ERCOT filed comments on NPRR1234 and PGRR115, introducing a new concept requiring updates in protocols.
Clarified definition for 'initial energization' related to generation resource interconnections, making it applicable to both new and modified resources.
Introduction of a new defined term, 'Transmission service bus,' to address maximum load criteria of 1000 megawatts from a single bus.
Comments address load commissioning plans, clarifying requirements and stability assessments.
Clarifications on load inclusion in QSA, ensuring it's tied to loads undergoing commissioning processes.
Obligations for TSPs specified regarding submission and updating of dynamic load models.
TSP compliance clarification related to customer behavior and transmission system limitations.
Discussion around the maximum allowable load from a single transmission point due to frequency stability concerns.
Two-pronged approach: introducing a load limit of 1000 megawatts from a single point and planning criteria to prevent losing more than 1000 megawatts in a single contingency.
Addressing feedback from entities like ERCOT Steel Mills and Oncor to incorporate suggestions into ERCOT's revisions.
Planning further analysis to potentially adjust the 1000 megawatt limit based on study outcomes.
Comments on some proposals, such as AEP's, were considered but not largely adopted due to differing approaches.
Requests for more review time before finalizing PGRR115 to ensure all stakeholder concerns are considered.
6 - PGRR119 – PGRR119, Stability Constraint Modeling Assumptions in the Regional Transmission Plan - PLWG
ERCOT planning clarified that the reliability margin mentioned in OPUC comments is not intended to be created anew in the RTP process, but rather to be used consistent with current operating procedures.
Alex Miller from EDF discussed the misunderstanding around the modeling of operating limits, emphasizing the modeling should reflect real-world limits and not just posted limits.
There was discussion on whether this PGRR is intended to capture similar concepts as in NPRR1070, specifically about modeling GTCs as they occur in reality.
ERCOT planning confirmed the intention to apply real-world stability limits and address similar concerns as in NPRR1070.
Alex Miller suggested including the impact of outages on D rates in the PGRR to improve clarity.
ERCOT planning explained ERCOT's discretion in applying additional analysis and benefits under PUC substantive rule, relating to outage-related benefits.
There was a proposal for offline discussions to further explore methodologies for modeling outages related to GTCs.
ERCOT's filed comments for NPRR1247 highlighted a white paper addressing weather uncertainty and transmission outages, though it wasn't specific to stability constraints.
It was noted that GTCs are uniquely challenging within ERCOT, requiring clarity for stakeholders about modeling processes.
Discussion on ERCOT's different activation procedures for IROL and SOL based on stability limits, with reliability margins noted as 10% or 15% depending on the limit type.
The PGRR119 was tabled previously pending comments, and OPUC's comments were discussed with a view to move the discussion forward in ROS.
There were thoughts on possibly refining language for transparency and clarity, with Alex intending to file written comments if needed.
Series compensated circuits: Discussed the ownership and installation timelines, highlighting TSP and non-TSP owned locations.
Explanation of SSO: Defined subsynchronous phenomena, including SSR, SSCI, and SSFR, and outlined mitigation efforts.
Past SSR events: Reviewed occurrences since 2009, including forced outages and mitigation attempts, particularly in South Texas.
PGRR120 proposal: Aims to prevent new generation projects from interconnecting in a manner that renders them radial to a series capacitor.
Impact on existing projects: Clarified the effect on ongoing projects and the process for new and existing projects, potentially hindering some from continuing if screen checks are not completed in time.
Real-time SSO mitigation: ERCOT's ability to prohibit operations if real-time SSO is detected.
Project screening and check stage: Emphasized on topology checks as part of the interconnection process to ensure compliance with the PGRR.
Discussion on future transmission fix: Debated if TSPs should seek transmission solutions to allow new generation connections despite series caps.
Consideration of a working draft approach to revise sections of the planning guide during each meeting.
Discussion on managing workload by revising sections one at a time, particularly the data and modeling section with numerous load references.
Bob Wittemeyer suggested a slower approach by revising the wording with each PGRR revision instead of an overall review.
Alex Miller inquired about the frequency of load references and the areas needing adjustment in the planning guide.
Aaron Gutierrez discussed different revision request options: PLWG could submit a request, draft could be sent to ROS, or a market participant could sponsor it.
Concerns about potential length and complexity of a full planning guide revision were discussed, with examples of similar past processes.
Consensus to proceed by addressing one section at a time in meetings to ensure manageability and currency of changes.
The possibility of scheduling discussions at the end of the agenda to allow participants to opt out if desired was suggested.
