A torque control strategy of brushless direct current motor with current observer

This paper presents a torque control strategy of brushless DC (BLDC) motor based on current observer and state feedback control algorithm. Based on establishment and in depth analysis of the BLDC mathematical model, BLDC motor torque control is transformed into BLDC motor current control. Then a full dimensional current state observer is designed to estimate armature current of BLDC motor. After observing armature current with current state observer, it is fed back to the feedback state controller and the current reference input port to generate current control signal and current error signal, respectively. The control signal and error signal can be used to control the torque of BLDC motor. After completing the torque control algorithm of BLDC motor, a simulation model is developed using Matlab/Simulink. The capability and performance of the torque control algorithm of BLDC motor is verified.