Method for controlling fuel cell system

A method for controlling a fuel cell system,

• the fuel cell system including
• a fuel cell that includes a membrane electrode assembly in which a solid polymer electrolyte membrane is sandwiched between an anode electrode and a cathode electrode and that generates electric power by causing an electrochemical reaction between a fuel gas that is supplied through a fuel gas supply channel to the anode electrode and an oxidant gas that is supplied through an oxidant gas supply channel to the cathode electrode,
• an oxidant gas supply mechanism that includes a rotational driving unit and that supplies the oxidant gas to the oxidant gas supply channel as the rotational driving unit rotates, and
• a pressure adjusting valve that adjusts a pressure in the cathode electrode,
• the method comprising:
• performing flow rate control so as to adjust a supply flow rate of the oxidant gas to the cathode electrode by adjusting an opening degree of the pressure adjusting valve while maintaining a rotation speed of the rotational driving unit at the lowest when
• the rotation speed of the rotational driving unit is the lowest,
• the oxidant gas supply mechanism supplies the oxidant gas at a lowest supply flow rate, and
• a required oxidant gas flow rate to the cathode electrode is lower than the lowest supply flow rate.