NERC has filed five proposed reliability standards with FERC, completing an occasionally eventful development process and taking the final step toward satisfying the commission’s mandate to develop reliability requirements for inverter-based resources. 

The standards submitted Nov. 4 address the second milestone in FERC Order 901, issued Oct. 19, 2023. According to NERC’s IBR work plan developed this year, Milestone 2 standards cover performance requirements and post-event performance validation for registered IBRs and were to be submitted by Nov. 4, 2024. Standards covering data-sharing and model validation for all IBRs are due by 2025, and planning and operational studies requirements for all IBRs are due by 2026. (See NERC Submits IBR Work Plan to FERC.) 

The following standards, and their implementation plans, were part of the Milestone 2 filing: 

• • PRC-024-4 — Frequency and voltage protection settings for synchronous generators, Type 1 and Type 2 wind resources, and synchronous condensers.  

• • PRC-028-1 — Disturbance monitoring and reporting requirements for inverter-based resources.  

• • PRC-002-5 — Disturbance monitoring and reporting requirements.  

• • PRC-030-1 — Unexpected inverter-based resource event mitigation. 

• • PRC-029-1 — Frequency and voltage ride-through requirements for IBRs. 

NERC also submitted a new definition of the term “inverter-based resource” for inclusion in the ERO’s Glossary of Terms. 

In the implementation plans for the standards, NERC requested that FERC set the effective date for PRC-024-4, PRC-030-1, and PRC-029-1 as the first day of the first calendar quarter that is 12 months after the effective date of the commission’s approval order. Because PRC-029-1 is a prerequisite for PRC-030-1, the ERO suggested an alternative effective date could be the first day of the first calendar quarter that is 12 months after the effective date of the commission’s approval order for PRC-029-1. 

For PRC-002-5 and PRC-028-1, NERC proposed the standards become effective on the first day of the first calendar quarter after the effective date of FERC’s approval order. The ERO said a “relatively short implementation period is necessary to establish … PRC-028-1 as the standard governing disturbance monitoring requirements for IBRs.” 

All of the draft standards were approved by NERC’s Board of Trustees at a special meeting Oct. 8, held after PRC-029-1 received industry approval in a ballot that ended Oct. 4. The standard was the last of the five to pass its formal ballot, and the standards drafting team’s inability to get PRC-029-1 across the finish line led the board in August to invoke for the first time its authority to streamline the ERO’s stakeholder approval process. 

Following the board’s August decision, NERC’s Standards Committee held a technical conference in September to hear feedback from industry, which the drafting team then used to revise the standard. It was this revision that finally passed the industry ballot in October. 

After the board voted to submit the five standards to FERC, NERC Vice President of Engineering and Standards Soo Jin Kim told trustees the technical conference turned out to be a big help identifying issues that had held industry back from supporting PRC-029-1. She suggested that when developing the Milestone 3 standards for next year, NERC will call for similar gatherings to “get ahead of … the technical issues” so the drafting teams can handle them proactively.