By Voltage Regulation Patents (Class 700/298)
  • Publication number: 20120215372
    Abstract: Methods, apparatus and systems for controlling a photovoltaic panel while ensuring the power source operates safely include determining a temperature of the photovoltaic panel, determining a voltage provided from the photovoltaic panel, determining a parameter based on the voltage and the temperature and controlling a power converter based on the determined parameter. The power converter may be a pulse amplitude modulated current converter (PAMCC). The PAMCC may be controlled through tables of pulse durations based on the determined parameter. The voltage output may be controlled through a fast control loop and through a slower control loop, and the power demand from the solar panel may be controlled such that the output voltage does not vary from the expected value by more than a predetermined value.
    Type: Application
    Filed: October 20, 2011
    Publication date: August 23, 2012
    Applicant: Array Converter Inc.
    Inventors: Kent Kernahan, Sorin Spanoche, Aldrin Aviananda, Shiloh Hawley, David Stewart
  • Patent number: 8249758
    Abstract: A power plant for providing electric power to a power grid includes energy sources; power conditioning units and a controller configured to cause power provided to the grid to have selected electrical characteristics. The controller is in high speed real-time communication with the power conditioning units and programmed to provide instructions to the power conditioning units.
    Type: Grant
    Filed: October 6, 2011
    Date of Patent: August 21, 2012
    Assignee: American Superconductor Corporation
    Inventors: Perry S. Schugart, William Vareka, Narendra Reddy
  • Publication number: 20120209447
    Abstract: A communication converter for connecting automation devices having different operating voltages to a host computer, including an interface component and a transceiver component coupled to the interface component, the interface component being connected on the input side via a host connector to a host interface of the host computer and the transceiver component being connected via a device connector to a device interface of the automation device, and a voltage transformer, which on the input side is connected via the host interface to an operating voltage and on the output side to a voltage supply line of the device interface. So the communication converter can communicate with devices having different interface standards, the converter has a first current/voltage measuring unit, a second current/voltage measuring unit, and a switching device.
    Type: Application
    Filed: October 1, 2010
    Publication date: August 16, 2012
    Applicant: SCHNEIDER ELECTRIC AUTOMATION GMBH
    Inventors: Michael Hortig, Philippe Goutaudier, Jun Ye, Qing Li
  • Patent number: 8234015
    Abstract: The present invention relates to a method for controlling a voltage level of a power supply grid operationally connected to a source of electrical power, the method comprising the steps of determining a short circuit impedance of the power supply grid at a point of common coupling, calculating, using the determined short circuit impedance, a gain value of the power supply grid, and controlling the grid voltage level in accordance with the calculated gain value by applying said gain value as a gain parameter in a voltage controller. The method according to the present invention may be implemented as a method for configuring a voltage controller once and for all, or it may be implemented as a method for adaptively adjusting a gain of a voltage controller.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: July 31, 2012
    Assignee: Vestas Wind Systems A/S
    Inventors: John Bech, Peter Nielsen, Philip Carne Kjaer
  • Patent number: 8204632
    Abstract: A load shedding system and method for controlling imbalances in a power system includes a signal generator adapted to generate a signal representative of a local system, and a modifying circuit adapted to adjust set frequencies. The system also includes a processing circuit adapted to process data received from the signal generator and modifying circuit and set load shedding priorities for the local system based on the processed data.
    Type: Grant
    Filed: June 3, 2008
    Date of Patent: June 19, 2012
    Assignee: Electric Power Research Institute, Inc.
    Inventor: Nicholas C. Abi-Samra
  • Patent number: 8190300
    Abstract: A method for the operation of a wind farm having two or more wind energy plants, which has a farm control which presets a desired value for an electric variable of the wind farm which has to be generated, wherein the farm control calculates an average increase of the real values of the electric variable for at least one time interval continuously, and compares it with a maximum value for the increase of the electric variable in the respective time interval, the farm control determines a proposal of a desired value for each predetermined time interval, based on a real value of the electric variable which was averaged continuously over the time interval, and in the case that the average increase in the at least one time interval is smaller than the maximum value in the corresponding time interval, the farm control determines a new desired value of the electric variable of the wind farm, with a selection of the desired value as the smallest of several proposals for a desired value.
    Type: Grant
    Filed: May 4, 2009
    Date of Patent: May 29, 2012
    Assignee: Nordex Energy GmbH
    Inventor: Mark Jurkat
  • Publication number: 20120123606
    Abstract: A system and method of regulating the voltage of the power supplied to a plurality of power customers via a power distribution system that includes low voltage power lines and medium voltage power lines is provided. A method may include measuring the voltage of a plurality of low voltage power lines at one or more customer premises in the power distribution system with corresponding voltage monitoring devices. The voltage monitoring devices transmit voltage data in real time to a remote computer system. The computer system receives the real time voltage data of the voltage measured from the voltage monitoring devices. The computer system compares the real time voltage data with a first threshold value; and if the real time voltage data is beyond the first threshold value, transmitting a first voltage adjustment instruction to a voltage control device configured to adjust the voltage supplied to a low voltage power line.
    Type: Application
    Filed: January 23, 2012
    Publication date: May 17, 2012
    Applicant: S&C ELECTRIC COMPANY
    Inventors: James D. Mollenkopf, Brian J. Deaver, SR., Joseph B. Herron, JR., David G. Kreiss
  • Patent number: 8179705
    Abstract: A power subsystem is actively optimized to improve total subsystem efficiency in a way that is responsive to changes in load requirements, power supply variations, and subsystem temperature variations. Detailed, multidimensional power loss models are developed for constituent devices which are then combined into a power subsystem containing a controller and circuity for measuring device operating parameters such as input and output voltage, output current, and temperature. Operating parameters are continually monitored, and set points are correspondingly changed based on the detailed power loss models to achieve maximum overall efficiency for the instantaneous operating state of the system.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: May 15, 2012
    Assignee: Power-One, Inc.
    Inventor: Alain Chapuis
  • Patent number: 8175755
    Abstract: Systems and methods for monitoring power devices that are connecting in a loop to a main power line are provided. A plurality of power devices that are connected in a loop to a power grid line may be provided. The loop may include a plurality of power lines. A disturbance within the plurality of power devices may be identified, and an impact of the identified disturbance on the plurality of power lines may be determined. A power output of one or more of the plurality of power devices may be adjusted based at least in part on the determined impact.
    Type: Grant
    Filed: November 18, 2009
    Date of Patent: May 8, 2012
    Assignee: General Electric Company
    Inventors: Andreas Kirchner, Enno Ubben
  • Patent number: 8159168
    Abstract: A method for estimating a rotor position in an electrical machine is provided. The method is applicable to electrical machines that have magnetic saliency. The method includes extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal and determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. The method also includes estimating the rotor position by applying the position error compensation to the extracted rotor position.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: April 17, 2012
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Jingbo Liu, Thomas Nondahl, Peter B. Schmidt, Semyon Royak, Mark H. Harbaugh
  • Patent number: 8155551
    Abstract: This disclosure provides power supply control methods and apparatus. According to one aspect of the disclosure, a method of operating a power supply operatively connected to a developer unit associated with a printing apparatus is disclosed. The method includes generating a modified output control signal as a function of stored gain and offset values associated with the power supply to generate a desired output voltage to drive the developer unit.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: April 10, 2012
    Assignee: Xerox Corporation
    Inventors: Hendrikus Adrianus Anthonius Verheijen, Henricus Johannes Maria Reijnders
  • Patent number: 8154892
    Abstract: Power output of a power generation system is controlled by measuring the output voltage of the system, dividing the measured voltage value into a target power value, then controlling the current provided by the generation system to the calculated value. In some embodiments the power generation system is connected to a grid.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: April 10, 2012
    Assignee: Arraypower, Inc.
    Inventor: Kent Kernahan
  • Publication number: 20120083940
    Abstract: There are provided a fuel cell system capable of reducing power consumption by inhibiting an unnecessary operation of a DC-DC converter, and a power control method therefor.
    Type: Application
    Filed: June 8, 2009
    Publication date: April 5, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroaki Mori, Kenji Umayahara
  • Publication number: 20120078436
    Abstract: Neural Network Loadflow (NNL) computation method is invented involving input vector composed of net nodal injection of real and reactive powers and diagonal elements of conductance and susceptance matrices multiplied by the squared voltage magnitude components of the flat-start normally used as initial solution estimate guess for loadflow solution by conventional NRL or SSDL methods. Training, and testing/validating input-output data sets are generated by applying uniform and non-uniform scaling factors applied to base case loads at PQ-nodes, resistance and reactance of transmission line branches. These scale factors are increased until loadflow solution by conventional methods such as Newton-Raphson Loadflow and Super Super Decoupled Loadflow methods diverge. Divergence of loadflow methods are due to node voltage, node angle, and numerical instabilities.
    Type: Application
    Filed: September 27, 2010
    Publication date: March 29, 2012
    Inventor: Sureshchandra B. Patel
  • Publication number: 20120065807
    Abstract: A control apparatus configured to control communication between an on-vehicle device and a device coupled to the on-vehicle device via a cable, the control apparatus comprising: a cable length detecting part configured to detect a length of the cable; and a power supply voltage controlling part configured to control, based on the length of the cable detected by the cable length detecting part, a power supply voltage in a connector connected to the device by changing a power supply voltage applied to a power supply line of the cable.
    Type: Application
    Filed: November 22, 2011
    Publication date: March 15, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Ryuichi YOKOTA, Yusuke OKU, Koji GAMO, Makoto FUJINO
  • Publication number: 20120065806
    Abstract: The present subject matter relates to methods and apparatus for measuring energy usage in an appliance, particularly a washing appliance. A display, that may be a home energy monitor, is associated with the appliance. The appliance may include an AC-DC power supply and a controllable inverter configured to supply power to a motor associated with the appliance. Real power consumption is calculated by a controller that may also be used to control the inverter and other operational aspects of the appliance and causes the calculated real power to be displayed on the display.
    Type: Application
    Filed: May 6, 2011
    Publication date: March 15, 2012
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Steven Michael Recio, Gautam Subbarao, Richard Dean Suel, II, Chad Michael Helms
  • Publication number: 20120053753
    Abstract: There is described a method of generating a power supply tracking a reference signal, comprising the steps of: filtering the reference signal; generating a first voltage in dependence on the filtered reference signal; generating a second voltage in dependence on the reference signal; and combining the first and second voltages to provide a power supply voltage.
    Type: Application
    Filed: November 4, 2009
    Publication date: March 1, 2012
    Applicant: NUJIRA LIMITED
    Inventors: Martin Paul Wilson, Gerard Wimpenny
  • Publication number: 20120046799
    Abstract: A device for monitoring and measuring the electrical and mechanical parameters of a power line conductor. Sensors of the device measure conductor temperature, the angle of inclination of the overhead conductor, current flowing in the conductor, and voltage to ground. The device has a low-power mode in which parameters of the power line conductor are not measured. Upon detecting a change in an electrical or mechanical value of the power line conductor, the device measures parameters of the power line conductor for a predetermined length of time before returning to the low power mode.
    Type: Application
    Filed: April 29, 2010
    Publication date: February 23, 2012
    Inventors: Paul Alan Alex, Duncan Breese, Larry Fish, Charles Lipsky, Chunchuan Xu
  • Publication number: 20120035780
    Abstract: An intelligent power saving system, disposed between a Utility Power Supply and at least a load, comprising: at least an energy storage device; at least a power supply line, connected to said Utility Power Supply and said load; at least an energy-storage-device-parallel-connection circuit, connecting said energy storage device electrically to said power supply line; and a power monitor, connected electrically to said Utility Power Supply, said energy storage device, and said energy-storage-device-parallel-connection circuit, thus determining whether said energy storage device is required to join in providing power to said load through said energy-storage-device-parallel-connection circuit, thus regulating percentage of total power supplied by said Utility Power Supply, preventing overload of said Utility Power Supply, hereby saving expense of the electric utility bills.
    Type: Application
    Filed: August 9, 2010
    Publication date: February 9, 2012
    Applicant: PHOENIX SILICON INTERNATIONAL CORPORATION
    Inventor: Chin-Chou CHEN
  • Publication number: 20120029723
    Abstract: A power plant for providing electric power to a power grid includes energy sources; power conditioning units and a controller configured to cause power provided to the grid to have selected electrical characteristics. The controller is in high speed real-time communication with the power conditioning units and programmed to provide instructions to the power conditioning units.
    Type: Application
    Filed: October 6, 2011
    Publication date: February 2, 2012
    Applicant: American Superconductor Corporation
    Inventors: Perry S. Schugart, William Vareka, Narendra Reddy
  • Publication number: 20120022714
    Abstract: A method and apparatus of operating a controller usable for operating a wind turbine is provided. The wind turbine includes a voltage converter being connectable to a power grid via a filter arrangement. The method includes determining a line voltage and adding the determined line voltage to the output of the voltage converter with a time delay. The time delay is adjusted such that resonant effects occurring at the filter arrangement are decreased.
    Type: Application
    Filed: June 23, 2011
    Publication date: January 26, 2012
    Applicant: VESTAS WIND SYSTEMS A/S
    Inventor: Eng Kian Kenneth SNG
  • Publication number: 20120022713
    Abstract: Embodiments of the present invention provide power flow analysis and may process electrical power distribution system data in real time to calculate load, current, voltage, losses, fault current and other data. The power flow analysis system may include a detailed data model of the electrical power distribution system, and may accept a variety of real time measurement inputs to support its modeling calculations. The power flow analysis system may calculate data of each of the three distribution system power phases independently and include a distribution state estimation module which allows it to incorporate a variety of real time measurements with varying degrees of accuracy, reliability and latency.
    Type: Application
    Filed: January 12, 2011
    Publication date: January 26, 2012
    Inventors: Brian J. Deaver, SR., Parag A. Parikh
  • Patent number: 8099199
    Abstract: There is provided a digital controller which can generate no oscillation even if sensing a load side and enables control of supplying a desired voltage to the load. In an power amplifier which supplies an output voltage vo to the load connected via a load connecting line, a load voltage vL and the output voltage vo are periodically sampled to calculate a manipulating variable ?1 from the output voltage vo, the load voltage vL and an arbitrary target value r. Based on the manipulating variable ?1 calculated, a control signal is output to the power amplifier. As a result, when connecting an LC filter with a load device 9 of the power amplifier intended for a control target and besides the load connecting line is long, a robust digital controller without generating oscillation even if sensing the load side is performed can be realized.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: January 17, 2012
    Assignee: TDK-Lameda Corporation
    Inventors: Eiji Takegami, Kazushi Watanabe, Satoshi Tomioka, Kouji Higuchi, Kazushi Nakano, Tatsuyoshi Kajikawa
  • Patent number: 8095245
    Abstract: A system and computer-implemented method for dispatching thermal energy and generating power in a solar power generating plant. The system includes a computer processor, computer readable medium, and control logic stored on the computer readable medium to direct the operation of the processor. The processor generates an optimized thermal energy dispatch schedule which controls operation of the generating plant by performing a combination of direct thermal energy and indirect thermal energy storage simulations to maximize operating revenues.
    Type: Grant
    Filed: July 29, 2009
    Date of Patent: January 10, 2012
    Assignee: Lockheed Martin Corporation
    Inventors: Rao Y. Mannepalli, Paul D. Albertelli
  • Patent number: 8090480
    Abstract: A mechanism for managing energy consumption of electrical devices within a home or building. Energy usage data is collected for a first electrical outlet connected to an unidentified electrical device in a facility. A pattern of energy usage is determined from the energy usage data collected at the first electrical outlet. The pattern of energy usage of the first electrical outlet is then compared against known patterns of energy usage for one or more other electrical outlets. Responsive to identifying a match between the pattern of energy usage of the energy usage data collected at the first electrical outlet and a known pattern of energy usage of a second electrical outlet in the one or more other electrical outlets, the electrical device connected to the first electrical outlet is identified as the same electrical device that is associated with the known pattern of energy usage of the second electrical outlet.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: January 3, 2012
    Assignee: International Business Machines Corporation
    Inventors: Sara Carlstead Brumfield, Xiaoping Chen, Tara Leigh Marshburn, Sandra Lee Tipton
  • Publication number: 20110313591
    Abstract: A method for controlling a power production entity is provided. The method includes generating a plurality of electric power signals by a plurality of power production entities, measuring a plurality of power levels of the plurality of power signals, modifying the plurality of power signals, supplying the plurality of modified power signals at a common node, and adjusting an operation voltage of at least one power production entity of the plurality of power production entities based on the plurality of measured power levels such that a power loss of the power signals caused by the modifying and/or supplying is minimized. Also a system for controlling a power production entity is described.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 22, 2011
    Inventors: Björn ANDRESEN, Per EGEDAL, Dragan OBRADOVIC
  • Patent number: 8078332
    Abstract: Methods are provided for managing high or low voltage conditions from selected areas of a power system of a utility company. Rubber-banding or lassoing is used to select geographic areas. Potential low or high voltage situations are identified in the selected geographic areas. Geographic displays are overlayed with superimposed VAR reserves to create overlayed geographic displays for the selected geographic areas. The overlayed geographic displays are used to identify potential low or high voltage instances in the selected geographic areas.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: December 13, 2011
    Assignee: Areva T & D, Inc.
    Inventors: Gennaro Castelli, Michael Hackett, Michael Quinn Howard, Lawrence Edmund Jones, HulChu Su Shung, Heath Daniel Brand
  • Patent number: 8078326
    Abstract: Control devices for configuring heating, ventilating, air conditioning, and cooling (HVAC) systems are provided. The control devices are designed to detect operational parameters of units within HVAC systems and present system configurations consistent with the detected parameters. In response to user selection of a system configuration, the control device may apply the system configuration to the HVAC system and may reconfigure settings of control circuits within system units. The system configurations presented by the control device may correspond to wiring diagrams that are familiar to service technicians. Methods of configuring HVAC systems with the control devices are also provided.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 13, 2011
    Assignee: Johnson Controls Technology Company
    Inventors: Greg R. Harrod, Brian D. Rigg, Nathan T. Ostrye, Jedidiah O. Bentz
  • Publication number: 20110295441
    Abstract: A digital control device for a parallel PMOS transistor board, includes: an operative memory for digitally storing error data between a target voltage and a setpoint voltage as well as control data, each datum being provided with a time marker, a digital selected order filter (36) for computing setpoint incrementation data from error data in the operative memory selected based on input error data, and for storing the input error data with a corresponding time marker in the operative memory, and a control computer (38) for computing new control data from the control incrementation data and control data in the operative memory selected based on input error data and for storing the new control data in the operative memory.
    Type: Application
    Filed: December 17, 2009
    Publication date: December 1, 2011
    Applicants: INSTITUT POLYTECHNIQUE DE GRENOBLE, Centre National De La Recherche Scientifique (C.N.R.S)
    Inventors: Carlos Canudas De Wit, Carolina Albea Sanchez
  • Patent number: 8068937
    Abstract: The disclosed power distribution system regulates the transfer of energy from a source 1 to a load 3. Source Controller 5 on the source side closes Disconnect Device 7 and monitors the transfer of a pulse or “packet” of energy to the load side. A Load Controller 9 on the load side communicates the amount of energy received at the load back to the source controller via Communication Link 11. If it is confirmed that the energy received on the load side corresponds to that sent by the source side, another energy packet is sent. If the energy received does not correspond with that sent by the source side, energy transfer is stopped, indicating a system fault or safety hazard. The energy content of a single packet is kept small, such that if it is not properly delivered, it can not cause damage to equipment or harm personnel.
    Type: Grant
    Filed: February 4, 2009
    Date of Patent: November 29, 2011
    Inventor: Stephen Spencer Eaves
  • Publication number: 20110276195
    Abstract: The plant comprises: a DC-voltage electric power source (3), whose operating conditions vary as a function of at least one uncontrollable quantity, for each value of the uncontrollable quantity the source presenting a characteristic curve of the supplied power as a function of a controlled quantity, wherein each characteristic curve presents a maximum for an optimal value of said controlled quantity; a power conditioning circuit (5); a regulation loop (9) to adjust the controlled quantity maximizing the power supplied by the source when said uncontrollable quantity varies. The regulation loop is de- signed in such a way as to determine whether, for the actual value of said uncontrollable quantity, the actual value of the controlled quantity (V.in) is greater or lower than the optimal value and to generate a regulation signal (V.in-REF) to modify the actual value of the controlled quantity towards the optimal value.
    Type: Application
    Filed: January 7, 2009
    Publication date: November 10, 2011
    Applicant: Power-One Italy S.P.A.
    Inventors: Sauro Macerini, David Martini, Silvio Scaletti
  • Publication number: 20110270463
    Abstract: The invention is concerned with a device and a method for controlling an inverter associated with a power source, which typically will be a distributed power source. The role of an inverter is to modulate the electrical power output, e.g. to provide a three phase AC electrical output at suitable voltage, where the output is to be supplied to a conventional power distribution, grid. The invention involves modelling the behaviour of a synchronous electrical generator. Variables represent the angular position and rotational speed of the virtual rotor (14) of this virtual synchronous generator. The torque electromagnetically exerted on the rotor is calculated from a measured inverter output current, and from a variable representing excitation current in the rotor.
    Type: Application
    Filed: October 29, 2009
    Publication date: November 3, 2011
    Inventors: George Weiss, Qing-Chang Zhong
  • Patent number: 8050804
    Abstract: An electronic module compares the output voltage of a solar panel to an expected value and controls the power demand from the solar panel such that the output voltage does not vary from the expected value by more than a predetermined value. The predetermined value may be determined by correcting a room temperature value for the temperature dependence of the photodiodes comprising the solar panel and manufacturing tolerance.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: November 1, 2011
    Assignee: Array Converter, Inc.
    Inventor: Kent Kernahan
  • Publication number: 20110264292
    Abstract: An uninterruptable power supply (UPS) designed to switch power inputs between an alternating current mode and a battery mode by adjusting the amplitude and/or frequency windows of the input voltage so that the uninterruptible power supply accepts the unstable voltage and/or frequency. This prevents the uninterruptible power supply to switch back to the battery mode during a transfer time between the battery mode and the AC mode. The uninterruptable power supply includes a control circuit. The control circuit modifies the monitored value and/or actual amplitude and/or the frequency window when unstable amplitude and/or an unstable frequency are detected at the input terminal of the input voltage.
    Type: Application
    Filed: April 27, 2010
    Publication date: October 27, 2011
    Applicant: TOSHIBA INTERNATIONAL CORPORATION
    Inventors: Yoichi Morishima, David M. Westmoreland
  • Publication number: 20110264299
    Abstract: A system and method for managing power uses a power meter that is electronically connected to a first point on a multiphase power distribution system to measure power information at that point. It determines harmonic distortion and true power factor correction based on the power information, and then determines configuration information for an active filter. The configuration information is send to one or more active filter to adjust harmonic distortion and true power factor correction on a second point in the distribution system.
    Type: Application
    Filed: April 21, 2011
    Publication date: October 27, 2011
    Applicant: SIEMENS INDUSTRY, INC.
    Inventor: George A. Mazzoli
  • Patent number: 8046111
    Abstract: Disclosed are a system and method with a cooperative control algorithm that can appraise voltage stability of a power system in cooperation with a supervisory control and data acquisition (SCADA)/emergency management system (EMS) for cooperative control on multiple parallel flexible alternating current transmission systems (FACTS) to enhance voltage stability, and that can calculate individual operation points of the FACTS.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: October 25, 2011
    Assignee: Korea Electric Power Corporation
    Inventors: Byung Hoon Chang, Yong Hak Kim, Soo Yeol Kim, Jong Su Yoon, No Hong Kwak
  • Patent number: 8041465
    Abstract: A voltage control arrangement for a system of multiple windfarms with transmission lines. Voltage is regulated at a point of regulation on the system, such as a high voltage substation or other system bus. Regulation is achieved at the point of regulation by sensing the voltage, comparing to a reference voltage, and adjusting the reactive power output of the wind turbines and other equipment in the system. The regulation point may be shifted to another point if needed to respect voltage limits at that points of the system after attempting to shift reactive load to restore voltage within limits at the other points in the system. The reference voltage may be adjusted to minimize losses for the system of multiple windfarms and transmission lines. A loss optimizing algorithm is applied to the combined multiple windfarm and transmission line to shift reactive load among local windfarms to minimize losses and to shift reactive load among individual wind turbines within an individual windfarm.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: October 18, 2011
    Assignee: General Electric Company
    Inventors: Einar V. Larsen, Reigh A. Walling, Kara Clark
  • Publication number: 20110245990
    Abstract: The present invention relates to a system and a method for connecting and/or interfacing a converter, such as a switched mode converter, to an electrical power grid. The invention furthermore relates to control of the converter. The present invention facilitates that the point of common coupling (PCC) between a utility grid and a converter is provided at the converter output. This facilitates that a converter, and thereby an electrical power source, may be connected to an electrical power grid without use of an inductor, such as a reactor.
    Type: Application
    Filed: October 28, 2009
    Publication date: October 6, 2011
    Applicant: Technical University of Denmark
    Inventor: Tonny Wederberg Rasmussen
  • Publication number: 20110231029
    Abstract: Power feeding is performed in a non-contact manner from a power feeding device to an electrical powered vehicle by resonance of a primary self-resonant coil of the power feeding device and a secondary self-resonant coil of the electrical powered vehicle through an electromagnetic field. The electric power received by the secondary self-resonant coil is rectified by a rectifier, and voltage-converted by a DC/DC converter to be supplied to a power storage device. A vehicle ECU controls the DC/DC converter such that the voltage between the rectifier and the DC/DC converter attains a target voltage.
    Type: Application
    Filed: September 25, 2008
    Publication date: September 22, 2011
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Shinji Ichikawa, Taira Kikuchi
  • Patent number: 8010815
    Abstract: A user may invoke energy savings in the operation of a computational device performing a processing task. The device performs the processing task in the invoked energy savings mode and determines an energy amount expended by the device in performing the processing task in the energy savings mode, creating a net energy savings value as a difference between the energy amount expended and a standard energy expenditure amount predicted as required for the computational device to perform the processing task in high-performance mode. The device displays the net energy savings value to the user, with the user continuing the invoking of the energy savings mode or engaging another performance mode for the computational device as a function of the displaying.
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: August 30, 2011
    Assignee: International Business Machines Corporation
    Inventors: Rick A. Hamilton, II, Brian M. O'Connell, Clifford A. Pickover, Keith R. Walker
  • Patent number: 7996116
    Abstract: A method of monitoring voltage stability within an electrical power system comprises the steps of establishing a dynamic power system stability margin based on an operating characteristic of the power system; indicating that the power system has become unstable when the dynamic power system stability margin falls below a predetermined value; and initiating dynamic load shedding and/or restoration depending on stability margin.
    Type: Grant
    Filed: December 28, 2007
    Date of Patent: August 9, 2011
    Assignee: Areva T & D UK Limited
    Inventors: Andrzej Wiszniewski, Waldemar Rebizant, Andrzej Klimek
  • Publication number: 20110190959
    Abstract: Even in a case where a rapid variance is demanded as to the input voltage of a converter and the output terminal voltage of a fuel cell, stable converter control is realized. On judging that the change ratio of the demand power of a fuel cell exceeds a set threshold value, a controller executes converter stabilization processing. First, the controller controls a battery converter so that an input voltage of an inverter becomes a set target input voltage. Then, after the input voltage of the inverter reaches the target input voltage, the controller controls an FC converter so that an output terminal voltage of the fuel cell becomes a set target output terminal voltage.
    Type: Application
    Filed: September 28, 2009
    Publication date: August 4, 2011
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kota Manabe
  • Publication number: 20110172847
    Abstract: An energy harvesting system includes: an energy harvesting unit for converting energy from a natural energy source into an electrical power signal; a power point tracking unit including a current tracing module capable of detecting a current of the electrical power signal, and a boundary control module; a microcontroller including a voltage detecting module capable of detecting a voltage of the electrical power signal, and a computing module for determining a maximum power point with reference to the voltage and the current of the electrical power signal, the boundary control module generating a switch control voltage signal with reference to the maximum power point; a storage unit capable of storing energy; and a pulse frequency modulation regulator for converting the electrical power signal into an intermediate signal with reference to the switch control voltage signal for subsequent storage of energy of the intermediate signal in the storage unit.
    Type: Application
    Filed: June 4, 2010
    Publication date: July 14, 2011
    Inventors: Chien-Ying Chen, Pai-Hsiang Chou
  • Publication number: 20110169461
    Abstract: A system, method and product for modifying the volt-ampere reactive (VARs) in a power distribution system is provided. In one embodiment, the method includes determining the VARs at a location on the power distribution system and based on the determined VARs, determining whether to modify the VARs. If it is determined to modify the VARs the method includes identifying a plurality a capacitor banks connected to a power line and from the identified plurality of capacitor banks, generating a list of eligible capacitor banks that satisfy inclusion criteria. If the list of eligible capacitor banks includes at least one capacitor bank the method includes selecting a capacitor bank from the list of eligible capacitor banks and transmitting a switching command for the selected capacitor bank.
    Type: Application
    Filed: January 20, 2010
    Publication date: July 14, 2011
    Inventor: Brian J. Deaver, SR.
  • Publication number: 20110160930
    Abstract: A local power converter may include a controller to manipulate the operating point of a local power converter to cause the power point tracking feature of a central power converter to operate at a point determined by the controller. In some embodiments, the controller can manipulate the operating point of the local power converter by alternating between at least two modes. In some other embodiments, the controller can manipulate the operating point of the local power converter to provide a substantially constant slope. In some other embodiments, the controller can maintain a substantially constant impedance ratio. In some other embodiments, the controller enables perturbations from the power point tracking feature of the central power converter to reach the power source.
    Type: Application
    Filed: December 17, 2010
    Publication date: June 30, 2011
    Applicant: AZURAY TECHNOLOGIES, INC.
    Inventors: Robert Batten, Vincenzo DiTommaso, Gary B. Baker, Henry F. Pruett, Adam Heiberg, Triet Tu Le, Edward Gee
  • Publication number: 20110153105
    Abstract: A home appliance includes an electronic controller with a trigger port which starts an operating cycle for the home appliance in response to a signal received on the trigger port that indicates availability of an alternative resource.
    Type: Application
    Filed: December 21, 2009
    Publication date: June 23, 2011
    Applicant: BSH HOME APPLIANCES CORPORATION
    Inventors: Ralf Winkler, Christian Wolf
  • Publication number: 20110153113
    Abstract: The invention concerns a method, device and computer program product for controlling a voltage source converter (16; 20) connected to a power grid (12; 24). The device (25; 26) includes a first input for receiving at least one detected electrical property (E, i) of an interface between the grid and the voltage source converter, and a control entity (27; 28) arranged to control the voltage source converter (16; 20) through using a control signal (vREF,TR) obtained through using a mapping of an electrical model of a non-salient synchronous machine onto an electrical model of the voltage source converter and through applying the detected electrical property of the interface between the grid and the voltage source converter in said mapped model, where the electrical model of the non-salient synchronous machine reflects the electrical dynamics of this synchronous machine.
    Type: Application
    Filed: August 26, 2008
    Publication date: June 23, 2011
    Inventor: Lennart Harnefors
  • Patent number: 7966101
    Abstract: The phase and time information of a voltage at a power supply outlet is detected at points, and sent to a data server. With one end of a system used as a phase angle reference, the data server observes phase differences at another end, and at a center. The data server then extracts an inter-system fluctuation component from an obtained fluctuation, and constructs an expanded combined vibration model for data sets obtained through first- and second-order differentiations of the component. The expanded combined vibration model is obtained by expanding a combined vibration model to include a known model of a PSS provided for a generator of interest. Time-series data regarding state variables of the PSS at the time of construction of the expanded combined vibration model are obtained, and PSS parameters are determined directly therefrom by the expanded combined vibration model, thereby achieving stabilization of dominant modes.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: June 21, 2011
    Assignee: Kyushu Institute of Technology
    Inventors: Yasunori Mitani, Masayuki Watanabe
  • Patent number: 7957847
    Abstract: Voltage regulating systems are provided that adjust their output control signals in response to feed-forward information that is indicative of deterministic changes in the load current. A feed-forward circuit provides a feed-forward signal in response to an input signal generated from a source that is external to the voltage regulating system. The voltage regulator systems can proactively respond to the predictive information by adjusting their output, thereby improving the regulation tolerance to dynamic loading. As an example, the feed-forward information can include signals indicating multiple deterministic events that affect the load. Signals from multiple events can be summed together to generate a feed-forward term. As another example, the voltage regulating systems can be responsive to feedback information and feed-forward information from internal to the regulator, in addition to external deterministic information.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: June 7, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: James Eddy Donaldson, Bryan Scott Rowan
  • Publication number: 20110130889
    Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the p
    Type: Application
    Filed: September 17, 2010
    Publication date: June 2, 2011
    Inventors: Sayed Ali KHAJEHODDIN, Masoud Karimi GHARTEMANI, Praveen JAIN, Alireza BAKHSHAI