开关磁阻电机铁损的双频法有限元计算研究

文中对1台三相12/8结构开关磁阻电机进行了四分之一域的二维(2D)电磁场有限元分析,得到了大小和方向都随时间变化的铁心磁密矢量的X和Y分量,从而更细致地描述了电机铁心各单元磁密随时间(转子位置角度)的变化周期和规律。在无需知道电机铁心材料的损耗系数(即涡流修正因子和局部磁滞回线因子)的情况下,以磁密的计算信息和铁心材料单位体积的铁损密度数据为基础,通过双频法分离出铁损中的涡流损耗和磁滞损耗,再用频率分解法和最大磁密法分别计算这2种损耗,并对占电机铁心铁损较大比例的涡流损耗进行了离散傅里叶分解,比较各次谐波分量对铁损的影响。由间接法计算出铁损的实验值,近似地分离了铁损和杂散损耗,实验验证了该铁损计算方法的准确性。

A Study on Iron Loss Finite Element Analysis of Switched Reluctance Motor Based on a Double-frequency Method

Switched reluctance motor(SRM)performance prediction requires the modeling of iron losses.In this paper the magnetic fields and iron losses of a three-phase 12/8 SRM are analyzed and calculated.The magnetic flux density is described by X component and Y component in Cartesian coordinate system.Although the iron loss constants are unknown,based on the magnetic flux density waveforms and the iron loss data per volume of the motor material,the hysteresis losses and eddy-current losses in different parts of the motor are calculated separately using a double-frequency method.The eddy-current losses are then analyzed by performing a discrete Fourier transform frequency analysis,so the effects of different harmonic components on iron losses can be compared.The calculation of iron losses is verified and validated through indirect experiment in which the iron loss and stray-load loss are separated approximatively.