无位置传感器无刷直流电机启动方法研究

Research on Starting Method of BLDC Motor

针对无位置传感器无刷直流电机普遍采用的反电动势过零检测转子位置的方法存在启动困难的问题,提出了一种改进的三段式启动方法,具体包括预定位、外同步加速过程和切换到自同步3个阶段。在预定位阶段采用施加短时检测脉冲来确定转子初始位置。在外同步加速阶段提出了一种比较精确的在不同负载情况下换相时刻的计算方法,并分析了加速过程中换相的准确性。该方法能够提高电机启动过程中定位的准确性和启动的成功率,降低失步和启动失败的可能性。

The back-EMF-detection-zero-crossing detection method adopted by most sensorless BLDCM control causes the starting problem.Aiming at this,an improved three-step starting method was proposed,which includes three steps of rotor initial position estimation,separately-controlled synchronous mode and self-controlled mode.Short time measure pulse was adopted for rotor initial position deciding during rotor locating stage.A more accurate commutation time calculation method was put forward and the deep analysis of the commutation accuracy was done during the acceleration.Through this method,the BLDCM can start from standstill smoothly.Loss of synchronization or starting failure can be avoided in a large part.