Performance Improvement of Multi-Rotor Axial Flux Vernier Permanent Magnet Machine by Permanent Magnet Shaping

Abstract

Permanent magnet vernier machines (PMVMs) are becoming progressively attentive because of their high efficiency and high torque density and can thus be utilized for direct-drive applications such as wind power and electric vehicles etc. This paper presents performance improvement of multi-rotor axial flux vernier permanent magnet (MR-AFVPM) machine with a proposed two-stage parallelogram-shaped PM. The proposed shaped PM reduces the cogging torque and torque ripples due to its skew effect. Furthermore, it also presents a comparative analysis of the conventional and proposed shape PM. Then 3D finite element analysis (FEA) is used for comparative analysis. Genetic algorithm (GA) associated with kriging method based on LHS is introduced and is used to optimize the proposed shaped PM for further performance improvement in terms of cogging torque, back EMFs, torque ripples, VTHD, output torque, flux density distributions, power factor and output power of the analyzed machines which are validated by 3D-FEA.

Keywords

• Axial flux
• Vernier machine
• torque density
• cogging torque
• genetic algorithm
• 3D-FEA