基于反电势直接检测法的无刷直流电动机控制系统

为实现无刷直流电动机(BLDCM)无位置传感器控制,设计了一种通过直接检测空闲绕组反电动势来确定转子位置的BLDCM控制方案。重点介绍了反电势检测原理以及常用检测方法存在的不足,详细阐述了一种采用ADC在PWM ON期间直接检测反电势,并通过软件补偿提高过零检测精度的方法;详细讨论了BLDCM闭环换向运行和起动策略的工作过程。实验结果表明,该系统换向准确,高速运行稳定可靠,具有很好的工程实用价值。

BLDCM Control System Based on Direct-Back-EMF Detection

To realize the sensorless control of brushless DC motor(BLDCM),a BLDCM control solution was designed to detect rotor position by directly detecting the back electronmotive force(EMF) of idle winding.The detecting principle of back EMF and deficiency of routine techniques were highlighted,and a method was elaborated which directly detect the back EMF by ADC during PWM OM period and improve the zero-crossing testing accuracy by software compensation.The BLDCM loop-closed switch operation and starting-up strategy were discussed.The experimental results indicate that the system is accurate in switching,stable and realiable in high-speed running with a good engineering practice reference.