Speed control of brushless dc motor using fuzzy logic controller

This paper presents a control scheme of a fuzzy logic for the brushless direct current (BLDC) permanent magnet motor drives. The mathematical model of BLDC motor and fuzzy logic algorithm is derived. The controller is designed to tracks variations of speed references and stabilizes the output speed during load variations. The BLDC has some advantages compare to the others type of motors, however the nonlinearity of the BLDC motor drive characteristics, because it is difficult to handle by using conventional proportional-integral (PI) controller. The BLDC motor is fed from the inverter where the rotor position and current controller is the input. In order to overcome this main problem, the fuzzy logic control is learned continuously and gradually becomes the main effective control. The effectiveness of the proposed method is verified by develop simulation model in MATLAB-Simulink program. The simulation results show that the proposed fuzzy logic controller (FLC) produce significant improvement control performance compare to the PI controller for both condition controlling speed reference variations and load disturbance variations. Fuzzy logic is introduced in order to suppressing the chattering and enhancing the robustness of the controlled system. Fuzzy boundary layer is developed to provide smother transition to the equivalent control. Smaller overshoot in the speed response and much better disturbance rejecting capabilities.