Abstract: The present invention relates to a combination twist structure of a superconducting cable core. The present invention relates to a new type of a combination twist structure of a superconducting cable core capable of accommodating the thermal contraction of the cable core in the longitudinal direction without having a space for accommodation, thereby capable of reducing an outer diameter of the superconducting cable, and eliminating the use of an additional equipment for forming the space for accommodation. The present invention provides a combination twist structure of a superconducting cable core formed by twisting a plurality of cable cores. The cable cores are combined by repeatedly changing a twist direction of the cable cores, and the contraction of the cable cores in the longitudinal direction is accommodated by untwisting the cable cores.

Abstract: A cryostat of a superconducting cable disclosed herein includes an inner metallic tube filled with liquid nitrogen and extended along the circumference of a core, an outer metallic tube surrounding the circumference of the inner metallic tube at a distance, a cooling vessel of a terminal connecting box connected to the inner metallic tube and filled with liquid nitrogen, an insulation tube surrounding the circumference of the cooling vessel at a distance, an inner bellows tube connecting an end of the outer metallic tube to the cooling vessel, and an outer bellows tube spaced apart from the inner bellows tube and connecting the end of the outer metallic tube to the insulation tube.

Abstract: Provided is a superconducting cable provided with an enhanced cooling ability, the superconducting cable including a core including a superconducting wire rod; an inner sheath surrounding the core; an outer sheath surrounding the inner sheath; a plurality of communication pipes that have both ends communicating with the inner and outer sheaths, and are mounted in the longitudinal direction of the inner and outer sheaths; a plurality of valves that are mounted in the communication pipes; and a plurality of auxiliary cooling systems that are mounted on some of the communication pipes. Cooling fluid supplied from the cooling systems is supplied into the inner sheath through the communication pipes, and is then discharged to the outside through the valves.

Abstract: A substrate for a superconducting wire is made of Ni or Ni alloy, with a ratio of cube texture of 95% or above constant in a width direction of a substrate body, a ratio of low-angle (15 or less) grain boundary of 99% or above regularly distributed in the width direction, a thickness of 40-150 ?m, an average grain size of 100 ?m or less, and a surface roughness of RMS 50 nm or less. A method for fabricating the substrate includes rolling a Ni or Ni-alloy rod with a rectangular section; and thermally treating the rolled rod, the rolling step having a reduction ratio of 5 to 15% at each rolling, the rod being moved between rollers for the rolling process at a linear velocity of 100 m/min or less, the thermally treating process being conducted by heating above a recrystallization temperature with flowing an inert gas including hydrogen gas.

Abstract: Disclosed is a superconductor wire material that configures a conductive layer in a banded state. The superconductor wire material includes a substrate made of metal; at least one buffer layer laminated on the substrate; and a superconductive layer laminated on the buffer layer, wherein, when the superconductor wire material is banded, a banding diameter (D) of the superconductor wire material and a thickness (t) of the substrate have the following relation: {t(D+t)}<0.004. Thus, when the superconductor wire material is banded, it is possible to inhibit a crack from being generated between the buffer layer and the superconductive layer of the superconductor wire material.

Abstract: A method of manufacturing a substrate for a superconducting cable has steps of rolling Hastelloy C-276 or stainless steel with a rolling roll having a surface roughness of 10 nm of less which is a value of a root mean square (RMS), thereby forming a substrate; immersing the rolled substrate in an electrolytic polishing solution to electrolytically polish it; and vapor-depositing a superconducting layer on the electrolytically polished substrate. According to the method, it is possible to reduce the time of electrolytic polishing of the substrate, thereby improving the productivity thereof. In addition, it is possible to make the number of cracks per a unit area and the horizontal level favorable.