Fault tolerant four-leg matrix converter drive topologies for aerospace applications

This paper proposes two types of fault tolerant matrix converter drive topologies, namely a four-leg single-stage matrix converter and a four-leg two-stage matrix converter, both used to drive a permanent magnet synchronous motor (PMSM) against open phase failure in aerospace applications. To improve the reliability of the drive system under open phase fault the motor neutral is connected to the fourth leg of each matrix converter without modifying the space vector modulation techniques. To maintain a satisfactory system performance the control strategy needs to be modified during fault occurrence so that the motor is able to operate continuously with minimum torque ripple. The simulation results of both proposed matrix converter drive topologies, under healthy and unhealthy conditions are presented to demonstrate the capability of the proposed fault tolerant drives. Moreover, the experimental results are provided to verify the effectiveness of the four-leg matrix converter drive´s ability to keep the motor running with only a small performance degradation under open phase fault.