Information Technology Standing Committee

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Multi Interval Optimization
Nicholas Ingman Holiday Inn - Oakville
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Multi Interval Optimization

• Agenda
• Objectives
• Multi Interval Optimization Function
• Dispatch Issues
• Proposed Implementation Schedule

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Objectives

• Operational Stability
• Facility cycling should be reduced relative to
  the current operation.
• Participants should be made aware of potential
  future dispatch instructions.
• Improved Transparency
• Manual intervention by IMO Control Room staff in
  the dispatch solution will be reduced
• Improved Compliance
• Non-compliance with the Dispatch Instructions
  will be reduced

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Objectives

• Improve Market Efficiencies
• Constraint payments caused by limited ramp
  capability should be reduced compared to present
  dispatch.
• Improved Operational Reliability
• Resources should be automatically scheduled in
  advance of present interval requirements to allow
  ramp rate capability to be used to solve for
  reliability concerns identified in future
  intervals.

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Basic Principles of MIO

• MIO maintains the current optimization objective
  as described in the Market Rules
• MIO will maximize the gain from trade over a
  forward looking horizon of up to 11 intervals
  (currently only uses a single interval)
• The number of optimized intervals is
  configurable, up to a maximum of 11. However due
  to performance requirements, the number of
  optimized intervals will be limited to 5
  (including the dispatch interval).

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Basic Principles of MIO

• The objective function will be configurable such
  that each interval's contribution to the overall
  optimization has a specific weight.
• The optimization will produce a
  security-constrained economic dispatch (SCED) for
  all dispatchable resources over the optimization
  horizon.
• The frequency of execution will be every 5
  minutes.

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Critical Intervals

• Critical intervals are intervals within the
  optimization period that provide the most
  efficient optimized dispatch solution as well as
  provide most beneficial information to facility
  operators.
• The critical intervals are used as input to the
  MIO calculation, and for preparing the dispatch
  advisories.
• Where there is a trade off between both
  objectives the intervals providing the better
  optimization have been selected.
• Critical intervals are selected for each interval
  based on defined selection criteria

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Output of the MIO Sequence

• The schedules for the first interval are to be
  issued to the respective market participants in
  the form of dispatch instructions.
• The schedules for the remaining critical
  intervals are to be communicated to the
  respective market participants in the form of
  Dispatch Advisories (DA)

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Dispatch Issues

• Market Participants have identified a number of
  Real Time dispatch issues that result in dispatch
  instructions that generation facilities are
  either unable to physically follow or may cause
  equipment damage.
• As a result, a number of modifications have been
  defined for the RTC DSO in an effort to more
  accurately reflect the physical characteristics
  of facilities

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Reflecting Unit Ramp Capability

• The DSO causes a stutter step in fossil loading
  when a unit starts to increase output from either
  a steady load or a loading rate less than the
  offered rate. This is a result of the snapshot
  that reflects the unit actual loading when
  calculating the next interval Dispatch
  Instruction.
• The DSO should account for the initial slow
  loading characteristic of non-quick start
  facilities.
• The unit ramp capability will factor in the most
  limiting of two combinations.
• Last dispatch and offer ramp rate
• Actual output and maximum ramp rate

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Reflecting Unit Ramp Capability
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Reflecting Unit Ramp Capability
13
Operating Reserve Activation

• During operating reserve activations, fixed
  constraints are applied to facilities that have
  been activated.
• A unit minimum constraint should be set
  (instead of the fixed) when facilities are
  activated for operating reserve.
• This is a change from the current practice of
  fixing the unit at the operating reserve
  activation dispatch level.

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Minimum Loading Point

• Many facilities have a requirement to operate at
  or above a minimum output level or loading
  point
• The RTC DSO should not schedule these units below
  this minimum output level unless the unit is
  synchronizing or shutting down.

15
Start Up and Shut Down

• Treatment of Units Starting Up or Shutting Down
• When a non-quick start unit synchronizes, it must
  ramp up to its minimum loading point.
• If the unit is dispatched below its minimum
  loading point, it must ramp down to zero and be
  removed from service.
• After a non-quick start unit synchronizes it must
  be dispatched to minimum load or above.

16
Start Up and Shut Down

• Treatment of Units Starting Up or Shutting Down
• While on line the unit should never be dispatched
  below minimum unless predispatch indicates the
  unit is to be de-committed in the hour.
• The control room operator must manually approve
  the de-commitment of a unit (approve dispatching
  below minimum to begin the shutdown event) in the
  RTC DSO.

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Dispatch Trajectory

• Ensure that thermal units will not reverse
  direction without a minimum period (adjustable
  variable of 0, 1 or 2 intervals) of steady
  operation.
• After the minimum period of steady operation, the
  unit is available to be normally dispatched.

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Forbidden Operating Range

• Hydraulic units have operating ranges where the
  units are unable to maintain steady operation
  without causing equipment damage.
• Multiple forbidden ranges for aggregated
  facilities should be respected, up to a maximum
  of 3.
• Each forbidden range is to be offered as a
  separate price segment.

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Dispatch Advisories

• Issued to all dispatchable market participant
  facilities
• For each interval, a Dispatch Instruction will be
  issued plus the addition of up to 4 dispatch
  advisories for future intervals.
• Participant specific Dispatch Advisory reports
  should be available for all participants to view
  on demand from the participants dispatch
  workstation.
• The report will contain the energy and OR
  components of the dispatch advisory and indicate
  the specific intervals that each component
  relates to.
• This report will not contain the Dispatch
  Instruction.

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Dispatch Advisories

• Initial implementation via a Private MP Report
• Feasibility Testing is currently underway
• Supporting Infrastructure (APP252) is scheduled
  for Release 11.0
• XML Schema and Stylesheets will be published
  early next year after review with MIO Working
  Group

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Dispatch Advisory - Sample
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Release 8.1 Deliveries

• The following changes are proposed to be
  implemented as part of Software Release 8.1 on
  December 10
• Reflecting Ramp Rate Capability
• Operating Reserve Activation
• Modifications to PLC to capture resource specific
  data (Minimum Loading Point, Forbidden Regions
  etc.)

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New PLC Screen
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Proposed MIO Project Schedule
Apr-03
Jun-03
Apr-04
Aug-03
Oct-03
May-04
Dec-03
Feb-04
Requirements and Detailed Design Definition
Build Test
Commissioning and Market Trials

• R 8.1 - Introduction of
• RD Changes for OR
• Respecting Ramp Rate Capability and
• PLC Modifications to capture Resource Specific
  Data

Decision to Go - Live
Proposed timeline is dependent on finalization of
participants implementation schedules