Protective Circuit: (class 361/19) Patents (Class 505/850)
  • Patent number: 8988176
    Abstract: A superconducting magnet device is configured to include: a refrigerant circulation flowpath in which a refrigerant (R) circulates; a refrigerator for cooling vapor of the refrigerant (R) in the refrigerant circulation flowpath; a superconducting coil cooled by the circulating refrigerant (R); a protective resistor thermally contacting the superconducting coil and having an internal space (S); a high-boiling-point refrigerant supply section for supplying a high-boiling-point refrigerant having a higher boiling point than the refrigerant (R) and frozen by the refrigerant (R) to the internal space (S) in the protective resistor; and a vacuum insulating container for at least accommodating the refrigerant circulation flowpath, the superconducting coil, and the protective resistor.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: March 24, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Manabu Aoki, Ryuya Ando, Yukihiro Murata, Ryoji Nakagawa
  • Patent number: 8886267
    Abstract: A cryogenically-cooled HTS cable is configured to be included within a utility power grid having a maximum fault current that would occur in the absence of the cryogenically-cooled HTS cable. The cryogenically-cooled HTS cable includes a continuous liquid cryogen coolant path for circulating a liquid cryogen. A continuously flexible arrangement of HTS wires has an impedance characteristic that attenuates the maximum fault current by at least 10%. The continuously flexible arrangement of HTS wires is configured to allow the cryogenically-cooled HTS cable to operate, during the occurrence of a maximum fault condition, with a maximum temperature rise within the HTS wires that is low enough to prevent the formation of gas bubbles within the liquid cryogen.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: November 11, 2014
    Assignee: American Superconductor Corporation
    Inventors: Douglas C. Folts, James Maguire, Jie Yuan, Alexis P. Malozemoff
  • Patent number: 8862193
    Abstract: A connector assembly of a superconducting fault current limiter includes a first superconducting tape element, an electrical connector electrically coupled to the first superconducting element at a first region of the electrical conductor, and a second superconducting tape element electrically coupled to the electrical connector in a second region of the electrical connector. The electrical connector comprises a unitary structure. The first superconducting tape element, the electrical connector, and the second superconducting tape element comprise may comprise a layer.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: October 14, 2014
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventor: Kasegn D. Tekletsadik
  • Patent number: 8739396
    Abstract: Several embodiments of a novel technique for limiting transmission of fault current are disclosed. Current power distribution systems typically have an impedance, or reactor, on the output of the network equipment to limit current in the case of a fault condition. A low resistance switch, which changes its resistance in the presence of high current, is connected in parallel with this reactor. Thus, in normal operation, the current from the power generator bypasses the reactor, thereby minimizing power loss. However, in the presence of a fault, the resistance of the switch increases, forcing the current to pass through the reactor, thereby limiting the fault current.
    Type: Grant
    Filed: June 15, 2011
    Date of Patent: June 3, 2014
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventor: Paul J. Murphy
  • Patent number: 8532725
    Abstract: A method of controlling fault currents within a utility power grid is provided. The method may include coupling a superconducting electrical path between a first and a second node within the utility power grid and coupling a non-superconducting electrical path between the first and second nodes within the utility power grid. The superconducting electrical path and the non-superconducting electrical path may be electrically connected in parallel. The superconducting electrical path may have a lower series impedance, when operated below a critical current level, than the non-superconducting electrical path. The superconducting electrical path may have a higher series impedance, when operated at or above the critical current level, than the non-superconductor electrical path.
    Type: Grant
    Filed: January 25, 2010
    Date of Patent: September 10, 2013
    Assignee: American Superconductor Corporation
    Inventors: Douglas C. Folts, James Maguire, Jie Yuan, Alexis P. Malozemoff
  • Patent number: 8271062
    Abstract: A superconducting article and method of fabrication are provided. The superconducting article includes a superconducting structure, which includes a superconducting conductor and multiple discrete overlay regions of higher heat capacity than the superconducting conductor. The multiple discrete overlay regions are disposed along a length of the superconducting conductor, in thermal contact with the superconducting conductor, and positioned to define a heat modulation pattern along the length of the superconducting structure. The multiple discrete overlay regions create a temperature distribution favorable to transition of the superconducting structure under load from a normal resistive state to a superconductive state by facilitating formation of a continuous superconducting path along the length of the superconducting structure.
    Type: Grant
    Filed: April 27, 2009
    Date of Patent: September 18, 2012
    Assignee: Superpower, Inc.
    Inventor: Maxim Martchevskii
  • Patent number: 8252724
    Abstract: A fault current limiter, with a superconducting device (1; 21; 31; 41; 51; 61; 71; 72) comprising a sequence of superconducting elements (2a-2f), each with—a substrate (3a-3d), —a superconducting film (5a-5d), and —an intermediate layer (4a-4c) provided between the substrate and the superconducting film, wherein the superconducting films (5a-5d) of adjacent superconducting elements (2a-2f) of the sequence are electrically connected, in particular in series, is characterized in that the substrates (3a-3d) of the superconducting elements (2a-2d) are electrically conducting substrates (3a-3d), wherein the electrically conducting substrate (3a-3d) of each superconducting element (2a-2f) of the sequence is electrically insulated from each electrically conducting substrate (3a-3d) of those adjacent superconducting elements (2a-2f) within the sequence whose superconducting films (5a-5d) are electrically connected in series with the superconducting film (5a-5d) of said superconducting element (2a-2f), and that the in
    Type: Grant
    Filed: November 25, 2009
    Date of Patent: August 28, 2012
    Assignees: Areva T & D SAS, Bruker HTS GmbH
    Inventors: Francis James Mumford, Alexander Usoskin
  • Patent number: 8255024
    Abstract: Between adjacent windings of a bifilar coil made of an HTS strip conductor in a resistive superconductive current limiter device, a spacer is provided which is transparent for a coolant. The spacer includes an electrically insulating support tape for sufficiently massive spacer elements attached thereon. The spacer elements are spaced and made of a material having high thermal conductivity. The spaces between the spacer elements form cooling channels for the coolant.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: August 28, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hans-Peter Krämer, Wolfgang Schmidt
  • Patent number: 8252725
    Abstract: A fault current limiter, with a superconducting device (1; 21; 31; 41; 51; 61; 71; 72) comprising a sequence of superconducting elements (2a-2f), each with an electrically conducting substrate (3a-3d), a superconducting film (5a-5d), and an electrically insulating intermediate layer (4a-4c) provided between the substrate and the superconducting film, wherein the superconducting films (5a-5d) of adjacent superconducting elements (2a-2f) of the sequence are electrically connected, in particular in series, wherein the electrically conducting substrate (3a-3d) of each superconducting element (2a-2f) of the sequence is electrically insulated from each electrically conducting substrate (3a-3d) of those adjacent superconducting elements (2a-2f) within the sequence whose superconducting films (5a-5d) are electrically connected in series with the superconducting film (5a-5d) of said superconducting element (2a-2f).
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: August 28, 2012
    Assignees: Areva T & D SAS, Bruker HTS GmbH
    Inventors: Francis James Mumford, Alexander Usoskin
  • Patent number: 8247354
    Abstract: A fault current limiter and a method for the production thereof has a superconducting device (1; 21; 31; 41; 51; 61; 71; 72) comprising a sequence of superconducting elements (2a-2f), each with an electrically conducting substrate (3a-3d), a superconducting film (5a-5d) and an electrically insulating intermediate layer (4a-4c) provided between the substrate and the superconducting film. The superconducting films (5a-5d) of adjacent superconducting elements (2a-2f) of the sequence are electrically connected, in particular in series, wherein the electrically conducting substrate (3a-3d) of each superconducting element (2a-2f) of the sequence is electrically insulated from each electrically conducting substrate (3a-3d) of those adjacent superconducting elements (2a-2f) within the sequence whose superconducting films (5a-5d) are electrically connected in series with the superconducting film (5a-5d) of said superconducting element (2a-2f).
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: August 21, 2012
    Assignees: Areva T & D SAS, Bruker HTS GmbH
    Inventors: Francis James Mumford, Alexander Usoskin
  • Patent number: 8150486
    Abstract: The device has a quenchable superconductor (1), a first metallic member (2) electrically coupled with the quenchable superconductor (1), a second metallic member (3) electrically coupled to the first metallic member (2). The first metallic member (2) is thermally and electrically coupled with the quenchable superconductor (1) due to their direct surface contact. The superconducting device has a second metallic member (3) with a resistive element (4) and an electrical coupling (5) with the first metallic member (2). The resistive element (4) of the second metallic member (3) is thermally decoupled from the first metallic member (2). The first metallic member (2) has a substantially higher electrical resistance compared to the second metallic member (3).
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: April 3, 2012
    Assignee: Bruker HTS GmbH
    Inventor: Alexander Usoskin
  • Patent number: 8112134
    Abstract: The superconducting current-limiting device contains at least one coil (61), the conductive track of which is formed from at least one band-shaped superconductor (17), where a holding element (2, 41, 10, 51, 62) is located between adjacent coil windings. The holding element (2, 41, 51, 62) is constructed wider than the superconductor (17) in the axial direction of the coil (61). The holding element (2, 41, 51, 62) further includes a flat strip (11) and an undulating strip (12, 42, 52). The flat strip (11) extends essentially parallel to the band-shaped superconductor (17) at an essentially constant distance (22) therefrom. The undulating strip (12, 42, 52) extends essentially parallel to the flat strip (11), and in the longitudinal direction periodically has regions (15, 43, 53) distant from and regions (13) close to the flat strip (11). The regions (13) of the undulating strip (12, 42, 52) near to the flat strip have a mechanical connection (21) to the flat strip (11).
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: February 7, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hans-Peter Krämer, Manfred Wohlfart
  • Patent number: 7996053
    Abstract: The present invention relates to a quench controlled high temperature superconductor component wherein at least one depression is provided in a surface of the component resulting in a reduced wall thickness, and, wherein an electrical shunt is applied into the depression.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: August 9, 2011
    Assignee: Nexans
    Inventors: Heribert Walter, Joachim Bock, Robert Dommerque, Sergej Bemert
  • Publication number: 20110032650
    Abstract: The present invention relates to a reclosing control system and method using a superconducting fault current limiter. The reclosing control system includes a superconducting fault current limiting device in which two circuits, each having a switch and a superconducting fault current limiter connected in series with each other, are connected in parallel with each other. A recloser is disposed between the superconducting fault current limiting device and a distribution line and is configured to control reclosing. The distribution line is connected to the recloser and is configured to transfer power to a load.
    Type: Application
    Filed: February 3, 2010
    Publication date: February 10, 2011
    Applicant: SUNGKYUNKWAN UNIVERSITY FOUNDATION FOR CORPORATE COLLABORATION
    Inventors: Kim Chul Hwan, Rhee Sang Bong, Seo Hun Chul, Ko Yun Tae
  • Publication number: 20100309590
    Abstract: A fault current limiter designed for connection into a medium voltage, high voltage, or extra-high voltage substation or other high voltage source such as a generator station, the limiter including: a ferromagnetic circuit formed from a ferromagnetic material and including at least a first limb, a second limb and a third limb; a first input phase coil wound around the first limb, a second output phase coil wound around the third limb; a saturation mechanism surrounding a limb for magnetically saturating the ferromagnetic material; a containment vessel providing a substantially uniform, low electrical conductivity medium surrounding the ferromagnetic circuit, the phase coils and the saturation mechanism.
    Type: Application
    Filed: October 30, 2008
    Publication date: December 9, 2010
    Applicant: Zenergy Power Pty Ltd.
    Inventor: Francis Anthony Darmann
  • Publication number: 20100254048
    Abstract: A fault current limiter including: a ferromagnetic circuit formed from a ferromagnetic material and including at least a first limb, and a second limb; a saturation mechanism surrounding a limb for magnetically saturating the ferromagnetic material; a phase coil wound around a second limb; a dielectric fluid surrounding the phase coil; a gaseous atmosphere surrounding the saturation mechanism.
    Type: Application
    Filed: November 27, 2008
    Publication date: October 7, 2010
    Inventor: Francis Anthony Darmann
  • Patent number: 7558030
    Abstract: A resistive superconducting fault current limiter comprises: a superconducting limiter element which is in a superconductive state in the event of a normal current occurrence, and which is in a normal conductive state having a predetermined resistance when a fault current larger than a predetermined threshold current value flows; a superconducting serial coil serially connected to the superconducting limiter element so as to face each other so that a current loss can be minimized accordingly as currents flow in opposite directions thus to cancel magnetic fields, and having a threshold current value greater than the threshold current value of the superconducting limiter element by a predetermined ratio; and a normal conductor parallel coil connected to the superconducting limiter element in parallel and having a predetermined resistance smaller than the resistance of the superconducting limiter element when a fault current occurs, for preventing the superconducting limiter element from being overheated by divi
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: July 7, 2009
    Assignee: LS Industrial System Co., Ltd.
    Inventors: Bang-Wook Lee, Kwon-Bae Park
  • Patent number: 7551410
    Abstract: A fault current limiter for limiting current faults in an electrical network comprising: a series of phase coils located adjacent a superconductive coil for fault current limiting phase faults within the network; a series of neutral coils located adjacent the superconductive coil for fault current limiting neutral earthing faults in the electrical network.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: June 23, 2009
    Assignee: S C Power Systems, Inc.
    Inventor: Francis Anthony Darmann
  • Publication number: 20090086386
    Abstract: A fault current limiter comprising: an input node; an output node; a variable impedance element coupled between the input node and the output node; a closed loop cryocooler circuit, comprising a first cryocooler for cooling the variable impedance element and a second cryocooler, thermally coupled to the first cryocooler, for cooling the first coolant, wherein the variable impedance element comprises Magnesium Diboride.
    Type: Application
    Filed: September 23, 2008
    Publication date: April 2, 2009
    Inventors: Philip M. Sargent, Peter Malkin, Brian E. Simmers
  • Publication number: 20090046399
    Abstract: A superconducting coil quench detection method and device capable of detecting a quench detection voltage even in a superconducting coil where a plurality of element coils are connected with a plurality of current sources and operated with repetitive pulses or AC and a voltage of several kV is applied continuously as an induction voltage. A super conducting power storage unit is also provided. The quench detection device comprises a pickup coil (2) provided in a superconducting coil (1) or in the vicinity thereof, an overvoltage protection circuit (4) a voltage signal below a predetermined level by receiving the difference between a voltage induced in the superconducting coil (1) at the time of quenching of the superconducting coil (1) and a voltage induced in the pickup coil (2), and a quench detector (3) for detecting quench of the superconducting coil (1) by receiving the voltage signal.
    Type: Application
    Filed: April 18, 2006
    Publication date: February 19, 2009
    Inventors: Tsutomu Kurusu, Michitaka Ono, Taizo Tosaka, Yusuke Ishii, Yasuhiro Yamashita
  • Publication number: 20080293577
    Abstract: A method of operating a superconductor in its superconductivity state at a temperature Tc(i) in the range of Tc* to Tc, where Tc* is greater than the superconductivity temperature Tc of the superconductor, includes cooling the superconductor to a temperature of Tc or less and applying energy to the superconductor after the superconductor has entered a superconducting state. The energy corresponds to the quantum energy hv in the range of a minimum energy less than E0 to less than E0, where E0 is the ground state of the two-dimensional excitation binding energy of the superconductor The superconductor is then cooled to the selected temperature Tc(i). The minimum energy is 8/9 of E0.
    Type: Application
    Filed: December 26, 2006
    Publication date: November 27, 2008
    Applicant: CZT Inc.
    Inventors: Kai Wai Wong, Susana Curatolo
  • Patent number: 7394628
    Abstract: An apparatus for regulation of electrical power has a superconducting member exhibiting a capability of quenching at the electrical current exceeding a threshold value, a metallic member coupled to the superconducting member, a thermally insulated and tight internal container filled with a portion of a liquid fraction of a cooling agent and a portion of a gas fraction of the cooling agent. The internal container being capable to provide a cooling of the superconducting member and the metallic member by their direct contact with the liquid fraction of the cooling agent in and to provide a mass exchange of the cooling agent between the internal container and an external container. The mass exchange of the cooling agent has a mass flow controller for the cooling agent which is output from the inner container; a controller of an instantaneous pressure in the internal container, and a delay circuit providing a pre-determined time-delay for mass flow controller operation.
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: July 1, 2008
    Assignee: European High Temperature Superconductors
    Inventor: Alexander Usoskin
  • Patent number: 7375933
    Abstract: In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: May 20, 2008
    Inventor: Kasegn D. Tekletsadik
  • Patent number: 7193825
    Abstract: A superconducting current limiting device (30) comprising: an interconnected high magnetic permeability structure including a central core (50) interconnected to at least a first and second arm (31, 32) branching off therefrom; a superconductive coil (33, 34) surrounding the central core for biasing the central core; a first alternating current coil (36, 37) surrounding the first arm and interconnected to an alternating current source; a second alternating current coil (38, 39) surrounding a second arm and interconnected to an alternating current load; the first and second alternating current coils being magnetically coupled to the central core wherein the device operates so as to limit the current passing through the device upon the occurrence of a fault condition in the load.
    Type: Grant
    Filed: October 21, 2003
    Date of Patent: March 20, 2007
    Assignee: Metal Manufactures Limited
    Inventors: Francis Anthony Darmann, Timothy Paul Beales
  • Patent number: 6900714
    Abstract: A system and method for protecting a superconductor. The system may comprise a current sensor operable to detect a current flowing through the superconductor. The system may comprise a coolant temperature sensor operable to detect the temperature of a cryogenic coolant used to cool the superconductor to a superconductive state. The control circuit is operable to estimate the superconductor temperature based on the current flow and the coolant temperature. The system may also be operable to compare the estimated superconductor temperature to at least one threshold temperature and to initiate a corrective action when the superconductor temperature exceeds the at least one threshold temperature.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: May 31, 2005
    Assignee: General Electric Company
    Inventors: Xianrui Huang, Evangelos Trifon Laskaris, Kiruba Haran Sivasubramaniam, James William Bray, David Thomas Ryan, James Michael Fogarty, Albert Eugene Steinbach
  • Patent number: 6809910
    Abstract: A method and apparatus for magnetically triggering a superconductor in a superconducting fault current limiter to transition from a superconducting state to a resistive state. The triggering is achieved by employing current-carrying trigger coil or foil on either or both the inner diameter and outer diameter of a superconductor. The current-carrying coil or foil generates a magnetic field with sufficient strength and the superconductor is disposed within essentially uniform magnetic field region. For superconductor in a tubular-configured form, an additional magnetic field can be generated by placing current-carrying wire or foil inside the tube and along the center axial line.
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: October 26, 2004
    Assignee: SuperPower, Inc.
    Inventors: Xing Yuan, Drew Willard Hazelton, Michael Stephen Walker
  • Patent number: 6337785
    Abstract: A superconducting fault current limiter is provided which is capable of ensuring a sufficient impedance for restricting an excessive current flow caused by an accident and completely satisfying a canceling condition of a magnetic field during normal operation without using an iron core. The fault current limiter includes first superconducting coils and second superconducting coils including windings of superconducting lines. First superconducting coils are electrically connected in series with second superconducting coils. First superconducting coils and second superconducting coils generate magnetic fields in opposite directions by application of currents. The fault current limiter further includes a component selected from a group consisting of a resistor and an inductor, the component being electrically connected in parallel with second superconducting coils. First superconducting coils and second superconducting coils are alternately arranged in a ring form such that a coil axis is circular.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: January 8, 2002
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Toru Okazaki
  • Patent number: 5999383
    Abstract: A multi-stranded superconducting coil includes compensation windings for use in detection of quenches in the coil. The compensation windings are formed as an integral part of the coil by co-winding a non-superconducting strand along with the superconducting strands in the cable manufacturing process. The non-superconducting strand is cut and electrically connected to the coil at selected locations.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: December 7, 1999
    Assignee: Siemens Westinghouse Power Corporation
    Inventors: David J. Hall, Owen R. Christianson
  • Patent number: 5930095
    Abstract: A superconducting current limiting device protects an electric circuit from a fault current. The device comprises a magnetically saturable core having saturated and non-saturated states and an input coil for electrically coupling the core to the electric circuit, the input coil drawing a current therethrough so that a magnetic flux is generated in the core due to the current. Further, the core includes a main path for drawing the generated magnetic flux and at least two magnetic paths, a first of the magnetic paths drawing a first portion of the magnetic flux, and a second of the magnetic paths drawing a second portion of the magnetic flux and having a damping element for cancelling at least a fraction of the second portion of the magnetic flux to thereby prevent the core from getting into the saturated state.
    Type: Grant
    Filed: September 4, 1998
    Date of Patent: July 27, 1999
    Assignees: Back Joo, Min-Seok Joo
    Inventors: Back Joo, Min-Seok Joo, Tae-Kuk Ko
  • Patent number: 5862028
    Abstract: Quenching of a coil for a superconducting magnet is detected by placing a temperature sensor proximate the coil of the superconducting magnet and monitoring the temperature sensor for a rise in temperature of the coil of the superconducting magnet. AC and DC field variations of the coil of the superconducting magnet do not substantially adversely affect such temperature monitoring, thus facilitating reliable and accurate detection of such quenching. This accurate and reliable detection of quenching assures that the superconducting magnet can be shut down in a controlled manner, so as to prevent damage thereto when quenching occurs. The method and apparatus of the present invention finds particular use in maglev applications.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: January 19, 1999
    Assignee: Northrop Grumman Corporation
    Inventor: Swarn S. Kalsi
  • Patent number: 5617280
    Abstract: A current limiter having a plurality of current limiting units provided for electric paths constituting a plurality of phases. Each current limiting unit is constituted by a superconducting coil functioning as a first current limiting element formed in a non-inductive winding manner by connecting two superconducting coils in series, which superconducting coils are wound in opposite directions and equal in size and number of turns, and a superconducting coil functioning as a second current limiting element connected in parallel to the first current limiting element and having a predetermined impedance value. These current limiting units are contained within a cryostat and separated by a magnetic shield member for electromagnetically isolating the respective phases.
    Type: Grant
    Filed: December 12, 1994
    Date of Patent: April 1, 1997
    Assignees: The Tokyo Electric Power Company, Incorporated, Kabushiki Kaisha Toshiba
    Inventors: Tsukushi Hara, Takeshi Ohkuma, Takahiko Yamamoto, Daisuke Ito, Kazuyuki Tsurunaga, Takamitsu Tada
  • Patent number: 5600522
    Abstract: A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: February 4, 1997
    Assignee: ARCH Development Corporation
    Inventor: John R. Hull
  • Patent number: 5596469
    Abstract: An electrical fault limiter having first, second, third, and fourth magnetic cores. The first magnetic core opposes the second magnetic core and is adjacent to the third magnetic core. The fourth magnetic core opposes the third magnetic core and is adjacent to the second magnetic core. A rotor is disposed between the first and second magnetic cores, and the third and fourth magnetic cores. The rotor is rotatable about a rotor axis. The first and second magnetic cores are disposed on a first side of the rotor axis and the third and fourth magnetic cores are disposed on a second side of the rotor axis. Each core has a first arm, a second arm and a body to which the first and second arms are connected. Each body has a superconduction bias coil disposed about it. Each arm has a conduction mode coil disposed about it.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: January 21, 1997
    Assignee: Power Superconductor Applications Co.
    Inventor: Stephen B. Kuznetsov
  • Patent number: 5546261
    Abstract: A superconducting fault current limiter composed of an induction coil wound around a core made of a soft magnetic material such as soft iron, ferrite or the like, a cylindrical superconductive body arranged in surrounding relationship with the induction coil and a cooling container formed to contain only the superconductive body therein and filled with cooling liquid such as liquid nitrogen or helium to immerse therein the superconductive body.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: August 13, 1996
    Assignee: NGK Insulators, Ltd.
    Inventors: Shinji Yoshida, Shuichiro Motoyama, Takashi Ohashi, Masamichi Ishihara
  • Patent number: 5476719
    Abstract: A multi-layer microstrip structure includes a substrate and a first superconducting layer deposited on the substrate. A first dielectric layer, made at least partially of benzocyclobutene (BCB), is deposited on the first superconducting layer. Additional superconducting dielectric and superconducting layers can be employed. Preferably the superconducting layers are made from niobium. The multilayer microstrip structure is ideally suited for use in passive circuit components of microwave circuits and in multi-chip modules.
    Type: Grant
    Filed: August 17, 1994
    Date of Patent: December 19, 1995
    Assignee: TRW Inc.
    Inventors: Robert D. Sandell, Andrew D. Smith
  • Patent number: 5379020
    Abstract: In the case of high-temperature superconductors (6) which are used as inductive current limiters, unless any special precautionary measure is taken, there is a risk that short-circuit currents can lead to local stress centers and hot spots, and to local destruction of the high-temperature superconductor. In order to avoid this, a hollow cylinder (SL) of the high-temperature superconductor (6) is coated with a 1 .mu.m thick conductive-silver layer (E1). A second 10 .mu.m thick metal layer of foil made of silver or aluminum can be deposited thereon. In order to reduce or to avoid tensile stresses in the ceramic of the hollow cylinder (SL) made of a high-temperature superconductor, and in order to reduce the electrical contact resistance of the metal layers, this hollow cylinder (SL) has a mechanical reinforcing element (7), made of an elastic steel wire, wound around it, at room temperature, under tensile stress.
    Type: Grant
    Filed: May 16, 1994
    Date of Patent: January 3, 1995
    Assignee: ABB Research Ltd.
    Inventors: Jurg Meier, Willi Paul
  • Patent number: 5334964
    Abstract: A device having cores of metal oxide ceramic (for example, Y-Ba-Cu-O) for limiting a short circuit current in power supply systems. The concept provides that a choke core, when operated at a rated current, is superconductive and its shielding currents keep the resulting inductance in the choke at a low level. In the event of an overload, the winding of the choke generates a correspondingly high magnetic field in the core which puts the core into the normally conducting state. This causes the shielding currents to disappear in connection with a rise in the resulting inductance, thus limiting the current. In order to realize a particularly high inductance in the normally conductive case, the superconductive choke core may be made hollow and may be filled at least in part with a ferromagnetic material.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: August 2, 1994
    Assignee: Licentia Patent-Verwaltungs-GmbH
    Inventors: Heinz Voigt, Roland Fischer, Rudolf Schneider
  • Patent number: 5250508
    Abstract: The invention relates to superconductor current-limiting apparatus of the type having a magnetic core around which firstly a superconductor component is disposed, followed by an electric coil made of non-superconducting material, the apparatus being designed to be inserted in a line to be protected (L), the assembly constituted by the magnetic core (6A, 6B), the superconductor component (3A, 3B) and the electric coil (2A, 2B) forming a current-limiting unit which is connected in the line to be protected in series with a circuit-breaker.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: October 5, 1993
    Assignee: Gel Alsthom SA
    Inventor: Van Doan Pham
  • Patent number: 5225956
    Abstract: In a superconducting AC (alternating current) current limiter, quenched trigger coil assembly is quickly recovered to the superconductive state by minimizing a loop current flowing through the trigger coil assembly.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: July 6, 1993
    Assignees: The Tokyo Electric Power Company, Incorporated, Kabushiki Kaisha Toshiba
    Inventors: Tsukushi Hara, Kiyoshi Okaniwa, Kazuyuki Tsurunaga, Mitsuhito Sawamura, Yoshihisa Masuda, Daisuke Ito
  • Patent number: 5225957
    Abstract: An improvement of a current limiting device using a superconductive coil. A trigger coil and current limiting coils are formed as a superconductive coil. A switching element which is actuated when a current limiting operation by the current limiting coil occurs, is connected in series to the trigger coil to immediately suppress heat generation by the trigger coil. When a quenching is detected by a detector, the trigger coil is disconnected and an additionally provided recovery coil is connected to speed up the recovery operation. A plurality of trigger coils connected in series may be used.
    Type: Grant
    Filed: May 22, 1990
    Date of Patent: July 6, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kazuyuki Tsurunaga
  • Patent number: 5218505
    Abstract: A superconducting coil system includes an excitation power source, a superconducting coil, a DC circuit breaker connected in series between the excitation power source and the superconducting coil to disconnect them when quenching occurs, a protective resistor connected in a parallel manner to the superconducting coil for dissipating the energy accumulated in the superconducting coil when the quenching occurs, and a switch provided as a bypass of the DC circuit breaker, the switch being closed during the normal operation to pass the energy from the excitation power source to the superconducting coil through a resistor and being opened when the quenching occurs.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: June 8, 1993
    Assignees: Hitachi, Ltd., Hitachi Engineering Service Co., Ltd.
    Inventors: Morihiro Kubo, Yukio Ishigaki
  • Patent number: 5216568
    Abstract: A superconducting magnet device which is capable of protecting at the time of quenching a superconducting magnet divided into a plurality of sections comprises a superconducting magnet circuit which is formed by sequentially connecting in series coil pairs 1a, 1b, and 2a, 2b which are positioned symmetrically with respect to a ferromagnetic shield 6, and by connecting in parallel to the superconducting coils 1a, 1b and 2a, 2b superconducting coil protecting elements 3a and 3b which protect the superconducting coils 1a, 1b and 2a, 2b when the voltage at the ends of the coils has exceeded a predetermined value. If quenching occurs at the superconducting coils 1a, 1b and 2a, 2b, generation of an unbalanced electromagnetic force, a local electromagnetic force, etc., against the ferromagnetic shield 6 is prevented, so that the support structure for the superconducting coils and the ferromagnetic shield can be simplified.
    Type: Grant
    Filed: December 13, 1989
    Date of Patent: June 1, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akihiro Harada, Akinori Yamasaki, Tatsuya Oue
  • 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: 5153804
    Abstract: A hybrid current limiter comprising a first winding of non-superconducting conductive material having a large number of turns and electrically connected in series with a superconductoring coil of low self-inductance and placed in a cryostat, and a second winding of non-superconducting conductive material having a small number of turns, said second winding being closely coupled with said first winding in such a manner as to obtain low overall inductance, the second winding being connected in parallel with the series circuit constituted by the first winding and the superconducting coil.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: October 6, 1992
    Assignee: GEC Alsthom SA
    Inventors: Van Doan Pham, Jean-Pierre Dupraz, Michel Collet, Yves Brunet, Pascal Tixador
  • Patent number: 5140290
    Abstract: A device for inductive current limiting of an alternating current consisting of an induction coil (2), which includes at least one winding and through which current flows, a body (3) made of a ceramic high-temperature superconductor arranged concentrically to the latter and having a centrosymmetrical form which is hollow in the interior, and having located in the interior of said body (3) a concentrically arranged core (4) made of a soft magnetic material of high permeability. In normal operation (rated current), the superconductivity of the body (3) is effective and impedance of the induction coil (2) is very low. With overcurrent (mains short-circuit) the superconductivity disappears and the impedance of the induction coil (2) reaches its maximum, current-limiting value.
    Type: Grant
    Filed: November 14, 1991
    Date of Patent: August 18, 1992
    Assignee: Asea Brown Boveri Ltd.
    Inventor: Helmut Dersch
  • Patent number: 5121281
    Abstract: The invention relates to a circuit breaker for limiting a direct current and comprising a combination of first means including superconducting windings for limiting the current and second means for interrupting the residual current. The invention is applicable to interrupting high tension direct currents.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: June 9, 1992
    Assignee: GEC Alsthom SA
    Inventors: Van Doan Pham, Michel Collet, Mohamed Bekhaled, Thierry Verhaege
  • Patent number: 5067044
    Abstract: A quench detector for a superconducting coil is provided which utilizes an optical coupling and a rotary encoder. The presence of a resistive voltage in the superconducting coil created by a quench will cause a rotatable readout coil to move. Movement of the readout coil will be detected by light passing through or reflected by an optical encoder, which will interrupt or transmit light passing from one or more light sources towards one or more light sensors. Preferred embodiments utilize optic fibers for the light sources and sensors, which are unaffected by the high magnetic fields or hostile environment of the superconductor coil.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: November 19, 1991
    Assignee: Westinghouse Electric Corp.
    Inventors: George T. Mallick, Jr., James R. Logan, David Marschik
  • Patent number: 5063472
    Abstract: Device for detecting the quenching of part a superconducting element comprising two identical superconducting conductors electrically connected in parallel is provided with means (104, 105, 109, 110) of detecting a difference in intensity or phase between the currents flowing in the conductors. An application to a superconducting current limiter is described.
    Type: Grant
    Filed: April 2, 1990
    Date of Patent: November 5, 1991
    Assignee: GEC Alsthom SA
    Inventors: Pham van Doan, Jean-Pierre Dupraz, Alain Fevrier
  • Patent number: 5021914
    Abstract: There is disclosed a superconducting switch including two superconducting coils wound on a common bobbin wherein these coils have the same critical current value, and are connected in parallel so that magnetomotive forces which are the same in magnitude and opposite to each other in direction are produced. This superconducting switch is non-inductive and responds to an overcurrent to securely operated at a high speed. There is also disclosed a current limiter including a current limiting coil connected in parallel with the superconducting switch used as a trigger coil. The superconducting switch exists within a magnetic field produced by the current limiting coil. There is further disclosed a current limiter such that the current limiting coil is constructed to be of non-inductive type using two coils, and a superconducting switch is connected to either of these coils.
    Type: Grant
    Filed: July 13, 1989
    Date of Patent: June 4, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuyuki Tsurunaga, Yoshihisa Masuda, Hiroyuki Okumura, Daisuke Ito
  • Patent number: 4994932
    Abstract: A superconducting current limiting apparatus includes a first container, a superconducting current limiting element accommodated in the first container, a refrigerant filling the first container for cooling the superconducting current limiting element accommodated in the first container, a second container for accommodating the first container in such a manner that the first container is heat insulated, and a conductor for connecting the superconducting current limiting element to an external power supply system. Such a superconducting current limiting apparatus can be used to limit a short-circuit current. It can be incorporated in a short circuit controlling superconducting system.
    Type: Grant
    Filed: January 26, 1990
    Date of Patent: February 19, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masaru Okamoto, Hitoshi Mizoguchi, Masayuki Ishikawa, Hisatoshi Ikeda, Katsumi Suzuki, Susumu Nishiwaki, Tsuneharu Teranishi, Satoru Yanabu, Tsutomu Fujioka