摘  要：为了实现PWM-ON-PWM调制方式控制的无位置传感器无刷直流电机转子位置信号的检测，在分析了该种调制方式控制的功率逆变器为桥式结构无刷直流电机端电压的基础上，提出一种通过检测线电压差的过零点，移相30°电角度获得换相信号的方法，并以此得到了相应的检测电路。通过应用该检测电路搭建无刷直流电机控制系统的仿真和实验结果表明：提出的方法在宽速度范围内，特别是低速时都能准确地检测到转子的位置,从而验证了该方法的有效性。
关键词：无刷直流电机；换相信号；PWM-ON-PWM调制；反电势过零点；检测

Abstract: In order to achieve the rotor position signals for detection the senorless brushless DC motor of the PWM-ON-PWM modulation control,on the basis of analysis of terminal voltages for brushless DC motor with the bridge inverter on the types of modulation control,obtained a method commutation signals by detecting the line voltage difference zero crossings,then 30° phase-shifting was proposed and got to the corresponding detection circuit.Simulation and experimental results through the application of the detection circuit structures brushless DC motor control system show that the proposed method in a wide range of speeds,particularly when low-speed can accurately detect the rotor position,to verify the effectiveness of the method.
Key Words:Brushless DC motor;Commutation signals; PWM-ON-PWM modulation;Back-EMF zero crossings;Detection