A Comparative Study on Voltage Level Standard for DC Residential Power Systems

With the increasing demand for renewable energy integration and DC power consumption, the application and investigation of residential low voltage DC (LVDC) power system have attracted more attention in recent years. The residential DC power system has advantages on distributed generation integration and conversion cost reduction, which could provide high efficiency and high power quality power supply to consumers. However, the lack of voltage level standards challenges the commercial application of the LVDC power system. In this paper, a comprehensive study on the performance of different voltage levels is proposed, in order to provide a voltage level guidance for DC power supplier and appliance manufacturer. Existing voltage selections from applications and researches are compared with each other in terms of voltage compatibility, topology, power supply capability and electrical safety. Comparative simulation is conducted in the residential DC power system model of a community with four household subsystems. Based on the simulation and investigation, the comparison result indicates that: 240V and 380V is optimal for the unipolar residential system with low power demand and ±375V bipolar DC system should be used in heavy load scenarios.