Abstract: A fuel-cell-system providing structure is provided which is capable of preventing a collision of a fuel cell with a related apparatus of the fuel cell while suppressing the increase in weight of a vehicle. A fuel cell system provided in a vehicle includes: a fuel cell unit in which a fuel cell is contained; and a related apparatus that is electrically connected to the fuel cell and that is located adjacent to the fuel cell unit. The related apparatus is arranged at a position closer to an outer surface of the vehicle than the fuel cell unit.

Abstract: When a power generation instruction value for a fuel cell is reduced during warm-up of the fuel cell by a low power generation efficiency operation as compared to a normal operation and when supply of a reactant gas to the fuel cell cannot be controlled so as to follow the reduction of the power generation instruction value, the reactant gas supply to the fuel cell is reduced and the output voltage to the fuel cell is increased. Thus, it is possible to charge an excessive power equivalent to a difference between a fuel cell generation amount and the power generation instruction value into a capacitance component of the fuel cell, so that the power supplied to the external load of the fuel cell coincides with the power generation instruction value. Thus, when a power request for the fuel cell during the low-efficiency operation is suddenly reduced, it is possible to perform control so that the excessive power is not supplied to the external load.

Abstract: A fuel cell system includes: a fuel cell stack which receives a fuel gas and an oxidation gas to generate a power; an air compressor which supplies the oxidation gas to the fuel cell stack; and a controller which reduces the oxidation gas flow rate supplied from the air compressor to the fuel cell stack in consideration of discharge from a capacitance component of the fuel cell stack when decreasing the output voltage of the fuel cell stack. When the output voltage of the fuel cell stack has dropped, the fuel cell system can control a cell operation in consideration of the discharge from the capacitance component of the fuel cell stack to an external load.

Abstract: There is disclosed a fuel cell system or the like capable of sufficiently reducing an exhaust hydrogen concentration even in a case where a fuel cell is operated in a state of a low power generation efficiency. A bypass valve B1 is arranged between an oxidation gas supply path 11 and a cathode-off gas channel 12. In a state in which supply of an oxidation gas to a cathode falls short, pumping hydrogen is included in a cathode-off gas. Therefore, a valve open degree of the bypass valve B1 is regulated, and a flow rate of bypass air is regulated to control the exhaust hydrogen concentration.

Abstract: A fuel cell system is equipped with a drive motor, a fuel cell, normal electric power generation means for performing normal electric power generation under a condition that the fuel cell is not warmed up, warm-up electric power generation means for performing warm-up electric power generation with lower electric power generation efficiency than normal electric power generation, and warm-up control means for controlling performance of warm-up electric power generation by the warm-up electric power generation means on a basis of a predetermined index on a necessity to warm up the fuel cell. The warm-up control means controls an operation state of the fuel cell during warm-up electric power generation on a basis of a correlation between the system loss required for warm-up of the fuel cell and a warm-up output required for driving of a load including the drive motor during warm-up of the fuel cell.

Abstract: In order to assure drive of a drive motor, a boost operation of a boost device is appropriately performed by judging whether a voltage supplied from a fuel cell suffices a voltage required for driving the drive motor, thereby suppressing a switching loss by the boost device. A fuel cell system is a power source for driving a load. The system includes: a drive motor driven by an electric power; a fuel cell which generates electricity by an electrochemical reaction between an oxidizing gas containing oxygen and a fuel gas containing hydrogen and supplies an electric power to the drive motor; a first boost device which can boosts the voltage outputted from the fuel cell and supplies the boosted voltage to the drive motor; and boost control means which controls voltage boost performed by the first boost device according to the relationship between the fuel cell output voltage and the voltage required by the drive motor.

Abstract: Provided is a fuel cell system capable of supplying electric power to external loads without excess or deficiency even when switching between operation states is carried out. A warm-up timing judgment part judges whether or not it is time to carry out warm-up based on the temperature of a fuel cell stack. A target shift voltage determination part determines a target output voltage of the fuel cell stack used during a warm-up operation, and a voltage change speed determination part determines a voltage change speed based on electric power required from the fuel cell stack, the target output voltage of the fuel cell stack used during the warm-up operation which is output from the target shift voltage determination part and a current output voltage detected by a voltage sensor. A voltage decrease execution part carries out voltage decrease processing in accordance with the voltage change speed indicated by the voltage change speed determination part.

Abstract: A fuel cell system increases an output voltage of a fuel cell if an electric power generation command value Pref for the fuel cell abruptly reduces while the fuel cell is being warmed up at a low-efficiency operation, which has lower electric power generation efficiency than that of a normal operation. Thus, the surplus electric power Ws corresponding to the difference between an electric power generation amount Pmes of the fuel cell and the electric power generation command value Pref is stored into a capacitive component of the fuel cell, thereby matching the electric power supplied to an external load of the fuel cell (Pmes-Ws) with the electric power generation command value Pref. This makes it possible to conduct control not to supply the surplus electric power to the external load when the electric power required from the fuel cell suddenly reduces during the low-efficiency operation.

Abstract: A fuel cell system capable of carrying out a proper current limiting even when decreasing a cell voltage through, e.g., a rapid warm-up is provided. When a rapid warm-up is started, an acceptable cell-voltage value setting part sets a acceptable lowest-cell-voltage value in accordance with the operation state of a fuel cell. Meanwhile, a target cell-voltage value setting part sets an initial value for a target lowest-cell-voltage value. The target cell-voltage value setting part then compares a lowest cell voltage detected by a cell monitor with the set target lowest-cell-voltage value, and judges whether or not the lowest cell voltage is near the target lowest-cell-voltage value continuously for a given time period. If the result of the judgment is positive, the target cell-voltage value setting part updates the target lowest-cell-voltage value with a value obtained by decreasing the target lowest-cell-voltage value only by an update width.

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: In a fuel cell system comprising a fuel cell with plural cells and performing processing for limiting a supply current to a load by performing a compensation computation with respect to a system-request current corresponding to a system-request power requested by the system based on the lowest cell voltage in the cells, the compensation computation being performed for limiting the supply current through a PI compensation using, as a reference value, a current value of the system-request current as of the time when the lowest cell voltage falls below a predetermined lowest-cell-voltage acceptable value, values for gains in the PI compensation for limiting the supply current are different from values for gains in the PI compensation for restoring the supply current.

Abstract: The theme of the present invention is a fuel cell system capable of avoiding a disadvantage caused by the maintaining of a low-efficiency operation to improve the safety of a system operation. The fuel cell system is configured to perform the low-efficiency operation having a large power loss as compared with a usual operation at a predetermined low temperature to raise the temperature of a fuel cell in a short time as compared with the usual operation. The fuel cell system prohibits the low-efficiency operation to execute the usual operation, in a case where predetermined conditions are established at the predetermined low temperature. The predetermined conditions include a time when the generated power of the fuel cell cannot be consumed, a time when this generated power cannot be accumulated in a battery, or a time when the flooding of the fuel cell is generated.

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: Disclosed is a fuel cell system including a fuel cell which generates a power, and control means for decreasing the amount of a reactant gas to be supplied to the fuel cell to an amount smaller than that during normal power generation to realize low-efficiency power generation of the fuel cell. The control means sets the voltage lower limit value of the fuel cell so that the amount of an anode gas (pumping hydrogen) to be formed in a cathode of the fuel cell during the low-efficiency power generation is a predetermined amount or less.

Abstract: A control unit 80, when calculating a request current I0 according to a system request electric power Preq and calculating a target current I1 by correcting the request current I0 with PI compensation calculation based on a minimum cell voltage Vm detected by a cell monitor 101, variably changes a proportional gain Kp according to the current value at the present time when calculating a current limit value ?I as the amount of correction of a request current I0 according to the equation ?I=?V×Kp+??V×Ki, thereby enhancing controllability to control the current of a fuel cell 20 to a target current value I1. When controlling the current of a fuel cell by determining a target current value by correcting a request current by PI compensation using the difference between a minimum cell voltage and a threshold voltage, controllability to control the current of the fuel cell to the target current value can be enhanced.

Abstract: A fuel cell system includes: a fuel cell stack which receives a fuel gas and an oxidation gas to generate a power; an air compressor which supplies the oxidation gas to the fuel cell stack; and a controller which reduces the oxidation gas flow rate supplied from the air compressor to the fuel cell stack in consideration of discharge from a capacitance component of the fuel cell stack when decreasing the output voltage of the fuel cell stack. When the output voltage of the fuel cell stack has dropped, the fuel cell system can control a cell operation in consideration of the discharge from the capacitance component of the fuel cell stack to an external load.

Abstract: When a power generation instruction value for a fuel cell is reduced during warm-up of the fuel cell by a low power generation efficiency operation as compared to a normal operation and when supply of a reactant gas to the fuel cell cannot be controlled so as to follow the reduction of the power generation instruction value, the reactant gas supply to the fuel cell is reduced and the output voltage to the fuel cell is increased. Thus, it is possible to charge an excessive power equivalent to a difference between a fuel cell generation amount and the power generation instruction value into a capacitance component of the fuel cell, so that the power supplied to the external load of the fuel cell coincides with the power generation instruction value. Thus, when a power request for the fuel cell during the low-efficiency operation is suddenly reduced, it is possible to perform control so that the excessive power is not supplied to the external load.

Abstract: A fuel cell system includes: a fuel cell which generates electricity; and control means which supplies an output power from the fuel cell to a predetermined load power source while realizing a low-efficiency operation of the fuel cell, thereby driving and controlling the load power source. The control means sets the output voltage of the fuel cell during the low-efficiency operation to a value not smaller than the minimum drive voltage of the load power source.

Abstract: A converter device which is configured by connecting three converter circuits in parallel is provided between a secondary battery serving as a first power supply and a fuel cell serving as a second power supply. Two differential ammeters are placed on three reactors corresponding to the three converter circuits. A control unit includes a passing electric power calculation module which calculates electric power passing through the converter device on the basis of detected values of the two differential ammeters, an electric power equalization module which performs equalization of passing electric power between the respective converter circuits which constitute the converter device, a module for changing the number of drive phases which changes the number of drive phases of the converter device in response to the passing electric power, and a voltage conversion control module which controls the converter device and executes a desired voltage conversion.

Abstract: There is disclosed a fuel cell system or the like capable of sufficiently reducing an exhaust hydrogen concentration even in a case where a fuel cell is operated in a state of a low power generation efficiency. A bypass valve is arranged between an oxidation gas supply path and a cathode-off gas channel. In a state in which supply of an oxidation gas to a cathode falls short, pumping hydrogen is included in a cathode-off gas. Therefore, a valve open degree of the bypass valve is regulated, and a flow rate of bypass air is regulated to control the exhaust hydrogen concentration.