A conditional probability approach to the calculation of frequency and duration indices in composite reliability evaluation

The authors describe a new methodology for frequency and duration (F&D) assessment in composite generation and transmission reliability evaluation. The proposed approach uses the concept of conditional probability to characterize the contribution of each component to the frequency indices, and allows the calculation of F&D indices at both system and bus level. The algorithm is easy to implement, and requires the same computational effort as the estimation of the system loss of load probability (LOLP) and the system expected power not supplied (EPNS) indices. Case studies with utility-derived systems are presented and discussed