Studies on models and algorithms of reliability evaluation for cascading faults of complicated power systems

The studies of models and algorithms for evaluating cascading faults in complicated power systems are given. Combining the connection diagram of the network with bus schemes of the power substation, the cascading model of power systems is set up firstly. In order to take the effect of protection systems into account, a new reliability model of protection systems is presented because their faults can be reflected to the actions of breakers. Moreover, an efficient algorithm is developed based on the above studies, which incorporates all causes of cascading faults and achieves quantitative evaluation of cascading faults of complicated power systems. The algorithm includes five parts: fault analysis of substation, the trace of the network topology, the judgement of the network connectivity, the evaluation of system states and the statistic of indices. Calculations for the test system indicate that the evaluation of cascading faults in complicated power systems can find the unsubstantial parts of the network and discover the hidden trouble of power systems. The computation results of IEEE-RTS show the validity and efficiency of the method.