Moving towards a methodology for conductor sizing and protection in LVDC microgrids

Future power systems will be increasingly evaluated on their overall efficiency and sustainable use of raw materials. From this point of view, low-voltage DC networks have distinct advantages over AC networks. A large research interest is noted where these benefits are highlighted through case studies and demonstrators worldwide. However, the protection of DC networks is very challenging due to the absence of natural zero-crossings and fast network dynamics, and a general design methodology is missing in literature. This paper presents a general design methodology for the dimensioning of conductors and design of their protection in LVDC grids, in order to work towards a set of universal design methodologies for the development of LVDC grids based upon standards, best practices and experience, as is already a common resource in AC. The methodology is verified through a case study, where the differences with AC are highlighted and recommendations are made for standardization committees.