基于九开关变换器的对称六相永磁同步电机逆变器开路故障诊断OA

[Objective]To improve the reliability of the symmetrical six-phase permanent magnet synchronous motor(PMSM)drive system,this paper constructs a dynamic model based on a nine-switch converter and proposes an innovative open-circuit fault diagnosis method for the inverter.[Methods]Considering the dead-time effect of pulse width modulation,the logical mapping between the motor winding terminal-to-ground voltage and the switch state was defined.The dynamic correspondence between the phase voltage and the switch signal was established,and a unified logical model of the hybrid system was derived.Based on voltage hybrid logic operations,the voltage differences between standard and fault states were compared,and open-circuit faults were accurately located.[Results]The simulation results demonstrated that when an open-circuit fault occurred in the symmetrical six-phase PMSM inverter,the faulty switch could be accurately located through dynamic logic transformation and voltage difference analysis.[Conclusion]The proposed diagnostic method can effectively identify faults in a single switch or simultaneous open-circuit faults in two switches of the same bridge arm,demonstrating high accuracy and universality.