The substation fault diagnosis method based on the time constraint probability Petri net

There exist some difficulties in existing substation fault diagnosis when dealing with the alarm information misstatement, omission, relay protection, breaker malfunction and tripping and such uncertain information. Therefore, the author put forward a kind of Petri net based on time constraint possibility of substation equipment fault diagnosis method to solve the problem of the uncertainty of substation fault diagnosis. First, time interval back model is constructed to represent the time constraints in the process of failure, to modify the alarm information, and delete the alarm information which is not in conformity with the temporal constraints. Then use probability indicates protection and circuit breaker movement situation and further processing uncertain information in case to increase the rate of fault tolerance. Finally, the correctness and effectiveness of the method is verified by the example analysis.