Performance Evaluation of Multiport Y-Converters Using Renewable Source Mission Profile

The integration of distributed energy resources (DERs) into electrical grids demands efficient dc-ac interfacing solutions. This work focuses on the design and optimization of converter topologies for such integration, particularly for interconnecting 400 V dc microgrids (MGs) with the European lowvoltage ac grid. The Y-converter topology is investigated, offering single-stage power conversion and bidirectional buck-boost capability. Two design approaches are evaluated: employing separate two-port Y -converters (2 Y) and utilizing a single, integrated multiport Y-converter (MPC). A Pareto optimization framework is applied to explore trade-offs between efficiency and power density, based on detailed analysis of component losses, volume, and design constraints. Results show that both approaches achieve high efficiency and power density, with the MPC exhibiting superior average efficiency for dc power transfer by avoiding additional losses introduced by the intermediate ac stage present in the 2 Y configuration. These findings demonstrate the strong potential of MPCs as compact and efficient interfaces for future dc MGs integration with the ac grid.