A pressurized air supply system supplies, to a pressurization object device, flowing air that includes at least one of compressed air, which is generated by compressing air supplied from an air supply source, or discharged air from a turbocharger compressor forming a turbocharger. The compressor is controlled such that a saturated steam temperature of the flowing air supplied from the air supply source to the pressurization object device is lower than a temperature in the pressurization object device, at startup.

A fuel cell system includes a membrane electrode assembly, an anode-side internal passage, a cathode-side internal passage, an oxygen supply section, and a control device. The oxygen supply section includes a gas circulation passage connected to one end side and the other end side of the cathode-side internal passage, an oxygen supply source connected to the gas circulation passage, and a gas circulation device configured to circulate and flow oxygen gas in any one of one direction and the other direction in the gas circulation passage. The control device switches a flow direction of the oxygen gas by the gas circulation device according to a distribution state of moisture on the cathode electrode of the membrane electrode assembly.

A method for humidifying a reactant in a fuel cell system is provided having a fuel cell stack, which is fluidically connected to a humidifier, wherein the humidifier comprises a membrane, on whose surface channels are formed. At least one of the channels is associated with a storage element for temporary storing of liquid water, the method involving the following steps: extracting the liquid water from the fuel cell stack and feeding the liquid water to the humidifier, admitting at least part of the liquid water into the storage element and temporarily storing the part therein, at least partially emptying the storage element by evaporating of the liquid water and humidifying of the reactant being supplied to the fuel cell stack by means of the evaporated liquid water, wherein the liquid water is extracted from the fuel cell stack both at the anode side and at the cathode side. A fuel cell system for carrying out the method is also provided.

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 systems are provided for a cooling system for a vehicle having a fuel cell system. The cooling system comprises a first cooling circuit configured to cool a first set of vehicle components and a second cooling circuit configured to cool a second set of vehicle components. The fuel cell system is distributed between the first set of vehicle components and the second set of vehicle components.

In a fuel cell vehicle and a method of controlling the fuel cell vehicle, when a gas pressure in a high pressure tank becomes less than a first threshold pressure, the SOC of an energy storage device is increased to a margin SOC. When the gas pressure becomes a second threshold pressure which is lower than the first threshold pressure, the amount of fuel released from the high pressure tank is limited to prevent the occurrence of buckling, and limit the travel driving force by the motor to a required limit. At the time of limiting the travel driving force, electrical energy of the energy storage device is used to provide assistance in a manner that the travel driving force by the motor becomes the travel driving force of the required limit.

A method for determining membrane humidification by determining the membrane protonic resistance of a fuel cell stack at humidified conditions, and normalizing the base resistance of the fuel cell stack against the base resistance of a reference fuel cell stack.

A PEM fuel or electrolysis cell with an extended lifetime, improved performance and uniform and stable operation is disclosed wherein a membrane electrode assembly is provided with a gradient of one or more properties in combination with a modification of one or more control parameters of the cell during its operation.

A fuel cell apparatus may include a stack, a stack air blower configured to supply external air to the stack, a humidifier configured to extract moisture contained in exhaust air and to supply the extracted moisture to external air supplied to the stack, a first bypass channel configured to allow exhaust air to bypass the humidifier, a first three-way valve controlled to adjust the amount of exhaust air that bypasses the humidifier, and a humidity sensor configured to sense the humidity of external air. The fuel cell apparatus may also include a second bypass channel configured to allow external air to bypass the humidifier, a second three-way valve controlled to adjust the amount of external air that bypasses the humidifier, and a controller configured to control the first three-way valve and the second three-way valve depending on the sensed humidity value of the external air.

A method comprising feeding a fuel and an oxidant to individual cells in a fuel cell stack, each having two electrode layers and an electrolyte layer arranged between the electrode layers. The method further includes compressing the cell stack with a clamping device, and detecting a compression pressure upon the cell stack with at least one pressure sensor. The method also includes determining a moisture content of the two electrolyte layers based on the detected compression pressure.