Abstract
This investigation was commissioned by the Office of Electricity of the Department of Energy in response to reviewing the NERC State of Reliability report. The study is an attempt to proactively address electric utility industry needs.
“Monitoring, analyzing, and tracking trends in Protection System Misoperations are critical to improve BES reliability. Historically, Protection System Misoperations have exacerbated the severity of most cascading power outages.” [1]
The NERC misoperations data shows that unnecessary trips are by far the leading category of reported misoperations and that a majority of misoperations are those of line protection packages. A significant number of mis-operations are tied to microprocessor relays. Approximately one quarter of reported mis-operations are due to incorrect settings and another one quarter of misoperations are due to relay failures/malfunctions and communication failures.