Robust barrier-based integral sliding mode control design for switched buck-converter system

This study focuses on robust control of Switched Buck Power Converters subjected to parametric uncertainties. A Barrier function-based integral sliding mode control (ISMCBF) scheme has been designed to fuse the barrier function within the control structure of integral sliding mode control (ISMC). The result of this integration is to obtain a robust sliding mode controller that could compensate for the parametric uncertainties without the need for prior knowledge of the disturbance. In conventional ISMC, the effect of perturbations is mitigated by including perturbation observers to estimate these uncertainties such as to compensate for them within the inner feedback loops. Unlike the conventional ISMC method, the proposed ISMCBF does not require advance knowledge of disturbance bounds or estimates to achieve robust characteristics. Rigorous stability analysis based on Lyapunov thereom has been conducted to ensure asymprotic convergence of dynamic errors. Simulation-based comparative analysis has been made between the proposed ISMCBF and conventional ISMC. The results showed that a reduced peak error (1.95 mV) has been obtained with a percentage reduction of 12.33% in control signal amplitude, and faster tracking response (0.08 sec) are the outcome of the proposed controller. Such results verified that the ISMCBF is a promising robust controller to be applied for DC-DC converters under variations in device parameters.