Probabilistic transient stability studies using the conditional probability approach

A transient stability study of the Taiwan power system is performed using a probabilistic approach. The stochastic nature of prefault system loading conditions, as well as other initiating factors, such as the number of faulted circuits and the location and type of faults, was recognized during the compilation of the outage statistics of the Taiwan power system. Thus, a probabilistic stability index which takes these random characteristics of system faults into account is computed by using the concept of conditional probability. In addition, the contributions of various fault events to system instability are analyzed by using Bayes´ theorem. The effect of load-level uncertainties on stability indices is also examined