Induction Generator Patents (Class 322/47)
  • Patent number: 8847560
    Abstract: A power supply circuit for supplying electrical energy in an aircraft, the circuit including a power supply generator configured to be driven in rotation by the engine of the aircraft to power electrical equipment of the aircraft engine. The power supply generator includes an asynchronous machine connected to an excitation device. The asynchronous machine includes a rotor configured to be driven in rotation by the engine and a stator connected to the electrical equipment. The excitation device is configured to cause a reactive current of flow in the stator.
    Type: Grant
    Filed: November 7, 2011
    Date of Patent: September 30, 2014
    Assignee: Hispano-Suiza
    Inventor: Eric De Wergifosse
  • Publication number: 20140253055
    Abstract: The present techniques include methods and systems for operating converter to maintain a lifespan of the converter. In some embodiments, the operating frequency of the converter may be increased such that stress may be reduced on the bond wires of the converter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the converter operating in a maximum power point tracking (MPPT) mode and determining whether the MPPT operation results in aging the converter to a point which reduces the converter lifespan below a desired lifespan. If the MPPT operation reduces the converter lifespan below the desired lifespan, the frequency of the converter may be increased such that the converter may be controlled to operate at a percentage of MPPT. Thus, in some embodiments, power output may be optimized with respect to maintaining a desired lifespan of the converter.
    Type: Application
    Filed: May 22, 2014
    Publication date: September 11, 2014
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Lixiang Wei, Russel J. Kerkman, Richard A. Lukaszewski, Haihui Lu, Zhenhuan Yuan
  • Publication number: 20140247021
    Abstract: The present subject matter is directed to systems and methods for controlling variable speed generators, particularly converters associated with doubly-fed induction generators (DFIG) to permit use of harmonic attenuating filters that are generally smaller and less costly than previous similar filters. The subject matter provides for controlling line-side and rotor-side converters in such a manner that the frequencies generated by the converters are interleaved in a manner that the filters see a higher switching frequency and thus may be designed based on those higher frequencies, thereby requiring smaller and less expensive components.
    Type: Application
    Filed: March 4, 2013
    Publication date: September 4, 2014
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Robert Gregory Wagoner, David Smith
  • Publication number: 20140159677
    Abstract: The present subject matter is directed to systems and methods for improving reliability of dual bridge doubly fed induction generators (DFIGs) by reducing the number of required components in the converters associated with such DFIGs. A converter is constructed using a pair of current conducting bridges wherein one of the current conducting bridges is controlled and the second is not controlled. The uncontrolled bridge may correspond to a pair of diodes while the controlled bridge may correspond to a pair of transistors, in particular, a pair of IGBT transistors.
    Type: Application
    Filed: December 7, 2012
    Publication date: June 12, 2014
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Robert Gregory Wagoner, David Smith
  • Patent number: 8698461
    Abstract: The invention relates to a method to control power output of a doubly-fed induction machine to a grid including the steps of measuring grid voltage and grid current in a three phase coordinate system, transforming grid voltage and grid current into a stator frame coordinate system, decomposing the grid voltage and grid current in the stator frame coordinate system in a positive sequence system and in a negative sequence system, calculating active and reactive power in the positive and negative sequence system, and controlling active and reactive power in the positive and negative sequence system.
    Type: Grant
    Filed: September 11, 2008
    Date of Patent: April 15, 2014
    Assignee: Woodward Kempen GmbH
    Inventors: Stephan Engelhardt, Joerg Kretschmann
  • Publication number: 20130234679
    Abstract: A power supply circuit for supplying electrical energy in an aircraft, the circuit including a power supply generator configured to be driven in rotation by the engine of the aircraft to power electrical equipment of the aircraft engine. The power supply generator includes an asynchronous machine connected to an excitation device. The asynchronous machine includes a rotor configured to be driven in rotation by the engine and a stator connected to the electrical equipment. The excitation device is configured to cause a reactive current of flow in the stator.
    Type: Application
    Filed: November 7, 2011
    Publication date: September 12, 2013
    Applicant: HISPANO-SUIZA
    Inventor: Eric De Wergifosse
  • Patent number: 8035357
    Abstract: A permanent magnet machine (PMM) has a kinetic portion electrically coupled to a power conversion portion. Motive power is provided to the kinetic portion by a torque applied to a motive shaft coupled to a prime mover, such as an aircraft engine or an automobile engine. A sensor is effective to detect a fault condition in the kinetic portion. When a fault is detected, the sensor applies a voltage to a winding within the kinetic portion generating an opposing directional counter torque to the motive shaft. A combination of the torque and counter torque exceeds a fracture yield strength of the motive shaft. The fault condition is then rendered safe while the prime mover may continue normal operation.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: October 11, 2011
    Assignee: Astronics Advanced Electronic Systems Corp.
    Inventor: Stanley C. Patterson
  • Patent number: 7892304
    Abstract: An apparatus for producing hydrogen having compressor motor speed control. The apparatus includes a hydrogen generator for producing a product comprising hydrogen and a compression unit for compressing the product. The hydrogen generator can include a fuel processor having an oxidizer and a reformer. The compression unit has an induction motor and means for regulating the speed of the motor. The means for regulating the speed of the motor can include a variable frequency drive or soft start device having a plurality of switches and an adjustable ramp timer. A downstream unit including one or more of a purification unit, a second compression unit, and a storage unit is disposed downstream of the compression unit. A method for producing hydrogen is provided that includes generating a product comprising hydrogen in a hydrogen generator, compressing the product in a compression unit having an induction motor and regulating the speed of the motor in response to transient operations of the hydrogen generator.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: February 22, 2011
    Assignee: Texaco Inc.
    Inventor: Masoud Hajiaghajani
  • Patent number: 7888915
    Abstract: A system includes an induction generator controller configured to operate an induction generator via a converter. The induction generator controller includes a diagnostic mode configured to instruct the converter to send an input signal to a rotor of the induction generator, receive an output signal from the rotor and a stator of the induction generator, and identify winding faults within the rotor and/or the stator based on the output signals.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: February 15, 2011
    Assignee: General Electric Company
    Inventors: Haiqi Zhao, Qimou Xiong, Yanhang Li
  • Publication number: 20100207479
    Abstract: An electric power generator for generating a substantially constant frequency output from a varying mechanical speed input such as from a wind or water turbine, comprises a three-phase induction machine in which at least one stator winding is magnetically and electrically decoupled from at least one other stator winding which is arranged to be connected to an external load, and a power source is arranged to excite said at least one stator winding with an AC current at a desired output frequency. The power generator can be directly connected to the mains grid without requiring a power electronics rectifier and inverter stage to convert the generator output to constant frequency AC.
    Type: Application
    Filed: July 25, 2008
    Publication date: August 19, 2010
    Inventor: Udaya Madawala
  • Publication number: 20100164428
    Abstract: A method and system for an engine starter/generator is provided. The starter/generator system includes a three phase squirrel cage induction machine, a three phase inverter/converter electrically coupled to the three phase squirrel cage induction machine. The starter/generator system also includes a bidirectional DC-DC converter electrically coupled to the three phase inverter/converter, and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode. During the start mode, logic in the digital control board configures the starter/generator system into a combination of an induction motor, a three phase DC-AC inverter, and a DC-DC boost converter, and during a generate mode, the logic in the digital control board configures the starter/generator system into a combination of an induction generator, a three phase AC-DC converter, and a DC-DC buck converter.
    Type: Application
    Filed: December 31, 2008
    Publication date: July 1, 2010
    Inventors: Longya Xu, David Dimitri Karipides, Mohamed Abbas, Hao Huang
  • Patent number: 7667439
    Abstract: A power converter arrangement for connecting an induction generator to an electric power network comprises a first path provided for transferring electric power from the induction generator to the electric power network during a first operation condition, and a second path provided for transferring electric power from the induction generator to the electric power network during a second operation condition, where the first path includes an AC-AC converter and the second path includes a switch. A capacitor arrangement is interconnected between the induction generator and the first and second paths and a first AC reactor device is interconnected between the capacitor arrangement and the first and second paths, where the capacitor arrangement is provided for compensating for a magnetization current of the induction generator.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: February 23, 2010
    Assignee: ABB Research Ltd.
    Inventors: Lars Gertmar, Erik Koldby, Hans C. Christensen, Jouko Niiranen, Leif-Erik Wraae, H{dot over (a)}kan Korske, legal representative
  • Patent number: 7633176
    Abstract: An electrical power generator is provided which is a direct drive induction generator capable of being directly connected to the power grid for the creation of electrical power. The rotor of the induction generator is located along the outside periphery of the stator and the stator may be provided with a plurality of poles. The number of poles provided on the stator may be adjusted to obtain an optimal rotational speed required to generate power. Using this arrangement, a low cost, efficient, reliable and easy to build wind generator may be provided.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: December 15, 2009
    Assignee: Earth Turbines, Inc.
    Inventor: David C. Blittersdorf
  • Patent number: 7615880
    Abstract: A wind turbine generator system can regulate the rotational velocity of the wind turbine within an operation range even when the wind velocity suddenly changes and can perform continuous operation of the wind turbine. The wind turbine generator system includes a generator connected to the shaft of the wind turbine and a converter connected to the generator. When the rotational velocity of the wind turbine is within a predetermined range, power outputted from the generator is controlled so as to follow the instruction concerning the generator output given from the wind turbine to the converter. When the rotational velocity of the wind turbine is out of the predetermined range, the power outputted from the generator is controlled without following the instruction concerning generator output given from the wind turbine to the converter.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: November 10, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Akira Kikuchi, Masaya Ichinose, Motoo Futami, Mitsugu Matsutake, Kouichi Miyazaki
  • Patent number: 7602153
    Abstract: A device for providing a regulated, limited generator excitation current to a generator to acquire a regulated output voltage of the generator, the device including a combiner for weighted combining a first system deviation on the basis of a setpoint voltage and of the regulated output voltage, and a second system deviation on the basis of a predefined current value and of the regulated generator excitation current so as to acquire a combination signal based on the combination of the first system deviation and the second system deviation, a provider for providing a actuating variable on the basis of the combination signal and a regulation specification, and a provider for providing the regulated, limited generator excitation current to the generator on the basis of the actuating variable, so that the regulated output voltage may be provided by the generator.
    Type: Grant
    Filed: November 29, 2006
    Date of Patent: October 13, 2009
    Assignee: Infineon Technologies Austria AG
    Inventor: Manfred Steiner
  • Publication number: 20090251112
    Abstract: A permanent magnet (PM) electric generator with directly controllable field excitation control comprises: a drive shaft; a PM rotor assembly with multiple PMs arranged around an outer axial periphery of the rotor assembly; a stator assembly comprising a ferromagnetic stator yoke, multiple ferromagnetic stator teeth mounted to the stator yoke with distal ends proximate the outer axial periphery of the rotor assembly separated by an air gap and multiple stator coils mounted between the stator teeth; multiple saturable ferromagnetic shunts, each shunt coupling adjacent distal ends of the stator teeth to shunt air gap magnetic flux ?g generated by the PMs across the air gap through the distal ends of the stator teeth; and multiple saturation control coils, each saturation control coil wrapped about a saturable region of an associated one of the shunts; wherein application of a control current Ic to the control coils at least partially magnetically saturates the shunts to reduce shunting of air gap magnetic flux ?
    Type: Application
    Filed: April 2, 2008
    Publication date: October 8, 2009
    Applicant: HAMILTON SUNDSTRAND CORPORATION
    Inventors: Jacek F. Gieras, Gregory I. Rozman
  • Patent number: 7595612
    Abstract: A device and method for controlling the output of a wide speed range high reactance permanent magnet machine based PGS is provided. The windings of a permanent magnet machine are coupled to a three-phase diode bridge. A transistor is used for temporarily short-circuiting said diode bridge. A capacitor smoothes the voltage at a voltage detection point. A control unit generates a signal that switches the transistor in response to a voltage detected at the voltage detection point. The control unit signal modifies the duty cycle of the switching of the transistor in response to variations in the speed of the power generator to maintain a desired voltage at the voltage detection point.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: September 29, 2009
    Assignee: Honeywell International Inc.
    Inventors: Evgeni Ganev, Andrew R. Druzsba, Addy Fouad Alkhatib
  • Patent number: 7486053
    Abstract: An electrical power generator includes a controller for making a full power capacity of the generator available for consumption by at least one intelligent load coupled to an output of the generator. The controller obtains data from which both a present output power of the generator and a power capacity of the generator can be determined. The controller then provides the intelligent load with data indicative of both the present output power and the power capacity of the generator for use by the load in controlling its power consumption.
    Type: Grant
    Filed: June 17, 2005
    Date of Patent: February 3, 2009
    Assignee: Hamilton Sundstrand Corporation
    Inventors: Wei Wei Qi, Michael Rubbo, Richard Wainwright
  • Publication number: 20080164851
    Abstract: Conventional electric power generation system employ a solid state electronically controlled IM that may be capable of self-start motoring and power generation, but, when the DC bus voltage collapses upon a failure, an additional external source of DC voltage is not available for IM excitation. The present invention provides an internal bus that does not collapse when the main DC bus is shorted. This internal or auxiliary bus may be used to excite the IM to provide generation function. The power generation systems of the present invention may play a significant role in the modern aerospace and military industries.
    Type: Application
    Filed: January 9, 2007
    Publication date: July 10, 2008
    Applicant: HONEYWELL INTERNATIONAL INC.
    Inventors: Evgeni Ganev, Leroy A. Fizer
  • Patent number: 7355367
    Abstract: A system and method is provided for generating AC power using a synchronous reluctance machine (12) or a salient-pole synchronous machine (102) and a power converter (110). The present invention can be used to achieve power production for a synchronous reluctance machine (12), or can be used to achieve AC power from a traditional salient-pole synchronous machine/starter (102) without dependence upon a rotor current which is subject to failure. In the power generation system, the control system and method can include a power converter (110), controlled by a voltage command and at least one of a measured AC bus (125) current and voltage, and a DC link (120) voltage, for use with a synchronous reluctance machine (102) and a prime mover (116), such that movement of the rotor of the synchronous reluctance machine (102) can be used to produce at least partial AC power generation on the AC bus (125).
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: April 8, 2008
    Assignee: Honeywell International, Inc.
    Inventors: Bulent Sarlioglu, Colin E. Huggett
  • Patent number: 7330016
    Abstract: A method for enhancing the operation of an electrical power supply includes selecting a prime mover having a chosen power rating. An induction motor having a first power rating at a rated speed and a second power rating at an overspeed is chosen. The overspeed may be at least about 10%, or at least about 25%, 50%, 75%, 10 to 300%, 25 to 300%, or 50 to 100%, greater than the rated speed. The induction motor may be chosen so that the second power rating is substantially the same as the chosen power rating of the prime mover. The induction motor is driven by the prime mover so that the induction motor acts as an induction generator. The system may also comprise a control module to monitor the performance of the power supply and to provide a throttle control signal in response to a control parameter signal. A circuit input of a phase shift circuit may be connected to a generator output. A converter input of an AC to DC converter may be connected to a circuit output of the phase shift circuit.
    Type: Grant
    Filed: October 19, 2004
    Date of Patent: February 12, 2008
    Inventor: Bruce H. Colley
  • Patent number: 7309974
    Abstract: A system and method is provided for generating AC power using a synchronous reluctance machine (12) or a salient-pole synchronous machine (102) and a power converter (110). The present invention can be used to achieve power production for a synchronous reluctance machine (12), or can be used to achieve AC power from a traditional salient-pole synchronous machine/starter (102) without dependence upon a rotor current which is subject to failure. In the power generation system, the control system and method can include a power converter (110), controlled by a voltage command and at least one of a measured AC bus (125) current and voltage, and a DC link (120) voltage, for use with a synchronous reluctance machine (102) and a prime mover (116), such that movement of the rotor of the synchronous reluctance machine (102) can be used to produce at least partial AC power generation on the AC bus (125).
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: December 18, 2007
    Assignee: Honeywell International, Inc.
    Inventors: Bulent Sarlioglu, Colin E. Huggett
  • Patent number: 7215098
    Abstract: The invention provides an electrical generating system comprising an AC electrical generator (G) having an output, and a capacitor arrangement (Ca) provided at the output of the generator and arranged so as to offset a drop of voltage from no-load to full-load occurring at the output of the generator. As described, the generator (G) is a permanent-magnet generator having a plurality of terminals and associated output lines, and the capacitor arrangement comprises a respective capacitor (Ca) connected in series in each of the output lines, with the value of the capacitance of each capacitor being selected such that a drop of voltage from no-load to full-load occurring at the associated generator terminal is substantially offset at an output terminal of each said capacitor.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: May 8, 2007
    Assignee: Bowman Power Systems Ltd.
    Inventors: Martyn Harris, Matthew James Reed
  • Patent number: 7095192
    Abstract: An automotive generator/motor is driven by a battery via an inverter. Resistance 2Ra0 is expressed by 2Ra0=Vmax/?{square root over (3)} Iamax, where Vmax is a maximum voltage applicable across any two terminals from the inverter and Iamax is a maximum current which must be fed from the inverter into each of the terminals when the maximum voltage Vmax is applied for maximizing torque produced by the automotive generator/motor at a power factor of 1 under voltage saturation conditions, and the armature winding is configured such that resistance 2Ra across any two terminals satisfies a relationship expressed by 0.8Ra0?2Ra?3.8Ra0.
    Type: Grant
    Filed: December 19, 2005
    Date of Patent: August 22, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Fujita, Haruyuki Kometani
  • Patent number: 7095131
    Abstract: A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional, integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: August 22, 2006
    Assignee: General Electric Company
    Inventors: Amir S. Mikhail, Craig L. Christenson, Kevin L. Cousineau, William L. Erdman, William E. Holley
  • Patent number: 6977487
    Abstract: A vehicular alternator failure determination apparatus is capable of making a failure determination accurately. The apparatus includes a maximum voltage detection part (1) for detecting a maximum voltage of an alternator commutating device which commutates an AC output of the alternator driven by an engine, a minimum voltage detection part (2) for detecting a minimum voltage of the alternator commutating device, a voltage difference calculation part (3) for detecting a difference voltage from outputs of the maximum and minimum voltage detection parts, and a failure determination part (4) which determines that the alternator is in a failure state, when an output of the voltage difference calculation part is equal to or greater than a prescribed voltage.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: December 20, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroshi Fujioka, Takanori Matsunaga, Takashi Maeda, Toshinori Matsui
  • Patent number: 6933705
    Abstract: A method and apparatus of stator voltage control for an induction generator. Each phase of the induction generator stator is connected through a secondary coil of a transformer to a utility grid. A stator voltage control circuit is connected in parallel with a primary coil of the transformer. The stator voltage control circuit consists of an on/off switch device connected to a full wave rectifier comprised of four silicon diodes. A single pulse width modulation (PWM) control is utilized to control the on/off switch devices of each phase of the induction generator stator.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: August 23, 2005
    Assignee: Chipper Windpower Technology, Inc.
    Inventor: Lawrence H. Howes
  • Patent number: 6930471
    Abstract: A power generation plant comprising a power generating unit that includes at least one first generator, such as an induction generator, coupled to at least one synchronous generator having a rotor with a superconducting (SC) coil. The induction generator and the SC synchronous generator are coupled so that the SC synchronous generator supplies the induction generator with reactive power. Sufficient reactive power is preferably generated by the SC synchronous generator to meet the demand of the induction generator for VARs, as well as permit the induction generator to have a relatively large airgap.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: August 16, 2005
    Assignee: General Electric Company
    Inventors: Kiruba Sivasubramaniam, Yu Wang, Konrad Weeber
  • Publication number: 20040257050
    Abstract: The invention relates to a method for constant-current generation by means of a rotational energy source, a generator and a control circuit connected to the generator. Mechanical rotational energy is generated by the energy source and the mechanical rotational energy is transmitted to the generator rotor. The magnetic field distribution produced in the generator is controlled by the control circuit that controls the current distribution in the generator between load current and generator current by feedback control by generating an opposing magnetic field. The power uptake and the current output are adapted without losses and the alternating current generated by the generator is transferred to an averaging direct-current circuit. The invention further relates to a suitable device for carrying out the inventive method.
    Type: Application
    Filed: July 26, 2004
    Publication date: December 23, 2004
    Inventor: Peter Kilian Zeller
  • Patent number: 6815934
    Abstract: An induction generator power supply comprises a prime mover, an induction generator operably connected to the prime mover and having a generator output, and a phase shift circuit, having a circuit input and a circuit output, the circuit input connected to the generator output. The power supply also comprises an AC to DC converter, having a converter input and a converter output, the converter input connected to the circuit output, and an energy reservoir having a reservoir input connected to the converter output.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: November 9, 2004
    Assignee: Haynes Beffel & Wolfeld LLP
    Inventor: Bruce H. Colley
  • Patent number: 6788031
    Abstract: An induction generator having one or more energy windings and one or more auxiliary windings where the auxiliary windings have fixed and switched capacitors which are used to control the induction generator output under variable load conditions. The auxiliary windings are electrically and magnetically isolated from the energy windings. The fixed capacitors are used under minimum load condition and the switched capacitors added in response to controls signals. The control signals are determined by analyzing the load voltage and current and the voltage across the particular capacitor being added. The induction generator is included in systems where the generator is rotationally driven by an engine and which couples the energy windings to a power grid and/or to a variable load. The engine may also employ a controller that receives the load current and voltage signals to determine engine speed.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: September 7, 2004
    Inventor: Larry Stuart Pendell
  • Patent number: 6707279
    Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a minimal number of current sensors and controlling at least one of a machine flux, an output voltage and generator torque, based on the stator or rotor flux magnitude and position. This method comprises measuring a plurality of current amounts; transforming them into a two phase reference system; measuring a DC voltage; measuring voltage amounts in the generator; transforming the plurality of voltage amounts into the two phase reference system; calculating a flux in the generator; comparing the calculated flux magnitude with a desired flux; determining a d-axis voltage; determining a desired torque amount; comparing the desired torque amount with an estimated torque amount; determining a q-axis voltage; and transforming the d-axis voltage and the q-axis voltage to stationary reference frame n-phase voltages using the position of the flux.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: March 16, 2004
    Assignee: Ford Global Technologies, Inc.
    Inventors: Victor R. Stefanovic, John Michael Miller
  • Patent number: 6486639
    Abstract: The generator includes an asynchronous machine with a wound rotor driven mechanically and a stator connected to the network. The rotor is excited by a constant DC voltage source via an inverter controlled by a pulse width modulation control circuit. In accordance with the invention, the following are generated: a stator frequency set point, a rotor frequency set point which is a function of the stator frequency set point and the rotation speed of the machine, an rms stator voltage set point, an error signal which is a function of the difference between the rms stator voltage set point and the actual rms stator voltage. A rotor voltage set point is imposed on the control circuit which is a function of the error signal and the rotor frequency set point.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: November 26, 2002
    Assignee: Dassault Aviation
    Inventors: Christophe Montret, Christian Marie Pierre Jacquet-Francillon
  • Patent number: 6417650
    Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a plurality of flux sensing coils and controlling at least one of a machine flux and an output voltage based on the stator or rotor flux magnitude and position. One embodiment of the invention only uses flux sensing coils without requiring current sensors or position sensors.
    Type: Grant
    Filed: December 13, 2000
    Date of Patent: July 9, 2002
    Assignee: Ford Global Technologies Inc.
    Inventors: Victor R. Stefanovic, John Michael Miller
  • Patent number: 6310417
    Abstract: An uncluttered secondary induction machine (100) includes an uncluttered rotating transformer (66) which is mounted on the same shaft as the rotor (73) of the induction machine. Current in the rotor (73) is electrically connected to current in the rotor winding (67) of the transformer, which is not electrically connected to, but is magnetically coupled to, a stator secondary winding (40). The stator secondary winding (40) is alternately connected to an effective resistance (41), an AC source inverter (42) or a magnetic switch (43) to provide a cost effective slip-energy-controlled, adjustable speed, induction motor that operates over a wide speed range from below synchronous speed to above synchronous speed based on the AC line frequency fed to the stator.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: October 30, 2001
    Assignee: Lockheed Martin Energy Research Corporation
    Inventor: John S. Hsu
  • Patent number: 6163137
    Abstract: A rotary induction machine in which operating characteristics of the machine are controlled by adding impedance elements to the rotor windings in which the impedance elements are stationary and connected to the rotor windings by a rotary transformer.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: December 19, 2000
    Assignee: Heller-DeJulio Corporation
    Inventors: Alan K. Wallace, James A. Oliver
  • Patent number: 6020725
    Abstract: An asynchronous alternating current motor/generator having an armature winding which includes interspersed energy coils and reflux coils which are electrically and inductively isolated from each other, but which are paramutually inductively coupled through the rotor. Each reflux coil is positioned at 90 electrical degrees to the adjacent energy coil and is tuned to minimize the inductive reactance of the motor/generator.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: February 1, 2000
    Assignee: Lifeline Enterprises L.L.C.
    Inventor: Gary Dean Roberts
  • Patent number: 5986438
    Abstract: A rotary induction machine having wound primary and secondary windings with resistive means connected in series with secondary windings and inductive reactive means connected across said resistive means, with the inductive reactance means and resistive means selected to provide an effective resistance which controls the current in the generator secondary windings, whereby the generator rated current is reached at the highest slip for the range of desired power output.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: November 16, 1999
    Assignee: Heller-DeJulio Corporation
    Inventors: Alan K. Wallace, James A. Oliver
  • Patent number: 5929612
    Abstract: In an induction generator, an additional set of stator windings is provided, separate from and secondary to the main stator windings upon which the generator's output voltage is generated and supplied to the load. This separate stator winding is provided for the purpose of supplying the generator with the reactive electrical power it needs to maintain the rotating stator field and supplying any reactive power needed by the load. Thus, there is no need to use a capacitor assembly, for supplying the reactive power needed by the generator. Currents are injected into this separate winding in such a way that only reactive power is supplied to the generator. Specifically, a power measuring circuit measures the power in the additional set of stator windings, and a power error signal is formed by algebraically adding the outputs of the power measuring circuit.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: July 27, 1999
    Assignee: Satcon Technology Corporation
    Inventors: David B. Eisenhaure, James L. Kirtley, Jr., Geoffrey B. Lansberry, Kevin J. Donegan, Gita P. Rao
  • Patent number: 5777459
    Abstract: The invention is an induction electrical power generation system for generating alternating current varying within a frequency range; the system includes an induction electrical generator (52) for generating the alternating current having a rotor and a stator, the stator having at least one phase winding for outputting the generated alternating current and a plurality of poles with at least two different numbers of poles within the plurality of poles being selected to generate the alternating current, an exciter winding wound on the stator which is driven by AC excitation which varies in frequency during generation of the alternating current and the rotor operating with slip during the generation of the alternating current; a variable speed drive coupled to the rotor for driving the rotor in a speed range during generation of the alternating current; an exciter generator (54) coupled to the exciter winding for generating the variable frequency AC excitation; a speed sensor (56) for producing a signal which is
    Type: Grant
    Filed: November 18, 1996
    Date of Patent: July 7, 1998
    Assignee: Sundstrand Corporation
    Inventors: Madan Bansal, Gregory I. Rozman, Pierre Thollot
  • Patent number: 5587647
    Abstract: An electric power starter generator system comprises a synchronous generator and an induction motor/generator mutually coupled to a shaft being driven to an external prime mover. The synchronous generator and the induction motor/generator are driven by the shaft at the same speed. The system includes a rectifier/inverter having ac terminals coupled to the output of the induction motor/generator, and dc terminals coupled to a dc bus. This rectifier/inverter allows bi-directional power flow to effectuate both power generation as well as electric start of the prime mover. The synchronous generator is excited by a commonly driven permanent magnet generator and a modulated exciter field control. The induction motor/generator is self-exciting through the rectifier/inverter once a voltage is established on the dc bus. The establishment of this voltage may be accomplished by a battery, or by connection of the synchronous generator's output to the input of the rectifier/inverter through a poly-phase contactor.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: December 24, 1996
    Assignee: Sundstrand Corporation
    Inventors: Madan L. Bansal, Jayant G. Vaidya
  • Patent number: 5550457
    Abstract: An electric power generating device including an induction type electric rotating machine rotating in interlock with an engine comprises an inverter connected at the AC side to and end of an armature winding and at the DC side to an electric power storing device, a detecting means for detecting the quantity of state related to the electric power generating voltage of the induction type electric rotating machine excluding the measured RPM of the induction type electric rotating machine but including the electric power storing voltage of the electric power storing device, and an electric power generation controlling means for maintaining the electric power storing voltage within the preset range by controlling the frequency of the controlling voltage of the inverter based on the quantity of state related to the electric power generating voltage.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: August 27, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Shin Kusase, Kenzo Mitani, Atsushi Umeda, Hirohide Sato
  • Patent number: 5525894
    Abstract: A rotary induction generator having a stator with stator windings defining a three-phase stator and a rotor mounted for rotation therein, and having wound thereon three rotor windings defining a three-phase rotor and having resistive-reactive means connected to said secondary windings to increase the efficiency of said generator and limit the power output to the capacity of the generator over a wide range of speeds.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: June 11, 1996
    Assignee: Heller-DeJulio Corporation
    Inventor: Samuel Heller
  • Patent number: 5283470
    Abstract: A motor vehicle drive system includes a brushless motor driven by a battery and directly coupled to the vehicle wheels for providing primary motive power. During braking, the motor acts as a generator for recharging the battery. Preferably the recharging current is first allowed to build up by shunting the motor so that the regeneration may occur at both high and low speeds. The regenerative current period may be varied with the speed of the vehicle.
    Type: Grant
    Filed: July 21, 1992
    Date of Patent: February 1, 1994
    Assignee: Lauzun Corporation
    Inventors: John W. B. Hadley, Qianyi Jiang
  • Patent number: 5239251
    Abstract: An AC variable speed drive (VSD) system having a brushless doubly-fed motor receives power from an electric power grid at a system frequency of the grid and drives a mechanical load. The motor has a rotor with rotor windings and a stator with stator windings comprising first and second polyphase stator systems. The first stator system receives power from the grid at the system frequency. A sensor senses a parameter of the received power by the drive and produces a corresponding power sensor signal. A VSD controller receives and processes the power sensor signal and a reference signal which has been established according to a desired motor operation strategy, and generates therefrom a controller signal. A converter, such as a power electronic converter, receives and converts power from a converter powThis invention was made with government support under Grant No. 79-85BP24332, awarded by the Bonneville Power Administration. The United States government has certain rights in this invention.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: August 24, 1993
    Assignee: The State of Oregon Acting by and through the State Board of Higher Education on Behalf of Oregon State University
    Inventor: Hian K. Lauw
  • Patent number: 5194757
    Abstract: Each of at least two asynchronous generators connected to a common electrical load for uninterruptibility of the power supply is driven by a corresponding one of at least two drives in such a way that when any one of the generators is driven above synchronous speed by a slip fraction while its stator is electrically excited, its shaft mechanical power is converted to electrical output power at its output terminal. A control circuit is connected to the load, coupled to the output terminals of the generators and connected to the input terminals of the generators and provides an excitation voltage and controls the phase of the excitation voltage of each of the generators with respect to the load voltage. This controls the slip fraction of each of the generators loosely whereby load current from any source is completely controlled.
    Type: Grant
    Filed: November 20, 1990
    Date of Patent: March 16, 1993
    Assignee: Grumman Aerospace Corporation
    Inventor: Max M. Wertheim
  • Patent number: 5081368
    Abstract: An uninterruptible power source includes an induction motor/generator assembly and a continuously on line variable speed drive connected to inductively accelerate the motor/generator assembly to near rated speed. When the motor/generator assembly reaches rated speed, the motor/generator is switched to synchronous operation, while still under control of the variable speed drive. The variable speed drive includes slip compensation to maintain the motor at rated speed. The variable speed drive operates in response to a utility power signal and to a standby power signal. When the utility power signal fails, operation of the drive is maintained, without interruption, by the standby power.
    Type: Grant
    Filed: January 11, 1990
    Date of Patent: January 14, 1992
    Assignee: Atlas Energy Systems, Inc.
    Inventor: Geoffrey West
  • Patent number: 5053635
    Abstract: An uninterruptible power source is disclosed and claimed which includes a synchronous motor/generator assembly and a continuously on line variable speed drive connected to inductively accelerate the motor/generator assembly to near synchronous speed. When the motor/generator assembly reaches near synchronous speed, the motor/generator is switched to synchronous operation, while still under control of the variable speed drive. The variable speed drive is connected to maintain synchronicity with the motor/generator during acceleration. Resultantly, when switchover to synchronous operation occurs, no synchronization of the motor/generator to the variable speed drive is required. The variable speed drive operates in response to a utility power signal and to a standby power signal. When the utility power signal fails, operation of the drive is maintained, without interruption, by the standby power.
    Type: Grant
    Filed: April 28, 1989
    Date of Patent: October 1, 1991
    Assignee: Atlas Energy Systems, Inc.
    Inventor: Geoffrey West
  • Patent number: 5039933
    Abstract: An induction generator is disclosed wherein both the stator and rotor windings are utilized to generate power with the three phase winding of the stator and rotor each connected in parallel with a delta connected capacitive network connected therebetween. The electrical output may thus be increased by a factor of four over a conventional generator of the same size.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: August 13, 1991
    Assignee: John Dong
    Inventor: Jilan Dong
  • Patent number: 5029288
    Abstract: A method and apparatus for operating a variable speed power generation system in which the generated output of an induction generator is adjusted by controlling current in the secondary side of the induction generator. Rotation speeds of the induction generator coupled to a prime mover are detected, a secondary current command for controlling a difference between a detected rotation speed and a speed command to be zero is generated, and current in the secondary side of the induction generator is controlled on the basis of the secondary current command.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: July 2, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Yuzuru Kubota, Toshiaki Okuyama