Towards a DC distribution system - opportunities and challenges

The increasing amount of distributed energy resources requires significant changes to today´s power systems. Most of the distributed resources are dc inherently or have a dc link. Therefore, connecting them with a dc distribution system seems beneficial. This paper presents the opportunities and challenges of dc distribution systems, starting with the requirements of future power systems. It will be looked at how dc can fulfill them with meshed grid architectures, increased system availability and new market models. New protection strategies for large dc distribution systems and their open research questions are discussed.