Intelligent Fault Diagnosis Of Power Electronic Device

With the rapid development of power electronics and continual emerging of novel power electronic devices, power electronic equipments have been increasingly applied to all aspects of industry and living. The requirement of its maintainability is also more and more important. Because there are many devices in these circuits of high voltage, strong current systems, one will take much time and make many efforts to deal with it using normal fault diagnosis methods. Aiming at the own characteristics of fault, new technologies such as artificial intelligence, neural network, wavelet analysis, etc have been successfully used to fault diagnosis of power electronics. Intellectualized automatic fault diagnosis method has the advantage of rapid analyzing and localizing the fault, cutting the stop time, increasing the efficiency and reducing the loss.The research on failure feature extraction and failure to identify plays an important role in developing and improving the intelligent fault diagnostic. These signal feature vectors of various states about voltage and current of power electronic device, which are extracted by using the wavelet packet energy method, are integrated as the input vectors of the neural network failure classifier, identified and diagnosed various faults by the neural network classifier. The result of the simulate experiment with the main circuit of electronic power electronic rectifier device failure as an example, shows that the method can deal with the location of fault diagnosis rapidly and accurately without mathematical model.The software system design of fault diagnosis of three-level inverter device are realized by using these theories of wavelet and wavelet packet analysis, neural network, system identification and so on. The Visual diagnostic system is designed by direct using the GUIDE (graphical user interface development environment) of MATLAB. It has realized one design of the Interface and function. The tests results show that the fault diagnosis system have many advantages of high rate of fault diagnosis, diagnosis rapidly, operate simply and strong practical.