An AC/DC converter and a DC/DC converter are disposed corresponding to a power generator. The AC/DC converter converts AC power generated by the power generator into a generated voltage, and outputs the generated voltage to a power line. The DC/DC converter converts the generated voltage on the power line into a collection voltage, and outputs the collection voltage to a collection line. DC power in a DC voltage grid formed of the collection line is transmitted through a DC/AC converter to an AC power grid. When a short-circuit fault occurs in the DC power grid or the AC power grid, a control command value for the AC/DC converter or the DC/DC converter is adjusted so as to suppress incoming electric power flowing from the power generator in accordance with fluctuations of a collection voltage.