FUEL CELL SYSTEM AND CONTROLLING METHOD OF SAME

A fuel cell system comprises a solid oxide fuel cell which generates a power by receiving a supply of an anode gas and a cathode gas. The system comprises a cathode gas supply unit to supply the cathode gas to the fuel cell via a cathode gas supply route; a first burner arranged in the cathode gas supply route, a second burner to burn an anode off-gas and a cathode off-gas, which are discharged from the fuel cell; a first branch path which is branched out from an upstream of the first burner and joins to a downstream of the first burner in the cathode gas supply route; and a second branch path which is branched out from a downstream of the first burner in the cathode gas supply route and joins to a cathode off-gas discharge route through which the cathode off-gas is discharged from the fuel cell to the second burner.