无位置传感器无刷直流电机启动的新方法研究

Further Study for the Sensorless Brushless DC motor Start Method

针对无位置传感器无刷直流电机的启动问题,提出了对三段式闭环启动中的预定位、外加速过程的改进方法。在转子定位阶段采用基于空间电压矢量调制的短时脉冲来获得转子初始位置,精度可达15°。加速阶段采用施加空间电压矢量,通过检测母线电流变化率确定换相时刻,当速度达到额定转速的80%后,通过反电动势法进行换相。通过仿真分析可知,该方法能够有效的实现电机启动,并提高了启动的可靠性。

Aiming at the starting problem of sensorless permanent magnet brushless DC motor（BLDCM）,an im-proved start-up strategy in the initial rotor-position and the acceleration process which is based on closed-loop 3-step start-up strategy is proposed. In the rotor positioning stage,short space vector modulation is used to obtain initial rotor position,and the accuracy is up to 15°. In the rotor acceleration stage,short space vector is applied to determine the stator phase commutation by detecting the bus current rate of change. After the rate reaches 80%of rated speed,the method of back EMF is turned to use for commutation. The simulation analysis shows that this method can effectively implement motor starting,and the reliability of the motor start has improved.