Indian Power System Peculiarities & Solutions S K Soonee Executive Director NRLDC.

Indian Power System Indian Power System Peculiarities & SolutionsPeculiarities & Solutions

S K Soonee

Executive Director

NRLDC

Landmarks … Landmarks …

Pre – Independence PeriodPre – Independence Period– First Hydel Project (Darjeeling) – 1897First Hydel Project (Darjeeling) – 1897– First Steam Plant (1000 KW) Calcutta – 1899First Steam Plant (1000 KW) Calcutta – 1899– Survey of Hydro Power Potential – 1919-1921Survey of Hydro Power Potential – 1919-1921– Generation during World War – II – 1140Generation during World War – II – 1140– Generation at the time of Independence – 1349 Generation at the time of Independence – 1349

MWMW

Phenomenal expansion since IndependencePhenomenal expansion since Independence

Generation : 1349 MW Generation : 1349 MW 112,058 MW 112,058 MW (in 1947)(in 1947) (in 2004) (in 2004)

Grid :Grid :

Local grid – at the time of Independence.Local grid – at the time of Independence.

State Grids – emerged in 1960s.State Grids – emerged in 1960s.

Regional Grids – in 1970s.Regional Grids – in 1970s.

Five Regional Grids – Five Regional Grids – Northern, Western, Southern,Northern, Western, Southern, Eastern & North-easternEastern & North-eastern

National Grid – All Five Regions Interconnected (2002)National Grid – All Five Regions Interconnected (2002)

Formation Of Formation Of Central GridCentral Grid by Synchronizing by Synchronizing North Eastern - Eastern – Western Grids North Eastern - Eastern – Western Grids

(2003)(2003)

Indian Power Grid – its EvolutionIndian Power Grid – its Evolution

INDIAN POWER SECTORINDIAN POWER SECTOR

India is a FEDERAL countryIndia is a FEDERAL country

Electricity a concurrent subject – Both Central and Electricity a concurrent subject – Both Central and State Govts. responsible for its developmentState Govts. responsible for its development

Multiplicity of players Multiplicity of players

Roles are demarcatedRoles are demarcated

Growth of installed capacity for Growth of installed capacity for electricity in Indiaelectricity in India

0

20000

40000

60000

80000

100000

120000

1990

-91

1991

-92

1992

-93

1993

-94

1994

-95

1995

-96

1996

-97

1997

-98

1998

-99

1999

-200

0

2000

-200

1

2003

-200

4

in MW

Regional Grids Of India

Inter Regional LinksInter Regional Links

Present IR CapacityPresent IR Capacity= 8,500 MW= 8,500 MW

By the year 2012By the year 2012= 30,000 MW= 30,000 MW

500 MW500 MW

1000MW1000MW

2000MW2000MW

500 MW500 MW

500 MW500 MW

1200 MW1200 MW

ROURKELA

RAIPUR HIRMA

TALCHER

JAIPUR

NER

ERWR

NR

SR

B'SHARIF

ALLAHABAD

SIPAT

GAZUWAKA

JEYPORECHANDRAPUR

SINGRAULI

VINDHYA-

1000MW

500MW

LUCKNOW

CHICKEN NECK

KRISHNA

TEESTA

MISA

KATHAL-GURI

LEGEND

765 KV LINES

400 KV LINES

HVDC B/B

HVDC BIPOLE

EXISTING/ X PLAN

ZERDA

HISSAR

BONGAIGAON

DEVELOPMENT OF NATIONAL GRID

KOLHAPUR

NARENDRA

KAIGA

MANGALORE

PONDA

IX PLAN

MARIANI

N.K.

KAHALGAON

RANGANADI

SEONI

CHEGAON

BHANDARA

DEHGAM

KARAD

LONIKAND

VAPI

GANDHAR/

TALA

BANGLA

BALLABGARH A'PUR(DELHI RING)

BANGALORE

KOZHIKODE

COCHIN

KAYAMKULAM

TRIVANDRUM

PUGALUR

KAYATHAR

KARAIKUDI

CUDDALORE

SOUTH CHENNAI

KRISHNAPATNAM

CHITTOOR

VIJAYAWADA

SINGARPET

PIPAVAV

LIMBDI

KISHENPUR

DULHASTI

WAGOORA

MOGA

URI

BHUTAN

RAMAGUNDAM

RAVI

JULLANDHAR

DESH

NAGAR

VARANASI

/UNNAO

M'BAD

PURNEA

KORBA

NAGDA

SILIGURI/BIRPARA

TEHRI

MEERUT

BHIWADI

BINA SATNA

MALANPURSHIROHI

KAWAS

PHASE - II(By 2007)

SIRSI

CHAL

JETPURAMRELI

BOISARPADGHE

DHABOL

KOYNA

/BARH

G'PUR

HOSUR

ROURKELA

RAIPUR HIRMA

TALCHER

JAIPUR

NER

ERWR

NR

SR

B'SHARIF

ALLAHABAD

SIPAT

GAZUWAKA

JEYPORECHANDRAPUR

SINGRAULI

VINDHYA-

1000MW

500MW

LUCKNOW

DIHANG

CHICKEN NECK

KRISHNA

TEESTA

TIPAIMUKH

BADARPUR

MISA

DAMWE

KATHAL-GURI

LEGEND

765 KV LINES

400 KV LINES

HVDC B/B

HVDC BIPOLE

EXISTING/ X PLAN XI PLAN

ZERDA

HISSAR

BONGAIGAON

DEVELOPMENT OF NATIONAL GRID

KOLHAPUR

NARENDRA

KAIGA

MANGALORE

PONDA

IX PLAN

MARIANI

N.K.

KAHALGAON

RANGANADI

SEONI

CHEGAON

BHANDARA

DEHGAM

KARAD

LONIKAND

VAPI

GANDHAR/

TALAARUN

BANGLA

BALLABGARH A'PUR(DELHI RING)

BANGALORE

KOZHIKODE

COCHIN

KAYAMKULAM

TRIVANDRUM

PUGALUR

KAYATHAR

KARAIKUDI

CUDDALORE

SOUTH CHENNAI

KRISHNAPATNAM

CHITTOOR

VIJAYAWADA

SINGARPET

PIPAVAV

LIMBDI

KISHENPUR

DULHASTI

WAGOORA

MOGA

URI

BHUTAN

RAMAGUNDAM

SATLUJRAVI

JULLANDHAR

DESH

NAGAR

VARANASI

/UNNAO

M'BAD

PURNEA

KORBA

NAGDA

SILIGURI/BIRPARA

PHASE - III

TEHRI

MEERUT

BHIWADI

BINA SATNA

MALANPURSHIROHI

KAWAS

AMRAVATI

AKOLA

(By 2012)

AGRA

SIRSI

CHAL

JETPURAMRELI

BOISARTARAPUR

PADGHE

DHABOL

KOYNA

/BARH

G'PUR

HOSUR

RTU RTU RTU

SUB LDC SUB LDC SUB LDC

SLDC SLDC SLDC

ERLDC

WRLDC NRLDC SRLDC

NERLDC

NLDC

23 Nos.

51 Nos.

1160Nos.

Unified Grid OperationUnified Grid Operation

5 Nos.

NationalLevel

RegionalLevel

State HQLevel

Group / Distt Level

Plant / Sub-Station Level

Regional Grid

State - A

State - B

State - C

CS - 1 MPPCS - 2

RLDCCoordinates

Control Areas

SEB’s Grid

Discom - A

Discom - B

Discom - C

STATE IPP

CENTRALSHARE

STATE GENR.

SLDCCoordinatesDirects

Control Areas

TRADER

Trading

Consumer

Trading

HierarchyHierarchy Policy and Administrative Policy and Administrative

issuesissuesGovt. (through Ministry of Power)Govt. (through Ministry of Power)

Power Sector PlanningPower Sector Planning Central Electricity Authority (CEA)Central Electricity Authority (CEA) A Central Govt bodyA Central Govt body Responsible for coordinated planningResponsible for coordinated planning Technical Advisor to Govt.Technical Advisor to Govt.

RegulationRegulation CERC at Center and SERC at State CERC at Center and SERC at State levellevel

Operation -NLDCOperation -NLDC

-RLDC-RLDC

-SLDC-SLDC

Under Implementation by Under Implementation by POWERGRIDPOWERGRID

Responsible for Regional Grid Responsible for Regional Grid OperationOperation

Responsible for State Grid OperationResponsible for State Grid Operation

GenerationGeneration DelicensedDelicensed

TransmissionTransmission Licensed activityLicensed activity Overall development of central sector transmission from Overall development of central sector transmission from

concept to commissioning and its operation entrusted to concept to commissioning and its operation entrusted to Central Transmission Utility (CTU- a statutory body Central Transmission Utility (CTU- a statutory body under GoI) , i.e POWERGRIDunder GoI) , i.e POWERGRID

Similarly, STU (- a statutory body under State Govt.) Similarly, STU (- a statutory body under State Govt.) responsible for State sector transmissionresponsible for State sector transmission

DistributionDistribution LicensedLicensed

TradingTrading LicensedLicensed

Grid Grid ManagementManagement

Entrusted to CTU (POWERGRID)Entrusted to CTU (POWERGRID) NLDC under implementationNLDC under implementation Operation of Regional Grids by RLDCs Operation of Regional Grids by RLDCs Operation of State Power System by SLDCs in Operation of State Power System by SLDCs in

association with RLDCsassociation with RLDCs

Generation, Transmission & DistributionGeneration, Transmission & Distribution

States were generally in the form of:States were generally in the form of:

1.Vertically Integrated Utilities having1.Vertically Integrated Utilities having

-- Own GenerationOwn Generation-- Own TransmissionOwn Transmission-- Own DistributionOwn Distribution

2.Having fixed shares in the Central Sector2.Having fixed shares in the Central Sector

3.Counting on Load-Generation Balance within 3.Counting on Load-Generation Balance within the Statethe State

Pre – Reforms Scenario

1. State regulatory commissions (SERCs) constituted

2. SERCs have issued tariff orders

3. States have unbundled their SEBs

4. States are in the process of privatising distribution

5. States have signed MoUs with the Ministry of Power

6. All around emphasis to provide 100% metering

Indian Power Sector Reforms

Indian Power Sector-DistributionIndian Power Sector-Distribution

Distribution originally with the State Electricity Boards (SEBs) with licenses given out for some areas to private.

After unbundling of SEBs, separate (DISCOMS) formed at state level. Privatisation of DISCOMS already done in two states viz. Delhi and Orissa.

Emphasis on metering, loss reduction at this level with the Central Govt. acting as a

catalyst through assistance under APDRP.

Defines responsibilities between Utilities, RLDCs and REBs

Defines scheduling mechanism for day ahead scheduling of Generation and Drawal

Specified frequency bands for operation of regional grids

Frequency stabilization through free governor mode of generating units

Defines charge for Reactive Energy drawal

Indian Electricity Grid CodeIndian Electricity Grid Code

Commercial MechanismCommercial Mechanism

A B TA B T

INDIAN POWER SECTORINDIAN POWER SECTOR

Components of inter-utility tariffComponents of inter-utility tariff(Pre – ABT Mechanism)(Pre – ABT Mechanism)

Fixed chargesFixed charges Interest on loansInterest on loans DepreciationDepreciation O & M chargesO & M charges Return on equityReturn on equity Interest on Working CapitalInterest on Working Capital

Energy charges (fuel cost)Energy charges (fuel cost) IncentivesIncentives Surcharge & other leviesSurcharge & other levies No charge for reactive energyNo charge for reactive energy

AVAILABILITY BASED TARIFFAVAILABILITY BASED TARIFF

(A)(A) CAPACITY CHARGECAPACITY CHARGE

(B)(B) ENERGY CHARGEENERGY CHARGE

(C)(C) ADJUSTMENT FOR DEVIATIONS ADJUSTMENT FOR DEVIATIONS

(U I CHARGE)(U I CHARGE)

(A) = a function of the Ex-Bus MW availability of Power (A) = a function of the Ex-Bus MW availability of Power Plant for the day declared before the day starts x Plant for the day declared before the day starts x SEB’s % allocation from the plantSEB’s % allocation from the plant

(B) = MWh for the day as per Ex-Bus drawal schedule for (B) = MWh for the day as per Ex-Bus drawal schedule for the SEB finalised before the day starts x Energy the SEB finalised before the day starts x Energy charge ratecharge rate

(C) = (C) = Σ Σ (Actual energy interchange in a 15 minute time (Actual energy interchange in a 15 minute time block – scheduled energy interchange for the time block – scheduled energy interchange for the time block) x UI rate for the time block block) x UI rate for the time block

TOTAL PAYMENT FOR THE DAY = (A) + (B) TOTAL PAYMENT FOR THE DAY = (A) + (B) ± (C) ± (C)

FEATURES :FEATURES :

((A) and (B) do not depend on actual plant A) and (B) do not depend on actual plant generation / drawal. No metering required for this generation / drawal. No metering required for this as they are based on off-line figures. All deviations as they are based on off-line figures. All deviations taken care of by (C)taken care of by (C)

No complication regarding deemed generation.No complication regarding deemed generation.

Perpetual incentive for maximizing generation and Perpetual incentive for maximizing generation and reducing drawal during deficit, but no incentive to reducing drawal during deficit, but no incentive to over generate during surplus.over generate during surplus.

UNSCHEDULED INTERCHANGES (UI)UNSCHEDULED INTERCHANGES (UI)I.E. DEVIATIONS FROM SCHEDULESI.E. DEVIATIONS FROM SCHEDULES

Makes all the players in the grid self-responsive and Makes all the players in the grid self-responsive and enhances merit order.enhances merit order.

Good UI helps in improving frequency and enables Good UI helps in improving frequency and enables one constituent to help the other (for meeting more one constituent to help the other (for meeting more consumer demand i.e reducing load shedding)consumer demand i.e reducing load shedding)

UI provides the mechanism for on-line displacement UI provides the mechanism for on-line displacement of costlier generation by cheaper generation : of costlier generation by cheaper generation : ultimate optimisation.ultimate optimisation.

REACTIVE ENERGY CHARGESREACTIVE ENERGY CHARGES

Under ABT, a reactive energy charge in Under ABT, a reactive energy charge in paise/kwh is applicable.paise/kwh is applicable.

This would be applicable for reactive power This would be applicable for reactive power exchanges outside the 97-103% voltage band.exchanges outside the 97-103% voltage band.

Planning CriterionPlanning Criterion

INDIAN POWER SECTORINDIAN POWER SECTOR

Generation LevelDemandMarginsLOLP

Generation MixPeak DemandEnergy Demand

Plant SelectionEconomicsGovt. PrioritiesTransmission RequirementResource Availability

Unit SizeEconomicsGrid StabilityResources

Generation Planning

Long Term Forecast

Load PotentialGeographyRate of GrowthResources

Short Term Forecast

Current Rate of growthResourcesFive year plansSuppressed demandIndustrial growthGovt. priorities

Load Forecasting

ISTS shall be capable of withstanding and be secured against the following outages without necessitating load shedding or rescheduling of generation during steady state operation.

Outage of a 132 kV D/C lineor

Outage of a 220 kV D/C lineor

Outage of a 400 kV S/C lineor

Outage of a single ICT

PLANNING CODE FOR ISTS

Planning Criteria :-

Continued …..

PLANNING CODE FOR ISTS Planning Criteria :-

or

Outage of one pole of HVDC bipole

or

Outage of 765 kV S/C line

The aforesaid contingencies would be superimposed over a planned outage

of another 220 kV D/C line or 400 kV S/C line in another corridor and not emanating from the same sub-station.

ISTS shall be capable of withstanding the loss of most severe single system infeed without loss of stability.

PLANNING CODE FOR ISTS

Planning Criteria :-

ANY ONE OF THE AFORESAID EVENTS SHALL NOT CAUSE

o loss of supply

o abnormal frequency on sustained basis

o unacceptable high or low voltage

o system instability

o unacceptable overloading of ISTS elements

REASONS FOR GRID CONTINGENCIESREASONS FOR GRID CONTINGENCIES

EQUIPMENT FAILURE

WEAK TRANSMISSION SYSTEM

OPERATIONAL ERROR

GRID INDISCIPLINE

MULTIPLE OUTAGES DUE TO WEATHER

CASCADED TRIPPING DUE TO OVERLOAD

Regualtory Framework

ROLE OF REGULATORY AUTHORITIESROLE OF REGULATORY AUTHORITIES

Central Electricity Regulatory Authority – CERCCentral Electricity Regulatory Authority – CERC

Regulate tariff of generating companies supplying power to more Regulate tariff of generating companies supplying power to more than one statethan one state

Determine Tariff & Regulate for Inter-state transmission system of Determine Tariff & Regulate for Inter-state transmission system of electricityelectricity

Specify terms and conditions for determination of tariffSpecify terms and conditions for determination of tariff Issue of licenses for Inter-state transmission & tradingIssue of licenses for Inter-state transmission & trading Dispute adjudication of various kinds including those amongst RLDC Dispute adjudication of various kinds including those amongst RLDC

and constituents and constituents Specify Grid codeSpecify Grid code Specify regulations for “ Open Access” Specify regulations for “ Open Access” Advise Central govt. on National Electricity policy & tariff policy, and Advise Central govt. on National Electricity policy & tariff policy, and

on efficiency & economy measures including investment promotionon efficiency & economy measures including investment promotion

ROLE OF REGULATORY AUTHORITIESROLE OF REGULATORY AUTHORITIES

State Electricity Regulatory Authority – SERCState Electricity Regulatory Authority – SERC

Similar functions at State level Generating companies & Intra-State Similar functions at State level Generating companies & Intra-State transmission of electricitytransmission of electricity

Issues Of Importance

ISSUES OF IMPORTANCE

Provide adequate level of redundancy in transmission network

Generation to be augmented with load increase

Load regulatory measures by utilities in the event of shortages

Adequate reactive compensation to be provided at load end

Issues of ImportanceIssues of Importance Uneven disposition of energy resources – long transmission Uneven disposition of energy resources – long transmission lineslines

Major Hydro resources in NER & NRMajor Hydro resources in NER & NR Coal reserves mostly in Bihar/Orissa/West Bengal Coal reserves mostly in Bihar/Orissa/West Bengal

Cost of power transmission lower than cost of fuel Cost of power transmission lower than cost of fuel transportationtransportation

Some Regions are no longer Self-sufficientSome Regions are no longer Self-sufficient

Major resources in SR exhausted Major resources in SR exhausted In NR hydro resources having long gestation periodIn NR hydro resources having long gestation period

Unbalanced Growth of different RegionsUnbalanced Growth of different Regions

Some regions are surplus and some are deficit.Some regions are surplus and some are deficit.

• Optimization of generation capacity additionOptimization of generation capacity addition Utilizing time diversityUtilizing time diversity Spinning reserve optimizationSpinning reserve optimization

Development of National Grid – Major ConsiderationsDevelopment of National Grid – Major Considerations

• Development in a phased mannerDevelopment in a phased manner – commensurate with – commensurate with

generation/ load growthgeneration/ load growth

• Conservation of Right-of-WayConservation of Right-of-Way - especially in areas with - especially in areas with

scarcity of ROW ---- viz. area near hydro, chicken-neck scarcity of ROW ---- viz. area near hydro, chicken-neck

area, forest area, town etc.area, forest area, town etc.

In forest area with rich flora & fauna, construction of line with high In forest area with rich flora & fauna, construction of line with high

towers ---- no forest cutting required.towers ---- no forest cutting required.

• Minimization of transmission costMinimization of transmission cost - immediate as well as - immediate as well as long-term basis.long-term basis.

• Flexible enoughFlexible enough to accommodate change in load- to accommodate change in load-generation pattern.generation pattern.

Major ChallengesMajor ChallengesProper Load Dispatch & Communication FacilitiesProper Load Dispatch & Communication Facilities POWERGRID is implementing ULDC schemes in all five POWERGRID is implementing ULDC schemes in all five

regionsregions..

Establishment of National Load Despatch Centre (NLDC) by Establishment of National Load Despatch Centre (NLDC) by

interconnecting all the regions.interconnecting all the regions.

Integrated Grid Operation Integrated Grid Operation Strict adherence to grid discipline to maintenance of voltage Strict adherence to grid discipline to maintenance of voltage

and frequency.and frequency.

Operation of generating units in free governor mode.Operation of generating units in free governor mode.

Implementation of “Availability Tariff” having provision of Implementation of “Availability Tariff” having provision of penalties and incentives to encourage grid discipline.penalties and incentives to encourage grid discipline.

MEN EQUIPMENT

PROCEDURE

Vital Elements:Vital Elements:

Departures From Conventional Practices:Departures From Conventional Practices:

Variation in Frequency permitted

Interchanges allowed to deviate from schedule

Frequency linked generation dispatch

Frequency linked pricing of deviations

Trading could be in the form of deviations with UI Rate providing the input

signal

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