双调制式轴向永磁齿轮电动机气隙磁场与转矩计算

Calculation of Air Gap Magnetic Field and Torque of Dual-modulation Axial Magnet Gear Motors

针对轴向永磁齿轮电动机(Axial Magnetic Gear Motor,AMGM)整体尺寸偏大导致的转矩密度偏低(≤70 kN·m/m^(3))等缺陷,提出了一种双调制式轴向永磁齿轮电动机(Dual-modulation Axial Magnetic Gear Motor,DAMGM)。采用高速侧及低速侧两个调磁环对DAMGM低速转子进行调制,且两个调磁环中的非导磁部分均为永磁体,有效提高了低速转子的输出转矩;另外,与现有AMGM相比,将驱动电动机置于DAMGM高速永磁转子内部,减小了整体轴向尺寸,大幅提高了低速转子的转矩密度(150 kN·m/m^(3))。针对现有3D有限元计算时间长、计算机资源浪费严重等问题,给出一种基于圆柱坐标系的DAMGM三维分析方法。根据调磁环的3种边界条件,建立了调制后DAMGM气隙磁场及电磁转矩的数理模型,不仅计算结果准确(与3D有限元相比,平均计算误差≤5%),而且计算时间短(仅为3D有限元的1/10),便于DAMGM不同参数结构的分析、比较与优化。

A dual-modulation axial magnet gear motor(DAMGM)was proposed to address the shortcomings of the axial magnet gear motor(AMGM),which has a large overall size and low torque density(≤70 kN·m/m3).Two magnetizing rings on the high-speed and low-speed sides were used to modulate the low-speed rotor in the DAMGM,and the non-magnetic parts in both magnetic magnetizing rings were permanent magnets,effectively improving the output torque of the low-speed rotor.In addition,compared to the existing AMGM,the drive motor was placed inside the high-speed permanent magnet rotor of the DAMGM,reducing the overall axial size and significantly improving the torque density of the low-speed rotor(150 kN·m/m3).Aiming at the problems of long calculation time and serious waste of computer resources in the existing 3D finite element method,a 3D analysis method of DAMGM based on the cylindrical coordinate system was presented.According to three boundary conditions of the magnetizing ring,the mathematical and physical models of the modulated DAMGM air gap magnetic field and electromagnetic torque were established.The calculation results are not only accurate(compared with the 3D finite element method,the average calculation error is less than or equal to 5%),but also the calculation time is short(only 1/10 of the 3D finite element method),facilitating the analysis,comparison,and optimization of different parameter structures in the DAMGM.