The Effects of Terminal Complexity and Redundancy on the Frequency and Duration of Forced Outages

The Mid-Continent Area Power Pool 230 kV and 345 kV bulk transmission terminal-related forced outages were analyzed in order to assess the difference in performance of four types of terminal configurations. Two terminal characteristics were recognized: complexity of protection/control and functional redundancy. The results demonstrated that the terminal configurations which are functionally redundant have a higher outage rate. but a lower average outage duration. The higher outage rate is due mainly to false trips caused by the complexity. The lower duration is achieved by exploiting functional redundancy. The partial breaker configuration, being the most complex and least redundant, had the highest overall unavailability. Forced related multiple outage event analysis was not part of this study.