Universal Interlinking Converter for DC-Powered Prosumer Buildings

With the increasing adoption of dc power distribution in both residential and commercial electrical installations, the need for a universal power electronics interface capable of connecting either single-phase or three-phase ac systems to dc-powered buildings is becoming more critical. While 230 Vrms and 400 Vrms remain standard voltages on the ac side, 350 Vdc has emerged as a widely accepted standard for dc distribution inside building, in accordance with the NPR 9090 and Current/OS protocols. Additionally, bipolar ±350 Vdc has been gaining traction due to their ability to scale to higher power levels while maintaining the same safety standards as lower-voltage unipolar ones. These trends highlight the increasing demand for highly efficient and flexible power electronics interfaces that can support at same time, a wide range of ac and dc voltage levels, including unipolar and bipolar configurations. To address these needs, this paper proposes a universal interlinking converter (ac-dc) capable of operating with both single-phase and three-phase ac sources, as well as with unipolar and bipolar dc microgrids. The proposed solution addresses a wide range of applications with a single, adaptable hardware platform. To validate the concept, a 5-kW prototype was developed and tested. Experimental results show that the proposed converter maintains stable operation in different modes, remains fully functional under fault conditions, such as the disconnection of one or two phases, as well as operating with both unipolar and bipolar dc microgrids with natural voltage balancing. These results validate the proposed converter as a universal solution capable of covering a wide range of applications.