轴向磁通非晶合金永磁电机空载铁耗的解析计算方法

Analytical Method of No-Load Iron Losses of Axial Flux Amorphous Alloy Permanent Magnet Motor

非晶合金材料具有出色的低损耗特性,利用非晶合金替代硅钢片制作轴向磁通永磁电机铁心可有效降低电机铁心损耗,但替代后的非晶合金电机的损耗结构也将发生改变。在电机初始设计阶段,快速准确计算出电机的空载铁耗是轴向磁通非晶合金电机设计及优化的关键。该文针对3D时步有限元计算耗时长的问题,改进现有多环等效模型计算方法,推导了气隙磁密、定子铁心损耗和永磁体涡流损耗的解析解,构建了空载铁耗的解析计算模型。利用3D有限元对解析模型计算值进行了验证,结果显示解析计算模型计算误差仅为9.42%。利用该解析模型分析槽口和气隙长度对空载铁耗的影响,结果显示采用减小槽口宽度降低空载铁耗的效果更为明显。

The core loss of axial flux permanent magnet motor will decrease a lot when the silicon steel core is replaced by the amorphous alloy core in consideration of the outstanding low power loss characteristics of amorphous alloy material, but the loss structure of amorphous alloy motor will be different from the silicon steel motor. The key for design and optimization an amorphous alloy axial flux permanent magnet motor is the fast and accurate calculation of no load iron losses during the original designing stage. In this paper, because of the large time consuming of three dimensional time step finite element analysis method, the present multilayer coupled model was further improved, the analytical methods of air gap flux density, stator core loss and permanent magnet eddy current loss were derived, and an analytical model of no load iron losses was then established. The analytical calculation results were compared with the results obtained by three dimensional FEA method, and it is shown that, the average calculation error of no load iron losses is 9.42%. The influences of slot width and air gap length to the no load losses were analyzed using the proposed analytical method, and the results show that, it is more effective to reduce the iron losses by narrowing the slot width.