Phase Patents (Class 361/85)
  • Patent number: 10509066
    Abstract: A device, in at least two measuring intervals, detects a respective operating state of at least one power converter of the motor vehicle, which is conductively connected to the traction energy store. The device further comprises a measuring device having a measuring terminal, which is conductively connected or connectable to least one DC voltage pole of an electric traction energy store of the motor vehicle, and a ground terminal which is conductively connected or connectable to a reference potential of the motor vehicle. The measuring device, in the at least two measuring intervals, respectively measures a conductance between the measuring terminal and the ground terminal. The device further comprises a calculation device, which determines the insulation resistances as a function of the at least two measured conductances and the at least two operating states detected.
    Type: Grant
    Filed: February 23, 2018
    Date of Patent: December 17, 2019
    Assignee: MAN TRUCK & BUS AG
    Inventors: Alexander Moertl, Markus Hubert, Stefan Soboll
  • Patent number: 10274529
    Abstract: A method of estimating a periodic voltage, such as an input voltage, of one of the phases of an electrical circuit with at least two phases including a voltage sensor for each of its phases, each voltage sensor being capable of outputting a signal representative of at least a part of period of the periodic voltage of the phase. The method including the following steps: measure the representative signal starting from the voltage sensor; amplify the representative signal by a gain determined in the absence of an electrical fault in the circuit and based on a reference voltage common to all phases in the electrical circuit (1); use the amplified representative signal to estimate the periodic voltage. A device for estimating a voltage and an electrical circuit including such a device.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: April 30, 2019
    Assignee: SCHNEIDER ELECTRIC INDUSTRIES SAS
    Inventors: Bernard Drouere, Julien Mecreant
  • Patent number: 10263413
    Abstract: A single-phase or multi-phase feed line is connected to a charging connection of the charging station, via which feed line the charge current flows to the charging connection of the charging station regardless of the load capacity identifier of the charge cable. An overload protection device is connected to and monitors the feed line. The overload protection device is an automatically switching overload protection device in which at least one identifier-specific trigger criterion is stored for each of at least two load capacity identifiers of the charging cable. The overload protection device is capable of automatically selecting the identifier-specific trigger criterion assigned to the load capacity identifier depending on the load capacity identifier of the charging cable, and of shutting off a switching device of the overload protection device arranged in the feed line depending on the selected trigger criterion.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: April 16, 2019
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventor: Remo Gellert
  • Patent number: 10222290
    Abstract: Systems and a method for detecting potential areas of corrosion under insulation are provided. An exemplary system includes an enclosure, insulation disposed upon an outer surface of the enclosure, and a number of microelectromechanical system (MEMS) sensors. The MEMS sensors detect water proximate to the insulation.
    Type: Grant
    Filed: June 15, 2016
    Date of Patent: March 5, 2019
    Assignee: ExxonMobil Upstream Research
    Inventors: William N. Yunker, Michael T. Matheidas
  • Patent number: 9093863
    Abstract: A smart circuit breaker for an AC power supply circuit that has a limited capacity for supplying power to one or more electrical loads. Smart circuit breaker includes a sensing circuit to dynamically determine the available load capacity of the AC power supply circuit. A reporting circuit reports the dynamically available load capacity to a controller, an existing electrical load, and/or a potential electrical load on the AC power supply circuit. The AC power supply circuit, the existing electrical load, and/or the potential electrical load can adjust operations based on the reported availability of load capacity.
    Type: Grant
    Filed: November 7, 2011
    Date of Patent: July 28, 2015
    Assignee: Elwha LLC
    Inventors: Roderick A. Hyde, Jordin T. Kare, Lowell L. Wood, Jr.
  • Patent number: 9082562
    Abstract: An inrush-current suppressing device includes: a residual-magnetic-flux calculating unit that calculates a residual magnetic flux in a reference phase of a three-phase transformer while assuming a maximum magnetic flux level generated at a time of applying a rated voltage as 1 PU based on a measurement result of a transformer-voltage measuring unit before and after opening a three-phase circuit breaker; a stationary-magnetic-flux calculating unit that calculates a stationary magnetic flux in the reference phase of the three-phase transformer with reference to the maximum magnetic flux level obtained as the 1 PU based on a measurement result of a power-supply-voltage measuring unit, in response to a closing command to the three-phase circuit breaker; and a control unit that actuates a switch of the three-phase circuit breaker corresponding to the reference phase at a timing when the stationary magnetic flux and the residual magnetic flux in the reference phase match each other.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: July 14, 2015
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Sadayuki Kinoshita, Kenji Kamei, Tomohito Mori
  • Patent number: 9063202
    Abstract: A controller (500) in an electric drive system is used to determine whether a phase current imbalance in the output winding of a power generator (204) exists. During operation, the controller (500) receives a set of power generator diagnostic values corresponding to the phase currents output by the power generator (204). Next, the controller (500) determines a set of expected operating phase current values. The controller (500) then compares the obtained diagnostic values to one or more corresponding expected operating values. If the difference is greater than a threshold, the controller (500) provides an appropriate fault indication indicative of a phase current imbalance.
    Type: Grant
    Filed: September 15, 2008
    Date of Patent: June 23, 2015
    Assignee: Caterpillar Inc.
    Inventors: Matthew Hendrickson, Benjamin P. Gottemoller
  • Patent number: 9036382
    Abstract: Methods and apparatus are presented for detecting phase loss and/or excessive ripple in a power converter, in which bandpass filters are used to obtain harmonic voltage amplitudes associated with the power converter DC bus, and phase loss is detected if a ratio of the second harmonic to the sixth harmonic and/or a ratio of the fourth harmonic to the sixth harmonic exceed predetermined threshold values.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: May 19, 2015
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Bing Li, David Leggate, Timothy Rowan
  • Publication number: 20140340800
    Abstract: A circuit breaker trip unit includes an input section receiving a phase current level signal. A processor is in communication with the input section and generates a first trip signal based on the phase current level signal and user-adjustable trip settings. The trip settings include long time and short time pickup and delay settings. An analog instantaneous trip circuit is in communication with both of the input section and the processor. The analog instantaneous trip circuit includes a digital potentiometer having a non-volatile memory. The potentiometer provides a reference signal corresponding to a resistance setting stored in the memory. The analog instantaneous trip circuit compares the phase current level and reference signals, and generates a second trip signal based on a result of the comparing. The processor programs the resistance setting stored in the memory according to a user-adjustable instantaneous current pickup setting.
    Type: Application
    Filed: August 5, 2014
    Publication date: November 20, 2014
    Inventor: Helmut Weiher
  • Patent number: 8823356
    Abstract: Processes, machines, and articles of manufacture that may serve to enable the detection or determination of alternating line voltages from an alternating power source, such as the power grid, are provided. This automatic sensing may be useful when connections are made to the power grid, such that when connections are made, the connections may be configured to be compatible with the available power source. This automatic sensing may also be useful if power sources change characteristics over time or if devices may be connected to different power sources over time.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: September 2, 2014
    Assignee: SolarBridge Technologies, Inc.
    Inventor: Patrick L. Chapman
  • Publication number: 20140233142
    Abstract: There are provided an apparatus and a method for detecting a voltage unbalance and a power meter using the same. The apparatus for detecting a voltage unbalance may a voltage unbalance detection unit including a plurality of voltage unbalance detectors that respectively receive a phase voltage from among a plurality of phase voltages included in input voltages and when the phase voltage is unbalanced, output interrupt signals, and a control unit determining a phase in which an interrupt has occurred, by using a plurality of pieces of accumulated voltage information regarding the plurality of phase voltages output from the plurality of respective voltage unbalance detectors.
    Type: Application
    Filed: May 10, 2013
    Publication date: August 21, 2014
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventor: Jung Hoo LEE
  • Publication number: 20140185171
    Abstract: A three-phase power control apparatus includes a first circuit breaker, a power supply controller, and a three-phase power monitor. When the three-phase power monitor detects an error in three phase voltages provided by a three-phase power supply, the three-phase power monitor transmits a voltage signal to the power supply controller. When the power supply controller receives the voltage signal from the three-phase power monitor, the power supply controller controls the first circuit breaker to disconnect a load from the three-phase power supply. A three-phase power control method is also provided.
    Type: Application
    Filed: October 22, 2013
    Publication date: July 3, 2014
    Applicants: HON HAI PRECISION INDUSTRY CO., LTD., HONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD.
    Inventor: WEN-KAO FENG
  • Publication number: 20140139959
    Abstract: According to one embodiment, an excitation inrush current suppression device for suppressing excitation inrush currents flowing through a breaker of the three-phase collective operation type for opening and closing connection is configured to measure a three-phase AC voltage of the power supply bus bar to calculate prospective magnetic fluxes of the transformer, and to measure a three-phase AC voltage on the transformer side to calculate residual magnetic fluxes of the transformer after shutoff, so as to set the breaker closed when polarities of the prospective magnetic fluxes respectively agree with polarities of the residual magnetic fluxes in all of the phases respectively.
    Type: Application
    Filed: January 24, 2014
    Publication date: May 22, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kei KAWASAKI, Tadashi KOSHIZUKA, Shiro MARUYAMA, Minoru SAITO, Noriyuki NAGAYAMA
  • Publication number: 20140104735
    Abstract: A protection relay is provided for protection of an electric network. The protection relay measures an electric signal in the network, converts the measured signal to a frequency domain representation of the measured signal, and generates a measuring phasor based on the frequency domain representation, where the phase rotation of the measuring phasor is dependent on one or more frequency components present in the measured electric signal. The protection relay compares the measuring phasor to the reference phasor, where the phase rotation of the reference phasor is based on either a nominal or a measured frequency of the electric network, and launches protection if the comparison of the of the measuring phasor and the reference phasor fulfils a predetermined criterion.
    Type: Application
    Filed: December 20, 2013
    Publication date: April 17, 2014
    Applicant: ABB Technology AG
    Inventors: Kari VANHALA, Petri Koivula
  • Patent number: 8659863
    Abstract: A circuit protection device and a protection method thereof are provided. The circuit protection device includes a pulse width modulation unit which detects in order for a plurality of current phase of a plurality of transistors. The pulse width modulation unit decides the current phase of the transistors override a first threshold value whether. Then, the pulse width modulation unit sends a control signal to close the transistor that the current phase exceeds the first threshold value, so as to avoid the transistor burn down.
    Type: Grant
    Filed: December 18, 2011
    Date of Patent: February 25, 2014
    Assignee: Giga-Byte Technology Co., Ltd.
    Inventors: Hou Yuan Lin, Chen Shun Chen, Tse Hsine Liao, Kuei Min Chen
  • Patent number: 8624578
    Abstract: A tool for configuring a branch current monitor facilitates mapping the connections of branch circuits to voltage sources in a power distribution panel.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: January 7, 2014
    Assignee: Veris Industries, LLC
    Inventors: Matthew Rupert, Marc Bowman, Michael Bitsch, Martin Cook
  • Patent number: 8526155
    Abstract: A phase-control switchgear includes a circuit breaker, a phase difference detection unit, a storage unit, and a circuit breaker control unit. The phase difference detection unit detects a phase difference between voltages of a specific phase (U-phase) of buses to which three-phase generators are respectively connected, at a plurality of time points. The storage unit stores the detected phase differences. When the three-phase generators are out of synchronization, the circuit breaker control unit estimates a breaking time point at which the phase difference between the voltages of the U-phase of the buses will be in the range of not less than ?80° and not more than 80°, based on the phase differences at the plurality of time points stored in the storage unit. The circuit breaker control unit opens the circuit breaker to break a current at the estimated breaking time point. This makes it possible to suppress a transient voltage generated between electrodes of the circuit breaker after the current is broken.
    Type: Grant
    Filed: December 25, 2008
    Date of Patent: September 3, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Sadayuki Kinoshita, Kenji Kamei, Tomohito Mori, Hiroki Ito
  • Publication number: 20130208382
    Abstract: A protection circuit for protecting a dimmer circuit controlling an inductive load including an imbalance detector for detecting an asymmetrical operation in the load and circuit control means for causing the dimmer circuit to reduce a DC component in the load upon detection of the asymmetrical operation. A load imbalance detector is also disclosed having a load DC component detector, a comparator and a signal generating means for generating a circuit shut down signal if the DC component exceeds a pre-set DC threshold.
    Type: Application
    Filed: December 26, 2012
    Publication date: August 15, 2013
    Applicant: CLIPSAL INTEGRATED SYSTEMS PTY LTD
    Inventor: Clipsal Integrated Systems Pty Ltd
  • Patent number: 8462476
    Abstract: A method and a differential protection apparatus for an electrical link in a medium, high or very high voltage power distribution network. This method, in which two differential protection devices are disposed at the two ends (A, B) of said link, includes a step during which a comparison is made between the current measured locally and the current measured remotely, after said devices have been resynchronized by phase shifting the data received from the end situated remotely by one half of the sum of the outward and return propagation times; and a second step during which, if an angular phase difference is found to exist between two currents after resynchronization, automatic compensation is effected by servocontrolling the angle of the current vectors.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: June 11, 2013
    Assignee: Areva T&D Protection & Controle
    Inventor: Jean Marmonier
  • Publication number: 20130141827
    Abstract: A method of determining a fault parameter of a fault on an AC transmission line 10 of a power distribution system 1 relative to a measurement location 12 of the transmission line 10 comprising: measuring a time-dependent current of the transmission line 10 at the measurement location 12; transmitting a current signal indicative of the measured current to a decision logic section 36, the current signal comprising a plurality of pre-fault current values and a plurality of post-fault current values; determining, by the decision logic section 36, a plurality of phase difference values indicative of respective phase differences between respective pre-fault current values and respective post-fault current values; accumulating the plurality of phase difference values into an accumulated phase difference parameter; obtaining the fault parameter by comparing the accumulated phase difference parameter to a threshold value; and outputting the determined fault parameter.
    Type: Application
    Filed: January 28, 2013
    Publication date: June 6, 2013
    Applicant: ABB RESEARCH LTD
    Inventor: ABB RESEARCH LTD
  • Patent number: 8433528
    Abstract: A ground fault detection system is provided. The ground fault detection system includes a magnetic core having first and second primary legs and a secondary leg disposed between the first and second primary legs. The ground fault detection system also includes first and second primary windings disposed around the first and second primary legs respectively and configured to introduce current in the first and second primary legs. Further, the ground fault detection system includes first and second secondary windings disposed around the first and second primary legs respectively and configured to detect a ground fault based upon a magnetic flux generated in response to the introduced current.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: April 30, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Craig R. Winterhalter, Lixiang Wei, Zoran V. Vrankovic
  • Patent number: 8369055
    Abstract: A method of determining out of step condition and an instance of separation within electrical power system. The method does not require user settings and ensures reliable discrimination between recoverable power swing and pole slips that indicates non-recoverable power swing and the need for system separation. The method also allows tripping at a user selected system angle if desired. A calculated angle is used to determine the magnitude of the swing current to control the tripping at the desired angle ? when the system could be safely split after detection of out of step condition based on the criteria of this invention.
    Type: Grant
    Filed: December 13, 2007
    Date of Patent: February 5, 2013
    Assignee: Areva T&D UK Ltd
    Inventors: Branislav Cvorovic, Harmeet Kang
  • Publication number: 20130027826
    Abstract: A circuit protection device and a protection method thereof are provided. The circuit protection device includes a pulse width modulation unit which detects in order for a plurality of current phase of a plurality of transistors. The pulse width modulation unit decides the current phase of the transistors override a first threshold value whether. Then, the pulse width modulation unit sends a control signal to close the transistor that the current phase exceeds the first threshold value, so as to avoid the transistor burn down.
    Type: Application
    Filed: December 18, 2011
    Publication date: January 31, 2013
    Inventors: Hou Yuan Lin, Chen Shun Chen, Tse Hsine Liao, Kuei Min Chen
  • Publication number: 20120120534
    Abstract: A method includes receiving N power signals, each having a different one of N phases, over N power supply lines, where N is an integer greater than two. The method further includes selectively activating a first switch to allow a first current to flow from a first one of the N power supply lines to a second one of the N power supply lines. The method includes generating a signal based on the first current, and selectively generating a phase failure signal when the signal is less than a predetermined threshold.
    Type: Application
    Filed: January 30, 2012
    Publication date: May 17, 2012
    Applicant: Emerson Climate Technologies, Inc.
    Inventors: Yunfeng Wu, Yongbing Wang
  • Patent number: 8155902
    Abstract: A sensor-less technique is described for detecting the status of an AC contactor of a power inverter. In one embodiment, a method is provided of sensing an unexpected condition of an AC contactor used to couple to a power distribution system a power inverter having at least one power conductor. The method includes determining a voltage value for the conductor; determining a current value for the conductor; determining a phase difference using the voltage value and the current value; and monitoring successive values of the phase difference to produce a monitoring result. Depending on the monitoring result, a determination is made whether or not to issue an alert signal. Control routines embodying such technique may be stored on computer-readable media. A power inverter using such technique is described.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: April 10, 2012
    Assignee: Xantrex Technology Inc.
    Inventors: Jun Yin, Renjie Xu
  • Patent number: 8138622
    Abstract: Borehole instruments are powered by AC instrument power transmitted on all three phases of a power cable concurrently carrying three phase motor power, the instrument power transmitted at a multiple of the motor power frequency and having a corresponding fraction of the motor power voltage, and received via a capacitive coupling sufficient to withstand high-voltage cable insulation testing. The phase-to-neutral motor power provides approximately the same power level to the borehole instruments if a phase shorts to ground.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: March 20, 2012
    Assignee: Baker Hughes Incorporated
    Inventors: James E. Layton, Dick L. Knox, Gordon L. Besser
  • Patent number: 7808128
    Abstract: Network protectors isolate the secondary side of a transformer from a load distribution network. It is useful to have information about the electrical parameters for the transformer and the load side of an open network protector and it is useful to have access to electrical parameters for a closed network protector. Information about a network protector can be provided to a transmitter used to convey information about the transformer associated with that network protector so that information about the network protector can be sent over power liner carrier to a centralized receiver.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: October 5, 2010
    Assignee: DGI Creations, LLC
    Inventors: John Robert Weber, Jr., Carl Francis Scheuermann
  • Patent number: 7791352
    Abstract: A method for detecting a fault in semiconductor components in electrical machines, e.g., three-phase generators, used in the automotive field is described. The electrical machine is equipped with multiple windings, each having a phase terminal U, V, W. The electrical machine is checked by determining the voltage in one of its phase terminals U, V, W both during operation and at rest. The phase terminals of phase terminals U, V, W of the electrical machine that are not taken into account are checked for voltage dips with respect to a potential or are checked for the output currents.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: September 7, 2010
    Assignee: Robert Bosch GMBH
    Inventor: Guenter Nasswetter
  • Patent number: 7589438
    Abstract: A method and apparatus for transferring AC electrical power to a load from a first power source to a second power source provides for a time delay in the transfer to avoid problems associated with differences in the phases between the power sources. The phase of the voltage waveform from each power source is sensed continuously, and the phase difference is known at all times, so that it can be used when the transfer is necessary. The method and apparatus monitors the voltage from the first power source, and initiates the transfer from the first power source to the second power source in response to an unacceptable condition from the first power source. The second power source is connected only after waiting for a period of time corresponding to the appropriate time delay.
    Type: Grant
    Filed: July 7, 2005
    Date of Patent: September 15, 2009
    Assignee: LayerZero Power Systems, Inc.
    Inventor: James M. Galm
  • Publication number: 20090128972
    Abstract: An apparatus includes a first optocoupler and a control module. The first optocoupler selectively allows a first current to flow from a first one of a first pair of N power supply lines to a second one of the first pair. N is an integer greater than two. The N power supply lines each provide a phase signal. The control module controls the first optocoupler and determines an occurrence of a phase failure of the phase signals based on a first signal, which is based on the first current.
    Type: Application
    Filed: November 13, 2008
    Publication date: May 21, 2009
    Applicant: Emerson Climate Technologies, Inc.
    Inventors: Yunfeng Wu, Yongbing Wang
  • Publication number: 20090097173
    Abstract: A control unit of an electric power supply system causes, responsive to a closing command signal, a switch corresponding to R phase to be thrown at a timing when a stationary magnetic flux and a residual magnetic flux of R phase are coincident with each other and then subsequently causes other switches corresponding to S phase and T phase to be thrown at a timing which is delayed from a zero point of an alternating voltage of R phase by a predetermined phase angle of 0-30 degrees, such that the difference of the stationary magnetic flux and the residual magnetic flux of each of S phase and T phase is minimum. Therefore, an exciting incoming current which flows into a three-phase transformer at a time of throwing a three-phase breaker provided with interpole capacitors can be suppressed.
    Type: Application
    Filed: March 19, 2008
    Publication date: April 16, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Sadayuki KINOSHITA, Kenji Kamei, Tomohito Mori, Hiroki Ito
  • Patent number: 7480124
    Abstract: Systems and methods that detect a phase loss condition in a three-phase electrical power source are presented. The system includes a detection component that measures and/or monitors a magnitude and frequency of a voltage of a power source, and a controller component that compares measured and/or monitored voltage characteristics to characteristics associated with phase loss.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: January 20, 2009
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Jeffery J. Pankau, Robert Harris Schmidt
  • Patent number: 7453674
    Abstract: A method for protecting an electrical generator which includes providing an electrical generator which is normally synchronously operated with an electrical power grid; providing a synchronizing signal from the electrical generator; establishing a reference signal; and electrically isolating the electrical generator from the electrical power grid if the synchronizing signal is not in phase with the reference signal.
    Type: Grant
    Filed: March 20, 2007
    Date of Patent: November 18, 2008
    Assignee: Battelle Energy Alliance, LLC
    Inventors: Barry W. Kuehnle, Jeffrey B. Roberts, Ralph W. Folkers
  • Patent number: 7403015
    Abstract: A system for monitoring a circuit breaker that includes a monitoring device in electronic communication with the circuit breaker and a receiving device located separately from the monitoring device. The monitoring device receives data from the circuit breaker and wirelessly transmits at least a portion of the data such as one or more phase currents measured from a network which the circuit breaker protects, an ambient temperature within the circuit breaker, and/or data relating to a trip condition of the circuit breaker. The receiving device receives the transmitted data and displays all or a portion thereof. The monitoring device also includes a display that displays all or a portion of the data.
    Type: Grant
    Filed: February 9, 2005
    Date of Patent: July 22, 2008
    Assignee: Eaton Corporation
    Inventors: Harry J. Carlino, Todd M. Shaak
  • Patent number: 7355866
    Abstract: The disclosure relates to a method of detecting the phase-loss state of the three-phase power supply. When the phase-loss condition occurs in the input three-phase power supply of the power converter, it is determined whether the three-phase power source is in the phase-loss state through the characteristic of the frequency and amplitude variations of the ripple voltage of the DC bus, and through the sampling and the continuous detecting of the ripple voltage variations by making use of the sensor of the power converter in cooperation with the software calculation, it is determined whether the three-phase power source is in a phase-loss state. When the detected ripple voltage of the DC bus fulfills the phase-loss conditions, it is determined that the three-phase power source is in a phase-loss state.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: April 8, 2008
    Assignee: Delta Electronics Inc.
    Inventors: Ting-Chung Hsieh, Shih-Chieh Liao
  • Patent number: 7352549
    Abstract: The subject matter of the present invention is a method of automatically recognizing an electrical system by which both the voltage of an electrical system (2) and the phase angle between phases of the system are monitored so that human technical failure upon connecting a plant (1) to said electrical system (2) be reliably prevented.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: April 1, 2008
    Assignee: SMA Technologie AG
    Inventors: Frank Greizer, Sven Bremicker
  • Patent number: 7319576
    Abstract: Provided is an apparatus and method for providing differential protection for a phase angle regulating transformer having a load side and a source side in a three-phase power system. The method includes calculating a first positive sequence component and a first negative sequence component associated with incoming secondary currents detected on the source side, calculating a second positive sequence component and a second negative sequence component associated with outgoing secondary currents detected on the load side, applying a phase angle shift to the second positive sequence component and the second negative sequence component to form a compensated positive sequence component and a compensated negative sequence component, respectively, and determining an operate current value and a restraint current value for each of a positive and negative sequence differential element of the differential protection based on the compensated positive sequence component and the compensated negative sequence component.
    Type: Grant
    Filed: August 18, 2005
    Date of Patent: January 15, 2008
    Assignee: Schweitzer Engineering Labortories, Inc.
    Inventor: Michael J. Thompson
  • Patent number: 7299143
    Abstract: The present invention is directed to a method and apparatus for improving operational reliability during a loss of a phase voltage (LOV) in a multi-phase power system, wherein a voltage representative of the LOV phase is calculated. The representative voltage is used for computing a reference polarizing voltage suitable for a protection unit.
    Type: Grant
    Filed: May 12, 2006
    Date of Patent: November 20, 2007
    Assignee: ABB Technology AG
    Inventor: Elmo Price
  • Patent number: 7259947
    Abstract: Respective contact terminals in respective arc-suppressing spaces of respective breakers are opened at a voltage zero point of any phase of three phases, simultaneously among the three phases. If current breaking is carried out for the three phases at the same time, when the breakers of the three phases are opened, the residual magnetic levels of the respective phases of a transformer can be controlled so that the residual magnetic flux level of the phase opened at the voltage zero point is maximum (for example, ?2K or +2K) and the residual magnetic flux level of the other two phases are opposite in polarity to the residual magnetic flux level of the phase concerned and equal to substantially the same residual magnetic flux (for example, +K and +K or ?K and ?K) which is equal to about one half of the residual magnetic flux level of the phase concerned.
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: August 21, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Sadayuki Kinoshita, Hiroki Ito, Haruhiko Kohyama, Kenji Kamei
  • Patent number: 7242563
    Abstract: In one embodiment of the invention, a reverse phase control power switching circuit for controlling the flow of current through a load from an AC source comprises a sensing bridge in series with the load and the AC source. The conductive state of the sensing bridge is responsive to a pulse generator and a zero crossing detection and overload protection means. Phase control means coupled to the pulse generator determines turn off of the sensing bridge is reset by the zero crossing detection and overload protection means. Responsive to a load current condition exceeding a maximum current caused by an overload or a short, the zero crossing detection and overloading protection network terminates conduction of current through the sensing bridge. The sensing bridge starts conducting current to the load at the beginning of the AC cycle and continues to conduct to a desired AC voltage phase angle or earlier if an excessive current condition caused by an overload condition or a short occurs.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: July 10, 2007
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Jenkin P. Hua, Alfred J. Lombardi
  • Patent number: 7218015
    Abstract: To the end of providing a constant AC voltage to a variable load (1) which is arranged remote of a voltage source (3), a voltage drop over an electrical supply line (2) which connects the load to the voltage source (3) is compensated for by a compensation AC voltage which, if added to the constant AC voltage, results into the output AC voltage Ufull of the voltage source (3) and the value of which is varied depending on the absolute value of the alternating current (I) conducted to the load (1) and on the phase angle phi between the output AC voltage Ufull of the voltage source (3) and the alternating current (I).
    Type: Grant
    Filed: July 11, 2003
    Date of Patent: May 15, 2007
    Assignee: RWE Piller GmbH
    Inventors: Reinhard Engelhardt, Stephan Leschke
  • Patent number: 7126801
    Abstract: A polarity protection circuit contains a metal oxide semiconductor field effect transistor (FET) that pets its control voltage via an electrical connection from supply voltage lines and a transistor that pets its control voltage via another connection from the supply voltage lines. When a supply voltage has a wrong polarity the FET is in a non-conducting state. If in the supply voltage lines during normal operation there occurs a short circuit that tends to chance a direction of the current, the transistor rapidly discharges a gate charge of the FET, and the current flow in the wrong direction is prevented.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: October 24, 2006
    Assignee: Tellabs Oy
    Inventor: Sami Jokinen
  • Patent number: 7095138
    Abstract: A controller is disclosed for determining that the currents from the two AC power sources are correctly phased. Required circuitry can be disposed within a housing from which extend power cables having single phase 240V AC, 50 A male connector plugs connected at remote ends. Prongs in each of plugs can be arranged so that the plugs are connectable to a 240V, single phase AC source. A power cable, having a connector at a remote end, can also extend from the housing. The power cable connector can be connected to an AC power supply. The power cable connector supply a power transformer with single phase AC power at 240V and 100 A. The circuitry can assure that the phases and voltages of the two AC sources driving the connectors are properly connected to the connectors to enable the cable to supply the power cable connector with single phase AC.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: August 22, 2006
    Inventor: Jacques Brunier
  • Patent number: 7095598
    Abstract: There is provided an apparatus for producing a trip signal to activate a circuit breaker in an alternating current power line, said apparatus comprising: a sensing circuit operable to sense values representing: a phase difference between current and voltage in said power line; and current amplitude in said power line; a comparison circuit operable to compare said sensed values of phase difference and current amplitude with a trip characteristic defining fault conditions and non-fault conditions and to generate a fault indication signal when a fault condition arises; a fault discriminator operable in response to said fault indication signal to generate a fault-identifying signal discriminating between: a first class of fault in which a mean current value after said fault indication increases relative to a mean current value before said fault indication; and a second class of fault in which a mean current value after said fault indication does not increase relative to a mean current value before said fault indi
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: August 22, 2006
    Assignee: FRDX Limited
    Inventors: Gordon Bryon Scott, Rodney A. Stone
  • Patent number: 6896551
    Abstract: A power line phase coupler system for repeating data signals between power line phases that can be easily installed by a user. The power line phase coupler system includes a housing, a female connector positioned within the housing, a male connector electrically connected to the female connector by a length of cord, and a repeater coupler electrically connected to the male connector. The repeater coupler is electrically connected between Phase A and Phase B of the male connector for repeating and amplifying a data signal received from either phase to the opposite phase.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: May 24, 2005
    Assignee: Echelon Corporation
    Inventors: Douglas L. Hauck, David L. Kvidt, Jeff L. Johnson
  • Patent number: 6841761
    Abstract: U.S. Ser. No. 2002009312A cooking appliance having an electric resistance heater is connected to a multiple phase external power source and includes a system for compensating for whether the cooktop is connected to 240V split phase system wherein the two phases are 180° out of phase with each other or a 208V three phase system which has two phases that are only 120° out of phase. In particular, the cooktop includes a system for distinguishing whether the multiple phases of the external power source are 180° out of phase such that the electric resistance heater is compensated against whether it is connected to a three phase external power supply.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: January 11, 2005
    Assignee: Whirlpool Corporation
    Inventors: Massimo Banzato, Anthony E. Jenkins
  • Publication number: 20040233599
    Abstract: The present invention is directed to a comparator circuit for use with in-phase and quadrature phase signals and a method of comparing a resultant vector of the in-phase and quadrature phase signals. In one embodiment, the comparator circuit includes a non-titled comparison circuit that compares a resultant vector of the in-phase and quadrature phase signals to vertical and horizontal comparison boundary member pairs. The comparator circuit also includes a tilted comparison circuit, coupled to the non-tilted comparison circuit, that compares the resultant vector to comparison boundary member diagonals coupled to the vertical and horizontal comparison boundary member pairs. The comparator circuit may still further include a combiner circuit that provides a comparison signal based on signals from the non-tilted and tilted comparison circuits.
    Type: Application
    Filed: May 21, 2003
    Publication date: November 25, 2004
    Applicant: Agere Systems Inc.
    Inventor: Erik B. Busking
  • Publication number: 20040212940
    Abstract: A solid state relay coupleable to first and second phase busses of an AC power source for switching power from the first and second phase busses to a load comprises: first and second power semiconductor switches connected in a series circuit configuration and coupleable to the first and second phase busses for switching power from the first and second phase busses to the load, each of the first and second power semiconductor switches controllably operative in conductive and non-conductive states; first and second power diodes coupled respectively across the first and second power semiconductor switches; and a control circuit for monitoring a polarity relationship of the first and second phase busses and controlling the first and second switches between conductive and non-conductive states based on the monitored polarity relationship. A method of operating the solid state relay is further disclosed.
    Type: Application
    Filed: March 18, 2004
    Publication date: October 28, 2004
    Inventors: Michael M. Kugelman, Steven C. Simshauser
  • Publication number: 20040057178
    Abstract: A directional ground relay (50) for receiving electric values relating to voltage and current from a power transmission line (1) to be protected. The directional ground relay may decide a direction of a fault in the power transmission line based upon the electric values. The directional ground relay comprises a zero-phase sequential current calculation unit (10-2) for calculating a zero-phase sequential current based upon the current detected from the power transmission line. The directional ground relay further comprises a phase-comparison unit (10-3) configured to compare a phase of the zero-phase sequential current to a phase of voltage corresponding to the voltage in the power transmission line, to decide whether the zero-phase sequential current is within a pre-determined range, and to output the phase of the voltage as a faulty phase of voltage, when the zero-phase sequential current is within the pre-determined range.
    Type: Application
    Filed: July 21, 2003
    Publication date: March 25, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takahiro Kase, Yasutaka Sonobe, Hidenari Amo
  • Patent number: 6661630
    Abstract: A distance relay for protection of a transmission line, which is capable of estimating apparent impedances with respect to faults on the transmission line involving fault resistances, more particularly faults at local and remote ends of a protection zone of the transmission line, and compensating for the magnitudes and phases of the estimated apparent impedances, so as, to minimize a reactance effect resulting in a mal-operation or non-operation or the distance relay. If a fault occurs on the transmission line, the distance relay determines whether the amount of zero-sequence current resulting from overcurrent exceeds a predetermined threshold value, so as to determine whether the occurred fault is an earth fault or a short fault.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: December 9, 2003
    Assignees: Youho Electric Co. Ltd.
    Inventor: Yong Jin Ahn