Robust Control of Buck Converter using H-infinity Control Algorithm

In this paper, an output feedback H-infinity (H-infinity) control algorithm has been proposed for a pulse-width modulation (PWM) based DC-DC buck converter. Here the design objective is to control the output voltage of the buck converter with minimum transient current. Using concept of Linear Matrix Inequality (LMI), mix-sensitivity H-infinity controller has been designed for the system. The closed-loop system tracks the reference voltage with minimum overshoot, undershoot and moderate settling-time. The performance of the controller is tested in presence of parameter variation and external noise. The controller also yielded robust performance with lesser amount of transient current than the other designed controller reported earlier.