A Trilateral Inertia Supporting Scheme for Hybrid AC/DC/DS Microgrids

The integration of large-scale power electronic converters into hybrid AC/DC/DS microgrids results in a reduction of system inertia, presenting operational risks and challenges. Virtual synchronous generators (VSGs) technology is proposed to solve this problem. However, the DC link capacitors connected to the power converters limit the realization of VSGs. The buffer power provided by capacitors is limited, and the power of distributed energy resources (DERs) is characterized by volatility and indirectness. In contrast, energy storage systems (ESS) with rechargeable and partially controllable capabilities exhibit greater potential for the practical application of VSG. In addition, the deployment of VSG can only respond to the load fluctuations of the subgrid where it is located, while using global inertia resources to respond to the power demand of any subgrid is undoubtedly more desirable. To full up this gap, this paper investigates the potential of distributed storage (DS) subgrids to provide virtual inertia in hybrid AC/DC/DS microgrids. Building on this foundation, a trilateral inertia support scheme is proposed, fully leveraging global inertia resources to smooth the hybrid system transient response. The feasibility and effectiveness of proposed scheme is verified by hardware-in-the-loop (HIL) experimentations.