Transformer Patents (Class 324/547)
  • Patent number: 11156671
    Abstract: A method for performing diagnostics on a target transformer includes applying a voltage output of a voltage generator to a winding or phase of the target transformer; controlling the voltage generator to output an AC voltage at a first frequency and then a second frequency and measuring first and second excitation currents flowing into the target transformer associated with the first frequency and second frequency, respectively. The method further includes determining an actual excitation current of the target transformer as a function of both the first and second excitation currents, and comparing the actual excitation current of the target transformer to excitation currents associated with one or more benchmark transformers having known electrical characteristics.
    Type: Grant
    Filed: January 24, 2020
    Date of Patent: October 26, 2021
    Assignee: DOBLE ENGINEERING COMPANY
    Inventor: Mark F. Lachman
  • Patent number: 11137312
    Abstract: An integrated fault monitoring apparatus for electrical devices has an internal fault detector for detecting transient pressure surges within the electrical device, a pressure relief valve for allowing release of pressure during normal operating conditions of the electrical device, a temperature indicator for indicating that an operating temperature of the electrical device has gone above a predetermined threshold, and/or a sudden pressure relief device for allowing air to escape from the electrical device in the event of a sudden and significant increase in pressure within the electrical device. Methods of using the apparatus are provided.
    Type: Grant
    Filed: February 19, 2020
    Date of Patent: October 5, 2021
    Assignee: IFD INTERNAL FAULT DETECTOR CORP.
    Inventors: Justin George Pezzin, Jeremy Michael Van Horn, Yen-You Lin, John Paul Chisholm, Sophie Anne Ramsden
  • Patent number: 11092638
    Abstract: An impulse tester according to the present invention includes a first terminal, a second terminal, a voltage generation circuit, and an oscillation suppression circuit. The oscillation suppression circuit includes a discharge switch and a capacitor. The discharge switch has a first electrode and a second electrode. The first electrode is connected to the first terminal. The second electrode is disposed at a spacing from the first electrode. The discharge switch becomes conductive when a voltage difference between the first electrode and the second electrode is greater than a discharge voltage corresponding to the spacing between the first electrode and the second electrode. The capacitor is connected between the second electrode and the second terminal.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: August 17, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Akitoshi Ito, Kazuaki Aono
  • Patent number: 10969425
    Abstract: A semiconductor integrated circuit includes: a main circuit; a non-volatile memory; and a self-diagnosis circuit configured to execute, when the semiconductor integrated circuit is to be powered off, self-diagnosis processing in which the main circuit is diagnosed and a diagnosis execution record indicating whether the diagnosis is completed and a diagnosis result indicating a result of the diagnosis are stored in the non-volatile memory. The self-diagnosis circuit is configured to: determine, when the semiconductor integrated circuit is powered on, whether there is a failure in the main circuit by reading the diagnosis execution record and the diagnosis result out of the non-volatile memory; and shift a state of the main circuit to a safe state when determining that there is a failure in the main circuit, and instruct the main circuit to start normal operation when determining that there is no failure in the main circuit.
    Type: Grant
    Filed: June 17, 2019
    Date of Patent: April 6, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hideki Shimauchi, Akio Kamimurai
  • Patent number: 10914778
    Abstract: A transformer testing device (10) comprises outputs (31-33) for detachably connecting the transformer testing device to windings of multiple phases of a transformer (50). The transformer testing device (10) further comprises a plurality of sources (21-23), each of which is designed to generate a test signal. The transformer testing device (10) also comprises a switching matrix (40) that is connected between the plurality of sources (21-23) and the outputs (31-33).
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: February 9, 2021
    Assignee: OMICRON ELECTRONICS GMBH
    Inventors: Dirk Flax, Markus Pütter
  • Patent number: 10884075
    Abstract: A printed circuit board, a method for determining an engagement state between the printed circuit board and a flexible printed circuit, and a display device are provided. The printed circuit board includes a substrate, a connector fixed on the substrate, and configured to be connected with the flexible printed circuit, and a determining circuit connected with the connector. The secondary pin is added to the connector, and can determine together with the determining circuit, added to the substrate, connected with the secondary pin, an engagement state between the first pins of the connector, and the second pins of the flexible printed circuit.
    Type: Grant
    Filed: August 1, 2018
    Date of Patent: January 5, 2021
    Assignees: CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD., BOE TECHNOLOGY GROUP CO., LTD.
    Inventors: Bing Xu, Tao Hou, Junping Bao, Xinghua Li
  • Patent number: 10768237
    Abstract: A motor driving device includes: a converter unit having a capacitor; a plurality of inverter units having a plurality of semiconductor switching elements and configured to convert a capacitor voltage across the capacitor into an AC voltage to drive a plurality of motors; a second switch configured to connect the negative-side terminal of the capacitor to ground; a first detector configured to detect a ground-referenced voltage; and a second detector configured to detect the capacitor voltage. The motor driving device controls the semiconductor switching elements to establish a measurement state for enabling measuring of the insulation resistance of a measurement target motor, estimates a convergence value of the ground-referenced voltage based on multiple measurements of the ground-referenced voltage detected by the first detector, and then calculates the insulation resistance based on the estimated convergence value and the capacitor voltage.
    Type: Grant
    Filed: November 27, 2018
    Date of Patent: September 8, 2020
    Assignee: FANUC CORPORATION
    Inventors: Norihiro Chou, Youichirou Ooi
  • Patent number: 10761149
    Abstract: Methods and apparatus for energizing a wound component are described. In one arrangement, a method of energizing a component with an alternating voltage is provided. The component comprises a coil wound on a magnetic core. The method comprises applying a voltage across the coil that has a first waveform during a first time period and a second waveform during a second time period. The second time period is subsequent to the first time period. The second waveform comprises an oscillating function comprising a sequence of identical waveforms. The first waveform is such that if the coil had zero electrical resistance the variation of flux density in the magnetic core with time would change sign at least once during the first waveform.
    Type: Grant
    Filed: August 16, 2016
    Date of Patent: September 1, 2020
    Assignee: VOLTECH INSTRUMENTS, LTD.
    Inventors: John Stewart Ford, Lionel Ind
  • Patent number: 10759470
    Abstract: A sensor device includes a sensor section having a plurality of sensor elements sensing a physical quantity regarding a magnetic flux collecting module, an output circuit generating and outputting an output signal including data signals respectively corresponding to sensing values from the sensor elements, and an ECU obtaining the output signal. The ECU includes an abnormality determiner identifying an abnormal sensor element. When at least two of the plurality of sensor sections respectively have at least one normal sensor element, a sub-sensor section transmits the output signal therefrom to the ECU at a shifted output timing from an output timing of the output signal from a main sensor section. The amount of such a shift of the output timing is shorter than one signal cycle of the output signal.
    Type: Grant
    Filed: May 18, 2016
    Date of Patent: September 1, 2020
    Assignee: DENSO CORPORATION
    Inventors: Shuji Kuramitsu, Katsuhiko Hayashi, Takaharu Kozawa, Koichi Nakamura, Masaya Taki, Toshimitsu Sakai
  • Patent number: 10641817
    Abstract: A motor driving device includes: a converter unit having a capacitor; a plurality of inverter units having a plurality of semiconductor switching elements and configured to convert a capacitor voltage across the capacitor into an AC voltage to drive a plurality of motors; a second switch configured to connect the negative-side terminal of the capacitor to ground; a first detector configured to detect a ground-referenced voltage; and a second detector configured to detect the capacitor voltage. The motor driving device controls the semiconductor switching elements to establish a measurement state for enabling measurement of an insulation resistance of a measurement target motor, determines that the ground-referenced voltage has converged when an amount of change in the waveform of the ground-referenced voltage detected by the first detector becomes equal to or lower than a threshold, and calculates the insulation resistance based on the ground-referenced voltage and the capacitor voltage.
    Type: Grant
    Filed: November 26, 2018
    Date of Patent: May 5, 2020
    Assignee: FANUC CORPORATION
    Inventors: Norihiro Chou, Youichirou Ooi
  • Patent number: 10605849
    Abstract: An integrated fault monitoring apparatus for electrical devices has an internal fault detector for detecting transient pressure surges within the electrical device, a pressure relief valve for allowing release of pressure during normal operating conditions of the electrical device, a temperature indicator for indicating that an operating temperature of the electrical device has gone above a predetermined threshold, and/or a sudden pressure relief device for allowing air to escape from the electrical device in the event of a sudden and significant increase in pressure within the electrical device. Methods of using the apparatus are provided.
    Type: Grant
    Filed: February 19, 2016
    Date of Patent: March 31, 2020
    Assignee: IFD Internal Fault Detector Corp.
    Inventors: Justin George Pezzin, Jeremy Michael Van Horn, Yen-You Lin, John Paul Chisholm, Sophie Anne Ramsden
  • Patent number: 10545183
    Abstract: A method for performing diagnostics on a target transformer includes applying a voltage output of a voltage generator to a winding or phase of the target transformer; controlling the voltage generator to output an AC voltage at a first frequency and then a second frequency and measuring first and second excitation currents flowing into the target transformer associated with the first frequency and second frequency, respectively. The method further includes determining an actual excitation current of the target transformer as a function of both the first and second excitation currents, and comparing the actual excitation current of the target transformer to excitation currents associated with one or more benchmark transformers having known electrical characteristics.
    Type: Grant
    Filed: January 29, 2019
    Date of Patent: January 28, 2020
    Assignee: Doble Engineering Company
    Inventor: Mark F. Lachman
  • Patent number: 10527675
    Abstract: A motor driving device includes: an insulation resistance measuring unit configured to measure insulation resistance of a motor selected as a measurement target to thereby measure the insulation resistance of each of the multiple motors; a measurement interrupting unit configured to interrupt measurement of insulation resistance if a measurement interrupt condition is established; a storage unit configured to store information indicating the motor selected as the measurement target at the time of interruption of the measurement of insulation resistance; and a measurement resuming unit configured to, when measurement is resumed, resume measurement of the insulation resistance sequentially from the motor that had been selected as the measurement target when the measurement was interrupted, based on the information stored in the storage unit.
    Type: Grant
    Filed: December 3, 2018
    Date of Patent: January 7, 2020
    Assignee: FANUC CORPORATION
    Inventors: Norihiro Chou, Youichirou Ooi
  • Patent number: 10345367
    Abstract: Fault-indicator assemblies that can each be mounted externally to a corresponding electronic device to provide a visual indication that an internal fault has occurred within the electronic device. A fault-indicator assembly of the present disclosure can be configured for electrical devices such as electrical power transformers, capacitors, and reactors, among others. Some embodiments can be configured to connect to existing orifices of a conventionally manufactured electronic device, such as an orifice for a conventional pressure-relief valve. Such embodiments can be deployed without any modifications to the electrical devices and can be readily retrofitted to existing electrical devices. In some embodiments, a pressure-relief valve can be integrated with the fault-indicator assembly to provide both fault-indication functionality and pressure-relief functionality in the same assembly.
    Type: Grant
    Filed: November 1, 2018
    Date of Patent: July 9, 2019
    Assignees: Orto de Mexico, S.A. de C.V., Weidmann Holding AG
    Inventor: Jorge Gonzalez de la Vega Rosales
  • Patent number: 10209293
    Abstract: A sensor to monitor health of surge arresters such as metal oxide arresters is disclosed. The sensor including a housing; a sensor assembly contained in the housing, and a voltage measurement strap extending around a periphery of the housing. The voltage measurement strap being electrically connected to the electronics board and configured to measure voltage using electric field. The sensor assembly including: an electronics board to receive, transmit, process, and store signals; a Rogowski coil electrically connected to the electronics board to measure surge currents diverted by the surge arrestor; and a current transformer electrically connected to the electronics board to measure leakage current.
    Type: Grant
    Filed: July 11, 2017
    Date of Patent: February 19, 2019
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Andrew John Phillips, Christiaan Engelbrecht, Robert Carlton Lynch, J. Mark Major
  • Patent number: 10180451
    Abstract: A system for monitoring an electric power delivery system by obtaining high-frequency electric power system measurements and displaying event information is disclosed herein. The system may use the high-frequency electric power system information to detect traveling waves. The system may generate a display showing fault location on the electric power system, and timing of traveling waves received at locations on the electric power system. The display may include time on one axis and location on another axis. The display may include a waterfall display.
    Type: Grant
    Filed: October 13, 2016
    Date of Patent: January 15, 2019
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Edmund O. Schweitzer, III, Veselin Skendzic, Cody W. Tews, David E. Whitehead
  • Patent number: 10088516
    Abstract: Embodiments of the disclosure relate to detecting turn-to-turn faults in one or more windings of various objects. In one implementation, a fault detector uses a differential protection algorithm to detect a turn-to-turn fault in a winding of a three-phase shunt reactor. Various voltage and current measurements carried out upon the three-phase shunt reactor are used to calculate a difference value between a voltage-based parameter and a current-based parameter. The voltage-based parameter is indicative of a normalized negative voltage imbalance and the current-based parameter is indicative of a normalized negative current imbalance. A turn-to-turn winding fault is declared when the difference value is not equal to zero.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: October 2, 2018
    Assignee: General Electric Company
    Inventors: Zhiying Zhang, Sarasij Das, Tarlochan Sidhu, Mohammad Reza Dadash Zadeh
  • Patent number: 10073130
    Abstract: A method of determining a reduction of remaining service lifetime of an electrical device during a specific time period. The method comprising the steps of providing a measurement system comprising a temperature measurement device; a current measurement device and a voltage measurement device; measuring a temperature value, voltage values and current values by using the measurement device; determining a harmonic load based on the current values; determining a reduced maximum operating temperature based on the harmonic load; determining an amount of transient over-voltages based on the voltage values; determining a transient aging factor based on the amount of transient over-voltages; determining a temperature dependent aging factor based on the temperature value and the reduced maximum operating temperature; and determining the reduction of remaining service life based on the specific time period, the transient aging factor and the temperature dependent aging factor.
    Type: Grant
    Filed: October 5, 2015
    Date of Patent: September 11, 2018
    Assignee: LANDIS+GYR AG
    Inventors: Joe Imfeld, Andreas Rumsch, Patrick Schmid
  • Patent number: 10065001
    Abstract: The invention relates to an apparatus, in particular for ejecting a fluid, having an electric motor (500), the motor comprising at least one motor winding (506a-d), having a control unit (656) for controlling the motor (500), wherein the apparatus further comprises an electronic detection circuitry (620) configured to determine an electrical quantity, the electrical quantity being a function of the electric resistance (Rw) of the motor winding (506a-d), and wherein the control unit (656) is configured to control the motor (500) as a function of the electrical quantity. The invention further relates to a method for controlling such an apparatus, comprising the steps of: determining an electrical quantity, the electrical quantity being a function of the electric resistance (Rw) of the motor winding (506a-d); and controlling the motor (500) as a function of the electrical quantity.
    Type: Grant
    Filed: October 30, 2014
    Date of Patent: September 4, 2018
    Assignee: Sanofi-Aventis Deutschland GmbH
    Inventors: Christian Nessel, Barry Yates, David Moore
  • Patent number: 9838228
    Abstract: There are provided a device for removing partial discharge noise and a method of diagnosing the same.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: December 5, 2017
    Assignee: KOREA ELECTRIC POWER CORPORATION
    Inventors: Kwang Sik Choi, Jung Cheol Seo
  • Patent number: 9835686
    Abstract: The invention relates to a method for monitoring an on-load tap changer that is used to switch between winding taps of a tapped transformer without interrupting the load current and is actuated using a motor drive. According to the invention, prior to the actual load switching process, the on-load tap changer is initially moved a short distance, preferably against the direction in which the load is subsequently switched. In said initial process, it is verified whether the on-load tap changer has moved, i.e. has left its previous stationary position, and/or whether the torque on the motor drive has exceeded a predefined threshold value. The actual load switching process takes place only once the test has yielded a positive result.
    Type: Grant
    Filed: March 25, 2013
    Date of Patent: December 5, 2017
    Assignee: MASCHINENFABRIK REINHAUSEN GMBH
    Inventors: Alfred Bieringer, Harald Hochmuth, Dominik Plitzko, Sebastian Schmid
  • Patent number: 9829542
    Abstract: A power monitoring circuit and method for detecting deviations in the output of a power supply. The power monitor is configured to detect and measure two different types of deviations: transient deviations short surges or spikes in the current drawn by the device being powered and prolonged deviations over a threshold current that may be intentional, temporary increases in the output of the power supply. The power monitor collects information such as the number of each type of deviation, the duration of each deviation and the peak current describing identified deviations. This collected information can then be used, especially during the development phase, to locate the root cause of the deviation. The components of the power monitor used to detect and measure these deviations may be disabled and enabled as needed.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: November 28, 2017
    Assignee: MICROCHIP TECHNOLOGY INCORPORATED
    Inventor: Lynn Russell Kern
  • Patent number: 9772362
    Abstract: A tester for testing a transformer is provided. The tester comprises a primary voltmeter and a plurality of secondary voltmeters. The tester may also comprise an ammeter in series with a voltage source configured to apply voltage to the transformer. The primary voltmeter is configured to measure voltage induced across a primary winding of the transformer, while the secondary voltmeters may simultaneously measure voltage outputs at secondary windings of the transformer. The tester is configured to calculate ratios, saturation curves, and knee points for multiple winding combinations based on the measurements simultaneously obtained by the ammeter and the primary and secondary voltmeters.
    Type: Grant
    Filed: September 4, 2015
    Date of Patent: September 26, 2017
    Assignee: AVO Multi-Amp Corporation
    Inventors: David Hembree Milner, John Leonard Shanks, Harvey Wayne Veselka, Jr.
  • Patent number: 9744866
    Abstract: An electric power control device has a first connector connected to a second connector provided in a second appliance, and a control circuit provided within a first appliance that exchanges electric power with the second appliance via a harness and connected to the first connector via the harness. The first connector includes a latching solenoid that switches connector connection, i.e., connection between the first and second connectors, between a locked state and an unlocked state. The control circuit outputs a first or second voltage to an operating coil inside the latching solenoid to bring the connector connection into the locked or unlocked state, respectively.
    Type: Grant
    Filed: May 29, 2015
    Date of Patent: August 29, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventor: Kohzaburoh Murakami
  • Patent number: 9726706
    Abstract: System and method for detecting turn-to-turn faults in one or more windings of various objects are provided. In one implementation, a fault detector receives a set of current measurements associated with a transformer and uses these measurements to execute a procedure for detecting a turn-to-turn fault in the transformer.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: August 8, 2017
    Assignee: General Electric Company
    Inventors: Zhiying Zhang, Sarasij Das, Tarlochan Sidhu, Mohammad Reza Dadash Zadeh
  • Patent number: 9726708
    Abstract: The present invention relates to a device for detecting a partial discharge for a power transformer which detects an electromagnetic signal occurring due to faulty insulation. The device includes an antenna unit receiving electromagnetic waves, an insulator including the antenna unit, a metallic air-tight unit that seals a connector connected to the insulator and connecting a coaxial cable, and the coaxial cable exposed to the outside of the metallic air-tight unit. Thus, it is possible to enhance broadband properties through an internal conductor of a drain valve.
    Type: Grant
    Filed: December 24, 2012
    Date of Patent: August 8, 2017
    Assignee: HYOSUNG CORPORATION
    Inventors: Jae-Ryong Jung, Eun-Tae Ryu, Kyung-Rok Hwang
  • Patent number: 9693244
    Abstract: A sensor system in which it is possible to identify a sufficient number of sensors even in a situation where the data length of a packet is limited, as well as a sensor and a receiving device in the same, are provided. A sensor repeating a measurement period for performing measurement and a transmission period for performing transmission at predetermined cycles, includes: a measurement section (11) that outputs during the measurement period measurement information based on predetermined measurement; and a transmission section (12) that transmits during the transmission period, by using a single packet or a plurality of packets, source identification information for identifying a source of a packet, the measurement information, and sensor-related information for identifying the sensor and/or a measurement target equipment of this sensor.
    Type: Grant
    Filed: May 24, 2012
    Date of Patent: June 27, 2017
    Assignee: NEC Corporation
    Inventors: Kenichi Maruhashi, Shingo Takahashi, Noriyuki Itabashi, Nobuhide Yoshida
  • Patent number: 9581637
    Abstract: An apparatus for measuring winding resistances of windings in a delta-connected transformer includes at least a first and a second DC current source connected each between the phase ends of a first and a second leg respectively of the primary side of the transformer and at least a third DC current source connected between two nodes of the secondary side of the transformer. Furthermore, a method for measuring a winding resistance of windings in delta-connected transformers includes the steps of applying a first and a second measuring current to each one of two corresponding legs, applying a third measuring current between two nodes of a pair of windings on the secondary side and measuring at least a winding resistance of the winding between said nodes on the secondary side of the transformer and/or the winding resistance of a leg of the primary side as soon as an inductive voltage drop in the windings substantially equals zero.
    Type: Grant
    Filed: May 7, 2012
    Date of Patent: February 28, 2017
    Assignee: Haefely Test AG
    Inventor: Marc Muller
  • Patent number: 9529032
    Abstract: The invention relates to a method and a device (1) for the online-detection of a deterioration in the state of an insulation in an electric machine (2). A stepped voltage is applied to the winding(s) (3) of the machine (2) with the aid of a converter (41), and the current (i) induced in this manner, and/or the time derivative (di/dt) thereof, is acquired as a measurement signal with the aid of at least one sensor (6, 7, 8) and is then oversampled with a frequency higher than the frequencies characteristic for settling. The signal obtained by said oversampling is then evaluated with regard to parameters of the settling process such as overshooting (Ah) and/or natural frequency (1/?T) and/or a damping constant, in order to detect any deterioration in the insulation.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: December 27, 2016
    Assignee: TECHNISCHE UNIVERSITAT WIEN
    Inventor: Thomas Wolbank
  • Patent number: 9400305
    Abstract: An instrument for detecting partial electric discharges includes: an input stage set up to receive a discharge signal representative of one or more partial discharge pulses and a sync signal representative of an alternating voltage applied to the electric apparatus; a data processing stage for receiving the discharge signal and the sync signal, and extracting substantially in real time for each pulse detected the value of an amplitude parameter, correlated with a pulse amplitude, and the value of a phase parameter, representative of the phase of the voltage applied to the electric apparatus concurrently with the pulse, and transferring to output a processed digital signal including the values extracted. The processing stage includes a filtering module set up to disable substantially in real time the transfer to output of the values of the parameters extracted for one or more pulses.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: July 26, 2016
    Assignee: TECHIMP HQ S.R.L.
    Inventors: Fabiano Bettio, Gian Carlo Montanari
  • Patent number: 9400304
    Abstract: This disclosure relates to the field of current transformers, for testing the excitation characteristic of a current transformer is disclosed. The method comprise applying alternately positive and negative DC voltages across terminals of secondary winding of a CT to be tested and acquiring a secondary current; constructing a mathematical model of the relationship between the secondary current and a root mean square (rms) equivalent voltage at rated frequency of the CT from the relationship between a magnetic flux of a secondary winding iron-core of the CT and the rms equivalent voltage; and generating an excitation characteristic curve according to the mathematical model. The method and apparatus of the embodiments may test CTs requiring lower testing voltage as well as CTs with knee-point up to tens of kV by supplying a relatively low voltage and power, which makes the embodiments widely applicable.
    Type: Grant
    Filed: April 24, 2013
    Date of Patent: July 26, 2016
    Assignee: Ponovo Power Co., Ltd.
    Inventors: Yake Li, Wei Chen, Sen Zhang, Jingfeng Zhao
  • Patent number: 9247402
    Abstract: A monitoring system for detecting earth faults in an electrical power supply grid providing a power signal includes a plurality of monitoring devices, each of the monitoring devices including a detector for detecting the level of harmonics in the power signal, wherein the level of harmonics is detected in a specific frequency range. Each of the monitoring devices further includes a memory for storing a harmonics reference value, a processor for comparing the detected level of harmonics with the reference level, and a communication device for transmitting an alarm if the detected level of harmonics is above the reference level for a specific period of time. Each of the detectors includes an optical sensor for detecting the harmonics by use of the Faraday effect.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: January 26, 2016
    Assignee: POWERSENSE A/S
    Inventor: Lars N. Bjorn
  • Patent number: 9176195
    Abstract: A method of detecting battery degradation level detects charging and discharging current flow in the battery and determines battery degradation level (state of health, SOH) from the charging and discharging current. The method detects the battery degradation level (SOH) from the root-mean-square of the charging and discharging current flow (Irms) in the battery, which is designated effective current.
    Type: Grant
    Filed: December 27, 2011
    Date of Patent: November 3, 2015
    Assignee: SANYO ELECTRIC CO., LTD.
    Inventor: Reizo Maeda
  • Patent number: 9099913
    Abstract: A method and a device for estimating the winding clamping force on a winding package of a transformer or a reactor, the winding package comprising at least one winding with connections and an iron core. The device includes a current pulse generator configured to generate a current pulse sufficient to excite the winding, means for supplying the current pulse to the winding, a sensor for measuring vibrations of the transformer or the reactor generated by the current pulse, and a computing unit configured to calculate a mechanical resonant frequency based on the measured vibrations and to estimate the clamping forces on the winding packages based on the calculated mechanical resonant frequency and a predetermined relation between the expected mechanical resonant frequency and the clamping force.
    Type: Grant
    Filed: November 12, 2010
    Date of Patent: August 4, 2015
    Assignee: ABB RESEARCH LTD.
    Inventors: Torbjorn Wass, Tord Bengtsson
  • Patent number: 9030209
    Abstract: A failure detecting apparatus that detects an isolation failure between a plurality of coils included in a signal detection apparatus. The failure detecting apparatus includes a voltage applying unit that applies a DC voltage to a coil in the plurality of coils; a differential signal generating unit that generates a differential signal from a voltage at the coil and a predetermined voltage; a threshold voltage setting circuit that outputs a threshold voltage; and a comparator that compares the differential signal with the threshold voltage, thereby detecting whether or not an isolation failure exists. The differential signal generating unit includes either first setting unit for setting an absolute value of the differential signal to be amplified with a predetermined gain or second setting unit for setting the predetermined voltage to be different from a ground potential, and the predetermined gain is set to a value different from one and zero.
    Type: Grant
    Filed: October 8, 2012
    Date of Patent: May 12, 2015
    Assignee: Denso Corporation
    Inventor: Yosuke Asako
  • Patent number: 9018962
    Abstract: A protective system far a power transformer having a neutral line connected to ground where large currents can flow in the neutral line due to electro-magnetic disturbances. The system includes circuitry for: (a) sensing the current level in the neutral line and whether it exceeds a predetermined threshold for a predetermined period; and (b) sensing and processing the harmonic content of the load current and determining the existence of certain relationships of the “even” and “odd” harmonics. Signals, including alarms, indicative of excessive conditions are produced. The system may also include circuitry for sensing the load current level and generating a signal alarm if the load level is above a given value when the harmonics and the DC current have values in excess of certain predetermined values.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: April 28, 2015
    Assignee: Advanced Power Technologies, Inc
    Inventors: Gary R. Hoffman, Edward S. Kwon, Hong Cai
  • Publication number: 20150091598
    Abstract: The transformer fault detection apparatus includes an integrated sensor unit for sensing signals through a plurality of sensors located on each of upper and lower drain valves in a transformer. A first possible discharge area calculation unit calculates a first possible discharge area estimated to be a location of a partial discharge source of the transformer, based on arrival times of signals sensed by different sensors located on the upper drain valve. A second possible discharge area calculation unit calculates a second possible discharge area estimated to be the location of the partial discharge source, based on arrival times of signals sensed by different sensors located on the lower drain valve. A final possible discharge area calculation unit calculates a final possible discharge area, based on an overlapping area between the first and second possible discharge areas.
    Type: Application
    Filed: August 12, 2014
    Publication date: April 2, 2015
    Inventors: Kison HAN, Jinyul YOON, Hyungjun JU, Kijung ANN
  • Patent number: 8949054
    Abstract: A monitoring system for detecting earth faults in an electrical power supply grid providing a power signal includes a plurality of monitoring devices, each of the monitoring devices including a detector for detecting the level of harmonics in the power signal, wherein the level of harmonics is detected in a specific frequency range. Each of the monitoring devices further includes a memory for storing a harmonics reference value, a processor for comparing the detected level of harmonics with the reference level, and a communication device for transmitting an alarm if the detected level of harmonics is above the reference level for a specific period of time. Each of the detectors includes an optical sensor for detecting the harmonics by use of the Faraday effect.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: February 3, 2015
    Assignee: Powersense A/S
    Inventor: Lars N. Bjørn
  • Patent number: 8897635
    Abstract: A signal is conducted from a controller module onto a network via a first coupling. The signal is transmitted across the network and received at one or more receiver modules via one or more second couplings. At the one or more receiver modules, the received signal is analyzed and based upon the analysis, a determination is made as to whether a fault has occurred in the network and/or where the occurrence occurred.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: November 25, 2014
    Assignee: Howard University
    Inventor: Charles J Kim
  • Publication number: 20140247056
    Abstract: A series summation-calibrating device based on a semi-insulating voltage transformer includes a symmetrical high voltage test power supply, a three-port serial voltage transformer, a semi-insulating voltage transformer and an error measuring apparatus. The present invention is characterized by: a complete set of equipment for measuring the traceability of power frequency voltage ratio can be manufactured; calibrating the line according to the serial addition based on the semi-insulating voltage transformer; measuring the relative error between the three-port serial voltage transformer and the semi-insulating voltage transformer; and mathematically processing the measuring result to obtain the voltage coefficient curve of the semi-insulating voltage transformer error.
    Type: Application
    Filed: August 30, 2011
    Publication date: September 4, 2014
    Applicant: CHINA ELECTRIC POWER RESEARCH INSTITUTE
    Inventors: Feng Zhou, Min Lei, Min Li, Shuhan Zhang, Yueren Wang
  • Patent number: 8797045
    Abstract: A device for determining partial discharge in an insulation system of a rotating electrical machine with low capacitance decoupling has a coupler as a high pass and an adapter device connected or connectable to the coupler. The adapter device has a frequency separating filter for dividing a decoupled signal provided by the coupler into a high frequency signal and a low frequency signal. A mixer is provided for the high frequency signal and the low frequency signal for converting the high frequency signal. An output is provided where the converted high frequency signal is tapped for evaluation by an evaluation device connectable to the adapter device.
    Type: Grant
    Filed: March 25, 2011
    Date of Patent: August 5, 2014
    Assignee: Doble Lemke GmbH
    Inventors: Hendrik Elze, Stefan Kornhuber
  • Patent number: 8736277
    Abstract: Systems, methods and devices directed to transformers are disclosed. One transformer system includes a set of transformer cells and a controller. The set of transformer cells is coupled in series to form a series coupling, where each transformer cell includes at least one first coil and at least one second coil. The second coil is configured to receive electrical energy from the first coil through magnetic interaction. The controller is configured to modify electrical aspects at ends of the series coupling by independently driving the transformer cells such that at least one of the transformer cells is driven differently from at least one other transformer cell in the set.
    Type: Grant
    Filed: February 9, 2012
    Date of Patent: May 27, 2014
    Assignee: International Business Machines Corporation
    Inventors: Dennis G. Manzer, Bucknell C. Webb
  • Publication number: 20140118003
    Abstract: This invention publishes a fault diagnosis and location system for transformer core looseness, consists of vibration sensors, data collection and computer. It is of power transformer fault intelligent diagnosis technology technical field. Fault diagnosis and location method uses three vibration sensors positioned on the top of transformer tank, to obtain vibration signal, uses signal processing to analyze the signal, and obtains fault characteristics of the transformer core looseness. The characteristics respectively are 50 Hz, 150 Hz and 300 Hz frequency components, in which 300 Hz is main feature. When they reach a certain value at one position, it suggests that transformer core looseness near this position. By the comparison of differences among signals of three positions, fault location can be done. This invention manifests fault characteristics accurately and detects core looseness efficiently.
    Type: Application
    Filed: July 19, 2012
    Publication date: May 1, 2014
    Applicant: JIANGSU ELECTRIC POWER COMPANY
    Inventors: Kai Chen, Chunning Wang, Hongzhong Ma, Kai Li, Yiming Wu, Ying Zhang, Hongtao Liu, Peng Gao, Taotao Chen
  • Publication number: 20140049262
    Abstract: A transformer core apparatus includes a body of highly magnetically permeable material, a permanent magnet arranged in a safe state position for saturating the body with a permanent magnetic field, and means for removing the permanent magnetic field from the body.
    Type: Application
    Filed: August 16, 2012
    Publication date: February 20, 2014
    Inventor: Steven Murphy
  • Patent number: 8604805
    Abstract: The invention provides a property monitoring apparatus comprising a test current output circuit capable of varying an output current, a test current value computing means for computing a current value of a test current output from the test current output circuit, a test current control means for performing feedback control of the test current value computed via the test current value computing means to a target value, a measurement current detection circuit for measuring an output current value of the current transformer or the voltage transformer when the test current controlled to the target value via the test current control means is supplied, for storing a relationship between the output current value of the current transformer or the voltage transformer and the test current value for each target value by varying the target value of the test current via a predetermined pattern, and computing a correction coefficient for correcting a property of the current transformer or the voltage transformer based on t
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: December 10, 2013
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kouji Satou, Toshiko Kimura, Tetsunori Watanabe
  • Patent number: 8598742
    Abstract: A server and method detects a power transformer. The server reads power transformer data from a data converter and determines if work state of a power transformer needs to be changed from based on the power transformer data. An alert message is generated by the server and sent to an alarm computer in response to a determination that the work state of the power transformer needs to be changed. The server saves the power transformer data into a database system.
    Type: Grant
    Filed: December 12, 2010
    Date of Patent: December 3, 2013
    Assignees: GDS Software (ShenZhen) Co., Ltd, Hon Hai Precision Industry Co., Ltd.
    Inventors: Chi-Chih Wang, Bing-Yu He, Zhong-Gen Zhan, Wei Xiong
  • Patent number: 8587324
    Abstract: An apparatus for testing a high-voltage equipment transformer or inductor has a filter transformer having a primary side connectable to line and a secondary side and a grounded electrostatic shield between the primary and secondary sides. A static frequency converter has a plurality of inputs connected to the filter-transformer outputs and a plurality of outputs. Respective capacitors each have one side connected to a respective one of the converter outputs and an opposite side connected star-fashion to a common ground. A matching transformer has a plurality of inputs connected to the capacitors and a plurality of outputs connectable to the transformer or inductor to be tested.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: November 19, 2013
    Assignee: Maschinenfabrik Reinhausen GmbH
    Inventors: Rene Annowsky, Andreas Thiede
  • Publication number: 20130285671
    Abstract: A protective system far a power transformer having a neutral line connected to ground where large currents can flow in the neutral line due to electro-magnetic disturbances. The system includes circuitry for: (a) sensing the current level in the neutral line and whether it exceeds a predetermined threshold for a predetermined period; and (b) sensing and processing the harmonic content of the load current and determining the existence of certain relationships of the “even” and “odd” harmonics. Signals, including alarms, indicative of excessive conditions are produced. The system may also include circuitry for sensing the load current level and generating a signal alarm if the load level is above a giver) value when the harmonics and the DC current have values in excess of certain predetermined values.
    Type: Application
    Filed: January 8, 2013
    Publication date: October 31, 2013
    Inventors: GARY R. HOFFMAN, EDWARD S. KWON, HONG CAI
  • Patent number: 8552737
    Abstract: A high-voltage transformer for providing an alternating voltage in the kV range, comprising at least one secondary winding wound on a coil carrying body surrounding a transformer core, and an insulation housing encapsulating the secondary winding is provided to electrically insulate the secondary winding. Said insulation housing is walled by the coil carrying body carrying the secondary winding and by an enveloping body made of plastic and enveloping the secondary winding so that an annular gap is formed, wherein the annular gap between the secondary winding and the enveloping body is filled with an insulating fluid. The annular gap has a gap width of less than or equal to 20 mm viewed in the cross-section, and the enveloping body has a wall thickness of less than or equal to 20 mm, wherein the plastic is polypropylene, and a separate expansion volume is not provided for the insulating fluid.
    Type: Grant
    Filed: March 3, 2011
    Date of Patent: October 8, 2013
    Assignee: B2 Electronic GmbH
    Inventors: Rudolf Blank, Stefan Baldauf
  • Patent number: 8531188
    Abstract: An improved internturn short circuit detection device of transformer via differential voltage comprises a single-phase transformer (TM). The single-phase transformer (TM) comprises a high-voltage coil (K) and a low-voltage coil (N). A voltage transformer (PT) is positioned at the high voltage side of the single-phase transformer (TM). Two branches of a tap (K1) of the high-voltage coil (K) are connected with the input of a first converter (Q?), and a first voltage (U1?) is obtained. The secondary side of the voltage transformer (PT) is connected with the input of a second converter (Q), and a second voltage (U1) is obtained, and the first voltage (U1?) and the second voltage (U1) are compared, and when the voltage difference is above a predetermined primary threshold value, an interturn short circuit failure of the primary side is determined.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: September 10, 2013
    Assignee: Zhejiang Guangtian Transformer Co., Ltd.
    Inventor: Xiping Zhao