Surface vs. Embedded Magnets in Permanent Magnet Outer Rotor Synchronous Motors

Abstract

A comprehensive comparison of two topologies of outer rotor Permanent Magnet Synchronous Motors (PMSMs) is given. Specifically, it examines outer rotor motors with rotor surface magnets (S-PMSM) and those with embedded V-positioned magnets (V-PMSM) under geometric constraints dictated by the system's requirements for high specific torque. The investigation involves initial design considerations and Finite Element Method (FEM) optimization for maximizing the specific torque while minimizing torque ripple. Both motor designs aim to achieve a high torque density and specific torque alongside a substantial field-weakening capability for efficient operation across a broad speed range. The analysis covers aspects of design methodology, optimization processes, and performance evaluation, including torque production and efficiency.