Analytical Modeling and Design Optimization of a Vernier Permanent Magnet Motor


In this paper, we present the analysis and design optimization of a Vernier permanent magnet (VPM) motor for direct-drive applications. A subdomain-based analytical model is developed for fast calculation of the electromagnetic performances, including air-gap flux, torque ripple, and power factor. Built on the analytical model, we investigate the trade-off between torque generation and power factor of the VPM motor, and conduct multi-objective optimization for key design parameter of the VPM motor. Flux density in different regions of the stator core is calculated from the analytical model, on which a constraint is set in the objective functions to consider the saturation effect. The optimized VPM achieves 1.9x torque output compared with a commercially-available surface-mount permanent magnet direct-drive motor with the exact inner and outer dimensions at the same speed.