Korea Polytechnic University Industry Academic Cooperation Foundation

Korea Polytechnic University

Woosuk University Industry Academic Cooperation Foundation

Hyosung Corporation

Kyeong Dal Choi

Woo Seok Kim

Chan Gook Park

Seung Wook Lee

Ji Kwang Lee

Sung Hoon Kim

Gye-Won Hong

Hee-Gyoun Lee

Yung Il Kim

Young In Hwang

Gye Won Hong

Se Yeon Lee

Jung Ho Park

Hee Suck Song

Hee Gyoun Lee

Woo Heng Heo

Byung Wook Han

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.

Measuring method of critical current density of superconductor wires using measurement of magnetization loss

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 first-transposed superconducting wire units by rotating the plurality of superconducting wire units on the central axis of the superconducting wire unit bundle along the length to be twisted and combined with each other.

Multiple transposition method for superconducting wire

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. The method includes depositing a conducting ceramic or metal epitaxially on a metal substratehaving bi-axially textured property to deposit a conductive thin film layer(S); depositing silver, copper, nickel, silver and copper, or a nickel alloy epitaxially on the deposited conductive thin film layerto deposit a metal layer(S); cutting the deposited metal layerinto a filament shape having a predetermined width using a laser, a slitter, or etching and separating the cut metal layer from the conductive film layerby selective etching, stress generation, or a difference in thermal expansion coefficients to form a metal filament(S); coating a single layer or multi-layers of a ceramic buffer layeron the outside of the separated metal filament(S); coating a superconducting layeron the outside of the ceramic buffer layer(S); and coating a single layer or multi-layers of a metal protective layeron the outside of the superconducting layer(S).

Method for fabricating filament type high-temperature superconducting wire

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.

Structure of persistent current switch and that of control method

A noncontact method for measuring currents flowing through superconductive wires connected in parallel is provided. The method includes arranging hall sensors for measuring voltage levels based on magnetic fields generated around the superconductive wires, setting a matrix relation between the measured voltage values, values of currents flowing through the superconductive wires, and a variable matrix having variables defining relations between the voltage values and the current values, applying predetermined current levels to the superconductive wires a number of times and measuring voltage values through the hall sensors, substituting the predetermined current values and the measured voltage values into the matrix relation to calculate the variables of the variable matrix, and substituting the calculated variable matrix and unknown voltage values, measured by the hall sensors when unknown currents flow through the superconductive wires, into the matrix relation to calculate values of the unknown currents flowing through the superconductive wires.

Noncontact measurement method of currents on superconductive wires connected in parallel

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.

Method of manufacturing continuous disk winding for high-voltage superconducting transformers

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.

Superconducting wire transposition method and superconducting transformer using the same

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Seoul, South Korea

Kyeong Dal Choi