DC power systems: Challenges and opportunities

The ever increasing penetration depth of Distribution Energy Resources (DER) and the development of power electronics devices have a significant impact on the development of DC power transmission and distribution systems. This paper provides an overview of the recent advancement and also envisioned research and development on DC grids, with the objective of identification and discussion of the corresponding issues. Brief descriptions of DC grids at various voltage levels and their benefits are presented and discussed. Different layouts for the DC grids are presented and the associated technical issues are highlighted.