Research on Fault Tolerant Inverter based Permanent Magnet Synchronous Motor Direct Torque Control Drives

This paper investigates the integrated performance of a permanent magnet synchronous motor (PMSM) direct torque control (DTC) drive system based on inverter faults. A switch-redundant inverter with fault tolerant capability is introduced to substitute the standard 6-switch 3-phase inverter in the drive system; two 4-switch inverters are reconfigured when open-phase or short-switch faults occur. Modelling of the 4-switch inverters are analyzed, a modified DTC strategy based on these two post-fault 4-switch inverters is proposed for the disturbance-free operation of the PMSM drive. The proposed PMSM DTC system are simulated under both healthy and faulty conditions, integrated simulation results verify that the modified PMSM DTC drive systems under both two 4-switch inverters are able to operate stably and continuously with acceptable performance