1 – Antitrust Admonition

Presenter: Julia Matevosyan

2 – DWG Procedure Manual — S.-W. Kang

• ERCOT appreciates stakeholder support and addressed all comments on the DWG precision manuals.
• Draft DWG procedure manual posted on DWG website.
• PUCT decision on NPRR245 expected in September; effective date likely October 1.
• ROS approval sought on October 3, previously planned for September.
• Updated DWG manual available on the website as a draft for familiarization.
• ERCOT updated PMV and DMV tools for NPRR245 writethrough test.
• Tools are linked in previous meeting presentations and ERCOT model quality guide.
• Confirmations received from Jonathan on PMV and DMV tool updates with latest NOGRR245 test proposals.

3 – NERC Standards Update — FERC Order 901 (M. Henry, TRE)

• Brief update on NERC standards related to FERC order 901
• FERC directives to NERC in October 2023 to address IBR integration challenges
• Four focus areas: data sharing, model validation, planning, operational studies, IVR performance requirements
• Milestone 2 projects to be completed by November 4
• Three projects involved in Milestone 2
• Details on the first project: Disturbance monitoring equipment (2021-04) leading to PRC-028-1 standard
• PRC-024 version 5 IBR-related material moved to PRC-029, consensus issues
• Technical Conference held by NERC to gather feedback on PRC-029
• Workshop findings: difficulty meeting requirements with older equipment, technical challenges, and OEM feedback
• New standard PRC-030 asking entities to evaluate and mitigate issues
• New standards expected to be issued for final ballot
• NERC board may step in if consensus is not reached Q&A highlights
• John Schmall: Who drafts the revised PRC-029?
  Answer: NERC staff, driven with the standards committee.
• Ken Donohoo: Concerns about exceeding IEEE 2800 and legacy equipment.
  Answer: It’s acceptable if regional needs exceed NERC standards; legacy equipment considerations are being discussed.

Next steps

• NERC to issue a new standard for ballot with a quick turnaround.
• More outreach and timeline updates post-FERC approval.

4 – Draft Proposal for Advanced Grid Support Energy Storage Resource (F. Huang, ERCOT)

• Update on planned revision request; three documents posted: draft NOGRR, draft PGRR, and the pace framework report.
• Consultant recommended 11 tests for grid-forming technology; narrowed to seven proposed test requirements:
  • Flat start test
  • Small voltage disturbance test
  • Large voltage disturbance test
  • Frequency change & inertia response test
  • System strength test
  • Phase angle jump test
  • Loss of synchronous machine test
• Expected grid impacts: improved voltage/frequency response and stability, especially where advanced grid support storage is deployed.
• Applies first to energy storage resources; may extend to wind/solar later.
• New requirements will apply to storage with SGIS agreements signed on or after April 1, 2025.
• A work session may occur at the next IBRWG; stakeholders encouraged to comment before formal October submission.

5 – PFR from IBRs under “Deep” Curtailment (M. Cova Acosta – Vestas; Nick Miller – Hickory Ledge; All)

• Reviewed BAL-TRE frequency response context and defined zones.
• Main issue: IBRs often fail to provide PFR when heavily curtailed or stopped.
• Turbines fully stopped can’t meet ERCOT’s 16–60s PFR expectation without restart time.
• Two suggestions:
  • Add an exemption for this condition.
  • Set realistic expectations and telemetry to reflect actual capability (e.g., NTON/NTOFF).
• Additional limitation: technical minimum operating points; avoid frequent stop/start from minor frequency deviations (use low sustained limits or filtering).

6 – NOGRR245 Update (S. Solis, ERCOT)

• Commission review expected this month; internal drafts exist.
• Regional standards can exceed NERC as needed for ERCOT.
• New NOGRR will follow soon after approval; discussion in IBRWG for ~1 month, with key debates in ROS/TAC.
• Monthly updates to IBRWG planned.

7 – RoCoF & Phase Jump Measurement Discussion (M. Cova Acosta – Vestas; S. Solis – ERCOT; All)

• Measuring RoCoF/phase jumps during transients/faults can be unreliable.
• IEEE 2800 recommends averaging window ≥ 0.1s; ERCOT considering 0.5s.
• Phase angle jumps should not trip during faults; needs separate averaging considerations.
• Need for standardized methods across OEMs; transparency in ERCOT methodology requested.
• Plan for a working session to refine measurement windows and implementation.

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