Abstract: The traditional brushless DC motor has some problems such as obvious startup shaking and large torque ripple. To solve these problems,the space vector pulse width modulation strategy is proposed,and the sliding mode control is used to replace the speed loop PI control,while the optimal current vector is injected into the q-axis current loop. By building the simulation model and analyzing the simulation results,it can be seen that compared with the traditional control strategy,the starting overshoot can be effectively reduced,the commutation torque ripple can be suppressed,and the dynamic response ability can be improved.

Key words: brushless DC motor, space vector pulse width modulation, sliding mode control, optimal current vector, torque ripple