A fault tolerant machine drive based on permanent magnet assisted synchronous reluctance machine

A fault tolerant machine drive based on permanent magnet (PM) assisted synchronous reluctance machine is proposed and investigated for safety critical applications. In order to achieve enhanced fault tolerant capability, the risk of the permanent magnet field that cannot be turned off under fault conditions is minimized without compromising the torque density and efficiency. This is achieved by employing a synchronous reluctance rotor topology with embedded permanent magnets. Three independent 3-phase windings are adopted and a segregated winding configuration is devised to ensure non-overlapping in the three 3-phase winding sets. Each 3-phase winding set is driven by a standard 3-phase inverter, which facilitates fast integration and cost reduction. The performance under various fault conditions has been evaluated by FE simulations. The results show that the proposed machine drive exhibits high performance as well as excellent fault tolerant capability under various faults, including open circuit, terminal short circuit, and inter-turn short circuit, etc.