With Harmonic Filter Or Neutralizer Patents (Class 307/105)
  • Publication number: 20100052432
    Abstract: The invention is directed to a method and an arrangement for harmonic wave suppression in AC voltage-operated PTC heaters in which a harmonic component which is generated in the current of the PTC heater and which contains predominantly the third harmonic of the heating current is compensated by the superposition of correction signals. It is the object of the invention to find a novel possibility for a simple and robust suppression of harmonic waves in AC voltage-operated PTC heaters in which the permissible limiting values for harmonic distortion are not exceeded as a result of changes in heating output. This object is met according to the invention in that a voltage modulation is generated in a voltage modulator (4) arranged in series with the PTC heater (3), wherein a defined partial amplitude attenuation of the sinusoidal supply voltage (U1) is carried out as voltage modulation for suppressing the third harmonic in the heating current (I2) of the PTC heater (3).
    Type: Application
    Filed: August 27, 2009
    Publication date: March 4, 2010
    Inventors: Klaus SEIDLER, Joerg Engelhardt, Lennard Janiak
  • Publication number: 20100045109
    Abstract: An AC power distribution unit for coupling AC power having a fundamental frequency to a plurality of electrical loads has an enclosure. A power input feed is retained by the enclosure for coupling to a source of the AC power. A plurality of power output feeds is retained by the enclosure for coupling to the plurality of electrical loads. A harmonic mitigation module is retained in the enclosure and is connected in series between the power input feed and the plurality of power output feeds. The harmonic mitigation module bilaterally reduces harmonic current distortion above a predetermined frequency between the power input feed and the plurality of power output feeds.
    Type: Application
    Filed: November 2, 2009
    Publication date: February 25, 2010
    Inventor: Ullrich Joseph Arnold
  • Publication number: 20100001588
    Abstract: A new multi-function shunt active filter has been successfully implemented. The proposed decoupler and cascade controller provide a simple solution to power factor correction, reduction of harmonics loads and load balancing. The mathematical burden of resolving the load current to fundamental and harmonics is not required. The decoupler and controller can easily be implemented using low-cost analogue devices.
    Type: Application
    Filed: July 7, 2008
    Publication date: January 7, 2010
    Applicant: The Hong Kong Polytechnic University
    Inventors: Kai Ming Tsang, Wai Lok Chan
  • Publication number: 20090309425
    Abstract: Three single-phase transformers having primary sides connected in a delta connection and the secondary sides connected in a series-delta connection. Each power line is connected through a fused disconnect to two primary terminals, each primary terminal on a different transformer. A second terminal on the secondary side of the first phase transformer is connected to a first terminal on the secondary side of the third transformer through a non-inductive grid resistor. The second terminal on the secondary side of the third transformer is connected to the first terminal on the secondary side of a second transformer. The second terminal on the secondary side of the second transformer is connected to the first terminal on the secondary side of the first transformer. In this fashion, the secondary sides of each of the single-phase transformers are connected in series through a non-inductive grid resistor.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 17, 2009
    Inventors: Daniel Princinsky, William Hinton
  • Publication number: 20090302689
    Abstract: This is a harmonic absorber (14) for eliminating the harmonics occurring due to unbalanced loads in a network transformer (1), a power factor correction system (6) to correct the cos ? value of the system to which it has been connected and an electrical system comprising electrical loads (7), and it contains at least one harmonic hole circuit (13), which consists of power reactance inductors (13.1) and power capacitors (13.2), and a harmonic separating circuit (12), which separates the harmonics existing in the network from the other components in the network and then, in order to achieve the elimination of each individual harmonic achieved in this manner, applies them to the mentioned hole circuit (13).
    Type: Application
    Filed: January 29, 2007
    Publication date: December 10, 2009
    Inventor: Kemal Isleyen
  • Patent number: 7629786
    Abstract: The invention is a harmonics reduction device for three-phase poly-wire power lines, which can more reliably eradiate harmonics current applied to an electric power system via a neutral line. The invention comprises an electric power system having three-phase poly-wire power lines in order to supply alternating-current (AC) power voltage to a load; a zigzag transformer in which windings connected with three-phase lines in the electric power system are wound through first and second legs, second and third legs, and third and first legs of a core having three legs, respectively, while varying direction of each magnetic flux, and an intermediate point of each winding is commonly connected with a neutral line of the electric power system and that of the load; and an open delta connection portion in which an winding connected with the neutral line of a load side is wound through the three legs so as to be connected with a neutral line of the electric power system.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: December 8, 2009
    Inventor: Sung Ho Lee
  • Patent number: 7616087
    Abstract: An installation for transmission of electric power via a high-voltage ac voltage line between two switchgear units located at a large distance from each other. For the transmission of the electric power, the ac voltage line includes at least one extruded cable with an inner electric conductor, an insulating layer of a solid material surrounding the conductor, and an outer screen layer located at ground potential. The installation also includes one or more inductors located along the extent of the cable between the switchgear units and integrated into the cable. The inductors are connected between the conductor of the cable and ground for reactive shunt compensation.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: November 10, 2009
    Assignee: ABB AB
    Inventors: Per Halvarsson, Claes Bengtsson, David Larsson, Johan Karlstrand
  • Patent number: 7609535
    Abstract: A power supply electromagnetic interference (EMI) filter circuit and technique. In one embodiment, a method of filtering EMI in a power supply includes rectifying an AC signal from an AC source, smoothing the rectified AC signal with a bulk storage capacitor to provide a DC output as an input to a power conversion circuit and filtering the EMI generated by the power conversion circuit from reaching the AC source by using the bulk capacitor and one or more inductors in combination with the AC source capacitance as an EMI filter. In one embodiment the method also includes the use of one or more of the inductors as a fusing element.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: October 27, 2009
    Assignee: Power Integrations, Inc.
    Inventor: Balu Balakrishnan
  • Publication number: 20090243398
    Abstract: Systems and methods for reducing harmonic distortion in a power system resulting from non-linear loading on the power system. The power at an interface with a power source is measured, and then distortion in the waveforms of the supplied power is identified. Cancellation signals which cancel all or part of the distortion are then generated and injected at the interface. In one embodiment, the power is sampled to determine the waveform, and then a Fast Fourier Transform is performed on the waveform to convert it to the frequency domain. Harmonics of the fundamental frequency can then be identified, and conjugates of the harmonics generated. An inverse Fast Fourier Transform is performed on the conjugates to generate a signal which is amplified to produce the cancellation signal.
    Type: Application
    Filed: March 28, 2008
    Publication date: October 1, 2009
    Inventors: Tom G. Yohanan, John M. Leuthen, Jerald R. Rider, Michael C. Underwood
  • Publication number: 20090212641
    Abstract: A method for operating a converter circuit is disclosed. Such a converter circuit has a converter unit with a multiplicity of actuatable power semiconductor switches and is connected to a three-phase electrical AC mains system and in which the actuatable power semiconductor switches are actuated by means of an actuation signal (SA) formed from a control signal (SR), and the control signal (SR) is formed by adjusting an H-th harmonic component of system currents (iNH) to a system current setpoint value (iNHref), wherein H=1, 2, 3 . . . . For the purpose of reducing a harmonic component in the system voltages, the system current setpoint value (iNHref) is formed by adjusting the absolute value of an H-th harmonic component of the system voltages (uNH) to the absolute value of a prescribable system voltage setpoint value (uNHref). An exemplary apparatus carries out the method.
    Type: Application
    Filed: February 20, 2009
    Publication date: August 27, 2009
    Applicant: ABB SCHWEIZ AG
    Inventors: Beat Ronner, Osvin Gaupp
  • Publication number: 20090212640
    Abstract: A device for connection to an impedance having a mainly inductive character. The device comprises a reactive element. Furthermore, the device is provided with inputs for inputting output signals of electric inverters for parallel supply and at least one output for connection to a supply terminal for a phase of the impedance, such that the device is composed to substantially filter out a high-frequency differential component of at least two output signals during use.
    Type: Application
    Filed: November 20, 2006
    Publication date: August 27, 2009
    Applicant: ATLAS COPCO AIRPOWER N.V.
    Inventor: Gerd Terörde
  • Publication number: 20090134714
    Abstract: A system and a method for compensating harmonic components or a reactive power of an electrical network. The system comprises a measurement unit (1) configured to measure an electrical quantity to be compensated, a control unit (2) configured to determine harmonics contents or a reactive power need of the measured electrical quantity to be compensated as well as to determine, as relative values, desired values corresponding with the harmonics to be compensated or the reactive power to be compensated, one or more compensation units (5, 6) configured, responsive to the desired values provided by the control unit (2), to generate harmonic components or a reactive current according to the desired values given as relative values, and a communications connection (3) configured to communicate the desired values determined by the control unit (2) to the compensation units (5, 6).
    Type: Application
    Filed: November 26, 2008
    Publication date: May 28, 2009
    Applicant: ABB Oy
    Inventors: Antti TARKIAINEN, Tero Viitanen
  • Patent number: 7535125
    Abstract: A harmonic current filter includes a first and second power system connectors and first and second load connectors, wherein the second power system connector is directly connected to the second load connector. The filter has a magnetically permeable core with three legs. A first line winding is connected between the first power system connector and the first load connector and is wound around one leg in a manner to produce magnetic flux having a given polarity. A capacitor and a first shunt winding are connected in series between the first power system connector and the second load connector. The first shunt winding is wound around another leg in a manner to produce magnetic flux having an opposite polarity.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: May 19, 2009
    Assignee: MTE Corporation
    Inventor: Todd A. Shudarek
  • Publication number: 20090121553
    Abstract: A single-phase electronic power-saving device includes at least one power-saving unit. The power-saving unit includes two ceramic piece capacitors, a safe capacitor, an inductor, a SCR, a first resistor, a second resistor, a live wire and a zero line; the two ceramic piece capacitors connected in series as a whole is connected in parallel with the safe capacitor to two terminals of which are connected the anode and the cathode of SCR, respectively; the anode of SCR is also connected to one terminal of the inductor, the branch composed of the first and the second resistors connected in series is connected in parallel so that one terminal of which is connected to one terminal of the inductor and the other is connected to the cathode of SCR; the gate of SCR is connected between the first and the second resistors.
    Type: Application
    Filed: August 16, 2005
    Publication date: May 14, 2009
    Inventor: Jia Yi Zhang
  • Patent number: 7485987
    Abstract: A power converting device includes a single-phase multiplex converter used as an active filter and a control device. The single-phase multiplex converter includes multiple single-phase inverters connected in series at AC output sides. Each of the single-phase inverters converts DC power fed from a DC power supply into AC power. The control device includes hysteresis comparators and controls output voltage of the single-phase multiplex converter by gradational output voltage control, based on the sum of selectively combined output voltages of the multiple single-phase inverters. The control device controls the single-phase multiplex converter so that an output current follows a harmonic compensation reference current, canceling harmonics leaking from a load to which the power converting device is connected.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: February 3, 2009
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Osamu Mori, Masaki Yamada, Akihiko Iwata
  • Publication number: 20090021083
    Abstract: The object of the invention is to implement a circuit arrangement, which in rated operation without resonance generates as little power loss as possible, but on suitable excitation effects a disproportionate asymmetrical damping, so that resonances and overvoltages associated with them are avoided. The object is attained by using a damping member 5a, b, c, which effects the damping in proportion to a primary circuit parameter. The advantage is the adaptive performance of a power grid filter equipped with the choke of the invention.
    Type: Application
    Filed: July 15, 2008
    Publication date: January 22, 2009
    Inventor: Roland Donner
  • Publication number: 20080309168
    Abstract: The invention relates to a method and to an arrangement for harmonic-wave suppression in AC voltage-operated PTC heaters, especially in frequency-stable and frequency-variable alternating-voltage networks in aerospace applications. The problem of harmonic-wave suppression for AC voltage-operated PTC heaters, in which the harmonic waves are suppressed by superimposing a correction current, which permits a simple and economical generation of the harmonic-wave suppression signal, is solved according to the invention by generating a correction current in a correction current circuit arranged parallel to the PTC heater using an ohmic resistor (4). The correction current is generated and additively superimposed exclusively for suppressing the third harmonic of the heating current of the PTC heater.
    Type: Application
    Filed: March 13, 2008
    Publication date: December 18, 2008
    Inventors: Klaus Seidler, Joerg Engelhardt
  • Patent number: 7465872
    Abstract: Photovoltaic power converter system including a controller configured to reduce load harmonics is provided. The system comprises a photovoltaic array and an inverter electrically coupled to the array to generate an output current for energizing a load connected to the inverter and to a mains grid supply voltage. The system further comprises a controller including a first circuit coupled to receive a load current to measure a harmonic current in the load current. The controller includes a second circuit to generate a fundamental reference drawn by the load. The controller further includes a third circuit for combining the measured harmonic current and the fundamental reference to generate a command output signal for generating the output current for energizing the load connected to the inverter. The photovoltaic system may be configured to compensate harmonic currents that may be drawn by the load.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: December 16, 2008
    Assignee: General Electric Company
    Inventors: Michael Andrew de Rooij, Robert Louis Steigerwald, Eladio Clemente Delgado
  • Patent number: 7453330
    Abstract: A line filter has a filter unit, which has an input and an output and also a current-compensated choke and a capacitance network. The choke has several phase windings on a common core. Each phase winding is connected in series with a phase conductor. The capacitance network has capacitors, which are each connected between a phase conductor and a neutral conductor. Another choke is provided in series to the neutral conductor, which is wound separately from the core.
    Type: Grant
    Filed: February 15, 2007
    Date of Patent: November 18, 2008
    Assignee: Epcos AG
    Inventors: Kurt Beil, Christian Paulwitz
  • Patent number: 7449799
    Abstract: A harmonic mitigating device for connection between a power distribution system and the load uses a magnetic shunt to control the levels of magnetic coupling between different elements of the device while providing all windings on a single core. This allows for the reduction or elimination of the harmonic MMF induced in the line winding of the device, and as a result the reduction of harmonic currents flowing into the power supply system; and the reduction of the line winding inductance, which in turn reduces the voltage boost of the device under the no-load conditions, reduces the voltage drop at full load conditions and increases the stability of the drive. The invention serves to reduce ripple level in rectifier outputs and buffers transient overvoltages, and a single configuration works with any rectifier type, including SCR bridges.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: November 11, 2008
    Assignee: 1061933 Ontario Inc.
    Inventors: Michael I. Levin, Anthony H. Hoevenaars, Igor V. Volkov
  • Patent number: 7446436
    Abstract: A number of wave correction filters are disclosed which respond to power surges or spikes outside the intended frequency and/or voltage for a load device. The circuits respond to such undesired frequencies and voltage levels by sensing and separating them from the desired voltage and frequencies and connecting the energy from such undesired voltages and/or frequencies to resistors where it is dissipated as heat. In this way, the resulting energy is prevented from distorting the input voltage to the load device. It is also retained in the filter and prevented from traveling through a ground connection to pollute other related circuits.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: November 4, 2008
    Assignee: Environmental Potentials, Inc.
    Inventors: Andrew Pickett, Theodore Thibault, Edward G. Price
  • Patent number: 7446435
    Abstract: A power system for providing an output power to a load is provided. The system comprises a generator configured to generate an alternating current input power and an power converter system coupled to the generator and configured to generate an output power and provide the output power to the load through at least one transformer. The system further comprises a converter control system coupled to the converter system and configured to drive the converter system in an interleaved pattern to reduce harmonic components in the output power and the alternating current input power.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: November 4, 2008
    Assignee: General Electric Company
    Inventors: Richard S. Zhang, Changyong Wang, Lei Li, James Patrick Lyons, Zhuohui Tan, Allen Michael Ritter
  • Publication number: 20080211315
    Abstract: In an electrical distribution system for supplying power from an AC source to an adjustable-speed drive connected in a single-phase manner, a device for substantially eliminating harmonic currents in the supply lines of said system. The device includes a completely-passive parallel resonant circuit having three passive electrical branches connected in parallel and also having an almost infinite impendence at a third harmonic frequency of a fundamental frequency of said AC source to prevent the formation of only said third harmonic frequency so that there is no third harmonic current to remove or dissipate as heat. The three passive electrical branches comprise a first branch consisting of a capacitor, a second branch consisting of a reactor, and a third branch consisting of a resistor. The parallel resonant circuit is electrically connected to at least one supply line.
    Type: Application
    Filed: February 13, 2008
    Publication date: September 4, 2008
    Inventor: Michael Z. Lowenstein
  • Patent number: 7405498
    Abstract: A multi-phase active filter includes a group of power cells electrically connected in a three-phase configuration, a precharging circuit, and a controller that controls the voltage delivered to the plurality of power cells. Each power cell includes an inverter having a pair of direct current (DC) terminals, at least one capacitor electrically connected in parallel with the inverter, and an energy dissipating circuit that is electrically connected in parallel with the inverter. The energy dissipating circuit of each power cell self-regulates DC voltage within the cell.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: July 29, 2008
    Assignee: Siemens Energy & Automation, Inc.
    Inventors: Mukul Rastogi, Peter Hammond, Stan Simms
  • Patent number: 7405919
    Abstract: A power supply circuit produces a supply voltage to be supplied to a microprocessor which is an integrated circuit. A transmission line type noise filter includes a signal input terminal, a signal output terminal and two ground terminals corresponding respectively to the signal input terminal and the signal output terminal. The transmission line type noise filter eliminates a high-frequency component of DC voltage applied to the signal input terminal and outputs it from the signal output terminal. A first power supply line pattern, formed on a printed-circuit board, connects an output terminal of the power supply circuit with the signal input terminal of the transmission line type noise filter. A second power supply line pattern connects the signal output terminal of the transmission line type noise filter with a power supply terminal of the microprocessor. A ground land pattern is connected with an external ground potential through via holes and makes a connection between the two ground terminals.
    Type: Grant
    Filed: June 22, 2006
    Date of Patent: July 29, 2008
    Assignee: Sony Computer Entertainment Inc.
    Inventor: Kazuaki Mitsui
  • Publication number: 20080174183
    Abstract: An active filter that can remove harmonic noises other than the fundamental wave in a system having many unspecified harmonics and can contribute to the stable operation of the system, and improvement in the quality of power is provided. Using the following power equation (1) for a single-phase circuit as a basic expression, an active power effective value P and a reactive power effective value Q are obtained by integration operation with an active power instantaneous value and a reactive power instantaneous value, an instantaneous voltage estimation value is calculated, the system side fundamental wave current is obtained based on these values, and then the system side fundamental wave current is subtracted from the load current to obtain compensation current as the output of the active filter.
    Type: Application
    Filed: June 28, 2007
    Publication date: July 24, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Kempei Seki
  • Publication number: 20080164767
    Abstract: An Op amp circuit is used to provide higher capacitance to a power network to remove unwanted high frequency components from the power signal. At the primary power line frequency, a lower capacitance is presented by the circuit.
    Type: Application
    Filed: January 5, 2007
    Publication date: July 10, 2008
    Inventor: Martin H. Graham
  • Publication number: 20080129122
    Abstract: A broad-spectrum harmonic filter is developed. This filter is to be connected in series ahead of the load which generates harmonics. This filter basically consists of 3 fixed elements, i.e. a series reactor and a shunt reactor in series with a capacitor. It can function to completely filter out 5th harmonic current in 3 phase systems (or 3rd harmonic current in single phase systems) and to reduce other harmonic components by high percentages say, typically close to 70%. Thus the portions of various harmonics flowing toward the electrical power source can be held within acceptable limits.
    Type: Application
    Filed: July 27, 2004
    Publication date: June 5, 2008
    Inventors: Luke Yu, Henry Yu
  • Patent number: 7378754
    Abstract: A three-phase filter has first, second, and third power source connectors and first, second, and third load connectors. A separate phase line filter is connected between each pair of power source and load connectors. Each phase line filter includes a line winding connected between the power source and load connectors for a phase line and includes a first shunt winding, resistor and capacitor connected in series between that load connector and the load connector for another phase line. The line and shunt windings for a given phase line filter are wound on a core in directions so that one winding produces magnetic flux having an opposite polarity to the magnetic flux produced by the other winding. The magnetic coupling of those windings, mitigates harmonic currents that otherwise flow in either direction between the power source and load connectors.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: May 27, 2008
    Assignee: MTE Corporation
    Inventor: Todd A. Shudarek
  • Patent number: 7368891
    Abstract: Charging time of a capacitor is shortened while avoiding erroneous firing due to distortion of a power supply voltage and sustaining an inrush current at a constant level. In the charge control method of a capacitor in a thyristor converter comprising a thyristor for rectifying an AC voltage, a CPU delivering an on/off control signal to a thyristor driver for driving the thyristor, a voltage detection sensor for measuring the AC voltage and the capacitor charging voltage, and the capacitor connected with a DC circuit, the AC voltage and the capacitor charging voltage are measured by means of the voltage detection sensor, differential voltage between the firing phase voltage of the thyristor and the capacitor charging voltage is determined, and the thyristor is fired only when the firing phase voltage of the thyristor becomes lower than a specified voltage determined from the differential voltage.
    Type: Grant
    Filed: January 30, 2006
    Date of Patent: May 6, 2008
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Hajime Takahashi, Kazuhiko Hiramatsu
  • Patent number: 7362162
    Abstract: The invention is directed to a network filter that comprises at least one phase input and a protective conductor in which each phase input is connected via a filter inductance to a corresponding phase output, in which the input side of each filter inductance is connected to the protective conductor via a filter capacitor, and in which an auxiliary inductance is connected between each filter capacitor and the protective conductor, permitting the inductances in the filter to be kept small, potentially realized by simply slipping a ferrite core over a conductor.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: April 22, 2008
    Assignee: EPCOS AG
    Inventors: Christian Paulwitz, Manfred Karasek
  • Patent number: 7336193
    Abstract: A device for monitoring a leakage current of a surge arrester has a measuring element for detecting a leakage current in a leakage current circuit. A filter assembly filters the leakage current in order to extract a third harmonic oscillation which is evaluated by an evaluation circuit with respect to the value thereof. The evaluation circuit delivers at least one warning signal to a display device. In a preferred embodiment, three display devices operating as a signaling light are provided. A power supply for the used circuits is obtainable by way of a transformer which extracts a necessary auxiliary zero-potential energy contained in the leakage current and with the aid of a main power supply unit connected to the transformer.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: February 26, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventors: Haiko Schillert, Matthias Schubert, Kai Steinfeld
  • Publication number: 20070296277
    Abstract: Disclosed relates to an electromagnetic interference (EMI) filter. Capacitance and resistance or inductance of an EMI filter, which includes a resistor and a capacitor or an inductor and a capacitor, can be controlled, such that a cutoff frequency can be freely controlled without manufacturing a separate EMI filter according to a characteristic of a desired cutoff frequency. Further, an intelligent EMI filter that can be applied to a surge protection device, which includes an ESD protection function as well as the EMI filter, is provided, such that a process can be simplified and costs can be reduced.
    Type: Application
    Filed: June 27, 2007
    Publication date: December 27, 2007
    Inventors: Kye Nam Lee, Young Jin Park, Jin Hyung Kim, Hyun Kyu Yang, Yoo Ran Kim
  • Patent number: 7301787
    Abstract: An active type harmonic suppression apparatus, connected in parallel to a power feeder, supplies a compensation current for injecting into the power feeder such that a utility current of a power source is approached to a sinusoidal wave. The control circuit retrieves a load current, a utility current, an output current of the power converter, a power source voltage and a voltage of the dc power capacitor for calculating and sending a reference signal of compensation voltage to a pulse-width-modulation circuit which generates switching signals for the power converter. Furthermore, the harmonic suppression apparatus can provide a fixed or variable reactive power.
    Type: Grant
    Filed: July 11, 2005
    Date of Patent: November 27, 2007
    Assignee: UIS Abler Electronics Co., ltd.
    Inventors: Chin-Chang Wu, Hung-Liang Chou, Ya-Tsung Feng, Wen-Pin Hsu, Yao-Jen Chang
  • Patent number: 7289888
    Abstract: A method for scheduling of periodic real time processes in an operating system, comprising the steps of defining a reference point in time for a periodic real time process, and scheduling the periodic real time process from the reference point in time. Preferably a future point in time is defined as the reference point in time at the start up of the operating system. The real time process is preferably a periodic control process during which a relative control point in time, counted from the beginning of the subsequent control cycle, is calculated during each cycle with absolute time correction counted from the reference point in time. The absolute time correction corresponds to the period of the periodic process multiplied with the number of passed control periods until the beginning of the subsequent control cycle, at which the absolute control point in time is calculated through an addition of the relative control point in time with the absolute time correction.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: October 30, 2007
    Assignee: Comsys AB
    Inventor: Jonas Persson
  • Patent number: 7262521
    Abstract: A method and apparatus is disclosed for providing a regulated voltage output from a variable voltage source, alternately using saturation control and cancelling control to regulate output.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: August 28, 2007
    Assignee: Pratt & Whitney Canada Corp.
    Inventors: Kevin Allan Dooley, Cameron Todd Walters
  • Patent number: 7245045
    Abstract: An active filter (4) for compensation of variations in an apparatus' (3) current consumption from a power grid (1) as a cause of variations in the apparatus electrical load, through active frequency filtering and dynamic compensation of reactive energy/current. For each of the power grid's phases (a, b, c) the active filter includes a transistor bridge (Ta, Tb, Tc) connected between each phase and a DC-link (7). The active filter includes a filter circuit of LCL-type, arranged to reduce disturbances on the power grid caused by the active filter itself. The active filter further includes a control device (9) for calculating, with a given working frequency (f), points in time at which the transistor bridges are set to reverse the current direction through the DC-link, and the filter circuit is preferably adjusted to that working frequency.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: July 17, 2007
    Assignee: Comsys AB
    Inventors: Peter Ström, Dan Liljengren
  • Patent number: 7233081
    Abstract: A power-supply device suppresses high harmonic waves, controls the flow of AC power, and minimizes adverse effects on a load that might otherwise be caused by a large surge of current into the load during the startup or stopping of the power-supply device. The power supply device includes a voltage supply unit 2 disposed in series between input and output terminals. This voltage supply unit functions to gradually lower the output-voltage level from a state of canceling the voltage across input terminals of the power supply device at the time of starting up the power-supply device, so that a gradual rise in the output voltage from the power-supply device is achieved. When the power-supply device is stopped, a gradual lowering of the output voltage from the power-supply device is obtained by gradually increasing the output voltage of the voltage supply unit so as to cancel the input voltage.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: June 19, 2007
    Assignee: Fuji Electric Systems Co., Ltd.
    Inventor: Hirokazu Tokuda
  • Patent number: 7200500
    Abstract: A method for determining an equivalent impedance of a transmission section of an electrical network, includes representing the transmission section as having at least two interfaces with other sections of the network. For each interface, a voltage phasor and a current phasor flowing through the interface are determined from simultaneously made measurements at the interfaces. From the phasors, the equivalent impedance is calculated. The required simultaneousness of the phasor measurements is achieved by means of Phasor Measurement Units (PMUs) that are synchronized via the Global Positioning System (GPS).
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: April 3, 2007
    Assignee: ABB Research Ltd
    Inventors: Mats Larsson, Christian Rehtanz, Marek Zima
  • Patent number: 7193869
    Abstract: A noise suppressor capable of achieving reduction in size and weight of devices is provided. The noise suppressor is a circuit for suppressing normal mode noise which is transmitted through a first current-carrying wire and a second current-carrying wire, and causes a potential difference between the current-carrying wires, and the noise suppressor includes a magnetic core including one magnetic material portion and another magnetic material portion magnetically coupled to the one magnetic material portion, and forming two magnetic loops so as to share the one magnetic material portion between them, an inductor including a first coil and a second coil which are wound around the one magnetic material portion so as to have an odd number of turns in total, and are inserted into and connected to the first current-carrying wire in series; and a capacitor having one end connected to a connecting point between the first coil and the second coil and the other end connected to the second current-carrying wire.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: March 20, 2007
    Assignee: TDK Corporation
    Inventor: Mitsunari Suzuki
  • Patent number: 7091704
    Abstract: A three-phase three-wire active power filter includes a dc power capacitor, a power converter, a filter inductor set, a reactive power compensating capacitor set, a combined capacitor/resistor filtering set and a control circuit. The dc power capacitor provides with a regulated voltage. The power converter includes a two-arm bridge power converter, and has a pair of ac terminals and a pair of dc terminals. A phase of the three-phase three-wire active power filter, without control of the power electronic switch set, directly connects with any one of the dc terminals. Consequently, the number of power electronic switches employed in the two-arm bridge power converter of the three-phase three-wire active power filter can be reduced.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: August 15, 2006
    Assignee: UIS Abler Electronics Co., Ltd.
    Inventors: Hung-Liang Chou, Chin-Chang Wu, Wen-Pin Hsu, Ya-Tsung Feng, Yao-Jen Chang
  • Patent number: 7092229
    Abstract: A device for an electrical power system having a nonlinear load. The circuit is connected in series with the nonlinear load and is tuned to the third harmonic of the power source frequency. The circuit substantially eliminates the harmonic currents and neutral currents located in the power system, and improves the power factor of the nonlinear load by optimizing the current drawn by the nonlinear load.
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: August 15, 2006
    Assignee: Harmonics Limited, Inc.
    Inventor: Michael Z. Lowenstein
  • Patent number: 7078831
    Abstract: An electric control system for a pulse width modulated inverter connected in parallel to an electricity distribution network for correcting or minimizing a voltage total harmonic distortion of the distribution network includes a sampler of the voltage of the electricity distribution network for obtaining samplings of the distribution network. The sampler preferably is an analog-to-digital converter. The system also includes a phase locked loop circuit that supplies a phase value of a period under examination, and a storage system for coupling the various samplings with the phase value obtained by the phase locked loop circuit.
    Type: Grant
    Filed: November 19, 2001
    Date of Patent: July 18, 2006
    Assignee: EDP S.R.L.
    Inventors: Vincenzo Ferraro, Emilio Ferraro
  • Patent number: 7061142
    Abstract: According to one embodiment of the invention, a method for providing power to a device coupled to a communications switch through a data line is provided. The method includes determining that the device includes a diode. The method also includes providing power to the device in response to the determination.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: June 13, 2006
    Assignee: Cisco Technology, Inc.
    Inventor: Robert A. Marshall
  • Patent number: 7054172
    Abstract: A method and structure for active power control of a power supply element coupled to an electronic circuit. The structure comprises a control element coupled to the electronic circuit, said control element comprising one or more of a phase detector, a counter, a level detector, a voltage controlled oscillator, and one or more transistive elements wherein the control element is operable to measure one or more oscillations of a power supply signal of the power supply element. The structure further comprises a stabilization element coupled to the control element and coupled to the circuit, comprising one or more capacitive elements, one or more transistive elements and one or more resistive elements, wherein said one or more capacitive elements, one or more transistive elements and one or more resistive elements are operable to mitigate one or more oscillations of the power supply signal of the power supply element.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: May 30, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Jason Harold Culler
  • Patent number: 7053505
    Abstract: An amplifying circuit, which generates a compensation current based on a detection result of a leakage current flowing between an AC power source for supplying power and a power converting circuit section, includes a main amplifier having transistors and a correction amplifier connected in parallel to the main amplifier. Capacitors are connected between each base of transistors, forming the main amplifier and the correction amplifier, and a ground line, and between an output terminal of the correction amplifier and the ground line, respectively, and an impedance ratio of these capacitors is adjusted, thereby adjusting an amplification ratio.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: May 30, 2006
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Mamoru Tsuruya
  • Patent number: 7026728
    Abstract: The system is intended to provide an isolated power supply for an electrical load. It contains a generator for producing a supply signal, and a transmission path having two separate branch elements. The first branch element is designed for transmission of the supply signal (S1) in the forward direction, and the second branch element is designed for transmission of the supply signal in the backward direction, so that this results in a closed circuit for the supply signal. The two branch elements contain means for isolation. The load can be supplied by the supply signal with an electrical power of at most 100 mW.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: April 11, 2006
    Assignee: Siemens Aktiengesellschaft
    Inventors: Siegfried Birkle, Stefan Hain
  • Patent number: 6985370
    Abstract: A parallel resonant circuit for removing noise and harmonic frequencies from the AC power source is connected directly in parallel to a power source with no intervening electrical components. The parallel resonant circuit is comprised of at least one inductor for drawing an inductive current that is substantially equal to but one hundred and eight degrees out of phase with at least one capacitor that draws a capacitive current. The capacitors and the inductors of the parallel resonant circuit are connected in parallel and may be tuned to the fundamental frequency of the power line.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: January 10, 2006
    Inventor: David Kerstetter
  • Patent number: 6958666
    Abstract: The invention provides a filter circuit comprising inductors (6, 15) and capacitors (11) interconnected to form filter stages, the capacitors (11) being distributed over at least two printed circuit cards (7, 8) disposed facing each other and spaced apart by a gap (H), at least one inductor (15) extending across the gap (H) between the cards and connected to both cards (7, 8). The invention also provides a power supply device equipped with such a filter circuit.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: October 25, 2005
    Assignee: Johnson Controls Automotive Electronics
    Inventors: Patrice Begon, José Picot
  • Patent number: 6940187
    Abstract: A controller (236) for an uninterruptible power supply (UPS) compensates for harmonic distortion in the output current (224,26,228). The controller also provides a control vector (230) also with input from the adaptation processor (234).
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: September 6, 2005
    Assignee: Northeastern University
    Inventors: Gerardo Escobar, Alex M. Stankovic, Paolo Mattavelli