PID control which has integrator

causes motor system response slow.Differences are shown between waves of phase-voltage and ideal square wave related to the influence of inductance in reversing process

leading to large torque ripple and slow response of speed.An optimized design of control system based on dynamic soft variable structure control is presented

by changing the control strategy of soft variable structure

and combining the stable linear system.Results of simulation experiments show that dynamic soft variable structure control compared PID control is with better performance

fast in speed response and small torque ripple.Dynamic soft variable structure control also can be applied to optimize the design of other control systems.