This Nodal Protocol Revision Request (NPRR) clarifies the reporting requirements for Security-Constrained Economic Dispatch (SCED) constraints and aligns the Protocols with current practices.
Reason:
This NPRR clarifies Protocol language as to what should be reported regarding transmission constraint information. Network Security Analysis (NSA) is the application used to activate different constraints for economic dispatch by SCED. A constraint consists of a contingency and a monitored Transmission Element paired together.
Pursuant to Protocol requirements, the NSA results are currently provided on the Market Information System (MIS) Secure Area; however, the delineation of "active" versus "inactive" is not clear in the current Protocol language. As an example, an inactive constraint is not one in which ERCOT has determined to be inaccurate or inappropriate but rather one that is present in the Transmission Constraint Manager (TCM) that has not been selected for SCED resolution by ERCOT. This NPRR provides a firm delineation for active and inactive constraints, and separates the concept from contingencies that have been rendered ineligible due to being inaccurate or inappropriate. Such invalid contingencies, or contingencies identified by ERCOT as being incorrectly defined or otherwise in error, are already being posted to the MIS per Section per paragraph (6) of Section 5.5.1, Security Sequence.