A voltage control system includes a converter device, and a controller configured to set a duty ratio according to a current target value so as to cause the converter device to repeatedly perform a boost operation according to the duty ratio. The controller is configured to set the duty ratio by use of a basic term including a feedforward term, and an additional term, the feedforward term being derived by use of a measured value of a magnitude of an input of a reactor provided in the converter device and a measured value of a magnitude of an output of the reactor or by use of respective target values of the magnitude of the input and the magnitude of the output in the reactor, the additional term being derived by use of the variation of the current target value during one cycle.

A vehicle includes: a power storage device; a regenerative fuel cell including a water electrolysis device and a fuel cell; a motor generator configured to be driven using electric power of at least one of the power storage device and the fuel cell; a driving wheel configured to be driven by the motor generator; and a control device configured to perform regeneration control of generating regenerative electric power by the motor generator at a time of braking of the vehicle. The control device is configured to supply the regenerative electric power to the water electrolysis device when an SOC of the power storage device is equal to or greater than a predetermined value at a time of performing the regeneration control.

An operating control method of a fuel cell stack is provide. The method includes diagnosing performance of a fuel cell stack based on an output current of the fuel cell stack, when an operating voltage of the fuel cell stack is within a predetermined diagnostic voltage range. Whether a recovery operation of the fuel cell stack is required is determined based on the diagnosed performance of the fuel cell stack and the voltage of the fuel cell stack is reduced, when the recovery operation of the fuel cell stack is required to recover performance of the fuel cell stack.

A stack fuel cell array featuring paired fuel-cell systems combined to generate 540 VDC for a rotorcraft. Power from the hydrogen-based fuel cells is provided to the rotorcraft. A rated electrical load of the rotorcraft helps determine how many paired fuel-cell systems are needed during any fuel-cell systems failures. Each of the paired fuel-cell systems is coupled to an electrical load of the rotorcraft. The system detects any fuel cell failures and removes other working fuel cells as needed to balance the electrical system.

A fuel-cell system at 540 VDC for powering an electrical load of a rotorcraft with a first fuel cell and a second fuel cell. Each fuel cell is configured identically and features a positive electrical node and a negative electrical node. Each fuel cell is configured to provide one half of the electrical load of the rotorcraft and one half of the voltage of the electrical load.

A fuel cell system includes a fuel cell, auxiliary machinery, a tank, a storage amount detection unit that detects a measured value representing the amount of fuel gas stored in the tank, a secondary battery, a power accumulation amount detection unit that detects an amount of power accumulated in the secondary battery, a feed detection unit, and a control unit. The control unit stops the supply of the fuel gas to the fuel cell when the measured value is less than a threshold value, electrically disconnects the secondary battery from the auxiliary machinery when the amount of accumulated power is less than a lower limit amount of accumulated power, and electrically connects the secondary battery to the auxiliary machinery after the feeding of the fuel gas to the tank is detected.

A vehicle system includes a motor, a first device connected to the motor and configured to supply the motor with power, a fuel cell connected to the first device and configured to charge the first device, a second device connected to the fuel cell, a first converter interposed between the fuel cell and the first device and configured to adjust a voltage from one of the fuel cell or the first device and to supply power to the other, a second converter interposed between the fuel cell and the second device and configured to adjust a voltage from the second device and to apply the adjusted voltage to the fuel cell, and a third converter interposed between the first device and the second device and configured to adjust a voltage from one of the first device or the second device and to supply power to the other.

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.

A fuel cell vehicle according to the present disclosure includes an insulation voltage detector provided in a coolant circuit; and an ECU having a storage unit that stores an insulation voltage value detected by the insulation voltage detector. The ECU determines a coolant leak when the insulation voltage value detected by the insulation voltage detector is larger than the insulation voltage value that is obtained when an ignition was turned off a last time, the s insulation voltage values obtained when the ignition was turned off the last time being stored in the storage unit.

An apparatus for measurement control of a cell voltage of a fuel cell includes: terminals connected between the cells of a fuel cell connected in series; first resistors connected in series to the terminals; capacitors each connected in parallel between the first resistors to store voltages; switches connected to the first resistors to switch into a closed or an open state; a second resistor connected in series between a lowest cell among the cells and a semiconductor GND to provide a path for a current flow when an inverse voltage occurs in the cells; a diode connected in parallel to the second resistor to provide a path for a current flow when an inverse voltage does not occur in the cells; and a controller to change the state of each switch depending on a cell voltage measurement or open-wire diagnosis mode and perform cell voltage measurement and open-wire diagnosis.