Coupled-Inductor-Based DC–AC Multilevel Converter With Reduced Number of Switches

Hybrid microgrids (HMGs) are attracting increasing interest in the electrical sector, driven by the need to enhance integration between alternating current (ac) and direct current (dc) sources and loads. The rising relevance of these microgrids (MG) originates from their ability to reduce the required conversion units, decreasing the complexity associated with the diverse characteristics of sources and loads. In this context, this study proposes a new topology for a hybrid bidirectional converter designed to serve as an interface between the ac and dc buses of an HMG, with specific applications in low-voltage distribution networks. The converter’s ac port is three-phase, including a neutral to enable the use of single-phase loads, and adopts a multilevel approach based on coupled inductors. The use of coupled inductors in the ac port aims primarily at reducing the output current ripple, thereby allowing a decrease in the output filter inductor. In the dc port, the converter shares the same neutral leg as the ac port, resulting in a reduction in the number of semiconductors. The simulation and experimental results validate the performance of the proposed converter, demonstrating a total harmonic distortion (THD) of 3.1% in voltages and currents.