CIGRE industry data underpins major system reliability improvement

David Roop, Director – Electric Transmission Operations & Reliability, Power Delivery Group, Dominion Energy explains how CIGRE membership resulted in improved customer reliability and reduced cost.

“About fifteen years ago we experienced increasing mechanism failures in our transmission circuit breakers. To find out why and how best to solve this problem we initially looked at peers in the U.S market using similar equipment with a comparable performance history. That led to a detailed review of our company’s maintenance policies for power circuit breakers and we discovered a training concern – many of our maintenance employees gained experience only from senior team members and a global maintenance process across our company was not in place. We developed extensive training opportunities for our maintenance employees, establishing stronger skills for each individual.  Despite this and, even after we increased our maintenance budget, we continued to experience a higher than expected mechanism failure rate.

That’s when we realised we had to look wider and the best way to that was to turn to CIGRE. One CIGRE Technical Brochure revealed significant performance differences between varying mechanism types and identified that the worst performing mechanism type worldwide was actually the type we had been using! We changed our specifications and began a replacement of all transmission circuit breakers on our system with mechanisms that were performing better, based on the CIGRE data. Today all our transmission circuit breakers, over 450 units, have been replaced accordingly. Since then we have experienced just one single mechanism failure.”