一种改进的无刷直流电机无位置传感器控制方法

An Improved Position Sensorless Control Method for Brushless DC Motor

针对无刷直流电机的传统无位置控制方法存在启动时检测困难、滤波电路导致相位延迟等问题,提出在上桥臂采用脉冲宽度调制且导通(H_PWM_ON)时,同时下桥臂恒通(L_ON)期间,将非导通相端电压与中性点电压进行比较,得到换相点实现绕组切换检测。该方法无需滤波电路,并具有在启动电机时克服传统方法缺陷的特点。研究结果表明:该方法运用在无位置控制中,电机能在0.2 s内迅速启动并且运行平稳。

The traditional position-free control method of brushless direct current( DC) motor has some problems,such as difficulty in starting detection and phase delay caused by filter circuit.In order to solve this problem,it was proposed that when the upper bridge arm was modulated by pulse width and conducted( H_PWM_ON),at the same time the lower bridge arm always conducte( L_ON),the phase switching point was aquired to realize winding switching detection by comparing the voltage of the non-conducting phase end with that of the neutral point. This method does not need filtering circuit and has the characteristic of overcoming the defect of traditional method when starting the motor.The research results show that this method can be used in the no position control,and the motor can start up quickly in 0.2 s and run smoothly.