A fuel cell system, including: an electric power generation control unit; an insulation-resistance measurement signal generation unit configured to generate a voltage-divided AC signal obtained by dividing an amplitude of a measurement AC signal; and an insulation resistance measurement unit configured to measure a resistance value of the insulation resistance, in which when the insulation resistance measurement unit detects, in a state where a voltage is maintained during an intermittent operation of the electric power generation control unit, an excessive noise state indicating a change in which a range of fluctuations of the peak value of the voltage-divided AC signal exceeds a predetermined allowable range of fluctuations, the insulation resistance measurement unit instructs the electric power generation control unit to change a fluctuation frequency of an output voltage of the fuel cell from a current frequency and then measures the resistance value of the insulation resistance.

A process for starting a PEM fuel cell module includes blowing air through the cathode side of the module using external power. An amount hydrogen is released into the anode side of the module under a pressure greater than the pressure of the air on the cathode side, while the anode is otherwise closed. Cell voltages in the module are monitored for the appearance of a charged state sufficient to start the module. When the charged state is observed, the module is converted to a running state.

Provided is an aging device for a fuel cell stack, capable of reliably detecting the generation of a negative voltage during aging while also achieving a cost reduction with reduced cell monitors. The voltage of an end cell on the reactant gas inlet side, in which the voltage is likely to become the highest, is monitored alone, so that the generation of a negative voltage in each of a plurality of individual central cells other than the end cell is estimated.

A fuel cell system is configured to generate power by supplying anode gas and cathode gas to a fuel cell. The fuel cell system includes a load connected to the fuel cell and an IV estimation unit configured to change an output current of the fuel cell with a predetermined width by adjusting power supplied to the load during the warm-up of the fuel cell. The fuel cell system is configured to estimate an IV characteristic of the fuel cell on the basis of at least two sets of an output current value and an output voltage value detected while the output current is changed. The fuel cell system includes an IV estimation stop unit configured to stop the execution of the IV estimation on the basis of an output of the fuel cell during the execution of the IV estimation.

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 for operating a fuel cell includes a controller configured to derive an output limit value of the fuel cell through an interval average value corresponding to an average of output values of the fuel cell for a designated time and a cumulative average value corresponding to an average of the output values of the fuel cell until the current point in time after starting to operate the fuel cell, and to control operation of the fuel cell based on the derived output limit value.

A hydrogen purging device for a fuel cell system includes a humidifier that humidifies dry air supplied from an air blower, using moist air discharged from a cathode of a stack and supplies the humidified air to the cathode. A water trap and a hydrogen recirculation blower are sequentially connected to an outlet of an anode, wherein a hydrogen outlet of the water trap and an inlet of the humidifier are connected by a cathode-hydrogen purging line for purging hydrogen to the cathode so that the hydrogen discharged from the anode of the fuel stack is purged to the cathode during idling or during normal driving.

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, including: an electric power generation control unit; an insulation-resistance measurement signal generation unit configured to generate a voltage-divided AC signal obtained by dividing an amplitude of a measurement AC signal; and an insulation resistance measurement unit configured to measure a resistance value of the insulation resistance, in which when the insulation resistance measurement unit detects, in a state where a voltage is maintained during an intermittent operation of the electric power generation control unit, an excessive noise state indicating a change in which a range of fluctuations of the peak value of the voltage-divided AC signal exceeds a predetermined allowable range of fluctuations, the insulation resistance measurement unit instructs the electric power generation control unit to change a fluctuation frequency of an output voltage of the fuel cell from a current frequency and then measures the resistance value of the insulation resistance.

An air supply system for fuel cells includes a fuel cell, an air supply line connected to a cathode of the fuel cells to supply external air to the cathode of the fuel cell, an air pressure sensor provided on the air supply line, and configured to measure a pressure in the air supply line, a determiner configured to determine whether correction for the air pressure is necessary, and a controller connected to the determiner and configured to perform the correction for the air pressure sensor by performing voltage control of the fuel cell, upon determining that the correction for the air pressure sensor is necessary.