两种转子结构形式无刷直流电动机电磁场及热场分析

Exploring Coupled Electromagnetic Field and Thermal Field for Two Types of Rotor Configuration of Brushless DC(BLDC) Motor

文章针对表贴式径向励磁和内嵌式切向励磁两种转子结构,分析了无刷直流电动机的电磁场及热场的计算过程;利用电磁场-热场耦合的有限元方法,研究了两种电机结构的电磁场和热场分布,采用这种方法不仅可以精确计算电机内部电磁场的分布,而且可以得到电机内部电磁场与热场之间的能量交互过程,研究电机的发热问题。通过样机实验和仿真结果对比,发现表贴式结构紧圈发热比较严重,嵌入式结构在磁钢端部存在漏磁,导致环流引起电流波形发生畸变,并给出了相应的解决方案。

Aim.The introduction of the full paper reviews the achievements of Refs.1 through 5.We now propose using the mathematically more accurate finite element analysis of coupled electromagnetic field and thermal field to explore the locations of trouble for two types of rotor configuration of a BLDC motor： surface-mounted radial exciting and interior tangential exciting.Sections 1,2 and 3 explain our method of exploration;they are respectively entitled electromagnetic field,thermal field and the finite element analysis of coupled electromagnetic field and thermal field.In section 3,Figs.1 through 4 give the calculated results for the two types of rotor configuration（unfortunately NWPU Journal prints them in black and white instead of in color as they should be）.Section 4 presents in Figs.5,8 and 9 the experimental results for the two types of rotor configuration.Section 5 gives concluding remarks;its core consists of：（1） the temperature rise in the retaining sleeve of surface-mounted configuration is severest and we offer suggestions on how to alleviate it;（2） the flux leakage is highest in the magnet terminal of interior configuration,causing circulating flow in the current,and we offer suggestions on how to alleviate it.