Abstract: A fuel cell system has a fuel cell stack generating electricity with a reactive gas supplied thereto and a controller supplying to the fuel cell stack the reactive gas whose pressure is higher than a normal operational pressure on condition that a temperature of the fuel cell stack is equal to or less than a predetermined threshold temperature and that a moisture content of the fuel cell stack is equal to or less than a predetermined threshold value. Where a supply pressure of the reactive gas is raised, an amount of moisture taken away by the reactive gas becomes less, and thus, water balance within the fuel cell stack shifts toward accumulation of moisture contained in the reactive gas into the film-electrode joined body. However, since the moisture content of the fuel cell stack is equal to or less than the predetermined threshold value, the system can improve the starting performance of the fuel cell stack at low temperature while suppressing flooding.

Abstract: A method for operating a fuel cell power plant to supply power to an internal load and an external load, includes the steps of evaluating power needs of the internal and external loads to determine a fixed IDC value sufficient to supply the needs; providing auxiliary power to the internal load and output power to the external load so as to maintain operation of the fuel cell power plant at the fixed IDC value; and adjusting at least one of the auxiliary power to the internal load and output power to the external load so as to maintain operation of the fuel cell power plant at the fixed IDC value. Operation within a preselected voltage range is also provided.

Abstract: A direct oxidation fuel cell (DOFC) having a liquid fuel and an anode electrode configured to generate power. The anode electrode includes a gas diffusion layer (GDL) and a microporous layer, such that a decrease in the porosity of the GDL achieves an increase in the power density of the DOFC.

Abstract: According to one embodiment, a fuel cell apparatus includes a cell stack of an active direct methanol type, and a DC-DC converter configure to receive output voltage of the cell stack and to control an output current of the cell stack so that the output voltage of the cell stack becomes greater than a lower-limit threshold Vt and the output current of the cell stack lies in a range of I1 to I2 (<I1).

Abstract: A fuel cell system includes; a fuel cell which generates electricity by using a fuel gas and an oxidant gas as reaction gases; current control means which controls current of a fuel cell; voltage control means which controls voltage of the fuel cell; and heat value control means which calculates a heat value required by the fuel cell system and decides a target current value of the current control means and a target voltage value of the voltage control means so as to generate the calculated necessary heat amount, thereby controlling the heat value. Thus, it is possible to supply a heat required for the fuel cell system without increasing the size of the fuel cell system.

Abstract: A fuel cell system which prevents the deterioration of the fuel cell stack when feeding of the oxidant gas is paused under a load to perform a fuel conservation operation. Controller shuts down oxidant gas compressor and cooling water circulating pump to execute fuel conservation operation at a low fuel cell system load. The controller gives a current draw instruction to electric power controller. In the fuel conservation operation, electric power controller draws a current larger than zero from fuel cell stack, and keeps the total charge drawn per unit time constant or substantially constant.

Abstract: In an ECU, a coolant fan performs cooling operation such that a control DUTY value is limited by a control DUTY value according to tolerable noise level of the cooling fan based on a vehicle speed in a case in which the temperature in the high-voltage battery is lower than a predetermined limitation for highest temperature. In a case in which the temperature in the high-voltage battery is higher than the predetermined limitation for highest temperature, the cooling fan performs the cooling operation by using an energy storage device cooling operation requirement value and an IPU cooling operation requirement value such that performance in the high-voltage battery is not affected. By doing this, a temperature controlling apparatus for batteries in which it is possible to cool the battery and solve temperature difference among a plurality of batteries can be provided.

Abstract: A fuel cell system comprises a fuel cell, a reactant gas supply device, and a capacitor which supplies a power to various devices when the fuel cell is in a temporary power generation stop state. The fuel cell system drives the reactant gas supply device based on a predetermined current instruction value to supply a reactant gas to the fuel cell, thereby generating the power. Such a fuel cell system comprises a control device which judges whether or not the current instruction value is below a water balance zero current value when the water content of the fuel cell is below a predetermined threshold and the stored electric charge of the capacitor is a predetermined threshold or more. If affirmative judgment is obtained, the control device switches the power generation state of the fuel cell to the temporary power generation stop state.

Abstract: A fuel cell or fuel cell stack heater using resistive heat. A resistive conductor (preferably some type of metal wire) is attached to a source of electricity such as a battery. The resistive conductor is in proximity with the fuel cell or stack so that when the resistive conductor is heated, the cell or stack will also become hot. An insulating material surrounds the outside of the fuel cell or stack, so that it encloses the cell or stack and the resistive conductor. The insulating material will capture heat from the resistive conductor and any waste heat given off by the operation of the fuel cell or stack. A means for modifying the amount of electrical current in the resistive conductor is attached to the apparatus. When the fuel cell or stack reaches the desired temperature, the means is employed to reduce or turn off current in the resistive conductor.

Abstract: The membrane electrode assembly is virtually divided into a plurality of small regions arranged along the flow of reactive gases. A current density 132 and a transfer amount 136 of water in an n?1 region are calculated referring to the maps defining a relationship between a power generation environment and a current density and a relationship between the power generation environment and a transfer amount of water, on the basis of power generation environments 122 and 128 transmitted from a pre-stage. Consumption amounts 138 and 146 of the reactive gases are calculated from the current density 132. A power generation environment transmitted to an n region is calculated by reflecting the consumption amounts 138 and 146 of the reactive gases and the transfer amount 136 of water (140, 144, 148, 150). Power generation environments and power generation states are sequentially predicted as to all the small regions.

Abstract: Provided is a fuel cell system capable of accurately estimating I-V characteristics of a fuel cell. An impedance measurement section measures an impedance of the fuel cell and obtains a voltage drop caused by a direct-current resistance. An air stoichiometry judgment section detects the amount of oxidant gas supplied to the fuel cell and thereby judges whether or not the air stoichiometry ratio is 1 or higher at this time point. An estimated I-V characteristics line creation section determines that the remaining voltage component consists entirely of an activation voltage when the air stoichiometry ratio notified by the air stoichiometry judgment section is 1 or higher, while determining that the remaining voltage drop component includes the combination of the activation overvoltage and voltage drop corresponding to the change in the electromotive voltage when the notified air stoichiometry ratio is below 1.

Abstract: There is provided a fuel cell system for mobile applications. An exemplary fuel cell system comprises a fuel cell and a DC/DC transformer that is coupled to the fuel cell and that can be coupled to an energy storage unit. The exemplary fuel cell system also comprises a control and regulation unit connected to the fuel cell and to the DC/DC transformer, the control and regulation unit being adapted to store performance characteristics of a fuel cell that has not aged.

Abstract: An IR resistance of each of unit cells is measured, and a highest unit cell voltage as a threshold voltage is set based on the IR resistance and load current. The setting of the highest unit cell voltage uses map data that approximates current-voltage characteristics of a unit cell when the fuel gas is insufficiently supplied. In that case, the highest unit cell voltage is determined based on the voltage with respect to the load current obtained from the map data, and the IR loss calculated from the IR resistance and the load current. This highest unit cell voltage is compared with the measured unit cell voltage. If the unit cell voltage is below the highest unit cell voltage, the power generation of the fuel cell is stopped or restrained.

Abstract: A system for optimizing the purge cycle of a fuel cell stack responsive to the performance of the fuel cell. The system includes a controller that measures a process parameter indicative of the rate at which water is being produced in the fuel cell. If the measured value exceeds a threshold value, then the purge assembly is automatically actuated.

Abstract: A method of evaluating an electrochemical cell for a metallic contaminant-caused defect. The electrochemical cell is configured for use with an implantable medical device and includes an anode, a solid cathode and a liquid electrolyte. The method includes storing the cell at an elevated temperature following assembly for accelerating corrosion of possible metallic contaminants. A parameter of the cell related to cell voltage is then measured. An evaluation is made as to whether the cell is defective based upon this measured parameter.