DC voltage level choice in residential remote area

Abstract

This paper presents an overview of DC voltage levels used for DC nanogrids in residential remote area. The DC bus is the common link between distributed sources and loads. As there are not yet requirements and standards for the DC microgrids, the DC voltage level was often made from previous experiences and best practices. The most common values are 12V, 24V, 48V, and 100V. In this context, this work targets to compare the consequences of these different choices on the DC nanogrid from one hand, and to establish a reasonable roadmap to help the appropriate choice of the DC bus from the other hand. This choice should allow reliability, safety, energy efficiency and cost saving. Hence, several criteria have to be considered, such as line thermal limits, voltage drop and power losses through the cables connecting local loads to DC bus. Finally, the proposed methodology was adopted for a small scale laboratory DC home nanogrid and the final choice of the DC voltage was a single bus of 48V.