Design of phase lead compensator for buck converter fed adjustable speed drive

This paper addresses the dynamic modeling of buck dc-dc converter with separately excited dc motor load by average state-space analysis method. Based on these models, the speed of the machine is controlled using direct measurement of speed. Inductor value is calculated based on switching frequency to limit the current and torque ripple. Dynamic behavior is improved by designing the proper phase lead compensator using bode diagram, instead of PI controller. Hysteresis band controller and peak current controller are used for inner current loop for controlling the duty ratio of the switch. Performances of both hysteresis band controller and peak current controller are verified by MATLAB Simulation.