Patent application number | Description | Published |
20100047663 | FUEL CELL SYSTEM - There is disclosed a fuel cell system which can control an output current of a fuel cell even if an error occurs in split flow control of an oxidizing gas. The fuel cell system includes a fuel cell and a feed device for supplying the oxidizing gas under pressure to the fuel cell. A feed channel is connected to a discharge channel by a bypass channel so that the oxidizing gas flows while bypassing the fuel cell. The system includes a regulator valve and a bypass valve which adjust the split flow of the oxidizing gas to the bypass channel and the fuel cell. When the regulator valve or the bypass valve has an error, a controller stops the control of the output current of the fuel cell by control of the regulator valve and switches the control to a control of the output current of the fuel cell by control of the feed device. | 02-25-2010 |
20100055522 | FUEL CELL SYSTEM - 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. | 03-04-2010 |
20100068575 | FUEL CELL SYSTEM - 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. | 03-18-2010 |
20100136451 | FUEL CELL SYSTEM AND CURRENT CONTROL METHOD OF SAME - A control unit | 06-03-2010 |
20100159342 | FUEL CELL SYSTEM AND ITS CONTROL METHOD - 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. | 06-24-2010 |
20100203409 | FUEL CELL SYSTEM AND ITS CONTROL METHOD - 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. | 08-12-2010 |
20100248055 | FUEL CELL SYSTEM AND METHOD FOR LIMITING CURRENT THEREOF - 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. The system-request current can be securely limited in any operation statuses, and in addition, the supply current can be made rapidly responsive during the limitation of the current, while the supply current can be stably converged during the current restoration. | 09-30-2010 |
20100266916 | FUEL CELL SYSTEM - 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 ΔV 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 ΔV 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 ΔV control is carried out has not come yet, and automatically starts the I-V control without carrying out the ΔV control. | 10-21-2010 |
20100266920 | FUEL CELL SYSTEM - 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. | 10-21-2010 |
20100273075 | FUEL CELL SYSTEM - 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. | 10-28-2010 |
20100279187 | FUEL CELL SYSTEM AND FUEL CELL VEHICLE - There is disclosed a fuel cell system having a motor which can be driven and generate a regenerative power by receiving the supply of a power, wherein an influence on power supply control is decreased. The fuel cell system fuel cell system comprises a fuel cell which generates a power by an electrochemical reaction of a fuel gas and an oxidant gas; a motor which can be driven and generate the regenerative power by receiving the supply of a power; an inverter which converts a direct-current power output from the fuel cell into an alternate-current power to supply the power to the motor, thereby controlling the driving of the motor; a battery which is connected to the motor in parallel with the fuel cell, and which can be charged with the power generated by the fuel cell and the regenerative power generated by the motor and which can discharge the charged powers to the motor; a rotation number detector which detects the rotation number of the motor; and a control unit which determines whether or not to allow the stop of the control by the inverter with respect to the motor based on the present rotation number of the motor. The control unit compares the present rotation number of the motor with a threshold value which varies in accordance with operation modes of the fuel cell, to perform the determination. | 11-04-2010 |
20100291447 | FUEL CELL SYSTEM - 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. | 11-18-2010 |
20100291452 | FUEL CELL SYSTEM - 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. | 11-18-2010 |
20110256461 | FUEL CELL SYSTEM, ESTIMATION DEVICE OF AMOUNT OF ANODE GAS TO BE GENERATED AND ESTIMATION METHOD OF AMOUNT OF ANODE GAS TO BE GENERATED - 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 B | 10-20-2011 |
20120013183 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system includes: a secondary cell; a voltage converter provided between the secondary cell and a load; a fuel cell; an FC relay that turns on and off electrical connection between the fuel cell and the shared electrical path; an electrical-leakage detector that detects electrical leakage in an electrical system; and a control portion that performs determination regarding electrical leakage. The control portion has: start means for starting the fuel cell by raising voltage of the fuel cell from a starting voltage to an operation voltage that is lower than an open-circuit voltage; and electrical leakage determination means for performing the determination regarding electrical leakage after a predetermined time elapses, when the FC relay is closed while a voltage difference between the voltage of the fuel cell and voltage supplied from the voltage converter to the load is greater than a predetermined threshold value. | 01-19-2012 |
20120013289 | FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system starts a fuel cell by setting the voltage supplied to a secondary cell from a voltage transformer at an open-circuit voltage of the fuel cell, and raising the voltage of the fuel cell from a starting voltage to the open-circuit voltage, in the case where the secondary cell is expected to be overcharged if the secondary cell receives electric power. In the case where the secondary cell is not expected to be overcharged if the secondary cell receives electric power, the system starts the fuel cell by setting the voltage supplied from the voltage transformer at a high-potential-avoiding voltage that is lower than the open-circuit voltage of the fuel cell at or after the elapse of a predetermined time following the output of a command to close an FC relay, and raising the voltage of the fuel cell from the starting voltage to the high-potential-avoiding voltage. | 01-19-2012 |
20120015267 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system includes a fuel cell that has a plurality of fuel unit cells, and a control portion that controls voltage of the fuel cell. The control portion has: start means for starting the fuel cell by raising the voltage of the fuel cell from a starting voltage to a high-potential-avoiding voltage that is lower than an open-circuit voltage; and command means for further raising the voltage of the fuel cell beyond the high-potential-avoiding voltage if cell voltage of at least one of the plurality of fuel unit cells is lower than or equal to a certain voltage after a certain time elapses after the voltage of the fuel cell is raised to the high-potential-avoiding voltage. | 01-19-2012 |
20120019191 | FUEL CELL SYSTEM, AND ELECTRIC VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - A fuel cell system comprising a fuel cell that generates electricity through an electrochemical reaction between a fuel gas and an oxidant gas, and a control portion that controls amount of electricity generation at a time of starting the fuel cell, characterized in that the control portion has voltage drop control means for controlling speed of dropping a starting voltage of the fuel cell from an open-circuit voltage to a high-potential-avoiding voltage according to an initial voltage of the fuel cell and to a pre-determined threshold voltage that is lower than the high-potential-avoiding voltage, when the starting voltage of the fuel cell is dropped from the open-circuit voltage to the high-potential-avoiding voltage. | 01-26-2012 |
20120021257 | FUEL CELL SYSTEM, CONTROL METHOD FOR THE FUEL CELL SYSTEM, AND VEHICLE EQUIPPED WITH THE FUEL CELL SYSTEM - 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. | 01-26-2012 |
20120274137 | FUEL CELL SYSTEM AND CONTROL METHOD THEREFOR - During an intermittent operation of the fuel cell, a demanded FC voltage calculation portion calculates a predetermined voltage that is below a heightened potential avoidance threshold voltage as a demanded FC voltage, and outputs the voltage to a converter. When during the intermittent operation of the fuel cell, a deviation obtained by subtracting a generated power of the fuel cell from a system's allowable power that is allowable in the fuel cell system becomes less than or equal to a value 0, the demanded FC voltage correction portion corrects a command value provided for the converter so that the deviation becomes equal to the value 0. | 11-01-2012 |
20150064589 | FUEL CELL SYSTEM AND ITS CONTROL METHOD - 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. | 03-05-2015 |