ERCOT’s Model Quality Testing (MQT) framework has become the defining benchmark for interconnection and operation of inverter-based resources (IBRs) in Texas. Between recent Planning Guide changes, the PGRR109 model review process, and stricter Dynamics Working Group (DWG) oversight, resource owners now face far tighter timelines and data expectations than ever before.
GridStrong helps developers, generators, and transmission operators automate these requirements—eliminating rework, missed deadlines, and compliance gaps.
Understanding ERCOT’s MQT Requirements
ERCOT’s DWG Model Quality Testing process ensures that every IBR’s dynamic model accurately reflects how the plant behaves in real life. To pass MQT, resource owners must demonstrate that their RMS (PSSE/TSAT) and EMT (PSCAD) models reproduce key control behaviors:
- Voltage and frequency ride-through
- Active and reactive power controls
- PLL, outer-loop, and momentary cessation logic
- Response to benchmark disturbances
ERCOT’s published MQT and VRT guidelines define testbench configurations, benchmark event cases, and pass/fail criteria—forming the foundation of every interconnection study and stability assessment.
The PGRR109 Model Review Gate
ERCOT’s Planning Guide Revision Request 109 (PGRR109) formalized how and when model reviews must occur:
- Pre-commissioning: From the Facility Information Summary (FIS) through Quarterly Stability Assessment (QSA) and Part-3 milestones.
- Post-commissioning: Whenever a modification changes plant response at the point of interconnection—such as firmware or control setting updates.
The result is a continuous validation loop: models must always match actual operating controls. Submissions include updated PSSE/TSAT/PSCAD models, complete MQT reports, and supporting plots—all uploaded through ERCOT’s RIOO platform.
What’s Changed Lately
1. DWG → ROS November Update (Nov 6, 2025)
ERCOT’s DWG report now ties stability assessment cycles directly to model submission windows—meaning projects that miss clean MQT submittals risk being deferred to the next review pass.
2. PDCWG October Briefing
The Planning and Dynamic Coordination Working Group (PDCWG) emphasized aligning models with measured frequency and voltage responses, particularly under AGC regulation and low SCR conditions.
3. MQT Failures Linked to Field Tuning (Sept 2025)
ERCOT reiterated that on-site AVR or Q-limit adjustments during Part-2 testing have caused repeated MQT/VRT failures. Coordination between field engineers and modelers is now a must.
4. PGRR109 Timeline Clarifications (Aug 2025 Workshop)
ERCOT’s latest workshop confirmed key turnaround times:
- ERCOT model review: 10–30 business days
- Optional TSP stability study: +90 days if triggered
These windows have direct commercial implications for projects targeting COD or NOGRR 255 compliance milestones.
Common Pain Points for IBR Owners
- Model redundancy: Separate RMS, TSAT UDM, and EMT files must stay aligned throughout the project lifecycle.
- Tight scheduling: Overlapping MQT, VRT, and PGRR109 reviews compress interconnection timelines.
- Post-tuning failures: Field modifications without model validation remain a leading cause of rework.
How GridStrong Simplifies ERCOT MQT Compliance
GridStrong’s compliance automation platform integrates ERCOT’s full modeling workflow—so you can validate, document, and submit faster.
1. Automated MQT Workflows
Run ERCOT’s DWG test cases, overlay PSCAD/PSS®E/TSAT plots, and auto-generate the official MQT report—all inside a single platform.
2. Model Version Control and Validation
GridStrong links your dynamic models directly to field configuration data, ensuring every update is traceable and consistent across studies.
3. PGRR109 Review Readiness
Prepares submission packages formatted to ERCOT templates, complete with overlays, benchmark comparisons, and email-ready documentation for dynamicmodels@ercot.com.
4. Event Data Integration
Tie modeled performance directly to recorded events for true model fidelity, aligning with both ERCOT and NERC PRC-028 / PRC-030 requirements.
Best Practices for Meeting ERCOT’s Model Quality Expectations
- Use ERCOT’s latest templates and include your MQT report in every RIOO submission.
- Plan for review slack: Assume at least 30 business days, and 90 if ERCOT triggers a TSP stability study.
- Lock field settings after model validation to prevent MQT/VRT inconsistencies.
- Maintain benchmark libraries using real event data for faster comparisons.
Why It Matters
ERCOT’s MQT and PGRR109 frameworks are now integral to Texas’s broader IBR reliability strategy. Together, they enable credible dynamic assessments, operational readiness, and alignment with national reliability standards—including upcoming NERC PRC-028 and PRC-030 compliance.
Talk to an Expert
GridStrong’s ERCOT compliance suite automates MQT testing, PGRR109 submissions, and ongoing dynamic model validation—reducing manual effort and keeping your interconnection on schedule.
Talk to an Expert to see how GridStrong can streamline your ERCOT model compliance process.
