Physics-Inspired adaptive virtual inertia control for interconnected Multi-Voltage DC microgrids

In conventional power grids, inertia provided by rotating machines acts as an instantaneous energy storage source and plays a crucial role in maintaining frequency and grid stability. However, in DC micro-grid (DCMGs) based on renewable energy resources, natural inertia is absent. This lack of inertia can lead to voltage instability, poor response to sudden load changes, control challenges, and the need for energy storage systems. In this paper, two islanded DCMGs with different voltage levels are studied, which are interconnected through a bidirectional DC/DC interconnected converter (IC). The proposed power converter, using a novel control method based on physics-inspired Adaptive Virtual Inertia Control (AVIC), is capable of not only accurate power sharing between the two DCMGs but also compensating for the inertia deficiency of the DCMGs, stabilizing the DC voltages on both sides of the DC/DC-IC at their reference values, and mitigating interactions between DCMGs. In addition, a stability analysis and control parameters design are presented. Each DCMG presented in this paper is supplied by four different Distributed Generation (DG) units, Battery Energy Storage Systems (BESS), AC, and DC load units. Simulation results obtained in MATLAB/Simulink and conducted real-time experiments on an OPAL-RT platform demonstrate and validate the effectiveness of the proposed control strategy for DCMG interconnected systems.