On inverter fault-tolerant operation vector control of a PMSM drive

The paper describes an investigation of inverter fault-tolerant vector control for permanent-magnet synchronous motor (PMSM) driven by a fault-tolerant inverter. The inverter is a topology-modified inverter with fault-tolerant capability, which can be configured as the standard 3-phase 6-switch inverter under the inverter health condition and reconfigured as 3-phase 4-switch inverter under the inverter fault condition respectively. By analyzing operating principle of a fault-tolerant inverter and the mathematic model of PMSM, current and voltage character of three fault-tolerant method (phase A fault-tolerant, phase B fault-tolerant and phase C fault-tolerant) in the fault-tolerant converter are investigated and there is a conclusion that three phase currents of three phase stator windings of PMSM can be controlled effectively by controlling two phase currents of them randomly. Then, a novel vector control scheme is proposed to drive PMSM based on the fault-tolerant inverter. The strategy is feasible and simple. Simulation results show the validity of the proposed method.