Generalized proportional integral observer based backstepping control for DC-DC buck converters with mismatched disturbances

Considering load uncertainties in the DC-DC buck converter, the mismatched disturbances are imposed on the system, which would cause degradation of the control performance. Conventional backstepping control (BSC) scheme fails to achieve a high precision performance especially in the presence of strong disturbances. In addition, the disturbances caused by load uncertainties are complex in reality, which often turn out to be time series polynomial forms. Generalized proportional integral observer (GPIO) based backstepping control scheme is advocated in this paper to solve this problem. The GPIO based backstepping algorithm performs not only a promising disturbance rejection ability but also a nice property of tracking performance. A rigorous stability analysis for the closed-loop system is presented. The feasibility and efficiency of the proposed method is validated by both simulation and experimental results.