Abstract: A fuel cell system includes: a fuel cell; a fuel gas path supplied with fuel and allowing a part of fuel gas discharged from the fuel cell to circulate; an exhaust mechanism discharging the reacted fuel gas to an outside; a circulation mechanism circulating the fuel gas; and a control unit configured to temporarily stop circulation of the fuel gas by the circulation mechanism when determining that discharge from the exhaust mechanism is not normal, drive the circulation mechanism so that the fuel gas circulates at a first circulation speed when determining that the discharge is not normal and a parameter relating to water vapor in the fuel gas path is equal to a predetermined value or greater, and drive the circulation mechanism so that the fuel gas circulates at a second circulation speed greater than the first circulation speed when determining that the discharge is normal.

Abstract: A fuel cell system, comprising: a compressor that is placed in a supply flow path arranged to supply a cathode gas to a fuel cell; a first motor-operated valve that is placed between the fuel cell and the compressor in the supply flow path; a first stepping motor that is provided in the first motor-operated valve; a second motor-operated valve that is placed in a discharge flow path arranged to discharge the cathode gas from the fuel cell; a second stepping motor that is provided in the second motor-operated valve; and a controller that is configured to control power generation by the fuel cell and to input drive pulses into the first stepping motor and the second stepping motor, so as to open the first motor-operated valve and the second motor-operated valve at a start of the fuel cell and close the first motor-operated valve and the second motor-operated valve at a stop of the fuel cell, wherein the first stepping motor is driven by input of the drive pulse to generate a torque to open and close the first m

Abstract: An object is to provide a technique of enhancing the accuracy of estimation of the water content of a fuel cell on the occurrence of localized drying of an electrolyte membrane. In a fuel cell system, until satisfaction of a second condition indicating that localized drying of the electrolyte membrane is eliminated after satisfaction of a first condition indicating that localized drying of the electrolyte membrane occurs, a water content estimator performs a second water content estimation process that estimates the water content of the fuel cell based on an output current value of the fuel cell, in place of a first water content estimation process that estimates the water content of the fuel cell based on an impedance of the fuel cell.

Abstract: An objection is to provide a technology by which a decline in the starting performance of a fuel cell system may be controlled in a low-temperature environment. A control method of a fuel cell system includes a temperature acquisition step of acquiring a temperature of the fuel cell at start-up of the fuel cell; and an exhaust gas control step of restricting, when the temperature of the fuel cell is below a predetermined value, a flow rate of an exhaust gas flowing into a flow path configuring portion that configures at least a part of a flow path of the exhaust gas of the fuel cell as compared to the flow rate of the exhaust gas flowing into the flow path configuring portion when the temperature of the fuel cell is equal to or less than the predetermined value.

Abstract: The vehicle control apparatus configured to control a vehicle includes a fuel cell configured to supply electric power to the vehicle; an air conditioning mechanism having a heater core; a first medium circuit; a radiator installed in the first medium circuit; a bypass circuit formed in the first medium circuit to make a bypass flow of the cooling medium bypassing the radiator; a regulation valve installed in the first medium circuit to regulate a ratio of a flow rate of the cooling medium going through the radiator to a flow rate of the cooling medium going through the bypass circuit; a second medium circuit; a cooling medium circulation pump installed in at least one of the first medium circuit and the second medium circuit; a temperature acquisition module; a warm-up controller; and a state switchover structure.

Abstract: A method of discharging water from a mobile object, which includes a fuel cell, a gas-liquid separator, and a circulation pump, comprises: an inclined state detection step of detecting an inclined state of the mobile object with respect to a horizontal plane; a scavenging start step of starting to supply scavenging gas at a predetermined first supply flow rate to a gas flow path in the fuel cell, by driving the circulation pump; and a supply flow rate increase step of increasing, when the mobile object is in a predetermined inclined state in which an outlet of the gas flow path is directed upward against a direction of gravity, a rotational speed of the circulation pump so that the supply flow rate of the scavenging gas is increased to a second supply flow rate higher than the first supply flow rate after a predetermined period from starting to supply the scavenging gas.

Abstract: A valve control apparatus controls a valve for adjusting a pressure of a reaction gas supplied to a fuel cell. The valve control apparatus includes: an estimation portion that estimates a valve effective cross-sectional area of the valve; and an opening adjustment portion that adjusts opening degree of the valve with control amount corrected based on the valve effective cross-sectional area estimated by the estimation portion.

Abstract: A fuel cell system 10 includes a fuel cell 20, gas supply systems 30, 40, which supply gases to the fuel cell 20, and a controller 60, which controls the gas supply systems 30, 40. During a non-operation period of the fuel cell 20, the controller 60 controls the gas supply systems 30, 40 to carry out the scavenging treatment. If the scavenging treatment is interrupted by an operation performed by a user, then the controller 60 controls the gas supply systems 30, 40 and restarts the scavenging treatment after a predetermined time elapses from the interruption.

Abstract: The present invention provides a fuel cell system capable of suppressing the accumulation of impurities in a hydrogen system even when a hydrogen pump stops. A fuel cell system 100 includes a hydrogen pump 4, which is provided in a hydrogen gas circulation flow path 3 and which circulates a hydrogen off-gas discharged from the outlet side of a hydrogen electrode 1a of a fuel cell 1 to the inlet side of the hydrogen electrode 1a, a discharge valve 61, through which the hydrogen off-gas flowing in the hydrogen gas circulation flow path 3 is discharged out of the hydrogen gas circulation flow path 3, a determination section 81, which determines whether the hydrogen pump 4 is stopped, and a control unit 80, which controls the opening/closing of the discharge valve 61.

Abstract: An object is to provide a technique that a current state of a fuel cell may be detected more accurately. A fuel cell system includes a controller, a fuel cell, and an impedance measurer that may measure an impedance of the fuel cell. The controller obtains a first impedance value that expresses the impedance of the fuel cell in a predetermined state, acquires a second impedance value that expresses the impedance of the fuel cell that is measured by the impedance measurer during operation control of the fuel cell, and performs operation control of the fuel cell using the first impedance value and the second impedance value.

Abstract: There is provided a fuel cell system. The fuel cell system includes a gas pump that is configured to have a rotating body and circulate an exhaust gas discharged from a fuel cell and is provided in a circulation passage configured to connect a discharge passage of the exhaust gas with a fuel gas supply passage. When temperature of the fuel cell is higher than a reference temperature that is a temperature that allows water to be introduced in a supercooled state into the gas pump, the fuel cell system controls the rotation speed of the rotating body of the gas pump to a first rotation speed corresponding to a power generation demand for the fuel cell. When the temperature of the fuel cell is not higher than the reference temperature, the fuel cell system controls the rotation speed of the rotating body of the gas pump to a second rotation speed that is lower than the first rotation speed.

Abstract: An object is to readily provide an output limit of a fuel cell by using temperature of a cooling medium, while improving the startability of a fuel cell. When a cell voltage obtained from an end-portion cell of a fuel cell is equal to or lower than a first threshold value, a controller of a fuel cell system sets an output limit amount used for output limit of the fuel cell to be smaller than an output limit amount according to temperature of a cooling medium measured by a temperature measurement unit.

Abstract: An object is to provide a technique of enhancing the accuracy of estimation of the water content of a fuel cell on the occurrence of localized drying of an electrolyte membrane. In a fuel cell system, until satisfaction of a second condition indicating that localized drying of the electrolyte membrane is eliminated after satisfaction of a first condition indicating that localized drying of the electrolyte membrane occurs, a water content estimator performs a second water content estimation process that estimates the water content of the fuel cell based on an output current value of the fuel cell, in place of a first water content estimation process that estimates the water content of the fuel cell based on an impedance of the fuel cell.

Abstract: At an ordinary stop time of a fuel cell system, a controller of the fuel cell system completes an ordinary stop process that includes at least one of a water drainage process that discharges water from at least one of the fuel gas flow path and the oxidizing gas flow path and a cathode sealing process that seals the oxidizing gas flow path, and subsequently stops the fuel cell system. When the fuel cell system satisfies a predetermined emergency stop condition, the controller does not perform at least part of the ordinary stop process but performs an emergency stop process that sets the fuel cell system to be restarted after elapse of a first time period since a stop of the fuel cell system and subsequently stops the fuel cell system. The controller restarts the fuel cell system after elapse of the first time period since stop of the fuel cell system and performs a restart process that performs the ordinary stop process.

Abstract: A fuel cell system comprises a fuel cell; a fuel cell controlling converter; an oxidizing gas supplier that is configured to supply an oxidizing gas to the fuel cell; and a controller that is configured to control a voltage and a current value of the fuel cell. In a first power generation state, the controller sets the voltage and the current value of the fuel cell according to a required output, based on a current-voltage characteristic of the fuel cell. In a second power generation state, the controller sets the voltage and the current value of the fuel cell according to the required output and a required amount of heat, to a voltage and a current value that provide a lower power generation efficiency than a power generation efficiency in the first power generation state. The controller reduces the required amount of heat in a process of changing over a power generation state from the second power generation state to the first power generation state.

Abstract: A fuel cell system, comprising: a compressor that is placed in a supply flow path arranged to supply a cathode gas to a fuel cell; a first motor-operated valve that is placed between the fuel cell and the compressor in the supply flow path; a first stepping motor that is provided in the first motor-operated valve; a second motor-operated valve that is placed in a discharge flow path arranged to discharge the cathode gas from the fuel cell; a second stepping motor that is provided in the second motor-operated valve; and a controller that is configured to control power generation by the fuel cell and to input drive pulses into the first stepping motor and the second stepping motor, so as to open the first motor-operated valve and the second motor-operated valve at a start of the fuel cell and close the first motor-operated valve and the second motor-operated valve at a stop of the fuel cell, wherein the first stepping motor is driven by input of the drive pulse to generate a torque to open and close the first m

Abstract: A fuel cell system suppresses the deterioration of an electrolyte membrane of a fuel cell. The fuel cell system comprises: a temperature rise speed calculation unit for calculating a target temperature rise speed of the fuel cell using a temperature of the fuel cell and a water content of the fuel cell; and a drive control unit for controlling a drive of the cooling water pump using the temperature rise speed of the fuel cell and the target temperature rise speed calculated by the temperature rise speed calculation unit. The drive control unit controls the drive of the cooling water pump such that a circulation amount of the cooling water is decreased when the temperature rise speed of the fuel cell is below the target temperature rise speed and controls the drive of the cooling water pump such that the circulation amount of the cooling water is increased when the temperature rise speed of the fuel cell is equal to or greater than the target temperature rise speed.

Abstract: If a required voltage which corresponds to a required power has reached a boundary voltage, which is an oxidation-reduction potential of platinum, which constitutes a catalyst of a fuel cell, the fuel cell system performs crossover-avoidance control that holds an FC instruction voltage for the fuel cell at the boundary voltage, and absorbs the gap between the required voltage and the FC instruction voltage by using a secondary battery.

Abstract: The invention is provided to reliably restore generated voltage that has declined due to clogging of water in a fuel cell stack. A method of operating a fuel cell system having a fuel cell stack that generates electricity through an electrochemical reaction between a fuel gas including hydrogen gas and an oxidation gas, wherein when a generated voltage of the fuel cell stack declines, the water-in-cell content of the fuel cell stack is adjusted so that a variation in cell pressure loss in the fuel cell stack decreases based on a characteristic curve of the water-in-cell content of the fuel cell stack and the cell pressure loss of the fuel cell stack.

Abstract: A method of discharging water from a mobile object, which includes a fuel cell, a gas-liquid separator, and a circulation pump, comprises: an inclined state detection step of detecting an inclined state of the mobile object with respect to a horizontal plane; a scavenging start step of starting to supply scavenging gas at a predetermined first supply flow rate to a gas flow path in the fuel cell, by driving the circulation pump; and a supply flow rate increase step of increasing, when the mobile object is in a predetermined inclined state in which an outlet of the gas flow path is directed upward against a direction of gravity, a rotational speed of the circulation pump so that the supply flow rate of the scavenging gas is increased to a second supply flow rate higher than the first supply flow rate after a predetermined period from starting to supply the scavenging gas.