Indian Electricity Grid Code

2

Contents

1. General

2. Role of various organisations and their linkages

3. Planning code for Inter State Transmission

4. Connection Code

5. Operating Code

6. Scheduling and Despatch Code

7. Miscellaneous

1. General

4

Introduction

To plan, develop, operate & maintain National/Regional Grid

Power System • Documentation of the principles which define relationship between various users •Facilitation of optimal operation•Facilitation power markets and ancillary services • Facilitation renewable energy sources

IEGC

RulesGuidelinesStandards

Utilities

connected with / using

for

ISTS

5

Compliance Oversight (1.5)

CERC

Repeated Violation/Persistent

Non Compliance

RLDC

Report

RPC ConsensusReport issues

not sorted

suo-motto

Action

6

Compliance Oversight (1.5)

CERC

Non Compliance by

NLDC, RLDC, SLDC, RPC

or any other person

Action

Report by any person

through petition

2. Role of Various Organizations and their

linkages NLDC, RLDC, RPC, CTU, CEA,

SLDC & STU

8

Role of NLDC (2.2)

RLDC

Inter Regional Links

Supervision

• Economy and Efficiency of National Grid• Monitoring of operations and grid security of National Grid• Restoration of synchronous operation of National Grid• Trans-national exchange of power• Feedback to CEA & CTU for national Grid Planning• Dissemination of information• Levy and collection of fee and charges - CERC• Disse

NLDC

Supervision & control

RPC for regional outage Plan

Coordinate

Coordinate

Accounting

9

Role of RLDC (2.3)

• Real time operation , control & contingency analysis

• Generation scheduling/ re-scheduling• Restoration • Metering & data collection • Compiling & furnishing of operation data• Operation of Regional UI pool Account.

Reactive energy account and Congestion charge account

• Operation of ancillary services

RLDC

Exclusive functions

10

Role of RLDC (2.3)

Functions •optimum scheduling and despatch of electricity•Monitor grid operation•Keep accounts of electricity transmitted• Exercise Supervision and control over the ISTS• Real time operations• Licensee

• Generating company• Generating station / Sub-

stations• any other concerned person

SLDC

Central State

DirectionsComply the directions

Apex body

for integrated operation

For ST Open

Access- Nodal

Agency

RLDC

11

Role of RPC (2.4 )

• Facilitate the stable and smooth operations of the system • Functions:

– regional level operation analysis– facilitate inter-state/inter-regional transfer of power– facilitate planning of inter-state/intrastate transmission system– coordinate maintenance of generating units– coordinate maintenance of transmission system– protection studies– Planning for maintaining proper voltages– Consensus on issues related to economy and efficiency

RPC

RLDC/SLDC/CTU/

STU/ Users

DecisionsMS SRPC shall certify Availability of transmission system

Prepare Regional Energy Account, Weekly UI, Reactive & Congestion charge account

12

Role of CTU (2.5)

• to undertake transmission of electricity through ISTS

• to ensure development of an efficient, co-ordinated and economical ISTS

CTU

RLDC

shall operate

ISTS lines

CTU/to provide non-discriminatory Open Access

– Will not engage in trading and generation

– For LTOA & MTOA nodal agency

Planning

STU

Central Govt.

State2

State1

State Govt.

Generating Companies

CEA

RPC

Licensees

13

Role of CEA (2.6)

CEA(Central Electricity Authority)

• will formulate short-term and perspective plans for transmission system

•specify technical standards for construction of electrical plants, electric lines and connectivity to the grid

•specify safety requirements for construction, operation and maintenance of electrical plants and electrical lines

•specify grid standards for operation and maintenance of transmission lines

•specify conditions for SEMs

•Promote and assist timely completion of schemes

•To collect and record electrical data- cost, efficiency

•To carry out investigation ( Electrical system)

• Shall Prepare National Electricity Plan (NEP)

14

Role of SLDC (2.6)

SLDC – Apex body in a State

Power System

State

• Optimum scheduling and despatch

• Monitor grid operations

• Keep accounts of electricity transmitted

• Activities of Real-time operation

• exercise supervision and control

RLDC

Directions

Ensure compliance

Directions and exercise

supervision and control

Licensee, generating company,

generating station, sub-station

and any other concerned person

15

Role of STU (2.8)

• to undertake transmission of electricity through intra-state transmission system

• to ensure development of an efficient, co-ordinated and economical intra-state transmission system

STU

SLDC

shall operate

Intra-state transmission system

STU/to provide non-discriminatory Open Access

Planning

CTUState Govt.

Generating Companies

CEA

RPC

Licensees

16

Role of STU (2.8)

• Energy transfer• Efficient• Economical

STU

SLDC

shall operate

Provide non-discriminatory open access

Intra-state transmission system

• CTU•State Government

•Generartors•RPCs•CEA

•Licencees

• Planning• Coordination

3. Planning Code for Inter-state Transmission

• Introduction• Objective• Scope• Planning Philosophy• Planning Criterion• Planning Data• Implementation of Transmission Plan

18

Introduction

Intra-State Inter-state

CEA

Intra-State

STU CTU

Transmission schemes for planning and coordination

STU

Transmission schemesfor planning and coordination

19

Scope of planning code (3.3)

ISTS

SEBsSTU

Licensees

ISGS GC

IPP

CTU

Generation/Transmission of energy to/from ISTS

Connected to/using/developing ISTS

• specify principles,• specify procedures •specify criteria•promote coordination•information exchange

Objective

20

Planning Philosophy (3.4)

CTU• Identification of major

inter state/regional lines including system strengthening schemes

• Planning schemes shall also consider:CEA’s: Long-term perspective plan Electric Power Survey of India report Transmission Planning Criteria and

guidelines RPC Feedback NLDC/RLDC/SLDC feedback CERC Regulations Renewable capacity addition (MNRES)

Annual plan (5 year forward term)

CEA

Long-term plan (10-15 years)

• inter/intra state transmission system

• continuously updated to reflectload projections and generation scenarios

• NEP

• Avoid congestion

21

Planning philosophy (contd...)

• System strengthening schemes by CTU:– shall be done in consultation with CEA’s

Standing Committee for Transmission System Planning:

• Planning– On the basis of PPA– No PPA/ no consensus – CTU may approach CERC in

accordance with CERC (Grant of Regulatory approval for Capital Investment to CTU for execution of ISTS)

• Planning data:– submission by STUs/Users to CTU:

22

Planning philosophy (contd...)

• Voltage management by:– capacitors, reactors, SVC and FACTs

– similar exercise by STU

• STU shall plan to evacuate power from ISTS • ISTS & intra-state transmission systems are

complementary & interdependent• If LTA Applications require strengthening of

intra-state transmission system – applicant shall coordinate with STU

23

Planning Criterion (3.5)Planning criterion ISTS’s security philosophyCEA guidelines

a) Without load shedding or rescheduling of generation, ISTS shallwithstand and secure against the following outages:– a 132 KV D/C line, a 220 KV /DC line, – a 400 KV S/C line, 765 KV S/C line– single Inter-Connecting Transformer (ICT )– one pole of HVDC Bi-pole– Outage of 765 kV S/C line

Without load shedding but could be with rescheduling of generation,ISTS shall withstand and secure against the following outages:– a 400 KV D/C line– a 400 KV S/C line with TCSC– both pole of HVDC Bi-pole line– Outage of 765 KV S/C line with series compensation

24

Planning Criterion (3.5)

b) ISTS shall withstand the loss of most severe single system infeed without loss of stability

c) Any one of the events defined above should not cause:– loss of supply– prolonged operation of frequency below and

above limits– unacceptable high or low voltage– system instability– unacceptable overloading of ISTS elements

25

Planning Data & Implementation

d)All S/S (132 kV & above) shall have at least two transformers

e)CTU will carry out reactive power compensation requirement of ISTS & at ISGS’ switchyard

f)SPS may be planned by NLDC/RLDC in consultation with CEA, CTU, RPC & Regional entities – for enhancing transfer capability or to take care of additional contingencies

26

Planning Data & Implementation

• Planning Data (3.6)– As per CERC (Grant of Connectivity, LTA and MTOA

in ISTS and related matters) Regulations 2009

• Implementation of Transmission Plan (3.7)– Actual program of implementation of transmission

lines, ICTs, reactors/capacitors and other transmission elements as per CERC (Grant of Connectivity, LTA and MTOA in ISTS and related matters) Regulations 2009

4. Connection Code

Minimum technical &

design criteria

OBJECTIVE• Ensure the safe operation, integrity and reliability of the grid •Non-discriminatory•New/modified connection not suffer or impose unacceptable effects•In advance knowledge about Connectivity

ISTS

SCOPE

CTUSTU

Users connected to ISTS or seeking connection to ISTS

Comply with CEA( Technical

Standards for connectivity to

the Grid) 2007

28

Procedure for connection (4.4)

• User seeking new/modified connection:– Shall submit an application on standard format

in accordance with CERC (Grant of Connectivity, LTA and MTOA in ISTS and related matters) Regulations 2009

– CTU shall process as per above regulations

29

4.5 Connection Agreement

–Connection agreement would be signed by the applicant in accordance with CERC (Grant of Connectivity, LTA and MTOA in ISTS and related matters) Regulations 2009

–Connection agreement would be signed by the applicant in accordance with CERC (Grant of Connectivity, LTA and MTOA in ISTS and related matters) Regulations 2009

30

Reactive Power Compensation 4.6.1

– by /STUs and Users in the low voltage systems close to the load points therby avoiding exchange of reactive power to/ from the ISTS

– Already connected shall provide additional reactive compensation as per the quantum and time frame decided by the RPC in consultation with RLDC.

– Installation and healthiness would be monitored by RPC

31

Data and Communication Facilities (4.6.2)– reliable and efficient speech and

communication system to be provided – Users/STU/CTU shall provide systems to

telemeter power system parameters• Flow

• Voltage

• Status of switches

• Status of transformer taps

– Associated communication system to facilitate data flow up to appropriate data collection point on CTU’s system as specified by CTU in the Connection Agreement

32

System Recording Instruments (4.6.3)– Data Acquisition System/Disturbance

Recorder/Event Logging facilties/Fault Locator (including time synchronization equipment ) shall be provided and always kept in working condition

Responsibility for safety (4.6.4)– CEA (Technical Standards for connectivity to the Grid),

Regulations 2007

– CERC (Grant of Connectivity, LTA and MTOA in ISTS and related matters) Regulations 2009

– CEA (Safety Requirements for construction, operation and maintenance of electrical and electric lines) Regulations, 2008

33

International Connections to ISTS (4.7)

– By CTU in consultation with CEA and MOP

Schedule of assets of Regional Grid (4.8)

– CTU and other transmission licensees shall submit by 30th Sep a schedule of transmission assets as on 31st March indicating ownership on which RLDC has operational control and responsibility.

34

5. Operating Code

35

Operating philosophy (5.1)

• objective of the integrated operation:– enhance overall operational reliability and economy

– Cooperate and adopt Good Utility Practice

• NLDC:– overall operation of National/Inter-Regional Grid

– develop/maintain detailed internal operating procedures for national grid

• RLDC:– overall operation of Regional Grid

– develop/maintain detailed internal operating procedures for regional grid

36

Operating philosophy (5.1)

• SLDC:– develop/maintain detailed internal operating procedures

for State grid

• All licensee, generating company, generating station and any other concerned person:– comply with directions of RLDC/SLDC

e) round-the clock manning by qualified and trained personnel of:– control rooms of NLDC, RLDC, SLDC, Power Plant,

Sub Stations (132 kV & above)

– control centres of all regional constituents

37

System Security Aspects (5.2)• Synchronism:

– all Users, CTU & STU – operate their power systems/stations in an integrated

manner

• No deliberate isolation of part of the grid:– except under emergency– safety of human/equipment– when instructed by RLDC– restoration to be supervised by RLDC in coordination

with NLDC/SLDC

38

System Security Aspects (5.2)• Important elements list at RLDC:

– not removed without RLDC’s consent or prior consent– when specifically instructed– list of important elements to be prepared and shall be

put on website of NLDC/RLDC/SLDC– emergency removal intimated to RLDC– tripping, reason, likely time of restoration intimated to

RLDC say within 10 minutes– Important elements tripping to be informed to NLDC

by RLDC– Prolonged outage ------ sub-optimal operation----

monitored by RLDC------report to RPC-------- finalise action plan for restoration

39

Restricted Governor Action (5.2(f))• Thermal generating > 200 MW and hydro units > 10

MW on RGMO wef 01.08.2010• Gas Units, Combined Cycle, wind, solar & nuclear

exempted till CERC reviews• When frequency stabilise at 50.0 Hz FGMO would be

intoduced• RGMO

– For Frequency < 50.2 Hz no reduction in generation when frequency rises

– Any fall in frequency generation should increase by 5% limited to 105% of MCR (thermal), 110% MCR (Hydro)

– After increase in generation, the unit mey ramp back to original level at a rate of 1% per minute

– At Frequency < 49.7 Hz ramp up could be at higher rate – governors: 3% - 6% droop– any exception: reason & duration to RLDC

40

System Security Aspects 5.2 (s)

Voltage- (kV rms)

Nominal Maximum Minimum

765 800 728

400 420 380

220 245 198

132 145 122

110 121 99

66 72 60

33 36 30

41

DEMAND ESTIMATION FOR OPERARTIONAL PURPOSES

on-line estimation

for daily operationa

l use

historical data and weather forecast

Daily/Weekly/Monthly

Demand Estimation – Active and reactive

power

By 01.01.2011 – online estimation of demand for each 15 min block

Inform to RLDC/

RPCWind Energy Forecast

ATC/TTC

42

Demand Management(5.4)

• SLDCs shall control demand in the event of:• insufficient generating capacity/inadequate external transfer• breakdown/congestion problems

• Demand disconnection– frequency:

• below 49.7 Hz: shall initiate action to restrict their net drawal• below 49.5 Hz: requisite load shedding

– Each User/STU/SLDC shall formulate contingency procedures and make arrangements. Contingency Procedure to be regularly updated and monitored by SLDC/RLDC

– SLDC through respective SEBs/Discoms shall formulate and implement state-of-the-art demand management schemes- roatational load shedding/demand response (which may include lower tariff for interruptible load) etc. SLDC to furnish periodic report to CERC.

43

Demand Management(5.4.2(e)(f)(g)(h))

• Interruptible load in four groups:• Scheduled load shedding/power cuts• Unscheduled load shedding• UFR/df/dt loads• SPS loads

• RLDC may direct to decrease drawal in contingency---SLDCto send compliance report

• SLDC may direct SEB/Discom/bulk consumer to curtail drawal and monitor

• RLDC shall devise standard, instantaneous, message formats• Congestion – requisite load shedding or generation backing down .

Implementation as per CERC ( Measures to relieve congestion in real time operation), Regulations, 2009

44

Periodic Reports (5.5)

• weekly report by NLDC (put on website):

– Performance of national/integrated grid

• daily report by RLDC (put on website):

– Performance of national/integrated grid

– Wind power injection• quarterly report by RLDC :

– system constraints, reasons for not meeting the requirements, security standards & quality of service

– actions taken by different persons– persons responsible for causing the

constraints

• weekly report by RLDC (put on website):

– Frequency and voltage profiles– Major generation & transmission

outages– Transmission constraints– Instances of persistent/significant

non-compliance of IEGC– Instances of congestion– Instance of inordinate delay in

restoration – Non-compliance of instructions of

SLDCs by SEB/Discom• RLDC shall provide

information/report to RPC for smooth operation of ISTS

45

Operational Liaison (5.6)

• Introductiona) requirements for the exchange of information in

relation to Operations/Events on the total grid system which have had or will have an effect on:

• National grid• the regional grid• the ISTS in the region• the system of a User/STU(the above generally relates to notifying of what is expected to

happen or has happened and not the reasons why)

b) Operational liaison function is a mandatory built-in hierarchical function of the NLDC/RLDC/SLDC/Users to facilitate quick transfer of information to operational staff

46

Procedure for Operational Liaison• Procedure for Operational Liaison

a) Operations and event on the regional grid• before carrying out any operation, RLDC will inform User/SLDC/CTU whose

system will be affected• immediately following an event, RLDC will inform the User/SLDC/CTU with

details of what happened but not the reasons why• RLDC to NLDC if other region is going to be affected• immediately following an event, NLDC would keep all RLDCs informed

b) Operations and events on a User/STU system• before carrying out any operation that will affect regional grid, constituent

shall inform RLDC with details• RLDC to NLDC if other region is going to be affected• immediately following an event, the User/SLDC shall inform RLDC with

details but not the reasons why• immediately following an event, NLDC would keep all RLDCs informed

• Prolonged Forced outages – monitored at RPC level. RPC shall send a monthly report to CERC

47

Outage Planning (5.7)

Introductiona) procedures for preparation of outage schedules for the

elements of the National/Regional in a coordinated and optimal manner and the balance of generation and demand

b) generation output and transmission system should be adequate after taking outages into account to achieve security standards

c) annual outage plan for the financial year shall be prepared by RPC Secretariat and reviewed during the quaterly and monthly basis. ROR, wind & solar power to be extracted to maximum

48

Outage Planning Process

MarJanNov next financial year

proposed outage programmes by all concerned (30th Nov)

Dec

draft outage programme by RPC Secretariat (31st Dec)

final outage programme by (31st Jan)

Feb

Review by RPC Secretariat: adjustments made wherever found to be necessary in coordination with all parties concerned

monthly review quarterly review

49

Outage Planning (5.7.4)• In consultation with NLDC/RLDC• In Emergency – RLDCs may conduct studies before

clearance• NLDC/RLDC are authorized to defer

- grid disturbance- system isolation- partial black out in a state- any other critical event

• Latest detailed outage plan – updated • Each user, CTU and STU shall obtain one final approval

from RLDC• RPC shall submit quarterly, half yearly reports to CERC

indicating deviations

50

Recovery Procedures (5.8)

Detailed plans/procedures for restoration of partial/total blackout regional grid

consultations

RLDC

Concerned Constituents

RPC secretariat

develops

reviewed/updated annually

Detailed plans/procedures for restoration of partial/total blackout

develop

reviewed/updated annually

• Mock trials once every 6 months

•DG sets to be tested on weekly basis- quarterly report to be sent to RLDC

51

Recovery Procedures (contd...)• List of the following shall be available with

NLDC/RLDC/SLDC:– generating stations with black start facility– inter-state/regional ties– synchronising points – essential loads to be restored on priority

• During restoration following blackout, RLDC authorized to operate the grid with reduced security standards for v & f

• all communications channels for restoration shall be used for operational communications only till grid normalcy is restored

52

Event Information (5.9)

• Introduction– reporting procedures in respect of events to all Users,

STU,CTU RPC secretariat, NLDC/RLDC/ SLDC

• Responsibility– RLDC/SLDC shall be responsible for reporting events

to the Users/SLDC/ STU/CTU RPC secretariat/ NLDC /RLDC

– Users/ STU/CTU /SLDC shall be responsible for collection and reporting all necessary data to NLDC/RLDC and RPC secretariat for monitoring, reporting, and event analysis

53

Reportable events (5.9.5)

i Violation of security Standards

ii Grid indiscipline

iii Non-Compliance of RLDC’s instruction

iv System islanding/ system split

v Regional black out/partial system black out

vi Protection failure

vii Power system instability

viii Tripping of any element

ix Sudden load Reduction

54

Reporting Procedure

RLDCUsers/STU/CTU/SLDC

written report of events

weekly written report of events

• Form of written reports:

NLDC

i) Time and date vi) Duration of interruption

ii) Location vii) Recording System informations

iii) Plant or equipment directly involved

viii) Sequence of trippings with time

iv) Description and cause of event ix) Remedial Measures

v) Antecedent Condition

55

6. Scheduling & Despatch Code

a) demarcation of responsibilities

b) procedure for scheduling & despatch

c) Reactive power and voltage control mechanism

d) complementary commercial mechanism (Annexure-I)

OBJECTIVE•Procedure for submission of Capability declaration•Procedure for submission of requistion/ drawal schedule by regional entities•Real time despatch/drawal instructions•Rescheduling• Commercial arrangement for UI/Reactive• Scheduling of wind/solar on 3 hourly basis•Appropriate Metering

Discoms

SCOPE

Power Exchanges ISGS

SEBs/STUsOther

concerned

Wind/Solar generators

NLDC RLDC SLDC

57

Demarcation of responsibilities (6.4)Role of RLDC

RLDC

Scheduling of CGS (Except where full share is allocated to host state)

Scheduling of UMPP

Scheduling of

GS connect

ed to ISTS

Scheduling of GS

connected both to

ISTS and state grid and home

state is less then 50%

58

Demarcation of responsibilities (6.4.4)SLDC

SLDC

Permitting Open Access

Regulating net drawal

Scheduling and despatching

Scheduling drawal from

ISGS

Demand Regulation

6.4.8 Demand Estimation in

coordination with STU/Discoms

59

Demarcation of responsibilities (6.4.6/7)

System of each regional entity shall be operated as notional control area

Scheduled drawal + Bilaterals on day ahead basis

Regional entity would regulate its own generation and load so that drawals are close to schedules

Regional entity would Endeavour for UI=0 at F<49.7 Hz.At F< 49.5 Hz ,automatic demand management scheme/manual demand disconnection

60

Regional Entities Agreements

ISGS project2

Joint/bilateral agreements for

–State’s share in ISGS projects

–scheduled drawal pattern

–tariffs

–payment terms

ISGS project1

ISGS projet3

State3

State4

State5

State2State1

RLDC RPC

CTU Long Term, MTOA RLDC/SLDC

61

6.4.9 Role of ISGS/Generating Station

ISGS

Generate as per despatch schedule advised to them

by RLDC

Deviation from

Schedule UIProper

Operation and

Maintenance

When F>50.2 ,

backdown generation

When F<49.7 , maximize generation

Planned Outages OCC of RPC

DC during Peak Hours

> Other Hours

Declare DC Faithfully

Penalty : Capacity Charges reduced

62

Role of CTU

CTUInstall SEMs

CEA (Installation and operation of Meters ) Regulations

Weekly Readings

Constituents where

SEMs are

located

63

Demarcation of responsibilities Role of RLDC

RLDC

Periodically review UI

Gaming by ISGS

15 min drawal

and injection

MS RPC

Report

105 % in one block of 15 minutes and 101% over a day no gaming

64

Role of RPC

RPCOutage

Planning

REA, UI, Var

Accounting

65

Role of NLDC

NLDC

Trans-National Exhange of

PowerScheduling on Inter Regional

Links .

Energy accounting

on IR Links- with RLDC

HVDC Settings

Scheduling of Inter-Regional

Power Exchanges

Collective Transaction Scheduling

66

Scheduling & Despatch Procedure (6.5)

• List of ISGSs and beneficiaries– all ISGS whose output is shared by more than state

shall be listed on RLDC and SLDC websites– the station capacities and allocated/contracted shares

of different beneficiaries shall also be listed out

• State’ entitlement:– Thermal ISGS:

(foreseen ex-power plant MW capability for the day) X(state’s share in the station’s capacity)

– Hydro ISGS:(MWH generation capacity for the day) X

(state’s share in the station’s capacity)

67

Preparing final schedule

12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1noon

ISGS

SLDC

Despatch schedule

net Drawal

schedule

revision

revisionstation-wise MW/MWH capability

station-wise W/MWH entitlement

required Drawal

schedule

AM PM

RLDC

Despatch schedule starts

Drawalschedule starts

finalDespatch schedule

final Drawal

schedule

Scheduling of Collective Transaction 6.5.5

68

Power Exchanges

NLDC

SLDC RLDC

1. List of Interfaces,

Control areas 2. Interchanges on Interfaces, Control

areas

3. Check for Congestion , reworked as per CERC

directive

4. Consultation

6. Individual

Transactions

7. Schedule individual transaction

5.Schedule at respective

periphery

69

Revision of schedules during the day• any State may revise:

– drawal schedule from any/all ISGS within their entitlementsto be effective from 6h time block)

• an ISGS may revise:– capability on account of forced outage. (to be effective from 4th

time block)– Revision (to be effective from 6h time block)

• RLDC can revise: – In the interest of better system operation (to be effective from 4th

time block)– Shall formulate procedure for meeting contingency

70

Other Contingencies

• In the event of bottleneck in evacuation of power, RLDC may revise the schedules which will be effective from 4th time block and for 1-3 time blocks schedules would deemed to have been replaced by actual.

• Similarly for entire period of grid disturbance, schedules will be replaced by actual

• No revision – if change in previous schedule/capability is less than 2%.

71

Other Contingencies

• For every change in generation schedule there would be corresponding change in drawal schedule

• Procedure for recording the communication regarding changes in schedules taking into account to be developed by CTU

72

Final schedule & Documentation• RLDC’s final implemented schedule:

– shall be the datum for commercial accounting– shall be open for 5 days for verification/correction

• RLDC shall properly document the following:– station-wise foreseen ex-power plant capabilities

advised by the generating stations– the drawal schedules advised by beneficiaries– all schedules issued by RLDC– all revisions/updating of the schedules

73

Reactive Power & Voltage Control (6.6)• VAR Charges under Low

Voltage• VAR Charges under High

voltage

Beneficiary1

Voltage: < 97%

Pool Account

VAR charges

EHV grid

Beneficiary2

Q Q

Beneficiary1

Voltage: > 103%

Pool Account

VAR charges

EHV grid

Beneficiary2

Q Q

74

VAR charges settlement• No VAR charges for its own lines emanating directly from ISGS

• VAR charges at the nominal paise/KVArh rate as may be specified by CERC and will be between beneficiaries and POOL (Present rate is 10.0 p/kvarh with escalation of 0.5 p/kvarh every year)

• RLDC may direct Regional entity to curtail VAR drawal/injection for safety and security of grid or safety of equipment

• Beneficiaries to minimise injection/drawal of VAR if voltage goes beyond + 5%.

• ICT taps may changed as per regional entity request to RLDC

• Tap changing (400/220 kV)and switching in/out of line reactors (400kV) shall be carried out as per RLDC instruction.

75

Annexure-1 (6.1 d) Complementary Commercial Mechanisms

76

Capacity charge + Energy charge

ISGS

beneficiary1

beneficiary2

UI

Capacity charge + Energy charge

UI

Generation Cost

UI Settlement

SystemUI

Full reimbursement

for generation as per the

generation schedule

77

Weekly bills & penalty (12, 13, 14)

RLDCConstituents

UI Settlement

System

Pool Account

UI bills UI payment

VAR payment

• payment within 10 days from date of billing

• simple interest @ 0.04% per day to constituent for delayed payment beyond 12 days.

RPC VAR bills

monthly payment status

CERCpayment defaults

78

Regional Energy AccountingSun

15-minute block SEM readings for a week

RLDCConstituents

Weekly raw SEM data

Weekly UI and VAR Account

ISTSConnections

MonTueWedThuFriSatSunMonTueWedThuFriSatSunMonTue

Monthly (6th):

REA

RLDC to tabulate UI account and REA in RPC’s CC meeting on a quarterrly basis for audit by the later.

Complementary Commercial Mechanism

• Money left in VAR account shall be utilized for training of SLDC operators and other similar purposes

Thank you!