ERCOT IBRWG Meeting Summary
Executive message: ERCOT is continuing to move IBR compliance from stated capability toward demonstrated, simulation-validated performance. The April 27 IBRWG materials focused on AGS-ESR testing, DMView/PMView tool updates, the PSSE v35-to-v36 transition, and broader NERC/industry standardization efforts. For developers, the practical implication is early model readiness, traceable MQT evidence, and tighter alignment between submitted models and actual plant controls.
(1.) Key technical updates from the meeting
(1.1) AGS-ESR requirements and testing expectations
ERCOT highlighted the implementation of approved AGS-ESR requirements under NOGRR272 and PGRR121, effective December 1, 2025. The updated DWG Procedure Manual clarifies requirements for AGS-ESR and mixed-technology facilities, including MQT test setups, required results, performance guidelines, and updated Unit Model Validation language.
- AGS-ESR facilities are expected to demonstrate voltage and frequency support through standardized simulation testing rather than high-level control descriptions only.
- For mixed-technology sites, only the portion of the facility subject to the new AGS-ESR performance requirement is evaluated against the new AGS-ESR tests; however, ERCOT may review terminal and POI quantities for the full facility to confirm capability.
- Required evidence will likely include test setup files, simulation output plots, and POI/terminal response quantities that clearly demonstrate compliance.
(1.2) DMView and PMView tool updates
ERCOT presented updated DMView v3.5 and PMView v3.5 workflows to support AGS-ESR testing. The updates appear intended to make test execution more consistent across PSS/E and PSCAD environments and to reduce ambiguity in test setup, configuration files, and plot generation.
- DMView examples showed INI-file driven test setup and case-file organization for AGS-ESR test scenarios.
- PMView examples showed the model implementation and test profile interface used to evaluate AGS-ESR behavior in PSCAD.
- ERCOT also noted internal automation scripts for PSCAD MQT runs, CSV consolidation, AGS-ESR plotting, and PSS/E-PSCAD overlay comparisons. These may be released externally in the future depending on interest and additional considerations.
(1.3) PSS/E v35 to v36 transition
ERCOT is transitioning dynamic model requirements from PSS/E v35 to v36. Version 36-compatible models should be provided by June 1, 2026, with earlier submission preferred. ERCOT also indicated that v35-compatible models will still be needed until the full v36 flat-start case build transition is complete.
- There are no grid-forming generic models available in PSS/E v35, so ERCOT may allow flexibility for v35 User Defined Models (UDMs) during the transition for FIS/additional studies.
- Differences may occur between v35 UDM and v36 generic model implementations, so model response alignment needs to be checked early.
- ERCOT and the relevant TSP will expect reasonable correspondence between UDM and v36 generic model responses before accepting the models for study use.
(1.4) NERC standards and industry coordination
Texas RE summarized active NERC standards activity related to FERC Order 901 and IBR performance. Key items included ride-through revisions under PRC-029-2, EMT modeling, model/data verification, system model validation with IBRs, uniform IBR modeling, and planning/operational study updates. ESIG/DOE i2X updates also emphasized grid-forming inverter implementation, interconnection study harmonization, commissioning practices, and model validation.
