Sliding mode variable structure control design principles and application to DC drives

In this paper, a control system of DC motor for speed and torque control based on variable structure systems with sliding mode control approach is presented. The comparisons between classical and sliding mode techniques are investigated and their advantages and disadvantages are identified. The current limiter mechanism to limit the current during start-up, acceleration and deceleration for speed control loop is proposed and presented. The simulation results of the proposed controller show that the variable structure system with sliding mode control approach is superior in rejecting disturbance, has faster response and is less sensitive to parameter variations compared to the conventional PI controller.