Abstract: A device is used to meter a gaseous medium, in particular air, by means of a plurality of metering valves, into a plurality of components of a fuel cell system used in a motor vehicle. All of the metering valves are arranged on a central middle block. The central middle block has at least one inlet opening for the gaseous medium, which is connected, via at least one passage, to in each case one connection point for each of the metering valves.

Abstract: Regenerative braking systems and methods for use in an electric vehicle, such as a battery-powered vehicle, a fuel cell vehicle, and a hybrid electric vehicle, including an electric motor system operable for generating torque to drive and control the electric vehicle, a traction controller operable for controlling the electric motor system, a brake system operable for generating torque to drive and control the electric vehicle, and a brake controller operable for controlling the brake system. Traction functions are strictly allocated to the traction controller, braking functions are strictly allocated to the brake controller, and the brake controller is subordinated to the traction controller. The regenerative braking systems and methods also including a communications system operable for transferring information between the traction controller and the brake controller.

Abstract: A fuel cell arrangement has at least one fuel cell with an anode and a cathode. A compressor arranged in the admission flow path of the cathode supplies air to the cathode, and a reforming unit with a reformer and a thermally coupled heating chamber is arranged in the admission flow path of the anode supplies the anode with a hydrogen-rich medium. A catalytic burner arranged in the cathode off-gas flow path between cathode and an expansion machine is coupled to drive the compressor. The heating chamber of the reforming unit or of an evaporator unit arranged in the admission flow path of the anode is arranged in the cathode off-gas flow path; and the expansion machine is arranged in the cathode off-gas flow path between catalytic burner and the heating chamber.

Abstract: A fuel cell system comprising a closed coolant path within a fuel cell; a humidifier comprising a humidification fluid flow path and a fuel and air gas supply passage continuous in, through and out of the humidifier; the humidification fluid flow path and the fuel and air gas supply passage separated by a water permeable membrane that is impervious to organic materials allowing water from the humidification fluid flow path to enter the fuel and air gas supply passage; and the humidifier connected to the fuel cell by a humidified air and fuel passageway. The water permeable membrane can be a keggin ion pillared &agr;-ZrP composite material. The coolant can be water and organic material mixture, such as glycol, thus allowing the coolant flow in temperatures below the freezing point.

Abstract: Field oriented induction motor system including a field oriented induction motor having an associated torque current and an associated flux current and a predetermined current ratio, wherein the predetermined current ratio is defined as the ratio of the torque current to the flux current, and wherein the predetermined current ratio is dependent upon the saturation state of the motor. A method for selecting the ratio of torque current to flux current for a field oriented induction motor including applying an allocation factor to the torque current and flux current, wherein the allocation factor is dependent upon the saturation state of the motor. The saturation state of the motor is determined based upon motor parameters.

Abstract: A device for compensating for fluctuations in the concentration of a gaseous constituent in the fuel gas stream of a dynamically operated fuel cell system, has a buffer component arranged in the fuel gas stream, provided downstream of a component of the fuel cell system which is to be protected. The buffer component takes up the gaseous constituent from the fuel gas stream in the event of the partial pressure rising and releases the gaseous constituent back into the fuel gas stream in the event of the partial pressure dropping. According to the invention, the buffer component contains a material for the adsorption or absorption of the gaseous constituent that has a take-up capacity which is dependent on the partial pressure.

Abstract: An integrated fuel cell and pressure swing adsorption system is disclosed for operating a solid polymer fuel cell on an enriched reactant stream. The fuel and/or oxidant streams may be enriched; for example, air and reformate streams may be oxygen and hydrogen enriched, respectively. The system may advantageously combine periodic reversal of the reactant flows through the fuel cell with use of an integrated pressure swing adsorption system.

Abstract: In a voltage measuring circuit for a composite fuel cell system, the potential of at least one point of the composite fuel cell system is detected by tapping the potential of such point, and feeding it to an input of an arrangement for evaluating the voltage. A potential shifting element is interposed between the at least one point of the composite fuel cell system and the input of the arrangement, which element is connected in series with a current sink or current source. A voltage supply circuit for such voltage measuring circuit of a composite fuel cell system comprising a plurality of individual fuel cells connected in series includes at least one voltage stabilization element connected in parallel with the circuit which is to be supplied with voltage by the composite fuel cell system. At least one current source or current sink is connected in series with this parallel circuit.

Abstract: Methods and related systems providing removal of heat from electric motors via fluid baths.

Abstract: A fuel cell system includes a fuel cell with a cathode space and an anode space that are separated by a polymer electrolyte membrane. The cathode space is supplied with an oxygen-containing gas, and the anode space is supplied with a hydrogen-containing gas. A gas-generation device is provided in which a hydrogen-rich reformate containing carbon monoxide, is produced from a fuel with the aid of steam reforming and/or partial oxidation. A gas-cleaning stage selectively oxidizes the carbon monoxide in the reformate on a suitable catalyst while oxygen is added; and a heat exchanger which is arranged in the gas-cleaning stage, has a cooling medium flowing through it and serves to dissipate thermal energy. According to the invention, to dissipate the thermal energy, the anode off-gas and/or cathode off-gas emerging from the fuel cell and/or a starting-material gas which is present in the fuel cell system flows through the heat exchanger.

Abstract: A device and method for detecting islanding of a grid connected inverter makes use of an injected white noise as a perturbing force on the output voltage of the inverter. The white noise is injected at least once in every cycle and can be generated at different rates in implementation. On loss of the grid, a frequency drift of the output voltage is detected and a positive feedback is activated that accelerates the drift.

Abstract: Systems and methods for controlling an induction motor including detecting a field weakening operation state of the motor, wherein the field weakening operation state is detected when a flux current, Id, in the motor is reduced to a predetermined fraction of its normal, non-voltage limited value. The systems and methods also including disabling an overmodulation operation state of the motor before said field weakening operation state is detected and enabling the overmodulation operation state of the motor after said field weakening operation state is detected.

Abstract: A method and apparatus for improving the speed measurement quality in systems having multi-pole machines is taught. The method compensates for pole misalignment by moving average techniques.

Abstract: In a process for operating a fuel cell system with a water balance, a hydrogen-containing medium or a mixture of mediums is reformed in a reforming reactor with a water requirement, by adding water to a hydrogen rich reformate. The reformate is fed to an anode region of a fuel cell and reacts with oxygen from a cathode region of the fuel cell, forming water in the fuel cell. The the water required for the reforming reaction and/or the water balance of the fuel cell system is coupled directly to the oxidation rate of the partial combustion of the hydrogen-containing medium or the mixture of mediums in an oxidizing unit upstream of the reforming reactor.

Abstract: In an electrochemical fuel cell, a sufficient quantity of catalyst, effective for promoting the reaction of reactant supplied to an electrode, is disposed within the volume of the electrode so that a reactant introduced at a first major surface of the electrode is substantially completely reacted upon contacting the second major surface. Crossover of reactant from one electrode to the other electrode through the electrolyte in an electrochemical fuel cell is thereby reduced.

Abstract: A method is provided for treating electrocatalyst particles and using the treated electrocatalyst for improving performance in an electrochemical fuel cell. The treatment method comprises impregnating pores of the electrocatalyst particles with an impregnant wherein the pores comprise micropores which have an aperture size less than 0.1 micron. The impregnant is preferably ion-conducting and may comprise an organic acid, an inorganic acid, or a polymer. Alternatively, or in addition, the impregnant has an oxygen permeability greater than that of water. The method of impregnating the electrocatalyst particles preferably comprises the steps of contacting the electrocatalyst particles with an impregnant and subjecting the electrocatalyst particles to a vacuum and/or an elevated pressure above atmospheric pressure. The treated electrocatalyst particles are incorporated into an electrochemical fuel cell.

Abstract: Fuel cell systems and control methods including a fuel cell and a second energy source, such as a battery that is adapted to supplement the fuel cell. In addition, the fuel cell system utilizes a single bipolar switching module, such as an IGBT six pack module that is configured to implement a DC/DC converter, such as a DC/DC boost converter, for both the fuel cell and the battery. The fuel cell system also makes use of a controller that is configured to control either or both of input current and output voltage of the DC/DC converter.

Abstract: A motor vehicle drive train assembly for achieving multiple effective ratios from a single ratio transaxle enables application of a fixed ratio transaxle, such as used in electric vehicle drive trains, to a multi-speed requirement, for example, in airport ground support equipment. Multiple configurations are enabled by varying the relative speed of the outputs through the differential of the transaxle, such as bringing one of the outputs to zero, or by using another motor to control the speed of one of the outputs.

Abstract: An electrochemical fuel cell stack with improved reactant manifolding and sealing includes a pair of separator plates interposed between adjacent membrane electrode assemblies. Passageways fluidly interconnecting the anodes to a fuel manifold, and interconnecting the cathodes to an oxidant manifold, comprise at least one fluid passageway formed between adjoining non-active surfaces of the pairs of separator plates. The passageways extend through one or more ports penetrating the thickness of one of the plates thereby fluidly connecting the manifold to the opposite active surface of that plate, and the adjacent electrode. The ports comprise walls that have surfaces that are angled more than 0 degrees and less than 90 degrees with respect to the direction of fluid flow in the fluid passageway upstream of the port. During operation, electrochemical fuel cell stacks comprising fluid ports with angled walls benefit from reduced pressure loss.

Abstract: A fuel cell system comprises a fuel cell having an anode and a cathode, a fuel feed line connected to the anode, an oxidant feed line connected to the cathode and a cathode exhaust line. A water collecting unit is connected to the cathode exhaust line, and a cooling circuit comprising a radiator is configured to cool the fuel cell. A nozzle is connected to the water collecting unit and configured to spray water onto the radiator.