Abstract: An IR resistance of each of unit cells is measured, and a highest unit cell voltage as a threshold voltage is set based on the IR resistance and load current. The setting of the highest unit cell voltage uses map data that approximates current-voltage characteristics of a unit cell when the fuel gas is insufficiently supplied. In that case, the highest unit cell voltage is determined based on the voltage with respect to the load current obtained from the map data, and the IR loss calculated from the IR resistance and the load current. This highest unit cell voltage is compared with the measured unit cell voltage. If the unit cell voltage is below the highest unit cell voltage, the power generation of the fuel cell is stopped or restrained.

Abstract: In one or more embodiments, a fuel cell system includes a fuel cell stack including an anode and a cathode, a first conduit positioned to supply oxygen to the cathode, a second conduit positioned to supply hydrogen to the anode, and a third conduit positioned separate from the first and second conduits and to supply oxygen to the second conduit. The third conduit may be positioned to supply oxygen from the first conduit to the second conduit.

Abstract: Purge valves that are manually turned ON but are automatically or electrically turned OFF as the fuel cell's production of electricity reaches a predetermined level, e.g., steady state or thereabout are disclosed. The purge valve may be opened at system start-up, or may be opened at system shut-down so that the purge valve is armed and the fuel cell system is purged at the next start-up. Also disclosed is an integrated fluidic interface module that contains various fluidic components including one of these purge valves. The integrated fluidic interface module can operate passively or without being actively controlled by a processor. Methods of operating a fuel cell system, wherein the fuel cell system is purged at system start-up, are also disclosed. The purging automatically stops when the anode plenum is fully purged and replaced with fuel.

Abstract: A device and method for ensuring proper fuel cell system warmup or shutdown during freeze conditions. A three-way valve is used in conjunction with a flow-controlling orifice to ensure that the orifice avoids ice blockage during frozen conditions. Dry, warm air is delivered as a slip stream under pressure to a cathode flowpath, where the construction of the orifice is such that it is structurally compliant to promote flexing in response to the pressurized slip stream, thereby helping to break up any small amount of ice that may have formed in or on the orifice.

Abstract: An apparatus for heating a fuel cell stack in a cold start mode is provided. The apparatus comprises a fuel cell stack, a boost converter, and a controller. The fuel cell stack powers a vehicle. The boost converter includes a power switch that is thermally coupled to the fuel cell stack. The controller is configured to receive a signal indicative of a temperature during a vehicle startup and to compare the temperature to a predetermined temperature value. The controller is further configured to activate the power switch if the temperature is below the predetermined temperature value such that the power switch generates heat to apply to the fuel cell stack and generates a voltage for powering a power circuit to enable the vehicle to driveaway while the fuel cell stack receives the heat.

Abstract: Methods of operating a fuel cell system, wherein the fuel cell system is purged at system start-up, are disclosed. The purging automatically stops when the anode plenum is fully purged and replaced with fuel. Also discussed are purge valves that are manually turned ON but are automatically turned OFF as the fuel cell's production of electricity reaches a predetermined level, e.g., steady state or thereabout. The purge valve may be opened at system start-up, or may be opened at system shut-down so that the purge valve is armed and the fuel cell system is purged at the next start-up. Also disclosed is integrated fluidic interface module that contains various fluidic components including one of these purge valves. The integrated fluidic interface module can operate passively or without being actively controlled.

Abstract: A fuel cell power plant includes a cell stack assembly having an anode and a cathode. A component is arranged in fluid connection with at least one of the anode and cathode. The component has a first shut-down cooling rate. A heat exchanger is arranged in fluid communication with and between the component and one of the anode and cathode. The heat exchanger has a second shut-down cooling rate greater than the first shut-down cooling rate. Water vapor within the fuel cell power plant outside of the cell stack assembly will condense and freeze in the heat exchanger rather than the component, avoiding malfunction of the component upon start-up in below freezing environments.

Abstract: A method for starting a cold or frozen fuel cell stack as efficiently and quickly as possible in a vehicle application is based upon a state of charge of a first power source such as a high voltage battery. Power flow between the first power source and fuel cell system is coordinated in conjunction with a specific load schedule and parallel control algorithms to minimize the start time required and optimize system warm-up.

Abstract: An object of the present invention is to provide a fuel cell system capable of avoiding damage to a circulation pump at a low temperature to improve system efficiency. The fuel cell system of the present invention includes a fuel gas circulation system having a circulation path which re-circulates, through a fuel cell, a fuel off gas discharged from the fuel cell, and a circulation pump which feeds under pressure the fuel off gas in the circulation path; and a controller which controls driving of the circulation pump. The controller stops the driving of the circulation pump at a predetermined low temperature.

Abstract: A fuel cell system includes a fuel cell module having a solid-oxide fuel cell and a reformer adapted to perform steam reforming of a fuel gas supplied to the solid-oxide fuel cell, a water supplying unit and a control unit. The controller unit is adapted to control, at least during start up of the fuel cell system switching of a pulse pump from a stop state to a pumping state to start pumping of water, and to change the pulse pump to a normal control state after performing a start-operation-control which sets a feed flow rate of the pulse pump higher for a predetermined time than a feed flow rate of the water during the normal control state.

Abstract: A fuel cell system that employs a technique for reducing or significantly eliminating the MEA degradation that occurs as a result of the hydrogen-air front in the anode flow channels at system start-up. After system shut-down, any hydrogen remaining within the anode flow channels will be quickly reacted or diffused. At the next start-up, a switch is closed to provide a dead short across the positive and negative terminals of the fuel cell stack as hydrogen is being introduced into the anode flow channels. The existing air in the cathode flow channels reacts with the hydrogen being introduced across the membrane in the normal fuel cell reaction. However, the short prevents a voltage potential across the membrane.

Abstract: An arrangement for high temperature fuel cell system for substantially reducing the amount of purge gas in an emergency shut-down situation. The arrangement includes a known volume for containing a pneumatic actuation pressure, the known volume including at least one discharge route for designed discharge rate, at least one pressure source providing pressure capable of performing the pneumatic actuation, at least one purge gas source having a gas overpressure capable of displacing residual reactants in the fuel cell system. Purge gas is discharged through the discharge route causing pressure decline in the known volume, accomplishing a designed time delay in state change of at least one pneumatically actuated valve, to reduce or close down completely emergency shutdown actuated flow of the purge gas into the fuel cell system piping after the designed time delay.

Abstract: A fuel cell system of the present invention includes: a fuel cell (1) supplied with fuel gas and oxidizing gas to generate electricity; a fuel gas supply unit supplying the fuel gas to the fuel cell (1); an oxidizing gas supply unit supplying the oxidizing gas to the fuel cell (1); an aftercooler (7) cooling the oxidizing gas supplied to the fuel cell (1) by heat exchange with a coolant; an oxidizing gas temperature detector (16, 17) detecting temperature of the oxidizing gas; and a coolant circulation controller (21a) starting circulation of the coolant when the detected temperature of the oxidizing gas exceeds a predetermined value. The predetermined value is set to a value of not higher than a minimum electricity generation temperature of the fuel cell (1), and a circulation timing and flow rate of the coolant for the aftercooler (7) are controlled such that the supplied oxidizing gas does not become cold. This enables the fuel cell (1) to generate electricity at cold start-up.

Abstract: A fuel cell system includes a control valve for controlling the pressure of anode gas to be supplied to a fuel cell, a buffer unit for storing anode off-gas discharged from the fuel cell, and a start-up anode gas pressure control unit for feeding inert gas in an anode gas flow passage of the fuel cell under pressure to the buffer unit by controlling the pressure of the anode gas to be supplied to the fuel cell when the fuel cell system is started. The start-up anode gas pressure control unit controls the pressure of the anode gas according to a temperature difference between the temperature of the fuel cell and that of the buffer unit.

Abstract: A fuel cell system comprising a generation chamber, a plurality of fuel cells arranged in the generation chamber, fuel gas feeding means for feeding a fuel gas to the fuel cells, oxygen-containing gas feeding means for feeding an oxygen-containing gas to the fuel cells, power converter means for converting the DC output of the fuel cells into an alternating current, power control means for controlling the electric power output to the power converter means from the fuel cells, and generation control means for controlling the flow rate of the fuel gas fed to the fuel cells and the flow rate of the oxygen-containing gas fed to the fuel cells. A fuel gas buffer amount specific to the fuel cells is not smaller than a fuel gas amount that is needed within a maximum period of increase-needing time that is necessary until the flow rate of the fuel gas increases to a required amount when the amount of increase in the flow rate of the fuel gas is set to be a maximum.

Abstract: Deterioration of an electrolyte and a sealing member is suppressed taking account of the durable temperature characteristics thereof, while enhancing the starting performance of a fuel cell. For this realization, in a system comprising a gas piping system for supplying a reactant gas to a fuel cell, and a gas supply controller for altering the supply state of the reactant gas in response to a power generation request, a gas supply quantity is altered in accordance with the temperature of the fuel cell. Preferably, the gas supply quantity is altered in accordance with the durable temperature characteristics of a passage member forming a gas passage of the reactant gas. Furthermore, the differential pressure of the gas supply state between the anode side and the cathode side of the fuel cell is preferably taken into account and the differential pressure between both poles is suppressed by altering the gas supply quantity on the cathode side as the case may be.

Abstract: A fuel cell system for a vehicle includes a fuel cell, a fuel supply device, an oxidizer supply device, an anode potential measuring device, and a discharge controller. The anode potential measuring device is configured to measure an anode potential of an anode. The discharge controller is configured to control discharge of electric current from the fuel cell as part of a process of stopping the fuel cell during idling of the vehicle. When receiving idle stop permission for the fuel cell, the discharge controller determines whether the fuel cell is permitted to discharge. When the anode potential is equal to or lower than a predetermined threshold value, the discharge controller permits the fuel cell to discharge. When the anode potential is higher than the predetermined threshold value, the discharge controller does not permit the fuel cell to discharge.

Abstract: The method for storing a fuel cell comprises a first calibration phase of a reference membrane by nuclear magnetic resonance to obtain a progression curve of the maximum water load of the fuel cell membrane versus the temperature of the membrane, and a second calibration phase of a standard reference cell to obtain a relationship between the electrical resistance of the standard reference cell, the water load of its membrane and its temperature. The method then comprises a drying phase dependent on the two calibration phases.

Abstract: A fuel cell system includes a fuel cell, a secondary cell, a voltage transformer, and a control portion. The control portion charges the secondary cell with surplus electric power at the time of starting the fuel cell, and adjusts voltage of the fuel cell between an open-circuit voltage and a high-potential-avoiding voltage in the case where the secondary cell is expected to become overcharged while the output voltage of the fuel cell is decreased from the open-circuit voltage to the high-potential-avoiding voltage. The foregoing case is at least one of the case where a passage electric power that passes through the voltage transformer exceeds a secondary cell-charging-purpose permitted-to-pass electric power, the case where the input electric power restriction value for the secondary cell is exceeded, and the case where amount of regeneration by the mover that is charged is not restricted.

Abstract: A system includes a radiator side flow path for supplying a coolant which has cooled a fuel cell stack to a radiator, a bypass flow path for allowing the coolant which has cooled the fuel cell stack to bypass the radiator, a thermostat valve for increasing a flow rate of the coolant flowing through the radiator side flow path in a case where the temperature of the coolant is high as compared to a case where the temperature of the coolant is low, and an electric heater for warming up the coolant. The electric heater is controlled based on an outside atmospheric pressure and on the temperature of the coolant such that the temperature of the coolant flowing into the fuel cell stack is raised in a case where the outside atmospheric pressure is high as compared to a case where the outside atmospheric pressure is low.

Abstract: A fuel cell system comprises an oxygen removing device having an inlet fluidly connected to at least one of the reactant gas source and an outlet of the cathode gas flow field, and an outlet fluidly connected to each of an anode control valve and a cathode control valve. Various fuel cell operation processes are also disclosed.

Abstract: A fuel cell system of the present invention includes a fuel cell, a supply channel which supplies, to the fuel cell, a fuel gas supplied from a fuel supply source, a variable gas supply device which adjusts a gas state on an upstream side of this supply channel to supply the gas to a downstream side, a control section which performs PI control of a gas supply command amount with respect to the variable gas supply device, and an abnormality judgment section to judge whether or not the variable gas supply device is abnormal. The controller uses, as a part of a correction term of the PI control, a learning term constituted by integrating an I term only in a case where an operation state of the fuel cell satisfies predetermined learning allowable conditions. The abnormality judgment section judges based on this learning term whether or not the variable gas supply device is abnormal.

Abstract: Provided is a fuel cell system capable of making a shift of an operation state while optically controlling an output voltage and an output voltage of a fuel cell. When an ECU judges that the time when an operation should be shifted from a low-efficiency operation to a normal operation has come, the ECU performs, as preprocessing prior to a shift to a ?V control, processing of increasing an oxidant gas supplied to a fuel cell stack by a predetermined amount. After this processing, the ECU detects output power, calculates an output power deviation, and then compares the output power deviation with a set deviation threshold. When the output power deviation exceeds the deviation threshold, the ECU carries out the ?V control, and then carries out an I-V control. Meanwhile, when the output power deviation does not exceed the deviation threshold, the ECU judges that the time when the ?V control is carried out has not come yet, and automatically starts the I-V control without carrying out the ?V control.

Abstract: A fuel cell system includes a fuel cell stack for receiving a supplied reactant gas to generate a power; an air compressor for removing moisture remaining in the fuel cell stack during the stop of the power generation; a secondary cell for supplying an operative power to the air compressor; and a controller for controlling the balance of water flowing into and out of the fuel cell stack so that a time required to remove the moisture remaining in the fuel cell stack by the air compressor is substantially constant.

Abstract: Provided is a method of starting a fuel cell system including a hydrogen concentration acquisition process of acquiring a concentration of hydrogen in the anode, a threshold value determination process of determining whether or not the concentration of hydrogen which is acquired by the hydrogen concentration acquisition process is greater than or equal to a predetermined second threshold value, and a starting pressure setting process of setting a pressure of hydrogen supplied to an anode from a hydrogen tank when supplying hydrogen to the anode from the hydrogen tank in a state in which a contactor is shut off.

Abstract: Provided is a method of controlling a fuel cell system including a stop command sensing process of sensing a stop command output when the fuel cell system stops, an anode pressure increasing process of increasing pressure so that the pressure of the anode reaches a first predetermined pressure value, and a stop-time discharge process of performing discharge by consuming oxygen remaining within an oxidant off-gas while driving an oxidant off-gas circulation pump.

Abstract: A manifold for use with fuel cell and fuel cell stacks is provided. In certain examples, the manifold may be constructed and arranged to provide air to all cathodes in a first fuel cell stack fluidically coupled to the manifold and configured to provide fuel to all anodes in the first fuel cell stack. In some examples, the manifold may be constructed and arranged to provide air to all cathodes in a first fuel cell stack and a second fuel cell stack and to provide fuel to all anodes in the first fuel cell stack and the second fuel cell stack.

Abstract: Provided is a method for shutting down an indirect internal reforming SOFC, in which reliable reforming, prevention of anode oxidative degradation, fuel saving and time saving are possible. Reforming catalyst layer temperature T is measured, and FkCALC is calculated; when FkCALC?FkE, T is measured, and FkCALC and FkMinCALC are calculated; if FkMinCALC?FkE, then the flow rate of the fuel supplied to the reformer is set to FkE and the method moves on to step D; if FkCALC?FkMinCALC<FkE, then C6 to C9 are performed in order; C6) the temperature of the reforming catalyst layer is increased; C7) T is measured, and FkCALC and FkMinCALC are calculated; C8) if FkCALC<FkE, then the flow rate of the fuel supplied to the reformer is set to FkMinCALC and the method returns to C6; C9) if FkCALC?FkE, then the flow rate of the fuel supplied to the reformer is set to FkE and the method moves on to D; D) the method waits for the anode temperature to fall below an oxidative degradation temperature.

Abstract: A fuel cell system and method that enables warm-up power generation corresponding to the residual water volume in the fuel cell stack without using auxiliary devices for measuring the residual water volume in the fuel cell stack. A controller computes total generated electrical energy Q by integrating of the generated current detected by current sensor during the period from start-up to shutting down of the fuel cell system, and stores the result in total generated electrical energy storage part. Also, controller measures fuel cell temperature Ts at the last shutting down cycle with temperature sensor, and stores it in power generation shutting down temperature storage part.

Abstract: A power generation characteristic estimation device for fuel cell includes a reference characteristic setting unit for setting a reference power generation characteristic of a fuel cell, a current detection unit for detecting an actual current of the fuel cell, a voltage detection unit for detecting an actual voltage of the fuel cell, and a characteristic estimation unit for estimating an actual power generation characteristic of the fuel cell based on a voltage difference between a voltage on the reference power generation characteristic and an actual voltage at the actual current. The characteristic estimation unit estimates the power generation characteristic during a warm-up operation of the fuel cell when a pressure of a gas supplied to the fuel cell is not lower than a predetermined value.

Abstract: A fuel cell system includes: a fuel cell activation portion that starts electricity generation of a fuel cell; a cooling medium passage that is provided with a pump and that is provided for passing a cooling medium through a cell-side passage for the cooling medium; and a pump control portion that stops the pump for a first predetermined period after a start of the electricity generation caused by the fuel cell activation portion at a time when a temperature of the fuel cell is a low temperature lower than or equal to a predetermined value, and that starts operating the pump after the first predetermined period elapses. The pump control portion includes a cooling medium reverse portion that alternately reverses a direction of flow of the cooling medium in the cell-side passage according to elapsed time by controlling operation of the pump after the first predetermined period elapses.

Abstract: A fluid supply system includes a fluid supply source, a first valve unit, a second valve unit, a first pressure detector, a second pressure detector, a third pressure detector, and a controller. If the pressure detected by the third pressure detector is less than a shutoff pressure at a timing of starting supply of fluid from the fluid supply source, the controller calculates a pressure equalization time from a timing at which opening of a pilot valve is completed to a timing at which a main valve starts closing, based on the pressures detected by the first pressure detector, the second pressure detector and the third pressure detector, sets a valve-open waiting time based on the pressure equalization time, and controls opening of the second valve unit upon elapse of the valve-open waiting time after controlling opening of the first valve unit.

Abstract: A portable fuel cell system includes a fuel cell having a plurality of flow inputs and a power output, a temperature sensor configured to measure operating temperature of the fuel cell, a power output sensor coupled to the fuel cell and configured to measure a power parameter related to fuel cell power output, a controllable power converter, coupled to the power output of the fuel cell, that transfers power from the fuel cell to the fuel cell system, and a flow control device coupled to a first flow input and configured to control a first one of the flow inputs into the fuel cell. The system further includes a fuel cell system controller, coupled to the fuel cell, the power output, the temperature sensor, the power output sensor, the controllable power converter, and the flow control device.

Abstract: A diagnostic system for determining whether a rotor shaft of a compressor is unbalanced. The compressor includes a displacement sensor that measures the displacement of the rotor shaft as it is rotating. The sensor dynamic frequency signal is sent to a bandpass filter that filters out an eigen-frequency frequency that is a function of shaft elasticity and rotor dynamics. The filtered frequency signal is then rectified by a rectifier to make the filtered frequency signal positive. The rectified signal is then passed through a low pass filter that converts the rectified signal to a DC signal. The DC signal is then sent to a controller that determines if the amplitude of the signal is above a predetermined threshold, which indicates a problem with the balance of the compressor.

Abstract: A fuel cell power generation system including a fuel cell, a fuel generator, an oxidizing gas supply device, an output controller, an open-close mechanism, and a controller. The controller is configured such that in a stop process, the controller controls the output controller to stop supplying the electric power to an external load; controls the oxidizing gas supply device to stop supplying an oxidizing gas and controls the open-close mechanism to close a passage upstream from an oxidizing gas channel; after the passage upstream from the oxidizing gas channel is closed, stops a raw material gas supply device and a water supply device when a predetermined period has elapsed, during which period a gas in the oxidizing gas channel is replaced by a fuel gas.

Abstract: A fuel cell system operating method in which a temperature of a fuel cell power generator is measured when the fuel cell power generator stops generating power, and it is determined whether the temperature is within a predetermined temperature range, and a reverse current is supplied to the fuel cell power generator upon restart if the temperature was determined to be outside of the predetermined range so as to increase the efficiency of the system after restarting the fuel cell power generator after being exposed to extreme conditions. Subsequently, the reverse current supply to the fuel cell power generator stops and electric energy is generated through an electrochemical reaction between hydrogen and oxygen in the fuel cell power generator.

Abstract: A method that employs a model based approach to determine a maximum anode pressure set-point based on existing airflow in the exhaust gas line. This approach maximizes anode flow channel velocity during bleed events while meeting the hydrogen emission constraint, which in turn increases the amount of water purged from the anode flow channels to increase stack stability.

Abstract: Loss of flow battery electrode catalyst layers during self-discharge or charge reversal may be prevented by establishing and maintaining a negative electrolyte imbalance during at least parts of a flow battery's operation. Negative imbalance may be established and/or maintained actively, passively or both. Actively establishing a negative imbalance may involve detecting an imbalance that is less negative than a desired threshold, and processing one or both electrolytes until the imbalance reaches a desired negative level. Negative imbalance may be effectively established and maintained passively within a cell by constructing a cell with a negative electrode chamber that is larger than the cell's positive electrode chamber, thereby providing a larger quantity of negative electrolyte for reaction with positive electrolyte.

Abstract: A heating apparatus for a fuel cell that includes heating units that extend in the stacking direction of a plurality of separators, in contact with upper ends and lower ends of air intake sides of the stacked separators.

Abstract: The grill shutter is disposed between the front grill and the air intake duct. The grill shutter is capable of opening or closing shutter members and regulating positions of the shutter members when being opened. When a maximum supplied flow rate of air provided by the wind during running is greater than a flow rate of air required for the hydrogen fuel battery, the required flow rate of air is established only by opening/closing control of the shutter members through a grill shutter opening instruction. If this is not the case, the grill shutter members are opened fully through the grill shutter opening instruction to maximize the volume of the wind during running taken in from the front grille. Additionally, a shortfall in the required flow rate of air for the hydrogen fuel battery is compensated for by actuating the blower through a blower speed instruction.

Abstract: Deterioration at the start-up and deterioration during the leaving period are suppressed in a good balance. As a system shutdown process, a controller (30) causes consumption of the air (oxygen) present in an oxidant electrode of a fuel cell stack (1) (oxygen consumption control). Further, after the termination of the oxygen consumption control, the controller (30) performs control to set a medium pressure hydrogen valve (13) and a hydrogen pressure adjustment valve (14) in a closed state. The controller (30) thereby causes hydrogen to be held in a passage located between the medium pressure hydrogen valve (13) and the hydrogen pressure adjustment valve (14). During a system shutdown period, a predetermined amount of hydrogen (medium pressure hydrogen) held in the hydrogen supply passage (L1) at a position between the medium pressure hydrogen valve (13) and the hydrogen pressure adjustment valve (14) can be supplied to the fuel electrode of the fuel cell stack (1) through a bypass passage (L2).

Abstract: A fuel cell system includes a reformer that generates reformed gas using reforming fuel; a fuel cell that generates electric power using the reformed gas generated by the reformer; and a control device. The control device includes a plurality of different stop control modes for stopping operation of the fuel cell system, and selects a specific stop control mode among the plurality of stop control modes, according to the cause of a malfunction of the fuel cell system.

Abstract: A fuel cell system includes a fuel cell; a fuel gas supplying unit supplying the fuel gas into the fuel cell on the anode side thereof; an oxidizing agent gas supplying unit supplying the oxidizing agent gas into the fuel cell on the cathode side thereof; a raw material gas supplying unit supplying the raw material gas into the fuel cell; and a controlling unit controlling the supply of the fuel gas, the oxidizing agent gas and the raw material gas. After switching the output of electric power or the fuel cell off, the fuel gas supplying unit suspends the supply of the fuel gas, the oxidizing agent gas supplying unit suspends the supply of the oxidizing agent gas and the raw material gas supplying unit supplies the raw material gas into the fuel cell to purge the fuel cell on the cathode side.

Abstract: A fuel cell system includes a fuel cell, an operation controller and an air-conditioning mechanism. In response to a heating request for the air-conditioning mechanism during ordinary operation where the fuel cell is operated at an operating point on a current-voltage characteristic curve of the fuel cell, the operation controller compares a heat value-based required current value with an output-based required current value. When the output-based required current value is equal to or greater than the heat value-based required current value, the operation controller causes the fuel cell to be operated at an operating point on the current-voltage characteristic curve. When the output-based required current value is smaller than the heat value-based required current value, the operation controller controls the operating point of the fuel cell to an operating point of lower power generation efficiency than that of the operating point on the current-voltage characteristic curve.

Abstract: An electrochemical cell system is provided having: at least one electrochemical cell stack, each stack having at least one reactant fluid inlet; a pressure transmitter arranged in the at least one reactant fluid inlet of each stack; and a control unit for regulating the electrochemical cell system, the control unit receiving at least one signal value from the pressure transmitter indicative of the reactant fluid pressure. The control unit may compare the at least one signal value with a stored values and generate a leak indication based on the rate of pressure decay within the electrochemical cell system. A method of detecting and indicating a leak is also disclosed.

Abstract: An offset control arrangement is disclosed for controlling voltage values in a fuel cell system including an anode side, a cathode side and an electrolyte between the anode side and the cathode side. The fuel cell system can include at least one fuel cell array of at least two fuel cells, and at least one load for performing load function. The offset control arrangement can include voltage monitoring for monitoring an input voltage of the load, a control processor for processing the monitoring information, and at least one offsetting source in serial connection to the at least one fuel cell array, with a power level of the offsetting source being substantially low compared to the power level of the fuel cell array, and the offsetting source being arranged to perform at least unidirectional shifting of fuel cell array output voltage.

Abstract: A fuel cell system includes a reforming unit, a carbon monoxide decreasing unit, a fuel cell, a burner unit, a raw gas supply device, and a heating unit. The heating unit is controlled at a start-up operation of the fuel cell system, so as to adjust an amount of a desorbed raw gas desorbed out of components of the raw gas adsorbed to at least one of a reforming catalyst and a carbon monoxide decreasing catalyst such that a ratio of an amount of combustion air to an amount of a raw gas in the burner unit falls within a predetermined range.

Abstract: A system and method for controlling a fuel cell system start time based on various vehicle parameters. The method includes providing a plurality of inputs that identify operating conditions of the fuel cell system and determining a maximum allowable start-time of the fuel cell system using a hybridization control strategy and the plurality of inputs. The method then determines a maximum compressor speed and ramp rate to provide the optimal allowable start-time of the fuel cell system minimizing energy consumption and noise.

Abstract: An Anode Protection Systems for a SOFC system, having a Reductant Supply and safety subsystem, a SOFC anode protection subsystem, and a Post Combustion and slip stream control subsystem. The Reductant Supply and safety subsystem includes means for generating a reducing gas or vapor to prevent re-oxidation of the Ni in the anode layer during the course of shut down of the SOFC stack. The underlying ammonia or hydrogen based material used to generate a reducing gas or vapor to prevent the re-oxidation of the Ni can be in either a solid or liquid stored inside a portable container. The SOFC anode protection subsystem provides an internal pressure of 0.2 to 10 kPa to prevent air from entering into the SOFC system. The Post Combustion and slip stream control subsystem provides a catalyst converter configured to treat any residual reducing gas in the slip stream gas exiting from SOFC stack.

Abstract: A fuel cell system is disclosed with a fuel cell stack having a plurality of fuel cells, the fuel cell stack including an external electrical circuit adapted to control current from the fuel cell stack, a sensor for measuring at least one of an environmental condition affecting the fuel cell stack and a characteristic of the fuel cell stack, wherein the sensor generates a sensor signal representing a measurement of the sensor, and a processor for receiving the sensor signal, analyzing the sensor signal, and controlling an adaptive load applied to the external electrical circuit based upon the analysis of the sensor signal.