A system engineering approach to low voltage DC distribution

This article focuses on the overall system engineering aspects of low voltage DC (LVDC) electricity distribution.. The interdependencies between different parts of an LVDC distribution system are discussed emphasising the issues related with the interconnection of user-end LVDC installations and public LVDC systems. The main objective is to illustrate the importance of the total system engineering over the piecewise design approach. The aspects affecting on the selection of the DC voltage level, system structures and earthing arrangements are considered. A methodology for selecting the techno-economic optimal voltage level within the boundary conditions set by the DC system application and the operating environment is introduced with example calculations. Presented discussions and results provide support especially for the development of the standardisation of the LVDC technology.