Meeting Summary - 04/16/2025 RIWG Meeting

▶️1 - Antitrust Admonition

▶️2 - RIOO-Update

ERCOT-RIWG-2025-April-RIOO-1.pdf

• Introduction of high level changes to the RIOO application currently in production.
• New questions added to the substation panel to capture information on industrial generation facility designation, applicable for private use networks.
• For operational generators, default selections applied for the new questions.
• A new question introduced on the unit details panel to capture self generator PUCT registration status, required on UIS but not on URS.
• Addition of a radio button in devices, MLSE, and MPT data panels to allow skipping the relay loadability rating if not known.
• Label change on the unit solar inverter panel for clarity, renamed to 'base MVA for transformer in MVA'.
• New SSR required flag added for the INR TSP view and ‘TSP key milestones’ tab.
• Changes related to the load resources on the RIOO-RS side based on feedback, with stopped LRs hidden on the form but can be selected to view the data.
• Confirmation that the updates are currently live in production and were released as part of R3.

▶️3 - NOGRR245 Update

RIWG_April_2025_NOGRR245_Update.pdf

• The NOGRR245 deadline to submit extension or exception requests was moved to April 15, 2025.
• Existing units must complete maximization by December 31, 2025.
• Different deadlines for frequency and voltage ride-through extensions: frequency by December 31, 2027, and voltage by December 31, 2028, depending on ERCOT granting the extension.
• ERCOT is currently validating and reviewing submitted data and will develop a scope for the exception process by July-August 2025.
• NOGRR245 exception studies are planned for September-October, with notifications in November-December 2025.
• The exemption process timeline might adjust based on rulemaking from the PUC and the number of submissions received.
• Incomplete submissions must be addressed within ten business days upon notification from ERCOT.
• ERCOT's decision on extension requests to come within 180 days, with options to notify of extended review timelines if necessary.
• Participants can appeal ERCOT's decisions to the PUC.
• Approximately 500 resources intended for maximization by December 31, 2025, with various extension and exemption requests noted.
• Obligations for resources not submitting exception/extensions by April 15 include meeting frequency and voltage ride-through requirements by December 31, 2025, or synchronization/operation dates.
• Clarification that requirements apply only to transmission connected resources, not distribution connections.

▶️4 - Subsynchronous Ferroresonance Issues

• Verbal update on subsynchronous ferroresonance (SSFR) concerning interactions between main power transformers and series capacitors.
• SSFR has become more prevalent and poses risks during backfeed energization when transformers are brought online.
• A current issue is the late completion of SSR studies impacting project timelines.
• Consideration for conducting SSR studies before part one of backfeed energization.
• Installing protection relays on transformers is not an ideal solution due to ride-through requirements.
• Recommendation for using transformers with higher saturation curves and early SSR studies.
• Questions arose regarding inverter instability with shunt capacitors, responsibility of resource entities to consider such interactions.
• Information available on locations of series capacitors within ERCOT through previous presentations and MIS access.
• SSFR issues typically arise with radial connections or plants tapping serious compensated lines.
• Guidance on preferable saturation curves suggests above 1.2 per unit for transformers.
• Technical note: Subsynchronous currents can saturate transformers easily due to slower rate of change of current.

▶️5 - Dynamic Models – Power Plant Controller Issues

Templates-and-Declaring-the-PPC.pdf

• Discussion on the importance of submitting a proposed modification request before changing field settings, following ERCOT's Planning Guide 5.5(6).
• Introduction of the updated dynamic model template, due for submissions starting June 1, 2025.
• Focus on issues with interconnecting entities selecting power plant controllers late in the process, causing problems if the controller does not pass MQT tests.
• Announcement that starting next week, entities must declare their power plant controller when submitting a model.
• Clarification that models submitted and accepted without declaring a power plant controller won't need updates, but any new submissions must include this information.
• Emphasis on the potential need for restudy if declared models differ significantly from earlier submissions.
• Discussion on the importance of ensuring the power plant controller can pass all required tests and matching the declared performance in later stages.
• Concerns raised on communication delays affecting the dynamic reactive response of power plant controllers.
• Highlighting the need for accurate PSCAD modeling accounting for data measurement and command update constraints.
• Consideration of disallowing generic models in PSCAD due to their limitations in accurately reflecting site-specific constraints.
• Encouragement of accurate submissions taking into control speeds and communication lags.

▶️6 - Running AVR, PFR Tests in MQT

Running-AVR-PFR-Tests-in-MQT.pdf

• Discussion on running Automatic Voltage Regulator (AVR) and Primary Frequency Response (PFR) tests within Model Quality Tests (MQT).
• Currently a recommendation, but may become a future requirement.
• Issues identified where tuning during AVR tests affects MQT results, leading to non-compliance with voltage ride-through requirements.
• Recommendation to model AVR and PFR performance during MQT to ensure compliance before entering the Queue Service Agreement (QSA).
• Suggested short circuit ratio of about five, as detailed in the DWG procedure manual, section 3.1.5.8.
• ERCOT will review AVR and PFR test simulations submitted in MQT and provide feedback.
• No current impact on QSA acceptance, but recommended due to existing commissioning issues.
• Discussion on hardware suitability—if unable to meet both AVR and MQT requirements, the hardware may be inappropriate.
• Plants often delay AVR testing until online, leading to excessive adjustments; early simulation advised.
• Acknowledgment of plant-specific constraints and real-world limitations do exist.
• Emphasis placed on early verification of control and hardware capability.
• Acknowledgment that performance requirements are based on grid stability necessities.
• Difference in control adaptability discussed between wind facilities (typically more adaptable) versus solar and battery facilities.

▶️7 - GINR Topics

ResourceIntegrationWorkshop_GINR_Topics_04162025.pdf

• May 1 QSA deadline: All requirements must be met by May 1, 2025. The 45-day deadline for projects is March 17.
• EPS meter design proposal needs to be submitted before ERCOT approves full registration data. This affects projects aiming for future production load dates.
• New EIA reporting requirement: ERCOT must submit EIA-930A, detailing generator inventory. Three new EIA fields will be added to RIOO-IS and RIOO-RS starting April 24, 2025.
• EIA fields: Recommended completion before full registration data approval for projects without approved production load dates. Proposing mandatory inclusion in registration glossary revision.
• Clarification on procedures: EPS meter design proposal must be submitted 90 days before production workday, not just prior to PLD.
• Discussion on EIA-860 form: Completion depends on certain criteria, such as SGIA assigned notice to proceed.
• NPRR1272: Update on voltage support and private use network revision request.
• Commissioning requests for parts 1-3 must be submitted to the designated commissioning request inbox.
• There are over 2,000 generation interconnection requests totaling about 405 gigawatts. Small generation consists of 26 non-model ready and 50 model-ready projects.
• For queries, reach out to the resource integration department at ResourceIntegrationDepartment@ercot.com.
• Next meeting is scheduled for June 10, 2025.

8 - Other Topics

• Not Discussed

▶️9 - Adjourn