Research on BLDCM Double Loop PWM Control Based on Positionless Sensor

Abstract

In order to solve the problem of positionless sensor drive control of brushless DC motors, a fuzzy PID algorithm and virtual sensors are proposed to detect the rotor position. The construction of the virtual sensor of this method is to combine the zero-crossing detection of the line back EMF and the principle of the sensor to detect the rotor position, instead of the traditional sensor. The fuzzy PID instead of traditional PID control is used to improve its accuracy. Though simulation verification, the method proposed in this paper is compared with the traditional brushless DC motor control with a position sensor. This method requires a shorter time to reach a steady state. The load speed is still maintained at a given speed after 0.02s after operation. The results show that the method proposed in this paper is faster in control than the traditional BLDCM, and provides a theoretical basis for BLDCM dual-loop PWM control without position sensor.