Download - Indian Electricity Grid Code
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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
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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
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Compliance Oversight (1.5)
CERC
Repeated Violation/Persistent
Non Compliance
RLDC
Report
RPC ConsensusReport issues
not sorted
suo-motto
Action
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Compliance Oversight (1.5)
CERC
Non Compliance by
NLDC, RLDC, SLDC, RPC
or any other person
Action
Report by any person
through petition
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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
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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
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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
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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
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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
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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)
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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
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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
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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
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Introduction
Intra-State Inter-state
CEA
Intra-State
STU CTU
Transmission schemes for planning and coordination
STU
Transmission schemesfor planning and coordination
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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
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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
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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:
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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.
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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
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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
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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
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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
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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
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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
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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
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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.
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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%
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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%.
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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
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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.
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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
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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
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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