About This Metric
The purpose of this metric is to provide an indication of the relative performance of transmission protection systems, specifically protection system misoperations. Nearly all major system failures, excluding those caused by severe weather, include misoperations of relays or automatic controls as a factor contributing to the propagation of the events. Reducing the risk to reliability from relay and control system misoperations requires consistent collection of misoperation information by Regional Entities along with systematic analysis and correction of the underlying causes of preventable misoperations.
Metric Reporting Template
With the NERC System Protection and Control Subcommittee’s technical guidance, a set of specifications, including misoperation categories, cause codes and a Reporting Template for the regions to use in refining their processes to collect relay and control system misoperations information from their registered entities has been agreed upon. Quarterly, each Regional Entity sends the collected information (excluding Corrective Action Plan and technical contact information) to NERC for metrics analysis. To further help with the process, a set of common Questions & Answers (PDF) was developed.
Metric Definition Document
M-9 Correct Protection System Operations
