As the first link of power system failure emergency treatment

fault section estimation plays an important role in power system online control operation. Since the existing Petri net based fault diagnosis method does not make full use of the timing information and temporal reasoning process is complicated and time-consuming

a fault diagnosis method based on fuzzy time Petri net is proposed. Firstly

a time interval is set for each place and transition of the Petri net model to describe the timing constraints of the alarm information. Then related reasoning operation of the confidence probability and the timing constraint is defined. And based on the model structure

the hierarchical reasoning process of the fuzzy time Petri net is established. The reasoning process can be used to infer the confidence probability of the component failure as well as its time point constraint. Finally

the simulation results show that the proposed method can quickly determine the faulty components with strong fault tolerance. The diagnosis results are correct and reasonable

which can make correct evaluation of the alarm information.