开关磁阻电机电磁力和转矩的解析表征

Analytic Method of Magnetic Force and Torque of Switched Reluctance Motor

由于磁饱和非线性,开关磁阻电机电磁合力和转矩的计算缺乏系统有效的方法,造成电机振动和噪声评价困难。本文综合等效电路、拟合函数和麦克斯韦应力法等方法,推导电磁合力和转矩的完整解析表达。先通过等效磁路法计算出电机在4个特殊角度位置的磁链,然后利用函数拟合法获得电机的磁链转矩和切向力;再基于麦克斯韦应力法,推导单定子绕组受激时转子所受电磁径向力的表达式;最后在六相绕组轮替方波电流激励下,计算转子转动受到的电磁合力和合转矩。经电磁有限元仿真验证,证明该解析表征更加便捷高效。它基于初步设计的结构尺寸和硅钢参数,体现了电机参数之间的联系。结果为后续开展转子弯扭耦合振动行为和噪声控制研究奠定了基础。

Due to nonlinearity of magnetic saturation, electromagnetic force and torque of the switched reluc-tance motor are not effective in calculating the vibration and noise of the motor. In this paper, equivalent cir-cuit, fitting function and MaxweU stress method were used to derive the complete analytical expression of e-lectromagnetic force and torque. Firstly, Magnetic chain of the motor in four special angles was calculated by means of the equivalent magnetic circuit method, and then the magnetic torque and tangential force of the motor were obtained by using fitting function. Based on the MaxweU stress method, the expression of electro-magnetic radial force of the rotor was derived. Finally, with square wave current excitation of six-phase winding, electromagnetic force and torque of rotor were calculated. It is proved by electromagnetic finite ele-ment simulation that the analytical method is convenient and efficient. It is based on initial structure size and parameters of the silicon steel, which shows the relation of motor parameters. The results provide a basis for the follow-up coupling vibration behavior of the rotor and noise control.