A Hierarchy of Models for Inverter-Based Microgrids

Abstract

This work develops a hierarchy of models, each with distinct time resolutions, for microgrids having grid-feeding inverters at all generation buses. Specifically, our focus is on microgrids with battery storage units connected to an electrical network via grid-feeding in- verters. The process of developing the model hierarchy involves three key stages: (1) the formulation of a microgrid high-order model using circuit-theoretic and control laws, (2) the systematic reduction of this high-order model to distinct reduced-order models using singular perturbation techniques, and (3) an identification of the time resolutions for which each reduced-order model is valid. A comparison between the responses of all the models developed and that of a microgrid ultra-high fidelity model is presented.