Abstract: When an overvoltage is generated in one converter and an overvoltage is not generated in another converter, the whole system continues to operate using a power source connected to the other converter. Here, it is determined whether a reason for an overvoltage is an open-circuit fault in a relay connecting the two converters or a fault in an overvoltage detecting circuit of one converter, and system control suitable for the fault is performed.

Abstract: The fuel cell system comprises a fuel gas tank, a fuel cell configured to generate electricity with oxidizing gas and fuel gas supplied from the fuel gas tank, a current sensor configured to detect output current from the fuel cell, a voltage sensor configured to detect output voltage from the fuel cell, and a controller. The controller is configured to determine that fuel gas quality does not meet predetermined standard quality when the controller determines output from the fuel cell has decreased using current values detected by the current sensor and voltage values detected by the voltage sensor after filling operation of the fuel gas into the fuel gas tank.

Abstract: A fuel cell system includes a fuel cell, an anode gas supply system, an anode gas circulatory system, a cathode gas supply-discharge system, a gas-liquid discharge passage, a gas-liquid discharge valve configured to open and close the gas-liquid discharge passage, a flow-rate acquisition portion, and a controlling portion. After the controlling portion instructs the gas-liquid discharge valve to be opened, the controlling portion executes a normal-abnormality determination such that, when a discharge-gas flow rate of anode gas is a predetermined normal reference value or more, the controlling portion determines that the gas-liquid discharge valve is opened normally, and when the discharge-gas flow rate is lower than the normal reference value, the controlling portion determines that the gas-liquid discharge valve is not opened normally.

Abstract: A fuel cell vehicle comprises a fuel cell, a power storage device, a drive motor, a temperature sensor configured to measure a temperature of the fuel cell, a detector configured to detect an operation condition of the fuel cell, and a controller. At a start time of the fuel cell, in a case where the temperature of the fuel cell detected by the temperature sensor is below a freezing point, when an output condition of the fuel cell shown by the detected operation condition of the fuel cell continuously corresponds to a predetermined low output condition for a predetermined reference time period or longer, the controller sets a driving state of the fuel cell vehicle to a first driving state that stops power generation of the fuel cell, drives the drive motor by using only the power storage device as a power source and limits a motor output of the drive motor to be equal to or lower than a predetermined first upper limit output.

Abstract: A power supply method carried out in a system that includes a fuel cell, a secondary battery, a motor, and an auxiliary for the fuel cell includes controlling an intermittent operation by which execution and stoppage of power generation by the fuel cell is switched intermittently to supply power to electric power loads including the motor and the auxiliary, determining whether or not an abnormality occurs in the secondary battery during the intermittent operation, instructing the motor to regenerate power on a condition that it is determined that an abnormality occurs in the secondary battery in the determination of whether or not the abnormality occurs, and supplying power, which is obtained by carrying out the regeneration, to the auxiliary.

Abstract: A drive system includes a drive device including an electric power generator; a fuel cell; a secondary battery; a fuel cell step-up converter including a diode; a relay connected to wiring between the fuel cell step-up converter and the drive device; a secondary battery step-up converter connected; a fuel cell voltage sensor; a secondary battery voltage sensor; and a controller. The controller stops the secondary battery step-up converter when a short-circuit fault of the diode is detected, disconnects the relay when a voltage of the fuel cell is higher than a voltage of the secondary battery after stopping the secondary battery step-up converter, and when the voltage of the secondary battery is higher than or equal to the voltage of the fuel cell, executes a voltage control process which increases the voltage of the fuel cell relative to the voltage of the secondary battery, and disconnects the relay.

Abstract: A control device is configured to control a first boost converter and a second boost converter. The control device is configured such that, when a prescribed state where an output of the second boost converter cannot be made at a ratio of an output voltage to an input voltage in the second boost converter to be equal to or more than a predetermined value is detected, the control device calculates a target output voltage of a fuel cell by using an voltage on an input side or an output side of the second boost converter measured by a measuring portion and a first value which is equal to or larger than a minimum boost ratio of the first boost converter, and controls the fuel cell so that an output voltage of the fuel cell is equal to or lower than the target output voltage.

Abstract: A fuel cell system FCS includes a fuel cell 10, a high voltage circuit 21 for driving an electromotor 42, and a relay 41 for electrically connecting or blocking the fuel cell 10 to or from the high voltage circuit 21. A control unit 50 obtains insulation decrease information in accordance with a request for starting the fuel cell, and performs, when a specified insulation decrease occurred region is not a fuel cell region SE1 including the fuel cell and the cooling circuit, conductivity reduction process on cooling liquid using a conductivity reduction unit 113 before having a relay 41 connect, and has the relay 41 connect after completing the conductivity reduction process.

Abstract: When an overvoltage is generated in one converter and an overvoltage is not generated in another converter, the whole system continues to operate using a power source connected to the other converter. Here, it is determined whether a reason for an overvoltage is an open-circuit fault in a relay connecting the two converters or a fault in an overvoltage detecting circuit of one converter, and system control suitable for the fault is performed.

Abstract: A drive system includes a drive device including an electric power generator; a fuel cell; a secondary battery; a fuel cell step-up converter including a diode; a relay connected to wiring between the fuel cell step-up converter and the drive device; a secondary battery step-up converter connected; a fuel cell voltage sensor; a secondary battery voltage sensor; and a controller. The controller stops the secondary battery step-up converter when a short-circuit fault of the diode is detected, disconnects the relay when a voltage of the fuel cell is higher than a voltage of the secondary battery after stopping the secondary battery step-up converter, and when the voltage of the secondary battery is higher than or equal to the voltage of the fuel cell, executes a voltage control process which increases the voltage of the fuel cell relative to the voltage of the secondary battery, and disconnects the relay.

Abstract: A method of disconnecting a secondary battery which disconnects the secondary battery from an electric power supply path in an electric power supply system performs shutting off a flow of a current to a secondary battery side through a converter after it is detected that there is an abnormality in the secondary battery, and when it is determined that the voltage of the power storage unit is equal to or less than the voltage of the secondary battery by the predetermined value, maintaining a connection of the secondary battery to the electric power supply path and when it is determined that the voltage of the power storage unit is greater than the voltage of the secondary battery by the predetermined value, operating a relay to disconnect the secondary battery from the electric power supply path.

Abstract: A power supply method carried out in a system that includes a fuel cell, a secondary battery, a motor, and an auxiliary for the fuel cell includes controlling an intermittent operation by which execution and stoppage of power generation by the fuel cell is switched intermittently to supply power to electric power loads including the motor and the auxiliary, determining whether or not an abnormality occurs in the secondary battery during the intermittent operation, instructing the motor to regenerate power on a condition that it is determined that an abnormality occurs in the secondary battery in the determination of whether or not the abnormality occurs, and supplying power, which is obtained by carrying out the regeneration, to the auxiliary.

Abstract: A method of disconnecting a secondary battery which disconnects the secondary battery from an electric power supply path in an electric power supply system performs shutting off a flow of a current to a secondary battery side through a converter after it is detected that there is an abnormality in the secondary battery, and when it is determined that the voltage of the power storage unit is equal to or less than the voltage of the secondary battery by the predetermined value, maintaining a connection of the secondary battery to the electric power supply path and when it is determined that the voltage of the power storage unit is greater than the voltage of the secondary battery by the predetermined value, operating a relay to disconnect the secondary battery from the electric power supply path.

Abstract: A shock detection system with a vehicle at rest includes a parking mechanism for locking rotation of a drive shaft which rotates a wheel of the vehicle, a revolution sensor for detecting a revolution speed of the drive shaft, and a shock detector for detecting a shock to the vehicle based on a magnitude and a frequency of variation in detection values of the revolution speed of the drive shaft detected by the revolution sensor in a state where the rotation of the drive shaft is locked by the parking mechanism.

Abstract: If a main stop valve of a fuel gas tank is not opened, it becomes possible to display a remaining level of fuel gas. A remaining fuel level displaying method for the fuel cell system comprises: if the main stop valve is opened, then calculating a remaining level of fuel gas in the fuel gas tank using a pressure value acquired from the pressure sensor, and displaying the calculated remaining level of the fuel gas on a display device, and if the main stop valve is closed, then displaying on the display device a remaining level of the fuel gas that was stored into a memory at a time when the main stop valve was shut off.

Abstract: An object is to provide a technique that suppresses excessive water drainage from a fuel cell. A water drainage device for fuel cell that drains water from inside of a fuel cell, includes: a purge gas supply system; an operation unit; a water drainage controller; and a water content acquirer. The operation unit receives a water drainage command from a user to give an instruction of purging out water from inside of the fuel cell by the purge gas supply system. When the water content obtained by the water content acquirer is equal to or lower than a predetermined value, the water drainage controller performs either one of: (i) a process of invalidating the water drainage command received by the operation unit; and (ii) a process of changing a processing condition of the purge process to decrease an amount of water drained by the purge process, compared with an amount of water drainage when the obtained water content is higher than the predetermined value.

Abstract: If a main stop valve of a fuel gas tank is not opened, it becomes possible to display a remaining level of fuel gas. A remaining fuel level displaying method for the fuel cell system comprises: if the main stop valve is opened, then calculating a remaining level of fuel gas in the fuel gas tank using a pressure value acquired from the pressure sensor, and displaying the calculated remaining level of the fuel gas on a display device, and if the main stop valve is closed, then displaying on the display device a remaining level of the fuel gas that was stored into a memory at a time when the main stop valve was shut off.

Abstract: A shock detection system with a vehicle at rest includes a parking mechanism for locking rotation of a drive shaft which rotates a wheel of the vehicle, a revolution sensor for detecting a revolution speed of the drive shaft, and a shock detector for detecting a shock to the vehicle based on a magnitude and a frequency of variation in detection values of the revolution speed of the drive shaft detected by the revolution sensor in a state where the rotation of the drive shaft is locked by the parking mechanism.