time.

Kadra Kodasalli

Nagjhari Kaiga

Post-fault Scenario:

Kadra Kodasalli

Nagjhari Kaiga

Pre-fault Scenario:


• SRLDC described that Kaiga-Kodasalli and Kadra-Kodasalli lines tripped at Kodasalli end in reverse zone (zone-4) and Kaiga-Kodasalli line tripped on Earth fault at Kaiga end. Thus, Kadra and Kodasalli 220 kV buses got de-energized.

• It appeared that high set over-current instantaneous Earth Fault tripping acted at Kaiga end on Kaiga -Kodasalli line. It was noted that high set over-current instantaneous setting was not yet changed as per the earlier recommendations of the PCSC forum.

• NPCIL-Kaiga informed that it had obtained approval from Head Quarters and the change was being implemented.

• Forum took serious view of the issue and advised that the settings be changed/ revised immediately by availing shutdown of the line.

3.5 Grid Disturbance at Grid Disturbance at Kadra & Kodasalli

(KPCL) Generating Station on 18.04.2014

(i) Date and Time of event 15.04.2014 at 08:25 Hrs (ii) Location Kadra & Kodasalli, Karnataka


Kadra & Kodasalli 220 KV SS,KPCL


220kV Buses at Kadra & Kodasalli got de-energized

(v) Generation Loss 40 MW (vi) Duration of interruption 26 Minutes (vii) Category GD 1

Deliberations:

• It was informed that Kaiga -Kodasalli and Kaiga-Kadra lines had tripped on Earth Fault in B-phase at Kaiga end.

• Due to fault on Kodasalli-Nagjhari line-2, unit#3 got tripped at Kodasalli and the two lines (1&2) tripped at Kodasalli end.

• Kaiga-Kodasalli and Kadra-Kodasalli lines tripped on reverse zone (z4) at Kodasalli end.

• PCSC forum took note of the issue and urged KPCL to check & review both the undesired operation of turbine protection for line fault and distance protection reverse zone (z4) at Kodasalli on priority basis.


Ø PCSC forum recommended KPCL to revise the high set over-current

instantaneous setting as per the PCSC recommendations at the earliest and the

same may be communicated to the PCSC forum for record purpose.


4 Grid Incidences in the Southern Region

The Grid Incidences that had occurred during March - April 2014 were discussed in the

PCSC meeting. The details (deliberations and recommendations) of the Meeting are

enclosed herewith as Annexure - III.

5 Compliance Measures with regard to orders of Hon’ble CERC 5.1

Petition No. 146/MP/2013 with I.A. 36/2013 Order Dt 20.02.2014 Petition No. Order/ROP Date

Order Description Report to be submitted by respondents.

Periodicity of Reporting to CERC

Petition No. 146/MP/2013 with I.A. 36/2013 O: 20.02.2014

Accordingly, we direct the respondents to implement the works as mentioned in Phase-I and Phase-II by 1.5.2014 and 1.9.2014 respectively.

To SRPC/ SRLDC

Phase I : by 01.06.2014 Phase II : Bimonthly status report

Petition No. 146/MP/2013 with I.A. 36/2013 O : 20.02.2014

Commission's directions and ensure compliance of Regulations 5.2 (r) of the Grid Code and report instances of non-compliance to the Commission.

SRPC/ SRLDC

As and when non-compliance occurs. Could be done on monthly basis.


Provisions of Regulation 5.2(e) of the Grid Code and CEA Grid Standards.

SRPC/ SRLDC

As and when action plan for revival to be finalized.


On this issue, we direct all RPCs to formulate patrolling protocol/guidelines by 1.6.2014.

SR Constituents

01.06.2014

Deliberations:

• In the PCSC meeting the timely compliance of the above was highlighted. The periodicity of Reporting was discussed and the constituents were requested to subm it the progress of implementation to SRPC and SRLDC as specified in the Hon'ble CERC Order dated 20th February.2014.


• The issue regarding non-furnishing of Trip Analysis Report, EL, DR etc was highlighted. SRPC has taken up the issue under Clause 1.5 of IEGC vide letter dated 10.04.14 and 16.04.14. It was pointed out that the above reports were to be uploaded on SRLDC web application within 24 hours as mandated in IEGC/CEA Regulations.

5.2 Petition No. 167/ Suo- Motu / 2012

Petition No. Order/ROP Date



Petition No. 167/Suo-Motu/2012 O : 22.02.2014

RPCs shall ensure that the approved philosophy is adopted by all users.

SR Constituents

As and when


We direct ISTS licensees to submit details of updated distance protection relay setting of all inter-regional lines with POSOCO & RPCs.

PGCIL & ISTS Licensee latest by 04.04.2014

To be collected


The Commission directs all SLDCs to install/activate sound recording system in their control rooms within three months from the date of issue of this order.

SLDCs To be followed

Deliberations:

• In the PCSC meeting the timely compliance of the above was highlighted.

• The periodicity of Reporting was discussed and the constituents were requested to submit the progress of implementation to SRPC and SRLDC as specified in the Hon'ble CERC Order dt 22.02.2014.


5.3 Petition No. 263/MP/2012

Petition No. Order/ROP Date



Petition No. 263/MP/2012 O : 19.12.2013

SRLDC and SRPC of implementation of quantum of relief by AUFR as per table above and proper functioning of df/dt relays within one month of issuing this order.

Certified copy sent to SR constituents

-

Petition No. 263/MP/2012 O : 19.12.2013

SLDCs are directed to map these relays on the SCADA system within three months of issuance of this order. SRPC/SRLDC shall submit a compliance report in this regard within four months of issuing this order.

CERC Before 19.04.2014

Deliberations:

• In the PCSC meeting the timely compliance of the above was highlighted.

• The periodicity of Reporting was discussed and the constituents were requested to submit the progress of implementation to SRPC and SRLDC as specified in the Hon'ble CERC Order dt 19.12.2013.

• The Letter submitted to CERC regarding the compliance is enclosed herewith as Annexure IV .


6 Implementing / Reviewing the Special Protection Schemes (SPS)

6.1 Review of SPS : 765 KV Raichur Sholapur Line-Additional Logic

The SPS logic review as submitted by NLDC is enclosed he rewith as Annexure V Triggering criteria for SPS(implemented

SPS action implemented

Proposed revision in SPS

Remarks

765kV Sholapur-Raichur flow > 800 MW: SPS-1

Suggestion : SPS should trigger when flow on 765 kV Sholapur-Raichur S/C line crosses 1000 MW from Sholapur towards Raichur and remains above 1000 MW for 2.5 seconds. It should also act instantaneously when the power flow crosses 1500 MW.

Dp/Dt > 400 MW/Sec

Suggestion : New Principle to be worked out by CTU. Presently Dp/Dt blocked due to mal operation on three occasions. Flow>800 MW and Line trips SPS with 500 MW load shedding in SR.

Over Current Protection

Suggestion : Only to act if power flow is from Sholapur to Raichur.

Total flow on 765 kV Sholapur-Raichur 2 x 765 kV S/C lines crossing a preset value, say 800 MW in Sholapur to Raichur direction sensed both at Sholapur and Raichur.

Western Region 500MW Gen Back down JPL - 350 MW KSK - 150 M W DB power=0MW

Western Region 800 MW Gen Back down More generators such as Lanco Amarkantak, KWPCL, BALCO, JPL Ext, NSPCL etc. must be covered in W3 area so that 800 MW relief is available under all conditions.

Rationale: SPS should not operate for the first swing arising out of generating unit trip in Southern Region and antecedent flows from Sholapur to Raichur is less than, say 400-500 MW, towards Southern Region. It has been observed from Synchrophasors data that the first spike is typically 115- 125% of the generation lost in Southern Region and


oscillations of the order of 0.20 Hz are observed. Further, one argument cited by generators towards inadequate relief is the low antecedent generation on these units. As this would be a highly probable scenario, SPS wiring may be done for more quantum so that 800 MW relief is always available.

Increases in Flow on Raipur Wardha/ Wardha Parli/ Parli Sholapur Line

Load Shedding in Western Maharashtra if flow on Raipur Wardha line increases more 850 MW ( Earlier 800 MW) with time delay of 2.5 Sec. Or When line trips with flow of 750 MW (Earlier 650 MW).

Changes in Southern Region

Southern Region 500 MW Load Shedding T N - 146 MW Kerala - 125 MW Kar - 104 MW AP 125 MW

Southern Region No Change

Deliberations:

• The SPS logic as submitted by NLDC was discussed in the PCSC meeting.

• SRLDC explained the SPS modifications suggested by NLDC.

• Blocking the first power swing by increasing the time delay from instantaneous to 2.5 second for tripping, 300 MW additional generation back down in WR and 250 MW load shedding in WR modifications are suggested by NLDC.

• It was noted that the changes in SPSs as proposed by NLDC were balanced and involved minimal changes in SR.

• In response to PGCIL's query, SRLDC clarified that SPS would act only when SR imports and not while SR exports.

• TANTRANSCO pointed out that there were as many as 111 trippings on account of 765 kV line SPS operation.

• While replying to a query by PGCIL on load shedding details of SPS-7 (current > 800A), MS i/c said as per discussion in the Hyderabad meeting to trip KKNPP SPS Loads with O/C relay operation on Sholapur Raichur 765 KV line, a communication would be sent to NLDC to incorporate the same with existing 765 Sholapur Raichur


SPS.

• It was agreed that a subgroup meeting would be held to examine the issues raised by KSEB in response to NLDC's SPS .

• The PCSC forum agreed for the SPS proposal in principle and the same would be communicated to the NLDC.


Ø The PCSC forum agreed for the SPS scheme-1 as suggested by the NLDC and the same would be communicated to NLDC.

Ø The PCSC forum recommended for having a Sub Group meeting to deliberate on the issues raised by KSEB.

Ø SRPC Vide letter N o SRPC/SE-II/2014/3763 dated 30.04.2014 had sent the SR views regarding the SPS review as proposed by NLDC is sent (Annexure VI).

Ø The Sub Group meeting to discuss the SPS issues raised by KSEB is scheduled on 28.05.2014 (Wednesday, the day prior to the 32nd PCSC )Annexure VII.

6.2 SPS for Kolar Hosur Line

Logic:

Contingency: One of 400kV Kolar-Hosur D/C line trips and flow on other Circuit > 850 MW

Action: Back down 500 MW import at HVDC Kolar and Shedding load in Tamil Nadu as per Trip Signal 2.

Deliberations

• It was informed that the SPS had been discussed in the OCC meeting.

• SRTS-II, PGCIL informed that the SPS would be implemented after discussing the financial issues of SPS in the Commercial Sub Committee.

• KSEB requested SRLDC to furnish the details of Loads identified for tripping while implementing the SPS.

6.3 Revising the Logic of SPS for Hosur S/S

Deliberations

• PCSC forum recommended that the scheme may be disabled but may not be dismantled. It may be put in place whenever one of the three ICTs is taken for maintenance.


6.4 SPS for PGCIL 400 KV Mysore and 400 KV Kalavindapattu S/S

Deliberations (as discussed in 94th OCC)

• It was informed that the above SPS issues had been discussed in the 94th OCC.

• It was agreed in the 94th OCC meeting to implement the SPS for Mysore ICTs by PGCIL and the quantum of relief would be given by SRLDC.

• Loading would be considered as 110% for alarm and 130% for trip. The ratio (flow on Kadakola - Kaniampetta & Drawal from Mysore ICTs) of loads to be shared between Karnataka and Kerala would be finalized by SRPC secretariat based on the one year data.

• The issue of extending the signal to Kaniampetta needed to be examined by PGCIL in coordination with KPTCL/KSEB.

• In respect of the implementation of SPS for Kalavindapattu ICTs, TANTRANSCO pointed out that the loadings of ICTs were not as projected by PGCIL and needed review. After deliberations, it was agreed that TANTRANSCO and SR-II PGCIL would furnish the loading pattern of Kalavindapattu ICTs to assess the need for SPS.

6.5 SPS for Kudankulam Nuclear Power Station

Ø The issue was discussed in detail in the 29th PCSC and in the Spe cial meeting held at SRPC on 17.03.2014. Letter dated 28th April 2014 from NPCIL is enclosed as Annexure VIII.

Deliberations

• KKNPP informed that they would carry out manual ramp down at the rate of 50 MW/minute and it would take around 5 to 6 minutes for 300 MW ramp down.

• SRLDC expressed apprehension on 400 kV S/C KKNPP – Madurai line (twin moose conductor) withstanding full power during the ramp down period of 5 to 6 minutes.

• SRLDC & PGCIL desired that ramp down be carried out automatically through soft logic.

• KKNPP replied that whether manual or soft logic, the duration of ramp down would be same and in case of manual only operator response time (of around two minutes) delay may be there.

• KKNPP said that they arrived at the manual mode of ramp down after a lot of discussions at various level including with Russian engineers. The ramp down plan was based on the NLDC document. The factors related to nuclear fuel failure concept and nuclear physics had been considered while preparing the plan;

• In principle , soft logic has been accepted and KKNPP would try to implement it in parallel with manual logic in consultation with Russian engineers in due course.

• SRLDC stated that evacuation cannot be assured under this condition. It is not clear whether the line could withstand or not; it was noted that the twin moose would carry around 852 MW.

• KKNPP informed that the KKNPP-Madurai line could be upgraded to quad moose


conductors so that it can handle adequate power from KKNPP plant.

• NPCIL stated as discussed in the 36th Standing Committee Meeting on 4th September 2013, the termination point from Tuticorin Pooling station from KKNPP should also be ensured.

Recommendation:

Ø The PCSC forum recommended for manual ramping down of KKNPP units at the rate of 50 MW/minute. NPCIL, KKNPP is advised to go for automatic ramping of units at the earliest (embedding the SPS with soft logic).

7 Single Phase Auto Reclosing Facility for KKNPP Lines

The issue was discussed in the OCC, PCSC meetings and the special meeting held at SRPC on 17.03.2014.

Deliberations

• It was informed that KKNPP had agreed in earlier meetings to implement 3-phase auto reclose with synchro check feature.

• KKNPP informed single phase auto reclose feature is under implementation in Rajasthan Atomic Power Station in NR.

PCSC Deliberations

Ø The PCSC forum advised NPCIL, KKNPP to implement the Single Phase Auto Reclose Scheme at the earliest and the same may be communicated to the forum.

8 Status of Pending Protection issues

Pending protection issues were discussed in the 30th PCSC meeting and follow up details are enclosed as Annexure –IX.

9 Phasing of Implementation of Protn. Audit Recommendations

The implementation of the Protection Audit recommendations needed to be as per the Hon'ble CERC directions (covered under item 5.1).

10 Tripping Incidents in the Southern Region

Tripping incidents that had occurred in the Southern Region during the month of February- March 2014 for which details not updated /submitted to SRLDC be updated at the earliest.

11 The issue of quantum of df/dt relief in SR

In the 29th PCSC meeting SRLDC informed that the df/dt settings in the Southern Region would be revised from the month April 2014 due to Synchronization of SR with NEW Grid.


Deliberations

• The PCSC forum decided to discuss the issue in detail in the next PCSC.

12 Submission of completed dynamic study data

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.

Deliberations

• SRLDC had submitted the pending details from the constituents.

• The pending units would be circulated in the agenda of the 32nd PCSC.

13 Informing configuration changes to PCSC forum

It was agreed in the PCSC forum that if any change in the system configuration ( i.e. addition of Generating Units, Capacitors, Reactors, LILO etc) are to be highlighted and brought to attention of PCSC forum during the PCSC Meetings . This would enable utilities to review their protection settings if any change in the adjoining utilities to have better protection coordination in the Southern Region.

All the constituents are requested to send the change in the configuration in their system if any to the PCSC forum on monthly basis.

14 Date & Venue of the next Meeting

• The 32nd PCSC meeting would be conducted on 29.05.2014 (Thursday) at SRPC Bangalore.

• The PCSC meeting would be preceded by the Sub Group meeting of PCSC on 28.05.14 (Wednesday).

MS i/c, SRPC thanked all the Members & participants for their active contribution in the Meeting.

*****

Rajan1

ANNEXURE I (1/5)

Rajan1

ANNEXURE I (2/5)

Rajan1

ANNEXURE I (3/5)

Rajan1

ANNEXURE I (4/5)

Rajan1

ANNEXURE I (5/5)

Rajan1

ANNEXURE II (1/1)

ANNEXURE III

1

I.Grid Incidences occurred in the Southern Region:31st PCSC Deliberations & Recommendations

SN Details of Event Date & Time

Reason 31st PCSC Deliberations & Recommendations Cate gory

1 400 kV SATTENAPALLI - SRISAILAM 2

15-Mar-2014 at 13:47 hrs

Transient fault in R-Phase PLCC Mal Operation. SRLDC informed the constituents (APTRANSCO) to submit the station Event logger instead of sending the Relay Event logger.

GI -2

2 400 kV NEYVELI TS 1 (EXP) - TRICHY

24-Mar-2014 at 4:20hrs

B phase to earth fault. DT received from Neyveli end

It was suggested to check the protection settings. GI-2

3 400kV VTPS-Malkaram line-1 & 2

27-3-2014 at 13:18 hrs

400kV VTPS-Malkaram line-2 : R-phase to ground fault had occurred in line. Line did not auto reclose and tripped. 400kV VTPS-Malkaram line-1 tripped at Malkaram end only due to direct trip receive.

• APGECNO clarified that SOTF logic is not using any CB input signal, and is based on the dead bus closing philosophy.

• APGENCO informed that mal operation of SOTF prevented auto reclose (A/R) of the VTPS-Malkaram line -2 and the faulty SOTF relay has been rectified.

• TNC switch, which is suspected to have mal operated whenever tie-CB is involved, was replaced and it is under observation.

GI-2

08-04-2014 at 12:08 hrs

400kV VTPS-Malkaram line-1 tripped on a B-phase to earth Fault. Line did not auto reclose. 400kV VTPS-Malkaram line-2 tripped at VTPS end only

13-Apr-2014 at 23:17hrs

Transient fault in B phase

4 400kV VTPS-Malkaram line-2

14-Mar-2014 at 12:02 hrs

Transient fault in R-Phase.

Rajan1

(1/5)

ANNEXURE III

2

5 400 kV HASSAN - UPCL 2

28-Mar-2014 at 12:52hrs

From D.R of UPCL end it is observed that earth fault protection of line got operated which resulted in tripping of line.

• It was noted that Hassan – UPCL lines tripped on account of back up earth fault protection.

• UPCL said that more line trippings (usually between 12.00 and 3.00 PM) are due to bamboo/ rubber trees on the right of way.

• UPCL said that relays would be tested by M/s Alstom shortly.

• Effective patrolling of the line would be carried out as decided in the meeting held by concerned utility officials.

• PGCIL suggested that as many trips are attributed to high resistance fault, carrier aided directional scheme is required.

• UPCL to adopt IDMT characteristics for back up earth fault protection.

GI-2

6 400/230 kV ICT 1 AT ALAMATHY

30-Mar-2014 at 19:55 hrs

B phase L.A failed in 230kV Koratur line. 400/230kV Auto Transformer-2 also got tripped during the event

TANTRANSCO informed that Buchholz relay of ICT-2 got operated because of mal operation of Buchholz relay due to suspected jerk/shock.

GI-2

7 Tripping 220kV lines and Unit#7 & 8 at Sharavathy hydro station

06-Apr-2014 at 06:18 hrs

The triggering incident was tripping of 220kV Sharavathy-Talaguppa line -2 which tripped on fault. 220kV Sharavathy-Talaguppa line -1 tripped from Sharavathy end due to reported mal-operation of LBB relay at Sharavathy end. 220kV lines to Shimoga and Sirsi also tripped along with running units#7 and 8. Unit # 1,2,3,4, 6 & 9 went on house load

Discussed in detail in the minutes at item No 3.3 Grid Disturbance at 400kV Talaguppa Station on 06.04.2014.

GI-1

8 Tripping of 400kV Kolar - TVVLM line & 400kV

11-Apr-2014 at 20:18

B phase CT failure in 400kV Spdr- Tiruvalum line at Tiruvalum end which resulted in bus fault. Complete outage occurred as lines were

• It was noted that Kolar-Sriperumbudur line has LILO at Tiruvalum.

• SRLDC said that though Tiruvalum- Sriperumbudur

GI-2

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Sriperumbudur- Tiruvalum line

connected to one 400kV bus. tripping was in order, Tiruvalum-Kolar line would not have tripped. The tripping of Tiruvalum-Kolar line was due to the absence of tie -CB at Tiruvalum.

• It was noted that as of now, Kolar and Nellore (1 & 2) feeders are being operated without tie-CB in the one and half breaker scheme at Tiruvalum.

• PGCIL informed that tie-CBs for Nellore-1 & 2 lines are being taken into service first time today i.e. 29.04.2014.

• SRLDC expressed concern over PGCIL operating the 400 kV lines without tie-CBs and not informing Regional Load Dispatcher and stated that the absence of tie-CBs came to its notice in the PCSC meeting only.

• It was stated by SRLDC that line operation with single CB is against the protection philosophy.

• MS i/c, SRPC also expressed his concern over the operation of Line with single CB and not informing the same to SRLDC. The Regional Load Dispatcher would not be kept in dark regarding tie-CB and it is not good for the system. He urged PGCIL to keep SRLDC informed of if any change in the scheme or absence of power system element /equipment.

9 Tripping of 400kV Vallur-Kalavindapattu line -1&2

13-Apr-2014 at 21:06 hrs

Failure of B-Phase Current transformer in Vallur Main bay at Kalavindapattu substation which resulted in a bus fault in 400kV bus-2. 400kV Vallur-Kalavindapattu line-2 also tripped during the incident.

• PGCIL informed that the tripping occurred due to possible configuration problem with LBB which is having two features – common trip (for within bay) and inter-trip (for all bays) and the problem had been rectified.

GI-2

Tripping of 400 K v KLVDPT - VALLUR 1

14-Apr-2014 at hrs

Line failed due to auto reclose at Vallur end

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10 Tripping of 400 kV NCTPS - VALLUR 1

05-Apr-2014 at 6:51 hrs

R-phase to earth fault • NTPC informed the forum that fog is more in this year and the fog is common problem during April-June.

• NTPC further informed that hotline washing of insulators is being carried out during this period at their plants.

• TANTRANSCO informed that as both Vallur and NCTPS power plants at a short distance, auto-reclose (A/R) may not be required.

• It was informed that NCTPS-Vallur lines are provided with line differential protection for main-1 and distance protection for main-2.

• SRLDC stated that auto-reclose (A/R) scheme has to be enabled both at NCTS and Vallur plants.

Tripping of 400 kV NCTPS - VALLUR 1

08-Apr-2014 at 3:30 hrs& 21:06

Transient fault in line in R phase and B-phase

Tripping of 400 kV NCTPS - VALLUR 2

08-Apr-2014 at 20:52 hrs

Transient fault in B-Phase

400 kV NCTPS -VALLUR 1

09-Apr-2014 at 19:47 hrs


400 Kv NCTPS - VALLUR 2

11-Apr-2014 at 19:58 hrs



13-Apr-2014 at 4:24 hrs

Transient fault in R phase


13-Apr-2014 at 4:59 hrs

Transient fault in R phase

11 Tripping of 220kV Kaiga-Kadra and Kaiga-Kodasalli lines

15-Apr-2014 at 08:25 hrs

Lines tripped during fault in wave trap of 220kV Kodasalli-Nagjheri line-1 at Kodasalli end.

Discussed in detail in minutes at item No 3.4 & 3.5 Grid Disturbance at Kaiga Kodasalli Gen Station.

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II. Grid Incidences (Tripping of Lines on Single end) occurred in the Southern Region:

31st PCSC Deliberations & Recommendations

SN Details of Event Date & Time Reason 31st PCSC Deliberations & Recommendations

Cate gory

1 400 kV GHANAPUR - MAMIDIPALLY

20-Mar-2014 at 15:20 hrs

Line tripped at Ghanapur end only on Direct trip receive The PCSC forum requested APTRANSCO/PGCIL to

check the PLCC system at their respective ends. GI-2

2 400 kV CHITTOOR - SPDR

20-Mar-2014 at 18:20 hrs

Line tripped at Chittoor end only on direct trip receive The PCSC forum requested SRTS II,PGCIL to check the

relay settings.

GI-2

3

400 kV KUDAMKULAM - MADURAI

22-Mar-2014 at 00:51 hrs and 17:10 hrs

Line tripped at Kudankulam end only.

It was informed that there was problem in DC control circuit and the same was rectified.

GI-2

4 400 kV GOOTY - NELAMANGALA

29-Mar-2014 at 07:27 hrs

line tripped at Nelamangala end only It was informed that the maloperation of THR relay (Distance

Protection ) GI-2

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ANNEXURE IX

1

Status of Pending Protection issues

a. Recommendation to be complied by December 2013 SN

Recommendation The meeting in which the issue was Discussed

Anticipated date of completion

Agency Status 31st PCSC Deliberations

1 NPCIL,KPCL and KPTCL in coordination to review the protection settings at Kaiga Corridor

24th PCSC (26.09.2013 )

Dec-13 NPCIL, KPCL

implemented

Kaiga, vide Lr No NPCIL/KGS1&2/TSS/2014/S/296 dt 09.05.14 informed that protection relay Settings for 220 KV lines emanating from Kaiga were revised (Annexure X).

b. Recommendations to be complied by February- 2014

SN




1 BUSBAR PROTECTION AT KAYATAR 110KV SUBSTATION

21st PCSC held on 25.06.2013

Feb-14 TANTRANSCO

Pending TANTRANSCO informed that the 9 bays had been provided with relays and the delay is due to Electioneering process and would be completed by end of May 2014.

c. Recommendations to be complied by April 2014

SN Recommendation The meeting in which the issue was Discussed



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1 Bus Bar protection Scheme at Ragalapadu Substation

26th PCSC (21.11.2013)

Mar-14 APTRANSCO

pending APTRANSCO informed that the scheme was tied with Phase I of implementation.

2 PROVIDING DR AND EL-MAMIDAPALY

23rd PCSC held on 27.08.2013

Feb-14 APTRANSCO

Pending APTRANSCO informed that issue would be resolved within the agreed time.

d. Recommendations to be complied by May – 2014




1 48 V DC SUPPLY REDUNDANCY NOT AVAILABLE-EDAMON

17th PCSC (26.02.2013 )

May-14 KSEB Pending KSEB to update the status.

2 EARTH PITS at EDAMON

17th PCSC (26.02.2013 )


3 Main2 distance protection for EMPC#1 feeder not available - Edamon

17th PCSC (26.02.2013 )

May-14 KSEB - KSEB to update the status.

4 DG set at Edamon 17th PCSC (26.02.2013 )


e. Recommendation to be complied by June - 2014 SN



Agency

Status 31st PCSC Deliberations

1 The Main I and Main II Protection of Different make-Sharavathy


June-14 KPCL Pending KPCL to update the status.

2 a. APGENCO to consider usage of relays of different make for Main –I and Main II distance

27th PCSC

Yet To be reported

APTRANSCO/APGENCO

Pending APGENCO to update the status.

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protection for KPTS- Managuru line-2. Relevant APTRANSCO b.APTRANSCO to review distance protection settings of KPTS- Managuru line-2 as it tripped for fault in KPTS- Managuru line-1. c.APGENCO to review reverse distance protection settings of KPTS- Shapurnagar Line. d. APGENCO to enable DEF Back Up protection in all lines emanating from KTPS. e. APGENCO to enable IDMT characteristics for GTs and ICTs at KTPS which is to be coordinated with primary protection. f. APGENCO to review the Overload settings of Unit 4 g .DR at Khammam Substation to be time synchronized with GPS h. APGENCO to review bus bar protection settings.

f. Recommendations to be complied by Aug 2014




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1 Synchronizing Facility at Hubli.

17th PCSC (26.02.2013 )

Aug-14 KPTCL

Completed .to be tested

Synchronizing facility is provided at SRS Hubli station. Black start restoration procedure is to be tested in coordination with KPCL.

g. Recommendations to be complied by Sep - 2014

S N Recommendation The meeting in which the issue was Discussed



1 Replacement of OLD CBs at Sharavathy


Sep-14 KPCL Pending KPCL to update the status

2 COMPLIANACE OF 3RD PARTY AUDIT REPORT -Sharavathy

17th PCSC -25th PCSC (26.02.2013 to 22.10.2013)

Sep-14 KPCL Pending KPCL to update the status

h. Recommendations to be complied by Nov 2014 SN




1 •As the Plant was more than 25 years old, all yard equipment need to be replaced. •Modification of Bus Scheme to be carried out. •The PCSC forum recommended for the modification of Bus Bar protection scheme at Idukki Substation. In the event of bus fault the entire substation should not be affected. This would improve the reliability and security of the Idukki Hydro Generating station.

26th

PCSC

Nov-14 KSEB Pending KSEB to update the status.

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i. Recommendation to be complied by Dec 2014 SN




1 ONLY ONE BUS IS AVAILABLE, TRANSFER BUS SHALL BE PROVIDED -EDAMON

17th PCSC (26.02.2013 )

Dec-14 KSEB Pending KSEB to update the status.

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SOUTHERN REGIONAL POWER COMMITTEE Minutes of the Protection Coordination Sub-Committee€¦ · ·...

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