FERC Approval of Proposed Reliability Standards Related to Establishing and Communicating System Operating Limits (SOLs)

Summary:

The proposed Reliability Standards and NERC Glossary definitions enhance reliability by: (1) providing for greater clarity and uniformity in reliability coordinators’ SOL methodologies; (2) improving the coordination between planning and operations as it relates to analysis input assumptions and system performance criteria; (3) establishing a performance framework for determining SOL exceedance when performing operational planning analyses, real-time assessments, and real-time monitoring; (4) clarifying functional entity responsibilities for establishing and communicating each type of SOL and Interconnection Reliability Operating Limit (IROL), consistent with the Commission’s directive in Order No. 777; and (8) reducing redundancy and improving alignment with the transmission planning, transmission operations, and interconnection reliability operations Reliability Standards. Separately, NERC’s petition addressed the statement in Order No. 817 that “it appears that regional discrepancies exist regarding the manner for calculating IROLs.” NERC acknowledged that the directive in Order No. 817 remains outstanding. NERC explained that the standard drafting team originally intended to review the manner in which IROLs are established to address the regional discrepancies discussed in Order No. 817. NERC subsequently determined, however, that it would be beneficial to develop additional technical information on the establishment of IROLs prior to engaging in further standards development.

Additional Discussion:

On June 28, 2021, the North American Electric Reliability Corporation (NERC) filed a petition requesting approval of proposed Reliability Standards FAC-011-4 (System Operating Limits Methodology for the Operations Horizon), FAC-014-3 (Establish and Communicate System Operating Limits), FAC-003-5 (Transmission Vegetation Management), IRO-008-3 (Reliability Coordinator Operational Analyses and Real-time Assessments), PRC-002-3 (Disturbance Monitoring and Reporting Requirements), PRC-023-5 (Transmission Relay Loadability), PRC-026-2 (Relay Performance During Stable Power Swings), and TOP-001-6 (Transmission Operations). NERC also requested approval of: (1) modifications to the Glossary of Terms Used in NERC Reliability Standards to revise the definition of System Operating Limit (SOL) and to add a new term, System Voltage Limit; (2) the associated implementation plan, violation risk factors and violation severity levels; and (3) the retirement of Reliability Standard FAC-010-3 (System Operating Limits Methodology for the Planning Horizon).

Associated Files:

• 20220304-3004_RD22-2-000