A Fully Filter-Based Decentralized Control With State of Charge Balancing Strategy for Battery Energy Storage Systems in Autonomous DC Microgrid Applications

State of charge (SoC) imbalance and dc bus voltage deviations are significant issues for distributed battery energy storage systems in autonomous microgrid applications. Accordingly, a high-pass filter (HPF) based SoC balancing method is proposed to achieve balance by considering different SoCs capacities; A band-pass (BPF) power droop control used accomplish power-sharing compensation. Through this approach, units (BSUs) with higher capacity deliver more during discharging mode than those lower capacity. During charging mode, BSUs controlled absorb less SoC. Therefore, can be achieved between BSUs. Further, the maintained within desired range adopting method. In addition, employed also considers impact line resistance. The strategy implemented fully decentralized way which does not require any communication link, while maintaining system stability. MATLAB/Simulink processor-in-the loop (PIL) simulation results verify that effective feasible.