New sliding mode controller design for a DC to DC buck power converter in the presence of matched and mismatched disturbances

This paper presents a novel sliding mode controller based on an extended state observer (ESO) in the presence of matched and mismatched disturbances for a DC–DC Buck converter. Firstly, stability of ESO is roved by introducing a proper Lyapunov function. Then, by proposing a sliding surface containing system and ESO states, a novel nonlinear controller is designed to satisfy sliding condition. The proposed controller shows a superb disturbance attenuation which guarantees finite time stability of the closed-loop system. Moreover, reaching time to the sliding surface is analysed and upper bound of this time is obtained. Finally, simulation results and comparisons with previous research works reported in the literature demonstrate superiority of the proposed method.