NOTICE DATE: May 2, 2025

NOTICE TYPE: W-A050225-01 Operations

SHORT DESCRIPTION: Requirement to submit dynamic models compatible with PSS/E version 36 prior to June 1, 2026

INTENDED AUDIENCE: ERCOT Resource Entities and Interconnecting Entities

DAYS AFFECTED: June 1, 2026

LONG DESCRIPTION: At the May 1, 2025, ROS meeting, the Dynamics Working Group (DWG) chair presented a tentative plan to use PSS/E version 36 for the development of DWG base cases starting in 2026. This transition from PSS/E version 35 to version 36 will require that Resource Entities and Interconnecting Entities submit dynamic models for their facilities that are compatible with PSS/E version 36 prior to June 1, 2026. According to the PSS/E version 36 release note, a key feature of version 36 is the ability to create PSS/E Version Independent (VINDP) dynamic linked library (dll). This means that dynamic user-defined model (UDM) DLLs created using PSS/E version 36 will be compatible with all future versions of PSS/E, offering greater flexibility and long-term usability.

Resource Entities and Interconnecting Entities that have equipment that is represented with standard PSS/E library models are not expected to need to submit updates for compatibility with PSS/E version 36.

Resource Entities and Interconnecting Entities that have equipment that is represented with user defined dynamic models are required to submit updated models to ensure compatibility with PSS/E version 36.

Resource Entities and Interconnecting Entities shall continue to submit dynamic models compatible with PSS/E version 35 until the transition to PSS/E version 36 is complete. The transition will be considered complete after DWG has approved a set of base cases that are compatible with PSS/E version 36 and the DWG Procedure Manual is updated to identify PSS/E version 36 as the current planning model software.

ACTION REQUIRED: Please submit any necessary dynamic model updates for compatibility with PSS/E version 36 via Resource Integration and Ongoing Operations (RIOO) attachment prior to June 1, 2026. Model quality tests in accordance with Planning Guide Section 6.2(5)(c) should accompany updated models to confirm proper model response. File names should reflect the associated PSS/E version as necessary.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

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