两相混合式步进电机减小齿槽转矩的方法

为提高混合式步进电机的位置和速度控制精度， 需要减小电机的齿槽转 矩。本文推导了两相混合式步进电机定转子等齿距和不等齿距时齿槽转矩的解析表达 式，提出了通过微调定子齿距为最优角度的错齿方法，能够消除气隙磁导4 次谐波产生 的转矩分量，从而减小电机的齿槽转矩。设计了3 台不同定子齿距的样机，对齿槽转矩 和保持转矩分别进行了二维有限元计算和试验测试，结果表明，通过定子错齿方法，能 够明显减小齿槽转矩，使矩角特性的波形接近正弦波。

Method for Minimizing Cogging Torque in Two-phase Hybrid Stepper Motor

To improve the accuracy of the position and the speed control for hybrid stepper motor, the inherent cogging torque needs to be reduced. In this paper, the analytical expressions of the cogging torque for two-phase hybrid stepper motor, making the stator tooth pitch equal and unequal to the rotor tooth pitch, are both derived. The method by fine adjusting the stator tooth pitch to the optimal angle can eliminate the torque developed by the 4th harmonic component in the airgap permeance, and thereby, the cogging torque is minimized. Three prototype stepper motors with different stator tooth pitch are designed. The torque values are obtained and compared by two-dimensional finite element method and by the test, respectively. The analysis results show that the cogging torque can be significantly reduced by the stator teeth misalignment, the torque-rotor angle characteristic is close to the sinusoidal waveform.