Abstract: One embodiment of the present invention is a unique aircraft. Another embodiment is a unique propulsion system for an aircraft. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for aircraft and aircraft propulsion systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

Abstract: A method of operating a fuel cell includes the step of selectively connecting and disconnecting the fuel cell to at least one electrical load dependent at least in part upon at least one of a fuel cell voltage, a fuel cell current and a fuel cell temperature.

Abstract: A hybrid fuel cell system comprising a solid-oxide fuel cell system, a proton exchange membrane fuel cell system, a hydrocarbon reformer and a hydrogen separator. A large PEM provides output power, such as motive power for a vehicle, using hydrogen storage that may be resupplied from a separate hydrogen refilling station or from the onboard reformer. The SOFC is preferably small and provides heat and exhaust water that, when recycled into the reformer, allow the reformer to operate endothermically without requiring atmospheric air, thus excluding nitrogen from the reformate stream. Alternatively, the reformer and SOFC are stationary at a base station and the PEM is aboard the vehicle. The SOFC and reformer have sufficient capacity to recharge hydrogen storage in the vehicle in a relatively short period of time, such as overnight.

Abstract: A hybrid fuel cell system comprising a solid-oxide fuel cell system, a proton exchange membrane fuel cell system, a hydrocarbon reformer and a hydrogen separator. A large PEM provides output power, such as motive power for a vehicle, using hydrogen storage that may be resupplied from a separate hydrogen refilling station or from the onboard reformer. The SOFC is preferably small and provides heat and exhaust water that, when recycled into the reformer, allow the reformer to operate endothermically without requiring atmospheric air, thus excluding nitrogen from the reformate stream. Alternatively, the reformer and SOFC are stationary at a base station and the PEM is aboard the vehicle. The SOFC and reformer have sufficient capacity to recharge hydrogen storage in the vehicle in a relatively short period of time, such as overnight.

Abstract: Apparatus and method for operating a fuel cell system including a hydrocarbon catalytic reformer and close-coupled fuel cell stack by recycling anode syngas into the reformer in a range between 60% and 95% of the total syngas. At equilibrium conditions, oxygen required for reforming of hydrocarbon fuel is derived from endothermically reformed water and carbon dioxide in the syngas. Reforming temperature is between about 650° C. to 750° C. The stack exit temperature is about 800° C. to 880° C. such that the required endotherm can be provided by the sensible heat of the recycled syngas. The stack has approximately equal anode and cathode gas flows in opposite directions, resulting in cooling from both the anodes and cathodes.

Abstract: An electrical power system includes an alternating current (AC) power source configured to output an AC signal, a single phase pulse-width modulated (PWM) rectifier coupled to the AC power source and to an electrical load; a DC link capacitor coupled in parallel to the load and the PWM rectifier; and an active ripple energy storage circuit.

Abstract: A fuel cell APU system comprising a plurality of fuel cell modules connected in parallel. Each module includes a local controller connected to a master controller that coordinates the modules to achieve a desired power output at any given time. Each module is operated within an output range to maximize efficiency of the system. When load demand on a first module exceeds the desired output range of the module, an additional module is brought online in parallel with the first. As the load increases further, additional modules are brought online in cascade fashion to permit all modules to be operated efficiently. If a module is disabled, it is automatically switched out of service and replaced by a standby module. The master controller keeps track of the total operating time of each module and varies the sequence in which different modules are brought into service to balance deterioration among the modules.

Abstract: A fuel cell APU system comprising a plurality of fuel cell modules connected in parallel. Each module includes a local controller connected to a master controller that coordinates the modules to achieve a desired power output at any given time. Each module is operated within an output range to maximize efficiency of the system. When load demand on a first module exceeds the desired output range of the module, an additional module is brought online in parallel with the first. As the load increases further, additional modules are brought online in cascade fashion to permit all modules to be operated efficiently. If a module is disabled, it is automatically switched out of service and replaced by a standby module. The master controller keeps track of the total operating time of each module and varies the sequence in which different modules are brought into service to balance deterioration among the modules.

Abstract: A solid-oxide fuel cell system having a relatively large primary fuel cell sub-assembly for steady-state operation and a relatively small secondary fuel cell sub-assembly which is rapidly heatable to a threshold operating temperature to a) produce usable power in a short time period, b) cascade a hot exhaust into the primary fuel cell sub-assembly to assist in preheating thereof, and c) provide steam into the primary fuel cell sub-assembly to prevent coking of the anodes thereof. As the primary sub-assembly reaches its threshold temperature, it too begins to generate electricity and continues to self-heat and to be heated by the secondary sub-assembly. Preferably, the secondary sub-assembly continues to provide electricity in complement with the primary sub-assembly until the primary sub-assembly reaches full power, at which time the secondary sub-assembly may be shut down or switched to standby status for fuel efficiency, as desired.

Abstract: An auxiliary power system providing electric power from a fuel cell stack at a nominal steady state output experiences an instantaneous voltage drop when maximum load is called for, which voltage drop can damage the fuel cell stack. Also, the required power increase cannot be provided for a short lag period during which the fuel cell fueling is ramped up. In the present invention, an electricity storage device, such as a battery, is provided in parallel with the fuel cell stack to meet the burst power demand during the fuel cell ramp-up lag. Various alternative control mechanisms are disclosed to assure that the necessary power is provided while also protecting both the fuel cell stack and the battery from damaging voltage swings. A vehicular application with a shared vehicle battery is also disclosed.

Abstract: A fuel cell system in accordance with the invention includes a single, central electronic controller (CPU) for controlling at least the Air Handling sub-system, the Reformer sub-system, the Power Electronics sub-system, and the Customer Interface sub-system. The central controller provides a central location for easier serviceability; increases data transport efficiency by eliminating lengthy links between distributed controllers; eliminates the need for multiple mechanical enclosures; allows for controller thermo conditioning in one mechanical enclosure; and reduces parasitic power losses by employing a single power supply.

Abstract: A system for co-generation of electricity combining a hydrocarbon catalytic reformer, an SOFC assembly and a generator driven by a gas turbine. The fuel cell assembly recycles a high percentage of anode exhaust gas into the reformer. Oxygen for reforming is derived from water in an endothermic process. The stack exit temperature is normally above 800° C. DC power from the fuel cell assembly and AC power from the gas turbine generator are directed to a power conditioner. Anode exhaust gas including carbon monoxide and hydrogen is divided into a plurality of portions by which heat may be added to the reforming, gas turbine, and cathode air heating processes. Water may be recovered from the exhaust. A power system in accordance with the invention is capable of operating at a higher total efficiency than either the fuel cell component or the gas turbine component alone.

Abstract: A system for desulfurizing hydrocarbon fuel for a reformer and SOFC stack in an SOFC system. The system comprises a liquid phase desulfurizer for low-temperature desulfurization of an amount of liquid fuel ahead of reformer/stack startup and for continuous removal of large refractory sulfur-containing compounds from low-temperature fuel thereafter during operation of the reformer/stack,and gas phase desulfurizer for continuous high-temperature desulfurization of a stream of vaporized hydrocarbon fuel downstream of the liquid phase desulfurizer. The gas phase desulfurizer may be either upstream or downstream of the reformer.

Abstract: A hybrid fuel cell system comprising a solid-oxide fuel cell system, a proton exchange membrane fuel cell system, a hydrocarbon reformer and a hydrogen separator. A large PEM provides output power, such as motive power for a vehicle, using hydrogen storage that may be resupplied from a separate hydrogen refilling station or from the onboard reformer. The SOFC is preferably small and provides heat and exhaust water that, when recycled into the reformer, allow the reformer to operate endothermically without requiring atmospheric air, thus excluding nitrogen from the reformate stream. Alternatively, the reformer and SOFC are stationary at a base station and the PEM is aboard the vehicle. The SOFC and reformer have sufficient capacity to recharge hydrogen storage in the vehicle in a relatively short period of time, such as overnight.

Abstract: A power system used for transferring power between a plurality of power sources is provided. A power system according to the present invention is comprised of a plurality of power sources, wherein each source includes a pair of terminals. The power system is further comprised of a power converter, including a pair of switches for each one of the plurality of power sources. Each of these switches are connected to the respective pairs of terminals for each source. Each switch further includes an associated diode, and each switch pair includes a common node. The power converter further includes a plurality of inductors numbering one less than the number of power sources, wherein each inductor is connected across two of the common nodes. The power converter further includes a control unit configured to actuate the switches in accordance with, and to carry out, one of a plurality of modes of operation.

Abstract: A method of operating a fuel cell includes the step of selectively connecting and disconnecting the fuel cell to at least one electrical load dependent at least in part upon at least one of a fuel cell voltage, a fuel cell current and a fuel cell temperature.

Abstract: A method of operating a fuel cell includes the step of selectively connecting and disconnecting the fuel cell to at least one electrical load dependent at least in part upon at least one of a fuel cell voltage, a fuel cell current and a fuel cell temperature.

Abstract: A fuel cell system in accordance with the invention includes a single, central electronic controller (CPU) for controlling at least the Air Handling sub-system, the Reformer sub-system, the Power Electronics sub-system, and the Customer Interface sub-system. The central controller provides a central location for easier serviceability; increases data transport efficiency by eliminating lengthy links between distributed controllers; eliminates the need for multiple mechanical enclosures; allows for controller thermo conditioning in one mechanical enclosure; and reduces parasitic power losses by employing a single power supply.

Abstract: Apparatus and method for operating a fuel cell system including a hydrocarbon catalytic reformer and close-coupled fuel cell stack by recycling anode syngas into the reformer in a range between 60% and 95% of the total syngas. At equilibrium conditions, oxygen required for reforming of hydrocarbon fuel is derived from endothermically reformed water and carbon dioxide in the syngas. Reforming temperature is between about 650° C. to 750° C. The stack exit temperature is about 800° C. to 880° C. such that the required endotherm can be provided by the sensible heat of the recycled syngas. The stack has approximately equal anode and cathode gas flows in opposite directions, resulting in cooling from both the anodes and cathodes.

Abstract: A system for co-generation of electricity combining a hydrocarbon catalytic reformer, an SOFC assembly and a generator driven by a gas turbine. The fuel cell assembly recycles a high percentage of anode exhaust gas into the reformer. Oxygen for reforming is derived from water in an endothermic process. The stack exit temperature is normally above 800° C. DC power from the fuel cell assembly and AC power from the gas turbine generator are directed to a power conditioner. Anode exhaust gas including carbon monoxide and hydrogen is divided into a plurality of portions by which heat may be added to the reforming, gas turbine, and cathode air heating processes. Water may be recovered from the exhaust. A power system in accordance with the invention is capable of operating at a higher total efficiency than either the fuel cell component or the gas turbine component alone.