May 13, 2026|News

Understanding MOD-026-2: Expanded Modeling Obligations and Compliance Timeline

By John Zong

Effective April 1, 2026, NERC MOD-026-2 is a new reliability standard that significantly expands upon the retired MOD-026-1 and MOD-027-1 standards. MOD-026-1 and MOD-027-1 historically covered dynamic model validation requirements for positive sequence models (PSSE/PSLF/TSAT).

Driven by FERC Order No. 901, MOD-026-2 mandates that IBR Owners submit both positive-sequence and electromagnetic transient (EMT) dynamic models — verified and validated against actual field measurements or staged tests.

How Will MOD-026-2 Affect IBR Owners?

New: EMT Model Required: IBR owners must now submit a verified and validated EMT model (e.g, PSCAD) in addition to the positive-sequence model.
New: Large-Signal Benchmarking: Models across different platforms (e.g, PSCAD and PSSE) must be benchmarked using large-signal disturbance tests.
Mandatory Field Testing: Model validation must compare simulated vs. measured responses from staged tests or system disturbances — covering both active power/frequency and reactive power/voltage excursions.
10-Year Validation Cycle: Models must be fully reverified and revalidated at least every 10 years, and within 180 days of any hardware, firmware, or control-mode change that alters dynamic response characteristics.

Why Partner with EPE?

End-to-End Service: From test plan to final compliance report — one team, one contract, no coordination gaps.
PSS/E, PSLF, TSAT & PSCAD Experts: Expertise in all simulation platforms used by regional Transmission Planners and Planning Coordinators.
OEM Coordination: EPE’s team of experts works directly with turbine and inverter OEMs to obtain and validate proprietary PSCAD models.
Compliance Calendar Management: Our team tracks your R2, R3, and R4 milestones — so you never miss a model submission deadline.

To find out how EPE’s team of compliance experts can help you meet the new MOD-026-2 standards efficiently and strengthen reliability in the process, contact us today using the form below.

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About the Author

John Zong

John Zong serves as the Director of NERC Technical Services at EPE, bringing expertise in NERC compliance testing and power generator studies across various technologies, including gas, steam, hydro, and inverter-based systems. His hands-on experience spans on-site testing, AVR/PSS tuning, protection coordination studies, generator modeling, and industrial load modeling for clients across North America, Asia, and the Middle East.

John's in-depth knowledge of transmission planning and operations is bolstered by his extensive work conducting system impact analyses and operational studies within utility environments. A licensed Professional Engineer in both the U.S. and Canada, John also lends his expertise as an advisor to multiple NERC Standard Drafting Teams, ensuring his insights contribute to shaping the industry's regulatory framework.

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How Will MOD-026-2 Affect IBR Owners?

New: EMT Model Required: IBR owners must now submit a verified and validated EMT model (e.g, PSCAD) in addition to the positive-sequence model.
New: Large-Signal Benchmarking: Models across different platforms (e.g, PSCAD and PSSE) must be benchmarked using large-signal disturbance tests.
Mandatory Field Testing: Model validation must compare simulated vs. measured responses from staged tests or system disturbances — covering both active power/frequency and reactive power/voltage excursions.
10-Year Validation Cycle: Models must be fully reverified and revalidated at least every 10 years, and within 180 days of any hardware, firmware, or control-mode change that alters dynamic response characteristics.

Why Partner with EPE?

End-to-End Service: From test plan to final compliance report — one team, one contract, no coordination gaps.
PSS/E, PSLF, TSAT & PSCAD Experts: Expertise in all simulation platforms used by regional Transmission Planners and Planning Coordinators.
OEM Coordination: EPE’s team of experts works directly with turbine and inverter OEMs to obtain and validate proprietary PSCAD models.
Compliance Calendar Management: Our team tracks your R2, R3, and R4 milestones — so you never miss a model submission deadline.

To find out how EPE’s team of compliance experts can help you meet the new MOD-026-2 standards efficiently and strengthen reliability in the process, contact us today using the form below.