基于单阈值的开关磁阻电机无位置传感器技术

针对位置传感器对开关磁阻电机（Switch Reluctance Motor，SRM）应用范围的限制，研究了一种基于单阈值脉冲注入法的开关磁阻电机无位置传感器控制策略.以三相6/4结构电机为例，讨论在母线电压变化情况下向某一非导通相注入脉冲，通过均值采样方法计算脉冲电流峰值，与预设电流阈值比较实现位置估算.根据相邻阈值的时间间隔计算出电机转速，进一步获得其他相位置信息，并分析了估算位置与实际位置偏差的产生原因.该方法不但降低了脉冲注入带来的负转矩影响，还可实现角度控制，便于电机运行状态的优化.运用所述方法搭建了SRM无位置传感器调速系统的仿真模型，并通过试验证明了其正确性和可行性.
This paper presented a control strategy of indirect position estimation for switched reluctance motor (SRM) based on the single threshold of pulse injection in order to reduce the application scope of the limitation due to the position sensors. Considering the case of the bus voltage change, through injecting voltage pulse into one idle phase of 6/4 motor, the pulse peak current is detected by the mean sampling method proposed in this paper. The results are then used to predict the position by means of comparing the current preset threshold. After acquiring the time interval between adjacent threshold, it is convenient to calculate the speed and to confirm other position at every time. The deviation between estimated position and actual position was also analyzed. The proposed method not only reduces the negative torque influence brought by injection pulse but also flexibly implements the angle control that optimizes the motor running state. The SRM sensorless speed control system is built in Simulink, and the DSP experiment results verify the present method.