A fuel cell system of the present invention can suppress an excessively wet or dry state of a fuel cell stack so as to thereby ensure the durability of the fuel cell stack. The fuel cell system supplies an oxidant gas with a reduced flow rate per unit time and for a long time period if the rate of voltage decrease of the stack becomes faster than a threshold rate, and supplies the oxidant gas with an increased flow rate per unit time and for a short time period if the rate of voltage decrease becomes slower than a threshold rate.

An inspection method of a fuel battery by using an electrical charge existing in a fuel battery stack includes a supplying step in which the electrical charge is supplied from an external power supply to the fuel battery stack.

Methods and circuits for a device for interrupting concentration-related polarisation phenomenon and for self-cleaning of electromembrane processes by application of asymmetric inverse-polarity pulses with high intensity and variable frequency are described. The device, a bipolar switch, is based on the use of solid-state electronics to carry out polarity inversion in a range of frequencies, intensities and pulse widths to prevent or reduce formation of precipitates on the surfaces of the membranes. The inversion protocol, with a frequency that varies as a function of the appearance of dirt on the membranes, as measured by the decrease in voltage or electrical resistance of the membrane cell during electromembrane processes, is also provided. This device and configuration provides application of modulated and stable high-intensity pulses using a second power source. Electromembrane processes can be updated by replacing electrodes, suitable for polarity inversion, and adding a second power source and the bipolar switch described.

A method for controlling startup of a fuel cell vehicle is provided. The method includes starting to adjust supply of hydrogen and air to a fuel cell and setting a control voltage of a side of a main bus end of a converter disposed between the main bus end and a high-voltage battery to a predetermined lowest control voltage. An output voltage of the side of the main bus end of the fuel cell and the control voltage of the side of the main bus end of the converter are then compared to adjust an amount of air supply to the fuel cell based on the comparison.

A fuel cell system includes: a fuel cell; a reformer to generate a hydrogen-containing gas; an electric power generation raw material supply unit; a reforming material supply unit configured to supply at least one of reforming water and reforming air, to the reformer; an oxidizing gas supply unit to supply an oxidizing gas to a cathode of the fuel cell; a combustor to ignite an exhaust gas discharged from the fuel cell; and a controller. In an operation stop process of the fuel cell system, the controller causes the oxidizing gas supply unit to supply the oxidizing gas, causes the electric power generation raw material supply unit and the reforming material supply unit to intermittently supply the electric power generation raw material and at least one of the water and the air to the reformer, and causes the ignitor to perform an ignition operation.

A control method for driving of a fuel cell is provided. The method includes determining whether power generation of the fuel cell is stopped and when the power generation of the fuel cell is stopped, monitoring voltages of multiple unit cells included in the fuel cell. A degree of defect of the unit cells is determined based on the monitored voltages of the unit cells.

A method for controlling the operation of an electrochemical device having at least one operating organ, comprising the steps of: receiving measurements related to the operation of the electrochemical device, and estimating at least diagnostics data based on said measurements, estimating prognostics data based on said diagnostics data and providing operation instructions to control said operating organ of the electrochemical device, said operation instructions being optimized with respect to said estimated diagnostics and prognostics data.

Methods and systems may provide for technology to predict a future increase in power demand on a fuel cell based on route data associated with a vehicle powered by the fuel cell and reduce an operating temperature of the fuel cell prior to the future increase in power demand. The technology may also provide supplemental power from a battery to the vehicle while the operating temperature of the fuel cell is being reduced.

A method for controlling the operation of an electrochemical device having at least one operating organ, comprising the steps of: receiving measurements related to the operation of the electrochemical device, and estimating at least diagnostics data based on said measurements, estimating prognostics data based on said diagnostics data and providing operation instructions to control said operating organ of the electrochemical device, said operation instructions being optimized with respect to said estimated diagnostics and prognostics data.

A method of cleaning power cells in an array of power cells, comprising coupling at least one first power cell to second power cells in an array of power cells and causing the second power cells to drive the at least one first power cell with a voltage to clean catalyst on the at least one first power cell.