What is Event Analysis?
Through the
Event Analysis Process (EAP), entities voluntarily work with NERC and their Regional Entities to review events on the BPS. The EAP provides a consistent approach to event analysis and a platform for sharing lessons learned with the industry. All lessons learned through the EAP are posted on the NERC website.
Loss of Bulk Electric System (BES) facilities (Category 1a): Unintended loss of three or more facilities from a common cause.
Remedial Action Scheme (RAS) misoperations (Category 1c): Failure or misoperations of a RAS.
System voltage reduction (Category 1d): System-wide voltage reduction of ≥ 3% for 15 minutes or more due to a BES emergency.
Islanding (Category 1e): Unintentional BES separation resulting in an electrical island ≥ 100 MW.
Loss of inverter-based resources (Category 1i): Non-consequential loss of 500 MW or more of inverter-based resources.
Loss of monitoring or control (Category 1h and 2b): Loss of monitoring or control capability for 30 minutes or more that affects an entity’s ability to make operating decisions.
Loss of interpersonal communication (Category 2a): Complete loss of interpersonal communication and alternative interpersonal communication for more than 30 minutes.
Loss of load (Category 2f and 3a): Loss of firm load for 15 minutes or more exceeding 300 MW for entities with previous year's demand ≥ 3,000 MW, or 200 MW for all other entities; or the unintended loss of ≥ 2,000 MW of generation.