Evolving IBR Interconnection Requirements: MISO's Enhanced Modeling Standards

Driven by the ever-increasing adoption of Inverter-Based Resources (IBR) and customer demand becoming more reliant than ever on power electronics, the regulatory landscape governing the IBR interconnection processes continues to rapidly evolve.

Recent NERC Alerts[1] and increased attention to modeling accuracy through FERC Orders 2023[2] and 901[3] have identified significant inconsistencies in the modeling accuracy and analytical consistency when interconnecting new IBRs. These regulatory developments have prompted MISO to propose changes[4] to the types of models they will require as part of the Generation Interconnection Process for IBRs beginning in mid-2026.

These changes come on the heels of the February 2025 updates to PSCAD model testing requirements in MISO, which established mandatory compliance with Revision 13 of the MISO PSCAD Model requirements[5].

The changes proposed will require Interconnection Customers looking to develop IBRs in the MISO footprint to provide a modeling package at the time of application, as shown below:

Mandatory Performance Testing Protocols

To ensure that these required models accurately represent the IBR being developed, MISO has also proposed inclusion of performance testing requirements, encompassing:

• Initialization Testing
• Balanced Fault Ride-Through
• Small Voltage Disturbance
• Small Frequency Disturbance
• High Voltage and Frequency Ride-Through
• Low Voltage and Frequency Ride-Through
• Protection Verification, and
• Short Circuit Ratio (SCR) Analysis

Model submissions undergo comprehensive review during MISO’s Application Review process. They will also require updates as changes to proposed facilities and technologies are encountered throughout the Definitive Planning Phase (DPP) and prior to GIA execution. In addition, final as-built models must be submitted within 60 days of an IBR’s Commercial Operation Date (COD), with ongoing updates implemented as needed post COD.

At EPE, our dedicated team of experts continue to follow these developments closely through the MISO Interconnection Process Working Group (IPWG) and Planning Advisory Committee (PAC). Whether you are looking to understand how these changes impact timelines and requirements for your project, or to accurately undertake the proposed testing in anticipation of an application, EPE stands ready to support interconnection requests of all types. To find out how our team can help you navigate the ever-changing landscape of generation interconnection processes, contact us using the form below.

MISO Interconnection Process Working Group: Next meeting September 3, 2025

MISO Planning Advisory Committee: Upcoming meetings on August 27, 2025 and  October 8, 2025

[1] NERC Alert Level 2 - Inverter-Based Resource Model Quality Deficiencies.pdf

[2] Order No. 2023 | Federal Energy Regulatory Commission

[3] FERC Order No. 901 Summary of Milestone 2_071224.pdf

[4] MISO IBR Interconnection Modeling Requirements

[5] PSCAD-Model-Requirements-Rev.-13-Feb-2025-1.pdf