Patents by Inventor Kyeong Dal Choi

Kyeong Dal Choi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8788227
    Abstract: A method for measuring critical current density of superconductor wires according to the present invention is characterized in that it includes: (a) applying an external magnetic field to the superconductor wires, (b) measuring a magnetization loss of the superconductor wires according to the application of the external magnetic field, (c) normalizing the measured magnetization loss, and then calculating a fully-penetration magnetic field of the superconductor wires according to the normalized magnetization loss, (d) calculating a critical current density of the superconductor wires according to the calculated fully-penetration magnetic field. Therefore, the critical current density of parallel superconductor wires such as stacked superconductor wires may be measured without applying current to the superconductor wires directly.
    Type: Grant
    Filed: July 28, 2010
    Date of Patent: July 22, 2014
    Assignees: Korea Polytechnic University Industry Academic Cooperation Foundation, Woosuk University Industry Academic Cooperation Foundation
    Inventors: Kyeong Dal Choi, Ji Kwang Lee, Woo Seok Kim, Chan Park, Byung Wook Han, Se Yeon Lee
  • Patent number: 8322019
    Abstract: Provided is a multiple transposition method for superconducting wire, by making each superconducting wire unit from second-generation superconducting wires that were firstly transposed and then transposing each superconducting wire unit in such a manner that the phase of each unit can be changed along the length, comprising preparing wires by making curves on superconducting wires in such a manner that the superconducting wires of a thin multiple layer grown epitaxially are slit in zigzags and then making the curves repeatedly and by machining the wires with a desired length; making first-transposed superconducting wire units by combining a plurality of the prepared wires such that curves of adjacent wires come in touch to each other and are superposed; preparing a superconducting wire unit bundle by arranging the first-transposed superconducting wires units and by locating a plurality of the first-transposed superconducting wire units in parallel along the length; and making a second transposition on the fir
    Type: Grant
    Filed: July 5, 2010
    Date of Patent: December 4, 2012
    Assignees: Korea Polytechnic University Industry Academic Cooperation Foundation, Woosuk University Industry Academic Cooperation Foundation
    Inventors: Kyeong Dal Choi, Ji Kwang Lee, Woo Seok Kim, Chan Park, Yung Il Kim
  • Patent number: 8089332
    Abstract: The present invention relates to a superconducting power transforming apparatus. The superconducting power transforming apparatus according to the present invention comprises a transformer housing having a transforming cable passing hole and filled with a liquid cooling means; a superconducting transformer housed in the transformer housing in a state that the superconducting transformer is immersed in the liquid cooling means; a tap changer housing having a tap changing cable passing hole and vacuum-sealed from outside; a power tap changer housed in the vacuum tap changer housing; and a cable linking pipe vacuum-sealed from the transformer housing and the tap changer housing, and linking the transforming cable passing hole with the tap changing passing hole in order that a transformer winding tap cable connecting the superconducting transformer and the power tap changer passes through.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: January 3, 2012
    Assignee: Korea Polytechnic University Industry Academic Cooperation Foundation
    Inventors: Kyeong-Dal Choi, Ji-Kwang Lee, Woo-Seok Kim, Chan Park, Sun-Bok Choi
  • Publication number: 20110270557
    Abstract: A method for measuring critical current density of superconductor wires according to the present invention is characterized in that it includes: (a) applying an external magnetic field to the superconductor wires, (b) measuring a magnetization loss of the superconductor wires according to the application of the external magnetic field, (c) normalizing the measured magnetization loss, and then calculating a fully-penetration magnetic field of the superconductor wires according to the normalized magnetization loss, (d) calculating a critical current density of the superconductor wires according to the calculated fully-penetration magnetic field. Therefore, the critical current density of parallel superconductor wires such as stacked superconductor wires may be measured without applying current to the superconductor wires directly.
    Type: Application
    Filed: July 28, 2010
    Publication date: November 3, 2011
    Applicant: Korea Polytechnic University Industry Academic Cooperation Foundation
    Inventors: Kyeong Dal Choi, Ji Kwang Lee, Woo Seok Kim, Chan Park, Byung Wook Han, Se Yeon Lee
  • Patent number: 8043429
    Abstract: The present invention relates to a method for fabricating a filament type high-temperature superconducting wire in which a thin film type high-temperature superconducting wire is fabricated into a filament shape suitable for use with alternating current.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: October 25, 2011
    Assignee: Korea Polytechnic University
    Inventors: Hee Gyoun Lee, Gye Won Hong, Kyeong Dal Choi
  • Patent number: 8035933
    Abstract: Disclosed is the structure of a persistent current switch and a control method for the same. In the switch structure, a portion of a superconducting wire to be used as a switch is formed with slits such that the flow of current is controlled by the switch, to facilitate a transition between the superconducting state and the normal state of the superconducting wire. The structure of the persistent current switch includes a first slit longitudinally extending from a first point on one end of a superconducting wire to a second point and from a third point to a fourth point, the second, third, and fourth points being arranged sequentially in a longitudinal line, and second and third slits provided at opposite sides of a region between the second point and the third point where no first slit exists.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: October 11, 2011
    Assignee: Korea Polytechnic University Industry Academic Cooperation Foundation
    Inventors: Hee-Gyoun Lee, Gye-Won Hong, Kyeong Dal Choi, Seung Wook Lee
  • Publication number: 20110239443
    Abstract: Provided is a multiple transposition method for superconducting wire, by making each superconducting wire unit from second-generation superconducting wires that were firstly transposed and then transposing each superconducting wire unit in such a manner that the phase of each unit can be changed along the length, comprising preparing wires by making curves on superconducting wires in such a manner that the superconducting wires of a thin multiple layer grown epitaxially are slit in zigzags and then making the curves repeatedly and by machining the wires with a desired length; making first-transposed superconducting wire units by combining a plurality of the prepared wires such that curves of adjacent wires come in touch to each other and are superposed; preparing a superconducting wire unit bundle by arranging the first-transposed superconducting wires units and by locating a plurality of the first-transposed superconducting wire units in parallel along the length; and making a second transposition on the fir
    Type: Application
    Filed: July 5, 2010
    Publication date: October 6, 2011
    Applicant: Korea Polytechnic University Industry Academic Cooperation Foundation
    Inventors: Kyeong Dal Choi, Ji K wang Lee, Woo Seok Kim, Chan Park, Yung II Kim
  • Publication number: 20110218110
    Abstract: The present invention relates to a superconducting power transforming apparatus. The superconducting power transforming apparatus according to the present invention comprises a transformer housing having a transforming cable passing hole and filled with a liquid cooling means; a superconducting transformer housed in the transformer housing in a state that the superconducting transformer is immersed in the liquid cooling means; a tap changer housing having a tap changing cable passing hole and vacuum-sealed from outside; a power tap changer housed in the vacuum tap changer housing; and a cable linking pipe vacuum-sealed from the transformer housing and the tap changer housing, and linking the transforming cable passing hole with the tap changing passing hole in order that a transformer winding tap cable connecting the superconducting transformer and the power tap changer passes through.
    Type: Application
    Filed: November 19, 2009
    Publication date: September 8, 2011
    Applicant: KOREA POLYTECHNIC UNIVERSITY
    Inventors: Kyeong-Dal Choi, Ji-Kwang Lee, Woo-Seok Kim, Chan Park, Sun-Bok Choi
  • Patent number: 7920977
    Abstract: A noncontact method for measuring currents flowing through superconductive wires connected in parallel is provided.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: April 5, 2011
    Assignee: Korea Polytechnic University
    Inventors: Kyeong Dal Choi, Ji Kwang Lee, Seung Wook Lee, Chan Park, Woo Seok Kim
  • Publication number: 20090314617
    Abstract: Disclosed is the structure of a persistent current switch and a control method for the same. In the switch structure, a portion of a superconducting wire to be used as a switch is formed with slits such that the flow of current is controlled by the switch, to facilitate a transition between the superconducting state and the normal state of the superconducting wire. The structure of the persistent current switch includes a first slit longitudinally extending from a first point on one end of a superconducting wire to a second point and from a third point to a fourth point, the second, third, and fourth points being arranged sequentially in a longitudinal line, and second and third slits provided at opposite sides of a region between the second point and the third point where no first slit exists, the second and third slits having a length longer than a distance between the second point and the third point.
    Type: Application
    Filed: October 10, 2007
    Publication date: December 24, 2009
    Inventors: Hee-Gyoun Lee, Gye-Won Hong, Kyeong Dal Choi, Seung Wook Lee
  • Publication number: 20090105973
    Abstract: A noncontact method for measuring currents flowing through superconductive wires connected in parallel is provided.
    Type: Application
    Filed: March 6, 2008
    Publication date: April 23, 2009
    Inventors: Kyeong Dal CHOI, Ji Kwang Lee, Seung Wook Lee, Chan Park, Woo Seok Kim
  • Patent number: 7383625
    Abstract: Disclosed is a method of manufacturing a continuous disk winding. A high-temperature superconducting wire is lapped using Kapton films to insulate the high-temperature superconducting wire. The high-temperature superconducting wire is wound on a bobbin by a predetermined number of turns to form a layer of windings. An annular disk having a slit formed therein is fitted onto the bobbin. The slit is formed along the circumference of the disk and to be inclined from the inner side of the disk towards the outer side thereof. The high-temperature superconducting wire is inserted into the slit of the disk to pass through the annular disk smoothly along the inclined slit and wound again by the predetermined number of turns to form a next layer of windings. The above steps of fitting an annular disk, and inserting and winding the high-temperature superconducting wire are repeated to form multiple layers of windings.
    Type: Grant
    Filed: April 28, 2006
    Date of Patent: June 10, 2008
    Assignee: Korea Polytechnic University
    Inventors: Kyeong Dal Choi, Woo Seok Kim, Seung Wook Lee, Young In Hwang
  • Publication number: 20080113870
    Abstract: The present invention relates to a method for fabricating a filament type high-temperature superconducting wire in which a thin film type high-temperature superconducting wire is fabricated into a filament shape suitable for use with alternating current.
    Type: Application
    Filed: March 28, 2007
    Publication date: May 15, 2008
    Applicant: KOREA POLYTECHNIC UNIVERSITY
    Inventors: Hee Gyoun LEE, Gye Won HONG, Kyeong Dal CHOI
  • Patent number: 7227438
    Abstract: The present invention discloses a superconducting wire transposition method and superconducting transformer whose winding is formed of superconducting wire to enable the formation of transpositions. The superconducting wire transposition method characterized of different winding start positions of at least two disks wound with a plurality of parallel superconductive wires, and usage of different superconducting wires for conductors to be connected between the disks, thereby forming transpositions outside of the disks. Preferably, part of the plurality of disks are rotatably assembled in pairs so as to form transpositions while maintaining a total number of windings equally. Therefore, according to the present invention, transpositions can be formed without bending or welding superconducting wires and thus, deteriorations in superconductivity can be prevented.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: June 5, 2007
    Assignee: Hyosung Corporation
    Inventors: Hee Suck Song, Woo Heng Heo, Jung Ho Park, Kyeong Dal Choi, Woo Seok Kim, Sung Hoon Kim
  • Publication number: 20070052506
    Abstract: The present invention discloses a superconducting wire transposition method and superconducting transformer whose winding is formed of superconducting wire to enable the formation of transpositions. The superconducting wire transposition method characterized of different winding start positions of at least two disks wound with a plurality of parallel superconductive wires, and usage of different superconducting wires for conductors to be connected between the disks, thereby forming transpositions outside of the disks. Preferably, part of the plurality of disks are rotatably assembled in pairs so as to form transpositions while maintaining a total number of windings equally. Therefore, according to the present invention, transpositions can be formed without bending or welding superconducting wires and thus, deteriorations in superconductivity can be prevented.
    Type: Application
    Filed: December 30, 2004
    Publication date: March 8, 2007
    Inventors: HEE SUCK SONG, WOO HENG HEO, JUNG HO PARK, KYEONG DAL CHOI, WOO SEOK KIM, SUNG HOON KIM