Open Circuit Fault Diagnosis of Five Phase Permanent Magnet Synchronous Motor Drive System Based on Hybrid Logic Dynamic Model

In response to the problem of difficulty in locating faults in the inverter of a five-phase permanent magnet synchro-nous motor (PMSM) drive system after an open circuit fault, a fault diagnostic strategy based on mixed system state residual is proposed. By establishing a mixed logical dynamic (MLD) model that can represent the five-phase current, the output current of the dynamic model after a switch fault is derived, and the fault output current is compared with the normal current output of the drive system. The residual current is obtained for fault diag-nosis and localization, in order to enhance the stability of the diagnosis strategy, a threshold current determination method is researched. Three switching faults in the motor drive system are analyzed using simulation to verify the effectiveness of the diag-nostic strategy.