Abstract: A fuel cell installation containing a gas generation system, for the production of a hydrogen-containing gas, and a fuel cell system, which comprises a fuel cell, a compressor, an expander that is coupled with the compressor and a burner, the exhaust gases of which are directed to the expander. The gas generation system and the fuel cell system are designed as independent modules with respect to the supply of energy and process streams. Energy storage and energy conversion devices are arranged between the expander and the compressor in the fuel cell system.

Abstract: In the present fuel cell systems, fuel cell stacks operate on a fuel stream having a pressure that is below the pressure of the surrounding environment, for example below atmospheric pressure. In the event of a leak, the fuel stream will not escape to the surrounding atmosphere, but rather gases from the surrounding environment will leak into the fuel stream. The fuel stream generally cannot exit the fuel cell stack during normal operation. The fuel cell stack may be periodically purged by increasing the pressure of the fuel stream above the pressure of the surrounding environment and by permitting exit through the fuel stream outlet. A monitoring device can be employed to determine when to purge the fuel cell stack.

Abstract: In an improved electrochemical fuel cell assembly, a reactant flow path extends substantially linearly across the electrochemically active area of an electrode. The electrode has an in-plane nonuniform structure in its electrochemically active area as the active area is traversed in the direction of the substantially linear reactant flow path. Embodiments in which the structure of the fuel cell electrode varies substantially symmetrically along the reactant flow path are particularly preferred in fuel cells in which the flow direction of a reactant is periodically reversed.

Abstract: A hybrid use of a phase-locked-loop controller and a microprocessor-based controller to synchronize the phase angles of a three-phase AC power source, such as a static power converter, with those of a three-phase power grid. The phase-angle synchronization may enable the AC power source to be safely connected to the power grid to provide additional power capacity.

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

Abstract: An electric power generating system is provided that comprises a fuel cell stack having at least one solid polymer fuel cell, a cooling system having a coolant flow path that directs coolant to and from the stack, a fuel regulating system having a fuel flow path and for regulating the supply of fuel from a fuel supply to the stack via the fuel flow path, and a hydrogen concentration sensor. The sensor is located in the vicinity of the fuel regulating system and in the coolant flow path at a location downstream of the stack to detect hydrogen that may have been discharged by components of the power generating system in the coolant flow path upstream of the sensor, or by the fuel regulating system. In the event the measured hydrogen concentration exceeds a threshold level, steps are taken to reduce or stop the discharge of hydrogen from the power generating system.

Abstract: A membrane electrode assembly has two gas diffusion layers, two catalyst layers and an ion-exchange membrane interposed therebetween wherein the ion-exchange membrane is cast from a sulphonated polyether ketone/sulfone ionomer. Specifically, the ionomer can be represented as A-B-C wherein Further x, y, z represent the mole ratios of each moiety in the ionomer such that x is between 0.25 and 0.40; y is between 0.01 and 0.26; and z is between 0.40 and 0.67. Melt viscosity of the corresponding base polymer also affects performance in the fuel cell, particularly at values over 0.4 kNsm?2 as measured at 400° C., 1000 s?1. In preparing the membrane electrode assembly, the catalyst layers may be coated directly on the membrane and then bonded with two gas diffusion layers.

Abstract: Radio frequency identification (RFID) devices may be used to monitor various operating parameters in fuel cells. For example, RFID devices may be used to monitor the voltage of individual cells in a fuel cell stack and thus to check for voltage reversal conditions during stack operation.

Abstract: A significant problem in PEM fuel cell durability is in premature failure of the ion-exchange membrane and in particular by the degradation of the ion-exchange membrane by reactive hydrogen peroxide species. Such degradation can be reduced or eliminated by the presence of an additive in the anode, cathode or ion-exchange membrane. The additive may be a radical scavenger, a membrane cross-linker, a hydrogen peroxide decomposition catalyst and/or a hydrogen peroxide stabilizer. The presence of the additive in the membrane electrode assembly (MEA) may however result in reduced performance of the PEM fuel cell. Accordingly, it may be desirable to restrict the location of the additive to locations of increased susceptibility to membrane degradation such as the inlet and/or outlet regions of the MEA.

Abstract: In a system and method for the reduction of nitrogen oxides in the exhaust of an internal combustion engine, the exhaust line of the internal combustion engine contains a DeNOx catalytic converter, in which the nitrogen oxides are reduced by means of hydrogen that is produced on-board the vehicle. The DeNOx catalytic converter is incorporated into a temperature-controlled heat exchanger, allowing the DeNOx catalytic converter to be operated within a desired temperature range, thereby improving the level of conversion.

Abstract: A power module comprises first and second substrates carrying semiconductor devices and coupled to respective pluralities of heat exchange members without intervening thermally insulative structures. One or more heat exchange loops circulate a heat exchange medium thermally coupled to the heat exchange members. Substrates may function as integral bus bars.

Abstract: An electrochemical fuel cell stack comprises a plurality of fuel cell assemblies, wherein, each fuel cell assembly comprises a cell compressed between a pair of flow field plates, a perimeter seal circumscribing the cell and interposed between the pair of flow field plates, and a first diode, having an aspect ratio greater than 10:1, positioned adjacent to, and outside of, the perimeter seal along a first edge of the cell and interposed between the pair of flow field plates.

Abstract: A power module employs at least one capacitor electrically coupled across the input terminals to reduce voltage overshoot. The capacitor may be surface mounted to a high side collector plating area and a low side emitter plating area. The power module may employ a lead frame and terminals accessible from an exterior of a module housing, for making electrical couplings to externally located power sources and/or loads.

Abstract: A system including a current sensor to sense a current provided by an electronic power converter, the current sensor includes an output; an overcurrent detection circuit with an input coupled to an output of the current sensor; and a logic control circuit configurable to maintain the current provided by the electronic power converter in response to the sensed current having a short circuit magnitude, the logic control circuit including an input coupled to an output of the overcurrent detection circuit and at least one output coupled to at least one switch of the electronic power converter.

Abstract: The activity of catalysts used in promoting the oxidation of certain oxidizable species in fluids can be enhanced via electrochemical methods, e.g., NEMCA. In particular, the activity of catalysts used in the selective oxidation of carbon monoxide can be enhanced. A purification system that exploits this effect is useful in purifying reformate supplied as fuel to a solid polymer electrolyte fuel cell stack. The purification system comprises an electrolytic cell with fluid diffusion electrodes. The activity of catalyst incorporated in the cell anode is enhanced.

Abstract: Certain fuel cells (e.g., solid polymer electrolyte fuel cells) may temporarily exhibit below normal performance after initial manufacture or after prolonged storage. While normal performance levels may be obtained after operating such fuel cells for a suitable time period, this process can take of order of days to fully complete. However, exposing the cathode to a reductant (e.g., hydrogen) can provide for normal performance levels without the need for a lengthy initial operating period.

Abstract: Method and apparatus for determining transient power source defects versus nontransient, grid failures result in power being selectively applied to a DC bus for application to a load by either the power source, a rechargeable DC power supply, or both. The severity of the power interruption determines the degree to which the power will be supplied to a load through a power converter assembly by either an AC source or a rechargeable DC power supply.

Abstract: A power converter system advantageously employs a modular, bi-directionally symmetrical power converter assembly in a readily customizable configuration to interconnect a direct current power source to a three-phase alternating power grid. Connections external to the power converter assembly are selected to optimize the power converter system for a specific application, such as interconnecting a photovoltaic array to the three-phase electrical power grid. The electrical interconnections of various elements including isolation transformers, voltage sensors, and control switches are optimized to improve efficiency and reliability.

Abstract: Circuits and methods for use with an integrated circuit chip having internal back EMF estimation to control a permanent magnet synchronous motor includes an AC current feedback circuit, a scaling circuit, and a current regulator. Additionally, a speed regulator may be employed. In one embodiment, during operation at very low speed, the speed regulator is in an open loop control mode due to a back EMF detection limitation of the IC chip, and only the current regulator is active. A feedback current signal, together with a user-defined command current signal, serves the input of the current regulator, which controls the AC motor current and drives the motor speed from standstill. Once the motor speed reaches a certain level, the measured back EMF from the IC chip is sufficient to estimate the motor speed, which is compared with a user-defined command speed, and an error of the these two signals provides the input of a speed regulator.

Abstract: A three-phase connector carries all three phases in one connector and keeps the phases properly isolated from each other and the motor case. The three-phase connector has metal connector components that are spaced from one another and supported in a nylon over molding covering each of the connector components, except for upper and lower exposed ends of the connector components, which are each drilled and tapped to receive bolts. First and second connector components extend above and below a flange of the three-phase connector with their respective exposed upper and lower ends offset in different planes than the exposed upper and lower ends of the third connector component.