Frequency Responsive Devices Or Networks Patents (Class 322/32)
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Patent number: 11418038Abstract: A power generation plant includes a plant device, an AC motor for starting the plant device, at least one DC power source, and an inverter disposed between the at least one DC power source and the AC motor and between the at least one DC power source and an electrical power grid. The inverter is configured to convert DC power from the at least one DC power source to AC power and is capable of selectively supplying the AC power to the AC motor or the electrical power grid.Type: GrantFiled: March 23, 2018Date of Patent: August 16, 2022Assignee: MITSUBISHI HEAVY INDUSTRIES, LTD.Inventors: Hideyuki Uechi, Rikuma Shijo, Kouji Horizoe, Hisanobu Shinoda, Mitsufumi Goto
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Patent number: 11225910Abstract: Systems and methods include an AC motor and one or more gas turbine generators configured to provide electrical power to the AC motor. The system also includes a controller configured to control operation of the one or more gas turbine generators by determining that the AC motor is to be started using the electrical power. Upon a determination that the AC motor is to be started using the electrical power, the controller is configured to boost the electrical power prior to starting the AC motor. The controller uses the boosted electrical power to pre-compensate for a drop in an electrical parameter of the electrical power due to an increased demand for the startup of the AC motor.Type: GrantFiled: November 5, 2019Date of Patent: January 18, 2022Assignee: General Electric CompanyInventors: Randall Kleen, Esmeralda Soto
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Patent number: 11038450Abstract: A method of predicting a health status of an integrated drive generator (IDG) includes determining an effective deviation across a plurality of IDG output frequencies for a given IDG operation period. The method includes correlating the effective deviation to an IDG capability to determine a health of the IDG. A system for predicting a health status of an integrated drive generator (IDG) includes an IDG and a generator control unit (GCU) operatively connected to the IDG to determine a plurality of IDG output frequencies for a given IDG operation period. The system includes a central processing unit (CPU) operatively connected to the GCU to receive the IDG output frequencies therefrom. The CPU is configured and adapted to determine an effective deviation across at least some of the plurality of IDG output frequencies for the given IDG operation period, and correlate the effective deviation to an IDG capability to determine a health of the IDG.Type: GrantFiled: May 29, 2019Date of Patent: June 15, 2021Assignee: Hamilton Sundstrand CorporationInventors: Angela Higgins, Mykola Kravchenko, Shashvat Prakash
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Patent number: 11025183Abstract: A system may include an independent speed variable frequency (ISVF) generator configured to convert torque from a shaft to an AC power signal. The ISVF generator may have one or more pole pairs with an equivalent shaft frequency equaling a shaft frequency multiplied by the number of pole pairs. A generator control unit may set a generator output frequency of the ISVF generator equal to a lower frequency limit of an AC bus when the equivalent shaft frequency is less than the lower frequency limit, set the generator output frequency of the ISVF generator equal to an upper frequency limit of the AC bus when the equivalent shaft frequency is greater than the upper frequency limit, and set the generator output frequency of the ISVF generator equal to the equivalent shaft frequency when the equivalent shaft frequency is between the lower frequency limit and the upper frequency limit.Type: GrantFiled: October 1, 2019Date of Patent: June 1, 2021Assignee: THE BOEING COMPANYInventors: Lijun Gao, Shengyi Liu
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Patent number: 10342598Abstract: 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: GrantFiled: August 4, 2017Date of Patent: July 9, 2019Assignee: Ethicon LLCInventors: Gary L. Long, Gregory J. Bakos, David N. Plescia
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Patent number: 10224804Abstract: 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: GrantFiled: March 12, 2018Date of Patent: March 5, 2019Assignee: DELTA ELECTRONICS, INC.Inventors: Lei-Chung Hsing, Kuo-Ying Liu
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Patent number: 9895186Abstract: 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: GrantFiled: January 3, 2014Date of Patent: February 20, 2018Assignee: CovidienInventor: James A. Gilbert
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Patent number: 9793703Abstract: 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: GrantFiled: March 21, 2016Date of Patent: October 17, 2017Assignee: ALSTOM Renewable Technologies Wind B.V.Inventor: Julio Cesar Urresty
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Patent number: 9788885Abstract: 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: GrantFiled: February 18, 2016Date of Patent: October 17, 2017Assignee: Ethicon Endo-Surgery, Inc.Inventors: Gary L. Long, Gregory J. Bakos, David N. Plescia
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Patent number: 9752941Abstract: 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: GrantFiled: September 5, 2013Date of Patent: September 5, 2017Assignees: SAMSUNG ELECTRONICS CO., LTD., SUNGKYUNKWAN UNIVERSITY FOUNDATION FOR CORPORATE COLLABORATIONInventors: Sang-hun Jeon, Jong-jin Park, Thanh Tien Nguyen, Ji-hyun Bae, Kyung-eun Byun, Nae-eung Lee, Do-il Kim, Quang Trung Tran
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Patent number: 9735582Abstract: 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: GrantFiled: June 19, 2015Date of Patent: August 15, 2017Assignee: Electromechanical Engineering Associates, Inc.Inventors: Andrew J. Spisak, Alan J. Spisak
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Patent number: 9621090Abstract: 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: GrantFiled: August 20, 2015Date of Patent: April 11, 2017Assignee: ROLLS-ROYCE plcInventors: Ellis F H Chong, Andrew Mackay
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Patent number: 9331611Abstract: 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: GrantFiled: December 15, 2014Date of Patent: May 3, 2016Assignee: LSIS CO., LTD.Inventor: Kyungsue Kim
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Patent number: 9264028Abstract: 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: GrantFiled: December 11, 2013Date of Patent: February 16, 2016Assignee: MARVELL WORLD TRADE LTD.Inventor: David Cousinard
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Publication number: 20140347019Abstract: 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: ApplicationFiled: May 27, 2014Publication date: November 27, 2014Inventors: Jean-Louis Lando, Pierre Valin-Saunal
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Patent number: 8860381Abstract: 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: GrantFiled: July 16, 2012Date of Patent: October 14, 2014Assignee: Sunpower, Inc.Inventor: Ezekiel S. Holliday
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Patent number: 8816605Abstract: 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: GrantFiled: October 21, 2008Date of Patent: August 26, 2014Inventor: Zheng He
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Patent number: 8754615Abstract: 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: GrantFiled: June 1, 2011Date of Patent: June 17, 2014Assignee: General Electric CompanyInventors: James Michael Fogarty, Gary Edward Gottung, David Mark Stuebner
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Publication number: 20140062425Abstract: 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: ApplicationFiled: August 31, 2012Publication date: March 6, 2014Applicant: General Electric CompanyInventors: Cyrus David Harbourt, Robert Gregory Wagoner, Luis José Garcés Rivera
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Publication number: 20140015497Abstract: 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: ApplicationFiled: July 16, 2012Publication date: January 16, 2014Applicant: SUNPOWER, INC.Inventor: Ezekiel S. Holliday
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Patent number: 8513911Abstract: 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: GrantFiled: August 22, 2011Date of Patent: August 20, 2013Assignee: Converteam Technology Ltd.Inventors: Rodney Jones, Christopher Newton
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Publication number: 20120306458Abstract: 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: ApplicationFiled: June 1, 2011Publication date: December 6, 2012Applicant: GENERAL ELECTRIC COMPANYInventors: James Michael Fogarty, John Noel Cunningham, Gary Edward Gottung, David Mark Stuebner
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Patent number: 8294431Abstract: 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: GrantFiled: July 13, 2009Date of Patent: October 23, 2012Assignee: Generac Power Systems, Inc.Inventors: Graham W. McLean, David Pollock, Francis X. Wedel
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Patent number: 8134344Abstract: 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: GrantFiled: July 15, 2008Date of Patent: March 13, 2012Assignee: Honeywell International, Inc.Inventor: David Hodge
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Patent number: 8080950Abstract: 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: GrantFiled: March 15, 2010Date of Patent: December 20, 2011Assignee: Unico, Inc.Inventors: Thomas L. Beck, Michael D. Dry, Mark E. Garlow, Michael O. Lucas, Michael A. MacDonald, Ronald G. Peterson
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Patent number: 8004250Abstract: 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: GrantFiled: June 17, 2008Date of Patent: August 23, 2011Inventor: Peter Grandics
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Publication number: 20110068753Abstract: 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: ApplicationFiled: November 24, 2010Publication date: March 24, 2011Applicant: HONEYWELL INTERNATIONAL INC.Inventors: MINGZHOU XU, CRISTIAN E. ANGHEL, WAYNE T. PEARSON
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Publication number: 20110006547Abstract: 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: ApplicationFiled: July 13, 2009Publication date: January 13, 2011Inventors: Graham W. McLean, David Pollock, Francis X. Wedel
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Patent number: 7830127Abstract: 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: GrantFiled: March 7, 2007Date of Patent: November 9, 2010Assignee: Wind To Power System, S.L.Inventors: Jose Manuel Corcelles Pereira, Jose Luis Rodriguez-Amenedo, Santiago Arnaltes-Gómez
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Publication number: 20100277134Abstract: 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: ApplicationFiled: January 6, 2009Publication date: November 4, 2010Applicant: WOODWARD SEG GMBH & CO. KGInventors: Stephan Engelhardt, Andrzej Geniusz
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Patent number: 7501798Abstract: 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: GrantFiled: July 11, 2007Date of Patent: March 10, 2009Assignee: Nordex Energy GmbHInventors: Malte Laubrock, Thomas Paul Woldmann, Soren Bilges
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Publication number: 20080157724Abstract: 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: ApplicationFiled: April 26, 2007Publication date: July 3, 2008Inventor: Souren G. Fattal
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Publication number: 20080143111Abstract: 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: ApplicationFiled: December 12, 2007Publication date: June 19, 2008Inventors: Masaya Ichinose, Shinya Oohara, Motoo Futami, Mitsugu Matsutake
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Patent number: 7215099Abstract: 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: GrantFiled: August 2, 2005Date of Patent: May 8, 2007Assignee: ABB OyInventors: Jukka Ylppö, Kari Turunen
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Patent number: 7211989Abstract: 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: GrantFiled: April 14, 2005Date of Patent: May 1, 2007Assignee: Alstom Technology Ltd.Inventors: Oliver Drubel, Reinhard Joho
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Patent number: 7170262Abstract: 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: GrantFiled: December 24, 2003Date of Patent: January 30, 2007Assignee: Foundation Enterprises Ltd.Inventor: Dana Robert Pettigrew
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Patent number: 7151359Abstract: 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: GrantFiled: January 27, 2004Date of Patent: December 19, 2006Assignee: Switched Reluctance Drives LimitedInventors: Steven Paul Randall, Joseph Gerald Marcinkiewicz
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Patent number: 7061211Abstract: 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: GrantFiled: March 15, 2005Date of Patent: June 13, 2006Assignees: Ebara Corporation, Ebara Densan Ltd.Inventors: Motoyasu Satoh, Seiichi Ishihara, Noboru Kinoshita, Takahide Ozawa, Shao-jun Zheng, Terence Mckelvey, Tadashi Kataoka
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Patent number: 7030593Abstract: 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: GrantFiled: January 14, 2005Date of Patent: April 18, 2006Assignee: Active Power, Inc.Inventors: Joseph F. Pinkerton, III, David A. Badger
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Patent number: 6992465Abstract: 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: GrantFiled: December 8, 2003Date of Patent: January 31, 2006Assignee: Denso CorporationInventor: Toru Aoyama
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Patent number: 6933705Abstract: 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: GrantFiled: February 7, 2003Date of Patent: August 23, 2005Assignee: Chipper Windpower Technology, Inc.Inventor: Lawrence H. Howes
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Patent number: 6888263Abstract: 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: GrantFiled: May 23, 2002Date of Patent: May 3, 2005Assignees: Ebara Corporation, Ebara Densan Ltd.Inventors: Motoyasu Satoh, Seiichi Ishihara, Noboru Kinoshita, Takahide Ozawa, Shao-jun Zheng, Terence Mckelvey, Tadashi Kataoka
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Patent number: 6882060Abstract: 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: GrantFiled: February 19, 2003Date of Patent: April 19, 2005Assignee: Kawasaki Jukogyo Kabushiki KaishaInventors: Kazuya Matsuo, Masahide Kawamura, Osamu Noro, Tatsuo Fujii
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Patent number: 6844706Abstract: 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: GrantFiled: August 30, 2002Date of Patent: January 18, 2005Assignee: Active Power, Inc.Inventors: Joseph F. Pinkerton, III, David A. Badger
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Patent number: 6781331Abstract: 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: GrantFiled: September 13, 2002Date of Patent: August 24, 2004Assignee: General Electric CompanyInventors: James Steven Mokri, Nelso Petroni, William Michael Steiner, Stephen L. Joslin, Craig Ernest Leighty
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Publication number: 20040124813Abstract: 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: ApplicationFiled: August 30, 2002Publication date: July 1, 2004Applicant: Active Power, Inc.Inventors: Joseph F. Pinkerton, David A. Badger
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Publication number: 20040095100Abstract: 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: ApplicationFiled: November 19, 2002Publication date: May 20, 2004Inventor: Richard Thompson
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Publication number: 20040041480Abstract: 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: ApplicationFiled: February 5, 2003Publication date: March 4, 2004Inventors: Leo G. Nickoladze, Hildegard K. Marks
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Patent number: 6700105Abstract: 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: GrantFiled: March 19, 2002Date of Patent: March 2, 2004Assignee: Tocco, Inc.Inventor: William Adam Morrison
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Patent number: 6696675Abstract: 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 controType: GrantFiled: August 10, 2001Date of Patent: February 24, 2004Assignee: Tocco, Inc.Inventor: William Adam Morrison