Modeling and analyzing of magnetic field in unequal segmented Halbach array permanent magnet machine

Article type: Research Article

Authors: Guo, Liyan^a; | Wang, Huimin^a; | Gu, Xin^a | Shi, Tingna^b | Xia, Changliang^{a; b}

Affiliations: [a] School of Electrical Engineering and Automation, Tiangong University, Tianjin, China | [b] College of Electrical Engineering, Zhejiang University, Hangzhou, China

Correspondence: [*] Corresponding authors: Liyan Guo, School of Electrical Engineering and Automation, Tiangong University, No. 399 Binshui Xi Road, Xiqing District, Tianjin, 300387, China. E-mail: guoliyan@tju.edu.cn. Huimin Wang, School of Electrical Engineering and Automation, Tiangong University, No. 399 Binshui Xi Road, Xiqing District, Tianjin, 300387, China. Tel.: +86 13502076811; E-mail: wanghuimin@tju.edu.cn

Abstract: Permanent magnet machine adopting Halbach array has more sinusoidal air-gap flux density distribution and higher air-gap flux density magnitude. Compared with the equal segmented Halbach array, the fundamental magnitude of air gap flux density can be higher and distortion rate can be lower by reasonably designing each segment width in unequal segmented Halbach array. Thus, in this paper, the permanent magnet machine adopting unequal segmented Halbach array is researched. Firstly, an analytical model is established for PM machine adopting Halbach array to improve the calculation efficiency. This analytical model can be applied to the Halbach array having arbitrary pole pair number, arbitrary number of segments per pole, arbitrary segment width and arbitrary gap width between segments. Further, the calculation results for air gap flux density between analytical model and finite element method are compared to verify the analytical model. In addition, the method to determine each segment width in the unequal segmented Halbach array is proposed firstly in this paper. On this basis, effects of the gap width between segments and each segment width under one pole on air gap flux density are researched. The research conclusions will provide guidance for the design and fabrication of unequal segmented Halbach array.

Keywords: Analytical model, gap width between segments, unequal segmented Halbach array, segment widths under one pole

DOI: 10.3233/JAE-200009

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 2, pp. 333-353, 2021