An Integrated Disturbance Observer-Based Adaptive Smooth Gain Sliding Mode Control for DC/DC Converters in DC Microgrids

Large signal perturbations, such as abrupt load changes and sudden voltage surges, pose significant challenges to the stable operation of DC microgrids. Various control strategies have been explored to mitigate these disturbances. Among them, terminal sliding mode control (TSMC) offers a rapid dynamic response, but its inherent chattering and limited disturbance rejection capabilities hinder its effectiveness in DC microgrid applications. To address these issues, this paper proposes a novel adaptive smooth gain terminal sliding mode control (ASTSMC) strategy for the outer voltage loops of DC-DC converters. In addition, a reduced-order error-based extended state observer (REESO) is integrated to enhance disturbance estimation, mitigate the effects of disturbances, and improve the computational efficiency. The proposed ASTSMC-REESO approach effectively tackles the inherent chattering issues of TSMC, achieving superior voltage control performance under severe disturbances. Experimental results demonstrate that the proposed strategy significantly improves the performance of voltage regulation in DC microgrids.