Design and Research of Axial Flux Permanent Magnet Motor

doi:10.11985/2019.04.005

Abstract

Abstract:

Wheel-edge motor improves the operation performance of electric vehicles, but brings high technical requirements of the motor．An axial flux permanent magnet wheel-edge motor with double stator and single rotor structure is proposed. Focusing on the purpose of reducing the THD of back electromotive force, reducing torque pulsation and rotor eddy current loss, the stator slot type, pole-slot combination, skewed permanent magnet and segments of permanent magnet, number of winding layers and number of conductors per slot of axial flux permanent magnet are analyzed. In order to realize high overload capacity, the spiral channel heat dissipation design is presented. For the purpose of reducing the weight of the motor, the weight reduction design is carried out on the front and rear end cover, shell and rotating shaft of the motor. Meanwhile the strength analysis and modal analysis are finished by FEA tools. Finally, a prototype of the axial magnetic flux permanent magnet wheel-edge motor is produced, and an experimental platform is built to test the efficiency characteristics, magnetic field weakening properties and temperature rise of the motor. The experimental results verify the rationality of the design scheme.

Key words: Electric vehicles, axial flux, torque pulsation, eddy current loss, field weakening

CLC Number:

U469

Qi HUANG,Ling LUO,Liangkuan JIN,Yang TANG. Design and Research of Axial Flux Permanent Magnet Motor[J]. Journal of Electrical Engineering, 2019, 14(4): 32-41.

Figures/Tables 24

References 16

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轮边电动机类型	优点	缺点
异步电动机	结构简单,经久耐用,环境适应能力强,维护简单。	效率较低,体积偏大,转子易发热,功率因数低,控制成本高,调速性能差。
径向开关磁阻电动机	结构简单,转子耐高温,可靠性高,维修简单,低速性能好。	转矩波动较大,噪音较大,控制系统复杂,效率偏低,体积较大。
径向永磁无刷直流电动机	效率高,功率密度较大,能够适应高速运行,维护简单。	受制于永磁体工艺、特性的限制,功率范围较小。抗恶劣环境能力不强,转矩波动较大。
轴向磁通永磁同步电动机	轴向尺寸短,结构紧凑,质量轻,适合轮边驱动,转矩密度高,高效。	弱磁扩速能力较差,结构较复杂。

极对数p	定子槽数Z
1	6、12、18、24、30、36、42、48、54、60、66、72
2	12、24、32、36、48、60、72
3	18、36、54、72
4	24、48、72

参数	数值	参数	数值
槽口宽/mm	2.8	并联支路数a	2
槽深/mm	28	永磁体剩磁Br/T	1.23
槽宽/mm	8.3	永磁体矫顽力Hc/(kA/m)	890
槽肩角/(°)	20	槽满率	0.72

部件	热导率/[W·(m·K)^–1]			比热容/ [J·(kg·K)^–1]
部件	径向	周向	轴向	比热容/ [J·(kg·K)^–1]
铁心	4.3	35	35	502.4
空气	0.029	0.029	0.002 9	1 005
绕组	223	0.63	0.63	654
绝缘材料	0.21	0.21	0.21	1 700
永磁体	9	9	9	440
机壳	210	210	210	871
槽楔	0.2	0.2	0.2	1 500

名称	弹性模量 E/Pa	密度ρ/ (kg/m³)	泊松比 μ
定子铁心硅钢片	206×10⁹	7 850	0.30
绕组铜线	120×10⁹×λ	8 890×λ	0.35
槽绝缘	3×10⁹	800	0.38
铝制机座	75×10⁹	2 700	0.33
转轴	207×10⁹	7 800	0.25
转子支架	206×10⁹	7 900	0.30