In A Polyphase System Patents (Class 361/47)
  • Patent number: 10416221
    Abstract: The present invention provides a method for current for fault identification in a transmission line and an apparatus thereof. The method comprises the following steps: measuring the real-time values of the currents and the voltages of the other unbroken healthy phase conductors when a single-phase fault occurs; calculating the inductive voltage and the capacitive coupling voltage according to the measured currents and voltages respectively; comparing the capacitive coupling voltage with the inductive voltage multiplied by a factor, in which the multiplication result is used as a self-adjusted threshold based on the real time load condition of the transmission line; and identifying the fault type based on the maximum of the capacitive coupling voltage and the multiplication.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: September 17, 2019
    Assignee: ABB Schweiz AG
    Inventors: Ying Yang, Youyi Li, G. Pradeep
  • Patent number: 10283955
    Abstract: This disclosure provides systems, methods, and apparatuses for current monitoring. For example, in a system that includes a first circuit breaker coupled to a primary power source and a second circuit breaker coupled to an alternative power source, there is provided an apparatus that includes a controller circuit configured to prevent back-feeding of power from the alternative power source to the primary power source via tripping the second circuit breaker, in response to the total current in the first and second circuit breakers exceeding a defined maximum level.
    Type: Grant
    Filed: December 30, 2015
    Date of Patent: May 7, 2019
    Assignee: QFE 002 LLC
    Inventor: Paul Martin Cruz
  • Patent number: 10243346
    Abstract: An apparatus for mitigating GIC (geomagnetically induced current) effects through a fuzzy logic controlled variable resistor. Under GIC conditions (or any unbalanced fault current condition), the GIC or unbalanced fault current flows through the neutral of a power transformer. It is detected by the fuzzy logic controller, which sends a signal to a switch to open. The resistor is in the circuit and impedes the flow of current through the neutral, thereby protecting the transformer from getting overheated.
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: March 26, 2019
    Inventor: Mohd Hasan Ali
  • Patent number: 9729074
    Abstract: A multifunctional signal isolation converter (10) is arranged in a safe area (20), and is applied to an electronic apparatus (40) arranged in a dangerous area (30). The multifunctional signal isolation converter (10) includes a microprocessor (108) and a power supply unit (116). The microprocessor (108) determines whether internal functions of the multifunctional signal isolation converter (10) are normal or not to obtain a first judgment value. The electronic apparatus (40) sends an input signal (42) to the microprocessor (108). The microprocessor (108) determines whether functions of the electronic apparatus (40) are normal or not to obtain a second judgment value according to the input signal (42). The microprocessor (108) controls whether the power supply unit (116) supplies a driving power (122) to the electronic apparatus (40) or not according to the first judgment value and the second judgment value.
    Type: Grant
    Filed: December 12, 2014
    Date of Patent: August 8, 2017
    Assignee: FINETEK CO., LTD.
    Inventors: Liang-Chi Chang, Jen-Shun Wang, Chi-Fan Liao, Yi-Liang Hou
  • Patent number: 9575101
    Abstract: The present disclosure is a system for monitoring power that has a unified polyphase distribution transformer monitoring (PDTM) device that interfaces with at least three electrical conductors electrically connected to a transformer. In addition, the PDTM device measures a current and a voltage of each of the three electrical conductors. Additionally, the system has logic that calculates values indicative of power corresponding to the transformer based upon the currents and the voltages measured and transmit data indicative of the calculated values.
    Type: Grant
    Filed: March 18, 2014
    Date of Patent: February 21, 2017
    Assignee: GRID20/20, Inc.
    Inventors: Lan Xu, Eric George de Buda
  • Patent number: 9470735
    Abstract: A noise signal for a malfunction test is inputted to a ground terminal, and a frequency property of the magnitude of the power at which a designated electric circuit causes a malfunction is found. A detection reference ground of a detection part for detecting malfunctions of the designated electric circuit is connected at high impedance to a ground of the targeted circuit. Differential input parts are provided to the detection part, a to-be-detected part of the designated electric circuit is connected to one differential input part, and the ground of the targeted circuit is connected to the other differential input part. A ground of a noise source is isolated from a ground of a power source circuit for supplying a power source to the designated electric circuit. The ground of the noise source is galvanically isolated from the ground of the designated electric circuit.
    Type: Grant
    Filed: June 11, 2014
    Date of Patent: October 18, 2016
    Assignee: ROHM CO., LTD.
    Inventor: Noriaki Hiraga
  • Patent number: 9431941
    Abstract: Methods for detecting a short fault of an alternator rectifier electronic component include sampling a field winding voltage or current signal of an alternator, during operation of the alternator, and determining a fault ripple period at which the alternator field winding signal exceeds a fault threshold. A short fault of an electronic component of a rectifier coupled to the alternator is detected in the event that the fault ripple period closely matches an alternator armature period. Alternatively or additionally, the sampled field winding signal is band pass filtered, and a short fault is detected in the event that an amplitude of the band pass filtered field winding signal exceeds a fault threshold. The methods can be implemented, for example, by an apparatus that includes a hysteresis frequency counter, a frequency comparator, and a countdown timer.
    Type: Grant
    Filed: February 12, 2015
    Date of Patent: August 30, 2016
    Assignee: General Electric Company
    Inventors: Rajeev Verma, Bret Dwayne Worden
  • Patent number: 9404958
    Abstract: A first X capacitor is connected between one of a plurality of hot line sections of a hot line that is located at an output side of a first relay as viewed from a commercial alternating-current power supply, and one of a plurality of neutral line sections of a neutral line that is located at an input side of a second relay as viewed from the commercial alternating-current power supply. A second X capacitor is connected between one of the hot line sections that is located at the output side of the first relay as viewed from the commercial alternating-current power supply, and one of the neutral line sections that is located at an output side of the second relay as viewed from the commercial alternating-current power supply.
    Type: Grant
    Filed: February 13, 2013
    Date of Patent: August 2, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Tetsuya Nozaki
  • Patent number: 9236726
    Abstract: The present invention includes a method for providing ground fault protection to a generator. The method includes determining the existing state of the generator and second, determining the updated alarm or trip conditions of a relay connected to the generator in view of the existing state of the generator. This includes estimating a ratio of the magnitude of the 3rd harmonic neutral voltage to the magnitude of the 3rd harmonic terminal voltage of a generator, along with calculating the residual 3rd harmonic voltage from the estimated 3rd harmonic ratio. From this, a comparison is made between the energy of the residual voltage with a fractional energy of the 3rd harmonic neutral voltage. Based on this comparison, an alarm or trip condition is signaled when the energy of the residual voltage is greater than the fractional energy of the 3rd harmonic neutral voltage.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: January 12, 2016
    Assignee: Alliant Energy Corporate Services, Inc.
    Inventor: Nader Safari-Shad
  • Patent number: 9063178
    Abstract: A system for measuring current includes a current monitoring system comprises a current sensor configured to sense a first current passing through a conductor and a voltage conversion device coupled to the current sensor and configured to receive a second current from the current sensor and convert the second current into a first voltage. A first scaling circuit is coupled to the voltage conversion device and configured to convert the first voltage to a second voltage proportional to the first current based on a first scaling factor, and a second scaling is circuit coupled to the voltage conversion device and configured to convert the first voltage to a third voltage proportional to the first current based on a second scaling factor, wherein the second scaling factor is different from the first scaling factor.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: June 23, 2015
    Assignee: Eaton Corporation
    Inventors: James H. Woelfel, Kaijam M. Woodley
  • Patent number: 9046560
    Abstract: A system and method for detecting high resistance ground faults in a power distribution system is disclosed. A fault detection and protection system is provided that includes a plurality of current sensors to measure current on the three phase output of the converter-inverter arrangement of the power distribution system and a controller configured to measure the three phase current on the three phase output, extract a fundamental current component for each phase of the three phase output, extract a third harmonic component for each phase of the three phase output, compare the fundamental current component and the third harmonic component extracted from each phase to a first threshold and a second threshold, respectively, and detect a ground fault on a phase of the three phase output based on the comparisons of the fundamental current component and the third harmonic component to the first and second thresholds.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: June 2, 2015
    Assignee: Eaton Corporation
    Inventor: Huaqiang Li
  • Publication number: 20150124358
    Abstract: A feeder power source for a network power system includes a network transformer having a delta three-phase primary winding and a three-phase secondary winding; a three-phase primary feeder electrically connected to the delta three-phase primary winding; a three-phase secondary bus electrically connected to the three-phase secondary winding; and a three-phase electrical switching apparatus structured to open and close the three-phase primary feeder. A network protector includes a network relay and a three-phase circuit breaker structured to open and close the three-phase secondary bus. A first circuit is electrically connected between at least one phase of the three-phase primary feeder and ground, and is structured to unbalance shunt impedance to the three-phase primary feeder ground. A second circuit detects a shift in system neutral and detects that the three-phase primary feeder is opened by the three-phase electrical switching apparatus.
    Type: Application
    Filed: November 1, 2013
    Publication date: May 7, 2015
    Applicant: EATON CORPORATION
    Inventor: ROBERT EUGENE HULSE
  • Patent number: 9001477
    Abstract: An open neutral protection method and apparatus including a blocking diode arrangement to prevent connection of power in circuits when the power source has an open neutral. In particular, when more than one branch circuits are connected to a power supply with more than one hot power lines, blocking diodes prevent back feed currents from activating relays connecting the power source to the branch circuits when the power source has an open neutral.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: April 7, 2015
    Assignee: Ericson Manufacturing Co.
    Inventor: Ronald W. Hughes
  • Patent number: 8988837
    Abstract: A power distribution system includes multiple uniform power distribution modules and multiple uniform mating connectors. A portion of the mating connectors are connected to the power distribution modules directly and the remainder are connected to the power distribution modules via a ground fault interrupt adapter.
    Type: Grant
    Filed: June 8, 2012
    Date of Patent: March 24, 2015
    Assignee: Hamilton Sundstrand Corporation
    Inventors: Carl A. Wagner, Kyle Stephen Ives, Jeffrey T. Wavering
  • Patent number: 8963476
    Abstract: A separately excited synchronous machine (1b1k) with an excitation circuit on the side of the rotor includes an excitation winding (3) and a power supply for the excitation winding (3) as well as a switching element (8a, 8e) for connecting the power supply to the excitation winding (3). Further, the synchronous machine (1b1k) comprises a first stator-side primary winding (5a5f) and a first rotor-side secondary winding (6a6f). Moreover, the synchronous machine (1b1k) may comprise a) a tap of the first rotor-side secondary winding (6d) connected to a control element (9a, 9e) of the switching element (8a, 8e) or b) a second rotor-side secondary winding (14d), which is coupled to the first stator-side primary winding (5a5f) and connected to a control element (9a, 9e) of the switching element (8a, 8e).
    Type: Grant
    Filed: March 2, 2012
    Date of Patent: February 24, 2015
    Assignee: BRUSA Elektronik AG
    Inventor: Enzo Illiano
  • Publication number: 20140285930
    Abstract: Methods may be provided to control an electro-permanent magnetic device powered from an AC mains power source provided through first and second power lines of a controller, wherein a first switch is provided on the first power line between the AC mains power source and the electro-permanent magnetic device and a second switch is provided on the second power line between the AC main power source and the electro-permanent magnetic device. In particular, a sequence of switching pulses may be transmitted through the first and second switches to change a magnetic state of the electro-permanent magnetic device. Related controllers are also discussed.
    Type: Application
    Filed: March 24, 2014
    Publication date: September 25, 2014
    Applicant: WEN TECHNOLOGY, INC.
    Inventor: John W. Powell
  • Publication number: 20140168830
    Abstract: A three-phase GFCI device is disclosed. The three-phase GFCI device may include contactors, a contactor control module configured to cause the contactors to close during normal operation of the GFCI device and open based on receiving a fault signal, a current detection module, a transient suppression module, a miswire detection module, a ground-fault test module, a ground load detection module, and a fail-safe module. In some examples, the GFCI device may include the stated modules in accordance with the UL 943C standard.
    Type: Application
    Filed: December 19, 2013
    Publication date: June 19, 2014
    Applicant: LITTELFUSE, INC.
    Inventors: MICHAEL P. VANGOOL, NEHAD EL-SHERIF EL-KHARBAWE, GEORGE J. FENTY
  • Patent number: 8749929
    Abstract: A circuit interrupter includes a trip actuator configured to cooperate with an operating mechanism to trip open separable contacts. The circuit interrupter also includes a ground fault sensor configured to sense a difference between a current through a first electrical conductor and a current through a second electrical conductor and to output an output current based on the sensed difference and a ground fault amplifier circuit configured to convert the output current to an output voltage. The circuit interrupter also includes first and second switches configured to electrically connect the output of the ground fault sensor to the ground fault amplifier circuit and the trip actuator, respectively. The circuit interrupter also includes a processor configured to control operation of the first and second switches and, when the first switch is closed, to control operation of the trip actuator based on the output voltage.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: June 10, 2014
    Assignee: Eaton Corporation
    Inventor: Theodore Miller
  • Publication number: 20140153145
    Abstract: An open neutral protection method and apparatus including a blocking diode arrangement to prevent connection of power in circuits when the power source has an open neutral. In particular, when more than one branch circuits are connected to a power supply with more than one hot power lines, blocking diodes prevent back feed currents from activating relays connecting the power source to the branch circuits when the power source has an open neutral.
    Type: Application
    Filed: December 4, 2012
    Publication date: June 5, 2014
    Inventor: Ronald W. Hughes
  • Patent number: 8736297
    Abstract: A fault signal indicates a single-pole or a double-pole fault in a three-phase electrical power grid which occurred during a present electric oscillation in the electrical power grid. The method assures that single-pole or double-pole faults occurring during oscillation can be detected with high reliability in that a symmetry signal is produced during the oscillation, which indicates whether the oscillation is symmetrical or unsymmetrical, and the phases of the electrical power grid are checked for an existing fault, wherein the symmetry signal is used for carrying out the check. The fault signal is produced if a fault was detected during the check. A protective device has an accordingly equipped control unit.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: May 27, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventor: Yilmaz Yelgin
  • Patent number: 8717718
    Abstract: Electrical load controls are provided which include an electrical switch assembly and a fault protection device within a common housing. The switch assembly includes an actuator, and is responsive to actuation of the actuator to switch ON or OFF electricity to the load. The protection device automatically responds to a fault condition by overriding the switch assembly by automatically blocking electrical connection between phase input and output terminals and neutral input and output terminals of the load control. The actuator includes a single external interface element. In one embodiment, actuation of the actuator switches ON or OFF electricity via control of the fault protection device, and in another embodiment, movement of the interface away from the housing exposes within the housing an internal user interface for the fault protection device.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: May 6, 2014
    Assignee: Leviton Manufacturing Company, Inc.
    Inventors: Michael Kamor, Adam Kevelos
  • Patent number: 8717719
    Abstract: The invention relates an inverter that may be set up as part of a power generation system for the connection of a number of substrings, which, using DC switches, can be connected to each other in series into a string and with the inverter. The inverter includes a bridge circuit to transform the power generated by the string comprising series-connected substrings into a grid-compatible AC voltage and to feed the power into a grid. The inverter also includes a ground fault detector arranged on the AC side of the bridge circuit for ground fault monitoring of the string. A controller connected to the ground fault detector controls the DC switches so that in case of a ground fault, a complete decoupling of the connection of the string from the bridge circuit and a separation of the string into potential-free substrings is performed. A method of operating such a power generation system is also described.
    Type: Grant
    Filed: May 11, 2011
    Date of Patent: May 6, 2014
    Assignee: SMA Solar Technology AG
    Inventors: Matthias Victor, Frank Greizer
  • Publication number: 20140071565
    Abstract: A first protective device monitors a first section of a power supply network for a symmetrical short-circuit and a second protective device monitors a second section for a symmetrical short-circuit. The second protective device is a reserve protective device, which emits a shut-off command to a power switch after a time lag when a symmetrical short-circuit in the first section is recognized. An oscillation recognition unit emits an oscillating signal which blocks the shutoff command if an oscillation in the power supply network has been recognized. External symmetrical short-circuits can be disconnected independently of an occurring oscillation, when the second protective device has recognized a symmetrical short-circuit in the first section, before the oscillation recognition unit recognizes an oscillation in the power supply network, the shut-off command is emitted independently of the presence of an oscillating signal if the lag time has elapsed.
    Type: Application
    Filed: May 6, 2011
    Publication date: March 13, 2014
    Applicant: Siemens Aktiengesellschaft
    Inventors: Joerg Blumschein, Michael Claus, Volker Henn, Matthias Kereit, Gustav Steynberg, Yilmaz Yelgin
  • Publication number: 20130329321
    Abstract: A power distribution system includes multiple uniform power distribution modules and multiple uniform mating connectors. A portion of the mating connectors are connected to the power distribution modules directly and the remainder are connected to the power distribution modules via a ground fault interrupt adapter.
    Type: Application
    Filed: June 8, 2012
    Publication date: December 12, 2013
    Inventors: Carl A. Wagner, Kyle Stephen Ives, Jeffrey T. Wavering
  • Patent number: 8564916
    Abstract: Various methods and apparatus are described for a photovoltaic system. In an embodiment, a hybrid grounding circuit as well as a ground fault monitoring circuit are in the inverter circuitry with its switching devices that generate three-phase Alternating Current (AC) voltage. The three-phase AC voltage is supplied to a utility power grid interface transformer, where a primary-side common node of the Utility Power grid interface transformer is connected to Earth ground. Each inverter has 1) its own set of isolation contacts to connect as well as isolate this particular inverter from the utility grid interface transformer, and 2) control components in the ground fault monitoring circuit for controlling operation of the isolation contacts based off a presence of the ground fault detected by the ground fault monitor circuit for that inverter. The inverter circuit receives a DC voltage supplied from its own set of ungrounded Concentrated PhotoVoltaic modules.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: October 22, 2013
    Assignee: Western Gas and Electric Company
    Inventors: Hossein Kazemi, Viggo Selchau-Hansen, Brian Hinman
  • Patent number: 8559143
    Abstract: A system and method for a vehicle control system is disclosed herein. The system includes an inverter circuit, a permanent magnet synchronous motor, and a crossover connected between the inverter circuit and the permanent magnet synchronous motor. The system may also include at least one current sensor installed between the inverter circuit and the permanent magnet synchronous motor. A contactor may also be connected between the inverter circuit and the permanent magnet synchronous motor and may pass or shut off electricity between the inverter circuit and the permanent magnet synchronous motor. The system may also include a control unit connected to the contactor and the current sensor. The control unit may detect a current abnormality using information from the current sensor and open the contactor if an abnormality is detected.
    Type: Grant
    Filed: June 21, 2011
    Date of Patent: October 15, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ikuo Yasuoka, Shinichi Toda, Mitsuhiro Numazaki, Hidetoshi Manabe, Takashi Takagi
  • Patent number: 8537509
    Abstract: The present invention relates to a ground fault detecting and controlling method for a parallel-structured high voltage system, and more particularly, such a ground fault detecting and controlling method for a parallel-structured high voltage system, in which it can be more precisely determined whether or not the system operation is emergently stopped based on individual insulation resistance values for respective items of the system, and it can be determined whether there is the possibility of temporary operation of the system in the emergency stop situation of the system operation. According to the present invention, a combined insulation resistance ground fault reference value is calculated based on individual insulation resistance values for respective items of the system, and the entire system is controlled by using the calculated combined insulation resistance ground fault reference value such that a high-accuracy ground fault detecting and controlling method can be provided.
    Type: Grant
    Filed: March 29, 2011
    Date of Patent: September 17, 2013
    Assignee: Hyundai Motor Company
    Inventor: Sang Yon Yoon
  • Patent number: 8537510
    Abstract: For monitoring the isolation of an IT-grid with respect to ground, an inverter connecting a direct current side with an alternating current side of the IT-grid and a photovoltaic device on the direct current side of the IT-grid, at least one isolation resistance of the direct current side with respect to ground is monitored for falling below a resistance threshold value while the inverter is running, and additionally a leakage current via the inverter towards ground is monitored for exceeding a current threshold value.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: September 17, 2013
    Assignee: SMA Solar Technology AG
    Inventor: Reinhard Lehmann
  • Patent number: 8502542
    Abstract: An appliance and a method are intended to monitor a phase line of a section of an electrical energy grid line. The appliance comprises a device for monitoring a parameter of a phase line. The parameter is representative of routine operating conditions of the phase line and has a known propagation speed. The appliance also comprises a device for generating an event detection signal each time the parameter has a value that exceeds a threshold, and for storing a reception time when the detection signal is generated. The appliance also has a device for sending a signal representative of a geographic location of the end of the section and a device for performing a geographic location of the event once two consecutive detection signals are generated from the signal representative of the geographic location, and reception times associated with the two detection signals.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: August 6, 2013
    Assignee: Hydro Quebec
    Inventor: Pierre Couture
  • Patent number: 8432649
    Abstract: Disclosed herein is an abnormal current detection circuit for circuit breaker, comprising a full-wave amplifier, a positive wave-period comparator for comparing a positive wave-period amplification voltage signal with a positive wave-period reference voltage signal to output a pulse signal, a negative wave-period comparator for comparing a negative wave-period amplification voltage signal with a negative wave-period reference voltage signal to output a pulse signal, a combining circuit for combining pulse signals outputted from the positive wave-period comparator and the negative wave-period comparator to output a full-wave combining signal, a reference voltage generator for generating a reference voltage signal, and a comparative driving circuit section for comparing the combining signal with the reference voltage signal to output a signal for controlling a circuit breaker to be driven to a circuit breaking position when the combining signal is greater or equal to the reference voltage signal.
    Type: Grant
    Filed: May 12, 2010
    Date of Patent: April 30, 2013
    Assignee: LS Industrial Systems Co., Ltd.
    Inventor: Jong Kug Seon
  • Patent number: 8390465
    Abstract: A residual-current circuit breaker includes at least one summation current transformer through which at least one first lead and one second lead of a network to be protected are guided. At least one secondary winding is arranged on the summation current transformer and operatively connected at least indirectly with at least one energy storage element. At least one discharging resistor is switched in parallel with the energy storage element. The residual-current circuit breaker has a trip element which is operatively connected with break contacts in the at least one first lead and the at least one second lead. In order to reduce unexpected cut-offs of a network to be protected, the at least one discharging resistor includes a first partial resistor, and a second partial resistor switched in series with respect to the first partial resistor, with a least one electric signaling device operatively connected, at least indirectly, with the first partial resistor.
    Type: Grant
    Filed: June 12, 2009
    Date of Patent: March 5, 2013
    Assignee: Moeller Gebaudeautomation GmbH
    Inventors: Rainer Meisel, Georg Ritzinger
  • Patent number: 8331067
    Abstract: An apparatus and method for providing ground fault protection to a lifting device utilizing an electromagnet and powered by a generator. The apparatus and method rectifies an AC voltage emanating from the generator source and monitors unsafe operating conditions of the generator's circuit wherein operation of the lifting device is ceased when predetermined electrical operating parameters are exceeded.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: December 11, 2012
    Assignee: Ephaugh, Inc.
    Inventor: John Samila
  • Patent number: 8319466
    Abstract: The present invention relates generally to systems and methods for detecting ground faults (i.e., line-to-ground faults) in electrical power conversion systems. In particular, the embodiments described herein include a common mode voltage booster module configured to calculate a common mode voltage boost factor and a common mode voltage boost function based on a plurality of voltage commands for the system. The common mode voltage boost factor and/or the common mode voltage boost function may be applied to the voltage commands to generate boosted voltage commands which, when applied to an inverter or converter, source current indicative of ground faults in the system. More specifically, the common mode voltage boost factor may be multiplied by a common mode voltage calculated by a common mode voltage calculator and summed with the voltage commands.
    Type: Grant
    Filed: February 21, 2011
    Date of Patent: November 27, 2012
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Carlos Rodriguez Valdez, Russel J. Kerkman, Rangarajan Tallam
  • Patent number: 8310090
    Abstract: A differential-current switch includes a first unit arranged in an electric power supply network for detecting a differential current and outputting an analog differential current signal, an analog-to-digital converter receiving the outputted analog differential current signal and converting the outputted analog differential current signal to a digital differential current signal, a first digital signal processing unit receiving the digital differential current signal, a second unit for disconnecting circuit breaker contacts in the electric power supply network, and first means connected upstream of the analog-to-digital converter for adjusting the analog differential current signal. Adjustment of the analog differential current signal provides favorable resolution of a differential current signal over a wide dynamic range.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: November 13, 2012
    Assignee: Moeller Gebäudeautomation GmbH
    Inventors: Georg Ritzinger, Rainer Meisel
  • Patent number: 8289668
    Abstract: Current differential protection with charging current compensation is provided for a power apparatus, such as a power transmission line. Individual terminals dynamically determine their respective contributions, if any, to the charging current compensation value as availability of one or more voltage sources dynamically changes within the power apparatus. Respective terminals calculate local contributions to a charging current compensation value based on local voltage measurements. A loss of a voltage source is handled by adjusting multipliers for the remaining compensation points to reflect the total charging current. A local contribution is suppressed when the local voltage source is no longer available. After applying the local contributions, an alpha plane analysis may be used to determine when to trip the power apparatus.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: October 16, 2012
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Bogdan Z. Kasztenny, Normann Fischer
  • Patent number: 8259423
    Abstract: An automotive vehicle includes a charge port integrated with the vehicle. The charge port includes electrical contacts configured to receive electrical power from an electric grid, and a fault interrupt circuit electrically connected with the electrical contacts.
    Type: Grant
    Filed: July 14, 2009
    Date of Patent: September 4, 2012
    Assignee: Ford Global Technologies, LLC
    Inventors: Allan Roy Gale, Michael W. Degner, Steven F. Chorian, Venkateswa Anand Sankaran
  • Patent number: 8232804
    Abstract: This invention relates to a time alert device (1) for use with an earth leakage protection device comprising a microprocessor system (10) provided with a software controlled alert trigger timer (22). On time out of the alert trigger timer, the microprocessor system (10) initiates an audible and/or visual annunciation to remind the user of the earth leakage protection device to perform integrity test on the earth leakage protection device. If the earth leakage protection device fails the integrity test, the user detects that the earth leakage protection device could be faulty and needs expert attention. If the earth leakage device passes the integrity test, the alert trigger timer is reset for another predetermined time interval to remind the user to perform another integrity test on the earth leakage protection device. The time alert device can be further provided with a message display panel.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: July 31, 2012
    Inventor: See Ni Fong
  • Publication number: 20120140365
    Abstract: An intelligent electronic device may provide restricted earth fault protection to components of an electrical power delivery system using both an amplitude comparator and a phase angle comparator configured to independently detect faults. The IED may include selection logic configured to select the output of one of the phase angle comparator and the amplitude comparator, to the exclusion of the other, based on system conditions. Accordingly, when system conditions are such that a phase angle comparator is better suited to detect a fault, selection logic may select the output of the phase angle comparator. Similarly, when system conditions are such that an amplitude comparator may better detect a fault, selection logic may select the output of the amplitude comparator. A protection system may further include an in-zone fault detector configured to detect in-zone faults.
    Type: Application
    Filed: December 2, 2010
    Publication date: June 7, 2012
    Inventor: Casper A. Labuschagne
  • Patent number: 8174804
    Abstract: A circuit breaker apparatus may be used to interrupt overcurrent and ground fault in a circuit. The circuit breaker apparatus may include an overcurrent coil for tripping the circuit breaker apparatus, a voltage coil also for tripping the circuit breaker apparatus located proximate to the overcurrent coil, ground fault electronics connected to the voltage coil and structured to detect a ground fault in the circuit when the ground fault exceeds a threshold level, and a solid state switch. The ground fault electronics can be structured to send a trip signal to close the solid state switch when a ground fault is detected, the solid state switch is configured to force a current through the voltage coil when the solid state switch is closed, the current being of sufficient magnitude to trip the circuit breaker apparatus.
    Type: Grant
    Filed: November 12, 2010
    Date of Patent: May 8, 2012
    Assignee: Carling Technologies, Inc.
    Inventor: Michael Fasano
  • Patent number: 8139328
    Abstract: There is disclosed a circuit interrupting device with symmetrical inputs comprising a first input configured for connection to a power source or a load circuit and a second input configured for connection to a power source. There are a plurality of electrical conductors extending from the first and second inputs and a third input configured for connection to a load provided by a user. There is also a first set of transformers comprising at least one differential transformer and at least one neutral transformer connected to detect leakage current in a load circuit coupled to the first set of terminals. There is also a second set of transformers comprising at least one additional differential transformer and at least one additional neutral transformer connected to detect leakage current in a load circuit coupled to the second set of terminals.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: March 20, 2012
    Assignee: Levitron Manufacturing Company, Inc.
    Inventors: Nicholas L. DiSalvo, James A. Porter
  • Patent number: 8072715
    Abstract: An apparatus is provided for fault protection. The apparatus may include one or more electronic components configured to receive a single phase-to-ground fault signal and a double phase-to-ground fault signal subsequent to receiving the single phase-to-ground fault signal. The one or more of electronic components may be further configured to provide for a delay while the single phase-to-ground fault signal indicates that a single phase-to-ground fault is present on the ungrounded power system and the double phase-to-ground fault signal indicates that the double phase-to-ground fault is present on the ungrounded power system. The delay may allow for an opportunity to isolate a phase-to-ground fault on a first phase from a phase-to-ground fault on a second phase. Associated methods and computer program products are also provided.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: December 6, 2011
    Assignee: Huntington Ingalls Incorporated
    Inventors: Louis V. Dusang, Jr., Jeffrey B. Roberts
  • Patent number: 8064174
    Abstract: A circuit is disclosed for disconnecting a power source upon the detection of a leakage current comprising a power cable having an insulated first and a second wire. The power cable has a conductive shield surrounding the first and second wires with a drain wire electrically contacting the conductive shield. A disconnect switch is interposed between the power source and the power cable. A primary circuit controls the disconnect switch. A secondary circuit is connected to the drain wire for sensing a leakage current between the conductive shield and one of the first and second wires. An optical switch interconnects the primary circuit and the secondary circuit for opening the disconnect switch upon the secondary circuit sensing a leakage current.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: November 22, 2011
    Assignee: Technology Research Corporation
    Inventors: Thomas S. Williams, Frank S. Brugner, Jr., Paul R. Gandolfi
  • Patent number: 8045303
    Abstract: A ground fault interrupter to be used by utility company while effecting repairs to the electrical service for a building is positioned to interrupt the power supply to the building in case of a detected ground fault and utilizes a sensor for detecting the fault current at the service entrance to a building; a contact switch, selectively movable between open and closed positions, mounted for temporary use in series with said power supply to the building; and a microprocessor based circuit for measuring and evaluating fault current detected by the sensor and controlling the selective movement of the contact switch between its open and closed positions.
    Type: Grant
    Filed: May 6, 2009
    Date of Patent: October 25, 2011
    Assignee: The Von Corporation
    Inventors: Ricky Curl, Fred von Herrmann
  • Patent number: 8018697
    Abstract: A switching circuit, e.g. an RCD, comprises a pair of mechanical contacts (M) in an alternating current electricity supply (N, L) and circuit means (SCR) for opening the contacts to cut off the supply in response to a switching signal (S). The switching circuit includes further circuit means (Rs, Cs, D2, D3, Q1, Q2) for defining successive periods of time (“activation windows”) during which the magnitude of the supply voltage is not at a maximum and allowing the contacts to open in response to a switching signal only during such windows.
    Type: Grant
    Filed: February 7, 2007
    Date of Patent: September 13, 2011
    Assignee: Shakira, Limited
    Inventor: Patrick Ward
  • Publication number: 20110199707
    Abstract: Various methods and apparatus are described for a photovoltaic system. In an embodiment, a hybrid grounding circuit as well as a ground fault monitoring circuit are in the inverter circuitry with its switching devices that generate three-phase Alternating Current (AC) voltage. The three-phase AC voltage is supplied to a utility power grid interface transformer, where a primary-side common node of the Utility Power grid interface transformer is connected to Earth ground. Each inverter has 1) its own set of isolation contacts to connect as well as isolate this particular inverter from the utility grid interface transformer, and 2) control components in the ground fault monitoring circuit for controlling operation of the isolation contacts based off a presence of the ground fault detected by the ground fault monitor circuit for that inverter. The inverter circuit receives a DC voltage supplied from its own set of ungrounded Concentrated PhotoVoltaic modules.
    Type: Application
    Filed: February 15, 2011
    Publication date: August 18, 2011
    Applicant: GREENVOLTS, INC
    Inventors: HOSSEIN KAZEMI, VIGGO SELCHAU-HANSEN, BRIAN HINMAN
  • Publication number: 20110149448
    Abstract: A short-circuit distance relay is provided which has a high accuracy and an excellent reliability such that the relay can determine the fault phase based on impedance values measured by each phase, prevent misjudgment and unnecessary operation due to overreach without depending on the power system conditions, and operate even if multiple faults occur. An impedance calculation part (11) calculates an impedance value of the phase in which the direction element (SM) has operated. A minimum phase selection part (12) selects as a fault phase, the phase having a minimum impedance value. When the impedance value of the selected phase is equal to or less than the setting impedance value of the distance element of the phase, an output of the distance element of the phase is made to be valid to output an opening command to a circuit breaker. As a result, it is possible to prevent misjudgment and unnecessary operation due to overreach without depending on the power system conditions.
    Type: Application
    Filed: August 28, 2009
    Publication date: June 23, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masao Hori, Yutaka Saita, Michihiko Inukai
  • Patent number: 7965478
    Abstract: A system and method for detecting a fault condition by a relay is provided. The system includes means for detecting phase currents through three electrical phases, means for detecting a ground fault current, a processor configured to perform a current-based function based upon at least one of the phase currents and a filter. The processor is configured to perform current-based functions based on whether the filter is enabled or disabled.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: June 21, 2011
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Steven T. Haensgen, William H. Martin, Ricky A. Hurley, Ronald N. Jansen
  • Patent number: 7948723
    Abstract: An exemplary ground fault detection device is capable of detecting a ground fault on multiple phases. The ground fault detection device includes a monitoring module that monitors the phases and determines if there is a non-zero electrical energy value sum for a selected interval on each phase. An output module provides a ground fault indication when all of the phases have a non-zero electrical energy sum for the selected interval.
    Type: Grant
    Filed: February 18, 2008
    Date of Patent: May 24, 2011
    Assignee: Hamilton Sundstrand Corporation
    Inventor: Dennis R. Anderson
  • Patent number: 7948722
    Abstract: A differential protection device comprising: differential current measuring means, processing means connected to the measuring means and comprising operating rating selection means and time delay selection means to select tripping curves, actuating means, and test means connected to the measuring means. In the protection device the test means are associated with the operating rating selection means and with the time delay selection means to select a minimum or reduced operating rating and to select a minimum or reduced time delay when said test means are actuated.
    Type: Grant
    Filed: November 27, 2007
    Date of Patent: May 24, 2011
    Assignee: Schneider Electric Industries SAS
    Inventor: Mustapha Chelloug
  • Patent number: 7944654
    Abstract: A multi-pole circuit breaker for a power distribution system having multiple line conductors carrying AC currents that are out of phase with each other, and a common neutral conductor, comprises first and second current sensors, a ground fault detection circuit, and an arcing fault detection circuit. The first current sensor is adapted to be coupled to both of the line conductors and to the neutral conductor and produces a first output signal indicative of the resultant of the electrical currents flowing in the line and neutral conductors. The ground fault detection circuit receives the first output signal and produces a trip signal in response to the detection of a ground fault.
    Type: Grant
    Filed: November 10, 2008
    Date of Patent: May 17, 2011
    Inventors: Gary W. Scott, Randall J. Gass