Low-Voltage ac and Low-Voltage dc Distribution Systems: An Assessment of Losses and Power Capacity considering the Penetration of Renewable Energy Sources

The arguments regarding the usage of dc instead of its counterpart in ac have been discussed for a long time. Aiming for an efficient connection interface for the insertion of renewable energy sources (RESs) on the grid and the reduction of distribution losses, the employment of a low-voltage dc (LVdc) distribution system is considered in this study. For this purpose, the modification of an original low-voltage ac (LVac) distribution system to a dc one, without network rerouting and with minimal adaptations, is proposed. Both systems were implemented in the electric power open source distribution system simulator OpenDSS (open source code) and compared regarding their losses, energy transferred to the loads, voltage drops along the line as well as the number of conductors required for their operation. Moreover, different dc/ac conversion efficiency levels required by the penetration of solar photovoltaic (PV) systems as a RES on the grid were investigated, highlighting the discussion regarding the performance of operation modes.