Ultra-High Step-Up Quadratic DC-DC Converter with Soft Switching, High Efficiency, and Cost Effectiveness for DC Microgrid Applications

This study presents a novel ultra-high step-up (UHSU) DC-DC topology tailored for applications in DC microgrids. The proposed configuration utilizes a quadraticbased topology, achieving a remarkably high voltage gain by elevating the turn ratio of the coupled inductor (CI). Notable advantages of this design include its capability to achieve ultrahigh voltage amplification, reduced diode reverse recovery losses, minimized voltage stress on switching components, continuous input current flow, and a shared ground connection linking the input and output. Additionally, the converter is equipped with soft-switching functionality for some of semiconductor elements, which significantly boosts efficiency and minimizes energy dissipation. By maintaining low voltage stress on the switches, the system ensures enhanced operational reliability and overall performance. The operational principles of the converter are analyzed in detail, and its effectiveness is highlighted through a comparison with other existing topologies. Finally, the proposed design’s performance is confirmed through the fabrication and experimental validation of a 400-W prototype, performing at a switching frequency of 50 $\mathbf{k H z}$, with an input voltage of $\mathbf{3 0} \mathbf{V}$ and an output voltage of 360 v.