ANCILLARY SERVICES
THE NEXT STEP IN MARKET
GRANULARISATION
DEFINITION
Ancillary services are defined as all those
activities on the interconnected grid that
are necessary to support the transmission
of power in maintaining and ensuring
reliable operation and the required
degree of quality and safety.
WHY ANCILLARY SERVICES?
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SYSTEM OPERATOR DUTIES
CONTROL THE FREQUENCY OF THE SYSTEM WITHIN
CERTAIN BOUNDS.
CONTROL THE VOLTAGE QUALITY AND PROFILE OF
THE SYSTEM WITHIN CERTAIN BOUNDS
MAINTAIN STABILITY OF THE SYSTEM
PREVENT OVERLOADS IN THE TRANSMISSION SYSTEM
RESTORE THE SYSTEM OR PORTION OF THE SYSTEM
AT THE EARLIEST WHEN REQUIRED.
TRANSPARENCY IN THE SYSTEM
WHAT ARE ANCILLARY SERVICES
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Unbundled Services to
facilitate market
operations
Voltage Support
Regulation
Help to maintain
reliable operation
Reserves
Scheduling
Consists of physical
equipment and human
resources Support
NERC IDENTIFIED AND DEFINED
12 SERVICES
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SYSTEM CONTROL
VOLTAGE CONTROL
REGULATION
OPERATING
RESERVES
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SPINNING
SUPPLEMENTAL
ENERGY IMBALANCE
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LOAD FOLLOWING
LOSS REPLACEMENT
BACKUP SUPPLY
DYNAMIC
SCHEDULING
SYSTEM BLACK-START
NETWORK STABILITY
FERC REQUIRES THESE 6
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NORMAL OPERATIONS REQUIRE 6 SERVICES
TO MAINTAIN GENERATION/LOAD BALANCE
System control
Voltage control
Regulation
Energy imbalance
Load following
Loss replacement
FERC ANCILLARY SERVICES
CATEGORY -1
CATEGORY-1: SERVICES REQUIRED FOR ROUTINE
OPERATION
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SYSTEM CONTROL
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VOLTAGE CONTROL
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THE INJECTION OR ABSORPTION OF REACTIVE POWER FROM
GENERATORS OR CAPACITORS TO MAINTAIN SYSTEM VOLTAGES
WITHIN REQUIRED RANGES.
REGULATION
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THE CONTROL AREA OPERATOR FUNCTIONS THAT SCHEDULE
GENERATION AND TRANSACTIONS AND CONTROL GENERATION IN
REAL-TIME TO MAINTAIN GENERATION/LOAD BALANCE.
THE USE OF GENERATION OR LOAD TO MAINTAIN MINUTE-TOMINUTE GENERATION/LOAD BALANCE WITHIN THE CONTROL
AREA.
LOAD FOLLOWING/ENERGY IMBALANCE
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THE USE OF GENERATION TO MEET THE HOUR-TO-HOUR AND
DAILY VARIATIONS IN LOAD
FERC ANCILLARY SERVICES
CATEGORY -2
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CATEGORY-2: SERVICES NEEDED TO PREVENT
AN OUTAGE FROM BECOMING A CATASTROPHE
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SPINNING RESERVES
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SUPPLEMENTAL RESERVES
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NETWORK STABILITY SERVICES
CATEGORY-1 CAN ALSO ACT LIKE CATEGORY-2
SERVICES AND PREVENT VOLTAGES FROM
DECAYING SO FAR THAT VOLTAGE COLLAPSE
OCCURS, AND SYSTEM CONTROL IS REQUIRED
TO MANAGE THESE SERVICES.
FERC ANCILLARY SERVICES
CATEGORY -3
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CATEGORY-3: SERVICES NEEDED TO RESTORE
THE SYSTEM AFTER A BLACKOUT
SYSTEM BLACKSTART CAPABILITY
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THE ABILITY OF A GENERATING UNIT TO PROCEED
FROM A SHUTDOWN CONDITION TO AN OPERATING
CONDITION WITHOUT ASSISTANCE FROM THE
ELECTRICAL GRID AND THEN TO ENERGIZE THE
GRID TO HELP OTHER UNITS START AFTER A
BLACKOUT OCCURS.
RESERVES
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IMPORTANT FOR BOTH ENERGY AND
REACTIVE POWER
NEEDED FOR MAINTAINING THE
INTEGRITY OF THE TRANSMISSION
SYSTEM
DESIGNED TO RESPOND TO
UNCERTAINITIES
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GENERATION OUTAGE
LOAD VARIATIONS
TYPES OF RESERVES
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SPINNING:
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SUPPLEMENTAL
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FREQUENCY STABILISATION
AVAILABLE INSTANTLY
TIME OF RESPONSE – FEW SECONDS TO 5 MINUTES
CAN BE FAST START UNITS OR DMS LOADS
NO MANUAL INTERVENTION
ENERGY REQUIRED IS NOT LARGE
ON-BARS FOR SHORT PERIODS OF TIME
ENERGY BALANCING
TIME OF RESPONSE – SEVERAL MINUTES TO HALF-HOUR
MAY REQUIRE MANUAL INTERVENTION
LARGER ENERGY REQUIREMENTS
BACK-UP
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TIME OF RESPONSE – MORE THAN HALF-HOUR
EXPECTED TO STAY ON BARS FOR A LONGER PERIOD
FREQUENCY REGULATION
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PRIMARY FREQUENCY CONTROL
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SECONDARY FREQUENCY CONTROL
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DROOP SETTING
FREQUENCY RESPONSE OF HVDC LINK
AUTOMATIC GENERATION CONTROL
DIRECT CONTROL OF SPECIFIED PLANTS
ABILITY TO DISCONNECT DEMAND
FREQUENCY CONTROL CAN ALSO BE ATTAINED
BY SENDING PRICE SIGNALS TO
GENERATORS(ABT?)
FREQUENCY RANGE AND ACTIONS
FREQUENCY BAND
AVERAGE RESERVE CLEARING
PRICES IN NYISO IN 2002
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10 Minute Spin
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East: $3.03
West: $2.82
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10 Minute Non Synch
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East: $1.51
West: $1.27
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30 Minute Reserve: $1.13
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LOAD-FOLLOWING
RESERVE
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TYPICALLY 1% OF CAPACITY IS OF THIS
TYPE
LINKED TO AGC AND FGMO
HIGHER O&M COSTS AND HEAT RATES
COST INCLUDES FIXED COSTS
FIXED COSTS ARE HIGHER SINCE
LIFETIME OF THE UNIT IS LOWERED
REACTIVE SUPPORT SERVICES
VOLTAGE CONTROL EQUIPMENT
NETWORK STABILITY SERVICES
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MAINTENANCE AND USE OF SPECIAL
EQUIPMENT (POWER-SYSTEM
STABILIZERS AND DYNAMIC-BRAKING
RESISTORS) TO MAINTAIN A SECURE
TRANSMISSION SYSTEM.
PROVIDING ANCILLARY SUPPORT
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ANCILLARY SERVICE CAN BE ARRANGED BY
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OWNING THE EQUIPMENT NECESSARY TO
PROVIDE THE SERVICE
CONTRACTING WITH THE ANCILLARY
SERVICE PROVIDERS ON A LONG TERM BASIS
CREATING A MARKET FOR SUPPLY OF
SERVICE.
PRICING ANCILLARY SERVICES
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COSTS ARE NOT TRIVIAL :- 10% OF ENERGY
CHARGES ARE TOWARDS ANCILLARY SERVICES
IN USA
SIZING HAS TO BE DONE FOR THE GRID BASED
ON REGULATORY REQUIREMENT
RESOURCES HAVE TO BE GROUPED IN
DIFFERENT SERVICES BASED ON HARD DATA :DETERMINING THE SERVICE QUALITY ORDER
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CRUCIAL FOR BIDDING
COSTING IS USUALLY ON REPLACEMENT COST,
LOST PROFITS AND OPPORTUNITY COSTS
TYPICAL PRICING IN CALIFORNIA
ISO
ABT AND THE ANCILLARY MARKET
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CONCEPT OF LOOSE POWER POOL
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REACTIVE POWER PRICING MECHANISM IN PLACE FOR THE LOOSE
POWER POOLS
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THIS IS FOR THE AREA AS A WHOLE
REACTIVE SUPPORT MAY STILL BE REQUIRED AT VARIOUS BUSES
THIS OPENS UP A MARKET OPPURTUNITY
PRESENTLY MVAR BY GENERATORS ARE NOT COMMERCIALLY
MONITORED
UI MECHANISM PROVIDES A COMPREHENSIVE BALANCING MARKET
AND A PRICING THRESHOLD FOR EMBEDDED ANCILLARY
SERVICES/MARKETS
REGULATOR HAS PROVIDED LARGE BANDWIDTH FOR FREQUENCY
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RESPONSIBILITY OF RESERVES, LOAD FOLLOWING ETC LIES WITH THE
STATES
RESERVES, LOAD FOLLOWING ETC IN STATE PURVIEW
LOAD FOLLOWING, SPINNING RESERVES YET TO MATURE
FGMO ALREADY IN PLACE AS MANDATED SERVICE
AVR IN SERVICE IS ALSO MANDATED
DUE TO UNBUNDLING GENCO’S MAY NOT READILY PART WITH FREE
SERVICES LIKE IN THE PAST
UI PROVIDES THE REFERENCE PRICE FOR MW BASED
IMBALANCE ANCILLARY SERVICES
ISGS
STATE
SYSTEM
POWER POOL
ABT
UI
PRICE
OPPORTUNITY
FOR
PROCURING
MVAR FROM
ISGS AS AN
ANCILLARY
SERVICE