Robust Load Disturbance Rejection in PWM DC - DC Buck Converters

This article presents a novel approach to robust load disturbance rejection in DC-DC buck converters. We propose a novel control scheme based on the design of two nested feedback loops: the outer loop is designed using H∞ optimal control to achieve output tracking and robust stability, while the inner loop includes a novel load estimator-compensator scheme to improve the system response to output load disturbances. Robust stability of the entire control system is theoretically analyzed. The proposed scheme is compared with well-established disturbance-rejection methods, demonstrating its advantages through numerical simulations. Finally, we demonstrate the practical feasibility of the proposed method through experimental results obtained from a prototype evaluation board.