Loss evaluation of DC distribution for residential houses compared with AC system

In this paper, loss of a dc microgrid system for residential complex is compared with loss in an ac system. Each system has a PV system, a gas engine cogeneration and 20 residential houses. The losses are calculated from measured load data and PV output data which was estimated from global solar radiation and temperature of a PV panel. The operation of the gas engine cogeneration is determined from the heat demands. As house loads, we consider an air conditioner, a refrigerator, a washing machine and a liquid crystal display (LCD) in each house. The loss calculation result shows the total losses in the dc system are around 15% lower than the losses in the ac system.