Unified MANA-based load-flow for multi-frequency hybrid AC/DC multi-microgrids

Abstract

In islanded hybrid AC/DC multi-microgrids (MMGs), interconnected AC microgrids (ACMGs) can operate with their own frequency and power sharing strategy. Hence, to formulate the load-flow problem of multi-frequency islanded MMGs, conventional single-frequency load-flow approaches are not applicable. To this aim, in this paper a novel unified load-flow framework for AC/DC hybrid MMGs, is proposed. The principles of the proposed method are based on the modified augmented nodal analysis (MANA) formulation, which can be utilized for an arbitrary number of interconnected multiphase MGs. Then, an unbalanced MMG, which includes two ACMGs, one DC MG (DCMG), and two interlink converters (ICs), is used to verify the validity of the proposed MANA-based formulation.