Uncertainty Assessment Method of Power System Catastrophic Accidents

The component long-term failure and severity indices used in existing methods can not present time-varying characteristics when we assess the catastrophic event occurring in the power grid. A new method is presented in this paper based on uncertain measure. The credibility measure and global fuzzy security index are used to represent the possibility and severity of cascading failures. The N-l contingency was taken as the initial fault, and the hidden failure model and the ultimate catastrophic accident sequences were obtained in each simulation layer. The simulation results have shown that this method is accordant to the practice and it is with better accuracy, validity and feasibility.