A Robust PI-Lag Compensator for DC-DC Buck Converter Fed DC Motor Drives

In recent years, the precise control of DC-DC buck converter fed DC motor has gained significant attention due to its high exceptional speed control capabilities. The traditional proportional integral (PI) controller used for controlling the DC motor exhibits high oscillation, increased settling time, and poor dynamic response. This paper introduces a novel approach by integrating a PI controller with a lag compensator for controlling DC motor powered by dc-dc buck converter. The proposed design adopts a frequency domain approach, employing a PI controller and a lag compensator in series. In this proposed PI–lag compensator, the PI controller reduces the steady-state error (SSE) and minimizes the torque ripples. On the other hand, the lag compensator enhances the transient response of the system. This combined PI-lag compensator ensures optimal gain crossover frequency (GCF) and phase margin (PM), maintaining optimum performance for the buck converter fed DC motor. To validate the efficacy of the proposed compensator, a comprehensive comparative analysis is conducted against different controllers, including fuzzy proportional integral derivative (PID), hysteresis band, and peak current controller. The MATLAB/Simulink environment and a laboratory scale experiment are utilized to validate the performance of the proposed PI–lag compensator.