Experimental Validation of Voltage Regulation in Buck Converters through Fractional-Order PID Approximation

Abstract

Viability of a fractional-order PID approximation regulating voltage in buck converters through a single control loop is investigated. Fractional calculus approach is suggested due to it exhibits good robustness against parameter variations. The non-integer approach is integrated in the control strategy through a Laplacian operator biquadratic approximation to generate a flat phase curve in the system closed-loop frequency response, which results in the generation of the iso-damping characteristic. The synthesis and tuning process consider both robustness and closed-loop requirements to ensure a fast and stable regulation characteristic. Experimental data obtained with the resulting controller, which was easy implemented through RC circuits and OPAMPs in adder configuration, confirmed its effectiveness. Superiority of proposed approach, which is determined through a comparison with typical PID controllers, confirms its viability to be used in highly efficient converters, such as Silicon-Carbide ones.