Southern Regional Power Committee (SRPC) · PDF fileSouthern Regional Power Committee (SRPC) ... KPTCL had earlier informed that the Power System Study Group ... KPTCL Zonal Chief

Southern Regional Power Committee (SRPC) Bangalore

Minutes of the 73rd meeting of the Operation Coordination Sub-Committee (OCC)

of SRPC held at Bangalore on 11th July, 2012

1. Introduction

1.1 The 73rd meeting of the Operation Coordination Sub-Committee was held at

Bangalore on 11th July, 2012. The list of Participants is given at Annexure - I.

1.2 Shri S.R.Bhat, Member Secretary i/c, SRPC welcomed the Members & other

participants to the 73rd OCC Meeting. He said that during the month of June 2012,

the PLF of Mettur TPS and Kakatiya –I stations had exceeded 99%. Mettur merited

appreciation for having achieved high PLF despite the recent fire accident. He said

that on account of poor/delayed South West monsoon to date, the energy storage in

the hydro reservoirs of Southern Region was less to the tune of about 2500 MU as

compared to the position last year. He suggested that on account of the depleted

hydro storage position, reworking/rearrangement of planned outage of thermal units

may need to be adopted to tide over the loss in availability.

1.3 MS i/c placed on record the exemplary contribution of Karnataka in continuously

adhering to grid discipline and for not receiving any violation messages during the

month of July 2012. He added that TN had received one Type ‘C’ message during

the month. Further, as per clause 1.5 of IEGC, the issue regarding Low voltage

conditions prevailing at Sriperumbudur. Kalvandipattu, Udumalpet, Trichy, Bangalore

and Mysore had been taken up with the utilities. The issue regarding overdrawal at

low frequency had also been taken up with Kerala and AP.

1.4 MS i/c along with OCC Members complimented NTPC Simhadri for having initiated

effective measures to achieve improved MVAR absorption and contain high voltages

in that area. He informed that the tap position of Generating Transformer of unit 3

had been changed by NTPC to effect the increased Q absorption within the

capability curve of the machine. NTPC Ramagundam’s improved Q absorption was

also noted and appreciated.

Minutes of the 73rd OCC Meeting of SRPC held at Bangalore on 11.07.2012

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1.5 MS i/c requested Shri A. Balan, Superintending Engineer to take up the Agenda

Points of the meeting and accordingly the same were taken up for discussion.

2. Confirmation of the Minutes of the 72nd Meeting of OCC of SRPC held on 11th June, 2012

The Minutes of the 72nd OCC Meeting were confirmed with the following amendments:

a) Page 4 - in item 3.1.2, second last line, the words – “derailment of coal wagons” shall be deleted.

b) Page 28, in item 5.5.1, the last column heading, “May-2011” to read as “May- 2012”.

3. Major Issues

3.1 Shutdown of Talcher units/Simhadri DC Declaration

3.1.1 The following had been noted in the earlier Meetings:

a) AGM, Talcher, NTPC had informed that OSPCB was monitoring the situation at Talcher, NTPC was carrying out the activities as per schedule. The representatives of OSPCB were also regularly visiting the site. As informed earlier, the clearance to operate the units was however likely to be received for only three months at a time. OSPCB had accorded permission to operate Talcher Stage-II units till 31st March 2012.

b) In the 70th OCC meeting, NTPC informed that during the last week of March-2012, an OSPCB team had visited the Talcher plant and was satisfied with the compliance measures. NTPC thus hoped that the plant would obtain necessary extension shortly. During deliberations on this issue, it was again noted that less DC was being declared in real time compared to day ahead DC thus leading to blocking of the margin available in the corridor. SRLDC contended that in view of varying DC declaration by NTPC, they were not in a position to accurately predict the margin availability for STOA transactions. NTPC said that though they had been furnishing realistic DC, at times on account of usage of coal from three different sources and blending with foreign coal, it was extremely difficult to predict the quality of coal in advance and give matching DC. MS i/c recalled that a meeting in this regard with NTPC officials had already been held at Hyderabad. After discussions, OCC suggested that NTPC may consider reduction of the DC so that the corridor bandwidth could be fully utilized in view of the fact that the states were reeling under huge power shortages and were eager to import more power.


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c) In the 71st OCC meeting, NTPC had maintained that the efforts were on to obtain the extension. SRLDC had stated that it was observed that the generation in NTPC Simhadri II was less than the DC declared by NTPC. SRLDC was declaring the ATC margin to Power Exchanges considering the zero revision DC declared by NTPC Simhadri II Unit 3. They had requested NTPC to declare realistic DC so that the margin available could be utilized by the constituents for power purchase through the market in order to meet the load generation balance. NTPC had been requested to initiate appropriate measures to address these issues.

d) In the 72nd meeting NTPC had informed that the plant was being visited by OSPCB officials regularly. In the review meetings held so far, no adverse comments had been communicated by OSPCB. OCC noted that though it was appreciated that DC declaration was NTPC’s prerogative, ATC was getting blocked due to higher DC that was not realized finally. SRLDC explained that as compared to day ahead DC, if the variation due to revised DC was 200 – 300 MW or more, then it would impair grid operation. However, if the DC variation quantum was around 20 – 30 MW, then it could be adjusted and managed by the SRLDC load despatcher. SRLDC said that they were expecting generators to take adequate care during DC declaration. TN wanted to know how DC could be raised upward when outage of elements was declared. SRLDC informed that on 10th June 2012, the day prior to the OCC Meeting, DC had been revised upward from 1300 to 1600 MW and consequent to this SRLDC had to curtail PX transactions.

3.1.2 In the meeting NTPC informed that the clearance from OSPCB was

expected soon.

3.2 Tripping of HVDC Bhadravathi

3.2.1 The following was noted in the earlier Meetings:

a) The issue regarding tripping of HVDC Bhadravathi was deliberated in the 64th OCC Meeting. The issue had also been discussed in a Special Meeting held at Mumbai on 29th July 2011 with participation from Power Grid, WRLDC, SRLDC, WRPC & SRPC. It was noted that PGCIL had informed that the OEM (M/s ALSTHOM) had recommended that flow should not be more than 800 MW on a sustained basis. PGCIL had suggested the following immediate possibilities for reducing the power oscillations:

i) Power oscillation damping feature of HVDC Bhadravathi to be made on - Already taken in service, however further study was being carried out by PGCIL to fine tune its setting.

ii) PSS tuning at NTPC Ramagundam needs to be taken up.

The issue regarding implementation of measures/steps as finalized in the Special Meeting held at Mumbai on 29th July 2011 was taken up with WRTS-I & SRTS-I vide letter dated 12th September 2011. It was noted


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that any decision regarding restricting the flow upto 800 MW needed to be taken up by higher forum.

b) In the 65th OCC Meeting PGCIL had informed that a letter dated 8th November 2011 had been addressed to SRPC giving point wise status of the issues pertaining to SRTS I, POWERGRID, which were discussed in the Special Meeting in Mumbai. This related to simultaneous measurement of harmonics and provision of web based video facility etc. MS I/c, SRPC had informed that in response SRPC had addressed a letter dated 9th November 2011 to POWERGRID. It was learnt that after discussions with M/s Areva, certain modifications in the settings had been suggested/carried out. He had therefore requested POWERGRID to furnish the status in this regard.

c) In the 69th OCC meeting, SRLDC had informed that they had sought high resolution data in respect of all the units of Ramagundam to analyse the hunting phenomenon when the power flow on HVDC Bhadrawathi is increased from 900 MW to 1000 MW. The data from NTPC was awaited. SRLDC also stated that before the proposed synchronization of NEW and SR grid by the year 2014, PSS tuning at Ramagundam must be in place. MS i/c had said that the outcome of the study carried out by M/s Areva as mentioned above could be informed to the forum. He requested that the concerned division at POWERGRID Corporate Centre could be apprised in this regard by SRTS – I.

d) In the 70th OCC meeting, SRLDC had informed that they were in receipt of data from NTPC in response to the discussions on this subject in the 69th OCC meeting. As inter-regional control area oscillations were involved, the data needed to be sent to other RLDCs for analysis. SRLDC further informed that it did not have the necessary expertise for analysis of this data. It had suggested that the System Study Sub Committee or Subject Experts could decode and interpret the data for further progress.

3.2.2 MS i/c informed that the related issue had been discussed in the 20th WRPC

meeting held on 18th May 2012. It had been decided in the WRPC meeting that

WRLDC shall share the data of oscillations observed by them with MSETCL and

POWERGRID and actions of the controllers at that time shall also be studied

before deciding further course of action. MSETCL had assured that whatever

appropriate action required on the HVDC Chandrapur – Padghe shall be taken.

It would therefore be prudent to await the outcome of the above mentioned

studies.

3.3 SPS for 400 KV Hiriyur – Nelamangala D/C Line



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a) KPTCL had earlier informed that the Power System Study Group of KPTCL had been requested to study and analyse the load flow conditions consequent to the commissioning of the following lines and units:

i) 400 KV BTPS – Hiriyur DC line

ii) 220 KV Hiriyur – Gowribidanur line

iii) 2 Nos. 500 MW units at BTPS

b) In the 67th OCC meeting, KPTCL had been requested to expedite the issue. It was informed by KPTCL that the SPS was being worked out in consultation with RT, KPTCL Zonal Chief Engineer, Bagalkot, JSW and KPCL. Further, GM, SRLDC had stated that the SPS on 400 KV Hiriyur – Nelamangala D/C Line was needed to be in place before the commissioning of the second unit of Bellary TPS.

c) In the 69th OCC meeting, Karnataka had informed that the second unit of BTPS was likely to come up by 2nd or 3rd week of March-2012. SRLDC reiterated that without SPS in place for the 400 KV Hiriyur – Nelamangala line, the COD of the new unit would not be possible. SRLDC had said that all new generating units must be with RGMO features. It was suggested by the forum that a check list of the requirements could be prepared by SRLDC and circulated to the Generators.

d) In the 70th OCC meeting, KTPCL informed that tower-to-tower inspections were being carried out and the Hiriyur – BTPS line was likely to be ready in a couple of days. The COD of BTPS Unit II was expected in April-2012. The SPS will be implemented soon after the commissioning of 400 KV BTPS – Hiriyur line

3.3.2 It had been noted in the 72nd OCC meeting that the SPS scheme was under

active implementation by KPTCL. It was informed that the remaining pending

works would be completed in about one month time. In the meeting, KPTCL was

again requested to complete the pending works at an early date, so that the SPS

could be made operational.

3.4 SPS for 400 KV Vijayawada – Nellore Line 3.4.1 The following was noted in the earlier Meetings:

a) In the 66th OCC Meeting, Andhra Pradesh had been requested to arrange a coordination meeting with IPPs & SRTS I for early implementation of SPS on Vijayawada – Nellore D/C 400kV line. It had been noted in the meeting that the issue was also discussed in the 18th SRPC Meeting held on 23rd December 2011. POWERGRID had informed that discussions with APTRANSCO/IPPs were underway.

b) In the 69th OCC meeting, SRLDC had brought to attention that at times, when AP was under-drawing TN & Kerala were over-drawing with the loading on 400 KV Vijayawada – Nellore lines being about 590 MW per circuit. It was noted that the implementation of the SPS scheme was pending for considerable time. SRLDC further stated that in the 17th


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SRPC Meeting, it had been informed by AP that 400 KV Vijayawada- Malkaram line would be commissioned by February 12. AP stated that backing down instructions received from SRLDC during contingency were always being implemented. After discussions, it was resolved that the SPS scheme on 400 KV Vijayawada – Nellore lines would be implemented by 15th April 2012.

c) In the 70th OCC meeting, to a query from SRLDC, AP had informed the Members that the SPS related works were expected to be completed as per the target date of 15h April, 2012.

d) In the 71st OCC meeting, APTRANSCO stated that they were constantly pursuing the matter regarding SPS with the concerned IPPs in this regard. As already explained the IPPs had expressed that due to less gas availability the generation had reduced considerably. OCC however noted that the flow on the 400 KV Vijayawada- Nellore line continued to be high. One unit of SEPL had already been declared on COD. COD of Unit 2 of Simhadri II was also expected in the coming months. It was noted that the commissioning of 400 KV Vijayawada – Malkaram line of AP as well as Narsraopet 400 KV S/S had been getting delayed, thus adding to the congestion on the Vijayawada – Nellore corridor. After deliberations, it was decided to discuss the matter further in the forthcoming TCC/SRPC meetings, wherein this issue figures as an Agenda Item.

e) In the 72nd OCC meeting, SRLDC expressed concern and pointed out that the issue was more than two years old. MS i/c in his opening address had informed the OCC forum that this 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. The deliberations of this Sub Group would be put up to Special TCC for consideration

3.4.2 It was noted that a Meeting in this regard had been conducted on 5th July 2012.

It had been decided in that meeting that APTRANSCO would take up with IPPS

for immediate implementation of the SPS scheme in the present form which

would be an interim measure till identification of new generators and

implementation of any modified scheme. Another meeting in this regard was

also scheduled to be held on 18th July 2012.

3.5 Unit Tripping Issue at Talcher Kaniha on account of SPS Operation 3.5.1 The following was noted since 67th OCC meeting onwards:

a) AGM, NTPC had informed about the incident on 13th September 2011, when Unit 6 of Talcher had tripped on “HVDC Inter Trip Operation”. Unit No. 5 had also unloaded by 150 MW. In this regard, NTPC letter dated 28th December 2011 was also referred. It was indicated in this letter that NTPC had been asked by SRLDC to revise the DC based on the


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availability of balance two running units. Unit 3 was already under shut down for annual maintenance works. UI had got suspended from 55th to 57th block because the outage was caused by grid factors. Accordingly NTPC Talcher had requested for reduction in DC from 58th block at 900 MW based on the availability of two units.

b) MS I/c, SRPC had stated that ‘DC’ declaration was within the purview of NTPC while SRLDC would limit themselves to scheduling. NTPC units had tripped on account of fault on Talcher-Kolar links and thus DC should not get affected.

c) AGM, NTPC had said that they had sought revision in the logic of SPS 1000 operation. In the proposed logic, the flow on 400 kV Talcher – Rourkela line would also be considered along with the availability of lines. This matter had been taken up by NTPC Corporate Group with NLDC. In the proposed scheme, no unit tripping was envisaged and in the worst scenario unloading of all six units of Talcher (Stage I & II) was proposed.

d) AGM, NTPC had also said that in the above instance of tripping, the issue was different. The generation level at Talcher Stage II was less, while additional power was being wheeled through the Talcher – Kolar link. There was no facility in place to cut off the additional power from other sources in event of pole outage. Forced outages of Talcher Stage II units were thus taking place causing loss of generation, additional fuel oil consumption etc. He had said that some means had to be devised so that the availability of Talcher II units was not affected. Further, in case of such outages, the DC of Talcher Stage II units should also not get affected in any manner.

e) GM, SRLDC had said that in such an event, the time taken by the tripped unit to come back after the HVDC Poles come back may also need to be clearly defined.

f) It was informed by NTPC that the unit would normally take three hours’ time to come up after tripping. It was agreed by OCC that NTPC be allowed to continue with the declaration of DC (already made) for a period of three hours after the poles come back. Further NTPC would not be asked to revise the DC in the eventuality of unit tripping on account of SPS operation. The REA for September 2011 would be revised as per the prevalent DC declaration made by NTPC just before tripping of Unit 6 due to SPS operation.

g) GM, SRLDC had stated that SRLDC would come back on this matter in the next OCC meeting, since commercial and other implications were involved. Further he had stated that there was an important issue regarding DC declaration by Talcher Stage II. Less DC was being declared in real time compared to the Day Ahead DC leading to blocking of the margin available in the corridor.

h) MS I/c, SRPC had stated that this aspect also needed to be examined in a closer manner, especially in the current high deficit scenario, in which the corridors were already over booked and there was a requirement for


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curtailment. He had added that SRPC Secretariat were also having certain observations regarding the DC declaration of Talcher Stage II.

i) In the 68th OCC meeting, it was informed that a meeting subsequently conducted in this regard at Hyderabad on 25.01.2012 was attended by NTPC, SRLDC and SRPC secretariat. The observations of SRLDC (as stated in 67th OCC) were awaited. The revision of REA for September 2011 would be taken up after receipt of observations from SRLDC.

j) In the 69th OCC meeting, NTPC had contended that 3 hours time period was required for bringing back the unit affected during the HVDC pole outage. Additional 7 to 8 blocks are also to be provided for ramping up of the unit to full load. After discussions, it was agreed that NTPC would submit its written observations with respect to the SRLDC letter. The matter would be further discussed in the ensuing Meeting of Commercial Sub Committee.

k) In the 70th OCC meeting, NTPC requested for revision of REA for the month of September 2011 in respect of Talcher II, based on the approved methodology. TN requested that similarly messages to the constituents for overdrawal at low frequency (Type A, B & C) be curtailed during SPS operation at Talcher- Kaniha.

l) NTPC again raised the issue regarding revision of REA of September 2011. It was noted that the proposed methodology figures as an Agenda Item in the forthcoming TCC/SRPC meetings. Further action could be initiated only after conclusion of the TCC/SRPC meetings.

m) In the 72nd OCC meeting it was note that the issue figured in the 19th SRPC meeting, and the guidelines for scheduling of Talcher STPS Stage II during SPS operation were agreed with modifications as suggested by SRPC. SRPC Secretariat had also said that the guidelines may need to be reviewed periodically.

3.5.2 In the meeting, MS i/c informed that revisions in the REA for September-2011

would be carried out in due course.

3.6 Physical, Cyber Security in power supply

3.6.1 The following was noted in the earlier meetings:

a) In the 63rd OCC Meeting, it was noted that a meeting was taken by Member (GO&D), CEA on 9th August 2011 regarding Physical, Cyber Security in power supply. After detailed deliberations, it had been agreed that the activity of monitoring of Crisis Management Plan for countering the cyber attacks and its implementation including the Mock Drills, audits etc. by all the Power Utilities on a regular basis would be monitored by the Regional Power Committees. In the OCC Meeting, it was decided that all the constituents including RLDC/SLDC would furnish the status of measures taken to counter the cyber attacks in their system along with mock drills, audit etc.


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b) In the 65th OCC Meeting, MS I/c, SRPC had informed that detailed information as received from SRLDC had already been circulated in the earlier OCC meeting. He had said that information on similar lines needed to be furnished by the other constituents also. In this regard, letter dated 03rd November 2011 received from APTRANSCO had been circulated.

c) This issue was also discussed in the 18th SRPC Meeting held on 23rd December 2011. In the meeting, the constituents had been requested to furnish the necessary details so that monitoring could be taken up by the RPC forum.

d) In the 69th OCC meeting, MS i/c had informed that CEA had recently addressed letter dated 01st February 2012 stating that India Smart Grid Task Force (ISGTF) had requested to furnish the status in this regard. CEA had sought the action taken and the present status of preparation of Crisis Management Plan (CMP). Accordingly, the Constituents were requested to speed up the cyber security measures for their system. He also informed that TN had submitted certain details of implementation. A summary of the cyber security measures implemented by SRLDC were summarized and presented by SRPC to the constituents.

e) It was noted that AP, TN, and SRLDC had initiated certain cyber security measures and submitted the details to the forum.

3.6.2 In the Meeting it was noted that KPCL had submitted implementation details with

regard to cyber security measures. KPTCL and KSEB informed that efforts were

on to implement cyber security measures and details in this regard would be

duly informed.

3.7 Coal Stock Position

3.7.1 The following was noted in the earlier OCC meetings:

a) It was noted that issue regarding Coal Stock position and other associated issues was also deliberated in the 18th SRPC meeting held on 23rd December 2011. SRPC had suggested that generators maintain the coal stock position as per norms to avoid any loss of generation.

b) OCC had expressed serious concern over the low coal stock being maintained by the generating units. It was felt that higher forum needed to be again apprised of the situation to identify appropriate remedial action.

c) OCC had also expressed concern over NTPC not furnishing the requisite information in the format though all the generators of Southern Region were furnishing this information. OCC had again requested NTPC to furnish the information in the format given below:


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Coal Stock Position Generating Company: Month: ...................

Name of the station

Statutory Requirement

Minimum coal stock in the month

Coal stock as on last day of the month Steps

taken to supple-

ment stock

Time by which

position likely to improve

In lakh T

In no. of

days

In lakh T

In no. of days In lakh T In no. of

days

Signature: .......................

Designation: ……………….. Contact Tel. No:

d) In the 68th OCC meeting, MS I/c had said that as informed earlier the matter regarding coal supply had been taken up with M/s MCL and also with CEA. The reply received in this regard from M/s MCL had subsequently been circulated to the constituents.

e) In the meeting, KPCL informed that to supplement coal stock at RTPS and BTPS, tender had been issued for supply of 15.00 Lakh MT of imported coal.

f) TANTRANSCO informed that as per FSA signed by TANGEDCO with MCL & ECL, 11.26 LT (per month) indigenous coal had to be supplied to TANGEDCO during April 2012 to June 2012. Against this, 8.68 LT, 9.64 LT and 8.31 LT of indigenous coal had been received at the load ports during April 2012 and May 2012 respectively. The present coal stock in the three load ports are 0.71 LT. ECL had supplied 108 % of FSA quantity during June 12 while MCL had supplied only 70 % of the FSA quantity. Overall 74 % of FSA quantity (ECL&MCL) has been supplied during this month. All efforts were being taken for increasing the realization of indigenous coal from mines to TANGEDCO in the ensuing months. Regarding imported coal, purchase orders dated 30.03.12 had been issued to M/s. MMTC and M/S. MSTC for supply of 14 LT and 7 LT of imported coal to Ennore Port and VOC TUTICORIN Port respectively for the period from April 2012 to September 2012. M/s.MSTC had so far supplied 3.22 LT of imported coal against the contracted quantity of 7 LT and M/s.MMTC had supplied 1.72 LT of Contracted quantity of 14 LT.

3.7.2 Coal stock position published by CEA and submission by constituents:

a) It was noted that as per CEA norms, coal stock position is termed as critical (< 7 days) or super critical (< 4 days) of coal stock. The daily Coal stock position report as on 4th July, 2012 as downloaded from CEA website is furnished at Annexure - II. It was noted that the coal stock position in the following Thermal Stations was less than that for 7 days generation:


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STATE STATION DAYS

(< 7) REASONS

AP Dr. N.TATA RAO 2 Less receipt - MCL KOTHAGUDEM 4 Less Receipt RAMAGUNDEM 5 Less Receipt SIMHADRI 5 Coal Sup. for U-4 yet to start KA BELLARY 2 Coal Sup. for U-2 yet to start

TN NORTH CHENNAI TPS 4 Less Receipt

Orissa TALCHER STPS 4 Less Receipt

b) Information furnished by APTRANSCO, KPCL & TN is given in Annexure - III.

3.8 Facilitation of Inter-State/Inter-Regional transfer of power & utilization of IPPs/Operation of Talcher – Kolar HVDC Link


a) The constituents were being requested to furnish details of any requirement/surplus (quantum, period, time of day, tentative rates, etc.) along with details of contact person to enable SRPC to post this information on its website, to enable faster buyer/seller interaction.

b) In the 69th OCC meeting, Constituents had desired that extended-mode (i.e. 10 hours @ 2500 MW) of HVDC Talcher – Kolar link may additionally cover time required for ramping up and ramping down also. PGCIL had expressed its inability in this regard and stated that the outer limit for extended mode operation was 10 hrs which included ramping up and ramping down time also. SRLDC had informed that due to this requirement for ramping up and down, certain other transactions may get curtailed for few time blocks during the extended mode of HVDC Talcher-Kolar link. SRLDC had also said that that extended mode operation of 2500 MW for 10 hours on a daily basis was recently committed by POWERGRID before Hon’ble CERC without any time limits. After discussions, it had been agreed that this issue would be put up for deliberations in the ensuing TCC/SRPC Meetings.

c) The issue was deliberated in the TCC and SRPC meetings held on 31st May and 1st June 2012 respectively. After discussions, the SRPC committee had approved the Recommendations as follows.

i) The operation of Talcher-Kolar HVDC link from 1300 Hrs to 1700 Hrs would be at a level of 1800 MW upto 31st July 2012.

ii) For all the other time slots already agreed, the existing level of operation would continue.

iii) Monthly OCC would review the quantum for succeeding month of operation. First review would be in July 2012 OCC for the month of August 2012.


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3.8.2 Operation of Talcher – Kolar HVDC Link In the Meeting it was noted that operation of Talcher- Kolar HVDC link from 1300

Hrs to 1700 Hrs would be at a level of 1800 MW upto 31st July 2012. On a query,

POWEGRID stated that this limit would continue beyond July 2012 also in view

of the high ambient temperature prevailing at Talcher. In view of the hydro

storage position in the region, OCC requested POWERGRID to review the limit

and permit 2000 MW flow from 1300 Hrs to 1700 Hrs also. POWERGRID

informed that they would apprise their management of the request in this regard.

Bilateral energy exchanges

a) On a review of the bilateral exchanges made by the constituents and also by the embedded IPPs during June -2012, the following was noted:

i) Imports (inter-regional) were carried out by: Andhra Pradesh, Karnataka, Kerala, TN, Karnataka IPPs and Tamil Nadu IPPS.

ii) Imports (intra-regional) were carried out by: Andhra Pradesh, Kerala Tamil Nadu IPPs & Andhra Pradesh IPPs

iii) Exports (inter-regional) were carried out by: AP

iv) Exports (intra-regional) were carried out by: Karnataka IPPs, Lanco & Simhapuri.

b) Details of Energy interchanges between the constituent systems and exchanges with the other regions are given at Annexure – IV (as per PSP).

c) It was also noted that Andhra Pradesh, Karnataka, Kerala & Tamil Nadu had furnished the relevant details regarding energy exchanges through Power Exchanges (Annexure - V).

3.9 Generation Schemes scheduled for 2012 -13

a) Progress of generation schemes scheduled to be commissioned during 2012-13 was reviewed. The updated information as furnished by the constituents is given at Annexure - VI.

b) SRLDC presented the list of important generating schemes, transmission lines and generation evacuation lines under construction (Annexure - VII).

c) SRLDC again requested the constituents to furnish updated information in respect of these important elements/stations in the OCC Meeting. They said that this matter was being discussed in the OCC Meetings so that the states could identify and monitor all lines (ATS) which are to be necessarily available during unit commissioning to avoid evacuation bottlenecks at a later stage.


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d) It was noted that 400 KV VTPS-Malkaram line was likely to be ready by the end of July-2012.

3.10 Pump mode operation of Kadamparai and Srisailam

It was noted that Kadamparai machines had consumed about 30.3 MU in pump

mode during June-2012. TN was requested to examine the possibility of

increased pump mode operation to avail opportunities during any high frequency

conditions.

3.11 Minimum to Maximum demand ratio


a) It was requested that the constituents initiate all possible measures to ensure appropriate Demand Side Management and Energy Efficiency Programmes considering that there were sizeable energy and demand shortages in the States with capacity addition generally not matching with demand growth in addition to also limitations in possible import of power. MS I/c, SRPC informed that the SRPC/TCC were also appraised of the above in the recent meeting. The constituents were requested to come out with specific details of proposed new approaches to Demand Side Management so that these recommendations could be put up to TCC/SRPC. KPTCL had informed that ESCOMS had shifted a portion of the load from peak hours to off peak hours.

b) It was noted that Members were aware that the matter regarding wide variation between maximum demand and minimum demand was being regularly taken up with the constituents in the OCC Meetings.

3.11.2 The details of percentage variation between maximum and minimum demand for

the month of June-2012 are given below:

State Maximum to Minimum Demand Variation % Highest Lowest Average

Andhra Pradesh 30.97 17th(Sun)

6.19 24th (Sun) 13.99

Karnataka 30.81 19th (Tue)

12.80 7th (Thu) 19.70

Kerala 49.30 20th (Wed)

31.14 2nd (Sat) 41.18

Tamil Nadu 29.88 26th(Tue)

9.51 24th(Sun) 16.97

Puducherry 31.54 18th (Mon)

15.44 23rd(Sat) 21.26

Southern Region 23.93 18th(Mon)

9.06 24th (Sun) 13.30

Note: Highest and lowest have been computed from daily values over the month.


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3.12 LGBR forecasted figures vs. Actual Figures

It was noted that variations between actual and forecasted availability and

requirement LGBR figures were more than 10% in respect of the following States

during the month of June-2012: Forecasted Actual Deviation

from Actual %

Variation Reason

a b c=b-a d=c/a Andhra Pradesh Energy Availability (MU) 5,880 6,523 643 11

Demand Availability (MW) 8,989 10,826 1837 20

Due to peak summer domestic load increased Due to dry spell agricultural load increased.

Karnataka Demand Availability (MW) 6,201 8,066 1865 30

Purchases. Demand Requirement (MW) 7,710 9,108 1398 18

Due to delay in onset of rains. Energy Requirement (MU) 4,539 5,440 901 20

Kerala Energy Availability (MU) 1,252 1,660 408 33

Higher hydro utilization and purchases

Energy Requirement (MU) 1,531 1,698 167 11 Delayed monsoon Demand Availability (MW) 2,557 3,167 610 24 Purchases Demand Requirement (MW) 3,020 3,364 344 11 Delayed monsoon.

Tamil Nadu

Demand Availability (MW) 9,125 11,053 1928 21 Increased use of Hydro sources and power purchases.

3.13 MoP Generation Targets vs. Actual

Details showing more than 10% shortfall in gross generation with respect to MoP

target figures for June -2012 are tabulated below:

June-2012 (%)

Cumulative (%)

Reasons for shortfall (>10% in MU) in gross generation

Andhra Pradesh

Hydro -35 -41 Decreased inflow into reservoirs.

Private sector -25

Karnataka

Hydro -30 -21

Diesel -43 -45 LSHS shortage; Merit order constraints.

Kerala

Kayamkulam -100 -65 Merit order considerations.

Tamil Nadu

Hydro -59

Gas -21

Private sector -11


15

3.14 Forced outages of thermal units


a) MS I/c, SRPC said that in the 18th SRPC Meeting, the Generators were apprised of the concerns raised by the SR constituents, CEA, MoP etc. over the high quantum of forced outages.

b) OCC recommended that the planned/preventive maintenance be carried out as per the schedule to reduce the instances of forced outages.

3.14.2 OCC was apprised of the forced thermal outages of more than 24 hours duration

during the month of June-2012 (Annexure - VIII). It was noted that the forced

outages of thermal units had varied between 3.30 – 7.26 % during the month of

June -2012.

3.15 Prolonged outages


a) MS i/c, SRPC pointed out that Hon’ble Commission was also monitoring the instances of prolonged outages and hence requested the constituents to furnish the required information regularly to SRPC/SRLDC for further needful.

b) In the 73rd OCC meeting, the following was noted:

i) Kalpakka Bus Reactors II & III were out.

ii) 400 KV Kudankulam - Thirunelveli line II was under outage.

iii) 400 KV Kudankulam - Thirunelveli line I which was under outage from 23.03.2012 was revived on 09.06.2012

iv) Simhadri Stage II Unit I had high vibration (Technical deficiency of equipment) from 13.04.2012.

3.15.2 OCC was apprised of prolonged outages in Southern Region during the month of

June-2012 (Annexure - IX).

3.16 Generation levels at NPCIL Units

It was noted that this issue was deliberated in the earlier SRPC meetings wherein

NPCIL had informed that the generation level of SR NPCIL Units would be

maintained at around 65 - 70% due to fuel constraints. In the 19th SRPC meeting

held on 1st June 2012, NPCIL had informed that they could maintain a generation

level of around 70-75 % depending on fuel availability.

3.17 IPP Utilization OCC was also apprised of the PLFs of the IPPs operating in Southern Region

during the month of June-2012 (Annexure - X).


16

3.18 Generation targets for the year 2012 - 13


a) In the 67th meeting, the following had been noted:

i) MS i/c, SRPC had said that as already informed CEA had sought information regarding thermal generating units including IPPs for assessment and finalization of generation targets for the year 2012-13. The same had been communicated to the constituents vide letter dated 29th September 2011. He had requested that the information be communicated to CEA with a copy to SRPC Secretariat.

ii) The forecast figures for energy requirement and demand requirement for 2012 -13 had been circulated during the 64th OCC meeting. SRPC had requested the constituents to examine the figures and revert back with comments, if any, since the same was to be considered for the Annual LGBR for 2012 -13. He had also informed that a meeting had been convened by CEA at Bangalore on 20th January 2012 to discuss the issue further with the concerned utilities.

b) In the 68th OCC meeting, SE-I had said that a meeting was taken by CEA at SRPC on 20th January.2012 regarding finalization of the Annual Generation Targets for the year 2012-13. He had also informed that the Outage Plan for 2012 - 13 had been circulated and discussed in that meeting. The Outage Plan had been approved and had been hosted on SRPC website. He had said that certain data for the preparation of Annual LGBR 2012-13 was awaited from some of the utilities and therefore requested the concerned constituents to submit this data immediately.

c) In the 18th SRPC meeting, it had been decided to obtain coal and gas supply position from the states for taking up the matter with CEA. The states had been requested to send the gas supply position to SRPC Secretariat for further needful. OCC noted in the previous meetings that the present gas availability of Gas Stations of TANGEDCO had varied between 75 % and 100 %.

d) Ministry of Power had approved Annual Generation Targets for the year 2012-13. All the constituents had been requested to make all efforts to achieve the targets as set for their organizations. The details had already been circulated in this regard.

3.18.2 In the Meeting it was noted that CEA had uploaded region-wise final

consolidated generation figures for the year 2012-2013. MS i/c stated that the

Members could deliberate on the pros and cons of deferring the maintenances

schedules. NTPC said that since the units were scheduled for planned

maintenance once in two years, the same could not be postponed. KPTCL

opined that considering the health of the generating units maintenance may


17

have to be carried out as per the schedule. Kerala also said that maintenance

could not be postponed. Andhra Pradesh stated that in view of deficit rain fall in

the region, rescheduling of maintenance of units could be considered. SRLDC

opined that schedules may have to be adhered to and not be postponed. MS i/c

informed that a special TCC, Meeting that had been proposed to be convened to

discuss issues due to delayed South West monsoon, could decide on the further

course of action in this regard. It was therefore agreed that this matter would be

deliberated and finalized in the Special TCC Meeting to be held shortly.

3.19 Technical minimum of NTPC Simhadri unit-3


a) In the 71st OCC meeting, APTRANSCO had submitted an Agenda item regarding methodology for technical minimum of Simhadri II unit. It was stated by AP that while the technical minimum of Simhadri II unit was furnished as 370 MW, the same was given as 329 MW in the case of Simhadri I units. During discussions, it was informed by NTPC that since Simhadri II unit was facing vibration problems at levels below 370 MW, the manufacturer had advised NTPC not to operate the unit below that level. NTPC also sought an outage for this unit from 20th to 29th June 2012 (10 days). They informed that PG test is to be carried out along with Boiler inspection and LP Generator Alignment works by M/s BHEL After discussions, it was urged by OCC that NTPC may arrange remedial measures to address the vibration problems of the unit during this outage period, so that the technical minimum of this unit can also be 329 MW.

b) In the 72nd OCC meeting, SRLDC pointed out that the machine (i.e. Generator) had not been serving the required functionality with regard to technical minimum. MS i/c noted that outage of the unit scheduled in June 2012 had been approved by OCC with the understanding that by addressing the vibration problem of the generator, the issue of technical minimum would also get resolved.

3.19.2 In the Meeting, it was noted that this unit was under shutdown since 19th June

2012 for maintenance works. The vibration problem affecting technical minimum

capability was expected to be attended during the shutdown period.

4. Low Frequency Grid Operation

4.1 Low frequency operation in the last month

MS i/c, SRPC said that the frequency of operation of the Southern Regional Grid

was less than 49.5 Hz for about 7.83 % of the time during June-2012. Mutual

support / cooperation was the need of the hour to operate the grid in a safe and


18

secure manner. He said that concerted efforts were required by the constituents to

operate the grid within IEGC parameters. SRLDC also stressed on suitable demand

side management by the constituents.

4.2 Grid code violation messages 4.2.1 Details of caution/violation ABC messages issued by SRLDC to the constituents

during the month of June-2012 are given at Annexure - XI.

4.2.2 SRLDC said that 12% violation messages of Over Drawal / Under Injection while

frequency was below 49.7 Hz over a time block were on the higher side as given

below: Number of 12% violation messages

Regional Entity June 2012 July 2012

(Up to 09th

)

Andhra Pradesh 413 160

Karnataka 112 42

Kerala 380 153

Tamil Nadu 154 21

Puducherry 3 0

LANCO 59 11

Simhapuri 298 1

Total 1419 390

SRLDC added that the States needed to put more efforts to curtail the instances

of overdrawals. As informed in earlier meetings, the details in this regard were

being regularly communicated to Hon’ble CERC.

4.2.3 In the 72nd OCC meeting, TN had pointed out that in the SCADA system,

Somanahalli Bus-I and Bus-II frequencies were not matching. TN had also

wanted to know the basis for issue of messages by SRLDC. They had stated

that messages based on a single instantaneous value may not reflect the grid

behavior properly. It was noted that Ramagundam frequency was being

considered for all cases. MS i/c had suggested that in the next OCC meeting,

SRLDC could give a presentation on the methodology being followed for

issuance of messages and clarify the issues.


19

4.2.4 In the meeting, SRLDC presented the Methodology adopted in issue of caution/

violation Messages (A, B, C, D, and O) in the form of a flow-chart. The details

are furnished in Annexure - XII.

4.2.5 With regard to 12% violation messages, KPTCL opined that since the system

operator would be compelled to use more hydro resources, thus depleting the

reservoir levels even further in order to avoid receipt of Type ‘D’ messages from

SRDLC, these messages could be considered to be avoided. However, SRLDC

stated that these messages were being issued as per Regulations and for

improved system operation.

4.3 Measures by constituents to improve the frequency

4.3.1 APTRANSCO informed that even with purchases and resource management,

the State had to face demand & energy shortages. Load shedding upto 3101

MW amounting to about 973 MU had been carried out during June-2012. Details

of Load relief imposed during the month of June-2012 are given at Annexure -

XIII. In this regard, letter dated 14th June 2012 from Director (GO),

APTRANSCO addressed to the DISCOMS on limiting their drawal to schedules

only is enclosed as Annexure - XIV.

4.3.2 KPTCL informed that load shedding in the State upto 1575 MW amounting to

about 568 MU for the month had been carried out. Strict grid discipline was

being adhered and nil messages had been issued to them during June-2012.

4.3.3 KSEB informed that with purchases they were able to maintain load generation

balance in their system. Need based load shedding up to 150 MW amounting to

about 16 MU had been carried out during June-2012. KSEB informed that

consumption above 90% of base average consumption during 2011-12 would be

charged at the rate of Rs.10/Unit from 26.04.2012 except for domestic. In

respect of domestic consumption above 300 units per month, would be charged

at the rate Rs. 10/Unit. In this regard, copy of letter dated 27th June 2012 is

enclosed as Annexure - XV. Measures taken by KSEB to maintain grid

discipline have been mentioned in this letter. These include cyclic load

restrictions and switching off of identified radial feeders as directed by SRLDC.


20

4.3.4 TANTRANSCO said that load shedding up to 3360 MW amounting to about 952

MU was carried out during the month. They briefed about the load restriction

measures in their system for June-2012 (implemented from 2nd) which is given

below:

40% in respect of HT Industrial and Commercial consumers

1 hour Load Shedding for Chennai (between 0800 to 1800 hrs.)

4 hour Load Shedding for urban and rural Areas (between 0600 to 1800 hrs.)

Agriculture was being fed 6 hours of three phase supply in day time and 3 hours of three phase supply in night time.

4.3.5 It was also noted that the second follow up meeting among TN, SRLDC & SRPC

Secretariat was held at Bangalore on 28th September 2010 in line with the

directions of CERC Adj No: 6/2009 (dated 27th April 2010). MS I/c, SRPC had

requested TANTRANSCO to furnish the progress regularly as decided in the

Meeting so that it could be communicated to the Hon’ble Commission. Pre-

approved contingency plan to take care of intermittency of wind was still awaited.

4.4 Arranging of interruptible loads in four groups

4.4.1 In the earlier OCC meetings, it was noted that as per IEGC, to maintain the

frequency within stipulated band and also to ensure network security, the

interruptible loads were to be arranged in four groups of loads. This was for the

purpose of scheduled power cuts/load shedding, loads for unscheduled load

shedding, loads to be shed through UF relays, df/dt relays and loads to be shed

under any SPS Scheme. These loads were to be grouped in such a manner

that there was no overlapping between different groups of loads.

4.4.2 It was noted that Andhra Pradesh, Kerala & Tamil Nadu had completed this

exercise. Puducherry had furnished the details regarding grouping of

interruptible loads.

4.4.3 KPTCL informed that grouping of loads had been completed and the details

would be furnished shortly

4.4.4 MS I/c, SRPC informed that in last few SRPC/TCC meetings constituents had

been informed of the requirements in this regard. He requested Karnataka to

complete the exercise in its system and inform the same to

CERC/SRLDC/SRPC Secretariat.


21

4.5 Automatic Demand Management Schemes

4.5.1 Automatic Demand Management Scheme in line with clause 5.4.2 (d) of the

IEGC was to be provided by all the constituents by 01.01.2011.

4.5.2 It was noted that Andhra Pradesh, Kerala & Tamil Nadu had implemented the

scheme. Puducherry had also furnished the details.

4.5.3 KPTCL had informed that had taken all measures to stick to its share during low

frequency conditions and to overdraw during high frequency by reducing hydro

generation to the maximum extent for maintaining grid discipline as per IEGC

standards.

4.5.4 SRLDC & SRPC Secretariat requested KPTCL also to expedite the

implementation of the scheme in its system in line with IEGC provisions, since

the scheme had already been approved by SRPC and was mandated as per

IEGC.

4.5.5 It was also suggested that constituents could identify other Demand

Management Schemes other than Automatic Load Shedding Schemes.

4.5.6 In the meeting, SRLDC opined that since on some of the days, the frequency

was for more than 20% of time below 49.5Hz, it appeared that the scheme had

been not effective fully to take care of fall in frequency, though the constituents

had stated in their affidavits submitted to CERC that Automatic Demand Management scheme was ready in their system. SRLDC stressed that radial

feeders had to be identified for remote operation of automatic load shedding.

4.6 Automatic Load Disconnection Schemes for overdrawing constituents

4.6.1 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:

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


22

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

of load under crisis period has been identified. The same was ready for

operation and details would be intimated.

4.6.3 It was noted that the Automatic Load Disconnection Scheme was part of

Automatic Demand Management Scheme which had been discussed above. It

was noted that Puducherry had provided remote tripping facilities in the

identified feeders in order to provide emergency disconnection.

4.7 On Line Demand Estimation

In the earlier OCC meetings, it was noted that all the states were furnishing the 15

Minute requirements. The constituents were apprised that the forecasting tool

should take into account weather inputs as well.

4.8 OCC observations

Karnataka maintained grid discipline with NIL Type ‘B’ & ‘C’ messages during the month of June’12

Issuance of NIL type ‘C’ messages to AP, KAR, KEL, Pondy by SRLDC indicated that the respective constituents had taken action with in 20 minutes of the system frequency below 49.5Hz.

Some of the days SR grid had operated with frequency below 49.5Hz for more than 20% of the time which had touched as high as 27% on 1st June’12 that reflects the corrective actions taken were momentarily, with out realistic matching of the Load Generation balance of the constituent, probably to avoid type ‘C’ messages.

The instances of maximum frequency during June’12 is due to sudden load change over that reflects inconsistent co-ordination between TN and AP

The instances of Minimum frequency during June’12 is during tripping of Major grid elements that reflects significantly inadequate response of RGMO / FGMO in Southern Region

With depleting reservoir position and poor monsoon, proper planning and co-ordination of all the constituents are very much essential to be conducted

On 17th June 2012 for about 12% of time and on 19th for about 9% of time SR Grid operated with a frequency above 50.2 Hz.


23

Ensuring adequate capacitor Banks at LT side and also introduction of

under voltage relays are essential for ensuring system security.

5. Grid Operation

Different aspects of grid operation were reviewed and the following grid events were

noted. Grid operation data for June-2012 is enclosed as Appendix - A.

5.1 Grid events 5.1.1 Frequency profile during June -2012:

a) Frequency remained within IEGC range (49.5 - 50.2 Hz):

i) During June -2012: 91.03% of time

ii) Previous month (May-2012): 94.01% of time

iii) Same month last year (June -2011): 95.97% of time

b) Frequency remained below 49.5 Hz for 7.83% of time c) Frequency remained above 50.2 Hz for 1.14% of time

d) Average frequency was 49.68 Hz.

5.1.2 Activities: a) Wind generation in SR reached 104 MU on 24.06.2012.

b) 25% energy (60 MU) of TN was met through wind on max demand day - 26.06.2012.

c) Simhapuri Energy Ltd. Unit II of 150 MW (Andhra Pradesh) achieved full load on 02.07.2012.

d) Tamil Nadu met a Maximum Demand of 11283 MW on 26th June 2012 which is the maximum till date.

e) Tamil Nadu met a Maximum Day consumption of 243.88 MU on 20th June 2012 which is the maximum till date

5.2 Generation capacity added

The following were the additions to Installed Capacity to SR Grid during the

month:

State Sector Type Station Capacity (MW)

Date of commissioning

Tamil Nadu Private Wind

Mill Wind Mill 31.15 June 2012

Karnataka State Wind Mill

Belakawadi 5.00 25th June 2012

Karnataka Private Wind Mill

Wind Mill 116.50 June 2012


24

5.3 Transmission lines added

Transmission lines added in SR system during the month: NIL

5.4 Substations added

Sub-stations were commissioned during the month: NIL

Sub-stations augmented during the month: NIL

5.5 Maximum demand met & Average daily consumption 5.5.1 The Table below furnishes the details of actual Maximum Demand met (MW) &

Average Energy Consumption per day (MU) in respect of the SR constituents for

June-2012 vis-à-vis July-2011. The maximum daily consumption by the

respective constituents during June-2012 is also included.

System

State

Actual Maximum Demand (MW)

Average Consumption/day (MU)

Max. Daily Consumption during June 2012 (MU)

June 2012

June 2011

%-age variation

June 2012

June 2011

%-age variation

a b c=(a-b)/b d e f=(d-e)/e Andhra Pradesh 11279 10503 7.39 228.83 225.47 1.49 254.44

Karnataka 8249 6989 18.03 163.98 132.54 23.72 183.28

Kerala 3182 2874 10.72 54.58 48.15 13.34 61.59

Tamil Nadu 11283 10713 5.32 232.02 224.19 3.49 243.88

Puducherry 320 306 4.60 6.59 6.24 5.98 6.61

Southern Region 32110 30152 6.49 686.01 636.59 7.76 710.26

5.5.2 It could be seen from above that the Peak Demand of all the states in June-

2012 recorded positive percentage variation (5 to 18%) compared to June-2011

figures. Southern Region as a whole had met a maximum demand of 32,110

MW in June-2012, which was 1958 MW more than last year’s figure of 30,152

MW. In respect of average daily energy consumption also all the constituents

had registered a positive percentage variation (2 to 24%). Both Actual Maximum

Demand and Average daily energy consumption of Southern Region were about

7% more than during last year

5.6 Load duration curve & Daily consumption patterns It was observed from the SR Load Duration Curve for June-2012 (Annexure - XVI)

that the maximum demand was in between May-2012 & June-2011 values for about


25

90% of time. State-wise daily consumption patterns were also presented

(Annexure – XVII).

5.7 Hydel Availability

5.7.1 The energy availability in major hydel reservoirs at the end of June-2012 vis-à-

vis that for June-2011 was reviewed, which is given below:

(Figures in MU)

System State

Energy at FRL Storage as on Inflows in June 2012

30.06.2012 30.06.2011 Anticipated Actual ANDHRA PRADESH

Jalaput 495 135 369 27 20 (827.07)* (834.34*) Srisailam 269.8* 0 15 23 1 (MDDL:243.8m) (243.69)* (244.97)* Nagarjunasagar 179.8* 10.169 596 (MDDL:149.3m)

(155.72)* 169.9

KARNATAKA Linganamakki 4547 471 1162 565 185 Supa 3152 324 849 213 63 KERALA Idukki 2190 254 819 281 150 Kakki 916 55 301 149 52 Total 4131 469 1499 740 339TAMIL NADU Nilgiris 1504 183 463 431 107 Total (excluding Mettur)

2183 334 810 635 157

* Level in meters.

5.7.2 SRLDC stated that energy storage in the hydro reservoirs showed around 68%

deficit (3107 MU) as on 30th June-2012 compared to the same day last year and

about 53% (1648 MU) deficit in monthly (i.e. June) average compared to last 10

years’ corresponding monthly average. They stressed on appropriate R&C

measures during the coming months on account of the poorer hydro position

resulting from inadequate monsoon.

5.7.3 It was requested to continue the optimum utilisation of hydro, keeping in view the

energy storage position vis-à-vis management of demand/energy requirements

from the overall view of maintaining system parameters within IEGC limits and to

optimize the load generation balance.


26

5.8 System Frequency


a) The recommendations finalized in the 60th OCC are reproduced for implementation please:

Karnataka & Tamil Nadu to finish their changeover during 1730 – 1800 hrs with proper staggering (evenly spread over).

Andhra Pradesh to finish their changeover during 1800-1830 hrs with proper staggering (evenly spread over).

Andhra Pradesh to decrease it’s under drawal during changeover period.

Improved coordination with Discoms required.

Each state to balance its load removal with matching generation reduction.

No loads should be taken out at frequency > 50.0 Hz.

Loads removal should preferably be frequency dependent rather than time dependent.

SLDCs may consider tripping of some of the feeders from their control room using SCADA.

States could plan automation of load changeover with reference to frequency.

All the units should participate in RGMO which would help moderate the impact of the changeover.

Proper training and awareness should be imparted to the officials handling the substations.

Generating stations including ISG stations should not inject excess power into the grid above 50.2 Hz.

It was noted that there were other frequency excursions during other changeovers and the recommendations needed to be implemented in respect of those periods also. All the constituents were requested to adhere to above recommendations to avoid excursion in frequency during changeover.

b) KPTCL had said that as informed earlier they had taken all precautionary measures by backing down hydro generation to the maximum possible extent without under drawing from CGS during high frequency conditions. They were monitoring the situation on a daily basis and the change over time had been staggered by 15-20 minutes either by postponing & proponing. However at times due to line loading issues, Karnataka was forced to under draw.

c) A Special Meeting to discuss issues relating to load changeover had been held on 8th March 2012 (A.N) after conclusion of the 69th OCC Meeting. SRPC had presented Summary showing frequency excursions above 50 Hz in the last 5 months with time and number of occasions. After discussions, it was decided that AP would postpone the load changeover


27

by 10 minutes from the existing schedule both during the morning and evening peak hours on 12th and 13th March 2012. The results of this exercise would be deliberated in the 70th OCC.

d) As detailed by MS i/c in the 70th OCC meeting, AP had shifted timing of load changeover on 13th March and submitted the data to SRLDC. SRLDC had stated that on that particular day, the frequency excursion was not noticed. They had also hoped that with better coordination among the states, the sharp rise in frequency could be contained. MS i/c had complimented Andhra Pradesh for the cooperation extended and efforts taken in load staggering. TN had informed the Members that every hour load shedding was being done in the state to overcome the severe power shortage and said that they would be ready for similar load changeover exercise by LDCs with a gap of five minutes amongst them on 20th and 21st April, 2012. The results of this exercise would be deliberated in the 71st OCC.

e) In the 71st OCC meeting, it was noted that Tamil Nadu had carried out load changeover timings on 20th and 21st April, 2012 and the analysis would be submitted in the next OCC meeting.

f) In the 72nd OCC meeting Tamil Nadu had submitted the details in soft copy to SRPC as well as to SRLDC. It was agreed that the data would be analyzed in 73rd OCC meeting to be held on 11th July 2012.

g) In the meeting SRLDC informed that they would analyze the data furnished by TANTRANSCO and present the observations in the next OCC meeting. It was also agreed that the matter would be deliberated in greater length in the 74th OCC Meeting.

5.8.2 Frequency within IEGC band: 49.5 – 50.2 Hz

a) It was noted that the SR frequency during the month of June-2012 was within IEGC range for about 91.03% of the time, as compared to 95.97% of IEGC range during June-2011.

b) OCC observed that grid operation below 49.5 Hz and above 50.2 Hz should have been avoided since it violated the provisions of IEGC and also caused threat to grid security. Operational control needed to be streamlined so that uneconomic operation of the grid above 50.2 Hz is avoided.

5.8.3 Frequency below 49.5 Hz: It was also noted that the frequency of grid operation was in the lower range of

IEGC and had operated below 49.5 Hz for 7.83 % of the time during the month

of June-2012. It was also noted that the frequency on some of the days was

less than 49.5 Hz for more than 5% of the time duration as shown below:


28

Date

(%) Percentage of time of frequency Less than 48.5 Hz

48.5 Hz & < 49.0 Hz

49.0 Hz & < 49.2 Hz

Less than 49.5 Hz

1/6/2012 0 0 1.32 27.22 2/6/2012 0 0 0.76 14.23 3/6/2012 0 0 0.28 5.77 4/6/2012 0 0 0 7.99 5/6/2012 0 0 0 7.71 7/6/2012 0 0 0 6.81 8/6/2012 0 0 0 6.88 10/6/2012 0 0 0 11.39 11/6/2012 0 0 0.14 12.57 12/6/2012 0 0 0.28 20.63 13-06-2012 0 0 0.21 18.13 14-06-2012 0 0.42 0.56 16.74 15-06-2012 0 0 0 7.5 22-06-2012 0 0 0 6.18 23-06-2012 0 0 0 8.82 24-06-2012 0 0 0 5.28 26-06-2012 0 0 0.21 6.95 29-06-2012 0 0 0 6.67

5.8.4 Frequency above 50.0 Hz:

It was also noted that the Regional Grid had operated above 50.2 Hz for 1.14%

of the time, during the month. It was also noted that the frequency on some of

the days was more than 50.0 Hz for some 5% and above period of time as given

below:

Date % of time of frequency:

50.0 Hz & < 50.2 Hz More than 50.2 Hz

17‐06‐2012 27.43 12.43 18‐06‐2012 25.07 5.28 19‐06‐2012 22.43 9.24 20‐06‐2012 9.79 2.5

TN had informed that load shedding timings were adjusted by three LDCs for

controlling frequency excursion.

5.8.5 Frequency histogram & Frequency duration curve:

SRLDC said that RGMO/ FGMO (characteristics of RGMO with manual

intervention) implementation in all the units would also help in easing the


29

situation. SRLDC also presented the Frequency Histogram & Frequency

Duration Curve (Annexure - XVIII) for June-2012. They said that the regional

entities were being requested to furnish details to SRLDC to analyse and

ascertain effectiveness of RGMO/FGMO participation of individual major thermal

units in the region with respect to specific instances.

5.9 Under Frequency Relay


a) It had been emphasized that the UFRs were meant for protection of the grid. As stressed earlier, set points should not be changed in any manner. It had also been stressed at higher levels that the UF Relays be made fully effective by all the utilities so as to give the designated relief at specified frequency levels.

b) Tripping details like name of the feeder, load affected, date and time of the tripping, frequency at the time of tripping and restoration time needed to be furnished to SRLDC/SRPC regularly and in a timely manner. Constituents agreed to furnish the details in a timely manner. It was also noted that the IEGC stipulates that SLDC shall furnish a monthly report of UFR & df/dt relay operation to the RPC.

c) MS i/c, SRPC had said that reasons for tripping at undesired settings needed to be examined. Corrective action such as calibration is required to be taken to avoid such incidents in future. He also informed that as part of the annual exercise, the quantum of UF relays had been reviewed and had been circulated.

d) In the 70th OCC meeting, TANTRANSCO had informed that in the recent grid disturbance that had occurred on 3rd April 2012, owing to low frequency a load relief of 650 MW was realized from TN. Similarly during the tripping of Talcher – Kolar Pole II on 29th February 2012, no other state except TN had reported any relief. They said that any sudden loss of generation should be shared by all the constituents and not burden any constituent. SRLDC was requested to ascertain the UF relay operation in other states also during this disturbance.

e) As discussed in the 70th OCC meeting, for the year 2012 -13, additional Load relief (303MW) was to be implemented by constituents through AUFR- Constituents had been requested to intimate the progress in this regard in the next OCC Meeting.

5.9.2 Puducherry had furnished details of the identified feeders (as per SRPC

directions) and the same is furnished at Annexure - XIX. Karnataka, Kerala,

Tamil Nadu and Puducherry had reported UFR trippings during June-2012.


30

5.10 df/dt Protection System

5.10.1 Karnataka, Kerala & Tamil Nadu had reported ‘nil’ trippings during the month of

June-2012.

5.10.2 It was noted that an additional df/dt quantum(2000 MW) was to be implemented

by the constituents as reviewed and accepted in the Protection Sub Committee

meeting held in March 2012. Puducherry informed that the feeders had been

identified and action had been initiated for procurement of the tripping relays and

installation is expected to be completed soon. The other constituents were

requested to appraise the forum about the progress of implementation in the

next OCC Meeting.

5.11 Inter-trip Scheme

5.11.1 HVDC Talcher – Kolar link

a) SRLDC had suggested modification of SPS for operation of HVDC Talcher-Kolar bipole at 2500 MW level and also for load relief during the instances of tripping of all units at Talcher Stage-II making zero flow in HVDC Talcher-Kolar bipole.

b) It was noted that in the recent Protection Committee meeting, PGCIL had informed that that the works on inter-trip signal III would be completed by end December 2011. In the 67th OCC meeting, it was informed that the third signal may be available by middle February 2012.

5.11.2 The tripping details as furnished by the constituents are at Annexure - XX.

6. Anticipated Availability and Consumption for the months of July-2012 & August-2012 6.1 OCC noted the information regarding anticipated availability & requirement for the

months of July and August 2012 as furnished by the Constituents and the same is furnished at Annexure - XXI.

6.2 All the constituents agreed to initiate requisite measures to maintain appropriate

load generation balance in their systems, and adhere to the IEGC provisions.

6.3 Review of the availability during June-2012

The Table below gives the anticipated availability as furnished in the 72nd OCC

against the actual availability for the month of June-2012:


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(Figures in MU)

State Anticipated

availability as given in 72nd OCC

Actual availability (ex-bus)

Deviation

a b c = b - a Andhra Pradesh 211.93 229.69 17.76 Karnataka 152.23 163.98 11.75 Kerala 44.01 54.58 10.57 Tamil Nadu 229.25 232.02 2.77

6.4 It was noted that the average load shedding per day in the states were: Andhra

Pradesh – 32 MU, Karnataka - 19 MU, Kerala – 0.5 MU, and Tamil Nadu – 32 MU.

6.5 SRLDC stated that the loss of generation due to coal shortage/technical

problems was to be furnished by 10:00 hrs for onward transmission to NLDC.

7. Restricted Governor Mode of Operation (RGMO)

7.1 The following was noted in the earlier Meetings:

a) RGMO operation was highly critical during load changeover. As informed earlier, NLDC had been submitting the status report of RGMO in various regions to Hon’ble CERC on a monthly basis. He pointed out that as per CERC Order on Petition No.237/2010, the units were required to be put on FGMO, in case RGMO operation was not possible. Either RGMO or FGMO should be in place for all the units as mandated under IEGC. If under FGMO, with manual intervention the units should be operated for the desired characteristics of RGMO.

b) KPCL had said that most of the thermal stations were using coal which was not as per the designed calorific value. The mills were therefore overloaded and there was no further provision for additional generation. DGM, SRLDC enquired that if that was the case, why the units were not reducing the generation when the frequency was on the upward trend.

c) MS i/c, SRPC had said that maximum number of units needed to be put in RGMO in the interest of the security of the grid. For any constraints for implementation of RGMO on particular units, exemption from CERC could be obtained.

7.2 SRLDC pointed out that there was inadequate response from thermal generating

stations. Mostly hydro generating units are responded (which are under FGMO). On

all instances Idukki, Varahi, Nagjheri, Lower Sileru, Sharavathi, Kundah I, II & III

were responding for immediate increase and decrease. SRLDC had been seeking

unit-wise MW generation/frequency/throttle valve plot details in specific instances to

analyze and ascertain the effectiveness of RGMO/FGMO participation of major

thermal units.


32

7.3 SRLDC presented the RGMO Analysis Summary (details in Annexure - XXII).

8. Voltage Profile

8.1 High Voltage

8.1.1 In the 68th OCC meeting the following was noted:

SRLDC had expressed concern over high voltage conditions at Vijayawada and

Gajuwaka though both these nodes are near generating plants. He stressed the

need for reactive power absorption within the limits of machine capability curve

for keeping the voltages under check. He further disclosed that a mock-exercise

was proposed to be conducted in the month of March 2012. At this juncture, MS

I/c had suggested that a study could also be conducted to ascertain bus

sensitivity to reactive power absorption. MS I/c had also suggested that

APTRANSCO, APGENCO and SRLDC together could carry out the studies and

the report of this study could be presented to the OCC forum. TN had informed

that Gas stations in Valathur area were not absorbing adequate reactive power

and citing technical constraints for the plant.

8.1.2 It was noted that Nagarjunsagar, Vijayawada, Gazuwaka and Gooty were facing

high voltage situation. There were 87 trippings due to over voltage of the 400 kV

lines during the month. It was noted that Jeypore - Gazuwaka I, Vijayawada-

Vemagiri I & III, Thirunelveli-Kudankulam I, III & IV, Kalpakka-Vemagiri I & II,

Talaguppa-Nelamangala and Vijayawada – Simhadri lines were kept open for

more than 3 days due to over voltages.

8.1.3 In the meeting, SRLDC presented the high voltage graph for the nodes at Gooty,

Hiriyur, Hyderabad, Kurnool, Nagarjunsagar, Srisailam, Vijayawada, for 10th to

20th and 30th June-2012 when high voltage conditions had prevailed (Annexure

- XXIII). It was noted that reactive power absorption of Simhadri-II had shown

some improvement. SRLDC desired to know the action plan of AP in bringing

back Bus Reactor nos 2 & 3 at Kalpakka.

8.1.4 SRLDC stated that simultaneous critically High Voltages at some locations and

low voltages at some locations of the grid posed the threat of power swing.

8.1.5 In the meeting, NTPC Simhadri suggested that to contain the voltage in the

area Kalpakka bus reactor had to be brought into service. It also opined that


33

lightly loaded lines in the area could be kept open. SRLDC stated that the

operators would take a call on opening of lines after exploring all other avenues.

Opening of line led to depletion and consequent threat to system security. MS i/c

suggested that provisions in the Operating Procedures already existed which

could be implemented in real time operation. Srisailam units would also need to

run in synchronous mode of operation to absorb the MVAR.

8.2 Bus/Line Reactors to be commissioned

The updated information on schedule of commissioning of reactors as originally

agreed in the Standing Committee on Power System Planning of Southern Region is

furnished at Annexure - XXIV. KPTCL had informed that work of design, supply,

erection and commissioning of new 63 MVAR bus reactors at Guttur, Talguppa,

Nelamangala and Hoody had been awarded to M/s BHEL on turnkey basis and

works were under progress. In the meeting, DGM, SRLDC informed the status of

ongoing Bus/Line reactors installation based on the inputs received.

8.3 Re-commissioning of Reactor at Guttur/other Reactors

The issue regarding 50 MVAR line reactors on 400 kV Guttur-Birenahalli – I at

Guttur S/S and 400 kV Nelamangala-Hiriyur – II at Nelamangala was discussed in

the TCC meeting held on 29th April 2011 and number of OCC Meetings. KPTCL

had been requested to take up this issue with Standing Committee on Power

System Planning. Subsequently, CEE (LD), KPTCL had taken up the issue with

CEE (P&C), KPTCL vide letter dated 13th June 2011. CEE (LD), KPTCL informed

that reply dated 23rd July 2011had been received from CEE (P&C), KPTCL. In view

of the contents of the letter, the issue could be further deliberated at TCC level. In

earlier forums it had been pointed out to KPTCL to take up the issue with Standing

Committee.

8.4 Low voltage


a) In the 59th OCC meeting, OCC had suggested that KPTCL & TANTRANSCO may examine the possibility of provision of under voltage relays in some of the low voltage nodes in their control areas. In the 61st OCC Meeting Regulation 4.6.1 was referred as given below:


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4.6.1 Reactive Power Compensation

a) Reactive power compensation and/or other facilities, shall be provided by STUs, and Users connected to ISTS as far as possible in the low voltage systems close to the load points thereby avoiding the need for exchange of Reactive Power to/from ISTS and to maintain ISTS voltage within the specified range.

Regulation 5.2 (t) was also referred as given below: 5.2 (t) All Users, CTU & STU shall provide adequate voltage

control measures through relay as finalized by RPC, to prevent voltage collapse and shall ensure its effective application to prevent voltage collapse/cascade tripping.

It had been felt that the utilities could examine provision of under voltage relays as mandated in IEGC Regulations to control low voltages at the following 400 kV nodes: Sriperumbudur, Alamathy, Chittoor, Nellore, Mysore, Somanahalli, Kalavindapattu, Trichur & Hosur. Subsequently, the issue had also been taken up by Member Secretary I/c, SRPC with the TCC Members of State utilities vide letter dated 11th July 2011.

b) KPTCL had informed that all CEE Transmission Zones had instructed concerned Executive Engineers of TL & SS Division under their jurisdiction to maintain all capacitors in healthy condition and connected to the grid positively during low voltage condition.

c) In the 68th OCC meeting, concern had been expressed about low voltage situation in Chennai area. TN informed that capacitor bank installation in Chennai area was under execution and was expected to be ready by March-2012. DGM, SRLDC said that while high voltage conditions were prevalent in S1 area, low voltage conditions were prevalent in S2 area. MS I/c said that during the current financial year to date there had been no addition to capacitor bank installation in the region. He urged the constituents to undertake capacitor installation programme to improve the voltage profile. KPTCL informed that laying of 220 kV cables in Bangalore had resulted in some improvement of the voltage.

d) In the 69th OCC meeting, Concerns were raised by SRLDC over increasing demand in Karnataka and also low voltage situation (at some times below 380 kV) in Bangalore. Karnataka attributed low voltage problem on certain days due to non-availability of 600 MW UPCL unit. TN informed that capacitor bank works were likely to be completed by April-2012. It also opined that system studies at 400 kV for compensation may not pin point the problems in distribution network and said that exclusive studies were required at 11 and 33 kV level to address the issue.

e) In the 72nd OCC meeting:

i) SRLDC stated that low voltage conditions had prevailed in various substations in the region during June-2012: Tamil Nadu (Kalivandapattu, Sriperumbudur, Almatty), Karnataka (Somanahalli, Hoody, Nelamangala, Mysore), Kerala (Trissur).


35

The voltage in Chennai area had gone to a level of 366 kV. On many days it had remained below 380kV level for more than 50% of the time. (Max.87% of the time). Despite injection of MEPL & SEPL, the ATC of S1-S2 could not be enhanced due to continuous low voltage profile around Chennai. In case the situation continued, SRLDC may be constrained to reduce the ATC of S1 – S2 to safeguard system security. They added that ensuring adequate Capacitor Banks at LT side and also introduction of under voltage relays were essential for ensuring system security. SRLDC stated that necessary action was therefore highly essential to improve the voltage parameters in the above nodes.

ii) On the presence of continued low voltage at Kalivandapattu (354 kV) and high voltage at Vijayawada (426 kV), SRLDC cautioned that such conditions may lead to power swing phenomenon between two control areas. It was opined that low voltage around Chennai area could be due to the highly reactive load of large number of A/C units.TN informed that one unit of ETPS may be run as synchronous condenser for supplying capacitive-reactive power to the grid and improving the low voltage conditions. Hon’ble TNERC is being approached to stipulate a provision that all domestic and commercial single and three phase consumers with 1.0 Tonne Air Conditioner and above should have the required capacity of capacitor for VAR compensation so as to minimize the low voltage problem. Purchase order had been released for 70 sets of 2.4 MVAR to be erected throughout the state. 35 sets of 2.4 MVAR 11 kV capacitor banks had been diverted to Chennai. 5 sets of 2.4 MVAR capacitor banks had been commissioned in 4 substations. TN’s long term measures taken for addressing reactive power compensation in the grid for improving the low voltage were appreciated. Regarding measures being taken in the short term, TN informed that load shedding was also being carried out as a measure.

8.4.2 In the meeting it was noticed that continuous low voltage was observed at

Kalivanthappattu, Sriperumbudur, Alamathy, Trivandrum & Trichur. The voltage

in Chennai area had gone to a level of 355 kV on 02.06.2012. Persistent low

voltage profile was observed around Chennai area which caused severe threat

to grid security. In this regard, copy of letter dated 22nd June 2012 from

TANTRANSCO is enclosed as Annexure - XXV. It had been reiterated by

TANTRANSCO that it was reviewing the low voltage position continuously and

taking all measures to restrict the MVAR drawal from the Grid. The measures

taken in this regard had also been furnished in the letter.


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8.5 Absorption / Injection of VARs by Generators


a) Hon’ble CERC Order dated 23.12.2009 merited attention in this regard. It was stated in the Order that all agencies need to provide required reactive compensation avoiding the need for exchange of reactive power to/from ISTS and maintain ISTS voltage within specific range.

b) In the 68th OCC meeting, MS I/c, SRPC had requested the concerned SLDCs to take up the issues with the generators to respond as per grid requirements within the margins available to them.

c) In the 69th OCC meeting SRLDC had informed that it planned to conduct Mock Exercise for analysis of MVAR absorption/injection capability of individual generating units of ISGS in SR on sample basis. The units would be subjected to for measuring MVAR absorption at different MW levels. The Mock Exercise was planned in the last week of March 2012. The Members expressed difficulty in conducting such Mock Exercise during the regional peak months of March and April. It was therefore decided to reschedule this exercise after June-2012.

d) In the 69th OCC meeting, SRLDC had stated that despite raising this issue in the last few OCC meetings not much progress was observed. The reasons for non-absorption MVARs by generating units was not being informed or known. Many of the generating units had not fully utilized their capabilities of MVAR absorption for maintaining the voltage at around 400 KV. Further, it was also pointed out that quite some time ago, NTPC Ramagundam had been requested to change the taps and yet no information on its implementation was received. MS i/c suggested a special meeting on MVAR absorption by Generating units with generators, IPPs and constituents be held. It was agreed to conduct this meeting after conclusion of the 70th OCC meeting on 9th April-2012. It was also agreed that SRLDC would circulate some of the specific instances when the voltage profile was above IEGC range and adequate margin for MVAR absorption by major generating units was available.

e) A Special Meeting on MVAR absorption had been held immediately after the conclusion of 70th OCC meeting with participation from Generating Companies. SRLDC had circulated some of the specific instances when the voltage profile was above IEGC specified range and adequate margin for MVAR absorption by major generating units was available. NTPC pointed out that power factor was also to be considered while deciding the MVAR absorption limits of the generator. It was expressed by the generators that various reasons such as heating of the windings, and stability factor were limiting MVAR absorption by the generating units. Subsequently SRPC had addressed a letter to the generators requesting them to furnish the data also containing the limiting factors, which would be discussed after conclusion of the 71st OCC Meeting


37

f) The following was noted in the 71st OCC Meeting:

i) SRLDC said that the performance of generators was being monitored by SRLDC. MVAR absorption / injection of generating stations/units located close to high voltage nodes for 15th April 2012 and 29th April 2012 were presented .Nearly all the units were not absorbing VARs up to the desired levels. In the study, only 30% MVAR capacity had been considered which could be around 40% as per the capability curves. The chart showed that Ramagundam STPS (Unit 5 & 7), and Kakatiya could absorb more MVAR.

ii) SRLDC, presented analysis of 5-minute data of the Simhadri unit - 500 MW (588 MVA), 21 kV, 16.166 kA, 0.85 pf. Based on the generators feedback, It was noted that old DCS could only give hourly data whereas new DCS would give 5-minute / 1-Minute data of the generator parameters.

iii) Based on the analysis, following were noted and agreed by NTPC officials:

Maximum Permissible Operating range MVAR of Simhadri U#3 as per capability curve at 500MW is 300 MVAR (Injection) TO 180 MVAR(Absorption) & confirmed from the Manufacturer by SRLDC.

Simhadri Maximum absorption was 66 MVAR when the voltage was high during the observation period and there was further scope for absorption.

SRLDC suggested that GT taps / UAT taps could be changed to absorb more reactive power within the capability curve of the generator while transferring maximum power at 21 kV.

MS I/c suggested that the GT taps could be changed during the shutdown of the unit in June-2012.

NTPC officials affirmatively said that they would change the taps of GT first then that of UAT subsequently. Until that point of time they would try to maximize their MVAR absorption during high voltage.

iv) MS I/c had stressed that the data analysis had to be focused on a specific instance of time where MVAR absorption could have been more with parameters within limits without endangering the system security. SRLDC was requested to study the MVAR absorption for other units near high voltage zones during the Monsoon season by collecting the data from the generators and subsequently discussed in OCC.

8.5.2 In the 72nd OCC Meeting, SRLDC had said that a special meeting with regard to

MVAR absorption data pertaining to VTPS#7, RTPS, BTPS & Jindal Power for

a specific period was also requested similar to the one had with NTPC,

Simhadri MS I/c requested all the generators to please send the MVAR

absorption data for the period from 12th June to 18th June 2012 in soft copy to


38

SRLDC as well as to SRPC by 22nd June 2012. The matter would then

subsequently be discussed on the afternoon of 11th July 2012 after conclusion

of 73rd Meeting of OCC of SRPC at Bangalore.

8.6 Reactive power absorption meeting SRLDC pointed out that data were submitted by constituents with varying time

frame. The summary of the Analysis is as follows:

• Simhadri unit-3 o Absorbed upto 126 MVAR

o Voltage was > 430 kV for > 45 minutes, the generator tripped.

o Tap was changed from 6 to 7 (399 kV).

• Kothagudem 500 MW o MVAR injection observed

o Tap is at 3 (420 kV) for purpose of synchronization at HV;

o Tap should go to 5 (400 kV) during next outage of the unit

• Vijayawada: VTPS- 7 o Upto 78.9 MVAR absorption

o Tap is at 3 (441 kV)

o Tap should be changed to 7 (399 kV) during next outage

o It was noted that from 1st August-2012, the unit would be under shutdown

• RTPS o Unit-4: Japanese make – Mitsubishi

o DCS of the units are of different types with different data format

o Data yet to be analysed

• GMR Vemagiri Gas turbines o Could absorb 100 MVAR

o 60 MVAR absorption was noticed

o 13 -14 MVAR injection was also noticed

o Tap position had to be changed for all the generators

o Machines are going out daily, so the taps needed to be changed before

31st July, 2012

• Kaiga Atomic Power station unit #3 & 4 o Unit#3:

Upto 26.34 MVAR absorption; can go up to 80 MVAR

Tap is at 3; it should be set at nominal 4 tap in the next shutdown


39

o Unit#4:

Upto 37. 4 MVAR absorption; can go up to 80 MVAR

Tap is at 3; it should be at nominal 4 tap in the next shutdown ( due

in Jan-2013)

• KPCL o Data from Bellary was required

8.7 Requirement of reactor at Vemagiri Complex

It was noted that the requirement of reactor at Vemagiri Complex was deliberated in

earlier Standing Committee Meetings and APTRANSCO was to take a call on this

issue. There had been no further developments communicated by APTRANSCO.

There were some issues with GTs in the Complex with secondary voltage as 420 kV

and the area was facing high voltage. SRLDC vide letter dated 12th June 2012

addressed to APTRANSCO had again requested that the commissioning of bus

reactor at Vemagiri needed to be expedited.

9. Installation of Shunt Capacitors

The progress of installation of HT shunt capacitors was reviewed and the details are

listed below:

(Figures in MVAR) Sl. No. Description APTRANSCO KPTCL KSEB TNEB Total

1. Total Installed as on 31.03.2012 6593.4 4622.12 995 3947.5 16158.016

2. Carryover of 2011-12 55 74.16 10 101 240.16

3. Capacitors installed during June- 2012 0 5.804 0 12 17.804

4. Total Cumulative installed for 2012 -13 0 5.804 0 19.2 25.004

10. Notified Power Cuts

MS i/c SRPC requested that details of Notified power cuts and load shedding be

segregated and informed to SRPC Secretariat/CEA in a timely manner by written

communication to appraise MoP/GoI appropriately.


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11. Other Issues

11.1 Crisis Management Plan/Black Start Procedures 11.1.1 The following was noted in the earlier meetings:

a) The format to furnish the information regarding Crisis Management Plan was furnished in the 44th OCC Minutes. The information is required to be sent to the following E-mail addresses:

i) [email protected] ii) [email protected] iii) [email protected]

b) In the 64th OCC meeting, MS i/c, SRPC had informed about the letter dated 27th September 2011 received from CEA wherein it was informed that the CMP was being monitored at the highest level. For this purpose, various utilities/organizations were required to submit Quarterly Reports through Regional Power Committee (RPCs) / National Load Despatch Centers (NLDC). The proforma for the report of mock drills indicating the scenario of mock drill situation, chronological order of events logged, observations on effectiveness of mock drill and recommendations/suggestions on the observations etc. had already been communicated. It was also indicated that CMP be made applicable to private players of power sector. Concern over only few utilities submitting the report had been expressed. RPCs had been requested to advise the utilities / constituents to submit the quarterly reports regularly.

c) SRLDC had informed that the requirement of synchronising facility at black start restoration critical substations had been discussed and followed up in various OCC/Protection Committee Meetings. KPTCL informed that all critical 220 KV substations are having synchronization facility except Hubli, this would be taken up in R & M works.

d) In the 71st OCC, SRLDC informed that Mock exercise for availing start-up power through A/C by-pass at HVDC Bhadrawathi was being planned. KPCL had been requested to furnish mock drill schedule for 2012.

e) In connection with mock exercise for AC by-pass at Bhadrawathi, it was opined that the exercise would need to be carried out when one of the units under outage was to be brought back. Further voltage related issues would also need to be addressed

11.1.2 AC By-pass mock drill at NTPC Ramagundam The following was noted in the meeting:

a) NTPC informed that unit-3 currently under outage would be brought back shortly and the unit-7 was likely to be under shutdown from 17th July-2012 onwards. NTPC expressed constraints for the mock drill exercise under the prevailing high voltage conditions .It opined that if the voltage was brought down below 410 kV by connecting some 132 kV loads at least for 1 or 2 hours then the exercise may be possible.


41

b) SRLDC stated that the proposed bus reactor anyway may not be able to control the voltage since it was at a different bus section. It informed that last time the exercise was without involving loads whereas for regulation purpose it could be carried out end to end with the provisions of split bus arrangement at intermediate buses. It stressed that the objective of conducting the exercise was to simulate any real-life emergency situation and practice the operations for restoring the supply. SRLDC explained that the exercise would validate preparedness to meet the similar situation in real-life and bring out the shortcomings and difficulties in the process which may need to be corrected accordingly.

c) AP agreed to provide some 132 kV radial loads for the mock drill exercise. AP was also informed that these radial loads would be operating at NEW grid frequency for the duration of the mock exercise. It was decided that AP would furnish the details to SRLDC for planning the proposed exercise.

11.1.3 Workshop for Black Start Procedure

The requirement and importance of “Black Start Procedure” was emphasized

by SRLDC. Accordingly suitable dates were sought from constituent-wise for

conducting workshop at their place. The following was the response of the

constituents:

AP: last week of August-2012

KA: 2nd week of September-2012

TN: would confirm date after concurrence from higher-up

KL: 3rd week of August-2012

SRLDC further detailed that there was no limit to the number of participants,

though the workshop would last for half-a-day. In the afternoon, presentations

on Regulations etc ( as per requirement) could be covered.

11.1.4 Requirement of synchronising facility at black start restoration critical substations

is given below: Sl. No.

Sync facility Requirement at station Status

1 Hubli To be provided during R&M works

2 ML Pura Sync Trolley available to be commissioned within 3 months from September – to be confirmed

3 Kayathar 110 KV Action being taken

4 Shornur Sync Trolley available

5 Chandrayangutta & city ring main stations

Yet to be provided


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In the meeting, the following was noted in regard to synchronising facility for

black start restoration:

Kayathar: TN informed that the administrative approval had been obtained and execution was under progress.

Shoranur: Kerala replied that though trolley was available, it had to be tested.

11.1.5 The updated status of mock drill of black start procedure furnished by SRLDC is

at Annexure – XXVI (for 2012).

11.1.6 In the meeting, Karnataka informed that Varahi mock drill had been completed.

11.2 Normative Vs. average actual ex-bus generation

SRLDC also presented the details of normative and average actual ex-bus

generation in respect of ISGS during the month of June-2012 which is given below.

It was noted that in respect of all the stations the actual DC was less than the

normative DC. The actual ex-bus generation in respect of NLC TS-II Stg-I, NLC TS-

II Stg-II, NLC TS I (Expn) and Kaiga was more than the actual DC.

Station May ’12 June ’12 (up to 24th)

Normative

DC Actual DC

Actual Ex‐Bus

Normative DC

Actual DC

Actual Ex‐Bus

RSTPS # 1to 6 &7 2417 2425 2437 2170 2154 2148 NLC TS‐II Stg‐I 472 471 475 504 492 494 NLC TS‐II Stg‐II 706 708 711 656 626 627 NLC TS‐I (Expn) 370 366 368 380 374 376 Talcher Stg‐II 1847 1831 1827 1773 1550 1546 Simhadri Stg‐II 467 467 457 341 294 291 MAPS 476 268 264 392 285 281 Kaiga 764 582 592 764 577 583

11.3 Utilisation of inter-regional links

SRLDC also presented details of the utilization of inter-regional links for the month of

June-2012. (Annexure - XXVII).

11.4 Tripping details



43

a) SRLDC had expressed serious concern since the information regarding tripping details with relay indications was awaited from nearly all the constituents. He had said that the entities should furnish the preliminary report on ‘events’ in compliance of IEGC Regulation, 5.9.6(a). Detailed report along with necessary information as mandated by IEGC should be followed. MS I/c, SRPC had said that as stressed earlier information needed to be continuously provided to SRLDC/SLDCs as they had to coordinate a number of activities and plan load generation balance in real time. If concrete information was not provided it would affect in taking optimal decisions in the interest of the grid. The issue was being followed up both in Protection & Operation Sub-Committee meetings but there was no noticeable improvement. Constituents should identify and implement a methodology so that the requisite information was available to the RLDC/RPC. SRPC was also apprised of the requirement in the recently concluded meeting held on 23rd December 2011.

b) SRLDC had said that as informed in the earlier meeting, they would like to have the ownership details of bays at various stations. POWERGRID had since then submitted the details to SRLDC.

c) In the 68th OCC meeting, constituents were requested by SRLDC for submission of detailed tripping events for further analysis and prevention of its repetitions. It was decided to discuss these things further in the forthcoming PCC meeting.

d) In the 71st OCC meeting:

i) SRLDC had said that Tripping reports from SR-I, SR-II PGCIL, APTRANSCO, KPTCL were being received. There were a total of tripping of 127 elements during the month. However tripping details along with relay indications for many of the Transmission Elements were yet to be received KGS reported that there was a tripping of 400 KV Kaiga - Guttur line on 29-04-2012 due to direct trip command received.

ii) SRLDC had stated that it was observed that in the recent past frequent tripping of 400 KV Vijayawada – Nellore D/C line was taking place on line to ground faults due to decapping of insulators. They had requested SRTS – I to take appropriate action since this was a major trunk 400 KV line carrying power from northern part to southern part of the Southern region.

11.4.2 In the meeting, SRLDC presented the details of tripping details. The status of

pending information for the month of June-2012 is enclosed as Annexure -

XXVIII.


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11.5 Wind Generation

SRLDC presented the day-wise Wind Generation pattern in respect of Karnataka &

Tamil Nadu for the period between 1st and 30th June-2012. Wind generation in

Tamil Nadu had varied from 50.25 MU (14th June 2012) to 82.54 MU (24th June

2012). Wind generation in Karnataka had varied from 12.22 MU (14th June 2012) to

29.78 MU (19th June 2012). SRLDC also informed that on 19th & 24th June, 2012

wind generation in SR had exceeded 100 MU. Details are furnished in Annexure -

XXIX.

11.6 Drawal Extremes 11.6.1 In the earlier meetings the following was noted:

a) In the 68th OCC, TN had suggested that data regarding Drawal Extremes displayed by SRLDC should also include details of frequency and schedule etc. so as to portray the correct picture. DGM, SRLDC said that drastic change in flows upto 790 MW during changeover took place on 400 KV GTY-NLM and GTY-HDY lines. TN said that any under-drawal at high frequency was also harmful to grid stability and should be treated on similar lines of over-drawal at lower frequency. TN therefore suggested that messages could be issued for under-drawal at high frequency also. SRLDC assured that they would look into this issue.

b) In the 69th OCC meeting, SRLDC had informed that due to very high quantum of load shedding in Tamil Nadu on account of deficit, the peak recorded was less than last year. TN informed that during February- 2011, while the load shedding was 403 MU, in February-2012 it was as high as 1535 MU. SRLDC further informed that from 2nd April-2012 onwards, as per the revised IEGC limits, the frequency on the lower limit stands increased to 49.7 Hz. MS i/c had said that at any point of time, grid discipline schedule would need to be maintained by adhering to the schedule. He also added there may be a need for issue of messages for under drawal at high frequency as discussed in earlier OCC Meeting.

11.6.2 SRLDC presented the statement of Drawal Extremes for the month of June-

2012. The details are given in the table below:

State

Extremes June-2012 Extremes till date Maximum Minimum Maximum Minimum

MW Date Time Block MW Date Time

Block MW Month MW Month

AP 3286 07-06-2012 39 1048 18-06-2012 70 4005 Aug-‘08 -1280 Aug-‘06 KAR 2307 07-06-2012 37 726 18-06-2012 20 2722 Sep-‘10 -947 Sep-‘09 KER 1890 17-06-2012 86 1084 14-06-2012 9 1890 Jun-‘12 -610 Oct-‘07 TN 2947 19-06-2012 9 1219 07-06-2012 37 4315 May-‘11 -100 Oct-‘03 PUDU 315 04-06-2012 77 133 24-06-2012 35 315 Jun-‘12 8 Dec-‘11


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The variations (i.e. = maximum - minimum) were: Andhra Pradesh (2238 MW),

Karnataka (1581 MW), Kerala (806 MW), Tamil Nadu (1728 MW) and

Pondicherry (182 MW).

11.7 400 kV UPCL-Shanthigram DC line

KPTCL informed that out of 529 locations, 529 stubs had been concreted,

524 towers erected and 336.44 CKM spans stringing were completed on 400 kV

UPCL-Shanthigram DC line.

11.8 Load shedding details & web based PSP system utility

It was noted in earlier OCC Meetings, that the hourly load shedding details should

be furnished online by the State SLDCs before 3 ‘O’ clock in respect of the previous

day through web. SRLDC had also requested the constituents to furnish the other

details through web based PSP system utility of SRLDC. For any assistance /

clarifications, OS department of SRLDC could be approached.

11.9 Monthly Time drift report receipt status

Constituents were requested to furnish the Time Drift Report regularly to SRLDC.

The status of Monthly Time drift report presented by SRLDC is given below:

Utility Status a) Andhra Pradesh No station is sending

b) Karnataka Nelamangala & Raichur only sending.

c) Tamil Nadu Only Gummidipoondi, Hosur, Kuzhithurai sending.

d) Puducherry Villianur not regular. e) ISGS:

MAPS Not sending. NLC Expn I Not regular.

11.10 ATC / TTC computations & Load Shedding details


a) SRLDC had pointed out that ATC / TTC computations were to be furnished by State utilities. LGBR for the next four months was needed to be furnished by all the constituents before 5th of every month for the purpose of ATC computations.


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b) In the 68th OCC meeting GM, SRLDC said that a workshop on “Available Transfer Capability (ATC) in Indian Context” was scheduled to be organized on 24.02.2012 at SRLDC, Bangalore and requested participation. DGM, SRLDC said that in future SRLDC would be requiring LGBR for the next five months instead of four months at present.

c) In the 69th OCC meeting, the efforts of SRLDC in conducting a workshop on ATC on 24th February, 2012 were appreciated. It was noted that KSEB had addressed a letter dated 5th March 2012 stressing the need for transparency in corridor availability for Day Ahead Transmission through PX. They had added that lack of knowledge on corridor availability had caused uncertainty in availability of power. In that meeting, SRLDC had reiterated their constraint in making available ATC for day ahead transaction through Power Exchange in their website.

11.10.2 In the meeting, SRLDC stated that hourly load shedding had to be provided in

order to calculate the shortage figures etc.

11.11 Mock Exercise for implementation of RRF


a) In the 64th OCC Meeting, SRLDC had informed that Hon’ble CERC had conducted a Workshop on 10th October 2011 at Bangalore regarding implementation of RRF mechanism. It was noted that CERC had directed to start mock exercise for the implementation of RRF w.e.f. 1st July 2011. SRLDC had taken up the issue with beneficiaries vide letter dated 5th July 2011 requesting them to make necessary arrangements. Following action was to be initiated by the States:

i) List of the wind farms and solar farms eligible for RRF provision.

ii) Details of contracts along with contracted price to be furnished to the concerned RLDC/RPC through the respective SLDC

iii) Forecasting data for wind & solar generation to be furnished to the concerned SLDC/RLDC/RPC

iv) 15 Minute block-wise data of schedule and actual generation from wind farms & solar farms as recorded in the SEMs on weekly basis to be furnished to the concerned SLDC/RLDC/RPC

v) Solar generators may be advised to give availability of the generator, weather forecasting, solar insolation, season and normal solar generation curve etc to the concerned RLDC for vetting of the generation schedules

vi) Furnish details of nodal developer who shall be responsible for coordinating the collective capacity on behalf of the group of developers on issues like SCADA, metering, scheduling, UI charges, RRF, forecasting data to the concerned SLDC/RLDC/RPC


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vii) States to identify nodal officer for coordinating on the above matters.

b) It was noted that SRLDC had informed in the earlier meetings, that Hon’ble Commission was viewing the implementation of the RRF mechanism seriously. As informed, it had also conducted a Workshop at Southern Region on 10th October 2011. SLDCs were the nodal / focal points for collecting the information in the States. Constituent states had been requested to furnish the relevant information to SRLDC/SRPC Secretariat. DGM, SRLDC had informed that a meeting was also scheduled to be held in this regard in New Delhi on 13th January 2012. The hearing before Hon’ble CERC was scheduled to be held on 24th January 2012.

c) MS i/c, SRPC had suggested that the process for furnishing the information could be initiated. The issue had also been taken up at TCC/SRPC forums. In the 67th meeting, it was noted that Hon’ble CERC had issued Orders in respect of Suo Motu Petition No.209 of 2011 for submission of data by SLDCs to NLDC by 15th December 2011.

d) It was noted that a Task Force had been set up by MNRE vide OM dated 28th March 2012 to resolve various issues relating to implementation of RRF mechanism under the Chairmanship of CEO, POSOCO. The Task Force was to finalize and submit its recommendations within a period of three months of the OM.

11.11.2 In the meeting, SRLDC informed that theDraft report of Task Force on RRF had

been submitted to MNRE. They also presented the Key Implementation Issues &

Task Force Recommendations (Annexure - XXX).

11.12 Weekly SEM Data Receipt Status

SRLDC informed about the delay in receipt of Weekly SEM data as given below:

Andhrapradesh Karnataka Tamilnadu

Stations No.of occassions Stations No.of

occassions Stations No.of occassions

KSTPS 2 Nelamangala 1 Alamathy 1 Tandur 1 BTPS 1

JSW 2 Sedam 1 Kadra 1 Kodasalli 1

Goa NPC POWERGRID Xeldam 1 Kaiga 1 Hiriyur 2

Kudamkulam 1 Mysore 1 Pondicherry 1

NLC NTECL Arasur 1 NLC II Expn 1 Vallur 1 Cochin 1


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11.13 Protection circuits healthiness and availability certificate

With regard to declaration of availability & healthiness of various protection /

defence mechanism schemes in SR , SRLDC informed that the same was yet to be

received from PONDY, NTPC Talcher, NLC TS-II,TS-II (Expn), SR-I.

11.14 Pending data for Annual Report /LGBR

SRLDC suggested that the monthly portion of the data pertaining to the Annual

Report be kept ready every month to avoid the delay in releasing the report.

Regarding the requirement of off-peak data for LGBR-148, AP stated that their

peaks were at 5.45 AM and 12.45 PM and queried which data had to be submitted.

After discussions, it was agreed that Members could submit the data related to the

regional off-peak timings.

11.15 Split-up details of Non Conventional Energy Sources generation

SRLDC requested that states may please provide split-up details of Non

Conventional Energy Sources generation for SOLAR, BIOMASS, WIND,

BIOGASSE & SMALL HYDELS in the monthly data.

11.16 Operating code from SRLDC In response to a query from AP about whether operations like outage of a line or

opening a bus-coupler would require a code from SRLDC, it was clarified by SRLDC

that any switching operation which would change the system configuration had to

take code from SRLDC.

11.17 DC Declaration of NLC TS II

SRLDC stated that the DC by NLC TSII during peak hours was less than rest of the

duration and requested NLC to initiate corrective action. NLC stated that the

constraints with regard to mines load had already been brought to the attention of

the forum. NLC was requested to approach Hon’ble CERC in the form of a petition in

case they desired any exemption in this regard.

11.18 Connection Agreement

SRLDC requested the utilities to submit copies of the connection agreement with

CTU at the earliest in line with the CERC orders.


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11.19 Overloading of Tirunelveli – Kayathar line SRLDC informed that Tirunelveli – Kayathar line and also 400 KV ICTs at Tirunelveli

& Madurai were overloaded and may need a SPS scheme. It was decided to

discuss the issue in the next meeting of the PCC.

11.20 Closing of issues already deliberated

It was noted that issues such as SPS at Hosur (approved in 19th SRPC meeting),

Scheduling of NTPC-Kayamkulam (started scheduling in July-2012), Start-up power

for NLC Stage-II expansion (already availing power as HT consumer), revised logic

for SPS for HVDC Talcher – Kolar link (Already in operation) and Scheduling of

Vallur JV (For the time being scheduling being carried out by SRLDC) were

considered settled and closed.

12. Maintenance Schedule of Generating Units

12.1 Reviewed & updated Outage Plan for the year 2012-13 is available at location

(http://www.srpc.kar.nic.in/website/2012/operation/Outage%20Plan%202012-13.pdf)

on the SRPC website.

12.2 Details of generating units under shut down (forced as well as planned) during

June-2012 are enclosed as Annexure - XXXI.

12.3 It was informed that biennial outage of Kaiga-2 unit was not informed to SRLDC in

real time. KGS agreed to look into this issue.

13. Shutdown Programme of Central Generating Stations

It had been noted in the earlier meetings that as per IEGC Provisions, RPCs are to

submit quarterly, half yearly reports to the Hon’ble Commission indicating deviations in

outages from the plan along with reasons. SRPC said that the reasons for outage

deviations also needed to be communicated to SRPC Secretariat.

14. Maintenance of Lines & ICTs completed in June - 2012

The planned maintenance of elements carried out by PGCIL/NLC during the month of

June-2012 is furnished at Annexure – XXXII.


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15. Shutdown Programme of Lines & ICTs Proposed

15.1 Planned shutdowns of 400 kV transmission elements of State Sector

In the earlier OCC meetings it had been recommended that the planned shutdowns

of 400 kV transmission elements of State Sector also needed to be approved

through OCC. State transmission utilities had been requested to furnish the planned

shutdowns of 400 kV transmission elements in their system for the year 2012-13.

15.2 The shutdowns of the ISTS system approved in the OCC meeting are given in

Annexure – XXXIII.

16. Capacity Addition in Southern Region

It had been decided in the SRPC meetings that the constituents would furnish the

status on upcoming Generating Schemes, since SRP Committee needed to be kept

informed of the likely capacity additions. SRPC requested the constituents to furnish

on a regular basis, the updated information on capacity additions including the IPPs,

to help apprise SRPC appropriately.

17. Review of Performance of ULDC Scheme

17.1 The following was noted in the earlier meetings:

a) As the constituents were aware SRLDC had approached Hon’ble CERC through a petition regarding establishment & maintenance of data and communication facilities and the same had been admitted. SRLDC informed that in the 18th SRPC Meeting, it was noted that all the constituents had assured to expedite and complete the pending works.

b) In the 68th OCC meeting, MS i/c SRPC had said that real time data terminal also needed to be available at SRPC Secretariat as per the regulations.

c) In the 69th OCC meeting, AP and Tamil Nadu pointed out that hotline facility with SRLDC was not functional for quite some period. SRLDC replied that it would address this problem and requested the constituents to take up the issue with the telecom operator at their end also.

d) In the 71st OCC meeting, APTRANSCO had informed that they were unable at times to get the data pertaining to NTPC Talcher / Ramagundam drawal accurately. SRLDC stated that variations could be due to change in schedule or transducer problem etc. SRLDC had therefore requested AP to submit all the relevant particulars so that the same could be studied and addressed. TN also informed that the PUNCOM link was not working.


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17.2 Status of pending field inputs

17.2.1 The following was the status intimated by SRLDC:

Standby Data Channel Status Non-availability of standby data channels at the following stations: Bhadravati Kudankulam Talcher RCI Bidadi, LANCO NLY TS 2 Expansion Trivandrum Hiriyur,Nelamangala Palakkadu Warangal Kochi

Voice Communication status (PUNCOM) Non-availability of voice communication at the following stations:

Bhadravathi Kolar HVDC NLY TS 2Expansion Gazuwaka MAPS NTPC Kayamkulam Hassan Munirabad Palakkadu Hiriyur Mysore Puduchery Kaiga Narendra Pugalur Kalivathnapattu Nellore Talcher HVDC Kochi NLC ST2 Trivandrum Kolar HVAC NLC TS 1Expansion

Internet communication

Reliable / Dedicated internet communication for system operation-Status of confirmation.

It was noted that though unmanned stations would not use permanent voice

communications on normal operations, but in case of disaster management

situation, as the people had to man the station and communicate with others

for restoration activities, permanent communication had to be in place at all the

unmanned stations also. PGCIL said that most of the lines were with OPGW

and communication would not be a problem for data, protection and voice

functions.

It was brought to the notice of the Members that PGCIL owned bays at Hoody

and Nelamangala substations of KPTCL were to be equipped with IEC 61850

protocol handling devices and AC bay kiosks and the cost of those upgrade

had to be shared by all the users. It was decided to put up the issue to the

Commercial Committee and then to TCC/SRPC.


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17.2.2 SRLDC informed about the status of pending field inputs (Annexure – XXXIV).

There were still 565 inputs pending as on 6th July 2012. SRLDC informed that

detailed pending inputs were also available on their web site and Members with

valid login details could download the details for their purpose. With regard to

NTPC Talcher, it was suggested that they may bilaterally discuss the issue with

POWERGRID so that the inputs could be made available at SRLDC.

17.2.3 In the 72nd OCC meeting, TN had said that data from Abisekhapatti (Tirunelveli)

unmanned substation, Edamon and Trivandrum substations were not received.

In response, SRLDC replied that TN could approach CPCC for obtaining data. In

response to SRLDC stating that at NTPC (Ramagundam) RTU card failure

problem had been existing since the year 2009, NTPC replied that barring 7 – 8

pending inputs all others had been attended.

17.2.4 In the meeting, TN reiterated that it was not getting the hourly interstate flows,

energy meter readings and bus voltage readings from 400 kV Abisekapatti-

Thiruruvanathapuram I & II and 220 kV Abhishekapetty-Edamon I & II. The

above readings were vital for computing the daily consumption particulars.

PGCIL replied that as the station was unmanned the data could be obtained only

from SCADA..

18. Vote of Thanks

MS i/c, SRPC thanked the Members for their active participation in the Meeting.

19. Date & Venue of the Next Meeting

The schedule for next OCC Meeting is as follows:

Meeting : 74th OCC of SRPC

Date : 13.08.2012 (Monday) Time : 10:30 Hours Venue : MAPS, Kalpakkam, Tamil Nadu

Documents

Southern Regional Power Committee (SRPC) · PDF fileSouthern Regional Power Committee (SRPC) ... KPTCL had earlier informed that the Power System Study Group ... KPTCL Zonal Chief