Design of Control System for BLDCM without Position Sensor

摘要

The rotor position detection of brushless DC motor(BLDCM) without position sensor is studied. According to the mechanical structure and control characteristics of brushless DC motor ,The method of detecting the back electromotive force by zero-crossing is used to model and simulate the position sensorless control system of the brushless DC motor by citing a method of detecting the position of the rotor to obtain the position of the rotor. A mathematical model of the three-phase brushless DC motor was established, and the simulation model of the control system was established in MATLAB/Simulink. The motor armature current, back electromotive force, motor speed, etc. are analyzed at a given speed and variable load. The feasibility of the above control method is verified by experiments, and the normal operation of the brushless DC motor without position sensor in the full speed range is realized.