NERC Publishes Inverter-Based Resource Strategy Document

by Leland McMillan, NERC Services Supervisor

The rapid interconnection of Bulk Power System (BPS)-connected inverter-based resources is one of the most significant drivers of grid transformation and poses a high risk to BPS reliability. NERC has developed an Inverter-Based Resource Strategy document for addressing inverter-based resource performance issues that illustrates current and future work to mitigate emerging risks in this area. The strategy, which was developed to ensure industry awareness and alignment regarding ERO Enterprise and NERC Reliability and Security Technical Committee activities, also addresses the Member Representatives Committee’s policy input requesting enhancements in this area.

Two recent Disturbance Reports were cited:

August 2022:

The Panhandle Wind Disturbance Texas event of March 22, 2022 Joint NERC and Texas RE Staff Report contains the ERO analysis of a reduction of wind resources across the Texas Panhandle area that occurred during two faults in the morning of March 22, 2022 up to around 200 miles from the initiating fault. While the event did not meet the qualified criteria for a Category event per the ERO Event Analysis Process, NERC, and Texas RE worked closely with ERCOT and the affected facility owners to conduct root cause analysis and identify recommendations related to the abnormal wind performance issues observed.

April 2022:

The report, “Multiple Solar PV Disturbances in CAISO Disturbances between June and August 2021 Joint NERC and WECC Staff Report” contains the ERO analysis of four BPS disturbances with widespread reductions of solar PV output that occurred in the California Independent System Operator (CAISO) footprint between June and August of 2021. Each disturbance was categorized as a Category 1i event per the NERC Event Analysis Process and involved widespread reductions of active power output from solar PV resources in the Southern California area (specifically in areas of high penetrations of solar PV and wind resources). Two of these events also involved tripping of synchronous generating resources, and three involved some degree of distributed energy resource (DER) tripping or reduction. All initiating faults were normally cleared with proper protection system operation. This report references the Victorville, Tumbleweed and Windhub and Lytle Creek Fire disturbance all from 2021.

The report also references Alerts, Reliability Guidelines, White Papers, and Technical Alerts published resulting from a string of incidents from 2017 through 2022. The links to the original papers provide an in-depth look at four key focus areas including risk analysis, interconnection process improvements, sharing best practices and industry education and regulatory enhancements.