Variable structure control for dynamic power-sharing and voltage regulation of DC microgrid with a hybrid energy storage system

摘要

This study proposed a novel method based on variable structure control for sharing power between battery and supercapacitor (SC) energy storage devices to address demand-generation disparity and DC bus voltage regulations. It allows for moderate and fast compensations using hybrid energy storage devices, ranging from batteries to fast SCs controlled by battery current error signals. The proposed method using hybrid energy storage devices controlled by proportional integral (PI) and variable-structured controllers enhances DC bus regulations with the reduced stress levels of batteries. Furthermore, redirecting unwaged battery currents toward SCs for fast compensation enhances the lifespan of batteries. The effectiveness of the method has been analyzed using simulations and compared with a conventional control method in terms of peak DC bus voltage deviations. The results were experimentally validated using a real-time hardware-in-loop (HIL) simulator based on a field-programmable gate array.