Enhancing DC microgrids integration with three-phase AC grids using multiport converters

DC microgrids offer a promising solution to meet the escalating demand for electric energy by facilitating the integration of renewable energy sources, energy storage, and loads. To enhance the stability and sustainability of DC microgrids, a bidirectional power interface with the utility grid is adopted. This paper proposes a non-isolated multiport converter that interfaces multiple DC microgrids with a three-phase AC grid, potentially allowing reductions of overall size and cost compared the multi-converter approach, and providing additional flexibility by allowing for a direct power exchange between the DC microgrids. The main objective of the study is to validate the superior performance of the proposed converter compared to the conventional approach of interconnecting DC-DC and AC-DC converters in a cascaded connection. The study comprehensively evaluates semiconductor device stresses, losses, total chip area, and magnetic element size for both approaches. Finally, experimental results of the proposed converter are presented.