Virtual Inertia Scheduling (VIS) for Microgrids With Static and Dynamic Security Constraints

Microgrids feature a high penetration of inverter-interfaced distributed energy resources (DERs). The low inertia characteristic and fast dynamics of DERs pose challenges to conventional decoupled static economic operation and dynamic control design within microgrids. Hence, this paper proposed virtual inertia scheduling (VIS) for microgrids, aiming to ensure both economy and security. First, a unified framework for device-level control and grid-level operation is introduced, with VIS serving as a key application to address low inertia issues. VIS actively harnesses the controllability and flexibility of DERs to effectively manage microgrid inertia. It updates the conventional economic operation framework by incorporating the virtual inertia/damping cost, transient performance constraints, and stability constraints. Control parameters for DERs are formulated as additional decision variables. Then, VIS is specified in microgrids, followed by explication and linearization of dynamic constraints. An efficient workflow is developed to integrate data-driven dynamics approximation and linearization into microgrid-VIS, involving data generation, cleaning, and labeling to alleviate computational burdens. Time-domain simulations are further integrated for correction, validation, and performance guarantee. Finally, VIS is verified in an islanded microgrid modified from the IEEE 123-bus system. Results demonstrate that VIS effectively addresses the low inertia challenges in DER-penetrated microgrids, balancing economic considerations and dynamic performance.