A Fault-Tolerant Machine Drive Based on Permanent Magnet-Assisted Synchronous Reluctance Machine

Abstract

A fault-tolerant machine drive based on permanent magnet-assisted synchronous reluctance machine is proposed and investigated for aerospace applications where reliability and safety are crucial. In order to achieve enhanced fault-tolerant capability, the risk of permanent magnet field that cannot be turned off under fault conditions is minimized without compromise in torque density and efficiency. This is achieved by employing a synchronous reluctance rotor topology with embedded permanent magnets. Three independent segregated three-phase windings are configured to ensure isolation and nonoverlapping between the three 3-phase winding sets. Each three-phase winding set is driven by a standard three-phase inverter to facilitate fast integration and cost reduction. The machine behavior under various fault conditions has been evaluated by finite element simulations. A 40 kW prototype was designed, constructed, and tested. The test results demonstrate the performance and excellent fault-tolerant capability of the proposed drive system under various faults, including open-circuit and short-circuit conditions.