Multiobjective Optimization Design of Unequal Halbach Array Permanent Magnet Vernier Motor Based on Optimization Algorithm

This article proposes a consequent-pole unequal Halbach vernier wheel motor (CPUHVWM), which effectively reduces the self-flux leakage between permanent magnets, and an optimization method is proposed to improve the motor optimization efficiency and shorten the optimization time. The key variables are selected by the sensitivity analysis, and a polynomial function suitable for the optimization algorithm is constructed based on the response surface method. Based on the particle swarm optimization algorithm, the weights of different particle search areas are assigned to improve the overall optimization efficiency of the algorithm. Furthermore, to verify the superiority of the performance of the proposed structure and the applicability of the algorithm, the other two similar motor structures are compared, and the algorithm is adopted for the optimization. The optimized electromagnetic characteristics are compared by the finite element method. Finally, the prototype with the optimal parameters is built, and the effectiveness and advantages of the optimization algorithm are verified by experiments.

I. Introduction

Wheel motor is one of the development directions in the field of transportation drive in the future, because of its simple structure and high transmission efficiency [1], [2]. Due to the demand for low speed and high torque, a wheel motor is either a high-speed motor connecting with reducers or a low-speed direct-drive motor. Although the overall volume of the former one can be reduced, the transmission loss and mechanical noise of the whole system are increased due to the reducer [3]. On the other hand, although the reducer is omitted for the latter one, large volume and heavy mass are caused by the low-speed direct drive characteristics [4]. Therefore, it is necessary to combine the advantages of the above structure to develop a small size and low-speed direct drive wheel motor.