Exploring the Features of Power Electronic Converters for Hybrid AC-DC Microgrids

Hybrid AC-DC grids are likely transitional solutions toward more sustainable, efficient, and cost-effective power systems. With the increasing utilisation of distributed resources, such as wind turbines, photovoltaic panels, and battery storage systems, direct current (DC) grids promise simpler integration and fewer conversion stages. While AC grids are based on mature technologies, DC grid technologies are still in the development phase and require broader considerations beyond niche applications. Many conventional converter topologies can already be utilised but also further extended with new features to meet the specific requirements of DC grids. In this context, at EPFL, a fully operational low-voltage hybrid AC-DC microgrid has been developed within the framework of the European project HYPERRIDE. Details of this development are presented in this paper. In particular, the specific features developed and deployed in AC-DC and DC-DC converters are discussed in detail.