Inertia Emulation with Concept of Virtual Supercapacitor for Islanded DC Micro-grid

The expansion of renewable energy sources (RESs (and advances in power electronics have been led to more attention being paid to DC microgrids (DCMGs). DCMGs enable the exploitation of all renewable energy potentials. Along with the advantages of RESs and DCMGs, the use of RESs is associated with the challenges of absence or lack of inherent inertia. Inertia in the DCMGs plays an important role in reducing voltage changes under destructive events such as load change and power change. Therefore, by applying energy storage systems (ESSs) in DCMGs, and inertia emulation the mentioned challenges can be overcome. The proposed control scheme is implemented based on the concept of the virtual supercapacitor in the inner control loop of the ESS interface dual-half-bridge (DHB) converter with DCMG to emulate the inertia. Due to the high efficiency, electrical insulation, inherent soft switching, and the need for a smaller filter, the DHB converter has been used. Finally, a DCMG is simulated in MATLAB / Simulink. The simulation results show the efficiency and flexibility of the proposed scheme in terms of inertia emulation.