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Structural Optimization of External Rotor Permanent Magnet Motor Based on Halbach Magnetization

This paper takes an external rotor permanent magnet synchronous motor (ERPMM) as the research object, and analyzes the magnetic circuit structure and working principle of the motor. According to the design parameters and design structure of the motor, the motor is analyzed by combining the finite element method and the analytical method. In this paper, increasing the output torque of the motor and reducing the cogging torque are the optimization goals, and the design uses the Halbach magnetization structure as the main method to optimize the design of the motor to form an A-type Halbach magnetized external rotor permanent magnet motor (HERPMMA). On the basis of improving the magnetizing structure, the structure of the permanent magnet motor is parametrically analyzed and optimally designed to form a B-type Halbach magnetized external rotor permanent magnet motor (HERPMMB). In this way, the torque performance of the motor can be further improved on the basis of giving full play to the advantages of Halbach's magnetization structure. The operating performance of the three motors is compared and analyzed, and the optimization results are evaluated by integrating multiple optimization objectives. The results show that the output torque and permanent magnet utilization of HERPMMB increased by 42.88%, and the cogging torque of the motor decreased by 78.63% compared with ERPMM without changing the amount of permanent magnets.

Permanent Magnet Motor, Halbach Magnetization, Cogging Torque, Torque Output, Structural Optimization

Zhiyuan Ren, Tianyun Liu. (2023). Structural Optimization of External Rotor Permanent Magnet Motor Based on Halbach Magnetization. American Journal of Electrical Power and Energy Systems, 12(3), 51-58.

Copyright © 2023 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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