Islanding operation of DC smart grid under DC distribution line faults

Recently the smart grid has attracted attention with the introduction of renewable energies. The increased attention is due to the prevalent move to reduce the amount of greenhouse gases, which are released into the atmosphere. This paper consider DC smart grid. The DC distribution system has the following advantages over conventional AC systems. Because it is sufficient to control only the voltage of the DC distribution line, and there is no need for phase detection at the time of conversion such as is required by DC to AC conversion, many distributed generators may cooperate relatively easily. There are a number of advantages such as a reduction of necessary power conversion, resulting in a reduction of losses and the cost of the device. However, there is a lack in the number of publications regarding the study of protection systems and islanding operation methods at the time of a DC fault. Therefore, this paper presents an islanding operation method of a DC distribution system with smart grid technology. The simulation verifies that high quality power can be supplied without any problems when a fault occurs in the DC distribution system or the AC distribution system.