一种基于保角映射的考虑端部效应的准三维轴向磁通电机磁场解析模型  

A quasi-3-D analytical model of magnetic field for axial-flux motor based on conformal mapping method considering end effect

作　　者：佟文明[1] 荆明 TONG Wen-ming;JING Ming(National Engineering Research Center for Rare-Earth Permanent Magnet Machines,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]沈阳工业大学国家稀土永磁电机工程技术研究中心,沈阳110870

出　　处：《电机与控制学报》2021年第8期47-55,共9页Electric Machines and Control

基　　金：国家自然科学基金(51677122);霍英东教育基金会青年教师基金(171049);辽宁省百千万人才工程项目。

摘　　要：轴向磁通永磁电机气隙磁场三维分布不均,且在电机内、外径处端部效应明显,应建立三维磁场模型来进行电机性能分析,而三维有限元计算十分耗时,因此需建立(准)三维气隙磁场解析模型。现有的考虑端部效应的AFPMMs气隙磁场解析模型,大多基于三维FEM辅助建模或等效磁路的方法,存在耗时过多或建模精确度不高的问题。针对以上不足,建立了基于保角映射的考虑端部效应的准三维AFPMMs磁场解析模型。将AFPMMs径向-轴向平面横截面等效为具有铁磁边界的多边形面域,永磁体等效为线电流,借助保角映射法,求取电机径向-轴向平面上的磁场分布,以得到端部修正系数,从而考虑端部效应对气隙磁场分布的影响。使用该解析模型,计算了一台AFPMM的气隙磁密与空载反电动势,与三维FEM、样机实验结果进行对比,以验证该模型的准确性。相比等效磁路法,在电机内、外径处,该解析模型气隙磁密计算精确度提高了10.61%;相比三维FEM,该解析模型计算用时仅为其耗时的0.078%。Axial flux permanent magnet motors(AFPMMs)have uneven three-dimensional air gap magnetic field distribution,and the end effect at the inner and outer diameters of the motor is obvious.The 3-D finite element method(FEM)has the disadvantage of being very time-consuming.Therefore,it is necessary to establish a(quasi)3-D air gap magnetic field analytical model.The existing analytical models of the air gap magnetic field of AFPMMs are mostly based on 3-D FEM-assisted modeling or the magnetic equivalent circuit(MEC),having the problem of time-consuming or low modeling accuracy.Aiming at the above deficiencies,a quasi-3-D AFPMMs magnetic field analytical model based on conformal mapping method considering the end effect was established.The radial-axial plane cross-section of AFPMMs is equivalent to a polygon domain with ferromagnetic boundary,and the permanent magnet is equivalent to line current.The conformal mapping method was adopted to obtain the magnetic field distribution on the radial-axial plane of AFPMMs to obtain the end effect correction coefficient,and the influence of the end effect was considered.Using this analytical model,the air-gap flux density and no-load back EMF of an AFPMM were calculated and compared with the 3-D FEM and prototype experimental results to verify the accuracy of the analytical model.Compared with the MEC model,the calculation accuracy of the air gap flux density of this analytical model is increased by 10.61% at the inner and outer diameters of the motor.Compared with the 3-D FEM,the process time of the analytical model is only 0.078% of 3-D FEM.

关 键 词：轴向磁通永磁电机 解析法 保角映射法 准三维解析模型 端部效应 许克变换 

分 类 号：TM351[电气工程—电机]