On-line Fault Diagnosis Of Power Electronic Device Based On Virtual Instrument

In the field of aerospace power,power electronic devices usually as the power supply section play the important role in the test drive platform.Once the fault occurs,the equipment will halt causing economic losses or it may even case heavy casualties.Therefore,a set of on-line monitoring and fault diagnosis system is designed to ensure the normal operation of the system and the timely investigation after the failure.This paper starts from the following points:First of all,aiming at the drawbacks of the original test platform for signal measuring point dispersion,traditional instrument supervision,manual reading records,through field research,the design of hardware acquisition system with high precision,PXI bus multi thread based on virtual instrument,drawing collection electrical wiring system diagram by using EPLAN software developed sensor switch box and test cabinet,building the online monitoring system hardware platform.Secondly,the fault simulation model is built by using Simulink software for the high error rate of the power electronic device in the test drive platform.The sampling data of single period of different faults are collected,and the data is extracted by the method of wavelet packet decomposition and reconstruction,and the feature is used as the input of fault classification of extreme learning machine.However,due to the strong nonlinearity of power electronic circuits,the traditional learning algorithm can not get better classification results.The topic introduces the idea of kernel and uses the kernel extreme learning machine method to do further classification test.through adjusting the parameters can get better classification results.And the rationality of this method is confirmed from a theoretical point of view.Then,based on the functional requirements of on-line monitoring and fault diagnosis,the software function is designed by using LabVIEW graphical programming environment.The design includes data acquisition,analysis,display,storage and playback,fault diagnosis and so on.Finally,depending on data acquisition hardware system and upper computer program design,the topic implemented on-line monitoring of various signals of the original system in aerospace test site,and completed the fault diagnosis of the positioning of each part of 1#rectifier,2#rectifier,DC motor excitation module,synchronous generator excitation module.The results show that the design of the online power electronic equipment fault diagnosis system based on virtual instrument has high flexibility and operability,at the same time,it reduces troubleshooting time and has certain application value in engineering.