DC utilization of existing LVAC distribution cables

Low Voltage (LV) AC cables are predominant in distribution networks across the world. The possibility of transforming such networks to DC may hold significant advantages and it is widely being considered. In particular it may allow a greater flow of electrical energy within urban areas, allowing adoption of electrical vehicles and Smart Grid applications. Distribution networks in UK use well established 4-core Paper Insulated Lead Covered (PILC) belted cables as well as newer cross linked polyethylene (XLPE) screened cables. Optimal utilization of existing conductors in the cables is of paramount importance in order to fully take advantage of the infrastructure. DC can be applied using a unipolar or a bipolar configuration. Both configurations possess advantages in different situations therefore both are considered in this study. This paper investigates different scenarios and proposes the optimal configurations for an LVDC distribution network. The implications for optimizing power flow are considered.