Analysis and Design of Fault-Tolerant Dual Three-Phase Permanent Magnet Synchronous Machines for eVTOL Applications

The electric aircraft industry has received an increasing impetus over past decades, driven by the growing attention on environmental sustainability. This paper aims to propose a dual 3-phase fault-tolerant interior permanent magnet synchronous machine (FT-IPMSM) for electric vertical takeoff and landing (eVTOL) applications. Firstly, trade studies were performed on four permanent magnet (PM) configurations with considerations of high-torque-density and high reliability. Then, the multi-physics evaluation is undertaken on a 48-slot/8-pole FT-IPMSM with 2-layer V-shaped PM, during which the thermal viability and mechanical challenges are addressed from design aspects. The results demonstrate the mechanical performance of the machine can be improved by carefully optimizing the rotor structure. This paper also attempts to evaluate the fault-tolerance of the prototype with two different dual 3-phase winding configurations. It verifies that the proposed segregated dual 3-phase winding has comparable performance to the conventional design under both healthy and open-circuit (OC) fault, while the segregated winding has superior short-circuit (SC) fault currents and output torque under the SC condition.