southern regional power committee, bangalore · declared quantum for aufr & df/dt relief and...

SOUTHERN REGIONAL POWER COMMITTEE, BANGALORE

Minutes of the 78th Meeting of the Operation Coordination Sub-Committee of

SRPC held at Bangalore on 11th December 2012

1. Introduction

1.1 The 78th meeting of the Operation Coordination Sub-Committee was held in SRPC,

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

Electricity Department, Puducherry had informed that they could not depute any

Member to the meeting due to administrative reasons.

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

participants especially from NTECL Vallur, to the 78th OCC Meeting. NTECL Vallur

was participating in the OCC Meeting for the first time. On behalf of the OCC forum,

Member Secretary i/c congratulated Shri P.R.Raghuram on his recent elevation as

Executive Director, SRLDC. He expressed concern over generating units such as

NTPC Simhadri-3 and NTECL Vallur being shutdown on account of coal shortage and

added that TANTRASNCO had also raised an agenda point on this issue. He informed

about the meeting that was organized on 26.11.2012 at Jegurupadu to discuss issues

relating to high voltage problem at Vemagiri complex.

Member Secretary i/c mentioned about the HVDC Talcher – Kolar bi-pole outage that

had been availed on 02nd December 2012 and thanked the constituents and also

NTPC, Talcher for extending necessary cooperation in this regard. He drew attention

of the Members on the outage proposal submitted by NTPC Talcher for the year

2013 -2014, where the scheduled outage of units was planned during July-August. He

requested NTPC and PGCIL to jointly examine, whether the planned HVDC bi pole

outage could be coordinated with the planned overhaul of Talcher unit. Regarding

Cyber security, he informed that a lecture by NLC Officer had been arranged during

the afternoon and requested the participants to attend the same. He placed on record

the appreciation of Karnataka for not receiving any violation message during

November 12.

Minutes of the 78th Meeting of OCC held at Bangalore on 11th December 2012 /36

Member Secretary i/c stated that an issue that needed to be discussed was regarding

declaration of COD of Unit 1 of Vallur STPS without availability of RGMO/FGMO. He

also added that implementation of measures identified in the Enquiry Committee Report

that had gone in to the disturbances in the NEW Grid was also a critical issue.

Fortnightly progress/updates in this regard were to be made available to CEA. He

requested the cooperation of the utilities in this regard.

a) Discussion on Under Frequency Relays

1. Member Secretary i/c initiated the discussions by seeking the status of

implementation of revised settings of UFR relays in the region. As per the

decision arrived at in the 20th SRPC meeting, the revised relay settings were to

be effective from 1st November, 2012. AP and Kerala had confirmed the

implementation of revised settings. It was informed that the revised settings of

UF relays had also been implemented in Karnataka, TN and Puducherry. The

utilities were requested to send written confirmation in this regard, if not already

done. SRLDC desired that the feeder-wise details should also contain the

expected relief.

2. SRLDC stated that the actual relief achievable in real time under each UFR

stage was also an issue of concern. It was also noted that the flows on the

identified feeders were being monitored on SCADA system and SRLDC had

been sending the details (hard and soft copies) once in 10 days to the

constituents.

3. KPTCL said that it could be observed that the percentage availability of actual

relief in respect of Karnataka system was relatively quite high.

4. KSEB stated that in case the load relief in respect of feeders that were not

being monitored on the SCADA system is also reckoned then the load relief will

match.

5. APTRANSCO clarified that anticipated relief figures were based on the

maximum demand, but currently with load shedding and other restrictions in

place the flow on the feeders had reduced .Hence the achievable actual relief

in real time was seen to be relatively less.

6. TN also stated that since load shedding was being carried out in the state to

manage the crisis, the achievable actual relief was less.


7. It was noted that SRLDC was intimating once in every 10 days the soft copy of

the observation details in this regard. The snap shot of SCADA picture of

feeders connected to UFR and df/dt was also being furnished. AP and

Karnataka expressed difficulties in implementation stating that since many

feeders, earmarked for AUFR and df/dt protection, were already under load

shedding due to extreme power shortage; it was difficult to provide further

relief. SRLDC stated that in such an event, the constituents needed to identify

the urban feeders where loads could be shed at least for Stage – III operation

for providing relief in case of contingency, as the last resort to safeguard

system security.

8. SRLDC informed that a Petition had been filed before Hon’ble CERC on this

issue since the low value of actual relief achievable in real time was a matter of

serious concern.

9. SRLDC also informed that all the Regional Entities had agreed in the 76th OCCM of SRPC to submit healthiness declaration on monthly basis in regard to protection system and critical system elements to SRLDC & SRPC. However, the same were not submitted in the last month by all the constituents except NLC. Member Secretary I/c requested all the Regional Entities to ensure submission of Healthiness declaration in the specified format during 1st week of every following month

b) Member Secretary i/c requested Shri A. Balan, Superintending Engineer to take up

the Agenda for discussions and accordingly the same was taken up.

2. Confirmation of the Minutes of 77th OCC Meeting The Minutes of the 77th OCC Meeting of SRPC held on 11th November, 2012 were

confirmed.

3. Major Issues

3.1 Physical regulatory measures by SRLDC on 16th November 2012 in AP System :

• Agenda:

Chief Engineer (SLDC), APTRANSCO via letter dated 16.11.2012 (Copy at Annexure - II) had informed that two ICTs at Gooty were opened at 0918 hrs of 16th November 2012 when AP was overdrawing at frequency 50.20 Hz and there were no transmission constraints while TNEB was under drawing by 300-350 MW.


• Deliberations:

SRLDC mentioned that in the absence of primary response (RGMO), non-availability of declared quantum for AUFR & df/dt relief and more time taken for manual demand management, constituents are advised to maintain drawal deviation near to 150 MW level.

It was noted that a petition had been filed before Hon’ble CERC by SRLDC.

3.2 Violation messages w.r.t. Kerala:

• Agenda:

Chief Engineer (Tran & S.O), KSEB vide letter dated 19th November 2012 had informed that Type A,B & C messages issued by SRLDC during some of the days in October 2012 (12,13,14 & 30) and November 2012 (Till 15th) were found to be issued erroneously and had requested to withdraw the same. Copy of this letter is furnished at Annexure - III.

• Deliberations: SRLDC informed that a letter stating the issuance of Type A, B, and C violation

messages were in order had already been sent to KSEB. It was informed by KSEB that

SCADA readings of frequency and drawl in their control room were varying from

SRLDC’s SCADA values. After deliberations on this issue it was decided to have joint

check up/reconciliation on 19th December 2012 of the SCADA values by SRLDC and

KSEB.

3.3 Delay in informing the revised drawal schedules to constituents:

• Agenda:

Chief Engineer (Tran, SO), KSEB vide letter dated 19.11.2012 & 23.11.2012(letters at Annexure - IV) had informed that there was delay in informing the revised drawal schedules to KSEB and had requested for early finalization of Form “D”.

• Deliberations:

SRLDC stated that to avert such instances, an alarm facility to KSEB shift operator also had since been provided, so that any change in the NR schedule is immediately available.

3.4 Proactive support from SRLDC:

• Agenda:

Chief Engineer (Tran , S.O), KSEB vide letter dated 19.11.2012 (letter at Annexure - V) had invited attention to the precarious energy position prevailing in Southern Region and expressed grave concern on the physical regulation measures imposed on the states by SRLDC with reference to drawal without considering system conditions. This had manifested through occasional high frequency conditions in the grid.


• Deliberations:

SRLDC mentioned that in the absence of primary response (RGMO), non-availability of declared quantum for AUFR & df/dt relief and more time taken for manual demand management, constituents are advised to maintain drawal deviation near to 150MW level. Also, caution / violation messages are being issued by SRLDC as decided in the Special TCC forum of SRPC

3.5 S1-S2 bid area SPS commissioned on 29.10.2012- Development of Logic & increase of ATC:

• Agenda:

Director Operation, TANTRANSCO vide letter dated 19th November 2012 (copy at Annexure - VI) had informed that even though SPS for S1-S2 bid area which was envisaged for enhanced power flow through 400 kV network to S2 area and to increase the ATC by 90 MW, had been commissioned on 29th October.2012, suitable logic had not been developed by PGCIL for the same. Further the ATC was also to be increased by 90 MW as earlier accepted.

• Deliberations: In the meeting, TANTRANSCO said that it had been asked to curtail its drawal citing

loading of 400 KV Hosur – Salem line, even when it was under drawing. For instance on

7th December 2012, Tamil Nadu was under drawing 206 MW, whereas the flow on 400

KV Hosur – Salem line was 550 MW. This line was a major outlet for KSEB drawal. The

STOA of KSEB should be calculated mainly considering the 400 KV Hosur – Salem line

loading. The schedule of KSEB had become twice that of their entitlement, which was a

cause for the above line loading. Hence a SPS scheme should also have been provided

in the Kerala system.

SRLDC stated that all relevant STOAs would be curtailed proportionately in case of any

transmission constraint situation. SRLDC further stated the sensitivity of KSEB system

with respect to the specified line flow was much lower. The same was deliberated with

details during finalization of SPS proposal. However they agreed to re-examine the

possibility of provision of SPS in Kerala system as suggested by TN.

3.6 Loss of Generation of Talcher Stage II Units:

• Agenda: Managing Director, TANTRANSCO vide letter dated 21.11.2012 (letter at Annexure-VII)

had informed about the wide gap between demand and supply of power in Tamil Nadu

system which had been aggravated by less generation from Talcher Stage II Units.


Director (Operation), TANTRANSCO vide letter dated 10.12.2012 (Annexure-VIII) had

further brought to the attention that lower availability from NTPC stations (Simhadri

Stage II, Vallur JV and Talcher Stage II) had deprived about 405 MW to TANGEDCO

thus worsening the power supply position in Tamil Nadu.

• Deliberations: TN again brought to attention of the OCC forum that coal shortage at NTPC plants was

affecting its due share from ISGS which was detrimental to the state grid, which was

already facing severe power shortages and load shedding.

NTPC stated that the matter was constantly being pursued at the appropriate level with

MCL.

All the constituents requested for maximum efforts of NTPC to maintain DC of ISGS

station near to Normative DC.

SRLDC requested all the Beneficiary Regional Entities to appropriately plan their LGBR

taking into account of loss of generation due to fuel shortage also, to avert difficulties in

real time demand management

3.7 Complying FGMO/RGMO requirements of IEGC by Simhadri Unit IV:

• Agenda: Letter dated 21.11.2012 from GM, SRLDC on this issue received is at Annexure-IX.

SRPC letter dated 22nd November 2012 addressed to Regional Executive Director (South), NTPC Secunderabad is at Annexure-X. NTPC had been requested to take

urgent action in this regard and intimate the same to SRPC/SRLDC

• Deliberations:

SRLDC stated that COD of NTPC Simhadri # 4 had been declared without RGMO

features being in place. SRLDC also stated that even after considerable time of the unit

commissioning, RGMO was not in place. Operation of new generating units also without

FGMO/RGMO was affecting system security. The matter regarding frequent high

excursions of SR frequency had already been highlighted to the forum. All units -whether

old and new needed to operate with RGMO features in accordance with clause 5.2 (f) of

IEGC Regulations. NTPC was again requested to expedite the implementation of

FROM/RGMO requirements.


3.8 NTECL Vallur COD and subsequent shutdown

TANTRANSCO pointed out that COD of Unit 1 of NTECL Vallur had been declared on

29th November 2012. Thereafter the unit had run for a couple of days only and

subsequently it was under outage which was continuing. NTECL replied that initially the

unit had been taken out due to coal shortage and subsequently to address the

condenser problems. NTECL also stated that though RGMO/FGMO features were

available with the unit, due to stabilizing and tuning problems it could not be activated. It

was noted that 72 hour test was not yet carried out for the unit. TN and Karnataka

expressed concern that while COD of a generating unit had been declared, immediately

thereafter it was not available due to various reasons.

NTPC, NTPC and NTECL clarified that, COD of the units was declared in accordance

with the CERC guidelines.

Karnataka emphasized that the 72-hours test of the generating unit needed to be

witnessed by its beneficiaries also, since this was a provision in most of the Power

Purchase Agreements (PPA). It informed that in Karnataka, PCKL and ESCOMs were

witnessing the 72-hour testing of the generating unit.

Further, all the beneficiary constituents mentioned that the CoD of new generating units

have to be declared only after completion of 72-hours full load test, compliance of

RGMO / FGMO features and adequate coal tie up etc.

The Beneficiary Constituents requested to treat the power injected into the grid by

NTECL, Vallur Unit 1 as infirm power only. Member Secretary i/c, SRPC noted that the

CoD of the Unit had already been declared by NTECL and the states were scheduling

the power from this unit.

The forum requested SRLDC to prepare a check list to be complied by the Generators

before declaring CoD of new unit.

3.9 KPTCL request for changing in 12% over drawl logic KPTCL had submitted an agenda item vide letter dated 6th December 2012 (Annexure-

XI). The quantum of power going outside the state is around 1000 MW and on the

increasing trend. Hence it real time it was difficult to limit the UI within 12 % of the drawal

schedule to operate the control area of demand of about 7500 MW. They also stated

that after 15th June 2013, the Karnataka CGS drawal schedule may become negative.

Hence they suggested that the overdrawal/under drawal be limited to 12 % of the CGS


entitlement instead of drawal schedule. However, States which were importing power

through MTOA/STOA etc stood to gain under the present methodology. SRLDC replied

that in accordance with the existing Regulations, 12% violation messages were being

generated based on the net schedule of the state and issued to the constituents. The

details were also being regularly submitted to Hon’ble CERC with a copy to the utilities.

SRLDC also stated that in case any state was aggrieved on the matter of the existing

methodology adopted, they could approach the appropriate forum for remedy.

3.10 Letter from CMD, POWERGRID

a) ED, SRLDC informed about the letter dated 26th November 2012 from CMD, POWERGRID (Letter copy at Annexure-XII) addressed to utilities. He requested all

the constituents initiate appropriate suitable measures as mentioned in the letter.

b) Regarding the issue of over drawal and physical regulation, AP and TN requested

SRLDC to give some time gap between issuing Type ‘C’ violation message and

subsequent physical regulation as discussed in the earlier OCC meeting. SRLDC

replied that the same was not possible under the prevailing conditions as explained

already.

c) SRLDC requested SRTS-I & II to increase the periodicity of pro-active Hotline

maintenance activities. It also suggested that thermo vision scanning of heavily

loaded corridors like Vijayawada-Nellore-Almathi D/C line, Gooty-Somanahalli,

Gooty-Hoody, Hosur-Salem, Somanahalli-Salem, Hiriyur-Nelamangala D/C,

Khammam-N'Sagar, N'sagar-Cuddapah D/C, Chitoor-SP Budur, Cuddapah-Kolar

and Guttur-Jindal-BTPS may be taken up immediately.

d) SRLDC also stated that in the past fog related trippings had been observed at

Kalpaka-Gazuwaka-Simhadri area, Kali complex, Hubli and Bidnal. Hence pre –

Winter Maintenance (FOG) action plan for insulator cleaning needed to be taken up

immediately.

e) POWERGRID agreed to review the suggestion of SRLDC.

3.11 Talcher Generation Schedule & Adhering to dispatch instructions of SRLDC

a) In the previous OCC meetings SRLDC had raised the issue regarding continuous

under injection by Talcher II. It was informed that the under generation at times was

as high as 200 MW irrespective of the frequency. SRLDC was finding it difficult to

monitor the ER- SR interconnector schedule vs actuals with such large deviation by


Talcher – II. SRLDC also mentioned that there were instances of delay in getting the

scheduled power from ER due to lesser generation by Talcher II.

NTPC had stated that the NEW Grid was running continuously at high frequency

which was the reason for Talcher II under generating. Also, NTPC, Talcher said that

the frequency of NEW Grid was taken as reference for its operation of UI.

The forum recalled the discussion of 77th OCC Meeting, where in NTPC was again

requested to maintain the generation as per schedule and desist from any under

injection. It was also clarified that Technical / Operational requirements over ride the

commercial aspects

b) It was noted that on 14th November 2012, the generation of Talcher II was 1685 MW

against schedule of 1830 MW and the under injection persisted. Hence SRLDC had

asked Talcher II to demonstrate the DC as per clause 6.4.19 of IEGC.

MS i/c noted the discussions on this issue in the previous OCC meeting also and

stated that the guidelines/instructions issued by SRLDC had to be implemented in

accordance with the Grid code

4. Follow up Issues

4.1 Coal Stock Position

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. Daily Coal stock position report as on 5th December, 2012 as downloaded from CEA website is furnished at Annexure - XIII. It

was noted that the coal stock position in Ramagundam, Simhadri, Bellary, Ennore, North

Chennai, Tuticorin and Talcher stations were less than for 7 days generation. As coal

stock position continued to be low, states were requested to implement appropriate

demand side management considering lower availability due to coal shortage.

b) OCC had again requested NTPC to furnish the information in the format as given at Annexure - XIV.

c) Coal Stock position as furnished by States is at Annexure – XV.


4.2 Physical and Cyber Security in power supply

a) In the Meeting (afternoon session) the following was noted:

i. Shri M. Coumarane, EE (Elect), NLC, Neyveli gave a presentation on Cyber

Security aspects. He covered data communications and security

mechanisms/algorithms with relation to cyber security measures. He also

stressed the need for physical security measures such as controlling/restricting

computer pen drives, especially in the SCADA environment. He suggested that

suitable security assessment needed to be carried out for each environment and

security policies framed and adopted. He also informed that tools such as

password crackers and packet analyzers were available to hackers, who were

capable to cause much damage to the power network data. He also cited some

attacks on SCADA systems that had taken place around the world. He also

stressed the need for association of the power utilities with research institutes for

developing and deploying cyber security measures. On a query from audience

whether wireless modes are also at the risk of hacking, he answered

affirmatively.

ii. In the Meeting MS, i/c emphasized the urgent need for proper and effective cyber

security measures to be in place. He requested the utilities to examine this

matter and revert back about the same to SRPC Secretariat.

b) Earlier deliberations:

In the 75th OCC meeting, it was noted that the Enquiry Committee which had gone into

the recent disturbances in NEW grid in its report submitted to MoP had emphasized the

need for improved telecom infra-structure for cyber security. It was also stated that for

smooth operation of grid systems, it was absolutely important that all the power

generating and distributing stations are connected on a very reliable telecom network.

The recommendations suggested are given below:

i. A proper network may be built up preferably using MPLS (Multi-Protocol

Label Switching) which is simple, cost effective and reliable. In remote

places where connectivity is a problem, the stations can be use dedicated

fiber cable from the nearest node.


ii. Since POWERGRID has its own fiber optic cables, practically covering all

major nodes and power stations. A proper communication/IT network

may be built using dedicated fibers to avoid any cyber-attack on the power

system. CTU and STUs had been requested to complete the process

within a time frame of one year.

iii. In the 77th OCC Meeting, it was also noted that the Enquiry Committee in

its report had stressed the need for improved telecom infrastructure for

cyber security.

4.3 Frequent Tripping of HVDC Bhadravathi

a) In the 75th OCC meeting, the following had been noted:

i. It was noted that General Manager (O&M), WRTS - I vide letter dated 10th

August 2012 had requested GM, SRLDC/WRLDC to schedule the power transfer

through HVDC Bhadravathi below 800 MW. Analyzing the power transfer through

HVDC Bhadravathi Link(from West to South) during the New Grid Disturbances

which had occurred on 30th and 31st July, it was opined that HVDC link could

provide good relief during emergency if enough power margin was left to meet

emergency requirement. It was pointed out that when SR frequency had dipped to

48.82 Hz, the frequency controller of HVDC Bhadravathi had acted and enhanced

the power transfer from 830 MW to 1097 MW. (West to South).

ii. In the 76th Meeting, it was noted that SRLDC vide letter dated 28th August 2012

had stressed the requirement for oscillation damping features in all the HVDC

installations to be kept in service.

b) It was noted that the oscillations study report was awaited. It was also noted that in the

Report submitted by the Enquiry Committee to look into the grid disturbance in NEW

GRID, it was suggested that an audit of devices such as HVDC should be done to

ensure that their stability features are enabled.

4.4 SPS for 400 KV Vijayawada – Nellore Line

a) In the Meeting, PGCIL said that tendering and procurement were under way at

various stages for different components of the scheme. LOA for DTPC had been

placed and the PLC was expected by December 12. AP informed that barring GMR

other IPPs were yet to confirm their readiness. It was suggested that the SPS

scheme be made operational initially with GMR for the time-being till other IPPs


were brought into the ambit. SRLDC requested APTRANSCO and POWERGRID

to expedite the issue.

b) Earlier deliberations:

• In the 75th OCC Meeting, it was noted that POWERGRID vide letter dated 30th

August 2012 had informed that administrative approval for the scheme had been

obtained and tendering was under progress. The time period for implementation

of the scheme would be around three months as earlier informed.

• It was noted that in the 20th SRPC Meeting, POWERGRID had intimated that the

SPS scheme would be implemented by November 2012. AP had also been

requested to coordinate with the balance IPPs. POWERGRID assured that the

work would be completed as per this schedule.

4.5 Implementation of the remedial measures suggested by the Enquiry committee

The matter regarding Remedial measures recommended by Enquiry committee on NEW

grid disturbance was discussed. As noted in earlier meeting, Chair Person, SRPC &

Chairman, TNEB had addressed a letter to SRPC Members in this regard. The same had

also been discussed in the Special TCC Meeting held on 08th November 2012. Member

Secretary i/c requested that utilities may kindly furnish the progress of implementation

measures on a regular basis to SRPC Secretariat enabling CEA to be informed

accordingly.

4.6 Mock Exercise for implementation of RRF (Renewable Regulatory Fund) a) 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. The actions

were to be initiated by the States were also listed.

b) The issue had also been taken up at TCC/SRPC forums. 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. 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.


c) In the 73rd OCC meeting, SRLDC had informed that the Draft report of Task Force on

RRF had been submitted to MNRE. They had also presented the Key Implementation

Issues & Task Force Recommendations.

4.7 Crisis Management Plan/Black Start Procedures

a) Requirement of synchronizing facility at critical substations is given in Annexure – XVI.

b) Mock drill for black start procedure: Details are furnished at Annexure–XVII.

c) In the 77th OCC Meeting it was noted that states had to prepare a station wise

activities for black start restoration as well as Mock exercise procedure and submit to

SRLDC for finalizing the consolidated procedures for the region.

d) KSEB had replied that it would submit the same within 1 or 2 weeks' time and that this

month it had planned mock drills on 17th, 20th and 27th in its plants.

e) KPCL/KPTCL were requested to submit the schedule for the 2nd half.

f) It was stressed and emphasized that the mock drill had to be point to point basis and

all the states would have to submit the station-wise revised procedures before next

OCC meeting.

g) KPCL informed that a letter had been sent to all the sites in this regard.

h) In the Meeting, the following was noted:

i. AP informed the forum that it had conducted a coordination meeting for

having point to point black start mock drill exercises and would submit details

within a month.

ii. KPTCL informed that it would be conducting black start mock drill for one of

the units of Sharavathy HEP shortly. SRLDC requested KPTCL to carry out

point to point black start mock drill exercise. SRLDC reiterated that station-

wise procedures for the black start mock drill exercise needed to be

prepared and subsequently the exercise had to be carried out from point to

point.

5. Grid Operation

Different aspects of grid operation were reviewed.


5.1 Grid events:

The following grid events were noted: a) COD of Unit 1 of NTECL Vallur was declared w.e.f 29th November 2012.

b) SRLDC released Reactive Power Document of SR 2013

c) Talcher – Kolar Bi-Pole Shut Down availed and works completed successfully on 02nd

December 2012.

5.2 Generation Capacity added - Details are furnished at Annexure-XVIII.

5.3 Transmission lines added - Details are furnished at Annexure-XVIII.

a) SRLDC also brought to attention the high line loading on 400 KV Hosur – Salem,

Somannahalli – Salem and Kurnool – Srisailam circuits. 5.4 New Substations added - Details are furnished at Annexure-XVIII.

SRLDC had requested the states to peruse the projected consumption figures etc in

respect of their systems as given in the 18th EPS for the purpose of planning of their

intra transmission system etc.

5.5 Existing Substations augmented – Details are furnished at Annexure-XVIII.

5.6 Maximum demand met & Average daily consumption – Details are furnished at Annexure-XIX.

5.7 Load duration curve - Details are furnished at Annexure – XX.

5.8 Daily consumption patterns - Details are furnished at Annexure – XXI.

5.9 Hydel Availability - Annexure – XXII.

It was noted that hydro storage was 2,366 MU less than last year [=10,065 – 7,699] as on 30th November, 2012.

5.10 Normative Vs. average actual ex-bus generation: Details are furnished at

Annexure – XXIII.

5.11 Utilization of inter-regional links

SRLDC also presented details of the utilization of inter-regional links for the month of November - 2012 (Annexure - XXIV).

5.12 Wind Generation – (Annexure – XXV)

a) TANTRANSCO had earlier been requested to devise suitable Contingency

arrangements to address wind variations. TANTRANSCO had stated that it

was carrying out adequate quantum of load shedding to manage such


contingency. KPTCL had informed that shortfall from wind energy was being

compensated through increased generation from UPCL and BTPS.

b) In the Meeting, SRLDC stated that SPS for containing overloading of 230 KV

lines for wind evacuation should be put in place by TN. Evacuation of wind

generation was an issue especially after the Kudankulam generation picked up.

TANTRANSCO stated they had devised effective manual intervention schemes

and number of substations and lines were under execution on fast-track mode.

SRLDC stressed that the remedial action needed to be automated.

5.13 Drawal Extremes

SRLDC presented the statement of Drawal Extremes for the month of November -

2012. The details are furnished in the Annexure – XXVI.

5.14 Monthly Time drift report receipt status: Details are furnished at Annexure – XXVII.

5.15 Weekly SEM Data Receipt Status

SRLDC informed about the details of delay in receipt of Weekly SEM data during November - 2012 which is furnished at Annexure –XXVIII.

5.16 Energy Charges of ISGS for the month of November-2012 as billed is at Annexure-

XXIX.

5.17 Grid frequency profile

Frequency profile during November - 2012:

a) Frequency remained within IEGC range (49.7 – 50.2 Hz): 91.85% i. Previous month (October-2012): 89.38 % of time

ii. Same month last year (November -2011): 93.60 % of time

b) Frequency remained below 49.7 Hz band for 4.16% of time c) Frequency remained above 50.2 Hz for 3.99% of time

d) Average frequency was 49.91 Hz.

e) Frequency histogram & Frequency duration curve: Details are furnished at Annexure – XXX.

5.18 High Frequency Grid Operation

Load changeover: It was stated by SRLDC that load changeover and resulting

frequency excursion instances were occurring at the end of almost every hour within

the constituent. SRLDC brought to attention the provisions of clause 5.2 (j) of IEGC.


No user was to cause sudden variation in its load by more than 100 MW without prior

intimation to and consent of the RLDC. Similarly no user should reduce the generating

unit output by more than 100 MW without prior intimation to and consent of the RLDC.

Member Secretary I/c SRPC, requested the co-operation of all the constituents for

strict compliance of clause 5.2 (j) of IEGC.

SRLDC re-iterated that implementation of Automated Demand Management is very

much essential in view of growing complexity of power system operation

5.19 Low Frequency Grid Operation a) Low frequency operation during November - 2012

Member Secretary i/c, SRPC said that the frequency of operation of the Southern

Regional Grid had been less than 49.7 Hz for about 4.16 % of the time during the

month of November - 2012. SRLDC stressed on proper management of load

generation balance in real time and highlighted the remedial measures to be

pursued to curb low frequency operation. SRLDC also emphasized the need for

effecting Demand side Management as per the Grouping of Loads details

furnished by SR constituents. Strict compliance action in response to SRLDC

messages (Type – A, B, C) and also reporting details of compliance through a

reply message was also emphasized.

b) Grid Code violation messages i. Details of caution/violation Type A, B & C messages issued by SRLDC to

the constituents during the month of November - 2012 are furnished at

Annexure – XXXI.

ii. Details of 12% violation messages pertaining to Over Drawal / Under

Injection while the frequency was below 49.8 Hz over a time block is

given in Annexure - XXXII.

c) Measures by constituents to improve the frequency i. APTRANSCO:

• Load shedding up to 2886 MW amounting to about 1255 MU had been

carried out during November -2012.

• APTRANSCO informed that even with purchases and resource

management, the State had to face demand & energy shortages.


• Details of Load relief imposed during the month of November -2012 are

furnished at Annexure - XXXIII.

ii. KPTCL:

• KPTCL informed that load shedding up to 1950 MW amounting to about

576 MU during the month had been carried out in the State.

• Strict grid discipline was maintained during November - 2012 and the

state had generated more power from hydro sources whenever possible

and supported the grid during periods of low frequency.

iii. KSEB:

• Need based load shedding up to 500 MW amounting to about 76 MU

had been carried out during November -2012.

• KSEB informed that with purchases they were able to maintain load

generation balance in their system. Measures taken by KSEB to

maintain grid discipline include cyclic load restrictions and switching off

of identified radial feeders as directed by SRLDC.

iv. TANTRANSCO:

• TANTRANSCO said that load shedding up to 5156 MW amounting to

about 1834 MU was carried out during the month.

• They briefed about the load restriction measures in their system for

November -2012 which is given below:

40% in respect of HT Industrial and Commercial consumers 1 hour Load Shedding for Chennai (from 0800 to 1800 hrs.) 3 hour Load Shedding for urban and rural Areas (from 0600 to

1800 hrs.) 10 % peak hour restrictions to HT and Commercial consumers. Agriculture was being fed 6 hours of three phase supply in day

time and 3 hours of three phase supply in night time.

6. Voltage Profile

6.1 High Voltage (Annexure-XXXIV)

a) It was noted that nodes at Nagarjunsagar (433 kV), Vijayawada (435 kV),

Hyderabad (437 kV), Hiriyur (431 kV), Vemagiri (435 kV), Gooty (432 kV),


Srisailam (435 kV), Kurnool (435 kV), Raichur (431 kV) and Guttur (434 kV) were

facing high voltage scenario.

b) SRLDC requested all the Regional Entities that the GT / ICT tap position of all

High voltage locations shall be kept corresponding to the output voltage of

400kV. The action taken in this regard needs to be communicated to SRLDC &

SRPC.

c) SRLDC also requested the generating stations in the High Voltage Zone to

absorb MVAR as per Capability Curve limit.

d) There had been 90 tripping due to over voltage of the 400 kV lines during the

month.

e) It was also noted that Madurai-Pugalur II, Thrissur- Kochi I, Kalpakka-Vemagiri

I,II & IV, Vijayawada – LANCO I, Vijayawada-Vemagiri I II & IV, Talaguppa-

Nelamangala II, Tirunelveli- Kudankulam I, II & IV, Vemagiri- Simhadri I, Mysore-

Hassan I, Madurai- Thirunelveli I,Udumalpet-Thirunelveli I & II,

Thiruvanathapuram- Thirunelveli II, Ramagundam –Hyderabad IV, Kaiga- Guttur

I, Guttur- Narendra I & II, Hassan-UPCL I, Srisailam-Mamidipalli I, lines were

kept open for more than 3 days due to over voltages.

f) SRLDC again emphasized that Line opening would be the last resort by SRLDC

after receipt of message from the constituents. Details of measures taken

needed to be communicated in the line opening request message.

g) Executive Director, SRLDC suggested for a special meeting with members from

major generating stations to address the High Voltage & RGMO issues.

h) 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 – XXXV.

6.2 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 subsequent 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 had 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 on Power System Planning.

6.3 Requirement of reactor at Vemagiri Complex

It had been noted that the requirement of reactor at Vemagiri Complex had been

deliberated in earlier Standing Committee Meetings and APTRANSCO was to take a call

on this issue. Further developments in this regard were awaited from APTRANSCO.

SRLDC vide letter dated 12th June 2012 addressed to APTRANSCO had again

requested that the commissioning of bus reactor at Vemagiri be expedited.

APTRANSCO was asked to furnish the status of action in this regard.

6.4 Low voltage

a) In the Meeting it was again expressed that the utilities needed to install under

voltage relays as mandated in IEGC Regulations to control low voltages at the

400 kV nodes. It was noted that TN had agreed for low voltage protection

relays and it was requested to intimate the details of implementation.

b) SRLDC informed that certain 400 kV nodes such as at Thiruvananthapuram

(399 kV), Trichur (380 kV), Chennai (394 kV), Kalivanthapattu (387 kV),

Karaikudi (390 kV), Udumalpet (384 kV) were facing LV issues.

c) It was also noted that in the recent TCC/SRPC Meetings, the Committee had

approved installation of Under Voltage relays as proposed by SRLDC.

d) It was noted that installation of under voltage relays was being implemented by

Tamil Nadu and details from Karnataka were awaited.

e) Member Secretary, SRPC requested the constituents to submit the details

action plan for implementation of Under Voltage Relay Schemes.

6.5 Installation of Shunt Capacitors The progress of installation of HT shunt capacitors was reviewed and the details are furnished in Annexure – XXXVI.

6.6 Absorption / Injection of VARs by Generators (Annexure-XXXVII)

a) Hon’ble CERC Order dated 23.12.2009 merited attention in this regard. It had been

stated in the Order that all agencies needed to provide required reactive

compensation thus avoiding the need for exchange of reactive power to/from ISTS

and maintain ISTS voltage within specific range.


b) In the 75th OCC Meeting, efforts of APGENCO/APTRANSCO in changing the Tap

position of VTPS Unit 7 from 4 to 5 as suggested by SRLDC were appreciated.

SRLDC requested APTRANSCO to ascertain the present Tap position whether it is

corresponding to 400kV level and furnish the same to them.

c) SRLDC had addressed letter dated 25th July 2012 to APTRANSCO bringing to

attention the over voltage in Vemagiri area. Due to low gas availability the

generation in the complex was low, further adding to the problem of high voltage.

APTRANSCO had been requested to urge the generators to adopt the proposed tap

settings at the earliest. APTRANSCO informed that Generators had communicated

the difficulties such as under excitation limiter alarm faced by them when they tried

to change the tap positions as suggested by SRLDC/SRPC.

d) In the 77th OCC Meeting SRLDC had expressed the concern about high voltage at

400 kV Vemagiri Complex and requested to change the GTs Tap Position to

Nominal voltage i.e. 400 kV of Gas Stations connected to Vemagiri Sub Station. A

Meeting had been scheduled on 26th November 2012 at Vemagiri which was to be

attended by officers of SRPC and SRLDC also.

e) In the 77th OCC Meeting, the following had been noted:

i) NTPC had stated that despite most of its generating units absorbing reactive

power, the high voltage situation in the grid could not be contained. NTPC

requested the OCC forum to evolve a strategic guideline for MVAR absorption,

reactor installation and opening of lines etc for containing persistent high

voltages especially in the S1 bid area. The same had also been sought by the

top management of NTPC.

ii) SRLDC had pointed out that reactor installation by NTPC at Simhadri and

Ramagundam was pending for considerable period. The Tap Position should

be close to 400kV of all GT’s / ICT’s .Further tap position of new generating

units should correspond to 400kV before COD. It was also informed that

despite generating about 350 MW, Simhadri IV was absorbing only 40 to 50

MVAR. NTPC said that since 2006, a number of grid elements had been

added /removed from the grid but the high voltage situation was persisting. A

review of reactive power requirement could be undertaken by conducting fresh

study for identifying the quantum of compensation requirement and location. It

was noted that SRLDC had earlier proposed additional reactors at seven

locations. OCC agreed to recommend the proposed reactors at these seven


locations as suggested by SRLDC to TCC/ SRPC for approval. SRLDC stated

that on 31.10.2012, the day of cyclone ‘Nilam’, reactor at NLC was not there

and the same was not informed to SRLDC too.

iii) SRLDC had stated that a time frame for changing the ICT/GT tap positions be

decided. SRLDC stated that it was yet to obtain the tap changing information

from VTPS. MS i/c informed that a Meeting was proposed to be held on 26th

November.2012 with the generators in the Vemagiri Complex. The matter

could thus be reviewed in the next meeting of OCC.

f) In the Meeting, the following was noted:

iv) Member Secretary i/c stated that as decided in the last OCC Meeting, a

meeting to address over voltage problems in Vemagiri Complex had taken

place on 26th November 2012 at Jegurupadu with the participation of SRLDC,

SRPC, APTRANSCO, & IPPs at Vemagiri complex. The minutes of the meeting is enclosed at Annexure-XXXVIII. It was also noted that a letter

seeking details of nominal voltage with associated tap position and present

voltage with associated tap position for the month of November-2012 had

been addressed to the concerned generators.

v) SRLDC recalled discussion on this issue in the last OCC meeting, and

stressed that tap position had to be set corresponding to nominal voltage of

400 kV. PGCIL suggested that line opening could start at 420 kV itself.

RLDC reiterated that opening of lines on account of high voltage needed to be

carried out prudently, since it would also resulted in network depletion.

6.7 Grid operation data for November - 2012 is enclosed as Appendix - A.

6.8 Facilitation of Inter-State/Inter-Regional transfer of power

a) Bilateral energy exchanges

On a review of the bilateral exchanges made by the constituents and also by

the embedded IPPs during November - 2012, the following was noted:

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

ii. Imports (intra-regional) were carried out by: Andhra Pradesh.

iii. Exports (Inter-Regional: Nil

iv. Exports (intra-regional) were carried out by Andhra Pradesh, Karnataka.


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

XXXIX.

c) It was also noted that Andhra Pradesh, Karnataka, Kerala & Tamil Nadu had

furnished the relevant details regarding energy exchanges through the Power Exchanges (Annexure - XL).

6.9 Pump mode operation of Kadamparai and Srisailam It was noted that Kadamparai machines had consumed about 13.2 MU in pump mode

during November - 2012.

6.10 IPP Utilization

OCC was also apprised of the PLFs of the IPPs operating in Southern Region during

the month of November - 2012 (Annexure - XLI).

6.11 Minimum to Maximum demand ratio

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

month of November - 2012 are furnished in Annexure - XLII.

7. 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

furnished at Annexure - LXIII.

b) SRLDC presented the list of important generating schemes, transmission lines and

generation evacuation lines under construction (Annexure – LXIV).

c) In the meeting, TANTRANSCO informed that court cases halting 400 KV Mettur

Station- III – Arasur line were over in favour of the Govt. and the line was likely to

be ready by next month (January-2013). It further added that court cases in regard

to 400 KV NCTPS St II -Almathi line was also over in favour of Govt. It was noted

that Transformer was not yet ready at Almathi and was in the tendering stage.

d) KPTCL informed that works were under progress in respect of the third 500 MVA

400/220 KV ICT at Nelamangala and Hoody.

e) In the 76th OCC Meeting, APTRANSCO had said that review meetings were

already being held in the STU and there were concerned departments/divisions to


monitor the progress of the lines. KTPCL had informed that appropriate feedback

was being given to the higher management and the Project Monitoring Group was

reviewing the projects regularly. ROW problems were being faced by KPTCL.

TANTRANSCO had informed that the projects were being reviewed even at Chief

Secretary level. There were a number of court cases involved for the transmission

and evacuation schemes. MS i/c had said that the Enquiry Committee that had

gone into details of grid disturbance on 30/31.07.2012 had also recommended for

development of intra state transmission system to avoid frequent congestion. After

discussions, it had been agreed that a meeting of Officers from concerned

monitoring divisions both from the transmission and generation utilities be

convened so as to have better clarity of the status and progress of schemes.

SRLDC had expressed concern over the status of evacuation lines for North

Chennai & Mettur Generation as well as Status of 400 KV VTPS-Malkaram-

Narsapur D/C line. SRLDC also re-iterated that the Associated Transmission

System shall be made available prior to declaration of CoD of generating Units to

avert transmission constraints and thereby bottle-up of generation.

f) In the 77th OCC Meeting the following was noted:

i) SRLDC had desired that Attached Transmission System (ATS) of

generating stations was also to be monitored for progress.

ii) Bellary TPS was asked to implement RGMO feature before declaring COD

of Unit 2. KPCL informed that though 72 hours full load test had been taken

up, COD of the unit was yet to be declared.

iii) NTPC had replied that before COD, the capability of the unit to deliver full

load commercially was being ascertained. However, Tuning of the unit for

various desired parameters such as throttle pressure under load reduction

conditions etc would require some time after COD, it being a continuous

process. It added that Ramagundam unit-7 was recently tuned. It also

stated that RGMO features for Simhadri #4 would be achieved after tuning

by the supplier M/s BHEL. MS i/c suggested that this issue be brought to

the attention of higher management of NTPC. SRLDC suggested that in

case RGMO implementation was not possible immediately, NTPC needed

to obtain exemption from Hon’ble CERC quoting the technical difficulties.


iv) SRLDC had informed that Standby data channel was not available for

NTECL Vallur, which needed to be provided before COD of the unit which

was expected shortly.

v) SRLDC had queried on the status of NCTPS and its evacuating lines - to

SV Chatram and Almathy. TN responded that tower foundation and tower

erection works had been affected due to court case, ROW issues etc.

SRLDC also enquired about the status in respect of the 3rd ICT at Hoody

and Nelamangala.

vi) It was informed that in respect of the 400 KV line from Mettur St III to

Arasur, the matter was before the Honorable Supreme Court. Till the ROW

issues were resolved, the existing lines would be used for power

evacuation. It was noted that Mettur Stage-III had achieved generation level

of about 608 MW. SRLDC stated that RGMO features should also be in

place for the unit. Further any unit should be brought on bars only with the

ATS in place.

vii) Member Secretary i/c had suggested that a format could be prepared and

circulated for obtaining status of various ongoing projects and submission

to the forum.

viii) 230 KV Hiriyur-Gowribidanur line was held up due to ROW problem. It was

noted that Somanahalli – Malur line was planned many years back and its

relevance in the present system conditions may need review.

ix) KKNP officials had informed that criticality of Unit 1 was expected on 3rd or

4th December-2012 .Initially around 300 MW of power was expected to be

generated. After inspection and parameter tuning, the power would be

increased in stages to levels of 50%, 75%, 90% and 100%.

x) It was informed that the 2 x 800 MW units of APGENCO at Krishnapattnam

were expected to be synchronized during June 2013 and December 2013

respectively. Works on the associated 400 KV lines in the scope of

APTRANSCO were in progress and would match the schedule of the units.

Rayalaseema TPS Stage IV (600 MW) was expected by August 2014.

xi) SRLDC had suggested that since KKNP unit would be operational shortly,

officials from that plant could attend all the Sub Committee Meetings.


xii) SRLDC also requested that submission of data pertaining to capacitor

banks, tap positions of GT/ICT and generator capability curve mentioning

the addition and deletion of elements had to be expedited to SRDLC for

updating of the Reactive power management document.

xiii) MS i/c had proposed a separate Meeting for review of the progress of the

various power projects/ATS in the Region.

8. Generation targets/Annual Outage Plan

8.1 Generation Target/ Annual Outage Plan for the year 2012 – 13 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. It had been noted in 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. It

was requested that the reasons for outage deviations also needed to be

communicated to SRPC Secretariat.

8.2 Electricity Generation Review during the period April to November - 2012 CEA has been monitoring the performance of all generating stations in the

country with a view to improve the availability of power in the country. During the

Periodic Review undertaken in CEA, it had been observed that the following

thermal stations of SR had not performed as per the target fixed for them during

the period April to September 2012.

a) Raichur TPS (KPCL) b) Kothagudem TPS (Andhra Pradesh).

RTPS has furnished the reasons and the same is at Annexure- XLV.

It was requested that APTRANSCO may please examine the matter and furnish

specific reasons which had caused shortfall in generation to OPM Division CEA.

It was also requested that strategy/action plan decided to increase generation so

that the loss of generation suffered during the period April to November 2012 be

made up during the remaining period of the year 2012-13.


8.3 LGBR forecasted figures vs. Actual Figures

a) It was noted that there were certain variations between actual and forecasted

availability and requirement LGBR figures by more than 10% in respect of

States during the month of November – 2012. The details of the same are

given at Annexure-XLVI.

8.4 MoP Gross generation: Targets vs. Actual

Details showing more than 10% shortfall in the gross generation with respect to MoP approved target figures for the month of November - 2012 are at Annexure -

XLVII.

8.5 Forced outages of thermal units

OCC was apprised of the forced thermal outages of more than 24 hours duration during the month of November - 2012 (Annexure – XLVIII). It was noted that the

forced outages of thermal units had varied between 3.7 and 7.70 % during the

month of November - 2012.

8.6 Prolonged outages

a) OCC was apprised of the prolonged outages in the Southern Region during the month of November - 2012 (Annexure - XLIX).

b) SRLDC expressed concern over prolonged outage of Srisailam pumps and

installation of reactor at Guttur.

c) SRLDC requested the constituents to furnish the detailed action plan for

restoration of elements under prolonged outage

8.7 Generation targets for the year 2013 - 14

a) The Annual Generation targets & Outage Planning of Generating Units and

Transmission Elements are under preparation. Certain Constituents /

Generators had not furnished the required data despite reminders in this

regard. The status of receipt of data for the Generation Targets and Outage

Planning for the year 2013 -14 is as shown below:


Name of the Constituent / Generator

Annual Generation Target Data submitted to SRPC

Outage Planning Data submitted to SRPC

APTRANSCO

KPTCL

KSEB

TANTRANSCO

PED

NTPC : Ramagundam

Talcher

Simhadri

NLC : TS - 1

TS - 1 Exp

TS - 2

TS - 2 Exp

NPCIL : Kalpakkam

Kaiga Stg - 1

Kaiga Stg - 2

SRTS – I

SRTS – II

b) It was requested that all constituents/Generators who had not furnished the

details may please furnish the same by 24th December 2012 positively.

c) NTPC had revised their Annual Outage Programme for the year 2013-14 as

requested by OCC forum in the last OCC meeting. The revised schedule is at Annexure-L. It was noted that outage of Talcher II units had been scheduled

during July-August. Member Secretary i/c requested NTPC and PGCIL to kindly


coordinate regarding the matching of HVDC bipole outage with overhaul of

Talcher II units.

9. Availability & Consumption

9.1 Anticipated Availability and Consumption

The anticipated availability and consumption as furnished by the states for the

next two months – December-2012 & January-2013 - are furnished in Annexure – LI.

9.2. Review of the availability during November - 2012

The anticipated availability as furnished in the 77th OCC against the actual availability is at Annexure – LII.

10. Compliance of IEGC guidelines/information needs to be furnished/ pending implementations

10.1 Automatic Demand Management Schemes

a) 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.

b) It was noted that Andhra Pradesh, Kerala, Tamil Nadu and Puducherry had implemented

the scheme.

c) KPTCL had informed that all ESCOMS had taken following measures for implementation

of Automatic Demand Management scheme.

i. Provided rostering of 11 kV rural feeders & it will be operated during peak

hours for controlling the agricultural demand.

ii. Replacing conventional incandescent bulbs by CFL bulbs provided by

BESCOM at concessional rates to consumers and it is in vague.

iii. As per directives of KERC, ESCOMs are implementing the scheme of

providing TOD meters to EHT & HT consumers and differential tariffs are

imposed to control the demand during the peak hours. At present CESC &

MESCOM have already implemented.

iv. All the distribution companies are implementing the NIRANTRA JYOTHI

Scheme for bifurcating the agricultural loads of 11 kV rural feeders.


d) It was suggested that constituents could identify other Demand Management Schemes

other than Automatic Load Shedding Schemes.

e) In the Meeting, SRLDC again stressed the need for implementation of Automatic

Demand Management Scheme through appropriate PLC Logic.

10.2 Automatic Load Disconnection Schemes for overdrawing constituents

a) 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:

b) 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

c) APTRANSCO, KSEB, TNEB and Puducherry had implemented the scheme for remote

tripping from SLDC.

d) KPTCL had informed that 350 MW of load relief through remote tripping of loads during

crisis period had been implemented and operationalised from SLDC.

e) It was noted that the Automatic Load Disconnection Scheme was part of Automatic

Demand Management Scheme which had been discussed above.

10.3 Arranging of interruptible loads in four groups

a) In the 76th OCC Meeting the following had been discussed and noted:

APTRANSCO had informed that for a period of 10 to 14 hours load shedding of about

5000 MW was in force (except railways). The feeders – domestic, commercial, industrial

consumers were mixed in nature and hence it was difficult and not feasible to segregate

the consumers feeder-wise for purpose of load shedding etc. They added that projected

relief to be obtained through grouping and restriction of loads would be under ideal


conditions and may not be feasible all the time. Industries in the state were facing 40%

power cut. Hyderabad city loads were also facing 3 hours load shedding, while in Towns

and Municipalities the duration was 6 hours. APTRANSCO also stated that the feeder

relief quantum was assessed based on maximum demand of about 12,000 – 13,000

MW. However, since the demand had come down to about 8000 MW, the quantum

would get reduced proportionately. KPTCL had stated that in addition to four groups of

loads for shedding purpose, other mechanisms to control the loads were available in the

state. They added that there were about 9,500 feeders of 11 kV in the state which could

be tripped by the SLDC in case of contingency. SRLDC informed that periodic reports in

this regard were already being submitted to SRPC. As noted in the recent TCC/SRPC

Meetings, the present status of defense mechanism in SR was a matter of concern. The

expected relief was not forthcoming. States had been requested to identify feeders such

that the desired quantum of relief as agreed would be ensured. MS i/c had stated that

grouping of loads etc were to be implemented as per the provisions of IEGC. The loads

were to be grouped in such a manner that there is no over lapping between the different

groups of loads. After discussions, it had been agreed that this matter would be put up to

the higher management of the states.

b) In the 77th OCC meeting, MS i/c stated that this issue had been discussed in the Special

TCC Meeting held on 8th November 2012. Utilities had agreed to initiate measures to

ensure that the desired quantum of relief was obtained.

10.4 Restricted Governor Mode of Operation (RGMO)

SRLDC presented the RGMO Analysis Summary (details in Annexure - LIII). It was

noted that in the recent TCC/SRPC Meetings it was also noted that the performance of

RGMO in the region was minimal.

There was inadequate response from thermal generating units and the details are

presented by SRLDC

SRLDC requested confirmation from all the major generating units that the RGMO

setting has been revised as per the requirement of IEGC (Amendments) Regulation

2012. Also requested the constituents to ensure RGMO performance through Manual

control of FGMO wherever RGMO setting is not possible.

Cooperation of the generators had been sought to check the response and initiate

remedial measures.


It was emphasized that Restricted Governor Mode of Operation of all eligible machines

shall be ensured in place as one Remedial Measure to be pursued to contain High

Frequency excursion.

10.5 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.

10.6 Notified Power Cuts

Member Secretary 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

through written communication to appraise MoP/GoI appropriately.

10.7 Drawal Extremes and Physical Regulation Measures

a) The issues had been deliberated in the 75th and 76th OCC meetings. The constituents

had expressed concern about imposing physical regulations without proper intimation

and explained how badly it affected their system. It was stated that SRLDC was not

allowing over drawal of more than 150 MW even when frequency was above 50 Hz.

They had requested that over drawal at higher frequency could be permitted as

stipulated in IEGC without endangering the security of Grid. Else the frequency could

rise further higher, thus endangering the system.

b) SRLDC had quoted the clauses as per the IEGC and UI regulations and informed that

overdrawal could be allowed only within the limits as stipulated in the same. In case the

over drawal quantum was higher, it would take more time to reduce their drawal in case

of contingencies which would only drag the system to insecure operating conditions.

They had also highlighted that system protection schemes like AUFR, df/dt, SPSs were

not acting to the desired level. Load Forecasting Day wise Block wise needed to be

carried out for better system operation. Deviation from the injection / drawal schedule

shall be strictly restricted to within the limit specified by the relevant CERC Regulations.

Even while the frequency is above 49.8 Hz, the over drawal quantum shall be such that

it will not endanger the Line loading or lead to violation of IEGC / UI regulations in case

of any contingency in the system. Constituents were also requested to maintain their

Load Generation Balance in order to maintain SIL of Lines.


c) After deliberations, it had been agreed that SRLDC would review these incidents. It was

felt prudent that proper written intimation be given before imposing physical regulation

measures. However, the SRLDC’s endeavor for safe and secure system operation was

appreciated by the Forum. SRLDC was however requested that any intervention

including load disconnection through implementation of physical regulation measures at

ISTS drawal point of states be carried out subsequent to issuance of violation messages

and non-compliance observed, if any.

Details of Physical regulations imposed by SRLDC on different grid elements during November 2012 is at Annexure-LIV.

10.8 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.

10.9 ATC / TTC computations SRLDC had pointed out that ATC / TTC computations were to be furnished by State

utilities. LGBR for the next five months was needed to be furnished by all the constituents

before 5th of every month for the purpose of ATC computations.

10.10 Tripping details

a) The status of pending information for the month of November -2012 is enclosed

as Annexure–LV. SRLDC informed that in accordance with the IEGC

Regulations, tripping details had to be submitted within 24-hour time period.

Hence non -submission of the same could be reckoned as grid code violation.

b) SRLDC again requested the constituents to submit the DL/EL details within 24

hours of tripping in accordance with the grid code. They added that they would

be compelled to approach Hon’ble CERC in this regard in case there was no

perceptible improvement soon.

11. System Protection

11.1 Under Frequency Relay - Trippings for the month of November 2012 are furnished at Annexure-LVI.


It was noted that in the recent TCC/SRPC Meetings, the Committee had approved the

revised AUFR settings for implementation. It had also been agreed that the

Constituents would implement the new UFR settings within a period of one month (by

1st November, 2012). The utilities were requested to inform that the UFR settings had

been revised, in case they had not carried out the same. The feeder wise details submitted by KPTCL, TNEB and Puducherry are furnished at Annexure-LVI A.

11.2 df/dt Protection System - Tripping details for the month of November 2012 are furnished at Annexure – LVI.

11.3 Inter-trip Scheme for SPS The tripping details for the month of November 2012 as furnished by the constituents are at Annexure – LVI.

11.4 Protection healthiness certification

• SRLDC also stated that reports in respect of the Monthly Declaration of availability

& Healthiness of various protection / defense mechanism were awaited from most

of the utilities.

• Karnataka suggested that protection healthiness certification issue needed to be

discussed and dealt with at PCC Meeting.

• MS i/c requested that the relevant details be submitted in the monthly OCC

meetings, since PCC met only once in about three months.

12. Loss of generation/ Frequency Response Characteristic

a) SRLDC stated that Loss of generation due to coal shortage /technical problems

needed to be furnished for onward transmission to NLDC by 10 00 hrs on a daily

basis. Further split-up details of Non Conventional Energy Sources generation for

Solar, biomass, wind, & small hydel in monthly data should be provided.

b) SRLDC also presented the Frequency Response Characteristic Calculation in

Southern Region during events of unit tripping and consequent generation loss. (Annexure-LVII).


13. Maintenance/shutdown: carried out

a) Generating Stations Details of generating units under shut down (forced as well as planned) during

the month of November - 2012 are enclosed as Annexure - LVIII.

b) Transmission lines and ICTs The planned maintenance of elements carried out by PGCIL/NLC during the

month of November - 2012 is furnished at Annexure – LIX.

14. Maintenance/shutdowns: forthcoming

a) Generating Stations b) Transmission lines and ICTs

The shutdown of ISTS elements approved in the OCC meeting is furnished in Annexure – LX. 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.

c) The following was noted during deliberations :

i. SRLDC stressed that shutdowns/outages as approved by the OCC forum

only could be allowed. Further the constituents needed to adhere to the

approved dates of the element outages.

ii. AP suggested that in future, details of proposed shutdown of PGCIL elements

be made available to them at least 2/3 days in advance of the OCC Meeting

through FAX/ e mail.

iii. OCC forum suggested to PGCIL that the stringing works of Nellore PS –

Gooty new line (crossing Vijayawada – Nellore D/C) be carried through hot-

line techniques. PGCIL stated that very limited gangs for this purpose were

available in the country and hence it may be difficult to obtain their services.

However attempt would be made to carry out the works through hot line

method as suggested by the OCC.

iv. NTPC Talcher requested for priority of its LTA (Long Term Access) over other

LTAs so that none of its units would have to shut down during the shutdown

of HVDC Poles. SRLDC replied that all efforts would be made to give

maximum possible schedule to the NTPC Talcher units. However any


commitment regarding priority etc would not be possible. Generation

scheduling of units would be based on prevalent system conditions such as

line loadings of the grid, sensitivity etc at the time of shutdown of the

elements. MS i/c also noted that any commitment in advance to NTPC

regarding scheduling may not be feasible, since a lot depended on the grid

conditions such as line loadings etc. However, SRLDC instructions needed to

be adhered to in the interest of maintenance of grid security.

15. Review of Performance of ULDC Scheme

a) Status of pending field inputs

i. In the Meeting, SRLDC presented the status of data, voice and internet communications and the same is furnished in Annexure – LXI.

ii. SRLDC also informed about the status of pending field inputs (Annexure – LXII).

iii. In the meeting, it was noted that there was no data being received from Jindal at

SRLDC. KPTCL said that due to RTU problem it could not be sent and assured

the OCC forum that effort had been taken to fix the problem and replacing the

RTU. SRLDC stated that voice hot line facility to NTECL Vallur similar to NTPC

Simhadri should be made available. It was also noted that there was no stand by

data channel at NTECL Vallur.

iv. It was noted that Kayathar 110 kV substation had been equipped with

synchronizing facility.

b) Earlier Deliberations:

i. In the 76th OCC meeting, with regard to pending field inputs in respect of NTPC

Talcher, it was noted that a Meeting in this regard with participation from NTPC,

POWERGRID, SRLDC and SRPC had been held on 17.09.2012 at Talcher. It

was also noted that in the recent TCC/SRPC Meetings SRLDC had intimated

that as per recent orders of Hon’ble CERC in respect of Petition No.

178/MP/2011, all users were required to submit information by 31st October

regarding the action plan for establishment of communication system for existing

system, time schedule etc. NLDC was to submit a report by 10th November 2012

about the status of implementation of telemetry system.


ii. In the 77th OCC Meeting it had been noted by NTPC that they are yet to receive

any response from ERTS II. ER ULDC needed to make necessary modifications

in the existing RTU.

16. SRLDC informed that the Second System Operator Exam was to be held on 16.12.2012.

17. Vote of Thanks

Member Secretary i/c, SRPC thanked all the Members for their active participation in the

Meeting.

18. Date & Venue of the Next Meeting

The schedule for the next Meeting of OCC is as follows:

Meeting : 79th OCC of SRPC

Date : 10.01.2013 (Thursday) Time : 10: 30 Hours Venue : Conference Hall, SRPC Bangalore

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southern regional power committee, bangalore · declared quantum for aufr & df/dt relief and...

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