Abstract: The present disclosure stabilizes power generation of a fuel cell stack in an environment in which an oxygen concentration in a fuel cell system readily decreases. In a case where it is detected that the oxygen concentration is lower than a predetermined concentration or where a phenomenon caused by the oxygen concentration being lower than the predetermined concentration is detected, processing to increase a flow rate of air supplied to the fuel cell stack or processing to ventilate the interior of the fuel cell stack by controlling an operation of a ventilation unit is performed.

Abstract: A fuel cell system 1 includes a fuel cell FC having a plurality of fuel battery cells, a control unit Cnt configured to control power generation of the fuel cell FC, a power storage apparatus S, and a DCDC converter Cnv. The control unit Cnt makes the voltage of the fuel cell FC higher than the voltage of the power storage apparatus S when the power generation by the fuel cell FC is stopped and makes the power generated in the fuel cell FC when the power generation by the fuel cell FC is stopped chargeable to the power storage apparatus S through a first path having diodes D1, D3, D5.

Abstract: In a fuel cell system, a controller is configured to, to stop the fuel cell system, (a) execute an oxidizing gas consumption process by supplying a fuel gas to an anode and sweeping current from a fuel cell while a supply-side on-off valve and an exhaust-side on-off valve are closed to seal the remaining oxidizing gas in the cathode, and (b) stop sweeping the current at a time point at which the difference between pressure of the cathode that decreases in response to the sweeping of the current and an estimated pressure value of the cathode that decreases by consumption of the oxidizing gas remaining in the cathode in response to the sweeping of the current becomes larger than a predetermined determination threshold value to end the oxidizing gas consumption process.

Abstract: In a fuel cell system, a controller is configured to, to stop the fuel cell system, (a) execute an oxidizing gas consumption process by supplying a fuel gas to an anode and sweeping current from a fuel cell while a supply-side on-off valve and an exhaust-side on-off valve are closed to seal the remaining oxidizing gas in the cathode, and (b) stop sweeping the current at a time point at which the difference between pressure of the cathode that decreases in response to the sweeping of the current and an estimated pressure value of the cathode that decreases by consumption of the oxidizing gas remaining in the cathode in response to the sweeping of the current becomes larger than a predetermined determination threshold value to end the oxidizing gas consumption process.