Demagnetization Risk Assessment in a Dual Stator Permanent Magnet Vernier Machines

As the topologies of permanent magnet vernier machines (PMVM) is getting more complex such as dual rotor and its variants. The thermal, mechanical, and especially demagnetization concern increasing. In this paper, the demagnetization risk evaluation of three similar topologies of dual stator radial type PMVM is presented. Three recently published topologies: dual winding with rotor-yoke, dual winding without rotor-yoke, and single winding without yoke are selected. This design highly improved the torque density and reduced the overall volume. However, the permanent magnets (PMs) in these topologies are at huge risk of irreversible demagnetization. Furthermore, the overall performance of PM-type machines is incomprehensible without a detailed demagnetization analysis. Therefore, a comprehensive mechanical, thermal, and demagnetization analysis considering various operating points and temperatures is conducted to evaluate the risk of demagnetization in these topologies. Finally, some modification are made to optimize of these designs. All analyses are carried out using finite element analysis and co-simulation in ANSYS maxwell and mechanical.