Abstract: The speed loop of traditional brushless DC motors is easily affected by changes in internal and external parameters during operation,resulting in problems such as large commutation torque ripple. To solve these problems,space vector pulse width modulation （SVPWM） is used instead of PWM modulation. A control scheme is proposed,which uses fast super-twisting sliding mode control for the speed loop instead of PI control and injects optimal current vector into the q-axis current. By building a simulation model and analyzing the simulation results,it can be seen that compared to the traditional control strategy,this method can effectively reduce startup overshoot,improve dynamic response capability,and suppress commutation torque ripple.

Key words: brushless DC motor, space vector pulse width modulation, fast super-twisting sliding control, optimal current vector, torque ripple