Abstract: Apparatus, methods, and systems for estimating hydrogen concentration and/or pressure in an anode compartment of a fuel cell stack in a fuel cell vehicle. In some implementations, the estimates are based on a correlation between a transient dip in voltage in response to an anode to cathode bleed event and a concentration of hydrogen in the anode compartment of a fuel cell stack. Some implementations may comprise initiating a bleed event, sensing a transient dip in voltage in response to the bleed event, and using the correlation to calculate an estimate of a concentration and/or pressure of the gas in the anode compartment. The sensitivity of the correlation and hence the accuracy of estimation may change with the power level and may be accounted for in the correlation.

Abstract: The invention relates to a device for controlling the voltage of a cell of a fuel cell, characterized in that said control device comprises a first transistor (Q1) associated with the cell, which is connected to the cell via the base thereof and to a current generator, and a control voltage source (VRi) inserted between the cell and the first associated transistor (Q1), the control voltage source supplying a control voltage equal to the voltage differential between the first and second threshold voltages, such that: when the cell has a voltage (V1) higher than a first threshold voltage, the first transistor (Q1) has a voltage (Vbe1), at the terminals of the base-emitter junction thereof, which is higher than the second threshold voltage, and which conducts the current, and, when the cell has a voltage (V1) which is lower than the first threshold voltage, the first transistor (Q1) has a voltage (Vbe1), at the terminals of the base-emitter junction thereof, which is lower than the second threshold voltage and w

Abstract: A control device of a fuel cell system sets a required output of a fuel cell stack that is required according to a present power demand and predicts the required output and the current according to the temperature of the fuel cell stack from a predetermined output state map that is preset. The control device sets an operation state quantity according to the predicted current and the temperature of the fuel cell stack from a predetermined operation state quantity map that is preset. The control device includes at least one of a pressure at an air supply port of air that is supplied to the cathode electrode of the fuel cell stack, a utilization rate of the air at the cathode electrode, a flow rate of a cooling medium that cools the fuel cell stack, and humidity of the air at the air supply port as the operation state quantity.

Abstract: A fuel cell system includes a hydrogen path for supplying odorant-added hydrogen to the fuel cell, an estimating unit to estimate the depositing of the odorant in the fuel cell, and control unit to heat the fuel cell up to a temperature at which at least part of the odorant deposited in the fuel cell evaporates when the depositing of the odorant is estimated.

Abstract: Disclosed is method of operating a fuel cell which can output an electrical maximum power dependent on the operating temperature for a given fuel gas flow, and which exhibits aging in dependence on the operating duration which brings about an increase of the electrical internal resistance with progressive operating duration. In the disclosed method, the starting value (T0) of the operating temperature for a new fuel cell or for a new fuel cell stack is typically smaller than or equal to the operating temperature, at which the electrical maximum power is achieved and the fuel cell or the fuel cell stack is regulated such that the decrease of the output electrical power as a consequence of aging is partly or completely compensated in that the operating temperature (T) of the fuel cell or of the fuel cell stack is increased with progressive aging.

Abstract: The present invention provides a hybrid fuel cell system that is configured to determine if an idle stop condition has been satisfied during a normal operation mode of the hybrid fuel cell system, cut off air supply to a fuel cell to stop power generation of the fuel cell and reduce a voltage which the fuel cell outputs in response to determining that the idle stop condition has been satisfied. The voltage of a bidirectional converter, connected between a battery and a bus terminal is reduced and the output of the fuel cell is controlled, based on a first predetermined value and maintained at that first predetermined value. Subsequently, the battery is charged via the output current of the fuel cell generated by maintaining the reduced voltage of the bidirectional converter.

Abstract: A fuel cell system includes; a fuel cell which generates electricity by using a fuel gas and an oxidant gas as reaction gases; current control means which controls current of a fuel cell; voltage control means which controls voltage of the fuel cell; and heat value control means which calculates a heat value required by the fuel cell system and decides a target current value of the current control means and a target voltage value of the voltage control means so as to generate the calculated necessary heat amount, thereby controlling the heat value. Thus, it is possible to supply a heat required for the fuel cell system without increasing the size of the fuel cell system.

Abstract: The disclosure is directed at a method and apparatus for controlling fuel cell operating characteristics. In certain situations, the operating efficiency of fuel cells is degraded to external conditions. Providing a method and apparatus to control operating conditions for the fuel cell assists in improving the operating efficiency. This can be achieved by controlling certain environmental conditions, such as temperature and relatively humidity, in the area surrounding the fuel cell.

Abstract: A fuel cell system for generating a hydrogen test pulse includes a fuel cell stack having an anode inlet in fluid communication with a hydrogen source via a fuel spending line, a cathode inlet in fluid communication with an oxidant source, and an anode outlet and a cathode outlet in fluid communication with an exhaust line. An electric pressure regulator is in fluid communication with the fuel spending line. An overpressure valve is in fluid communication with an overpressure line, which is in fluid communication with the fuel spending line between the electric pressure regulator and the fuel cell stack. A hydrogen sensor is in communication with the exhaust line, and is configured to measure the hydrogen test pulse.

Abstract: A fuel cell system that is able to perform power generation more stably than in the past regardless of external environment is provided. Based on a temperature of a power generation section detected by a temperature detection section, a supply amount of a liquid fuel from a fuel pump is adjusted, and therefore control in which the temperature of the power generation section becomes constant is performed. In addition, a fuel cell system that is able to perform power generation in a vaporization supply type fuel cell more stably than in the past is provided. A level of a power generation voltage supplied from the power generation section is raised by a boost circuit. In a control section, operation of the boost circuit is controlled using a given control table, and therefore control is performed on an output voltage and an output current supplied from the boost circuit to a load.

Abstract: The present disclosure relates to systems and methods that may be used to predict a performance metric of a fuel cell. A system consistent with the present disclosure may include sensors in communication with the fuel cell stack, a performance metric prediction system, and a control system. The performance metric prediction system may determine a current density based on inputs provided by the sensors at a plurality of time periods, calculate a first parameter while the current density is below a lower threshold, and calculate a second parameter while the current density is above an upper threshold. The first parameter and the second parameter may be used to selectively adjust a fuel cell polarization curve over time. Based upon the polarization curve, a performance metric of the fuel cell stack may be predicted. The control system may implement a control action based upon the performance metric.

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: A flow battery system includes a flow cell, a reservoir including an aqueous electrolyte, a memory in which command instructions are stored, a model of the flow cell stored within the memory, and a processor configured to execute the command instructions to obtain a current signal and a voltage signal, estimate a state of charge (SOC) of the flow cell using the obtained current signal, compute a model voltage of the flow cell using the obtained current signal, the obtained voltage signal, and the model, compare the model voltage with the obtained voltage signal, calculate a voltage error based upon the comparison of the model voltage with the obtained voltage signal, and correct the estimated SOC based upon the voltage error.

Abstract: 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.

Abstract: To provide a solid oxide fuel cell system capable of efficiently and simply controlling a low speed fuel cell module and a high speed inverter. The invention is a solid oxide fuel cell system, comprising: a fuel cell module, a fuel flow regulator unit, a control section comprising a first power demand detection circuit for controlling the fuel supply amount and for setting the value of current extractable from the fuel cell module; an inverter for extracting current from fuel cell module; and a second power demand detection circuit; and having an inverter control section for controlling the inverter independently from the fuel cell controller so that a current responsive to power demand is extracted from the fuel cell module in a range not exceeding the extractable current value input from the fuel cell controller.

Abstract: The present invention is a solid oxide fuel cell system for generating variable power in response to power demand, having: a fuel cell module; a fuel supply device; a power demand detection device; a controller for controlling the amount of fuel supplied by the fuel supply device based on the power demand, and for setting an extractable current value, being the maximum extractable current value; an inverter for extracting current from the fuel cell module within a range not exceeding the extractable current value; and an extractable current detection device for detecting actual extracted current extracted from the fuel cell module; whereby if certain increase-limiting condition is matched, then even when power demand is rising, the controller maintains the extractable current value at a certain value, or lowers the extractable current value, and does not increase that extractable current value.

Abstract: The invention is a solid oxide fuel cell system including: a fuel cell module, a fuel flow regulator unit, a first power demand detection device, a control section for controlling a fuel supply amount and setting the current value extractable from the fuel cell module, an inverter for extracting current in a range not exceeding the extractable current value, and a power state detecting sensor for detecting actual extracted current value; whereby if actual extracted current value declines, then under circumstances where power demand begins to rise in a state of extra margin in the fuel supply amount after the controller suddenly decreases the extractable current value and suddenly reduces the electrical collector, the controller increases the extractable current value at a high current rise rate of change.

Abstract: In a fuel cell system, when an electric current drawn from fuel cells is controlled based on a target power generation value, an upper limit of the electric current is optimally set to make suspensions of operation caused by voltage drops to be as infrequent as possible. The upper limit of the electric current is set by adding a predetermined offset value (e.g., 2 A) to an average value of the electric current before a predetermined delay time (e.g., 10 seconds). Moreover, when the electric current drawn from the fuel cells is controlled based on a target power generation value, the value of the electric current is compared with the upper limit of the electric current, to control the electric current.

Abstract: An apparatus and method to detect a short circuit event in a fuel cell system of a vehicle. The detection relies on three existing sensors within the fuel cell system, two current sensors and a voltage sensor. A controller executes an algorithm with a set of thresholds stored in a computer readable medium to monitor the sensors to sense if any of the threshold values are crossed. If crossed, the controller may take remedial action to stop the short circuit and/or prevent damage to the fuel cell system. A mode manager may work with the controller to determine when the operating conditions of the fuel cell system are ideal for sensing for a low voltage condition indicative of a short circuit event. A pair of integrators may be electrically coupled to an alternating current sensor to differentiate a short circuit event from a high frequency resistance current.

Abstract: A battery emulation device for simulating a battery cell voltage at a terminal of a battery control unit in accordance with a setpoint value includes a control unit configured to determine the setpoint value and provide the determined setpoint value via a galvanically isolated interface; and at least one emulation channel, each including: a voltage source; an amplifier unit; connection lines for connecting the emulation channel; measurement lines; and a fault simulation device configured to simulate fault states.

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: According to a first aspect, the present invention relates to a method of controlling a fuel cell, comprising a step of controlling the fuel cell electric efficiency per unit of active surface area by checking and/or adjusting the current density produced in the fuel cell per unit of active surface area. According to another aspect, the present invention concerns a fuel cell suitable for obtaining an electric power output, which comprises, among the other things, control means of the electric efficiency of the fuel cell including means suitable for checking and/or adjusting the current density produced in the fuel cell per unit of active surface area.

Abstract: A diagnostic and heat management system for a fuel cell stack is provided herein that includes a diagnostic control analyzer that diagnoses and analyzes a state of the fuel cell stack by measuring a voltage and a current of the fuel cell stack. Also, an AC signal generator generates a diagnostic AC signal, and an AC component driving element that is included in an AC component in a current of the fuel cell stack. Additionally, a termoelement is driven as a heat absorbing device when a temperature of the AC component driving element is equal to or greater than a predetermined temperature and is driven as a heat emitting device when a temperature of the AC component driving element is less than a predetermined temperature, in order to manage heat generation in the AC component driving element.

Abstract: A fuel cell system including: a fuel cell assembly; a fuel feed conduit; a gas feed conduit; an anode exhaust. The anode exhaust conduit is in fluid communication with the fuel feed conduit and at least a portion of a fluid in the anode exhaust conduit is recycled to the fuel feed conduit. The fuel cell system may include a temperature measurement device for determining a fuel cell temperature and/or a current measurement device for determining a fuel cell current. A first control can be configured to control a flow rate of the fluid in the anode exhaust conduit which is recycled into the fuel feed conduit in response to the fuel cell temperature. A second control can be configured to control a flow rate of a fluid in the gas feed conduit in response to the fuel cell current.

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: A failure diagnosis apparatus that includes an alternating current (AC) absorption unit that is connected to the fuel cell stack and switched based on an applied AC signal to enable a current from the fuel cell stack to flow. In addition, an AC signal generator is configured to generate the AC signal and supply the generated AC signal to the AC absorption unit. As the current from the fuel cell stack is absorbed by the AC absorption unit based on an alternating signal, a stack current input into a diagnosis processing unit includes an AC component, thus the diagnosis processing unit may diagnose fuel cell stack failure by analyzing a frequency of the AC component.

Abstract: A fuel cell system includes a fuel cell stack which includes a plurality of fuel cells contacted in series by a plurality of interconnects. The various embodiments provide systems and methods for coupling a fuel cell stack with an electric bypass module within a hot zone. The bypass module may include elements for conducting a current between interconnects in a fuel cell stack and thereby bypass a failed fuel cell that has become a resistive parasitic load.

Abstract: A hydrogen generator of the present invention includes a reformer (16) for generating a hydrogen-containing gas through a reforming reaction using a raw material; a combustor (102a) for heating the reformer (16); a combustion air supplier (117) for supplying combustion air to the combustor (102a); and an abnormality detector (110a) for detecting an abnormality; and a controller (110) configured to control the combustion air supplier (117) such that the reformer (16) is cooled with a higher rate in an abnormal shut-down process executed after the abnormality detector (110a) detects the abnormality, than in a normal shut-down process.

Abstract: A system for optimizing the purge cycle of a fuel cell stack responsive to the performance of the fuel cell. The system includes a controller that measures a process parameter indicative of the rate at which water is being produced in the fuel cell. If the measured value exceeds a threshold value, then the purge assembly is automatically actuated.

Abstract: Provided is a fuel cell system which can measure an air blow interval and consider an exceptional condition such as a high-potential-avoiding operation, thereby enabling an accurate judgment of degradation of an electrolyte. An actual air blow time interval is measured while estimating a theoretical air blow time interval when an increase of a hydrogen consumption amount corresponding to a cell voltage in the high-potential-avoiding operation according to an output current by using a relationship table which contains a record of a relationship between a hydrogen consumption amount consumed for maintaining the function of a fuel cell and the air supply time interval varying with the increase of the hydrogen consumption amount. The degradation of the electrolyte of the fuel cell is judged according to whether the measured actual air blow time interval is shorter than the theoretical air blow time interval corresponding to the hydrogen consumption amount.

Abstract: A casing of a fuel cell system is divided into a fluid supply section, a module section, and an electrical equipment section. A detector, a fuel gas supply apparatus, an oxygen-containing gas supply apparatus, and a water supply apparatus are provided in the fluid supply section. A fuel cell module and a combustor are provided in the module section. A power converter and a control device are provided in the electrical equipment section. The module section is interposed between the fluid supply section and the electrical equipment section.

Abstract: A direct alcohol fuel cell system including a fuel cell unit having a direct alcohol fuel cell including an anode electrode, an electrolyte membrane, and a cathode electrode in this order, a fuel supply unit for supplying alcohol fuel to the anode electrode, a detecting unit for detecting a current value I of a current flowing between the anode electrode and the cathode electrode of the direct alcohol fuel cell or an output voltage value V of the direct alcohol fuel cell, and a temperature T of the direct alcohol fuel cell, and a control unit for determining a supply quantity Q of alcohol fuel to the anode electrode based on detection results of the current value I or the output voltage value V, and the temperature T and controlling the fuel supply unit so that the supply quantity of the alcohol fuel is adjusted to the supply quantity Q.

Abstract: A method for providing a current density set-point for a fuel cell stack in response to a power request from the stack where the set-point is determined based on system parameters that identify the life and degradation of the stack. The method includes dividing a current density range of the fuel cell stack into a predetermined number of sample regions, and selecting the sample regions in order from low to high during the current set-point analysis. The method calculates an average cell voltage for the current density of the selected sample region, and stack power from the average cell voltage. The method then determines whether a power request signal is less than the stack power for the selected sample region and greater than the calculated power for the previous sample region, and if so, calculates the current density set-point at the requested power based on these values.

Abstract: There is provided a fuel cell power generation system in which power loss in a power line electrically connecting a stack and a power conversion circuit, thereby attaining high power generation efficiency. A reformer and the stack are disposed in a main body package. Stack output terminals 31 are provided in both ends in a stacking direction of the stack. A power conversion circuit is disposed in the main body package and arranged in the proximity to the stack. Power conversion circuit input terminals are provided on the power conversion circuit and arrayed in a direction parallel to the stacking direction of the stack. Stack output lines electrically connect the stack output terminals and the power conversion circuit input terminals.

Abstract: A fuel cell system can be initiated in shorter time while minimizing the deterioration of a fuel cell. The fuel cell system includes a fuel cell stack having a fuel electrode, an oxidizer electrode and an electrolyte membrane disposed there between, the fuel cell producing electricity by an electrochemical reaction of a fuel gas and an oxidizer gas, which are supplied to the fuel electrode and the oxidizer electrode, respectively; a fuel gas supplying device for supplying the fuel gas to the fuel cell stack; an oxidizer gas supplying device for supplying the oxidizer gas to the fuel cell stack; a current controlling device for extracting a current from the fuel cell stack; and a voltage sensor disposed in at least two of the fuel cell stacks.

Abstract: Systems and methods to control the delivery of coolant to a coolant loop within a vehicular fuel cell system. During periods of low power output from one or more fuel cell stacks, operation of a pump used to circulate coolant through the loop is intermittent, thereby reducing pump usage during such times. The frequency of pump operation, as measured by a pump on/off (i.e., pulsed) cycle, may be adjusted to keep a local temperature rise within the one or more stacks to no more than a small amount over the bulk stack temperature.

Abstract: A fuel cell system includes a fuel cell, an exhaust mechanism that is connected to a downstream end of an anode gas flow channel and is capable of selecting an exhaust mode and a closed mode, a detecting device for detecting a downstream flow of an impurity in the anode gas flow channel, and a controlling device for controlling the operation of the exhaust mechanism such that the exhaust mode is selected when the magnitude of the downstream flow of the impurity meets a predetermined switching criterion and the closed mode is selected when the magnitude of the downstream flow of the impurity does not meet the switching criterion.

Abstract: Even if a failure occurs in a bypass valve during low-efficiency power generation, the occurrence of an excessive stoichiometry ratio in a fuel cell can be prevented. An output from a pressure sensor or a current sensor is monitored by a control device, and when a failure associated with a closed-valve malfunction of the bypass valve occurs, the degree of opening of the pressure regulating valve is increased to increase an amount of cathode-off gas exhaust, and a revolution speed of an air compressor is reduced to an amount of air discharged by the air compressor, thereby preventing an excessive stoichiometry ratio in the fuel cell.

Abstract: A fuel cell and method for manufacturing the fuel cell are described herein. Basically, the fuel cell is formed from an electrode/electrolyte structure including an array of anode electrodes and cathode electrodes disposed on opposing sides of an electrolyte sheet, the anode and cathode electrodes being electrically connected in series, parallel, or a combination thereof by electrical conductors that traverse via holes in the electrolyte sheet. Several different embodiments of electrical conductors which have a specific composition and/or a specific geometry are described herein.

Abstract: A fuel cell system for a vehicle includes a fuel cell arrangement that is coupleable to a vehicle drive as a primary load, and to a plurality of secondary loads. A control apparatus which controls the primary load and the secondary loads includes a monitoring circuit that is operable in a special operating mode of the fuel cell system, with the secondary loads being switched on and/or off as a manipulated variable in order to maintain the output voltage, as a reference variable, at a low voltage value that is formed by a cell voltage of the fuel cells of less than 0.45 V on average.

Abstract: A method of operating a capacitive deionization cell using a regeneration cycle to increase pure flow rate and efficiency of the cell.

Abstract: A fuel cell fleet has a plurality of fuel cell systems each connected to a data server. The data server may be configured to obtain operational data from of the plurality of fuel cell systems. An efficiency controller operably connected to the data server and is configured to predict an efficiency and a power output of the fleet from the operational data and optimize the efficiency of the fleet to minimize the fleet fuel consumption while maintaining a desired fleet output power. The efficiency may be determined by a ratio of the fleet output current or output power to the fleet fuel consumption.

Abstract: A system and method for detecting an intermittent failure of an injector that injects hydrogen gas fuel into the anode side of a fuel cell stack in a fuel cell system. The method includes operating the injector at a fixed injector pulse width and frequency, which causes the stack to generate a constant current, and therefore, a constant fuel consumption rate. While at a constant current, the injector is commanded to a constant duty cycle and frequency that matches the rate of fuel consumption in the fuel cell system. The resulting fuel pressure feedback is then monitored, and if it diverges from a defined nominal value, either in a constant or oscillatory manner, it can be determined that the injector has an intermittent opening failure. In one embodiment, the determination of the injector failure is performed during a shut-down sequence of the fuel cell system.

Abstract: Provided are an apparatus and a method for managing a fuel cell vehicle system, and more particularly, an apparatus and a method for managing a fuel cell vehicle system capable of optimally maintaining a driving method based on environmental information and product information.

Abstract: Provided are an apparatus and a method for managing a stationary fuel cell system, and more particularly, an apparatus and a method for managing a stationary fuel cell system capable of optimally maintaining a driving method based on environmental information and product information.

Abstract: A system and method for preventing anode reactant starvation. The system includes a hydrogen source, an anode bleed valve, and a cell voltage monitor. The system also includes an anode sub-system pressure sensor and a controller configured to control the anode sub-system. The controller determines the average cell voltage and estimates the hydrogen molar fraction and/or nitrogen molar fraction in the anode sub-system. The controller also receives measurement data from the cell voltage monitor and the pressure sensor, and determines whether there is a decrease in the minimum cell voltage in response to changes in the anode pressure. If the controller detects a decrease in the minimum cell voltage in response to changes in the anode pressure, the controller corrects for the decrease by increasing anode pressure and/or by decreasing the molar fraction of nitrogen in the anode sub-system.

Abstract: There is provided a fuel cell power generation system in which power loss in a power line electrically connecting a stack and a power conversion circuit, thereby attaining high power generation efficiency. A reformer and the stack are disposed in a main body package. Stack output terminals 31 are provided in both ends in a stacking direction of the stack. A power conversion circuit is disposed in the main body package and arranged in the proximity to the stack. Power conversion circuit input terminals are provided on the power conversion circuit and arrayed in a direction parallel to the stacking direction of the stack. Stack output lines electrically connect the stack output terminals and the power conversion circuit input terminals.

Abstract: The invention relates to a cooling system for a fuel cell, comprising a main heat-transfer-fluid circuit including a circulation pump (6) and a heat exchanger (8) with the exterior, which feed an upstream pipe (12) supplying the fluid to the cells (4) of the fuel cell, said fluid leaving the cells via a downstream pipe (14) in order to return to the main pump. The invention is characterised in that the main circuit comprises a three-port controlled valve (10, 16) on each upstream (12) and downstream (14) pipe, the third available port (10c) of the upstream pipe (12) being connected to the inlet of the pump (6) and the third available port (16c) of the downstream pipe (14) being connected to the outlet of the pump in order to establish a secondary fluid circuit.

Abstract: Disclosed is a fuel cell system which includes a fuel cell having an anode and a cathode and for producing electricity through reaction between the fuel gas and the oxidant gas, a fuel gas supply path through which the fuel gas passes, an oxidant gas supply path through which the oxidant gas passes, a voltage sensing device for detecting voltage produced by the fuel cell during power generation, and a decision device for determining whether or not cross leakage occurs between the anode and the cathode of the fuel cell, based on voltage information sent from the voltage sensing device. Moreover, the decision device determines that the cross leakage occurs between the anode and the cathode, if the voltage produced by the fuel cell is less than a predetermined value during the power generation.

Abstract: An FC voltage increasing converter includes a plurality of converter parts having reactors. Regarding the first of the plurality of converter parts provided with a thermistor, the output starts to be limited when the temperature detected by the thermistor reaches a limitation starting temperature, which is obtained based on a reference heat-resistant temperature, which is obtained by subtracting an error of the thermistor from a specification heat-resistant temperature of each of the reactors. Meanwhile, regarding the second, third and fourth of the plurality of converter parts not provided with thermistors, the outputs start to be limited when the temperature detected by the thermistor reaches a limitation starting temperature obtained based on an allowable temperature, which is obtained by subtracting a characteristic-variation temperature of the reactor from the reference heat-resistant temperature of the reactor.