Distributed Adaptive Coordination of Flexibility Resources for Real-Time Power Balancing in Islanded DC Microgrids

Modern DC microgrids (DC-MGs) typically incorporate Renewable Energy Sources (RESs), energy storage systems, and local loads. In islanded DC-MGs, effective coordination of these components is essential for secure and reliable operation, given the intermittent nature of RESs and the uncertain demand profile. This paper employs electric spring topology to enhance flexibility through the smart management of both energy stored in batteries, and loads, in the case that the generation capacity of multiple RESs-operating with the Maximum Power Point Tracking (MPPT) algorithm-is insufficient to meet demand. Besides, a distributed adaptive droop-based scheme is designed concerning a trade-off between common bus voltage regulation and proper current/power sharing among units. This distributed scheme benefits from a low-bandwidth communication interface among the in-service units to collect required data for adaptive estimation of droop gains. To ensure reliable operation of the DCMG, batteries' capacity and State-of-Charge (SoC) information are also incorporated into the energy-sharing strategy, aiming to maintain SoC balance among storage units during replenishment. The feasibility of the proposed approach is evaluated through a Power-Hardware-in-the-Loop (PHIL) platform.