A fuel cell is operated with high power such that which a humidified gas and a dry gas are selectively supplied as oxidant to a cathode of the fuel cell. This method includes (S1) supplying a humidified gas while a power is constantly maintained or until the power begins to decrease; (S2) after supplying the humidified gas, supplying a dry gas to obtain a greater power than an average power of the step (S1); and (S3) after obtaining a predetermined power in the step (S2), repeatedly supplying a humidified gas in case the power decreases and supplying a dry gas in case the power decreases again afterwards, thereby increasing the power such that the predetermined power is maintained. This method provides an optimal operating condition to a fuel cell, thereby ensuring a high power.

A fuel cell apparatus (10) and method (50) of operating a fuel cell are provided. The fuel cell apparatus (10) includes a fuel cell assembly (12) having a first outlet (26) and a first vessel (34) coupled to the first outlet (26) and forming a first dead end. The first vessel (34) is arranged to receive and hold a portion of a first reactant and water when a supply of the first reactant is being fed to the fuel cell assembly (12) and to return the first reactant in the first vessel (34) to the fuel cell assembly (12) via the first outlet (26) when the supply of the first reactant to the fuel cell assembly (12) is cut off.

Disclosed is a method for dynamic variable humidity control; wherein the flow rate of the working gas flow is changed repeatedly according to a certain time interval and increment.

The present invention provides a relative humidity and condensed water estimator for a fuel cell and a method for controlling condensed water drain using the same. Here, the relative humidity and condensed water estimator is utilized in control of the fuel cell system involving control of anode condensed water drain by outputting at least two of signals comprising air-side relative humidity, hydrogen-side relative humidity, air-side instantaneous or cumulative condensed water, hydrogen-side instantaneous or cumulative condensed water, instantaneous and cumulative condensed water of the humidifier, membrane water contents, catalyst layer oxygen partial pressure, catalyst layer hydrogen partial pressure, stack or cell voltage, air-side catalyst layer relative humidity, hydrogen-side catalyst layer relative humidity, oxygen supercharging ratio, hydrogen supercharging ratio, residual water in a stack, and residual water in a humidifier.

A fuel cell control method includes detecting a state value indicating a state in a fuel cell during an operation of the fuel cell. The fuel cell includes a membrane electrode assembly and a separator stacked on the membrane electrode assembly. The membrane electrode assembly includes a solid polymer electrolyte membrane sandwiched between an anode electrode and a cathode electrode. It is determined whether a liquid connects the solid polymer electrolyte membrane and the separator based on the state value detected. The fuel cell is dried in a case where it is determined that the liquid connects the solid polymer electrolyte membrane and the separator.

Various embodiments of the present disclosure are directed to methods and systems for determining at least one actual value of a controlled variable of a conditioning unit for a reactant of a fuel cell. In one example embodiment, the method steps for determining the at least one actual value of a controlled variable includes: measuring a measured value of the actual value of the at least one controlled variable, calculating a model value of the at least one controlled variable using a model of the conditioning unit, calculating a model value of the actual value of the at least one controlled variable using a sensor model, calculating a correction value for the at least one controlled variable, and calculating the actual value of the at least one controlled variable as the sum of the correction value and of the model value of the at least one controlled variable.

A rechargeable battery assembly for a vehicle has a housing and at least one metal-air rechargeable battery arranged in the housing. A filter device is arranged in the housing and conditions the inlet air of the at least one metal-air rechargeable battery such that the inlet air exhibits a predetermined air humidity.

A flow deflecting device is provided that deflects the inlet air in the housing such that the filter device can be regenerated by waste heat of the at least one metal-air rechargeable battery.

A rechargeable battery assembly for a vehicle has a metal-air rechargeable battery and a filter device to condition inlet air supplied to the metal-air rechargeable battery such that the inlet air exhibits predetermined inlet air values. The filter device has one or more filter elements, one or more sensor devices that determine at least one inlet air parameter, and one or more valve devices. A control system is coupled to the sensor devices so as to receive sensor signals for the at least one inlet air parameter and is coupled to the valve devices. The control system adjusts, depending on the received sensor signals, the valve devices in order to control the predetermined inlet air value in that the inlet air is guided through the filter elements; is guided past the filter elements; or is guided to an air outlet for regenerating the filter elements.

An evaporative cooling type fuel cell system and a cooling control method for the same are provided. The fuel cell system includes a stack that generates electric power by reacting hydrogen as fuel with air as an oxidant. The method includes adjusting an operation pressure of the stack based on a current operation temperature of the stack and adjusting the amount of water supplied to the stack from a water reservoir based on the current operation temperature. The water is supplied to a cathode of the stack. Thus, a compact-simplified fuel cell system is provided, thereby reducing manufacturing costs and weight.

A fuel cell system that includes a fuel cell body that is formed by a membrane electrode assembly including an anode catalyst and a cathode catalyst between which an electrolyte membrane is sandwiched and a pair of separators forming an anode-catalyst-side flow channel and a cathode-catalyst-side flow channel, a fuel supply system configured to supply fuel gas to the fuel cell body, an oxidant supply system configured to supply oxidant gas to the fuel cell body, a control device that controls these supply systems in accordance with an operating state of the fuel cell system and a catalyst deterioration recovery device that recovers deterioration of the anode catalyst. The catalyst deterioration recovery device includes a plurality of catalyst deterioration recovery means, a specific operating state detecting means configured to detect a specific operating state of the fuel cell system and a selecting means configured to selectively activate the plurality of catalyst deterioration recovery means in accordance with the specific operating state.