Today’s LiveWire Spotlight assesses NERC’s latest Lessons Learned; a “teachable moment” where a unique type of Protection System Misoperation threatened electric system reliability.  In this case, a breaker failure relay protecting a BES main bus suddenly operated for no apparent reason and tripped six connected transmission lines.  After intense follow-up testing, the relay vendor identified the root cause as memory corruption attributed to a high-energy cosmic particle – which on rare occasion can flip a bit in a relay’s Random Access Memory (RAM) matrix.

Protection System Misoperations continue to be a leading cause of BES service loss and are among NERC’s top reliability concerns.  Severe penalties may be levied if an outage occurs, and it is found that an Operator did not act upon this Lesson Learned.