The Fault Diagnosis Of Electric Power Systems Based On Fuzzy Petri Nets

Expert System is commonly used in Transmission Power System FaultDiagnosis. But it is incompentent for large-scale online Power System FaultDiagnosis for its slow consequence and hardness to maintenance. Inferd based onPetri Nets, the Power System Fault Diagnosis can effectively be speeded up, whichtransfer the searching and matching process to matrix calculation process. Scholarstried resently to applied Petri or fussy petri nets to transmission power system faultdiagnosis.For example, method of establishing all models of elements in the systemhas the scarcity of universality and inconvenience maintenance.Method ofestablishing universal models went wrong when fault informations is insufficient,namely lack of error tolerance.A new approach of fault diagnosis for power transmission system based onFussy Petri nets is presented. Models of transmission line, transformer and busbarare established. Orientation area is minished by searching fault area.Then theelement fault in the erea is judged by the way of fussy Petri nets. The regulation ofFault and uncertainty problem are key points of accuracy and error tolerance in FaultDiagnosis.Therefore,the regulation of Fault of transmission line, transformer andbusbar has been improved in this paper. Setting the initial identifier of fussy Petrinets, action informations provided by SCADA system are described with largeprobability, and the ones not provided by SCADA are compensated using smallprobability. The technique can diagnose when informations are insufficient. Thetechnique is validated by simulation in four machines system.It is proved to bestrong uinversal and error toleration, with easy maintenance and modification.