Mitigating GFM-induced Battery Stress with a VDCM-controlled Hybrid Energy Storage

In a power system dominated by inverter-based resources (IBRs), maintaining system stability is challenging without the support of an energy storage system. This study proposes a degradation-aware voltage-dependent current management (VDCM) battery–supercapacitor hybrid energy storage system (HESS). The hybrid configuration leverages the high energy density of batteries and the fast response and high-power density of supercapacitors to manage both moderate and rapid power fluctuations. By shifting fast charge–discharge activities to the supercapacitor, the system reduces stress on the battery and improves its ability to withstand abrupt frequency fluctuations. Simulation results demonstrate that the proposed control strategy not only effectively regulates voltage and frequency variations in the power system but also minimizes battery degradation while enabling grid-forming capabilities.