Abstract: A method for controlling a fuel cell system is a method for controlling a fuel cell system including a solid oxide fuel cell which generates a power upon receiving supplies of an anode gas and a cathode gas. The method for controlling the fuel cell system includes; as a stop control of the fuel cell, stopping a supply of the anode gas while continuing a supply of the cathode gas to the fuel cell, and shutting off a discharge side of an anode of the fuel cell; and carrying out an additional control to supply the anode gas to the fuel cell during the stop control and/or an additional control to decrease the flow rate of the cathode gas during the stop control.

Abstract: A fuel cell system that has a fuel cell stack is provided. The system includes an electrolyte membrane, and a cathode and an anode that are a pair of electrodes disposed on opposite sides of the electrolyte membrane. A controller applies voltages to the cathode and the anode of the fuel cell stack before hydrogen that operates the fuel cell stack is supplied to the anode. When the voltages are applied to the cathode and the anode, hydrogen that resides in the cathode flows to the anode through the electrolyte membrane to decrease the concentration of the hydrogen in the cathode. The fuel cell system reduces the concentration of hydrogen discharged to the outside of the vehicle by reducing the concentration of hydrogen in the cathode before driving of the fuel cell is initiated.

Abstract: A fuel cell system comprises a fuel cell; a reactive gas supply mechanism configured to supply a reactive gas to the fuel cell; a discharge flow path configured to discharge an off-gas and water discharged from the fuel cell; a valve provided in the discharge flow path; a remaining water purging controller configured to control a remaining water purging process of the fuel cell by using the reactive gas supply mechanism and the valve; a heating portion configured to heat the valve; and a failure detector configured to detect a failure of the heating portion. When a failure of the heating portion is detected, the remaining water purging controller performs the remaining water purging process and increases a water discharge power in the remaining water purging process than a water discharge power in the remaining water purging process performed when no failure of the heating portion is detected.

Abstract: An electrical contact device for the diversion of electrical current from a fuel cell stack can have a plurality of electrically conductive contact regions which are delineated from each other. A plurality of electrically conductive first contact structures connects each, or a plurality of, the contact region(s) to an external load current circuit. Via at least one switching element arranged in a first contact structure, an electrically conductive connection may be disconnected by the first contact structure, in particular between at least one contact region and a load current circuit. In this way it is possible to adjust the overall resistance of the contact structure, and thus the Joule heat produced in the contact regions. Second contact structures that are arranged between the contact regions enable a further increased variability of the overall electrical resistance of the contact device.

Abstract: A method of shutting down operation of a fuel cell vehicle includes: blocking, by a controller, an air supply to a fuel cell stack when an operation shutting down command of the fuel cell vehicle is applied; increasing, by the controller, a voltage at an rear end of a stack main relay connected to the fuel cell stack; and opening, by the controller, the stack main relay when the voltage at the rear end of the stack main relay is higher than a stack voltage by a predetermined voltage or more.

Abstract: A power source system may include a main power source, a power converter including a capacitor, a relay configured to switch between connection and disconnection between the power converter and the main power source, an auxiliary power source, a boost converter having a low voltage terminal thereof connected to the auxiliary power source, and having a high voltage terminal thereof connected to the power converter without interposing the relay, and a controller configured to pre-charge the capacitor prior to placing the relay in a connected state when a main switch of a vehicle is turned on. The controller may be configured to store a peak value of a current of the auxiliary power source in a memory of the controller, and start to pre-charge the capacitor when a current of the auxiliary power source falls from the peak value by more than a predetermined current difference.

Abstract: A method for identifying a driving pattern for fuel economy improvement of a hybrid vehicle is provided. The method includes allocating priorities in accordance with influences exerted on fuel economy based on a heating load and an electric load. A current driving pattern is then selected in the order of a high heating load driving pattern, a high electric load driving pattern, an aggressive driving pattern, a high speed driving pattern, and a city driving pattern.

Abstract: A separator for a fuel cell includes a channel having a passage that is a flow path of a reaction gas, a manifold part formed at a peripheral of the channel and communicating with the passage such that the reaction gas is introduced into and discharged from the channel, and a connector connecting the channel and the manifold part such that the reaction gas flows between the channel and the manifold part. The manifold part includes an inlet manifold through which the reaction gas is introduced into the channel and formed at a lower portion of the channel, and an outlet manifold configured to discharge the reaction gas from the channel to an outside of the fuel cell and formed at an upper portion of the channel.

Abstract: A sensor node of a sensing network acquires first sensing data from an internal sensing node and/or second sensing data via an interface from an external sensing node. The sensor node is configured with a selected configuration file. The first and second events are detected as a function of the first and/or second sensing data based on the configuration file. The method further includes performing a first action set of the plurality of action sets as a function of detecting the first event and performing a second action set of the plurality of action sets as a function of detecting the second event, wherein the first and second action sets are defined by the configuration file. Once configured with the configuration file, detecting the first and second events and performance of any of the first and second action sets is performed autonomously of a controller or host of a system being monitored by the sensing network.

Abstract: An electrical power supply system has a fuel cell module and a battery. The fuel cell can be selectively connected to the battery system through a diode. The system preferably also has a current sensor and a controller adapted to close a contactor in a by-pass circuit around the diode after sensing a current flowing from the fuel cell through the diode. The system may also have a resistor and a contactor in another by-pass circuit around the diode. In a start-up method, a first contactor is closed to connect the fuel cell in parallel with the battery through the diode and one or more reactant pumps for the fuel cell are turned on. A current sensor is monitored for a signal indicating current flow through the diode. After a current is indicated, a by-pass circuit is provided around the diode.

Abstract: A method is disclosed for regenerating an electrode of a flow battery. The method can be executed during shutdown of the flow battery from an active charge/discharge mode to an inactive, shut-down mode in which neither a negative electrolyte nor a positive electrolyte are circulated through at least one cell of the flow battery. The method includes driving voltage of the least one cell of the flow battery toward zero by converting, in-situ, the negative electrolyte in the at least one cell to a higher oxidation state. The negative electrolyte is in contact with an electrode of the at least one cell. The higher oxidation state negative electrolyte is used to regenerate, in-situ, catalytically active surfaces of the electrode of the at least one cell.

Abstract: A redox flow battery system includes pumps, a pump control unit, an SQC measuring unit, and a terminal-voltage measuring unit. The pump control unit includes a reference-flow-rate acquiring unit which acquires a reference flow rate of the pumps corresponding to the state of charge of electrolytes; a terminal-voltage determination unit which determines whether or not a terminal voltage of a battery cell reaches the lower limit or the ripper limit of a predetermined voltage range; and a pump-flow-rate setting unit which sets the reference flow rate for the pumps in the case where the terminal voltage does not reach the upper or lower limit of the predetermined voltage range, and sets a flow rate obtained by adding a predetermined flow rate to the reference flow rate for the pumps in the ease where the terminal voltage reaches the upper or lower limit of the predetermined voltage range.

Abstract: A control unit of a fuel cell system includes a valve control unit configured such that, when it is determined that an exhaust valve is stuck open in a quick warming-up operation, the valve control unit sets at least one of an operable opening area which is an opening area capable of being changed by control and a rate of opening change which is an opening changeable frequency at which an opening is changeable per unit time, for at least one of a pressure adjusting valve and a flow division valve, such that a flow rate of a cathode gas supplied to a fuel cell is in an allowable range of a requested supply flow rate required for the quick warming-up operation.

Abstract: A fuel pressure regulator unit is mounted on a manifold. The fuel pressure regulator unit includes a housing providing a fuel inlet passage, a regulated fuel outlet passage, a sense pressure passage, a recycle passage and a mixed fuel passage. A pressure regulator is provided in the housing and is arranged fluidly between the fuel inlet passage and the regulated fuel outlet passage. The sense passage fluidly interconnects the mixed fuel passage and the pressure regulator. The pressure regulator is configured to regulate the flow of fuel from the fuel inlet passage to regulated fuel passage in response to a pressure from the sense pressure passage. An ejector is arranged within the housing and fluidly between the regulated fuel outlet passage and the mixed fuel passage. An ejector is configured to receive recycled fuel from the recycle passage.

Abstract: A constant voltage control method for a fuel cell vehicle includes: determining whether vehicle state information satisfies a cold start condition when the fuel cell vehicle is started; starting constant voltage control on a fuel cell when the vehicle state information satisfies the cold start condition; comparing an RPM of an air blower for supplying air to the fuel cell with a predetermined stop control condition; and terminating the constant voltage control on the fuel cell when the RPM of the air blower satisfies the predetermined control-stopping condition.

Abstract: A system for controlling low-temperature starting of a fuel cell vehicle includes a high-pressure hydrogen flow control valve controlling a flow of hydrogen supplied to a fuel cell stack. A fuel cell controller is configured to change and control an opening rate of the high-pressure hydrogen flow control valve when an internal temperature of the fuel cell stack is a reference value or less. When the opening rate of the high-pressure hydrogen flow control valve decreases, a pressure of the hydrogen passing through the high-pressure hydrogen flow control valve decreases to increase a temperature of the hydrogen which is supplied to the fuel stack.

Abstract: A coolant bypass structure includes a main loop forming a channel in which coolant circulates; a bypass loop connected to the main loop and forming a selective bypass channel; and a stack bypass valve provided between the main loop and the bypass loop to open and close the bypass loop according to a predetermined temperature, and provided with an outlet temperature sensor. The coolant bypass structure may improve marketability by decreasing the starting time of the fuel cell vehicle in a frozen state and improve power efficiency.

Abstract: A fuel cell system employs a fuel cell stack having an air electrode, an electrolyte membrane, and a fuel electrode. The fuel cell system includes an air residual space, from which air supplied to the air electrode is not discharged to stay behind therein when the fuel cell system is stopped. The air residual space communicates with the air electrode. The fuel cell system includes a hydrogen residual space, from which hydrogen supplied to the fuel electrode is not discharged to stay behind therein when the fuel cell system is stopped. The hydrogen residual space communicates with the fuel electrode. A residual ratio satisfies a specific reference range and corresponds to a ratio of the molecular number of hydrogen that stays behind in the hydrogen residual space to the molecular number of oxygen in air that stays behind in the air residual space when the fuel cell system is stopped.

Abstract: A method of activating a catalyst for a fuel cell in order to perform catalyst activation in a cathode electrode of the fuel cell includes a first process in which hydrogen is supplied into an anode electrode, the side of an air supply line of the cathode electrode is sealed, and the side of an air exhaust line of the cathode electrode is opened to an atmosphere, a second process in which the side of the air exhaust line of the cathode electrode is sealed after the first process, and a third process in which catalyst activation is performed in the cathode electrode after the second process.

Abstract: A fuel cell system includes: a fuel cell stack; a voltage sensor configured to detect voltage of the fuel cell stack; a fuel cell relay connected to the fuel cell stack; a switch connected between the fuel cell stack and the fuel cell relay; an overcurrent detector configured to detect an overcurrent flowing to the switch; and a power generation stop device configured to stop power generation of the fuel cell stack when the overcurrent detector detects the overcurrent and the detected voltage becomes a specified value or less.

Abstract: A cooling arrangement for cooling a fuel cell in a fuel cell system is disclosed. The cooling arrangement has at least two fluidically connected cooling circuits in which a liquid coolant medium flows, The first cooling circuit includes a first coolant pump, a fuel cell heat exchanger, a heating unit, and a charge air cooler, which is in heat-exchanging contact with compressed supply air flowing to the fuel cell. The second cooling circuit includes a cooling heat exchanger for cooling the liquid coolant medium. The cooling arrangement includes at least one further coolant pump.

Abstract: The disclosure relates to a fuel cell stack and corresponding method of operating the fuel cell stack. The method comprises: determining a maximum allowable current that may be drawn from the fuel cell stack; repeatedly determining a magnitude of change to the prevailing maximum allowable current based on a prevailing allowable current ramp rate and an actual measured current of the fuel cell stack; updating the maximum allowable current according to the periodically determined magnitude of change; and controlling operating parameters of the fuel cell stack according to the prevailing maximum allowable current.

Abstract: A thermo-electro-chemical converter direct heat to electricity engine has a monolithic co-sintered ceramic structure or a monolithic fused polymer structure that contains a working fluid within a continuous closed flow loop. The co-sintered ceramic or fused polymer structure includes a conduit system containing a heat exchanger, a first high density electrochemical cell stack, and a second high density electrochemical cell stack.

Abstract: A fuel cell system includes a fuel cell stack having a plurality of cells each having hydrogen channels, a hydrogen channel inlet, and a hydrogen channel outlet, a load supplied with power from the fuel cell stack, a circulation passage connecting the channel inlet with the channel outlet, a hydrogen pump provided in the circulation passage, and a controller. The controller rotates the hydrogen pump in a positive direction so as to feed the hydrogen gas in a first amount into each cell through the channel inlet, at a flow rate larger than a minimum flow rate required for power generation, and then rotate the hydrogen pump in a negative direction so as to feed the hydrogen gas into each cell through the channel outlet, during a period from stop of power supply to the load, to the next start of power supply.

Abstract: A method of controlling the operation of a fuel cell system is provided. The method includes diagnosing a water shortage state in a fuel cell stack based on degradation of cooling performance and deterioration of the fuel cell stack and determining a diagnosis level of the fuel cell system based on the diagnosed water shortage state of the fuel cell stack. In addition, a regenerative operation is performed by selecting a regenerative operation mode which corresponds to the determined diagnosis level.

Abstract: An apparatus for removing moisture of a stack enclosure includes a protective case accommodating a fuel cell stack therein, a radiation heater mounted at a lower surface of the protective case, the radiation heater enabling discharged air to move toward an upper part of the protective case, and a cooler for cooling air moving along the upper part of the protective case, the cooler guiding cooled air to move toward the lower surface of the protective case.

Abstract: A vehicle includes a fuel cell having a stack for generating power and a controller. The controller is programmed to, in response to a fuel cell temperature decreasing to less than a temperature threshold after a shutdown, initiate a primary purge of the stack and terminate the primary purge at a predetermined anode pressure.

Abstract: A method of power generation for a solid alkaline fuel cell includes the step of exposing a cathode-side surface of the inorganic solid electrolyte to an atmosphere containing carbon dioxide of greater than or equal to 600 ppm and less than or equal to 20000 ppm.

Abstract: A fuel cell system comprises: a fuel cell; a cooling liquid supply flow path for supplying cooling liquid to the fuel cell; a radiator for cooling the cooling liquid; a first temperature sensor, provided at an outlet of the radiator, for measuring a temperature of the cooling liquid; an ambient temperature sensor; and a controller. The controller executes: estimating a temperature of the cooling liquid inside the cooling liquid supply flow path based on an ambient temperature measured by the ambient temperature sensor; acquiring a temperature of the cooling liquid inside the cooling liquid supply flow path based on the temperature measured by the first temperature sensor after it is determined that the cooling liquid within the radiator has reached the first temperature sensor; and adjusting a flow rate of the cooling liquid based on the estimated temperature or the acquired temperature of the cooling liquid.

Abstract: A fuel cell assembly includes a fuel cell arrangement having first and second plates sandwiching a membrane electrode assembly. The arrangement defines first and second header regions that each include supply and return headers. The first plate defines coolant channels that extend between the header regions and connect to the return header in the first region. The second plate defines coolant channels that extend between the header regions and connect to the supply header in the first region.

Abstract: Disclosed are fuel cell architectures, thermal sub-systems, and control logic for regulating fuel cell stack temperature. A method is disclosed for regulating the temperature of a fuel cell stack. The method includes determining a pre-start temperature of the fuel cell stack, and determining, for this pre-start temperature, a target heating rate to heat the stack to a calibrated minimum operating temperature. The method then determines a hydrogen bleed percentage for the target heating rate, and executes a stack heating operation including activating the fuel cell stack and commanding a fluid control device to direct hydrogen to the cathode side at the hydrogen bleed percentage to generate waste heat. After a calibrated period of time, the method determines if an operating temperature of the stack exceeds the calibrated minimum stack operating temperature. Responsive to the operating temperature being at or above the minimum operating temperature, the stack heating operation is terminated.

Abstract: A fuel cell stack, a method of operating a fuel cell stack and a fuel cell system. In one particular form, shutting down the stack upon detection of a leakage of fuel either within the stack or from the stack involves depressurizing and uniform consumption of hydrogen by catalytic consumption in the cathode of all cells. Upon consumption of oxygen in the cathode portion of the stack by chemical reaction, the remaining unreacted nitrogen from the air acts as an inerting fluid. After an indication of reaction cessation is established, at least some of the inerting fluid is conveyed from the cathode portion to the anode portion. One or more of a bleed valve, backpressure valve and bypass valve are manipulated to promote the anode portion depressurization, cathode portion inerting and subsequent conveyance of the inerting fluid to the stack anode portion.

Abstract: There is provided a fuel cell system comprising a controller configured to control an opening position of a valve element of a flow dividing valve. The valve element is configured to be movable between a first position and a second position, according to the number of steps of a stepping motor that is provided to drive the valve element. When causing a fuel cell to perform power generation, the controller moves the valve element by a first number of steps such as to move from the first position to the second position and to additionally move the valve element toward the second position, based on a second number of steps that are taken from a time when the valve element starts moving from the first position toward the second position to a time when a voltage measured by a voltage sensor exceeds a predetermined value.

Abstract: The operation control method of a fuel cell includes acquiring a startup temperature of the fuel cell; acquiring a present temperature of the fuel cell; setting a present target operation point of the fuel cell that is identified by an output voltage value and an output current value based on the startup temperature, or based on the startup temperature and the present temperature; controlling at least one of the flow of the reaction gas supplied to the fuel cell, and an output voltage of the fuel cell so that the operation point of the fuel cell becomes the target operation point, and setting the target operation point includes a process of setting an operation point having a low output voltage value as the target operation point when the startup temperature is low as compared to the case when the startup temperature is high, if the present temperature is the same.

Abstract: A charging device is configured to deliver power to a portable, power-consuming device, having a profile sensor which can detect information relating to the identity of power-consuming device to which the charging device is connected and may also have a communication channel configured to transmit said information to a remote server. In use, data can be collected or aggregated relating to power-consuming devices by connecting the charging device to the portable power-consuming device; sensing, by a profile sensor in the charging device, information relating to the identity of the power-consuming device; and transmitting the information to a remote server over a communication channel. Collected data may, for example, be used to identify when fuel for a charging device may need replenishment.

Abstract: A power generator and method include passing ambient air via an ambient air path past a cathode side of the fuel cell to a water exchanger, picking up water from the cathode side of the fuel cell and exhausting air and nitrogen to ambient, passing hydrogen via a recirculating hydrogen path past an anode side the fuel cell to the water exchanger, where the water exchanger transfers water from the ambient air path comprising a cathode stream to the recirculating hydrogen path comprising an anode stream, and passing the water to a hydrogen generator to add hydrogen to the recirculating hydrogen path and passing the hydrogen via the recirculating hydrogen path past the anode side of the fuel cell.

Abstract: An airflow control method of an air control system for a fuel cell stack (FCS) includes opening a recirculation valve by a controller to recirculate air through a compressor to increase a temperature of the air prior to entering the FCS to offset a FCS temperature below a predetermined threshold in response to identification to a cold-start event. The recirculation valve may be arranged with the compressor to recirculate air therethrough. The FCS may be arranged with the compressor and recirculation valve to selectively receive air therefrom. A sensor may measure thermal conditions of the FCS. The controller may be programmed to receive signals from the sensor indicating thermal conditions of the FCS, and to operate the recirculation valve based on the signals to recirculate air through the compressor to increase a temperature of the air prior to entering the FCS.

Abstract: A fuel cell system comprising: a supply valve for supplying the anode gas into an anode system of the fuel cell system; a purge valve for discharging an off-gas from the anode system; a pressure detecting portion that estimates or measures a pressure inside the anode system; and a hydrogen concentration estimating portion that estimates a hydrogen concentration inside the anode system based on a pressure decrease during a purge valve open duration in a supply valve close state.

Abstract: A control method for fuel cell system capable of executing an idle stop operation is provided, in which operation power generation of a fuel cell is selectively stopped according to a required output of a load and cathode gas is intermittently supplied to the fuel cell during an operation stop. An upper limit value and a lower limit value of an output voltage of the fuel cell during the idle stop operation is set, the cathode gas is intermittently supplied with the output voltage of the fuel cell set at a value between the upper limit value and the lower limit value, a wet/dry state of the fuel cell is detected, a wet/dry appropriate range in which the wet/dry state of the fuel cell during the idle stop operation is appropriate is set, and it is determined whether or not the detected wet/dry state of the fuel cell is within the set wet/dry appropriate range.

Abstract: A method for recovering performance of a degraded polymer electrolyte fuel cell stack through electrode reversal. In detail, oxide films formed on the surface of platinum of a cathode is removed through an electrode reversal process that creates a potential difference between an anode and the cathode by supplying air to the anode instead of hydrogen and supplying a fuel to the cathode instead of air, thus rapidly recovering the performance of a degraded polymer electrolyte fuel cell stack.

Abstract: A fuel cell of a fuel cell stack includes a power generation reaction area, a marginal area around the power generation reaction area, and a first reactant gas flow area and a second reactant gas flow area. The first reactant gas flow area and the second reactant gas flow area are provided outside the power generation reaction area and inside the marginal area. The fuel cell stack includes a first load applying unit configured to apply a first load to the marginal area in the stacking direction and a second load applying area configured to apply a second load to the power generation reaction area in the stacking direction.

Abstract: A fuel cell system includes a control unit configured to perform air-conditioning-system preparation control, wherein, under the air-conditioning-system preparation control, when an air conditioning system is not requested to heat air, it is determined whether or not a coolant within a coolant circulation passage is capable of being supplied to an air conditioning circuit, when the coolant within the coolant circulation passage is not capable of being supplied to the air conditioning circuit, the heater is operated to maintain a first predetermined temperature or higher of the coolant within the air conditioning circuit, and when the coolant within the coolant circulation passage is capable of being supplied to the air conditioning circuit, the air-conditioning water pump is operated to draw the coolant from the coolant circulation passage into the air conditioning circuit and to maintain the first predetermined temperature or higher of the coolant within the air conditioning circuit.

Abstract: A flow control valve 26 can adjust the percentage of the flow rate of cooling water to a radiator 23 to a predetermined value (50%) or smaller. When the temperature of the cooling water in a fuel cell 11 is determined to be a predetermined temperature (0° C.) or higher after the cooling water is supplied to the fuel cell 11 with the percentage of the flow rate of the cooling water to the radiator 23 set to the predetermined value (50%) or larger, a controller 41 performs a predetermined percentage supply operation for controlling the flow control valve 26 and a pump 22 to supply the cooling water to the fuel cell 11 with the percentage of the flow rate of the cooling water to the radiator 23 set to the predetermined value (50%) or larger.

Abstract: Methods and systems are provided for cold-start of fuel cell stack in fuel cell vehicles. In one example, a method may include in response to cold-start of fuel cell vehicle, limiting the load drawn from the fuel cell stack. In addition, a coolant pump may be operated at a higher rate through a bypass loop to get heat quickly to the fuel cell stack to increase the solubility of water in the fuel cell stack to prevent ice formation. The net effect is that the fuel cell stack is then operated within the ice capacity of the membrane, and start-up at lower temperatures is possible without experiencing an intermittent performance drop due to active area freezing. Once the fuel cell stack is sufficiently warmed up, the coolant pump rate and fuel cell stack may be adjusted according to the demand.

Abstract: A fuel cell system. The fuel cell system includes at least one fuel cell having an anode chamber and a cathode chamber separated from the anode chamber, and a cathode gas source, a gas supply line connected to the cathode gas source, for feeding cathode gas into the cathode chamber, and an exhaust air line connected to the cathode chamber for the conducting exhaust air out of the cathode chamber. The gas supply line and the exhaust air line are connected by at least one gas flow regulation element, which opens the gas supply line in the direction of the exhaust air line and/or the exhaust air line in the direction of the gas supply line in dependence on an operating status of the fuel cell.

Abstract: A flat plate type solid oxide fuel cell stack module is obtained by stacking a plurality of flat plate type solid oxide fuel cell stack units. Each of the cell stack unit comprises an anode plate, a cell unit and a cathode plate. The anode plate has a first flow channel, four corner first fuel input holes and a central first fuel output hole. The cathode plate has a second flow channel, a plurality of lateral second air input grooves and a plurality of lateral second air output grooves. The cell unit includes an anode layer, a cathode plate, four corner third fuel input holes and a central third fuel output hole. An anode mental net and an anode sealing material are disposed between the anode plate and the cell unit, a cathode mental net and a cathode sealing material are disposed between the cathode plate and the cell unit.

Abstract: An anode-cathode supply device for a fuel cell of a fuel cell system, including an anode supply system and a cathode supply system, which may be brought into a fluid communication with each other with the aid of an overflow line situated therebetween and through an overflow valve, the overflow valve being designed as an NC overflow valve, the NC overflow valve being closed in a de-energized state of the NC overflow valve and at a balanced pressure ratio at the NC overflow valve is provided. A method for supplying an operating medium or a device for supplying an operating medium, in particular hydrogen, from an anode to a cathode of a fuel cell of a fuel cell system, preferably a vehicle, in particular an electric vehicle, chronologically during and/or after the fuel cell is deactivated is also provided. A fuel cell system for a vehicle, in particular an electric vehicle, or to a vehicle, in particular an electric vehicle is also provided.

Abstract: A system and method of controlling a performance of a fuel cell stack is provided. In particular, the output performance of the fuel cell stack is determined by comparing the difference between an initial voltage and a voltage after a predetermined time lapses with the difference between the initial voltage and a preset minimum voltage.

Abstract: A power net system of a fuel cell vehicle is provided. The power net system includes a fuel cell and a high-voltage battery unit connected in parallel via a main bus and a first switching unit that is configured to form and block an electrical connection between an output terminal of the fuel cell and the main bus. A load device diverges and is connected between the output terminal of the fuel cell and the first switching unit. A reverse current blocking unit is connected between the first switching unit and a node from which the load device diverges. A second switching unit is configured to form and block an electrical connection between the output terminal of the fuel cell and the load device. A controller operates the first and second switching units and adjusts the electrical connection state between the main bus and the high-voltage battery unit.

Abstract: Improved methods are disclosed for shutting down and storing a fuel cell system, particularly for below freezing temperature conditions. The methods comprise stopping power production from the fuel cell stack, monitoring the amount of energy remaining in an energy supply, monitoring the stack temperature, and repeatedly performing a predetermined warming operation if the stack temperature falls to a normal threshold temperature and if the amount of energy remaining exceeds a certain minimum amount. In the improved methods, when the amount of remaining energy is less than or equal to the minimum amount, a final warming operation is performed that differs from the predetermined warming operation.