Inverter Fault Tolerance in BLDC Drives for Electromechanical Aerospace Actuators

This paper presents fault tolerance strategies for failures occurring in power devices of inverters of a permanent magnet brushless dc motor drive, typically used in aerospace actuators. It proposes a scheme for detection and reconfiguration for inverter switch faults. Experimental verification of switch fault detection logic is also presented. The reconfiguration topology proposed here utilizes an additional inverter leg connected to the neutral of the motor. The result shows that the proposed scheme can deliver 50-100 percent of rated torque depending on the phase of the failed device and the angle command on this actuator. The scheme, therefore, is used for mission critical aerospace actuator with some less of actuator bandwidth.