Research on Dynamic Compensation Control of Bidirectional DC Charging Piles in DC Microgrid Systems Based on Disturbance Observer

This paper tackles the bus voltage control challenge in DC microgrids with bidirectional DC charging piles by designing a novel dynamic compensation strategy based on a disturbance observer. It aims to achieve precise voltage regulation for the DC-DC converters in these charging piles. Following an analysis of the post-access DC microgrid system architecture and the mechanisms of bus voltage fluctuations, a state-space model for the bidirectional DC charging pile's DC-DC converter was developed to clarify the input-output relationships. Based on disturbance bipartite decomposition and Youla parameterization theories, a control architecture with a disturbance observer was designed. Model matching theory was used to compensate for output disturbances caused by current fluctuations. The voltage loop compensation controller was solved using linear matrix inequalities (LMI), and the current loop compensation controller was designed based on the converter's dynamic structure diagram. The semi-physical simulation results confirm that this architecture enhances the DC-DC converter's dynamic performance without altering the original system parameters, suppresses DC bus voltage fluctuations from various factors, and significantly improves the system's disturbance rejection capability.