Optimization and Comparative Analysis of Magnet Shapes in 5-MW PM Vernier Motors for Marine Propulsion

Abstract

Permanent magnet (PM) motors are increasingly used in high-power applications such as marine propulsion systems, where their exceptional torque density and efficiency are paramount. The configuration of PMs significantly affects the motor's performance and cost, making it a key design consideration. This study focuses on the design, optimization, and comprehensive comparative analysis of PM Vernier motors (PMVMs), specifically designed for a 5-MW marine propulsion system-a power level previously unexplored for Vernier motors. It examines four distinct magnet shapes: surface-mounted, spoke array, V-shape, and U-shape. Utilizing a Non-Dominated Sorting Genetic Algorithm II (NSGA-II) optimization algorithm, the study aims to minimize mass and cost. The optimally chosen models are then extensively compared, focusing on their cost and electromagnetic attributes, including airgap flux density, back-EMF, torque, power factor, self-inductance, loss, efficiency, and force performance. The findings underscore the significant role of magnet shape in enhancing the performance and total mass of high-power PMVMs, providing critical insights for the advancement of cost-effective and high-performing electric propulsion systems.