Study on inverter fault-tolerant operation of PMSM DTC

摘要

This paper presents an investigation of inverter fault-tolerant operation for a permanent magnet synchronous motor(PMSM)direct torque control(DTC)system under various inverter faults.The performance of a faulty standard 6-switch inverter driven PMSM DTC system is analyzed.To avoid the loss or even disaster caused by the inverter faults,a topology-modified inverter with fault-tolerant capability is introduced,which is reconfigured as a 3-phase 4-switch inverter.The modeling of the 4-switch inverter is then analyzed and a novel DTC strategy with a unique nonlinear perpendicular flux observer and feedback compensation scheme is proposed for obtaining a continuous,disturbance-free drive system.The simulation and experimental results demonstrate that the proposed inverter fault-tolerant PMSM DTC system is able to operate stably and continuously with acceptable static and pretty good dynamic performance.