FUEL CELL SYSTEM AND METHOD FOR CONTROLLING FUEL CELL SYSTEM

A fuel cell system supplies anode gas and cathode gas to a fuel cell and causes the fuel cell to generate electric power in accordance with a load. The fuel cell system includes a container reserved impurities discharged from the fuel cell. The fuel cell system includes a pressure control unit that makes a pressure of the anode gas higher when a current of the fuel cell is high than when the current of the fuel cell is low. The fuel cell system includes an estimation unit that varies the current of the fuel cell, and estimates a current-voltage characteristic of the fuel cell on the basis of a current value and a voltage value obtained when the current of the fuel cell has been varied. The fuel cell system includes a restriction unit that, while the estimation unit is estimating the current-voltage characteristic, restricts a reduction in the pressure of the anode gas.