EOP-004-5 revises the event reporting framework in EOP-004 to better address reliability risks associated with Inverter-Based Resources (IBRs). The most significant change is the addition of a new reportable event category for unexpected IBR generation loss. Unlike the prior generation-loss reporting threshold, which focused on larger disturbances involving conventional generation, the new IBR-specific threshold is intended to capture smaller but operationally significant IBR disturbances that may otherwise go unreported.
The revised standard also introduces a defined 30-second evaluation window following a disturbance. This time-based element is important because IBRs can respond rapidly to system conditions, and material reductions in real power output may occur over short timeframes during normal operation such as due to weather or other operational decisions. By requiring entities to evaluate aggregated pre- and post-disturbance telemetry over this smaller 30-second period, EOP-004-5 is designed to improve visibility into IBR performance during grid events and support more consistent identification of reportable disturbances.
A key purpose of the revision is to strengthen the connection between event reporting and disturbance data availability. PRC-028 requires applicable IBR owners to retain disturbance monitoring data for a limited period. Prompt reporting under EOP-004-5 helps ensure that the North American Electric Reliability Corporation (NERC), Regional Entities, and other appropriate organizations are alerted to qualifying IBR events soon enough to request and obtain the underlying disturbance data before the retention period expires. This improves the ability to perform timely event analysis, identify recurring performance issues, and support corrective actions that enhance Bulk Power System reliability.
Overall, EOP-004-5 represents a targeted update to the existing event reporting standard. It recognizes that IBR behavior during disturbances differs from conventional synchronous generation and that smaller, faster IBR-related events can still have reliability significance. The added IBR reporting threshold along with its shorter assessment period are intended to improve timely awareness, preserve access to short-retention disturbance data, and give NERC and other reliability organizations the information needed to assess IBR performance and emerging system risks.
