NERC MOD standards — Modeling, Data, and Analysis

Reference notes

NERC's MOD family (Modeling, Data, and Analysis) governs the data every operator and planner uses to study the bulk electric system. Every TPL planning study, every FAC interconnection study, and every PRC coordination study depends on accurate models of generators, transmission elements, loads, and control systems. MOD-032-1 is the cornerstone — the comprehensive data-submission rule. MOD-025-2 / 026-1 / 027-1 address generator-specific model verification. IEEE 2800-2022 is the increasingly central standard for inverter-based resource (IBR) modeling. Use Next → to walk through the family.

MOD family overview

• MOD-025-2 — Verification + reporting of generator real + reactive power capability
• MOD-026-1 — Excitation control + Power System Stabilizer model verification
• MOD-027-1 — Prime mover + turbine governor model verification
• MOD-032-1 — Comprehensive data submission rule (the cornerstone)
• MOD-033-2 — Steady-state + dynamic system model validation by PC
• Hyperscale relevance: co-located gen has direct MOD obligations · data-center load may have obligations depending on IBR content classification

MOD-032-1 comprehensive data submission

Three data categories the PC assembles for studies:

• Steady-state: network topology, equipment ratings, operating limits · line impedances, transformer ratings, gen capability curves, bus connections, load locations
• Dynamic: time-varying behavior · generator inertia, excitation models, governor models, PSS models, IBR control models
• Short-circuit: fault behavior · source impedances, transformer Z, generator subtransient + transient Z, breaker interrupting ratings

• R1: PC defines + publishes data-collection requirements (what, format, deadline)
• R2: registered entities (TO, GO, DP, LSE) submit on schedule
• R3: data must accurately reflect installed equipment (manufacturer specs, type-test, on-site verification)
• R4: update on equipment change or PC's review interval
• Industry formats: PSS/E raw + dyr files (PJM/MISO/SPP/CAISO/ERCOT) · PSLF (WECC) · PSCAD for IBR EMT

Generator-specific model verification (MOD-025/026/027)

• MOD-025-2: verify real + reactive capability against nameplate capability curve · planning studies assume full curve — bad models → unanticipated V/Q problems
• MOD-026-1: excitation control + PSS models per IEEE Standard 421.5 (model types ST1, ST3, ST6, AC8B, etc.) · must match installed equipment
• MOD-027-1: prime mover + governor models (steam, hydro, gas turbine) per IEEE 421.5
• IBR extension: standards being updated to cover inverter-based resources · plant-level controls + inverter fault behavior need different model structures

Inverter-Based Resource (IBR) modeling

• Why IBR is hard: synchronous-machine models well-understood after decades · IBR behavior dominated by inverter control software · varies widely across manufacturers + continues to evolve
• IEEE 2800-2022 — IEEE Standard for IBR Interconnection · technical performance: ride-through, frequency response, reactive capability, protection · being incorporated into NERC standards + RTO interconnection requirements
• IRPTF — NERC Inverter-Based Resource Performance Task Force · drives standards revisions extending to IBR
• IBR Registration Initiative: smaller IBR plants previously exempt now subject to NERC compliance (mid-2025)
• Modeling domain:
  • RMS-domain (PSS/E, PSLF) at ~4 ms step — traditional
  • EMT-domain (PSCAD) at μs step — required for IBR fast transients + harmonic interactions
• Hyperscale connection: data center PDU + UPS + switching power supplies create IBR-like behavior at the load itself

Hyperscale model-submission lifecycle

1. Initial submission: at interconnection — complete steady-state + dynamic + short-circuit models for co-located gen, data-center load with power-electronic content, BTM behavior
2. Verification (per MOD-025/026/027): installed equipment must match submitted models — via generator capability tests, excitation system commissioning tests, governor response tests, IBR type-test reports + on-site verification
3. Lifecycle maintenance: update on equipment change — controller firmware updates, breaker replacements, transformer retrofits, load profile changes · annual data refresh cycles typical

RTO data-portal integration

• PJM: Modeling and Analysis Working Group (MMWG) models for planning + study cases
• MISO: MISO Series Model
• CAISO: powerflow base case
• Each requires a different data format + submission interface

Risks of MOD non-compliance

• Direct penalty: up to $1 M / day
• Corrupted planning studies: fail to identify actual reliability risks → surprise operational events
• Operational events: voltage collapse, oscillations, ride-through failures caused by mis-modeled equipment

Why it matters for the AWS Grid Code Compliance Manager role

NERC MOD standards are the data backbone of grid reliability planning. Hyperscale facilities — especially those with substantial inverter-based content — must submit, verify, and maintain accurate models for the life of the asset. The compliance team must coordinate with operations, engineering, and the Planning Coordinator at every model-relevant change for 20+ years of operation. Get model data wrong and every downstream NERC obligation is corrupted.