Research On Fault Diagnosis Modeling Based On Petri Net And Its Application In Fault Diagnosis Of Wind Turbine

This paper makes a detailed analysis of both the modeling methods and featuresof the Fuzzy Petri Net and Fault Petri Net in fault diagnosis. Deficiencies are foundthat neither of them can completely solve the fault diagnosis problems.For example,Fuzzy Petri Net’s operation rules don’t reflect the inherent characteristics of thefault propagation, neither can they locate the fault. However, Fault Petri Net can notascertain the maximum transmission path of the failure and there can emergeconflicts through backward reasoning. Based on this, Fuzzy Fault Petri Net is putforward, which is more suitable for fault diagnosis. Its definition, the transitionoccur rules and the consequences of the occurence,as well as the fault reasoningalgorithm are proposed.It makes a great deal of progress in the fields of Petri Nettheoretical research and fault diagnosis applications.Based on the above theoretical research results, the object-oriented ideas basedon UML is adopted to achieve the Petri net modeling and the inference algorithm. Inthe beginning, the requirement analysis of the Petri net reasoning system prototypeis made. The functions include editing documents, viewing modules, establishing themodel of the Fuzzy Fault Petri Net, and the forward reasoning and result analysis.Therefore, the use case diagram of the system prototype is generated. After thefunctions distrubed, the class diagram is gained to shift from analyzing model todesigning model. And then the reasoning system prototype with general functions isestablished.Finally, the theory of Fuzzy Fault Petri Net is applied to the fault diagnosis ofwind turbine.Then by using reasoning system prototype, it is verified that thismethod is feasibily and correct. At the same time, it provides a theoretical basis andpractical solutions to deal with the wind turbine fault diagnosis and fault warningunder the complex environment.Generally speaking, the study results of this paper are as follows:1. After analysis of Fuzzy Petri Net and Fault Petri Net modeling method in faultdiagnosis, the concept of Fuzzy Fault Petri Net which is more suitable for fault diagnosis is proposed.2.Combining the dynamic characteristics of Fuzzy Fault Petri Net and faultmode of transmission, the modeling method and diagnostic reasoning algorithm ofthe Fuzzy Fault Petri Net are given.3.By using Visual Studio tools to develop the prototype of the Fuzzy Fault Petrinet modeling method and the reasoning system, the place, transition and input/outputarc object sets of database are established, then the object is achieved to add, delete,modify and drag at the interface, and do the basic reasoning.4. With fault propagation mechanism of the wind turbine gearbox, the FuzzyFault Petri Net modeling approach is applied to model and fault diagnosis,what ismore, the constructed system prototype is used to simulate it.