Design of single closed loop control for chopper fed DC motor drive using IMC principles

In this paper, a simplified speed control design of chopper fed Direct Current (DC) motor drive with single feedback control structure is proposed. First, Internal-Model-Control (IMC) is used to control speed without closed loop current control scheme. Then, an analytical method based on IMC principles is applied to design a single-loop IMC controller with a Proportional-Integral-Derivative (PID) form. Finally, a comparative study has been done to highlight the benefits of the newly developed designs over the conventional control structure which has two PI controllers, one for controlling current and another for speed. The simulation results indicate that our proposed control schemes have good performance and robustness with appropriate safety for the DC drive system under steady and variable operating conditions, and in the presence of motor parameter variations.