Research On Fault Diagnosis Method For Matrix Converter Based Pmsm Drive System

Matrix converter has the characteristics of sinusoidal input and output current,controllable input power factor,wide range of input and output frequency,bi-directional energy flow,no intermediate energy storage link and high power density.Therefore,it has a broad application prospect in the field of motor drive which requires low harmonic distortion rate,high efficiency,high power density and high reliability.However,the matrix converter usually has more switching devices,and the motor drive system depends on the reliable work of sensors.The failure of switching devices or sensors poses a serious threat to the safe operation of the system.Thus,fast and reliable online fault diagnosis technology is particularly important.In this paper,the matrix converter based PMSM drive system is taken as the research object,focusing on open-switch faults,sensor faults and fault identification between them,and the following progress is made:(1)In this paper,an open-switch fault diagnosis method based on lineto-line voltage residuals is adopted in the matrix converter based PMSM drive system.Based on the full-order observer and open-loop observer,a diagnosis method based on sensor residual is proposed in this paper.(2)Due to the coupling of diagnosis algorithms among position sensor fault,current sensor fault and open-switch fault,further feature analysis is needed to extract decoupling features.For the coupling problem between diagnosis methods,a decoupling method based on the characteristics of residual value is proposed,and the specific diagnosis process is given.In addition,this paper provides a threshold selection method for reference,which can ensure the robustness of the system while ensuring the sensitivity of the system,and reduce the misdiagnosis rate.(3)Finally,a simulation platform based on RT-Lab is built to further verify the Correctness and effectiveness of the algorithm.