Configuration and control of a DC microgrid for residential houses

DC microgrid is suitable for dc output type distributed generations and energy storages. In this paper, dc microgrid for residential houses is described. Electrical power through dc distribution line (± 170 V) can be converted into some proper ac or dc voltages by converters placed near loads. Each house has a cogeneration system such as gas engine or fuel cell. The outputs of those distributed generations are connected to dc distribution line, and the power from generations can be shared among residences. We constructed a small scale experimental system in our laboratory, and examined the fundamental characteristics of dc microgrid. The experimental results demonstrated that high quality power was supplied even when voltage sag occurred in the utility grid.