无刷直流电动机无传感器换相误差自校正方法

Self-Compensation Method for the Commutation Error of Sensorless Control of Brushless DC Motor

针对无刷直流电动机无位置传感器换相技术存在残留换相误差问题,研究了一种换相误差自校正的控制方法。将电机一相绕组端电压与中性点电压作差处理的信号输入至采样电路,在该相绕组导通前后对称位置,分别对该信号采样,并以前后两次采样电压相等为目标,建立换相误差PI控制回路。经控制回路对换相误差的校正,导通前后两次采样的电压最终收敛到相同的电平;与此同时,电机换相点收敛到正确的时刻。实验表明,该方法仅利用电机一相绕组以及中性点,便能有效对换相误差实现闭环校正,实时补偿外界因素对换相间隔时间的干扰。

To reduce the commut ation error of the sens or less control of brushless DC motor , a self - compensation met h-od was proposed. At the point of one phase turned on and off, special voltage of was sampled. After the two voltage sub-tracted ,acontrol loop was introduced to make the voltage difference approach zero. Time phase change point was led to the accurate position at the same. Two point of the back-EMF was sampled during an electrical cycle to compensating commu-tation error. The experiment verified that the method was simple and reliable.