Evaluation of power system cascading outages

The indices, models and algorithms of evaluating cascading outages in power systems are proposed in this paper. At first, four deterministic and two probabilistic indices are defined for evaluating the cascading outages. These indices can reflect the practical distribution of the loss load and the severity of the failure. Uniting the network configuration with bus schemes of power substations, the cascading model of power systems is set up subsequently. In order to take into account the effect of protection systems, a new reliability model of protection systems is presented based on the fact that faults of protection systems can be reflected by the actions of breakers. An efficient algorithm is developed based on the above models, which incorporates all causes of cascading faults and achieves quantitative evaluation of power systems cascading faults. The algorithm includes five parts: fault analysis of bus station, trace of the network topology, judgment of the network connectivity, evaluation of system states and statistic of indices. In order to improve the computation efficiency, several techniques are adopted in the assessment. Cases study indicates that the presented approach can find the bottleneck of the network and discover the hidden failure of power systems.