FUEL CELL SYSTEM AND METHOD FOR CONTROLLING FUEL CELL SYSTEM

A fuel cell system includes a solid oxide fuel cell capable of generating power by receiving a supply of a reformed gas and an oxidant gas; an oxidant gas supply device that supplies the oxidant gas to the fuel cell; a reforming unit that supplies the reformed gas to the fuel cell; a fuel supply device that supplies a fuel which is a raw material for the reformed gas to the reforming unit; a combustion unit that combusts discharged gases of the fuel cell, wherein the reforming unit can reform the fuel into the reformed gas by exchanging heat with a combustion gas produced by the combustion unit; and a first control unit controls the fuel supply device to additionally supply the fuel to the fuel cell through the reforming unit in order to prevent the oxidant gas from flowing in from downstream of a fuel electrode of the fuel cell at the time of stopping the system. The fuel cell system further includes a second control unit that controls to supply the fuel to the reforming unit before the additional supply so that the temperature of the reformed gas flowing into the fuel cell does not exceed a predetermined temperature at the time of stopping the system.