Research On Fault Diagnosis Method Of Microgrid Based On Hybrid Petri Net

With the continuous reform and innovation of electric power science and technology,electric energy has become a vital energy in the development of science and technology and digital life.The lack of fossil energy and the deterioration of ecological environment have put forward higher requirements for the sustainable use of traditional energy,and also make the development and application of microgrid become a research hotspot.In order to ensure the safe and stable operation of microgrid and the reliability of microgrid power supply,it has become an important task for the system to detect and locate the faults in the first time so as to provide convenience for subsequent fault treatment under the condition of a sudden microgrid fault happens.At present,the research of power grid fault diagnosis is mainly based on expert system,artificial neural network,analytical model and other methods.These methods are not suitable for the application of microgrid with changeable operation mode and diverse topology structure.With the efforts of experts and scholars,Petri net theory has been continuously developed and improved.It can describe and process discrete events graphically,and the reasoning process is simple and easy to understand.It has broad application prospects in the research of microgrid fault diagnosis methods.On the basis of analyzing and synthesizing the characteristics of the existing fault diagnosis methods for microgrid,this paper deeply studies the application of Petri net theory,analyses and discusses the existing fault diagnosis methods for power system based on simple Petri net,and summarizes the defect of the method through the analysis of examples.This paper Aiming at the defects of existing methods and the particularity of microgrid fault diagnosis,in order to improve the efficiency of microgrid fault diagnosis,reduce the search time and narrow the search scope,on the basis of current advanced Petri net system to propose a fault area search method based on colored Petri net,and then verify its adaptability by an example analysis,and then use Stateflow to do simulation test of searching result of the example analysis.Finally,on the basis of the above work,according to the characteristics of microgrid and its requirements of fault diagnosis,a hybrid Petri net is constructed by combining layered idea,improved adaptive fuzzy Petri net and fuzzy logic,and an object-oriented hybrid Petri net fault diagnosis method for microgrid is proposed.In the fault diagnosis model based on hybrid Petri net,the improved BP algorithm is introduced to train the parameters of the model and improve the accuracy of the diagnosis results.Finally,an example is given to verify the fault tolerance of the fault diagnosis method based on hybrid Petri nets.The method can give accurate diagnosis results under complex conditions such as single fault,multiple faults and information deficiency,etc.