Disclosed is a method of controlling an air supply system for a fuel cell. The air supply system includes a fuel cell stack, an air channel to supply air to an inlet of the fuel cell stack, a gas adsorption unit disposed on the air channel and configured to adsorb oxygen contained in air introduced into the air channel. In particular, the method includes: determining whether a power generation operation of the fuel cell stack is resumed; when the power generation operation of the fuel cell stack is resumed, controlling a voltage source to apply a voltage to the gas adsorption unit; and supplying air to the fuel cell stack through the air channel in a state in which the voltage is applied to the gas adsorption unit.

A fuel cell system includes a fuel cell and a fuel cell controller. The fuel cell controller is configured to control a cooler based on a command from a host controller, the cooler being configured to cool the fuel cell. When a predetermined condition regarding the fuel cell is satisfied, the fuel cell controller controls the cooler according to a procedure predetermined in the fuel cell controller, regardless of the command from the host controller.

A fuel cell system includes a fuel cell and a fuel cell controller. The fuel cell controller is configured to control a cooler based on a command from a host controller, the cooler being configured to cool the fuel cell. When a predetermined condition regarding the fuel cell is satisfied, the fuel cell controller controls the cooler according to a procedure predetermined in the fuel cell controller, regardless of the command from the host controller.

When a time point of occurrence of a stop state of a fuel cell system is predicted during traveling, a drying state control that causes a fuel cell stack to transition to a dry state is started a predetermined time (a required drying time) before the predicted time point of occurrence of the stop state.

When a time point of occurrence of a stop state of a fuel cell system is predicted during traveling, a drying state control that causes a fuel cell stack to transition to a dry state is started a predetermined time (a required drying time) before the predicted time point of occurrence of the stop state.

Methods and apparatus for reducing the tendency for mold formation and accumulation in membrane-based humidifiers used in PEM fuel cell systems can include reducing the oxygen concentration and/or generating hydrogen peroxide within the humidifier upon shutdown of a fuel cell system. In some embodiments, a fuel cell system comprises valves and lines located and operable to facilitate introduction of hydrogen into the humidifier upon shutdown of the system. In some embodiments, a fuel cell humidifier comprises a catalyst for promoting the generation of hydrogen peroxide from hydrogen and oxygen, and/or comprises acidic gas transport layers.

Methods and apparatus for reducing the tendency for mold formation and accumulation in membrane-based humidifiers used in PEM fuel cell systems can include reducing the oxygen concentration and/or generating hydrogen peroxide within the humidifier upon shutdown of a fuel cell system. In some embodiments, a fuel cell system comprises valves and lines located and operable to facilitate introduction of hydrogen into the humidifier upon shutdown of the system. In some embodiments, a fuel cell humidifier comprises a catalyst for promoting the generation of hydrogen peroxide from hydrogen and oxygen, and/or comprises acidic gas transport layers.

A fuel cell system includes a fuel cell stack of a plurality of power generation cells and an impedance measuring device for measuring the impedance in the fuel cell stack. When stopping the operation of the fuel cell system, a method for stopping the operation of the fuel cell system operates the plurality of power generation cells to generate electric power, until the impedance value becomes equal to or greater than an objective impedance value. After the impedance value has become equal to or greater than the objective impedance value, the operation stopping method still continues the power generation of the multiple power generation cells for a given period of time.

A fuel cell system includes a fuel cell stack, a reaction gas supply portion, and a control unit. The control unit performs two stages of purging that are a first purging and a second purging in which the flow rate of the reaction gas is smaller than the flow rate of the reaction gas of the first purging, and provides a purging standby time between the first purging and the second purging, and in a case in which an operation mode of the fuel cell stack when power generation of the fuel cell stack is stopped is a high output mode in which an output is higher than the output of a normal mode, the control unit makes a purging time longer than the purging time of the first purging that is performed in the normal mode.

A fuel cell module is configured or operated, or both, such that after a shut down procedure a fuel cell stack is discharged and has its cathode electrodes at least partially blanketed with nitrogen during at least some periods of time. If the fuel cell module is restarted in this condition, electrochemical reactions are limited and do not quickly re-charge the fuel cell stack. To decrease start up time, air is moved into the cathode electrodes before the stack is re-charged. The air may be provided by a pump, fan or blower driven by a battery or by the flow or pressure of stored hydrogen. For example, an additional fan or an operating blower may be driven by a battery until the fuel cell stack is able to supply sufficient current to drive the operating blower for normal operation.