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 voltage control system includes: a converter controlling portion; a current value acquisition portion; and a voltage value acquisition portion. The converter controlling portion sets a duty ratio in a present cycle by adding an addition term to a feedforward term, the addition term being determined by use of a current deviation, which is a difference between a target value of an output current in the present cycle and a current measured value in a previous cycle, and the duty ratio in the previous cycle, the addition term being corresponding to an increase of the output current in the present cycle.

Accelerated testing protocols that can be utilized for determining and projecting the durability of SOFC cathodes are described. The accelerated testing protocols can be carried out under simulated operation conditions so as to provide in a matter of a few hundred hours data that can correlate to the condition of the cathode following operation of the cell over the course of a typical operation life span of several thousand hours. A testing protocol can include cycling a SOFC from OCV to operating potential at a predetermined current density. Each cycle can be relatively short, for instance less than one minute.

A method of operating a fuel cell assembly comprising a plurality of fuel cells connected together for collectively providing power to a load, each fuel cell including an anode and a cathode, the method comprising selectively providing an electrical connection between the anode and the cathode of at least one of the fuel cells of the assembly for lowering the voltage across the fuel cell independent of the load.

By processing circuitry executing a program recorded in a storage unit, a control method for a fuel cell system includes calculating a load output and calculating a maximum output, comparing the load output with the maximum output, and controlling, in a case that the load output exceeds the maximum output, the fuel cell system to decrease a power storage output used by a load, by increasing a power generation output.

In the fuel cell vehicle provided with the motor and configured to drive the motor with power of at least one of the fuel cell 1 and the battery, the fuel cell having a DC voltage of less than 60 V is disposed in the rear portion of the vehicle and the battery is disposed in the front relative to the fuel cell.

A system and method for controlling a start of a fuel cell vehicle are provided. The method includes supplying hydrogen and air to a fuel cell and operating a converter so that a voltage on a high-voltage bus is constant, wherein the converter is disposed between a high-voltage battery and the high-voltage bus which is connected to an output terminal of the fuel cell. The voltage on the high-voltage bus is maintained at a preset lowest control voltage and the voltage on the high-voltage bus is adjusted based on a result comparing a preset lower-limit operational voltage of an inverter with an inverter detection voltage. The inverter is disposed between the high-voltage bus and a drive motor, and the inverter detection voltage is detected on a terminal of the inverter which is connected to the high-voltage bus.

A fuel cell system includes a fuel cell, an electrical storage device, a fuel-cell-side converter, an electrical-storage-device-side converter, and a controller. The fuel cell is to output fuel cell voltage. The fuel-cell-side converter is configured to apply the fuel cell voltage to a load in a direct connection state or configured to apply a stepped-up fuel cell voltage to the load. The electrical-storage-device-side converter is configured to apply a stepped-up electrical storage device voltage to the load. The controller is configured to control duty of the electrical-storage-device-side converter so that the fuel cell voltage changes smoothly in a case where a state in which the fuel cell voltage is controlled by the fuel-cell-side converter is switched to a state in which the fuel-cell-side converter is set to the direct connection state and the fuel cell voltage is controlled by the electrical-storage-device-side converter.

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 fuel cell system according to the present invention comprises a control apparatus which performs performance restoration processing for a catalyst layer by decreasing the output voltage of a fuel cell to a predetermined voltage. When an oxide film formed on the catalyst layer during power generation of the fuel cell contains, in addition to a first oxide film that can be removed by decreasing the output voltage of the fuel cell to a first oxide film removal voltage, a second oxide film that can be removed by decreasing the output voltage of the fuel cell to a second oxide film removal voltage which is lower than the first oxide film removal voltage, the control apparatus estimates the amount of the second oxide film and performs performance restoration processing with a set voltage being equal to or lower than the second oxide film removal voltage only when it determines that the estimated amount exceeds a predetermined amount A.