Enhancing robust control of DC-DC converters: adaptive super twisting control based on barrier function

This technical note introduces an innovative approach to address the challenges associated with designing robust controllers for DC-DC converters, particularly in scenarios where disturbances and their derivatives are unknown or difficult to quantify. Traditional robust controller designs rely heavily on precise knowledge of disturbance bounds, which may not always be practical. In response, this paper proposes an adaptive control strategy employing an Automatic Adaptive Gain Mechanism (AAGM) within a Super Twisting Control (STC) framework for SEPIC converters. The key contribution lies in the development of an Adaptive Super Twisting Controller (ASTC) utilising a barrier function to dynamically adjust controller gains without requiring prior knowledge of disturbance bounds or their derivatives. Through simulations and experimental validation, the efficacy of the proposed ASTC with AAGM is demonstrated in achieving robust performance under various operating conditions, including sudden changes in reference voltage, load variations, and input voltage fluctuations. The results highlight the capability of the ASTC with AAGM to optimise controller gains autonomously, thereby enhancing the converter's dynamic response, reducing output voltage ripple, and ensuring stability across a wide range of operating conditions.