• Energy Research

Multiport power converters integrate three or more energy devices into a single (potentially highly controllable and efficient) hub. These characteristics suggest that multiport power converters may be valuable for the decarbonisation of distribution networks, where the increase of converter-interfaced devices has degraded system reliability and efficiency. This review analyses the suitability of a wide range of multiport power converter solutions for four example distribution network applications (where previous studies have focussed on a limited range of topologies or applications) and the research areas that can progress their maturity. A review of grid codes and standards overviews the base capability that multiport power converters are likely to require, some of which are carried forward as requirements for a novel comparison tool. The comparison tool is developed to qualify and score reviewed topologies in terms of a range of features that are weighted for the applications. Isolated and partially-isolated topologies perform well due to their flexibility to be configured for the specifications and their operational capabilities (including modularity and voltage decoupling). Further research should focus on the complex control interactions between ports and scaling of these topologies for medium voltages. In contrast, many direct current non-isolated topologies do not qualify due to their low flexibility to be configured for the applications. This suggests that future research could focus on the development of a more flexible non-isolated multiport power converter configuration to take advantage of the high efficiency and low footprint that these topologies might otherwise offer for low voltage applications. This project was funded by the Innovate UK Horizon Europe Guarantee application number 10039599. This work was also funded by the European Union's Horizon Europe research and innovation programme in the framework of the project “iPLUG” with grant agreement 101069770. . Peer Reviewed

This paper discusses bidirectional step-down topologies that enable the interface of the 400V unipolar DC microgrid with the European low-voltage three-phase AC grid. The study compares three single-stage non-isolated topologies, namely, the seven-switch buck converter, Swiss converter, and Y-converter, based on semiconductor stresses and losses, magnetic component sizes and losses, and heat sink sizes. The analysis is conducted for a 10kW converter designed for small commercial or residential use. The results indicate that the Y-converter has superior overall performance compared to the other topologies, making it a potentially better candidate for this application. A 10kW prototype of the Y-converter is constructed. It is demonstrated to have a peak efficiency of 99.26% and an efficiency of 97.47% at the rated output power.