Incorporating HVDC in AESO’s Loss Factor Model

Incorporating HVDC in
AESO’s Loss Factor Model
Peng Wang, Alberta Electric System Operator
Robert (Bob) Burton, Teshmont Consultants LP
February 26, 2013
Outline
• Background
• Project scope and objectives
• HVDC losses incorporation in the 5th year loss factor forecast
• HVDC losses incorporation in the next year loss factor
calculation
• Schedule
Public
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Background
• Two 500 kV high-voltage
direct-current (HVDC) lines,
East Alberta Transmission
Line (EATL) and West
Alberta Transmission Line
(WATL), are expected to
come in service in 2014
(EATL) and 2015 (WATL),
subject to further updates
Muskeg
River
Aurora
Horizon
Syncrude
MacKay
Joslyn
Jackpine
Wesley
Creek
Dover
Millenium
(Suncor)
Ruth Lake
Livock
Kinosis
McMillan
Brintnell
Little
Smokey
Conklin
Whitefish
Lake
Heartland
Marguerite
Lake
Wabasca
Louise
Creek
Christina
Lake
Leismer
Heart Lake
Mitsue
Deerland
N.
Barrhead
Heathfield
Amelia
Alberta
Newsprint
Wabamun
Bannerman
Castle
Downs
N. Calder
Josephburg
Bellamy
Victoria
Sagitawah
Argyle
Jasper
EATL
North end: Heathfield
South end: Newell
Lamoureux
East
Edmonton
Clover Bar
Petrolia
East Industrial
Lambton
Bickerdike
Dome
Sunnybrook
Summerside
Sundance
Ellerslie
Keephills
Nisku
Genesee
Brazeau
Wolf
Creek
Bigstone
Battle River
Gaetz
Metiskow
Nevis
Benalto
Nilrem
Paint Earth
Hazel
Coyote
Lake
WATL
North end: Genesee
South end: Langdon
Hansman
Lake
Cordel
Red Deer
Johnson
East
Crossfield
Twin
Lakes
Beddington
Pemukan
Anderson
Sheerness
Oakland
Sarcee
Janet
Lanfine
Ware
Junction
Crossings
Langdon
Cypress
Shepard
East
Calgary
Amoco
Empress
Jenner
Bennett
SS-65
Cassils
Milo
West
Brooks
Foothills
Newell
S.C.
To British
Columbia
Picture Butte
“MATL”
Fidler
Chapel
Rock
Bowmanton
Peigan
Journault
Whitla
Goose
Lake
Public
North
Windy Lethbridge
Flats
To
Montana
3
Background
Timeline of Loss Factor (LF) Posting
2013-11-01
2014 next year LF
2013-10-01
2014-01-01
2014-03-31
2018 5th year LF forecast
2014-04-01
2014-07-01
2014-11-07
2015-03-31
2015 next year LF 2019 5th year LF forecast
2014-10-01
2015-01-01
2014-10-15
Cut-off date for projects to be included in
2014 next year LF
2015-04-01
2015-07-01
2015-11-06
2016 next year LF
2015-10-01
2015-10-15
Cut-off date for projects to be included in
2015 next year LF
• The first HVDC line (EATL) in Alberta is expected to be energized
after the cut-off date for projects to be included in the 2014 loss
factor calculation (October 15, 2014). Therefore, HVDC is not
included in the 2014 loss factor calculation
Public
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Background
• Based on the in-service date and the current ISO Rules,
the HVDC lines will be incorporated in the 2015 next year loss
factor calculation. This calculation will be completed and posted
in November 2014
• In the 5th year loss factors forecast, HVDC schemes have been
replaced by equivalent AC schemes for the loss factor software.
For further information, please refer to the AESO’s website:
www.aeso.ca > Transmission > Loss Factors > Current
Consultation
• HVDC schemes have to be modeled in the next year loss factor
calculation (2015)
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Project Scope and Objectives
• Project Scope
– Subsequent to the AC patch used by AESO in the 5th year loss
factor forecast, a DC software solution is now underway
– This DC software solution is independent of the loss factor
methodology, which means the model is flexible to be used with other
methodologies
• Project Objectives
– Enhance the capability of the current loss factor calculation
to incorporate HVDC schemes in the load flow models and the
incurred HVDC losses
– Represent HVDC losses in the loss factor calculation to maintain the
accuracy in the calculation
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HVDC Losses Incorporation in the 5th Year
Loss Factor Forecast
• HVDC losses
– HVDC converter losses
•
Resistances are calculated based on the dispatched flow
– HVDC transmission line losses
• HVDC dispatch
– In the current 5th year loss factor forecast, HVDC are dispatched
based on the South of KEG (SOK) flow
– The next year loss factor calculation will be consistent with the
HVDC dispatch strategy used in operation (to be determined)
• Current method
– PSS/E (load flow software) correctly calculates the DC losses in load
flow base cases
– The current loss factor software does not directly reflect DC losses
when calculating loss factors
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HVDC Losses Incorporation in the 5th Year
Loss Factor Forecast
• Use of AC equivalent lines to represent DC converters and lines
• Why?
– Loss factor software does not account for DC losses
– With equivalent AC Circuit, losses are accounted for
• How is it done?
– DC scheme is replaced by an equivalent AC scheme, which
includes 500 kV AC circuit in series with a lossless phase shifter
and step up transformer
– Shunt devices are added at each end
– AC circuit resistance selected to give same end to end losses
as DC
– Phase angle adjusted to give same real power flow at each end
– Shunt compensation to give same var flow at each end
Public
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HVDC Losses Incorporation in the 5th Year
Loss Factor Forecast
• Advantage and limitation of the current method?
– DC losses are accounted for
– Misrepresents current thinking on DC dispatch
– Model implies that DC dispatch would be automatically changed
to reflect changes in generation and load
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HVDC Losses Incorporation in the Next
Year Loss Factor Calculation
• Technical details of the proposed model and method
– Do not replace DC with AC
– Change software to account for DC losses
– Assume no change in dispatch for small changes in generation
– DC losses would be “socialized”
• Rationale of the proposed method
– DC dispatch likely to be changed periodically during the day and
hence would not react to small changes in generation
– Impact of DC dispatch would be reflected in base case load flows
• What’s changed and what remains the same in the next year
loss factor calculation?
– No changes would be required to the next year loss factor
methodology
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HVDC Losses Incorporation in the Next
Year Loss Factor Calculation
• Advantages of the proposed method
– Accurately reflects likely mode of operation
– DC losses are accounted for at the load flow level
– No real limitations
• What’s different from the current method used in 5th year loss
factor forecast?
– Both methods account for DC losses, but new method reflects
the more likely method of dispatching the two DC systems
• What’s the impact on loss allocation and loss factors?
– DC losses are socialized rather than allocated to specific
generators
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HVDC Losses Incorporation in Next Year
Loss Factor Calculation
• Validation through testing of the new method/changes
– Impact of DC model on loss factors will be demonstrated by
repeating 5th year loss factor calculations and publishing results
• Loss factor methodology is not changed
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Schedule
Milestones
Dates
Presentation to stakeholders
February 26, 2013
AESO/Teshmont review of proposed
software solution
March 2013
Software update
April 2013
Software testing
June 2013
Complete testing and finalize software
July 2013
Second stakeholder session
September 2013
Release the final version of the loss
factor software by AESO
October 2013
• Updated software will be used for the 2018 5th year loss factor
forecast, which will be posted in March 2014
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If you have further questions please send to
[email protected]
Thank you