1 / 16

GTBD Forecasting Presentation to WMS

This presentation discusses the GTBD forecasting methodology and the implementation of SCED to produce projections of future Locational Marginal Prices (LMPs). It covers examples of ERCOT system load, analysis of forecasting errors, and the next steps for implementation.

haskins
Download Presentation

GTBD Forecasting Presentation to WMS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GTBD ForecastingPresentation to WMS Using SCED to Produce Projections of Future LMPs Floyd J. Trefny April 8, 2011

  2. Topics • ERCOT System Load Examples • Sunday, January 30, 2011 • Thursday, February 3, 2011 • GTBD Forecasting Methodology • Analysis of Forecasting Errors • Two Days • February 5 through March 8, 2011 • Implementation in SCED • Next Steps

  3. Average Mw Change in Mw/Min over 15-minute SCED interval

  4. Average Mw Change in Mw/Min over 15-minute SCED interval

  5. GTBD Forecasting Methodology • GTBD (Generation To Be Dispatched) is the sum of the Base Points dispatched in SCED • Typically, calculated by summing up the current actual generation from all the Generation Resources that are going to be dispatched by SCED • SCED LMPs are based on this amount of total power • A reasonable forecast of future GTBD can be calculated from: • System ramp rate sampled over the last fifteen minutes • Ramp rate may be positive or negative • Add: Real-Time SCED GTBD + (Ramp Rate*15) gives the “Forecasted GTBD”

  6. Frequency of Forecast Error

  7. Implementation in SCED HUB SUPER HUB HUB HUB • In addition to the existing SCED, execute the same SCED algorithm, but using the Forecasted GTBD • Use same offer curves, Resource Limits and Status that were available to SCED for the actual dispatch of generation • Assume that the same transmission constraints that are active in real time SCED are also active in the Forecast SCED calculation • Post on MIS, the LMP’s generated for: • Resource Nodes • Hubs • Load Zones (LMPZ) • Provide via ICCP?? HUB Generation Load

  8. Execution Timing SCED Execution Projections are 15 minutes into the future updated typically every 5 minutes

  9. NPRR Language Suggested • 6.5.7.3 Security Constrained Economic Dispatch • For each SCED process, ERCOT shall calculate a rolling 15 minute projection of the Resource Node LMPs, Hub LMPs, Load Zone LMPs, and LMPs for each Electrical Bus based on the same inputs to the SCED process as described in this section, except for the Resource’s HDL and LDL and the total generation requirement will be as estimated at the end of the next 15 minutes. The Resource’s HDL and LDL will be calculated based on ramping over 15 minutes. ERCOT shall estimate the 15 minute projected total generation requirement by estimating the change in generation requirements in the next 15 minutes and adding such to the current actual generation requirement as was determined by LFC and used to produce the current SCED interval prices. ERCOT shall post the 15-minute projected LMPs for Resource Nodes, Hub LMPs, Load Zone LMPs, and LMPs for each Electrical Bus on the MIS Public Area according to Section 6.3.2, Activities for Real-Time Operations. In addition, ERCOT shall post the projected sum of LDL and projected sum of HDL for all Generation Resources and the projected 15 minute total generation requirement on the MIS Public Area according to Section 6.3.2.. • 6.3.2 Activities for Real-Time Operations • Post to the MIS Public Area, the 15-minute projected LMPs created by each SCED process for each Resource Node. Post the 15-minute projected Hub LMPs, Load Zone LMPs, and LMPs for each Electrical Bus via the MIS Public Area. These projected prices shall be posted immediately subsequent to deployment of Base Points from SCED with the time stamp of the SCED process that produced the projections. • Post to the MIS Public Area the sum of the projected of LDL and HDL for all Generation Resources and the total generation requirement used to calculate LMP projections.

  10. Next Steps WMS discussion and potential motion Get Comments from ERCOT Staff Seek expedited implementation to support Quick Start objectives and demand response

  11. Proposed WMS Motion The WMS supports the concept of the protocol change outlined in the draft NPRR titled, “Calculate and Post Projected Non-Binding LMPs for the Next 15 Minutes”, dated March 28, 2011 and urges PRS and ERCOT to expedite its implementation.

  12. Discussion

  13. Appendix

  14. SCED UP and SCED Down

More Related