BPM Changes Required for Real-Time SFOR Implementation
The following are proposed changes to the Market Operations BPM, for implementation of the Simplified Forbidden Operating Region (SFOR) functionality for the Real-Time Market. The changes affect sections 4.5 and 7.8.2.4.
For a complete text of the Market Operations BPM, please see the CAISO web site at: https://bpm.caiso.com/bpm/bpm/version/000000000000005.
4.5 Ancillary Services Considerations
This section identifies important considerations in the use and procurement of Ancillary Services, including:
Ø The Operating Reserve Ramp Rate for Energy within the AS capacity is a single Ramp Rate, which is distinct from the Operational Ramp Rate, and is the same for Spinning and Non-Spinning Reserve.
Ø Energy Limits of resources bidding into the AS market can be managed by the use of the Contingency Only designation supplied by the SC in the AS Bid. The Contingency Only designation applies for the entire Trading Day. In Real-Time, Energy from Contingency Only Operating Reserves is only cleared against Demand only under Contingency situations.
Ø Day-Ahead SC trades of Ancillary Service Obligations are supported,supported; however, physical trades of Ancillary Services capacity is not.
Ø Forbidden Operating Regions may limit the procurement of Ancillary Services. Specifically, the procurement of Regulation Up, Spinning Reserve, and Non-Spinning Reserve may be limited by the lower bound of a Forbidden Operating Region, and the procurement of Regulation Down may be limited by the upper bound of a Forbidden Operating Region. For the hourly DAM AS procurement, a resource must be able to cross its FOR within 20 minutes in order to be eligible to provide AS for that Trading Hour. For RTM AS procurement, unless a resource can complete the crossing of its FOR within the relevant 15 minute RTUC interval, it is ineligible to provide AS and will thus not be called upon to provide AS for that interval., unless that Forbidden Operating Region can be crossed within 20 mins for the hourly DAM AS procurement or 5 mins for the 15 minute RTM AS procurement.
Ø In the DAM, Forbidden Operating Regions may limit the procurement of Ancillary Services. Specifically, the Regulation Up, Spinning Reserve, and Non-Spinning Reserve may be limited by the lower bound of a Forbidden Operating Region, if the optimal dispatch is below that Forbidden Operating Region, and Regulation Down may be limited by the upper bound of a Forbidden Operating Region, if the optimal dispatch is below that Forbidden Operating Region, unless that Forbidden Operating Region can be crossed within 20 minutes.
Ø In the RTM, Forbidden Operating Regions constraint is not enforced. If the CAISO is not enforcing Forbidden Operating Region constraint in RTM, incremental A/S procurement in RTM from a resource will not be constrained by the Forbidden region of the resource.
Ø Bids to export AS are not supported in the CAISO Markets.
Ø Export of on-demand obligations of AS are manually supported but cannot be procured from the DAM or RTM.
Ø All Spinning and Non-Spinning Reserves awarded in RTM are automatically classified as Contingency Only. Furthermore, any DA Spinning and Non-Spinning Reserve Awards are re-classified as Contingency Only if additional Spinning or Non-Spinning Reserve is awarded in the RTM. See CAISO Tariff Section 34.2.2.
Ø Any AS designated as Contingency Only is not normally dispatched as Energy in the normal RTED mode. In the Real Time Contingent Dispatch (RTCD) mode, Energy behind Contingency Only AS and non-Contingency Only AS is not distinguished, and is dispatched economically.
7.8.2.4 Forbidden Operating Regions
Forbidden Operating Regions (FORs) are distinct non-overlapping operating regions within which Generating Units cannot operate stably. A Generating Unit may be scheduled or Dispatched within an FOR in an interval only if it takes longer than the duration of the interval to cross that region. In such case, the Generating Unit must be scheduled or Dispatched in subsequent intervals in the same direction (up or down) so that it clears the FOR in the least number of intervals possible. Depending on its Crossing Time, a resource may be dispatched to the boundary of its FOR before proceeding to cross the FORPrior to crossing the FOR, the Generating unit will first be dispatched to the FOR boundary, then cross in subsequent interval(s).
Moreover, a Generating Unit scheduled or dispatched within an FOR in an interval is not eligible to provide Ancillary Services in that interval.
FORs are static and defined in the Master File along with all other resource characteristics. There is support for up to four FORs for a given Generating Unit, however, not all resources have FORs. The market applications obtain the static FOR definition directly from the Master File along with all other resource characteristics. The Operational Ramp Rate Bid is currently limited by SIBR validation to four segments without regard to FORs.
The Forbidden Operating Region Ramp Rates, are static and are included in the FOR definition in the Master File, albeit not as Ramp Rates, but as Crossing Times; an average Ramp Rate can be derived by dividing the range of the FOR with its Crossing Time.
If there are registered FORs for the Generating Unit and the Bid period specified in the Bid, the Operational Ramp Rate curve specified in the Generating Unit Operational Ramp Rate Bid component is modified so that the operating range covering each FOR has an operational ramp rate equal to the ratio of the FOR range over the corresponding registered Crossing Time, subject to the 10:1 rule specified in section 6.6.2 of this BPM.
FOR constraint will not be enforced in RTM. With Forbidden Region enforced in DAM, the resource already has information and feasible schedules reflecting its transition through Forbidden Region. In Real-Time, when first dispatch enters Forbidden Region in the upward direction, resource may need to be constrained from below by the upper end of Forbidden Region to ensure resource transits through Forbidden Region. This constraint may be in the form of Exceptional Dispatch by the CAISO Operator for reliability or SLIC ticket put in by the SC and will prevent the resource from returning to lower Forbidden Region range prior to minimum period of time has passed or operating conditions have relaxed. Similarly, when first dispatch enters Forbidden Region in the downward direction, resource may need to be constrained from above by the lower end of Forbidden Region to ensure resource transits through Forbidden Region. This constraint may be in the form of Exceptional Dispatch by the CAISO Operator for reliability or SLIC ticket put in by the SC and will prevent the resource from returning to upper Forbidden Region range prior to minimum period of time has passed or operating conditions have relaxed.
CAISO/gford Rev. 1/2013/09