Research on Sensorless BLDCM Control Strategy Based on Line Voltage Difference

The sensorless control strategy has become one of the important research directions of brushless DC motors. Researchers have proposed a variety of rotor position signal detection methods. Now, brushless DC motor position sensors usually use the back EMF to detect the zero-crossing point. While the zero-crossing point of the back EMF of the non-conducting phase winding is detected, and then delay 30° electrical angle to obtain the commutation time. But the method needs to reconstruct the neutral point of the motor with a certain error. In order to avoid the influence of the error, the paper studies and analyzes the rotor position detection technology based on the line voltage difference based on the traditional back EMF zero-crossing signal detection technology. Finally, a test platform based on STM32F103 development board was built. The feasibility of the method was verified by the actual operation of the motor.