Title: MVA for SCED Input
Next Group:
Next Step:
Status: Approved on 09/15/2009
Effective Dates:

or per the Nodal Protocol Transition Plan http://www.ercot.com/mktrules/protocols (10/01/09 Nodal Protocols Library)


Date Gov Body Action Taken Next Steps
07/23/2009 PRS Recommended for Approval PRS Impact Analysis Review
09/03/2009 TAC Recommended for Approval ERCOT Board Consideration
08/25/2009 PRS Recommended for Approval TAC Consideration
09/15/2009 BOARD Approved

Voting Record

Date Gov Body Motion Result
07/23/2009 PRS To recommend approval of NPRR188 as submitted. Passed
09/03/2009 TAC Passed
08/25/2009 PRS To endorse and forward the 7/23/09 PRS Recommendation Report and Impact Analysis for NPRR188 to TAC Passed
09/15/2009 BOARD To approve NPRR188 as recommended by TAC in the 9/3/09 TAC Recommendation Report Passed

Vote tallies here reflect individual votes, not the weight of the votes by market segment. Affirmative votes are not recorded in these vote tallies. For additional details on the voting record, please consult the Recommendation or Action Report, or the official vote tally if available, as posted in the key documents.


Status: Approved
Date Posted: Jul 10, 2009
Sponsor: Ebby John on behalf of the Network Data Support Working Group (NDSWG)
Urgent: No
Description: This Nodal Protocol Revision Request (NPRR) removes the Transmission Service Provider (TSP) requirement to provide MVA to be used in Real-Time sequence and Security-Constrained Economic Dispatch (SCED). This NPRR also corrects the use of Common Information Model (CIM) and corrects the Dynamic Rating requirement.
Reason: MVA values from a TSP or any Market Participant are not used within State Estimator solutions except in the case of a Dynamic Rating. The ERCOT Energy Management System (EMS) is not designed to accept MVA values for equipment except as a Dynamic Rating. The ERCOT State Estimator, and subsequently contingency analysis, utilizes MW and Mega Volt-Amperes reactive (MVAr) Inter-Control Center Communications Protocol (ICCP) data to determine an MVA value which then may be passed to SCED if needed. The State Estimator/contingency analysis-determined MVA value is used to compare with the Market Participant provided ratings, including Dynamic Ratings, and is captured as a Real-Time sequence and SCED requirement pursuant to paragraph (1) (b) of Section This NPRR also replaces CIM with Network Operations Model as Common Information Model (CIM) is a format. All MVA ratings are provided and are utilized by ERCOT in maintaining the reliability of the ERCOT Transmission Grid.

Key Documents

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