A Decentralized Power Allocation Strategy for the Hybrid Energy Storage System Toward Large-Signal Stability

This paper presents a decentralized power allocation strategy relying on the droop control for hybrid energy storage systems (HESSs) in DC microgrids (DC MG), which are composed of batteries and supercapacitors (SCs). The proposed approach employs virtual impedance injection to enable dynamic power allocation between storage units. Then, a sliding mode control (SMC) technique is developed. This technique is essential for the HESS as it significantly strengthens the large-signal stability characteristics, especially when the system encounters constant power loads (CPLs). Finally, simulations are conducted on the system under study. These simulations have successfully validated the efficacy of the proposed strategy.