Abstract: A method of controlling a permanent magnet turbogenerator/motor includes providing a protected load connected in parallel with the turbogenerator/motor through a pulse width modulated inverter configured in a first operating mode to supply controlled current from the turbogenerator/motor to a utility electrical power source, and selectively connected to the utility electrical power source through an isolation device, monitoring the utility electrical power source, and automatically disconnecting the protected load from the utility electrical power source while reconfiguring the pulse width modulated inverter in a second operating mode to supply controlled voltage to the protected load when a fault is detected in the utility electrical power source.

Abstract: A gas turbine engine includes a rotatable impeller having a plurality of vanes with inlet and outlet ends. A plurality of diffuser channels are spaced apart radially beyond the outlet ends. A movable source of gaseous fuel is positioned adjacent the inlet ends of the vanes. The movable source of gaseous fuel is movable as a function of the rotational speed of the impeller, whereby the flow of gaseous fuel injected from the movable source is ejected from the outlet ends of the vanes into a selected one of the plurality of diffuser channels to facilitate combustion.

Abstract: A method and system to automatically restart a permanent magnet turbogenerator/motor when a fatal fault is detected. The automatic restart logic includes time constraints and limitations on the number of iterations, and is useful regardless of whether the permanent magnet turbogenerator/motor is in a grid connect mode or a standalone mode, and regardless of how the fatal fault originates or is detected. Additional control logic is utilized to handle grid transients and over load conditions to prevent a fatal fault from occurring by using time constraints and an iterative process, together with a brake resistor to control DC bus voltage.

Abstract: A system and method for modular control of a multi-fuel turbogenerator include separate controllers for controlling fuel supplied to the combustor and power output from the generator. The power controller generates a fuel command based on the required turbine exhaust temperature, where the fuel command is independent of the particular fuel being used. Fuels may include natural gas, diesel, propane, waste gas, or gasoline, for example. The power controller communicates the fuel command and the airflow or calculated air/fuel ratio to the fuel controller which selects an appropriate mode of operation for the injectors. Injector operating modes include one or more pilot modes where fuel is not mixed with air prior to combustion, and one or more premix modes where fuel is highly mixed with air prior to combustion.

Abstract: A hybrid electric vehicle, such as a bus or delivery vehicle, includes batteries and a turbogenerator/motor connected through a double conversion control system. The batteries and the turbogenerator/motor are each connected to a DC bus through bi-directional power converters operating as customized bi-directional switching converters configured, under the control of a power controller, to provide an interface between the DC bus and the batteries and turbogenerator/motor, respectively.

Abstract: A closed loop Rankine bottoming cycle including a heat exchanger coupled to an exhaust port of a first turbogenerator for heating a pressurized refrigerant into a gaseous phase, and a second turbogenerator (e.g., a turbo expander) coupled to the heat exchanger for expanding the gaseous phase so as to create power. Also included is a cooling mechanism coupled to an exhaust of the second turbogenerator for cooling the gaseous phase exhausted by the second turbogenerator into a liquid phase, and a pumping mechanism for pressurizing the liquid phase into the pressurized refrigerant heated by the heat exchanger. A computer program product and method for operating and synchronizing the generator included in the closed loop, so as to optimize the overall system efficiency is also included.

Abstract: One embodiment includes a plurality of equally spaced top foils and corrugated springs with one or more shims underneath the trailing edge of each corrugated spring. The corrugated spring forms an underspring for the top foil. Another embodiment incorporates one or more shims at the outer radius region of the corrugated spring in addition to the shim at the trailing edge of the corrugated spring. The shim under the trailing edge of the corrugated spring results in increased load capacity and stability and a decrease in lift-off speed of the rotating thrust disk. The shims located at the outer radii of the corrugated springs result in increased bearing stiffness at the outer region of the compliant foil thrust bearing where the highest pressure occurs.

Abstract: A turbogenerator having a compressor configured to compress a fuel oxidizer, a combustor connected to an exhaust of the compressor and configured both to receive the fuel oxidizer and a fuel and to combust the fuel and the fuel oxidizer into a combusted gas, a fuel supplier configured to control fuel droplet sizes of the fuel supplied into the combustor to prevent flameout of the turbogenerator, a turbine connected to an exhaust of the combustor and configured to convert heat from the combusted gas into rotational energy, a motor/generator configured to convert the rotational energy into electrical energy, and a common shaft connecting the turbine, the compressor, and the motor/generator. The common shaft is configured to rotate the turbine, the compressor, and the motor/generator.

Abstract: A method of controlling a generator system connected to an electric power system in which the output frequency characteristic of the generator system is measured, a first phase angle and frequency of the measured frequency characteristic is estimated using a first phase locked loop having a first bandwidth, and a second phase angle and frequency of the measured frequency characteristic is estimated using a second phase locked loop having a second bandwidth greater than the first bandwidth. Further, the method calculates a frequency difference between the first and second estimated frequencies, and an angle variation that is proportional to the calculated frequency difference. The estimated second phase angle is then added to the calculated angle variation so as to form an output current phase angle reference, and an output current phase angle of the generator system is controlled to be aligned with the output current phase angle reference.

Abstract: A gas turbine engine includes a rotatable impeller having a plurality of vanes with inlet and outlet ends. A plurality of diffuser channels are spaced apart radially beyond the outlet ends. A movable source of gaseous fuel is positioned adjacent the inlet ends of the vanes. The movable source of gaseous fuel is movable as a function of the rotational speed of the impeller, whereby the flow of gaseous fuel injected from the movable source is ejected from the outlet ends of the vanes into a selected one of the plurality of diffuser channels to facilitate combustion.

Abstract: A crossing spiral compressor or pump having a cylindrical rotor rotating within a cylindrical stator bore. Both the outer surface of the rotor and the bore of the stator include a plurality of spiral fluid flow channels separated by narrow blades, with the spiral fluid flow channels of the stator bore spiraling in the reverse or opposite direction relative to the spiral fluid flow channels of the rotor. The fluid flow channels on the rotor and in the bore have open sides that face the annular gap between the rotor and stator with the channels crossing each other at many locations to facilitate fluid exchange between rotor channels and bore channels.

Abstract: A power control system for a turbogenerator which provides electrical power to one or more pump-jack oil wells. When the induction motor of a pump-jack oil well is powered by three-phase utility power, the speed of the pump-jack shaft varies only slighty over the pumping cycle but the utility power requirements can vary by four times the average pumping power. This power variation makes it impractical to power a pump-jack oil well with a stand-alone turbogenerator controlled by a conventional power control system. This power control system comprises a turbogenerator inverter, a load inverter, and a central process unit which controls the frequency and voltage/current of each inverter.

Abstract: A method and system to automatically restart a permanent magnet turbogenerator/motor when a fatal fault is detected. The automatic restart logic includes time constraints and limitations on the number of iterations, and is useful regardless of whether the permanent magnet turbogenerator/motor is in a grid connect mode or a standalone mode, and regardless of how the fatal fault originates or is detected. Additional control logic is utilized to handle grid transients and over load conditions to prevent a fatal fault from occurring by using time constraints and an iterative process, together with a brake resistor to control DC bus voltage.

Abstract: A power control system for a turbogenerator which provides electrical power to one or more pump-jack oil wells. When the induction motor of a pump-jack oil well is powered by three-phase utility power, the speed of the pump-jack shaft varies only slightly over the pumping cycle but the utility power requirements can vary by four times the average pumping power. This power variation makes it impractical to power a pump-jack oil well with a stand-alone turbogenerator controlled by a conventional power control system. This power control system comprises a turbogenerator inverter, a load inverter, and a central processing unit which controls the frequency and voltage/current of each inverter.

Abstract: A power control system for a turbogenerator which provides electrical power to one or more pump-jack oil wells. When the induction motor of a pump-jack oil well is powered by three-phase utility power, the speed of the pump-jack shaft varies only slightly over the pumping cycle but the utility power requirements can vary by four times the average pumping power. This power variation makes it impractical to power a pump-jack oil well with a stand-alone turbogenerator controlled by a conventional power control system. This power control system comprises a turbogenerator inverter, a load inverter, and a central processing unit which controls the frequency and voltage/current of each inverter.

Abstract: A permanent magnet rotor cooling system and method in which the rotor end cap includes an axially extending bore with a plurality of radially extending holes aligned with holes in the sleeve around the permanent magnet to provide cooling air flow to the air gap between the permanent magnet sleeve and the stator. A second smaller diameter extended bore, with a second plurality of radially extending holes, offset from the first plurality of holes, may also be provided.

Abstract: A multi-injector combustion system in which a brake resistor is utilized to provide a minimum load for the combustor system during idle or low power operation of the permanent magnet turbogenerator/motor and also to absorb power during transients to prevent flame out of the combustor. In addition, during single injector operation, a relighting method and system are provided to relight the combustor and prevent the necessity of a complete shutdown of the system. The method and system includes switching between the multiple injectors to find the most stable injector in single injector operation.

Abstract: A gas turbine engine includes a rotatable impeller having a plurality of vanes with inlet and outlet ends. A plurality of diffuser channels are spaced apart radially beyond the outlet ends. A movable source of gaseous fuel is positioned adjacent the inlet ends of the vanes. The movable source of gaseous fuel is movable as a function of the rotational speed of the impeller, whereby the flow of gaseous fuel injected from the movable source is ejected from the outlet ends of the vanes into a selected one of the plurality of diffuser channels to facilitate combustion.

Abstract: A helical flow compressor/turbine permanent magnet motor/generator in which a pair of journal bearings are disposed on either side of the multiple impellers of the helical flow compressor/turbine of the helical flow compressor/turbine permanent magnet motor/generator.

Abstract: The power meter, required in most utility grid connectged applications to measure load consumption, is utilized to provide a feedback to an associated turbogenerator power controller, providing a control system for peak shaving, load following, reactive power control, reverse flow protection and load analysis for scheduled turbogenerator operation. This control system operates with simple discrete signals for peak shaving operation, to more complex pulse signals for load following, to load profile analysis and scheduled operation based on a microprocessor based serial input from a digital power meter.