Optimal QFT controller and pre-filter for buck converter using flower pollination algorithm

Abstract

Buck converters are proficient second order step down DC-DC converters and are center to various applications that rely on constant load voltage under fluctuating input voltage. DC-DC converters operate either under voltage control mode or current control mode. These converters exhibit non-linear behavior due to switching, hence controller design comes with complexities and an ordinary linear converter offers a sluggish and highly deviant response. In this paper QFT based controller and pre-filter is designed for voltage mode controlled buck converter with parametric uncertainties for both variable input voltage and load variation. The QFT design problem has been formulated as an optimization problem and solved using flower pollination algorithm. The designed controller exhibits robust behavior under parametric uncertainties. MATLAB simulation has been carried out for the converter and simulation results verify the robustness of the controller for large input voltage and load variations.