NPRR188

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

Date	Gov Body	Motion	Result	Abstentions
09/15/2009	Board of Directors	To approve NPRR188 as recommended by TAC in the 9/3/09 TAC Recommendation Report	Passed
08/25/2009	PRS	To endorse and forward the 7/23/09 PRS Recommendation Report and Impact Analysis for NPRR188 to TAC	Passed
07/23/2009	PRS	To recommend approval of NPRR188 as submitted.	Passed	1 Generator

Status:	Approved
Date Posted:	07/10/2009
Sponsor:	Ebby John on behalf of the Network Data Support Working Group (NDSWG)
Urgent:	No
Sections:	6.5.7.1.13
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 6.5.7.1.13. 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.