Cost-Based Adaptive Coordination of Battery Energy Storage Systems in DC Microgrid

This paper proposes a novel droop control strategy to reduce battery degradation costs in islanded DC microgrids (DC-MGs) with multiple Battery Energy Storage Systems (BESSs). Due to differences in battery types, capacities, and rated power, each BESS may have unique installation costs and cycle life characteristics, leading to unequal degradation costs even when delivering the same amount of energy. So, to ensure the economic operation of batteries, the proposed method leverages the concept of Incremental Cost (IC), derived from battery lifecycle data, to quantify degradation cost. This cost metric is then used to automatically allocate each BESS's power contribution by adjusting the droop gains within the control mechanism. The resulting IC-based droop control adaptively balances ICs across all BESS units, thereby minimizing total degradation costs. The effectiveness of the presented method in reducing the overall degradation costs of the batteries has been verified through simulation scenarios using MATLAB ® /Simulink.