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NPRR631

Summary

Title: Corrections to Definition of Credible Single Contingency
Next Group:
Next Step:
Status: Approved on 08/12/2014
Effective Dates:
08/13/2014

Action

Date Gov Body Action Taken Next Steps
08/12/2014 BOARD Approved
07/31/2014 TAC Recommended for Approval Board for consideration
07/17/2014 PRS Recommended for Approval TAC for consideration

Voting Record

Date Gov Body Motion Result
08/12/2014 BOARD To approve NPRR631 as recommended by TAC in the 7/31/14 TAC Report. Passed
07/31/2014 TAC To recommend approval of NPRR631 as recommended by PRS in the 7/17/14 PRS Report.
07/17/2014 PRS To endorse and forward NPRR631 and the associated Impact Analysis to TAC. 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.

Background

Status: Approved
Date Posted: Jun 17, 2014
Sponsor: ERCOT
Urgent: Yes
Sections: 2.1
Description: This NPRR seeks to restore proposed changes to NPRR540 that were represented in the 9/9/13 Constraint Management Plan Revision Request Workshop comments and endorsed by ROS as noted in the 9/16/13 ROS comments, but not included in the version recommended for approval by PRS in the 10/17/13 PRS Report, which was subsequently approved. As explained below, ERCOT believes the omission of these proposed changes from NPRR40 was inadvertent. The language ERCOT is specifically seeking to address is the definition of Credible Single Contingency, item (4). This item requires ERCOT to consider "G-1 + N-1" contingent events in Real-Time as well as other operational assessments, including Outage coordination. In practice, ERCOT does not consider such events in Real-Time operations. Rather, these contingent events have only been considered applicable in the Planning Horizon. After this item (4) language was included in the version of NPRR540 recommended for approval by PRS on 7/18/13, ERCOT submitted comments on 8/9/13 explaining that "G-1 + N-1" contingent events have only been considered applicable in the Planning Horizon, and since considerations for Credible Single Contingencies are contained in the Planning Guide, this language should be removed from the Protocols. ERCOT’s 8/12/13 comments on NPRR540 added that if the definition of Credible Single Contingency were to include this language, there could be impacts to ERCOT Energy and Market Management Systems. Following these comments, PRS tabled NPRR540 to allow the 9/9/13 Constraint Management Plan Workshop to be held. At the workshop, this issue was discussed, and the 9/9/13 Constraint Management Plan Workshop comments reflected a consensus to endorse NPRR540 as amended by the 8/13/13 CenterPoint Energy comments, which incorporated ERCOT’s revisions to the definition of Credible Single Contingency, and as revised by the workshop. However, at the 10/17/13 PRS meeting, PRS recommended to endorse the 7/18/13 PRS Report, which did not include the revisions contained in the 9/9/13 Constraint Management Plan Workshop comments. This version was subsequently approved by the ERCOT Board upon recommendation by TAC. By reaching back to the 7/18/13 PRS Report, the critical revisions to the definition of Credible Single Contingency were not included in NPRR540 as approved. ERCOT believes it was not the intent of PRS to omit these edits and proposes restoring these revisions in this NPRR. Based on the current definition of Credible Single Contingency, it appears that ERCOT is out of compliance with the requirements contained in that definition, because ERCOT does not consider "G-1 + N-1" contingent events in Real-Time operations. This NPRR will realign the Protocols with actual practice. ERCOT will also file a Notice of Protocol Violation with the Public Utility Commission of Texas (PUCT) to address the lack of alignment between the current Protocol definition of Credible Single Contingency and ERCOT’s actual Real-Time operations.
Reason: Addresses current operational issues

Key Documents

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