Fault Analysis and Remedial Strategies on a Fault-Tolerant Motor Drive with Redundancy

Fault-tolerant motor drives are required in a range of safety-critical applications. Using a special motor design and an appropriate inverter topology, brushless permanent magnet AC motor drives can have an effective fault-tolerant capability. Although a single motor fault-tolerant drive system may be sufficient in many critical applications, a higher degree of fault tolerance requires redundancy in the motor system as considered in this paper. This is achieved by using a dual motor module on a common shaft. The simulation model of the entire drive system and the analysis of the various faults are presented in this paper. The effects of fault(s) on the phase current and output torque are provided. Three remedial operating modes are proposed and their features are compared. In addition, an experimental setup was introduced, which is based on dual electrically and magnetically isolated brushless AC motor modules, h-bridge inverters for individual phases and dsPICDEM MCU motor controller.