Frequency Responsive Devices Or Networks Patents (Class 322/32)
  • Patent number: 10342598
    Abstract: An electrosurgical system is disclosed including an energy source and a plurality of electrodes. Each of the plurality of electrodes is coupled to the energy source and each of the plurality of electrodes is positionable for electrical contact with a target tissue. The energy source is configured to deliver, via the plurality of electrodes, a plurality of pulses of a biphasic radio frequency (RF) waveform to the target tissue. The biphasic RF waveform operates at a fundamental frequency greater than that which electrically stimulates muscular cells. The plurality of pulses induce non-thermal cell death in the target tissue without a measurable stimulation in muscular tissue exposed to the biphasic RF waveform.
    Type: Grant
    Filed: August 4, 2017
    Date of Patent: July 9, 2019
    Assignee: Ethicon LLC
    Inventors: Gary L. Long, Gregory J. Bakos, David N. Plescia
  • Patent number: 10224804
    Abstract: A driving circuit includes a power switch driver and a plurality of current-limiting circuits. The power switch driver is configured to output a driving signal according to a switching signal. Each of the current-limiting circuits has an input terminal electrically coupled to a corresponding one of output terminals of the power switch driver respectively. Output terminals of the current-limiting circuits are electrically coupled to a control terminal of a power switch. The power switch driver is configured to selectively output the driving signal to one of a plurality of output terminals according to a load state of the power switch, such that the driving signal is outputted to the control terminal of the power switch via one of the current-limiting circuits.
    Type: Grant
    Filed: March 12, 2018
    Date of Patent: March 5, 2019
    Assignee: DELTA ELECTRONICS, INC.
    Inventors: Lei-Chung Hsing, Kuo-Ying Liu
  • Patent number: 9895186
    Abstract: An electrosurgical generator includes primary and test sources. The primary source supplies a primary signal and the test source supplies a test signal. The electrosurgical generator includes an output circuit and an abnormality detection circuit. The output circuit is electrically coupled to the primary and test sources. The output circuit receives the primary and test signals from the primary and test sources, respectively. The output circuit is electrically coupled to a load to supply the primary signal thereto. The abnormality detection circuit is electrically coupled to the output circuit to detect an abnormality therein as a function of the test signal. The abnormality detection circuit can also determine a location of the abnormality within the output circuit.
    Type: Grant
    Filed: January 3, 2014
    Date of Patent: February 20, 2018
    Assignee: Covidien
    Inventor: James A. Gilbert
  • Patent number: 9788885
    Abstract: An energy source for use with an electrosurgical system is disclosed. In one embodiment, the energy source includes a power supply, one or more capacitors coupled to the power supply, and a switching component coupled to the one or more capacitors. The switching component is configured to output pulses of a biphasic waveform. The pulses are capable of treating undesired tissue by inducing a change in voltage potential across cell membranes of a plurality of cells in the undesired tissue to promote non-thermal cell death in the plurality of cells. The pulses are also capable of treating the undesired tissue with no or minimal muscle contractions in patient tissue within reach of the biphasic waveform during treatment of the undesired tissue.
    Type: Grant
    Filed: February 18, 2016
    Date of Patent: October 17, 2017
    Assignee: Ethicon Endo-Surgery, Inc.
    Inventors: Gary L. Long, Gregory J. Bakos, David N. Plescia
  • Patent number: 9793703
    Abstract: A method for protecting a permanent magnet generator of a wind turbine with a multiphase generator, and n number of isolated converters, the multiphase generator including a rotor carrying permanent magnets and n number of independent multiphase sub-stators comprising a plurality of windings, each converter being connected to an independent multiphase sub-stator and configured to control the plurality of windings of the multiphase sub-stator comprises determining an asymmetrical short circuit current in one of the sub-stators, which generates a first oscillating torque, disconnecting the converter linked to the sub-stator with an asymmetrically short circuited group of windings, and injecting an asymmetrical current with the remaining connected converters, wherein said injected asymmetrical current generates a second oscillating torque that is substantially opposed in phase to the first oscillating torque so that the first oscillating torque is at least partly compensated is disclosed.
    Type: Grant
    Filed: March 21, 2016
    Date of Patent: October 17, 2017
    Assignee: ALSTOM Renewable Technologies Wind B.V.
    Inventor: Julio Cesar Urresty
  • Patent number: 9752941
    Abstract: A pressure sensor and a pressure sensing method are provided. The pressure sensor includes a substrate; a sensor thin film transistor (TFT) disposed on the substrate and including a gate insulating layer, wherein the gate insulating layer includes an organic matrix in which piezoelectric inorganic nano-particles are dispersed; a power unit configured to apply an alternating current (AC) signal to a gate of the sensor TFT; and a pressure sensing unit configured to obtain a remnant polarization value based on a drain current which is generated in response to the AC signal and detected by the sensor TFT, and to sense a pressure based on the remnant polarization value.
    Type: Grant
    Filed: September 5, 2013
    Date of Patent: September 5, 2017
    Assignees: SAMSUNG ELECTRONICS CO., LTD., SUNGKYUNKWAN UNIVERSITY FOUNDATION FOR CORPORATE COLLABORATION
    Inventors: Sang-hun Jeon, Jong-jin Park, Thanh Tien Nguyen, Ji-hyun Bae, Kyung-eun Byun, Nae-eung Lee, Do-il Kim, Quang Trung Tran
  • Patent number: 9735582
    Abstract: A method of controlling reactive power in a power generation system that includes a grid and a cross compound turbine generator system having a first turbine arranged to drive a first generator and a second turbine arranged to drive a second generator includes replacing the first turbine with a motor, the motor coupled to the first generator and operable to drive the first generator. The method also includes decoupling the second turbine and the second generator to allow the second generator to rotate separate from the second turbine, connecting an electrical output of the first generator to the second generator, and powering the motor to drive the first generator and to synchronize the first generator to the grid.
    Type: Grant
    Filed: June 19, 2015
    Date of Patent: August 15, 2017
    Assignee: Electromechanical Engineering Associates, Inc.
    Inventors: Andrew J. Spisak, Alan J. Spisak
  • Patent number: 9621090
    Abstract: A variable speed generator for producing AC electrical power includes an alternator powerable by rotational action to generate a first AC current, and a first rectifier which rectifies the first AC current from the alternator. The generator further includes a main exciter having a first field winding which receives the rectified first AC current, and having a first armature which produces in response a second AC current. The generator further includes a second rectifier which rectifies the second AC current from the first armature. The generator further includes a main generator having a second field winding which receives the rectified second AC current, and having a second armature which produces in response an output AC current. The second field winding is configured to provide a plurality of selectively activatable pole configurations which differ in the number of their poles, such that the frequency of the output AC current can be varied by switching between the pole configurations.
    Type: Grant
    Filed: August 20, 2015
    Date of Patent: April 11, 2017
    Assignee: ROLLS-ROYCE plc
    Inventors: Ellis F H Chong, Andrew Mackay
  • Patent number: 9331611
    Abstract: A method for controlling synchronous switching in a medium voltage inverter is disclosed. The method includes lighting on a first lamp to notify that a switching operation is ready by ascertaining that the medium voltage inverter is in a normal operation, lighting on a second lamp to notify that a switching operation is under way when receiving an input of switching action, and lighting on a third lamp to notify that the switching operation is completed when the switching action is completed.
    Type: Grant
    Filed: December 15, 2014
    Date of Patent: May 3, 2016
    Assignee: LSIS CO., LTD.
    Inventor: Kyungsue Kim
  • Patent number: 9264028
    Abstract: An apparatus includes a signal converter configured to convert a voltage signal into a current signal and an analog digital converter (ADC) configured to convert the current signal to a digital signal. The apparatus also includes a digital processor configured to process the digital signal and generate an output signal that indicates a zero crossing point of the mains voltage signal.
    Type: Grant
    Filed: December 11, 2013
    Date of Patent: February 16, 2016
    Assignee: MARVELL WORLD TRADE LTD.
    Inventor: David Cousinard
  • Publication number: 20140347019
    Abstract: Apparatus for controlling the excitation current of a variable frequency generator (VFG) including means to create a voltage-regulated DC link using PMG power and frequency information, the latter being the image of the VFG mechanical input speed. A step-down voltage-controlled chopper is inserted between the passive rectifier stage and the excitation current control chopper. The control law of this voltage-controlled source is such that when the mechanical input speed of the VFG increases, its output (controlled DC-link voltage) decreases non-linearly, leading to DC link voltage varying from V (engine at idle) to V/2 (engine at take-off speed). The DC voltage becomes inverse-proportional to input mechanical speed.
    Type: Application
    Filed: May 27, 2014
    Publication date: November 27, 2014
    Inventors: Jean-Louis Lando, Pierre Valin-Saunal
  • Patent number: 8860381
    Abstract: Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: October 14, 2014
    Assignee: Sunpower, Inc.
    Inventor: Ezekiel S. Holliday
  • Patent number: 8816605
    Abstract: An adaptive sliding-frequency triggering ignition method for electronic ballast of high pressure gas discharge lamp includes the steps of: measuring an accurate value of free oscillation frequency of the ballast load loop by using a single-chip before sliding-frequency triggering ignition, implementing safe and reliable sliding-frequency triggering ignition after calculating the initial frequency and ending frequency of sliding-frequency triggering ignition according to the accurate value. The method can safely and reliably finish sliding-frequency triggering ignition course, thus improving the parameters such as the quality, life of the high pressure gas discharge lamp electronic ballast.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: August 26, 2014
    Inventor: Zheng He
  • Patent number: 8754615
    Abstract: An approach for converting a synchronous generator to a synchronous condenser is disclosed. In one aspect, a variable frequency driver is used to provide a starting power source to accelerate a synchronous generator decoupled from a turbine to an operational speed to act as a synchronous condenser. In another aspect, the synchronous condenser can be recoupled back to the turbine to form the synchronous generator.
    Type: Grant
    Filed: June 1, 2011
    Date of Patent: June 17, 2014
    Assignee: General Electric Company
    Inventors: James Michael Fogarty, Gary Edward Gottung, David Mark Stuebner
  • Publication number: 20140062425
    Abstract: The present subject matter is directed to systems and methods for interfacing variable speed generators to a power distribution grid. A plurality of doubly-fed induction generators (DFIG) are provided and coupled to a common shaft of a prime mover. Each of the plurality of DFIGs provides an electrical power output having an output frequency based on a rotational speed of the common shaft. A converter coupled to each DFIG provides variable excitation signals to its respective DFIG sufficient to adjust its output frequency to conform to a power grid frequency requirement.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 6, 2014
    Applicant: General Electric Company
    Inventors: Cyrus David Harbourt, Robert Gregory Wagoner, Luis José Garcés Rivera
  • Publication number: 20140015497
    Abstract: Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic.
    Type: Application
    Filed: July 16, 2012
    Publication date: January 16, 2014
    Applicant: SUNPOWER, INC.
    Inventor: Ezekiel S. Holliday
  • Patent number: 8513911
    Abstract: A power converter that interfaces a motor requiring variable voltage/frequency to a supply network providing a nominally fixed voltage/frequency includes a first rectifier/inverter connected to a stator and a second rectifier/inverter. Both rectifier/inverters are interconnected by a dc link and include switching devices. A filter is connected between the second rectifier/inverter and the network. A first controller for the first rectifier/inverter uses a dc link voltage demand signal indicative of a desired dc link voltage to control the switching devices of the first rectifier/inverter. A second controller for the second rectifier/inverter uses a power demand signal indicative of the level of power to be transferred to the dc link from the network through the second rectifier/inverter, and a voltage demand signal indicative of the voltage to be achieved at network terminals of the filter to control the switching devices of the second rectifier/inverter.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: August 20, 2013
    Assignee: Converteam Technology Ltd.
    Inventors: Rodney Jones, Christopher Newton
  • Publication number: 20120306458
    Abstract: An approach for converting a synchronous generator to a synchronous condenser is disclosed. In one aspect, a variable frequency driver is used to provide a starting power source to accelerate a synchronous generator decoupled from a turbine to an operational speed to act as a synchronous condenser. In another aspect, the synchronous condenser can be recoupled back to the turbine to form the synchronous generator.
    Type: Application
    Filed: June 1, 2011
    Publication date: December 6, 2012
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: James Michael Fogarty, John Noel Cunningham, Gary Edward Gottung, David Mark Stuebner
  • Patent number: 8294431
    Abstract: A method of controlling an engine-driven, electrical generator is provided. The generator generates an output voltage at a frequency with the engine running at an operating speed. The method includes the steps of connecting the generator to a load and varying the operating speed of the engine to optimize fuel consumption in response to the load. Thereafter, the frequency of the output voltage is modified to a predetermined level.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: October 23, 2012
    Assignee: Generac Power Systems, Inc.
    Inventors: Graham W. McLean, David Pollock, Francis X. Wedel
  • Patent number: 8134344
    Abstract: A variable frequency generator regulation control circuit and method for controlling open loop gain under changing generator speed conditions employing a high frequency pulse-width modulated signal with a duty cycle that is controlled such that variations in rectified PMG voltage and generator gain over the generator speed range can be compensated for. This signal is modulated by a low frequency pulse-width modulated signal provided by the generator regulator, using a logic gate to produce a combined signal representing an average voltage signal applied to a generator field winding as the generator speed fluctuates.
    Type: Grant
    Filed: July 15, 2008
    Date of Patent: March 13, 2012
    Assignee: Honeywell International, Inc.
    Inventor: David Hodge
  • Patent number: 8080950
    Abstract: A system and method are provided for controlling the speed of a motor driving a load that is electrically connected to a generator driven by an engine, through use of a first control feedback loop configured to control the rotor flux of the motor by controlling the field excitation of the generator, and a second control feedback loop configured to control the speed of the motor by controlling the throttle position of the engine.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: December 20, 2011
    Assignee: Unico, Inc.
    Inventors: Thomas L. Beck, Michael D. Dry, Mark E. Garlow, Michael O. Lucas, Michael A. MacDonald, Ronald G. Peterson
  • Patent number: 8004250
    Abstract: A pyramid electric generator for harvesting the vibrational energies of Earth's atomic oscillators according to the present invention comprises: (1) an antenna/waveguide that is geometrically optimized; (2) a secondary coil wound with an insulated conductor on a nonconductive coil form, the coil being attached electrically to the conducting surface of the antenna/waveguide such that the secondary coil is attached near the point at which the electric field contacts the antenna/waveguide; (3) the antenna/waveguide connected with the secondary coil serving as a quasi-capacitive series element to provide a specific resonant frequency; and (4) a primary coil of a few turns wound around the secondary coil, the secondary coil being positioned coaxially within the primary coil and acting as a resonant step-up transformer winding, inductively coupled with the primary coil. The generator resonantly couples into specific frequencies of Earth's atomic oscillators and extracts electric energy therefrom.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: August 23, 2011
    Inventor: Peter Grandics
  • Publication number: 20110068753
    Abstract: A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency.
    Type: Application
    Filed: November 24, 2010
    Publication date: March 24, 2011
    Applicant: HONEYWELL INTERNATIONAL INC.
    Inventors: MINGZHOU XU, CRISTIAN E. ANGHEL, WAYNE T. PEARSON
  • Publication number: 20110006547
    Abstract: A method of controlling an engine-driven, electrical generator is provided. The generator generates an output voltage at a frequency with the engine running at an operating speed. The method includes the steps of connecting the generator to a load and varying the operating speed of the engine to optimize fuel consumption in response to the load. Thereafter, the frequency of the output voltage is modified to a predetermined level.
    Type: Application
    Filed: July 13, 2009
    Publication date: January 13, 2011
    Inventors: Graham W. McLean, David Pollock, Francis X. Wedel
  • Patent number: 7830127
    Abstract: An electric power generator system or a motor comprising a doubly-fed asynchronous generator or motor comprising a stator and a rotor, a transformer having a first winding and a second winding, the first winding having a first end and a second end; and wherein the stator and the transformer are connectable in series with an electric power distribution grid.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: November 9, 2010
    Assignee: Wind To Power System, S.L.
    Inventors: Jose Manuel Corcelles Pereira, Jose Luis Rodriguez-Amenedo, Santiago Arnaltes-Gómez
  • Publication number: 20100277134
    Abstract: The invention relates to a method for operating a wind energy plant having a double-fed asynchronous machine, at least one inverter and at least one control device, wherein electrical energy is at least partly supplied into a grid via the inverter, the inverter comprises per phase at least one power semi-conductor module with at least two transistor circuits and at least two free-wheeling diodes and the inverter by using the control device is actuated at least at times via a pulse width modulation (PWM).
    Type: Application
    Filed: January 6, 2009
    Publication date: November 4, 2010
    Applicant: WOODWARD SEG GMBH & CO. KG
    Inventors: Stephan Engelhardt, Andrzej Geniusz
  • Patent number: 7501798
    Abstract: A method for the active damping of a drive train in wind energy plant, with the following steps: the actual value of the generator rotational speed is acquired and amplified via an oscillatory delay element, the oscillatory delay element has a predetermined natural oscillation frequency (?E), which is smaller than the smallest natural frequency of the drive train, and a difference between the actual value of the rotational speed and the amplified value for the rotational speed is connected to a controller as actuating variable, which determines a correction moment for a generator control.
    Type: Grant
    Filed: July 11, 2007
    Date of Patent: March 10, 2009
    Assignee: Nordex Energy GmbH
    Inventors: Malte Laubrock, Thomas Paul Woldmann, Soren Bilges
  • Publication number: 20080157724
    Abstract: An electric power generation system is disclosed that provides an AC electric power output with the target waveform period. A sequence of values is established that each represent electric current of the output for a corresponding one of a number of sequential time segments. A processor executes operating logic to process the values for each respective one of the time segments that includes: determining a difference between a first one of the values and the second one of the values for the respective one of the time segments, selecting the second one of the values from the subset of values corresponding to a subset of the time segments, and performing a comparison of the difference to a threshold. Based on this comparison, a transient condition can be identified and/or control of the system can otherwise be facilitated.
    Type: Application
    Filed: April 26, 2007
    Publication date: July 3, 2008
    Inventor: Souren G. Fattal
  • Publication number: 20080143111
    Abstract: A wind power generation system includes: a wind turbine in which at least one blade is mounted on an axis; a generator for generating multiphase alternating current power by rotation of the axis; and a multiphase power conversion device for performing PWM-control for adjustment and output of generated power of the generator. With the configuration, the PWM-control provides for each phase a control paused period in which no overlap occurs. Thus, the pulse density between the control period and the control paused period of other phases is low, thereby generating high and low density in an inter-phase pulse.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 19, 2008
    Inventors: Masaya Ichinose, Shinya Oohara, Motoo Futami, Mitsugu Matsutake
  • Patent number: 7215099
    Abstract: A method in a frequency converter provided with a voltage intermediate circuit in connection with interference in a network (5) to be supplied and a frequency converter (2), which comprises a network converter part (4) and an inverter part (3) and a DC intermediate circuit (7) between them. The method comprises steps of controlling the intermediate circuit voltage at the beginning of network interference by limiting the torque on the inverter side, detecting interference in the network voltage, setting a torque reference to a predetermined value in response to the network interference, detecting network voltage recovery, and controlling the torque reference to a normal value in response to the network voltage recovery.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: May 8, 2007
    Assignee: ABB Oy
    Inventors: Jukka Ylppö, Kari Turunen
  • Patent number: 7211989
    Abstract: A method for acceleration of a shaft run that a turbine, in particular a gas turbine, a generator and an excitation machine connected to one another by a common shaft, includes accelerating the turbine is accelerated using acceleration apparatus during a starting process, wherein the excitation machine is used as the acceleration apparatus. In addition, an apparatus for performing the method.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: May 1, 2007
    Assignee: Alstom Technology Ltd.
    Inventors: Oliver Drubel, Reinhard Joho
  • Patent number: 7170262
    Abstract: A variable frequency power system with a power source having a rotating output and a speed control to regulate rotational speed of the rotating output. A generator coupled to and driven by the rotating output of the power source, whereby the speed control of the power source directly controls output power frequency of the generator due to control of rotational frequency of the rotating output. A voltage regulator connected between the generator and the motor regulates output voltage from the generator to the electrical motor load. A system controller controls output power frequency of the generator. The system controller interfaces with the speed control of the power source and configured to monitor generator output and operational conditions of the electrical motor load. The system controller adjusts the speed control based on generator output and operational conditions of the electrical motor load.
    Type: Grant
    Filed: December 24, 2003
    Date of Patent: January 30, 2007
    Assignee: Foundation Enterprises Ltd.
    Inventor: Dana Robert Pettigrew
  • Patent number: 7151359
    Abstract: A variable reluctance generator has phase windings and a bias winding. By controlling the excitation produced by the bias winding, the speed of the machine or the DC link, a power converter using only diodes can supply power to a DC bus. A method of operating a variable reluctance machine as a generator, the machine having at least one phase winding, includes creating a bias flux linking the or at least one phase winding, and limiting the phase voltage to a magnitude below that otherwise induced in the phase winding by the bias flux.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: December 19, 2006
    Assignee: Switched Reluctance Drives Limited
    Inventors: Steven Paul Randall, Joseph Gerald Marcinkiewicz
  • Patent number: 7061211
    Abstract: A gas turbine generating apparatus according to the present invention comprises a gas turbine capable of a high-speed operation, a permanent-magnet-type generator driven at a high speed by the gas turbine, an inverter device (5) for converting alternating-current power generated by the generator into commercial alternating-current power, and a system-interconnection device (9) for interconnecting output of the inverter device to a commercial AC power supply system (10). The system-interconnection device controls the inverter device based on voltage of the commercial AC power supply system as a criterion such that output current of the inverter device is in phase with the voltage or out of phase with the voltage by a constant phase difference.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: June 13, 2006
    Assignees: Ebara Corporation, Ebara Densan Ltd.
    Inventors: Motoyasu Satoh, Seiichi Ishihara, Noboru Kinoshita, Takahide Ozawa, Shao-jun Zheng, Terence Mckelvey, Tadashi Kataoka
  • Patent number: 7030593
    Abstract: The present invention relates to variable speed constant frequency (VSCF) devices and methods for maximizing engine generator efficiency. In one embodiment, a VSCF device may include at least two paths for conducting power to the load. One path, a line inductor path, may advantageously incur minimal power loss when the engine generator is supplying rated power to a load. A second path, a VSCF path, may be used to ensure that the frequency of the power is maintained at a substantially constant frequency under various load conditions. Another embodiment of the invention describes a process for determining optimal engine generator speed for a particular load. Because engine speed can be varied using any VSCF device, this process determines a speed that minimizes fuel consumption, emissions, and noise pollution for a given load.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: April 18, 2006
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, III, David A. Badger
  • Patent number: 6992465
    Abstract: A generator control circuit of an ac generator which charges a battery includes a voltage regulator, a comparator which provides a control signal for controlling the voltage regulator when the output voltage of the ac generator is higher than a predetermined voltage and an alarming device which operates when the comparator does not provide the control signal. The predetermined voltage is set higher than voltage of the battery when the battery is open and equal to or lower than a regulation voltage of the ac generator.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: January 31, 2006
    Assignee: Denso Corporation
    Inventor: Toru Aoyama
  • 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: 6888263
    Abstract: A gas turbine generating apparatus according to the present invention comprises a gas turbine capable of a high-speed operation, a permanent-magnet-type generator driven at a high speed by the gas turbine, an inverter device (5) for converting alternating-current power generated by the generator into commercial alternating-current power, and a system-interconnection device (9) for interconnecting output of the inverter device to a commercial AC power supply system (10). The system-interconnection device controls the inverter device based on voltage of the commercial AC power supply system as a criterion such that output current of the inverter device is in phase with the voltage or out of phase with the voltage by a constant phase difference.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: May 3, 2005
    Assignees: Ebara Corporation, Ebara Densan Ltd.
    Inventors: Motoyasu Satoh, Seiichi Ishihara, Noboru Kinoshita, Takahide Ozawa, Shao-jun Zheng, Terence Mckelvey, Tadashi Kataoka
  • Patent number: 6882060
    Abstract: A turbine generating apparatus includes a control unit which controls the turbine generating apparatus as follows. During a system connection running mode, a fuel is fed to the gas turbine at a fuel flow rate corresponding to a preset load. The converter prepares a pseudo-system in which a frequency conforms to a set rotational speed of the gas turbine at the preset load, and converts an output of the generator to a direct current in a state that a number of revolutions of the gas turbine is specified by operating the generator synchronously with the pseudo-system. A power to be taken out is controlled depending on a magnitude of a turbine output. The inverter converts a DC voltage output from the converter to an AC voltage by a pulse width modulation at a system voltage and a system frequency so as to keep the DC voltage output from the converter at a predetermined voltage.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: April 19, 2005
    Assignee: Kawasaki Jukogyo Kabushiki Kaisha
    Inventors: Kazuya Matsuo, Masahide Kawamura, Osamu Noro, Tatsuo Fujii
  • Patent number: 6844706
    Abstract: The present invention relates to variable speed constant frequency (VSCF) devices and methods for maximizing engine generator efficiency. In one embodiment, a VSCF device may include at least two paths for conducting power to the load. One path, a line inductor path, may advantageously incur minimal power loss when the engine generator is supplying rated power to a load. A second path, a VSCF path, may be used to ensure that the frequency of the power is maintained at a substantially constant frequency under various load conditions. Another embodiment of the invention describes a process for determining optimal engine generator speed for a particular load. Because engine speed can be varied using any VSCF device, this process determines a speed that minimizes fuel consumption, emissions, and noise pollution for a given load.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: January 18, 2005
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, III, David A. Badger
  • Patent number: 6781331
    Abstract: A method and system of regulating an output voltage of a boiling water reactor nuclear reactor plant recirculation system motor generator are provided. The method includes sensing an alternator output voltage and transmitting an alternator output voltage signal to a voltage regulator circuit, sensing an alternator speed and transmitting an alternator speed signal to the voltage regulator circuit, comparing the alternator output voltage signal to the alternator speed signal with a volts per hertz divider network electrically coupled to the alternator output voltage sensing circuit and the alternator speed sensing device, adjusting a capacitive reactance of the voltage regulator with a lead compensation circuit electrically coupled in series with the volts per hertz divider network, and adjusting a current in a control winding of a saturable reactor.
    Type: Grant
    Filed: September 13, 2002
    Date of Patent: August 24, 2004
    Assignee: General Electric Company
    Inventors: James Steven Mokri, Nelso Petroni, William Michael Steiner, Stephen L. Joslin, Craig Ernest Leighty
  • Publication number: 20040124813
    Abstract: The present invention relates to variable speed constant frequency (VSCF) devices and methods for maximizing engine generator efficiency. In one embodiment, a VSCF device may include at least two paths for conducting power to the load. One path, a line inductor path, may advantageously incur minimal power loss when the engine generator is supplying rated power to a load. A second path, a VSCF path, may be used to ensure that the frequency of the power is maintained at a substantially constant frequency under various load conditions. Another embodiment of the invention describes a process for determining optimal engine generator speed for a particular load. Because engine speed can be varied using any VSCF device, this process determines a speed that minimizes fuel consumption, emissions, and noise pollution for a given load.
    Type: Application
    Filed: August 30, 2002
    Publication date: July 1, 2004
    Applicant: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David A. Badger
  • Publication number: 20040095100
    Abstract: DC input energy is converted into DC output voltage which is used to create an output RF waveform for use in electrosurgery, by the use of a switched current mode high-voltage power supply. Pulses of input current are switched through a conversion transformer and the energy content of each pulse is converted into the DC output voltage. The time widths of the input current pulses are regulated relative to the DC output voltage, the magnitude of the current within each input current pulse, and in relation to maintaining a plurality of different selected operational conditions. The rate at which the input current pulses are converted is changed relative to the level of the DC output voltage.
    Type: Application
    Filed: November 19, 2002
    Publication date: May 20, 2004
    Inventor: Richard Thompson
  • Publication number: 20040041480
    Abstract: A three-phase line synchronous generator with an exciter and generator stage. The exciter stage includes an exciter stator having n poles and an exciter rotor having n poles and disposed for rotation within the exciter stator, and the generator stage includes a generator stator having n poles and a generator rotor having n poles. The generator rotor being mechanically coupled to the exciter rotor and disposed for rotation within the generator stator, wherein the poles of the stators, or the poles of the rotors, are angularly displace by one pole pitch.
    Type: Application
    Filed: February 5, 2003
    Publication date: March 4, 2004
    Inventors: Leo G. Nickoladze, Hildegard K. Marks
  • Patent number: 6700105
    Abstract: A compact induction heating system that is at least partially powered by a source of substantially clean DC current. The induction heating system includes a high frequency inverter with an input connected to a substantially clean DC current source, a first current conductive path including a first capacitor and a first switch closed to cause one half cycle of AC current to flow in the first path by discharging the first capacitor, a second current conductive path including a second capacitor and a second switch closed to cause a second half cycle of AC current to flow in the second path by discharging the second capacitor, a single load inductor in both of the paths with AC current flowing in a first direction through the inductor when the first switch is closed and in a second opposite direction through the inductor when the second switch is closed, and a gating circuit to alternately close the switches at a driven frequency to control heating by the load inductor.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: March 2, 2004
    Assignee: Tocco, Inc.
    Inventor: William Adam Morrison
  • Patent number: 6696675
    Abstract: A compact induction heating system for use on an internal combustion engine driven implement having an engine driven alternator to generate DC current for storage in a battery used as a source of clean DC current of less than 50 volts for ignition of fuel in the engine, the system comprises a high frequency inverter with an input connected to the clean DC current source, a first current conductive path including a first capacitor and a first switch closed to cause DC current to flow in the first path and across the first capacitor, a second current conductive path including a second capacitor and a second switch closed to cause DC current to flow in the second path and across the second capacitor, a single load inductor in both of the paths with DC current flowing in a first direction through the inductor when the first switch is closed and in a second opposite direction through the inductor when the second switch is closed and a gating circuit to alternately close the switches at a driven frequency to contro
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: February 24, 2004
    Assignee: Tocco, Inc.
    Inventor: William Adam Morrison
  • Patent number: 6628005
    Abstract: A power generation system (10) and associated methods to compensate for different power system output frequencies are provided. The system (10) preferably includes a turbine (12) having a turbine rotor (13) positioned to rotate at a preselected rotational frequency and a generator (20) positioned to generate a power system output current at a preselected power system frequency. The generator (20) preferably has a generator stator (22) and a generator rotor (25) positioned within the generator stator (22) to induce electromotive force to the generator stator (22). The generator rotor (25) preferably is coupled to the turbine rotor (13) and driven by the turbine rotor at substantially the same preselected rotational frequency.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: September 30, 2003
    Assignee: Siemens Westinghouse Power Corporation
    Inventors: Robert J. Nelson, Mark Robert Suchor
  • Patent number: 6628103
    Abstract: A power factor control apparatus comprises a target power factor setting section which sets a target power factor range of the plurality of power generators in a fixed cycle, a comparing section which compares a voltage of a bus with a predetermined voltage value range, a first control section which performs control, based on a result of the comparing section, to drop a voltage of at least one power generator whose power factor is the lowest, and raise a voltage of at least one power generator whose power factor is the highest, and a second control section which performs control of a voltage of a power generator, whose power factor is out of the target power factor range, such that the power factor thereof falls within the target power factor range.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: September 30, 2003
    Assignees: Mitsubishi Heavy Industries, Ltd., Mitsubishi Denki Kabushiki Kaisha
    Inventors: Daisuke Sumiya, Shinichi Koyanagi, Hirofumi Araki
  • Patent number: 6624617
    Abstract: The method for stabilizing the voltage of an AC generator with varying (alternating) rotor speed is characterized in that the voltage generated by an AC generator is maintained constant when the rotor speed changes. The control is carried out without the use of electrical contacts by means of a high-frequency pulse generator. The transformer of the high-frequency pulse generator is divided. The rotating part is provided on the rotor axis and the other part is stationary outside the rotor. Both parts are separated by an air gap. Deviations from a preset output voltage are controlling the pulse generator whose pulses are transmitted by the transformer to the power section of the rotor. The complete power section consisting of the coil and the electronic switch is arranged on the rotor so as to transmit only control currents without physical contact.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: September 23, 2003
    Inventors: Walter Holzer, Rudolf Manukov
  • Patent number: 6603289
    Abstract: A vehicle alternator control device has a power transistor, a flywheel diode, a voltage control circuit, a primary power supply circuit, and a secondary power supply circuit. When the alternator starts rotation, the secondary power supply circuit drives the primary power supply circuit when the alternator speed reaches a frequency equivalent to a speed higher than an engine idling speed. When the engine stops and the speed of the alternator drops, the secondary power supply circuit stops the primary power supply circuit when the alternator speed reaches a frequency equivalent to a speed below the engine idling speed.
    Type: Grant
    Filed: October 18, 2001
    Date of Patent: August 5, 2003
    Assignee: Denso Corporation
    Inventors: Makoto Taniguchi, Toshiyo Ogino, Koji Tanaka