Counter Electromotive Force Patents (Class 361/4)
  • Patent number: 10468207
    Abstract: An arc extinguishing power device driving apparatus and an arc extinguishing apparatus of the present disclosure belong to the electrical field, and are particularly an arc extinguishing power device driving apparatus applicable to an electronic arc extinguishing apparatus for driving a power device. The power device that needs to be driven is connected in parallel to a mechanical switch that requires arc extinguishing, and includes a first voltage detection switch. An input end of the first voltage detection switch is connected to two ends of the power device. The first voltage detection switch is connected in series in a driving loop of the power device. The first voltage detection switch is turned on when detecting that there is a potential difference between the two ends of the power device. A driving signal is transferred to the power device by using the first voltage detection switch, to drive the power device to be turned on.
    Type: Grant
    Filed: January 20, 2017
    Date of Patent: November 5, 2019
    Inventor: Qiaoshi Guo
  • Patent number: 10236675
    Abstract: An electric power delivery system may be protected upon occurrence of a fault condition by the systems and methods disclosed herein by detecting the fault condition and signaling a protective action before the overcurrent condition reaches the protective equipment. The protective action may be an opening of a circuit breaker or engagement of a fault current limiter. The overcurrent condition may be a non-steady-state condition. The fault may be detected using traveling wave or incremental quantity techniques.
    Type: Grant
    Filed: July 7, 2017
    Date of Patent: March 19, 2019
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventors: Edmund O. Schweitzer, III, Bogdan Z. Kasztenny, David E. Whitehead
  • Patent number: 9899159
    Abstract: The present invention relates to an electric switch comprising a first switch assembly (1) with several electric breaker elements (2a, 2b, 2c) connected in series between two connection terminals (5, 6), and a second switch assembly (4) with a electric breaker element (3) connected in parallel to the first switch assembly (1). The second switch assembly (4) has less electrical resistance than the first switch assembly (1). The switch is configured so that the second switch assembly (4) closes in a delayed manner with respect to the closing of the first switch (1). Current interruption operations are performed with the first switch assembly (1) to facilitate arc quenching, whereas in permanent working of the switch, current flows through the low electrical resistance second breaker element (4) to reduce losses due to heating. The invention also relates to a method for controlling current flow.
    Type: Grant
    Filed: November 7, 2014
    Date of Patent: February 20, 2018
    Assignee: Gorlan Team, S.L.U.
    Inventor: Jose Oscar Andaluz Sorlí
  • Patent number: 9148011
    Abstract: An apparatus is arranged to break an electrical current. The apparatus includes: a mechanical switch leg including a first winding of a mutual inductor and a mechanical switch connected in series; a semiconductor switch leg including a second winding of the mutual inductor and a semiconductor switch connected in series; and an overvoltage protection circuit. The mechanical switch leg and the semiconductor switch leg are connected in parallel and a self inductance of the second winding is lower than a self inductance of the first winding. A corresponding DC circuit breaker and AC current limiter are also presented.
    Type: Grant
    Filed: August 27, 2012
    Date of Patent: September 29, 2015
    Assignee: ABB TECHNOLOGY LTD
    Inventors: Jesper Magnusson, Lars Liljestrand, Robert Saers
  • Publication number: 20140376132
    Abstract: An electrical circuit to interrupt a DC current includes a bypass switch and an AC high voltage breaker which includes interrupters that are rated for carrying a current having a value of the DC current for a period of time less than or equal to continuous duty. The first interrupter is electrically coupled in parallel with the bypass switch. A making switch causes a cancellation current to flow from an energy source through the second interrupter, and through the first interrupter, in addition to the DC current. The AC high voltage breaker is adapted to a DC service as the DC current in addition to the cancellation current causes an arc quench which allows the AC high voltage breaker to cause the interruption of the DC current in the electrical circuit. A method for interrupting a DC current flowing in an AC high voltage circuit breaker is also described.
    Type: Application
    Filed: September 8, 2014
    Publication date: December 25, 2014
    Inventors: William A. Carter, Scott C. Carter, Ilkka T. Pylkkanen
  • Patent number: 8803358
    Abstract: The present invention relates to an HVDC switchyard arranged to interconnect a first part of a DC grid with a second part of the DC grid. By means of the invention, a first part of the DC grid is connected to the busbars of the HVDC switchyard via a fast DC breaker, while further part(s) of the DC grid are connected to the busbars of the HVDC switchyard by means of switchyard DC breakers of lower breaking speed. By use of the inventive HVDC switchyard arrangement, the cost for the HVDC switchyard can be considerably reduced, while adequate protection can be provided. In one embodiment, the fast DC breaker is an HVDC station DC breaker forming part of an HVDC station. In another embodiment, the fast DC breaker is a switchyard DC breaker.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: August 12, 2014
    Assignee: ABB Technology AG
    Inventors: Jürgen Häfner, Björn Jacobson, Tomas Jonsson, Kerstin Lindén, Bertil Berggren
  • Publication number: 20140146422
    Abstract: In a gas circuit breaker with a parallel capacitor, an interrupting unit is provided inside a sealed vessel filled with an insulating gas; the interrupting unit includes fixed and movable parts. A high-voltage conductor is coupled to the movable part, and an interrupting-unit side insulating rod for moving the movable part is linked with a mover as part of an electric actuator inside an operation device case. A capacitor is electrically coupled to the interrupting unit in parallel inside the sealed vessel. A movable contact is electrically coupled to the capacitor, and the movable contact is linked with a capacitor-side insulating rod. The interrupting-unit side insulating rod or mover has an engaging part inside the case, the capacitor-side insulating rod has a retaining part located on a side of the engaging part, and the retaining part is linked with the sealed vessel by use of a closing-spring.
    Type: Application
    Filed: November 27, 2013
    Publication date: May 29, 2014
    Applicant: HITACHI, LTD.
    Inventors: Daisuke NOMURA, Masanori TSUKUSHI
  • Patent number: 8655500
    Abstract: A system and method that analyzes at least one aspect of the power grid for demand response in order to reduce feeder circuit losses is provided. The system and method may use a demand response model to select one or more factors for the demand response, such as selecting a subset of customers for demand response from a larger pool of available demand response customers. The demand response model may include a grid structure component, such as an indication of the particular customer's position in the grid, and a dynamic operation component, such as a real-time measurement of current in the feeder circuit. By using the demand response model, feeder circuit losses may thereby reduced.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: February 18, 2014
    Assignee: Accenture Global Services Limited
    Inventor: Jeffrey D. Taft
  • 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: 8467155
    Abstract: The invention provides a switching device having a contact protection circuit for arcing suppression. The switching device comprises a main relay for interrupting a load path and a dual coil auxiliary having a high resistance coil and a low resistance coil that operate the switching of an auxiliary contact. The auxiliary contact is connected in series with a PTC device and the low resistance coil of the auxiliary relay in a series arrangement. The series arrangement is connected in parallel to the main contact. When the main relay opens, the auxiliary contact is maintained closed during a given time interval due to the magnetic flux generated by the low resistance coil. The given time interval depends on the transition of the PTC device to trip state. In another configuration, the dual coil relay is substituted by two auxiliary relays.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: June 18, 2013
    Assignee: Tyco Electronics AMP GmbH
    Inventors: Matthias Kroeker, Joerg Einhorn, Gilles Gozlan
  • Patent number: 8270128
    Abstract: A commutation type DC breaker comprising a main switch inserted in series into a main circuit for connecting a DC source and a load, a commutation capacitor, a reactor, and a commutation switch for supplying charges stored in the commutation capacitor to the main switch in an opposite direction to a main circuit current, producing a current zero point, thereby breaking the main switch, characterized in that the commutation capacitor, the reactor, and the commutation switch which are composed a commutation circuit and a control circuit for controlling the turning on or off of the main switch and the commutation switch are loaded on a frame with the main switch loaded.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: September 18, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Noriaki Munakata, Masato Suzuki, Yoshihiko Matsuda, Naoki Kawamura, Manaba Takamoto
  • Patent number: 8150557
    Abstract: A system and method that analyzes at least one aspect of the power grid for demand response in order to reduce feeder circuit losses is provided. The system and method may use a demand response model to select one or more factors for the demand response, such as selecting a subset of customers for demand response from a larger pool of available demand response customers. The demand response model may include a grid structure component, such as an indication of the particular customer's position in the grid, and a dynamic operation component, such as a real-time measurement of current in the feeder circuit. By using the demand response model, feeder circuit losses may thereby reduced.
    Type: Grant
    Filed: June 8, 2010
    Date of Patent: April 3, 2012
    Assignee: Accenture Global Services Limited
    Inventor: Jeffrey D. Taft
  • Patent number: 8134820
    Abstract: A contactor control circuit is disclosed for controlling a contactor connecting an alternating current electrical power source to a load. The contactor control circuit comprises a switching circuit connected in series with the inductor for controlling the conduction of the contactor. The control circuit actuates conduction of current through the inductor for energizing the contactor to connect the alternating current electrical power source to the load. The invention is also incorporated into a circuit for switching a first and a second alternating current electrical power source to a load.
    Type: Grant
    Filed: September 8, 2008
    Date of Patent: March 13, 2012
    Inventors: James E. Riccio, Frank S. Brugner
  • Patent number: 7970650
    Abstract: A POS device includes a rotation shaft vertically fixed, a rotary plate provided so as to be rotatable about the rotation shaft, a rotating portion placed on the rotary plate and having at least a barcode scanner and a receipt printer, and a display device for clerk and a display device for customer both provided at the top end of the rotation shaft.
    Type: Grant
    Filed: January 29, 2009
    Date of Patent: June 28, 2011
    Assignee: NEC Infrontia Corporation
    Inventor: Mitsuhiro Tokorotani
  • Patent number: 7875822
    Abstract: A multiphase current interrupter is provided for interrupting a phase current between two contacts in an electrical phase. The current interrupter includes a first ablative chamber disposed around contacts for a first electrical phase. The first chamber has an ablative material thereon that causes a shock wave when an electrical arc is generated in an arc zone for the first electrical phase during a separation of the contacts therein. The current interrupter further includes at least a second ablative chamber disposed around contacts for at least a second electrical phase. The second chamber has an ablative material thereon that causes a shock wave when an electrical arc is generated in an arc zone for the second electrical phase during a separation of the contacts therein. An interconnecting structure provides fluid communication between the first ablative chamber and the second ablative chamber. The interconnecting structure is adapted to dissipate a shock wave generated in any of the ablative chambers.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: January 25, 2011
    Assignee: General Electric Company
    Inventors: Thangavelu Asokan, Sunil Srinivasa Murthy, Kunal Ravindra Goray, Nimish Kumar, Adnan Kutubuddin Bohori
  • Publication number: 20100208392
    Abstract: A commutation type DC breaker comprising a main switch inserted in series into a main circuit for connecting a DC source and a load, a commutation capacitor, a reactor, and a commutation switch for supplying charges stored in the commutation capacitor to the main switch in an opposite direction to a main circuit current, producing a current zero point, thereby breaking the main switch, characterized in that the commutation capacitor, the reactor, and the commutation switch which are composed a commutation circuit and a control circuit for controlling the turning on or off of the main switch and the commutation switch are loaded on a frame with the main switch loaded.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 19, 2010
    Applicant: HITACHI, LTD.
    Inventors: Noriaki MUNAKATA, Masato SUZUKI, Yoshihiko MATSUDA, Naoki KAWAMURA, Manabu TAKAMOTO
  • Patent number: 7778738
    Abstract: A system and method that analyzes at least one aspect of the power grid for demand response in order to reduce feeder circuit losses is provided. The system and method may use a demand response model to select one or more factors for the demand response, such as selecting a subset of customers for demand response from a larger pool of available demand response customers. The demand response model may include a grid structure component, such as an indication of the particular customer's position in the grid and a dynamic operation component, such as a real-time measurement of current in the feeder circuit. By using the demand response model, feeder circuit losses may thereby reduced.
    Type: Grant
    Filed: February 11, 2009
    Date of Patent: August 17, 2010
    Assignee: Accenture Global Services GmbH
    Inventor: Jeffrey D. Taft
  • Patent number: 7660083
    Abstract: An electromechanical/solid-state AC relay has an electromechanical winding coil that moves an armature to force mechanical contacts to open or close. Electrical arcing across the mechanical contacts that occur as the contacts are opening or closing can damage and severely reduce the lifetime of the relay. Contact arcing is prevented by pulsing a triac on for a short period of time just before and after the mechanical contacts make or break contact. The triac limits the voltage difference across the mechanical contacts to less than one volt to prevent arcing. The triac is turned off after the mechanical contacts finish moving, reducing the heating and average power through the triac. A zero-sampling circuit that detects when the AC input voltage switches across 0 volts and activates a control integrated circuit to switch on the triac during zero-crossings to minimize power surges.
    Type: Grant
    Filed: August 6, 2007
    Date of Patent: February 9, 2010
    Assignee: Pericom Technology Inc.
    Inventors: Li Yao, Shu Peng Chen, Yong Wei
  • Patent number: 7542250
    Abstract: A motor starter is provided. The motor starter includes micro-electromechanical system switching circuitry. The system may further include solid state switching circuitry coupled in a parallel circuit with the electromechanical switching circuitry, and a controller coupled to the electromechanical switching circuitry and the solid state switching circuitry. The controller may be configured to perform selective switching of a load current from a motor connected to the motor starter. The switching may be performed between the electromechanical switching circuitry and the solid state switching circuitry in response to a load current condition appropriate to an operational capability of a respective one of the switching circuitries.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: June 2, 2009
    Assignee: General Electric Company
    Inventors: William James Premerlani, Fengfeng Tao, Joshua Isaac Wright, Kanakasabapathi Subramanian, John Norton Park, Robert Joseph Caggiano, David James Lesslie, Brent Charles Kumfer, Charles Stephan Pitzen, Kathleen Ann O'Brien, Edward Keith Howell
  • Patent number: 6687100
    Abstract: A method of rapidly dissipating energy from a contactor controlled by a switching device, the steps comprising: operably connecting a metal oxide varistor to the switching device; interrupting electrical current to the contactor; absorbing energy from the contactor; and, limiting the amount of voltage across the switching device.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: February 3, 2004
    Assignee: Square D Company
    Inventors: Julius Isaiah Rice, Roger Alan Plemmons
  • Patent number: 6466420
    Abstract: A high voltage electrical disconnector that has a moving contact that moves at high speed comprises a moving first contact which is mounted to move along an axial direction relative to a fixed second contact, and which co-operates therewith to establish an electrical connection, and a rod extending along said axial direction and which is driven to move the first contact relative to the second contact. The first contact is a hollow tube in which there slides a piston mounted on the rod. A first spring is interposed between the moving contact and a first end of the piston, and a second spring is interposed between moving contact and a second end of the piston.
    Type: Grant
    Filed: May 16, 2000
    Date of Patent: October 15, 2002
    Assignee: Alstom
    Inventors: Olivier Chuniaud, Henri Jouard, Jean Marmonier, Bernard Regnier
  • Publication number: 20010021090
    Abstract: An electrical circuit interrupter includes a primary or normal current carrying path and a transient or alternative current carrying path. The normal current carrying path is established by a movable spanner extending between stationary contacts during normal operation. The transient current carrying path includes at least one variable resistance element which transitions from a lower resistance to a higher resistance during interruption. The transient current carrying path forms an open circuit in parallel with the normal current carrying path during normal operation. Upon interruption, the transient current carrying path is favored for the fault current, completely interrupting the normal current carrying path. The variable resistance elements increase their resistivity during this phase of operation to aid in providing high levels of back-EMF for complete interruption of fault current through the device and limitation of let-through energy.
    Type: Application
    Filed: December 22, 1998
    Publication date: September 13, 2001
    Inventors: DAVID J. BENARD, PAUL T. NOLDEN, EDWARD A. MALLONEN, MARK A. CLAYTON
  • Publication number: 20010015879
    Abstract: A method for interrupting current is provided wherein substantially all current is conveyed through a normal current carrying path in a circuit interrupter. A movable element is displaced for interruption of the current, and a balance is struck between the normal current carrying path and a parallel alternative or transient current carrying path. The transient current carrying path includes at least one variable or controllable resistance element. The transient current carrying path presents a substantially open circuit during normal operation. The variable resistance elements have a lower resistance during initial phases of circuit interruption, favoring transition of all current from the normal current carrying path to the transient path. Thereafter, the variable resistance elements increase in resistivity, producing additional back-EMF to drive the fault current to a zero level and to limit let-through energy.
    Type: Application
    Filed: December 22, 1998
    Publication date: August 23, 2001
    Inventors: DAVID J. BENARD, PAUL T. NOLDEN, EDWARD A. MALLONEN, MARK A. CLAYTON
  • Patent number: 6075684
    Abstract: In the direct current circuit interruption arrangements disclosed in the specification, a solid state circuit interrupter interrupts the connection in a circuit path between a power source and a load. The stored energy in the circuit is dissipated in a resistive commutation circuit by using controllable power semiconductors such as Insulated Gate Bipolar Transistors to increase resistance between the terminals of the circuit interruption arrangement. An in-line power semiconductor switch acts as the circuit disconnecting device and is shunted by a resistive commutation circuit consisting of a plurality of solid state commutation switches and resistors in various configurations which act to dissipate the energy. In one embodiment the solid state switches in the commutation circuit are connected to a common circuit interrupter terminal and to a resistor through a series of taps on the resistor and the resistor is connected to the other circuit interrupter terminal.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: June 13, 2000
    Assignee: Electric Boat Corporation
    Inventors: Greg A. Duba, Edgar S. Thaxton, John Walter
  • Patent number: 5854729
    Abstract: A device/method for actively interrupting fault current in an ac or dc power system before the fault current is capable of growing to peak magnitude or steady state condition, respectively, is presented. In an ac implementation, a commutating capacitance of desired polarity from one of two commutating circuits is coupled across a circuit interrupter comprising a pair of separable contacts. The circuit interrupter operates to open circuit the power system upon reaching zero current therethrough. The commutating capacitance of appropriate polarity actively drives the fault current to zero before the fault current reach peak magnitude, thereby allowing the circuit interrupter to open circuit the power system before the fault current's natural current zero. In dc implementation, the commutating capacitance is connected to dissipate a fault current while the system is in transient state, thereby protecting the power system from full steady state fault current condition.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: December 29, 1998
    Assignee: Utility Systems Technologies, Inc.
    Inventors: Robert C. Degeneff, Moises R. Gutierrez, Mietek T. Glinkowski
  • Patent number: 5703743
    Abstract: The arc suppression circuit includes an insulated gate bipolar junction transistor (IGBT) connected across the electrical switch contacts to be protected. When the contacts open, the combination of added Miller capacitance and the gate-to-emitter capacitance of the IGBT results in the IGBT turning on. The IGBT is quickly turned off thereafter by a second transistor, which turns on as the voltage across the suppression circuit rises following turn-on of the IGBT. The turning on of the second transistor results in the first power transistor quickly and abruptly turning off so that relatively little of the load energy is dissipated in the power transistor.
    Type: Grant
    Filed: April 29, 1996
    Date of Patent: December 30, 1997
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventor: Tony J. Lee
  • Patent number: 5517378
    Abstract: A high power d.c. breaker for connection into a d.c. carrying high-voltage line (L), has two normally closed and electrically series-connected mechanical breaks (BSI, BSII) adapted to be traversed by the line current (I) and to be opened for breaking the current. A capacitor (CB) is connected in parallel with the series connection of the breaks. A semiconductor member (HO) is connected in parallel with one of the breaks (BSI). Upon opening the breaks, a control member (SO) controls the semiconductor member such that a zero crossing of the current through the second break (BSII) is obtained, whereby the line current (I) is commutated over to the capacitor. (FIG.
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: May 14, 1996
    Assignee: ASEA Brown Boveri AB
    Inventors: Gunnar Asplund, Victor Lescale, Carl E. Solver
  • Patent number: 5502609
    Abstract: A contactor control system for a DC electric power system for reducing contactor tip contamination from dry-switching includes a first switch connected in circuit between a power source and a controller for enabling the controller upon closure of the first switch. A PTC resistor is connected between the first switch and a filter capacitor whereby charging current is supplied to the capacitor upon closure of the first switch. A solid-state switch is connected in series circuit with an electromagnetic actuator of a contactor having power contact tips in circuit between the power source and a load. The series combination of the actuator and solid-state switch is connected in parallel circuit with the filter capacitor.
    Type: Grant
    Filed: December 8, 1994
    Date of Patent: March 26, 1996
    Assignee: General Electric Company
    Inventors: Sherrill G. Thomas, Larry G. Ball
  • Patent number: 5452170
    Abstract: A commutation type DC breaker having a commutation circuit electrically connected in parallel to a main contact. The main contact is connected between a DC power supply and a load. The commutation circuit is a series circuit of a commutation capacitor, a reactor and a commutation switch, with an energy absorption device electrically connected in parallel to the main contact. A switch or a breaker for preventing the flow of commutation current from the commutation circuit to the load in a non-load opening mode is connected between an electrical connection point (P), of the main contact and the commutation circuit, and the load and is opened substantially simultaneously with the opening of the main contact, or before the closure of the commutation switch. In this manner, the safety on the load in the non-load opening mode is enhanced.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: September 19, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Ohde, Shigetoshi Ouchi, Haruo Honda, Toru Yoshida, Tutomu Kanno, Yukio Kugoh
  • Patent number: 5402297
    Abstract: A commutating type DC circuit breaker arrangement comprising: a vacuum circuit breaker having a movable electrode and stationary electrode; a series circuit of a capacitor, a saturation reactor and a commutating switch which is connected in parallel with the vacuum circuit breaker; and an electrical relay for detecting a predetermined electrode open position at which a sufficient insulating distance between the movable electrode and the stationary electrode is maintained via movement of a predetermined position on an actuating rod for the movable electrode and for closing the commutating switch in response to the detection of the predetermined electrode open position.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: March 28, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Shigetoshi Ouchi, Haruo Honda, Toru Yoshida, Yukio Kugoh, Fumihisa Ichikawa, Tutomu Kanno, Takashi Ichinose, Hideaki Tsuda
  • Patent number: 5335139
    Abstract: A multilayer ceramic chip capacitor includes alternately stacked dielectric layers and internal electrode layers. The dielectric layers contain barium titanate as a major component and magnesium oxide, manganese oxide, barium oxide and/or calcium oxide, silicon oxide and optionally, yttrium oxide as minor components in such a proportion that there are present 0.1-3 mol of MgO, 0.05-1.0 mol of MnO, 2-12 mol of BaO+CaO, 2-12 mol of SiO.sub.2 and up to 1 mol of Y.sub.2 O.sub.3 per 100 mol of BaTiO.sub.3. The capacitor satisfies the standard temperature dependence of capacitance and shows a minimized change of capacitance with time under an applied DC electric field and a long insulation resistance life. Where the dielectric layers contain 0.1-3 mol of MgO, 1-5 mol of Y.sub.2 O.sub.3, 2-12 mol of BaO+CaO, and 2-12 mol of SiO.sub.2 per 100 mol of BaTiO.sub.3, the capacitor shows improved DC bias performance.
    Type: Grant
    Filed: July 13, 1993
    Date of Patent: August 2, 1994
    Assignee: TDK Corporation
    Inventors: Takeshi Nomura, Yukie Nakano, Akira Satoh, Tomohiro Arashi
  • Patent number: 5214557
    Abstract: A vacuum circuit breaker particularly suitable for use in an electric motor vehicle. The circuit breaker includes a vacuum interrupter to which a voltage is applied, the series combination of a capacitor and a switch which are connected in parallel with the vacuum interrupter, a provision for charging the capacitor with a voltage opposite the voltage applied to the vacuum interrupter, and a resistance connected in parallel with the vacuum interrupter. The vacuum interrupter, the resistance, and the series combination of the capacitor and switch form oscillation circuit having an oscillation frequency at least 2 KHz and an inductance of at least 1 .mu.H, with a commutating current of at least 5000 A for consuming energy stored in the circuit.
    Type: Grant
    Filed: July 31, 1990
    Date of Patent: May 25, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuyoshi Hasegawa, Takashi Tsuboi, Hiroyuki Akiyama, Tadashi Kamada, Taro Uchii
  • Patent number: 5210674
    Abstract: A superconducting coil protective system comprises a quenching detector (QD) for detecting occurrence of a quenching in a superconducting coil (L) and generating a quenching signal indicative of the occurrence of the quenching. In response to the quenching signal, a voltage controller (VC) reduces an output voltage from a power source (PS) to zero or to a negative polarity. A current interrupter (CI) including a circuit breaker (CB) or a fuse (F) is connected in parallel to the superconducting coil (L) for allowing a first commutation of a current from the superconducting coil (L) to the current interrupter (CI) upon the reduction of the output voltage from the power source (PS). The system also comprises a protective resistor (RD) connected in parallel to the current interrupter (CI) for allowing a second commutation of the first-commutated current thereto upon the opening of the current interrupter (CI), whereby energy of the second-commutated current is dissipated in the protective resistor.
    Type: Grant
    Filed: May 29, 1991
    Date of Patent: May 11, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Satarou Yamaguchi, Tadanori Tsukamoto
  • Patent number: 4805062
    Abstract: A DC circuit breaker and a method of commutation during a commutation capacitor capable of being directly charged from a main DC line are disclosed. A breaker unit is inserted in a main DC line and is connected through a first switch in parallel to a series circuit including a commutation capacitor and a reactor. At end of the commutation capacitor is connected to the power side of the main DC line, and the other end thereof to the negative bus of the DC line through a charge capacitor. A series circuit including a magnetic repulsive coil and a second switch is connected in parallel to the commutation capacitor, which is directly charged from the power side of the main DC line. When the breaker unit starts to open, the second switch is turned on so that the polarity of the charged commutation capacitor is reversed to permit a discharged current to flow in the breaker unit in the opposite direction, while at the same time starting the opening of the breaker unit.
    Type: Grant
    Filed: October 14, 1987
    Date of Patent: February 14, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuji Shirouzu, Masatoshi Morita, Satoshi Mizuno
  • Patent number: 4740858
    Abstract: A zero-current arc-suppression circuit breaker arrangement having a series circuit including a capacitor power source previously charged and a switch connected in parallel with a series circuit formed of a circuit breaker and a diode. Upon operation, the capacitor power source provides a reverse current for reducing the current flowing to the circuit breaker to a zero-current level and the diode maintains the circuit breaker current at the zero-current level for a predetermined period of time. When the contacts of the circuit breaker are separated during this period, no arc plasma is generated to protect the circuit breaker from damage.
    Type: Grant
    Filed: August 5, 1986
    Date of Patent: April 26, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Satarou Yamaguchi, Hirohide Hirayama
  • Patent number: 4618905
    Abstract: A line voltage charging type DC circuit breaker for use in DC transmission, having a series circuit connected in parallel with a commutation breaker, the series circuit being constituted by a capacitor to be charged by a line voltage, a reactor, and a circuit-closing means connected in series with each other, the DC circuit breaker comprising a circuit for charging the capacitor, the charging circuit including a current direction restricting circuit for restricting a current flowing through the restricting circuit only in one direction and a reverse control circuit for controlling the current direction restricting circuit to reverse the direction of a current for charging the capacitor in accordance with the power flow reversal control of the DC transmission.
    Type: Grant
    Filed: September 21, 1984
    Date of Patent: October 21, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Shunji Tokuyama, Koji Suzuki, Keiji Arimatsu
  • Patent number: 4578730
    Abstract: There is disclosed a high-voltage DC circuit breaker apparatus with reverse current insertion system by line voltage charge, which comprises a commutation switch, a series circuit of a capacitor, a reactor and a switch connected in parallel with the commutation switch, a resistor connected so as to charge the capacitor by a line voltage. The charging time constant of the capacitor determined by the capacity of the capacitor and the resistor is used as a reference in a manner so that the rise time constant of the line voltage is smaller than the charging time constant of the capacitor, and the rise time constant of the line current is larger than the charging time constant of the capacitor, thereby interrupting the fault current without fail.
    Type: Grant
    Filed: October 12, 1983
    Date of Patent: March 25, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Shunji Tokuyama, Kooji Suzuki, Kunio Hirasawa, Yoshio Yoshioka, Keiji Arimatsu
  • Patent number: 4544978
    Abstract: A circuit for the arcless de-energization of a direct current load receiving direct current from a rectified alternating current source. The circuit includes a means for rectifying alternating current from an alternating current source to provide direct current to the direct current load. The means for rectifying has a current flow controller, such as a silicon controlled rectifier, connected with each phase of the alternating current source. The circuit also has means for de-energizing the then conducting current flow controller in said means for rectifying, the means for de-energizing having a current flow controller, such as a silicon controlled rectifier. The circuit further includes a voltage detection device for detecting a predetermined voltage drop in the circuit; and a time delay device for regulating the activation of the means for de-energizing.
    Type: Grant
    Filed: March 30, 1984
    Date of Patent: October 1, 1985
    Assignee: Consolidation Coal Company
    Inventor: David J. Podobinski
  • Patent number: 4449162
    Abstract: A drive circuit for an electromagnetic device includes an inductor which can be connected across a pair of supply lines by way of a first switch. Energy is stored in the core of the inductor which can be released into the device to cause rapid operation thereof by opening the first switch and closing a second switch. When the energy in the inductor has been dissipated a low level of current is allowed to flow into the device by way of the inductor from the supply lines and this flow of current can be maintained by means of a diode when the first switch is closed to re-energize the inductor.
    Type: Grant
    Filed: November 4, 1981
    Date of Patent: May 15, 1984
    Assignee: Lucas Industries Limited
    Inventor: Keith Heppenstall
  • Patent number: 4442469
    Abstract: A DC circuit breaker apparatus comprises a first interrupter and a second interrupter connected in series. A first capacitor and a discharge gap are respectively connected in parallel with the first and second interrupters. An impedance element is connected between a first junction between the first capacitor and the discharge gap and a second function between the first and second interrupter, and a second capacitor is connected in parallel with the second interrupter.
    Type: Grant
    Filed: August 18, 1982
    Date of Patent: April 10, 1984
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Satoru Yanabu, Tohoru Tamagawa, Takumi Funahashi
  • Patent number: 4356525
    Abstract: A method and circuit for minimizing DC current offset generated by the voltage-integrating property of an inductive load. First, second and third hybrid contactors connect first, second, and third output lines of an AC power source to first, second, and third input lines of an inductive load. Each hybrid contactor includes a pair of relay contacts in parallel with a semiconductor switching unit having two antiparallel-connected silicon-controlled-rectifiers. A latching circuit and several delay circuits are used to turn on and off the hybrid contactors; the timing of the turn-on points is controlled relative to a zero-crossing of a voltage from the AC power source such that minimal DC offset current occurs.
    Type: Grant
    Filed: January 5, 1981
    Date of Patent: October 26, 1982
    Assignee: General Electric Company
    Inventors: William P. Kornrumpf, Joseph L. Ciccone
  • Patent number: 4346420
    Abstract: A magnetoplasmadynamic switch adapted to be coupled in parallel with an ictive energy storage circuit carrying current through an initially closed circuit interrupter. The switch includes an electrode spaced by a gap from an arcjet source which is triggered by a capacitor. The capacitor is connected to the arcjet source by a closing switch so that a plasma jet is created between the source and the electrode. The voltage on the capacitor is chosen such that the arcjet source current will equal the current in the energy storage circuit at the time when the circuit interrupter has completely opened. The circuit interrupter is opened after the plasma jet is established between the source and the electrode, and the energy storage circuit current is conducted by the magnetoplasmadynamic switch until the dielectric strength of the circuit interrupter reaches a satisfactory level. Another switch is then closed providing a low impedance conduction path parallel to the arcjet source current.
    Type: Grant
    Filed: May 28, 1980
    Date of Patent: August 24, 1982
    Assignee: The United States of America as represented by the Secretry of the Navy
    Inventor: Peter J. Turchi
  • Patent number: 4319296
    Abstract: The invention provides a technique for interrupting current employing a plurality of series connected vacuum arcs in parallel with a resonating circuit. At least one of the series vacuum arcs is subjected to an oscillating transverse magnetic field which produces modulations in the arc voltage. The arc voltage modulations initiate oscillations in the parallel resonating circuit, producing current modulations in the series connected vacuum arcs. The current modulations rapidly extinguish the arcs, interrupting the current. Use of a plurality of series connected vacuum arcs improves the recovery voltage hold-off potential of the circuit.
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: March 9, 1982
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Clive W. Kimblin, Francis A. Holmes, Joachim V. R. Heberlein, Joseph G. Gorman, Paul G. Slade
  • Patent number: 4307428
    Abstract: A circuit breaker apparatus of high voltage direct currents is connected in series with an external circuit comprising an AC-DC converting device connected to an AC power supply and a DC reactor connected to the AC-DC converting device, and comprises a circuit breaker connected in series with the external circuit, a disconnecting switch connected to the circuit breaker, and a series circuit connected in parallel with the circuit breaker and constituted of a blocking capacitor and a primary winding in a transformer. A charge storage capacitor is connected to a secondary winding of the transformer through a starting switch and polarity changeover switch, and an AC power supply for charging is connected through a diode to the charge storage capacitor.
    Type: Grant
    Filed: August 28, 1979
    Date of Patent: December 22, 1981
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Satoru Yanabu, Toru Tamagawa, Susumu Nishiwaki
  • Patent number: 4305107
    Abstract: A DC interrupter unit as provided between a DC power source unit and a load unit. The DC interrupter unit includes a DC interrupter section having at least one interrupter to interrupt a DC current and a saturable reactor connected between the interrupter section and one terminal of the load unit. The interrupter unit further includes a series circuit having a resistor and capacitor in series, the series circuit being connected between the junction of the interrupter section and the saturable reactor and the other terminal of the load unit.
    Type: Grant
    Filed: August 16, 1979
    Date of Patent: December 8, 1981
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Minoru Murano, Satoru Yanabu, Tohru Tamagawa, Hisatoshi Ikeda
  • Patent number: 4300181
    Abstract: A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.
    Type: Grant
    Filed: November 28, 1979
    Date of Patent: November 10, 1981
    Assignee: General Electric Company
    Inventor: William J. Premerlani
  • Patent number: 4287436
    Abstract: An electrical circuit for driving an inductive load includes an output transistor of one conductivity type and a detector transistor of the other conductivity type. The output transistor has an emitter connected to a power source, a base to which an input signal is supplied, and a collector connected to one end of an inductive load. The detector transistor has an emitter connected to the collector of the output transistor, a base connected to the other end of the inductive load, and a collector connected to the base of the output transistor. When the output transistor is rendered nonconductive, high counter electromotive force is induced between both ends of the inductive load. Thereby the detector transistor turns on and the output transistor is rendered conductive again.
    Type: Grant
    Filed: May 18, 1979
    Date of Patent: September 1, 1981
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Hideharu Tezuka, Yuuichiro Furukawa
  • Patent number: 4249223
    Abstract: An arc quenching circuit senses initiation of an arc across the contacts of a contactor, commutates a capacitor discharge to the contacts that brings the contact voltage to zero for arc extinction and promptly recharges the capacitor to enable reoperation.
    Type: Grant
    Filed: December 1, 1978
    Date of Patent: February 3, 1981
    Assignee: Westinghouse Electric Corp.
    Inventors: Kenneth C. Shuey, Donal E. Baker, Charles L. Doughman
  • Patent number: 4216513
    Abstract: A capacitor and an inductance are connected in parallel with an interruptor disposed in a d-c circuit before the interruptor is mechanically opened. An oscillating current i.sub.o occurs in a circuit composed of the interruptor, the capacitor having a predetermined capacitance and the inductance having a predetermined amount of inductance when the interruptor is mechanically opened. The amplitude of the oscillating current i.sub.o is gradually increased and is superposed on a d-c current I. The interruptor breaks itself when the sum of the d-c current I and the oscillating current i.sub.o across the interruptor reaches zero.
    Type: Grant
    Filed: May 15, 1978
    Date of Patent: August 5, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Shunji Tokuyama, Hiroyuki Sugawara
  • Patent number: 4172268
    Abstract: A direct current circuit interrupting apparatus of the type wherein the arc of the circuit interruptor is extinguished by passing an oscillatory current from an oscillating circuit to the interrupted contacts via a switch means which is closed at the time when the circuit interruptor is opened includes a nonlinear resistor comprising a sintered mixture of metal oxides connected in parallel with the oscillating circuit.
    Type: Grant
    Filed: September 28, 1977
    Date of Patent: October 23, 1979
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Satoru Yanabu, Susumu Nishiwaki