Finite‐time disturbance observer based non‐singular terminal sliding‐mode control for pulse width modulation based DC–DC buck converters with mismatched load disturbances

This study investigates a finite‐time disturbance observer (FTDO) based non‐singular terminal sliding‐mode control (NTSMC) approach for pulse width modulation based DC–DC buck converters subject to matched/mismatched resistance load disturbances. Considering the mismatched resistance load disturbance which does not act in the same channel as the control input, a novel non‐singular terminal sliding‐mode manifold incorporating with a disturbance estimation technique is designed. A FTDO‐based NTSMC method is introduced for DC–DC buck converter systems. A rigorous finite‐time stability analysis is also presented. As compared with the nominal NTSMC and existed SMC+ extended stated observer (ESO) method, the proposed method obtains a better disturbance rejection ability no matter the disturbances satisfy the so‐called matching condition or not. Simulation and experimental comparison results are implemented to verify the effectiveness of the proposed control method.