Power Factor Or Phase Relationships Patents (Class 322/20)
  • Patent number: 10427527
    Abstract: The present disclosure provides an apparatus with a prime mover coupled to a generator that is directly electrically coupled to an electric motor. A propeller or fan may be coupled to and driven by the electric motor. A bi-directional power converter may be coupled to the generator and further coupled to an energy storage device. The energy storage device may be selectively coupled to the electric motor. Methods of using the apparatus are also provided.
    Type: Grant
    Filed: February 19, 2018
    Date of Patent: October 1, 2019
    Assignees: Rolls-Royce Corporation, Rolls-Royce North American Technologies, Inc.
    Inventors: William L. Siegel, Rigoberto J. Rodriguez, Mark J. Blackwelder, John T. Alt
  • Patent number: 10181728
    Abstract: A control system includes memory storing instructions and a processor configured to execute the instructions. The processor is configured to receive a first indication of a power grid voltage, receive a second indication of a power grid phase angle, receive a third indication of a generator voltage of power provided by a generator, and receive a fourth indication of a generator phase angle of power provided by the generator. The processor is configured to determine a voltage gap between the generator voltage and the power grid voltage and a time difference between the generator phase angle and the power grid phase angle. The processor is configured to generate a signal to cause the generator voltage and the generator phase angle to synchronize with the power grid voltage and the power grid phase angle, respectively.
    Type: Grant
    Filed: March 22, 2016
    Date of Patent: January 15, 2019
    Assignee: GENERAL ELECTRIC COMPANY
    Inventors: Tabrez Shakeel, Randall John Kleen, Muhammed Rahim
  • Patent number: 9991712
    Abstract: A reactive power compensation apparatus includes one or more phase clusters each comprising a plurality of cells, and a controller controlling the one or more phase clusters. When at least one cell in a specific phase cluster among the one or more phase clusters is faulty, the controller controls a voltage of each cell in each of the remaining phase clusters except for the specific phase cluster to be controlled, using a modulation index.
    Type: Grant
    Filed: September 11, 2017
    Date of Patent: June 5, 2018
    Assignee: LSIS CO., LTD.
    Inventors: Yong Ho Chung, Gum Tae Son
  • Patent number: 9910079
    Abstract: A grounding resistance measurement apparatus measures a grounding resistance at an AC power terminal, and is electrically connected to an equipment input terminal which provides an AC power source. The grounding resistance measurement apparatus includes a DC power generation circuit and a DC voltage detection circuit. The DC power generation circuit receives the AC power source at the equipment input terminal and converts the AC power source into a DC power source. The DC power source is provided to produce a DC resistance voltage across the grounding resistance. A voltage difference between the equipment input terminal and an equipment grounding point is equal to the DC resistance voltage so that the grounding resistance is calculated according to the zero DC component in an AC power loop.
    Type: Grant
    Filed: October 22, 2015
    Date of Patent: March 6, 2018
    Assignee: DELTA ELECTRONICS, INC.
    Inventor: Tsung-Yuan Wu
  • Patent number: 9780701
    Abstract: An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.
    Type: Grant
    Filed: December 30, 2015
    Date of Patent: October 3, 2017
    Assignee: Nidec Motor Corporation
    Inventors: Darko Marcetic, Mile Bozic
  • Patent number: 9702908
    Abstract: A method for operating a power generation system coupled to a power grid during a grid unbalance event, a method for determining an injection current to be supplied into a power grid by a power generation system, and a method for addressing an asymmetric grid fault in a power grid connected to a power generation system are provided. The methods may be carried out based on a reactive or an active power/current priority.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: July 11, 2017
    Assignee: VESTAS WIND SYSTEMS A/S
    Inventors: Amit Kumar Gupta, John Godsk Nielsen, Liang Yang
  • Patent number: 9685893
    Abstract: An alternating current generation system is provided. In the system, in a rotor, a plurality of detection subject portions are arrayed along a circumferential direction in correspondence to reversal states of the magnetic poles in a plurality of magnetized portions. A detecting unit is disposed opposing the rotor so as to generate an output signal corresponding to passage state of the detection subject portions. A phase control unit outputs, to a power converter, a control signal to perform phase control of switching elements depending on the rotation phase of the rotor, based on the output signal from the detecting unit.
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: June 20, 2017
    Assignee: DENSO CORPORATION
    Inventors: Yasuhiro Fuwa, Kanechiyo Terada, Osamu Naitou, Kouichi Nagata, Masaaki Ohno
  • Patent number: 9595901
    Abstract: The invention relates to a method for regulating the output voltage of the alternator of a generator set, said generator set including a heat engine driving the alternator, the alternator including a rotor having a pole wheel. Said method includes the following step: detection of an increase in the power at the outlet of the alternator, and in the event of a detected increase, the value of the current in the polar wheel is modified in such a way as to temporarily bring the output voltage of the alternator to a value lower than the value before the detection of the increase in power, with the aim of decreasing the level of torque required from the heat engine.
    Type: Grant
    Filed: September 3, 2012
    Date of Patent: March 14, 2017
    Assignee: MOTEURS LEROY-SOMER
    Inventors: Jean-Marie Andrejak, Samuel Moser, Patrice Betge
  • Patent number: 9590545
    Abstract: In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. A sensor, which is supported by the rotor, is configured to generate a trigger signal indicative of a position of the rotor. A communication interface is configured to receive the trigger signal from the sensor of the rotor and receive data indicative of an output of the generator. A controller supported by the rotor or configured to perform a phase analysis of the trigger signal and the output of the generator and calculate a power angle for the generator based on the phase analysis.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: March 7, 2017
    Assignee: Kohler, Co.
    Inventors: Isaac S. Frampton, Adam Larson, Richard Van Maaren
  • Patent number: 9553444
    Abstract: A device for suppressing high-voltage electricity is connected to a three-phase circuit of an electric generator, including three up arm semiconductor switches, three low arm semiconductor switches, three reverse breakdown diodes respectively connected to the low arm semiconductor switches in parallel, and a control circuit sending PWM signals to turn on and off the low arm semiconductor switches sequentially to evenly share and absorb the energy of surge voltage. Each of the up arm semiconductor switches has a first terminal and a second terminal, wherein the first terminals are electrically connected together, and the second terminals are respectively electrically connected to one of three coils of the three-phase circuit. Each of the low arm semiconductor switches has a first terminal and a second terminal, wherein the first terminals are respectively electrically connected to the second terminals of the up arm semiconductor switches, and the second terminals are electrically connected together.
    Type: Grant
    Filed: December 11, 2015
    Date of Patent: January 24, 2017
    Assignee: MOBILETRON ELECTRONICS CO., LTD.
    Inventor: Chen-Ku Wei
  • Patent number: 9525285
    Abstract: Energy systems and energy supply methods are described. In one aspect, an energy system includes a bus system configured to conduct electrical energy, a plurality of input adapters electrically coupled with the bus system and configured to electrically couple with a plurality of respective source entities which are individually configured to provide electrical energy, a plurality of output adapters electrically coupled with the bus system and configured to electrically couple with a plurality of respective consuming entities which are individually configured to consume electrical energy, and control circuitry configured to control individual ones of the input adapters to provide electrical energy from respective ones of the source entities to the bus system and to control individual ones of the output adapters to provide electrical energy from the bus system to respective ones of the consuming entities.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: December 20, 2016
    Assignee: Demand Energy Networks, Inc.
    Inventors: Shane Johnson, Allan Coxon, Ian Walker
  • Patent number: 9395722
    Abstract: A method for protecting a synchronous machine (2) against damage caused by pole slipping in a power generating unit or a drive unit (1) in an electric power network is disclosed. The method measures signals of current and voltage of the synchronous machine (2) and assumed constant parameters to determine a disturbance (Trig_start). When a disturbance is detected, an indicator of pole slipping is determined, and the time of rotor operation with the occurrence of pole slipping is totalized. Next, if a threshold value allowed for the rotor operation with slipping proves to be valid, corresponding measures protecting the synchronous machine (2) against slipping are implemented. If the detection process is not fulfilled, the process of sudden disturbance and/or the process of accrued detection is conducted until the criterion of pole slipping occurrence is fulfilled for the generator mode or for the motor mode.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: July 19, 2016
    Assignee: ABB TECHNOLOGY AG
    Inventors: Jaroslaw Krata, Arkadiusz Burek
  • Patent number: 9354622
    Abstract: The method of controlling a polyphase rotating electric machine, the machine operating as a generator and being linked to an electrical network (1), is of the type of those consisting in short-circuiting at least one phase winding in the event of load shedding. A short-circuit command (SAND) is generated for the phase winding when a first measurement voltage V of a voltage B+ of the network exceeds a first predetermined threshold value V1 and when a phase current (I?) in the phase winding vanishes and changes direction. The first measurement voltage V may be obtained by filtering the voltage B+ of the network with a predetermined time constant TF.
    Type: Grant
    Filed: April 19, 2012
    Date of Patent: May 31, 2016
    Assignee: Valeo Equipements Electriques Moteur
    Inventors: Philippe Masson, Thierry Mandion, Damien Chaumat
  • Patent number: 9318979
    Abstract: A converter arrangement has at least one AC voltage connection, at which an alternating current can be fed in or drawn, and at least one DC voltage connection, at which a direct current can be fed in or drawn. The converter arrangement contains at least two series circuits connected in parallel. The external connections of the series circuits form the DC voltage connections of the converter arrangement. Each of the series circuits is connected in parallel and contains in each case at least two submodules connected in series, each of the submodules containing at least two switches and a capacitor. An energy store is to be connected to the capacitor of at least one of the submodules, wherein a filter is connected electrically between the capacitor and the energy store.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: April 19, 2016
    Assignee: Siemens Aktiengesellschaft
    Inventors: Dieter Fischer, Alexander Hahn, Uwe Krebs, Holger Leu, Jean-Philippe Macary, Andreja Rasic, Wolfgang Weydanz
  • Patent number: 9300236
    Abstract: A process for increasing the excitation current, particularly when activating the alternator, whose rectified alternator voltage is regulated by way of a regulator, is provided. For regulating the alternator voltage, the regulator sets the excitation current of an excitation winding of the alternator. The regulator further receives a phase signal. A rapid increasing of the excitation current to a defined value takes place, during which the phase signal is analyzed simultaneously. This rapid increasing continues until the phase signal or a quantity derived therefrom meets a defined condition with respect to the alternator voltage. Therefore, a further increasing of the excitation current takes place, preferably at a rate of change reduced with respect to the previous rapid increase.
    Type: Grant
    Filed: June 11, 2014
    Date of Patent: March 29, 2016
    Assignee: Bayerische Motoren Werke Aktiengesellschaft
    Inventors: Almas Kadric, Volkmar Witting, Christoph Sudan
  • Patent number: 9263983
    Abstract: A vibration generating apparatus with high yield, low cost, and can exhibit vibration tactile haptic effects even with variation in the natural frequency of a mechanical vibrator, including a damping system having a damping ratio ?<1 to support a mechanical vibrator to a fastening part, and a magnetizing unit generating a dynamic magnetic field to vibrate the mechanical vibrator by non-contact, the mechanical vibrator generating a beat vibration by making the frequency of a drive voltage applied to the magnetizing unit, from a drive start or middle of drive, to be a non-resonant frequency out of a damped natural frequency of the mechanical vibrator, wherein the apparatus comprises a forced vibration control unit controlling to stop application of the drive voltage, in a beat wave defining an amplitude of the beat vibration, at a second valley part after a first peak part from the side of the drive start.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: February 16, 2016
    Assignee: NIDEC SEIMITSU CORPORATION
    Inventor: Masahiko Miyazaki
  • Patent number: 9203327
    Abstract: A rectifier bridge circuit is described for rectifying the phase voltage generated by a generator, including a positive half-bridge having multiple rectifier elements and a negative half-bridge having multiple rectifier elements. The rectifier elements each have a controllable switch having a diode connected in parallel. A control circuit is provided for switching the switches on and off. The switch-on time tswitch on setpoint and/or the switch-off time tswitch off setpoint of the switch is/are computed based on a characteristic map or a mathematical function.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: December 1, 2015
    Assignee: ROBERT BOSCH GMBH
    Inventors: Gert Wolf, Paul Mehringer, Kurt Reutlinger, Gerhard Walter
  • Patent number: 9133825
    Abstract: There is provided a power generation park (100) having a power output (108) for providing electrical output power (150) to an electricity network (128). A power generation device (102a, . . . 102n) has a converter device (106) configured for receiving input power (142) from a power generator (104) and providing, in response thereto, the electrical output power (150) to the power output (112). The power generation park (100) also has a controller (122) being configured for receiving an oscillation indicating signal (126) indicative of a power oscillation in the electricity network (108), the controller (122) being further configured for providing a damping control signal (132) in response to the oscillation indicating signal (126); the converter device (106) being configured for modulating the electrical output power (150) in response to the damping control signal (132) so as to damp the power oscillation in the electricity network (128).
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: September 15, 2015
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Björn Andresen, Michael Noertoft Frydensbjerg, Thyge Knüppel
  • Patent number: 9035480
    Abstract: A method is employed for operating a wind turbine. Electrical energy is produced by means of a generator and is fed into an electrical power network. The electrical energy is fed to the secondary side of a transformer at a low voltage and is output on the primary side of the transformer at a higher voltage. The potential on the primary side of the transformer is undefined. In the method, a measured value of the voltage between the primary side of the transformer and the earth potential is first recorded. The measured value is compared with a predefined limit value. The electrical energy produced by the generator is changed if the measured value exceeds the limit value. A wind turbine is designed to carry out the method. Faults in the medium voltage network can be reacted to without an additional star point on the primary side of the transformer being required.
    Type: Grant
    Filed: June 3, 2011
    Date of Patent: May 19, 2015
    Assignee: Senvion SE
    Inventor: Jens Fortmann
  • Patent number: 9030174
    Abstract: Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a doubly fed induction generator (DFIG) system are provided. A control system can monitor the bridge current of each of the bridge circuits coupled in parallel and generate a feedback signal indicative of the difference in bridge current between the parallel bridge circuits. Command signals for controlling the bridge circuits can then be developed based on the feedback signal to reduce current imbalance between the bridge circuits. For instance, the pulse width modulation of switching devices (e.g. IGBTs) used in the bridge circuits can be modified to reduce current imbalance between the parallel bridge circuits.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: May 12, 2015
    Assignee: General Electric Company
    Inventors: Robert Gregory Wagoner, Robert Allen Seymour
  • Publication number: 20150123623
    Abstract: An electric power generation plant has at least two synchronous machines and a source of mechanical power (torque), coupleable such that one or more of the synchronous machines can be operated as a generator while one or more is operated as a synchronous condenser. Field exciters, controlled shaft couplings, starters and switching sequences control starting, restarting and switching into simultaneous operation as generators, as condensers, or as one or more generators and condensers synchronously coupled to one another along a drive train. The disclosed configurations include modifications of existing generator installations such as decommissioned plants, such as by controllably coupling a second synchronous machine to a drive train, for use as a condenser for power factor control when needed or as an added source of generator capacity during times of high demand.
    Type: Application
    Filed: November 6, 2013
    Publication date: May 7, 2015
    Applicant: Bechtel Power Corporation
    Inventors: Seyfettin C. Gülen, Mark S. Boulden
  • Patent number: 8975878
    Abstract: A method of controlling a generator (110) of an electric drive (104) associated with an engine (102) is provided. The method may determine an operational state of the electric drive (104) based on a speed of the engine (102), and selectively engage one of a map-lookup control scheme (150) and a fixed-theta off control scheme (152) for operating the generator (110) based on the operational state of the electric drive (104).
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: March 10, 2015
    Assignee: Caterpillar Inc.
    Inventors: Jackson Wai, Thuong Le, Adam Braun, Jesse Gerdes, James Siegle, Mark Hartman
  • Patent number: 8970057
    Abstract: According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: March 3, 2015
    Assignee: Vestas Wind Systems A/S
    Inventors: Bing Li, Anshuman Tripathi, Shu Yu Cao, Amit Kumar Gupta, Eng Kian Kenneth Sng, Lars Helle
  • Publication number: 20150022132
    Abstract: A method for operating an electrical machine having a stator 1 with a coil from electrical conductors, which has two coil ends 2 lying opposite each other. The method includes simultaneously recording vibration measurements by means of which the elliptic vibration modes of the two coil ends 2 can be determined as a factor of time; determining the ellipse inclinations and the phase positions of elliptic vibration modes of the two coil ends 2; determining critical operating states of the electrical machine, in which the elliptic inclinations and the phase positions of the elliptic vibration modes of the two coil ends are substantially identical; and operating the electrical machine in such a manner that the critical operating states can be avoided by varying the idle power of the electrical machine.
    Type: Application
    Filed: January 15, 2013
    Publication date: January 22, 2015
    Inventor: Sebastian Strack
  • Patent number: 8908336
    Abstract: A fault tolerant electrical machine including: a plurality of phases; a detector arranged to detect a fault in at least one of the phases; and a controller arranged to intentionally cause a fault in at least one other of the phases such that the vector sum of the second harmonic power vectors of the remaining phases is zero.
    Type: Grant
    Filed: January 5, 2011
    Date of Patent: December 9, 2014
    Assignee: Rolls-Royce PLC
    Inventors: John James Anthony Cullen, Stephen Andrew Long
  • Patent number: 8903555
    Abstract: A wind power generator generates power through a rotation of a rotor and is interconnected, and operated with its power generation output previously limited in order to be able to further supply the power to a power system in response to a decrease in system frequency. Thus, a concentrated control system derives a required restricted amount corresponding to a power generation output required to respond to the decrease in system frequency, derives a value by subtracting an amount corresponding to a latent power generation output with which the power generation output can be increased, from the required restricted amount, and sets a restricted amount of the power generation output in each wind power generator to perform the operation with the power generation output previously limited to respond to the decrease in system frequency, based on the above value.
    Type: Grant
    Filed: March 14, 2012
    Date of Patent: December 2, 2014
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Takumi Nakashima, Masayuki Hashimoto, Akira Yasugi, Tsuyoshi Wakasa, Hisanobu Shinoda
  • Patent number: 8884486
    Abstract: A method for regulating the reactive power generated or absorbed by a synchronous electric generator includes regulating a quantity of coils disposed in line with a stator winding. Additionally, a generator operating point of the generator is regulated.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: November 11, 2014
    Assignee: Alstom Technology Ltd.
    Inventor: Johann Haldemann
  • Patent number: 8759995
    Abstract: The control method of a wind turbine generator increases the speed range of wind turbine generators, maximizing the operation and efficiency thereof, in addition to lengthening their service life, on minimizing the extreme and fatigue loads to which the wind turbine generators are subject, and which are due mainly to the stops and disconnections thereof as a result of strong gusts of wind. More specifically, the control method of the present invention stands out essentially for being based on the control of the reactive current circulating through the electric generator, said reactive current control being carried out in accordance with the rotational speed (?g) for the purpose of reducing the voltage at the converter terminals on the generator side, or rotor voltage (VR), which ultimately allows a transitional increase in the speed range of the wind turbine generator.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: June 24, 2014
    Assignee: Acciona Windpower, S.A.
    Inventors: José Miguel García Sayés, Teresa Arlabán Gabeiras, Miguel Núñez Polo
  • Publication number: 20140111167
    Abstract: Systems, methods, and a voltage regulator are provided for tuning reactive droop compensation of a generator in a parallel power generation system. The voltage regulator is configured to compute a simulated droop compensation voltage for the generator and control an excitation signal to the generator based at least in part on the simulated droop compensation voltage.
    Type: Application
    Filed: October 18, 2012
    Publication date: April 24, 2014
    Applicant: RBC MANUFACTURING CORPORATION
    Inventors: David Bruce Hyypio, Myron Roman Mychal
  • Patent number: 8653797
    Abstract: A synchronous electrical machine comprises a plurality of phases and detecting means arranged to detect an open-circuit fault in at least one of the phases of the synchronous electrical machine. Isolating means is arranged to isolate the at least one phase of the synchronous electrical machine with the fault. Phase shift means are arranged to produce a controlled phase shift between the voltage and the current within the remaining phases of the synchronous electrical machine so as to adjust the phase angle of the second harmonic powers produced by the remaining phases of the synchronous electrical machine such that the vector sum of the second harmonic power vectors of the remaining phases of the synchronous electrical machine is zero to eliminate torque ripple. The phase shift means is arranged to adjust the phase angle of all the remaining phases by the same predetermined angle to maximize the torque ripple-free power output of the synchronous electrical machine.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: February 18, 2014
    Assignee: Rolls-Royce PLC
    Inventors: John J. A. Cullen, David R. Trainer, Stephen A. Long, Angus G. L. Moodie
  • Patent number: 8593114
    Abstract: The present invention relates to a control device for a doubly-fed induction generator in which a feedback linearization method is enabled and further provides a control device for a doubly-fed induction generator in which a feedback linearization method is embedded, characterized in that the control device divides and measures positive sequency components and negative sequency components from stator voltage and current, rotor voltage and current, and signals of stator magnetic flux and rotor magnetic flux of the doubly-fed induction generator.
    Type: Grant
    Filed: December 27, 2010
    Date of Patent: November 26, 2013
    Assignee: Korea Electrotechnology Research Institute
    Inventors: Jung Woo Park, Dae Wook Kang, Ji Woo Moon, Jin Soo Kwon, Deuk Woo Pae, Chang Hun Oh
  • Patent number: 8588984
    Abstract: A new method for predicting the rotor angle stability status of a power system immediately after a large disturbance is presented. The proposed two stage method involves estimation of the similarity of post-fault voltage trajectories of the generator buses after the disturbance to some pre-identified templates and then prediction of the stability status using a classifier which takes the similarity values calculated at the different generator buses as inputs. The typical bus voltage variation patterns after a disturbance for both stable and unstable situations are identified from a database of simulations using fuzzy C-means clustering algorithm. The same database is used to train a support vector machine classifier which takes proximity of the actual voltage variations to the identified templates as features.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: November 19, 2013
    Inventor: Athula Dayanarth Rajapaske
  • Patent number: 8577508
    Abstract: Embodiments according to the present invention provide methods and a system for a control approach that effectively maintains the DC link voltage at a constant set value under variable system conditions and keeps the converter operating within an optimal power factor range.
    Type: Grant
    Filed: May 5, 2008
    Date of Patent: November 5, 2013
    Assignee: University of Alabama
    Inventors: Shuhui Li, Timothy A. Haskew
  • Patent number: 8536722
    Abstract: In a wind turbine generator, the rotation of the rotor is speeded up by a hydraulic pump and a hydraulic motor and is transferred to a synchronous generator. In a state in which the wind turbine generator is interconnected to a utility grid, and the synchronous generator reaches a synchronous speed, if no mechanical power is transferred to the synchronous generator, a wind-turbine control system operates the synchronous generator as a synchronous condenser, thus controlling the magnitude of the field current of the synchronous generator. Thus, the wind turbine generator can supply reactive power to the utility grid without adding new equipment, such as a reactive power compensator using a semiconductor switch.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: September 17, 2013
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Tsuyoshi Wakasa, Hisanobu Shinoda, Hidekazu Ichinose, Yukio Yamashita, Takatoshi Matsushita
  • Publication number: 20130221934
    Abstract: In a wind turbine generator, the rotation of the rotor is speeded up by a hydraulic pump and a hydraulic motor and is transferred to a synchronous generator. In a state in which the wind turbine generator is interconnected to a utility grid, and the synchronous generator reaches a synchronous speed, if no mechanical power is transferred to the synchronous generator, a wind-turbine control system operates the synchronous generator as a synchronous condenser, thus controlling the magnitude of the field current of the synchronous generator. Thus, the wind turbine generator can supply reactive power to the utility grid without adding new equipment, such as a reactive power compensator using a semiconductor switch.
    Type: Application
    Filed: January 29, 2013
    Publication date: August 29, 2013
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Tsuyoshi WAKASA, Hisanobu SHINODA, Hidekazu ICHINOSE, Yukio YAMASHITA, Takatoshi MATSUSHITA
  • Patent number: 8513924
    Abstract: The vehicle generator includes an armature winding including a plurality of phase windings, a switching section formed as a bridge circuit constituted of a plurality of pairs of an upper arm and a lower arm connected in series to rectify voltages induced in the phase windings, each of the upper and lower arms being constituted of a switching element parallel-connected with a diode, a control section for controlling on/off timings of the switching elements, and a voltage zero-cross detecting section for performing voltage zero-cross detection to detect, as voltage zero-cross points, time points at which at least one of line-to-line voltages among the phase windings of the armature winding changes in polarity. The control section is configured to start on-off control of the switching elements based on the voltage zero-cross points detected by the voltage zero-cross detecting section.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: August 20, 2013
    Assignee: Denso Corporation
    Inventor: Harumi Horihata
  • Publication number: 20130169241
    Abstract: The control method of a wind turbine generator increases the speed range of wind turbine generators, maximising the operation and efficiency thereof, in addition to lengthening their service life, on minimising the extreme and fatigue loads to which the wind turbine generators are subject, and which are due mainly to the stops and disconnections thereof as a result of strong gusts of wind. More specifically, the control method of the present invention stands out essentially for being based on the control of the reactive current circulating through the electric generator, said reactive current control being carried out in accordance with the rotational speed (?g) for the purpose of reducing the voltage at the converter terminals on the generator side, or rotor voltage (VR), which ultimately allows a transitional increase in the speed range of the wind turbine generator.
    Type: Application
    Filed: December 12, 2012
    Publication date: July 4, 2013
    Applicant: ACCIONA WINDPOWER, S. A.
    Inventor: ACCIONA WINDPOWER, S. A.
  • Patent number: 8450983
    Abstract: A microcomputer that exercises driving control and power-generation control over a motor generator unit and a power-generation maintaining unit that, separately from the power-generation control exercised by the microcomputer, maintains a power-generation process performed by the motor generator unit are provided. While the microcomputer is operating normally, the power-generation maintaining unit allows the microcomputer to exercise the power-generation control. When an abnormality has occurred in the microcomputer, the power-generation maintaining unit acts as a backup or secondary controller to maintain the power-generation process performed by the motor generator unit, in an autonomous manner independently of the microcomputer.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: May 28, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroshi Gokan, Naruki Suetake, Katsuya Tsujimoto
  • Patent number: 8432055
    Abstract: A wind turbine connected to a power grid is provided. The wind turbine is selectively activated to operate at a high-voltage ride through (HVRT) mode. The wind turbine includes a grid voltage circuit, a DC bus, a voltage source, and a dynamic brake. The grid voltage circuit monitors a fundamental voltage of the power grid and activates the HVRT mode if the fundamental voltage is at least about equal to a threshold voltage value. The DC bus has a DC bus voltage. The voltage source provides a DC bus rated voltage. The dynamic brake has a brake chopper and a resistive element. The dynamic brake is connected to the DC bus. The dynamic brake is connected to the voltage source if the HVRT mode is activated.
    Type: Grant
    Filed: December 12, 2011
    Date of Patent: April 30, 2013
    Assignee: General Electric Company
    Inventor: Petar Jovan Grbovic
  • Patent number: 8410761
    Abstract: A control circuit for use with an AC alternator has a plurality of outlet lines leading from the alternator, each receiving a phase of current generated by the alternator. Tap lines are associated with each of the power lines and are associated with a switch. The switches drain power to a drain when in a first state, and allow the power to pass downstream to a system load when in a second state. A switch control changes the switches between the first and second state. A detector detects when the current signal is approaching a zero crossing between a cycle positive portion and a negative portion. The switch control takes in the information with regard to the approaching zero crossing, and change the switches between the first and second states based upon the detected zero crossing point. An alternator is also disclosed.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: April 2, 2013
    Assignee: Hamilton Sundstrand Corporation
    Inventor: Thomas Bekasi
  • Publication number: 20130076316
    Abstract: A method and apparatus are provided for controlling a cascade-fed asynchronous generator in connection with a voltage dip of a network fed by the generator. A frequency converter is connected between the rotor of the asynchronous generator and the network. The method includes measuring the magnitude of the voltage in the network, calculating, on the basis of the voltage in the network, a base value for reactive current to be fed to the network, generating reactive current in the network by the generator, measuring the stator current, determining the actual value of the reactive current in the network, calculating the difference between the base value and the actual value of the reactive current, providing the calculated difference to the frequency converter to serve as an instruction in reactive current, and generating reactive current in the network by the frequency converter in accordance with the instruction in reactive current.
    Type: Application
    Filed: September 21, 2012
    Publication date: March 28, 2013
    Applicant: ABB Oy
    Inventor: Reijo Kalevi VIRTANEN
  • Patent number: 8391420
    Abstract: Various techniques are provided to detect a state of a communication signal. In one example, a method of detecting a state of a signal includes receiving a differential communication signal comprising a positive portion and a complementary negative portion. The method also includes filtering the positive portion of the communication signal through a first low pass filter to provide a filtered positive portion of the communication signal. The method also includes filtering the negative portion of the communication signal through a second low pass filter to provide a filtered negative portion of the communication signal. The method also includes comparing the filtered positive portion of the communication signal with an internal reference voltage. The method also includes comparing the filtered negative portion of the communication signal with the internal reference voltage.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: March 5, 2013
    Assignee: SMSC Holdings S.a.r.l.
    Inventors: Hongming An, Wei Fu, CongQing Xiong, James Ho
  • Patent number: 8368238
    Abstract: It is an object to provide a wind turbine generator system that can promptly restore the system voltage in the event of, for example, a low voltage phenomenon. A controller 21 detects the power factor state of a generator when a normal operation mode is switched to a low-voltage control mode and sets a condition for switching from the low-voltage control mode to the normal operation mode depending on the detected power factor state.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: February 5, 2013
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Akira Yasugi, Takatoshi Matsushita
  • Patent number: 8358036
    Abstract: A control system is provided for use with a plurality of generator sets. The control system may have a bus, an arbitration relay, a switching device, a control module, and first, second, and third discrete signal cables. The control module may be configured to receive a group start signal and initiate startup of a first of the plurality of generator sets, and to generate a signal on the first discrete signal cable based on an operational status of the first of the plurality of generator sets. The control module may also be configured to determine if the second discrete signal cable is active, to activate the second discrete signal cable and the arbitration relay based on the determination, and to activate the switching device to connect the first of the plurality of generator sets to the bus based on a status of the third discrete signal cable.
    Type: Grant
    Filed: December 19, 2011
    Date of Patent: January 22, 2013
    Assignee: Caterpillar Inc.
    Inventors: Chad Eric Dozier, Edward Maurer Schroeder, Matthew Lee Wagner
  • Publication number: 20120248772
    Abstract: An object is to rapidly recover from a voltage drop in a power grid. When the value of a grid voltage detected by a grid voltage detection unit has fluctuated so as to satisfy a condition set in advance for a reference value, a control device controls a wind turbine generator such that a reactive current corresponding to a required output current that is determined by an active current and the reactive current and that indicates an output level to a power grid on the basis of the detection result from the grid voltage detection unit is output to the power grid.
    Type: Application
    Filed: March 20, 2012
    Publication date: October 4, 2012
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Tetsuo SHIGEMIZU, Tsuyoshi WAKASA, Akira YASUGI
  • Patent number: 8278883
    Abstract: Apparatus for measuring load angle in a synchronous generator is disclosed. The synchronous generator is of a type comprising a main machine, an exciter for exciting the main machine, and a permanent magnet machine for exciting the exciter. The apparatus comprises means for sensing a waveform produced by the permanent magnet machine, means for sensing a waveform produced by the main machine, and means (20) for comparing the waveform produced by the permanent magnet machine with the waveform produced by the main machine to produce a measure of load angle. The measure of load angle may be used to provide a warning of potential pole slip.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: October 2, 2012
    Assignee: Cummins Generator Technologies Limited
    Inventor: Denis Hedley Dalby
  • Publication number: 20120223531
    Abstract: A power plant includes an engine coupled to a first generator and a second generator. The first generator includes a synchronous generator wherein the first generator is configured to provide reactive power to the second generator. The second generator includes an induction generator. One or more sensors are configured to measure a current output and a voltage output of the first and second generators, and a controller is configured to determine a power factor for the power plant based on the measured current output and voltage outputs. Based on the determined power factor, the controller adjusts the reactive power provided from the first generator to the second generator such that the power factor is maintained at a predetermined value.
    Type: Application
    Filed: March 2, 2011
    Publication date: September 6, 2012
    Applicant: GOOGLE INC.
    Inventors: Alec Brooks, Zvi Gershony
  • Patent number: 8258759
    Abstract: An anti-islanding implementation that introduces a small, continuously varying phase shift pattern in the output current of an inverter. In grid-connected mode, this phase shift pattern has no impact on the frequency of the inverter's output voltage. However, when islanded, the phase shift will cause the voltage frequency to deviate from nominal. Changes in the output current phase thus correlate well with the voltage frequency, so a covariance index is used to detect an islanding configuration. When this index exceeds a threshold, a larger phase shift pattern is introduced in the output current, large enough to cause the voltage frequency to fall outside the inverter's trip protection window without compromising the inverter's power quality yet ensuring reliable tripping of the inverter.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: September 4, 2012
    Assignee: Xantrex Technology Inc.
    Inventors: Jun Yin, Chi-Sheng Fan, Djordje Garabandic
  • Patent number: 8248038
    Abstract: A scheme for synchronous generator protection is provided. Based on generator input and transformer output phase information, along with the energy function concept, the scheme for synchronous generator protection provides early detection of a loss of synchronism of a generator. As such, the generator with loss of synchronism can be tripped before the generator actually slips. An example for how such a synchronous generator protection schemes may function, is also provided.
    Type: Grant
    Filed: August 28, 2009
    Date of Patent: August 21, 2012
    Assignee: Empire Technology Development LLC
    Inventor: K. R. Padiyar
  • Patent number: 8242753
    Abstract: In a method and an apparatus for controlling the output or drawn active and reactive power of a double-fed asynchronous machine (5), the maintenance of a maximum permissible current (16) of the machine—without the use of a subordinate current controller—is ensured by virtue of the fact that, during the operation of the double-fed asynchronous machine, a maximum permissible desired value for the active power (10a) to be output or to be drawn and a maximum permissible desired value for the reactive power (10b) to be output or to be drawn are calculated with the aid of a model of the asynchronous machine from the maximum permissible current (16), preferably corrected at least using the actual value of the current to be limited of the machine, in such a way that the maximum permissible current (16) is not exceeded. The predetermined active and reactive power desired values are then limited to the calculated maximum permissible values.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: August 14, 2012
    Assignee: Woodward SEG GmbH & Co KG
    Inventors: Stephan Engelhardt, Andrzej Geniusz