JP2003077349A - Superconducting conductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting conductor composed as a highly complex structure of a stranded wire formed by winding a stabilizing wire around a superconducting strands, housing the highly complex stranded wire in a conduit of welded structure, enabled to reduce the heat value and improve the superconducting stability without increasing alternating current loss, enduring a big electromagnetic field, suitable for the use of an intense magnetic field and a large current capacity. SOLUTION: A sub conductor 4 is formed by twisting a plurality of pieces of superconducting strands 1 formed by bundling many pieces of superconducting filaments, and twisting a plurality of stabilizing wires 3 around the above. A highly complex strand wire 6 is formed by twisting a plurality of sub conductors 4. At least one piece of wire out of the stabilizing wires 3 is turned into a high resistance metal wire or an insulation wire, and another wires are turned into the superconductor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting conductor formed by twisting a plurality of superconducting wires, and more particularly to a superconducting conductor for improving stability in a superconducting state by reducing AC loss.

[0002]

2. Description of the Related Art In general, in the field of application of superconducting wires, superconducting conductors composed of high-order twisted wires in which a plurality of superconducting element wires are concentrically twisted are widely used in order to increase the capacity of the energizing current. There is. Among them, FIG. 6 shows a cross-sectional structure of a typical superconducting conductor having a large current capacity that can be used even in an environment where electromagnetic force is particularly large.

In this superconducting conductor, as shown in FIG. 6 (A), a plurality of superconducting element wires 1 are concentrically twisted around a reinforcing wire 2, and a stabilizing wire 3 is further twisted around it. As a result, the sub-conductor 4 is formed. The superconducting element wire 1 is configured by bundling several other ultrafine superconducting filaments having a diameter of several μm, and the superconducting filaments are embedded and held in a base material such as copper as a holding material. The stabilizing wire 4 is provided for the purpose of improving the stability when the superconducting state of the superconducting element wire 1 is impaired and suppressing the temperature rise during quenching of the superconducting conductor, and is generally a normal conducting metal. Low resistance copper is applied as a stranded wire.

Next, as shown in FIG. 6 (B), a plurality of the sub-conductors 4 are concentrically twisted around a spiral metal tube 5 forming a cooling channel, whereby a high-order twisted wire 6 is obtained. Of the superconducting conductor 10 (10a).

Further, the outer peripheral side of the high-order twisted wire 6 is covered with a protective tape 7 made of stainless steel or the like and housed in, for example, a square tube-shaped conduit 8, whereby the high-order twisted wire 6 is formed.
A superconducting conductor (conductor-in-conduit conductor) 10 (10b) in which cooling channels are also formed around the periphery of the is formed. The conduit 8 has a tubular structure in which a plate material is bent and joined by a welded portion 9 along the length direction of the high-order twisted wire 6, and the welded wire is usually arranged at the center position of the high-order twisted wire 6. Therefore, the backside welding 9a is partially in contact with the sub-conductor 4.

By the way, although such a superconducting conductor 10 is capable of passing a direct current in a direct current magnetic field without loss, it generates heat due to alternating current loss in a fluctuating magnetic field and causes heat loss. This AC loss is roughly divided into three types: hysteresis loss, coupling loss, and eddy current loss.

First, the hysteresis loss is caused by the superconducting wire 1.
It has the property of being generated in proportion to its diameter in the superconducting filament that constitutes the. Therefore, as described above, an ultrafine superconducting filament having a diameter of several microns is used as the superconducting element wire 1 for alternating current, which operates at a commercial frequency, in order to reduce hysteresis loss.

On the other hand, the coupling loss in the superconducting element wire 1 is generated in the base material such as copper around the superconducting filaments by the coupling current flowing between the superconducting filaments and is proportional to the square of the twist pitch length of the superconducting filaments. At the same time, it has a characteristic inversely proportional to the resistivity of the base material through which the coupling current flows.
Therefore, when the twist pitch length of the superconducting filament is shortened, the coupling loss is reduced, but the twist pitch length is restricted in manufacturing and is substantially proportional to the diameter of the superconducting element wire 1. Therefore, if the diameter of the superconducting element wire 1 is reduced in order to shorten the twist pitch length, the critical current per one of the superconducting element wires 1 becomes low. 1 is required.

This coupling loss is also generated between the superconducting element wires 1 similarly to the mechanism of generation in the superconducting element wires 1 described above. In particular, since the twist pitch length of the final twisted wire as the high-order twisted wire 6 is the longest, a loss proportional to the square of the twist pitch length and inversely proportional to the equivalent resistance between the superconducting element wires 1 occurs. In order to reduce this loss, as a method of increasing the equivalent resistance between the superconducting element wires 1, a method of thinly coating a high resistance layer or an insulating material on the surface of the superconducting element wires 1 is adopted. In order to increase the equivalent resistivity between the superconducting element wires 1, a method of changing the ratio between the superconducting element wires 1 and the surrounding space to reduce the contact between the superconducting element wires 1 is also adopted.

On the other hand, when forming the superconducting conductor 10 by twisting the sub-conductors 4 concentrically, if it is possible to ideally twist the sub-conductors 4 concentrically, the twisting pitch of each sub-conductor 4 When a uniform fluctuating magnetic field is applied to the length of the least common multiple Lp of the length lp, the magnetic flux due to the fluctuating magnetic field received by the area surrounded by the center line of the superconducting conductor 10 and each superconducting element wire 1 is minimum. When the fluctuating magnetic field is integrated over the length of the common multiple Lp, it becomes zero, and the coupling loss between the sub-conductors 4 does not occur. However, in the superconducting conductor 10 having the above-described configuration, since the stabilizing wire rods 4 arranged around the superconducting element wire 1 as the primary twisted wire are all made of copper or the like which is a normal conducting metal, The eddy current that circulates around the stabilizing wire 4 is generated, and this eddy current may increase the AC loss.

Further, an eddy current loss occurs in the stabilizing wire 4 and the conduit 8 described above due to the fluctuating magnetic field. Generally, a low resistance material is used for the stabilizing wire 4 and a high resistance metal is used for the conduit 8. Therefore, the eddy current loss becomes a problem because the eddy current related to the stabilizing metal is used. It is a current loss.

Further, in the welded portion 9 of the conduit 8, the weld backside 9a is raised on the inner surface side of the conduit 8.
The portions locally pressurize the sub-conductor 4 having the stranded wire structure, thereby reducing the contact resistance between the superconducting element wires 1 and thus increasing the coupling current between the superconducting element wires 1. In particular, in the high-order twisted wire 6 that is configured by the n-th power twist of 3, since the final twist pitch is large, a long time constant coupling current is likely to be induced. Such heat generation due to the coupling current between the superconducting wires 1 may result in extremely large AC loss.
As a result, the superconducting conductor 10 (10b) may be quenched.

[0013]

As described above, in the conventional superconducting conductor as a high-order twisted wire, it is generated by winding the stabilizing wire around the superconducting element wire which is the primary twisted wire. The resulting eddy current may increase the AC loss.

In the case of a conductor-in-conduit conductor having a welded structure, the sub-conductor having a stranded wire structure is locally pressed by the weld backside ridge protruding to the inner surface side of the conduit, and the superconducting wire Since the contact resistance is reduced, the coupling current between the superconducting element wires is increased, which may cause an extremely large AC loss, and the superconducting conductor may be quenched.

The present invention has been made in view of the above circumstances, and reduces the eddy current loss generated in the stabilized metal wire and the AC loss caused by the coupling current generated between the superconducting element wires to achieve a superconducting state. It is an object of the present invention to provide a superconducting conductor capable of improving the stability of the.

[0016]

In order to achieve the above object, in the present invention, a plurality of superconducting element wires bundled with a large number of superconducting filaments are twisted together, and a plurality of stabilizing wire rods are twisted around them. A superconducting conductor in which a plurality of sub-conductors are twisted together to form a high-order stranded wire, and at least one of the stabilizing wires is a high-resistance metal wire or an insulated wire, and the others are It is a low resistance metal wire.

As the high resistance wire applied to the above-mentioned stabilizing wire, for example, a wire made of CuNi, stainless steel, nickel-base alloy or titanium alloy, or a chrome-plated copper wire can be used. Further, examples of the wire material of the insulating material include a wire material of formal, tetrafluoroethylene or polyethylene. Furthermore, examples of the low resistance wire include wire materials such as copper, aluminum, silver, and alloys thereof.

When the stabilizing wire is a high resistance wire,
The electric resistance of the eddy current circuit formed around the sub-conductor can be set large, and the eddy current generated can be suppressed small. In addition, when the stabilizing wire is an insulated wire, an eddy current circuit is not formed around the sub-conductor, so that the generation of eddy current can be prevented.

In order to ensure the function of the stabilizing wire rod, it is necessary to prevent the number of high-resistance metal wires or insulating wires from becoming excessive. Less than a few metal or insulated wires, especially 1 to
It is desirable that two wires are arranged and the other wires are low resistance wires.

In the present invention, the superconducting filament is
It is desirable to use a metal-based superconducting wire made of any one of NbTi, Nb ₃ Sn, and Nb ₃ Al, or an oxide high-temperature superconducting wire made of any of Y-based, Bi-based, Tl-based, and Hg-based. By applying filaments made of these materials, the operating temperature can be increased and the specific heat can be increased, so that the superconducting stability can be improved.

The surface of the superconducting element wire is coated with an insulating material such as formal, tetrafluoroethylene or polyethylene, or a high resistance material such as CuNi, chromium, stainless steel, titanium or alloys thereof. It is desirable to do. As described above, by coating the surface of the superconducting element wire with an insulating material such as formal, polyimide-based, or polyamide-based material, it is possible to eliminate the current flowing between the superconducting element wires and reduce the AC loss. When the surface of the superconducting element wire is coated with a high resistance material such as CuNi, chromium, stainless steel, titanium,
AC loss can be reduced by reducing the current flowing between the superconducting wires.

Further, in the present invention, the high-order twisted wire is formed by winding it around a reinforcing wire made of stainless steel, nickel-base alloy, titanium alloy, copper alloy or those having an insulating material on the surface thereof, The reinforcing wire has a polygonal cross section,
Round or oval hollow or solid. That is, by winding the high-order twisted wire around the hollow reinforcing wire, the inside of the reinforcing wire can be used as a cooling channel. Further, when wound around a solid reinforcing wire, it can be used as a so-called compression-molded stranded wire. Then, in each of these cases, it is possible to reduce the AC loss and withstand the electromagnetic force.

Further, in the present invention, the above-mentioned high-order twisted wire is applied as a so-called conductor-in-conduit conductor, which is housed in a conduit made of a high resistance material such as stainless steel, nickel base alloy, titanium alloy or the like. in this way,
By accommodating the high-order stranded wire in a conduit, it can be configured to withstand a large electromagnetic force, and is suitable as a superconducting conductor for high magnetic field and large current capacity.

Further, according to the present invention, in the case where the conduit has a joint structure in which welding is performed along the length direction of the high-order twisted wire, the welded wire is located at a radial position deviated from the center line of the high-order twisted wire. To place. Thus, by arranging the welded portion of the conduit so as to be displaced from the center of the conductor, it is possible to avoid contact between the protruding portion such as the backside of the welding and the superconducting element wire. This makes it possible to locally pressurize the superconducting wires, locally lower the contact resistance, prevent the twisted wires from being disturbed, etc., and effectively prevent the occurrence of coupling loss between the superconducting wires due to these. In addition, the superconducting stability can be improved.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a superconducting conductor according to the present invention will be described below with reference to FIGS. In the following embodiments, the same components as those in the conventional example will be described using the same reference numerals as those in FIG.

First Embodiment (FIGS. 1 and 2) In the present embodiment, the superconducting conductor formed as a high-order twisted wire is housed in a conduit so that the superconducting conductor (conductor
In-conduit conductor). FIG. 1 is a cross-sectional view showing the overall configuration, and FIG. 2 is an enlarged cross-sectional view showing the component configuration.

First, the superconducting conductor 10 (10a) configured as the high-order twisted wire 6 will be described with reference to FIG. Figure 2
FIG. 2A is an enlarged cross-sectional view of the sub-conductor 4 forming the high-order twisted wire 6, and FIG. 2B is a further enlarged cross-sectional view of the superconducting element wire 1 forming the sub-conductor 4. Is a figure,
FIG. 2C is a sectional view showing the superconducting filament 11 forming the superconducting element wire 1 in a further enlarged manner.

As shown in FIG. 2C, the superconducting filament 11 is embedded and held in a base material 12 made of copper as a holding material, and a CuNi coating 13 is applied to the outside thereof. As shown in FIG. 2B, a large number of such superconducting filaments 11 are bundled around a copper wire 14 which is a normal conductor to form a stranded wire, and a CuNi coating 15 is applied to the outer peripheral surface thereof, for example. A superconducting wire 1 is configured. In addition to CuNi, a high resistance material such as chromium, stainless steel, titanium, or an alloy thereof, or an insulating material such as formal, tetrafluoroethylene, or polyethylene may be applied to the coatings 13 and 15.

Then, as shown in FIG. 2A, a plurality of superconducting wires 1 having the above-mentioned structure are concentrically twisted around a reinforcing wire 2 made of copper and having a diameter substantially the same as those of the superconducting wires 1. The sub-conductor 4 is formed by twisting a plurality of stabilizing wire rods 3 around it. This sub conductor 4
Among the stabilizing wire rods 3 of, for example, 2 which are symmetrically arranged
The stabilizing wire 3a is a high resistance metal wire or an insulating wire, and the other stabilizing wire 3 is a low resistance metal wire, for example, a copper wire.

As the high resistance wire of the stabilizing wire 3a, for example, a wire made of CuNi, stainless steel, nickel base alloy or titanium alloy, or a chrome-plated copper wire is used. When the wire material is an insulating material, a wire material such as formal, tetrafluoroethylene, or polyethylene is applied. Further, copper, aluminum, silver or alloys thereof are applied as the low resistance wire.

As shown in FIG. 1, a plurality of such sub-conductors 4 are concentrically twisted around a hollow body having a circular cross section which constitutes a cooling channel, for example, a spiral metal tube 5 to thereby increase the height. A superconducting conductor 10 (10a) as the next twisted wire 6 is configured. Further, the outer peripheral side of the high-order twisted wire 6 is covered with a protective tape 7 made of stainless steel or the like and housed in a rectangular tube-shaped conduit 8, whereby cooling channels are also formed around the high-order twisted wire 6 and the like. Superconducting conductor (conductor-in-conduit conductor) 10
(10b) is configured. The conduit 8 has a tubular structure in which a plate material made of a high resistance material such as stainless steel, a nickel-base alloy, or a titanium alloy is bent and joined by a welded portion 9 along the length direction of the high-order twisted wire 6. The welding line is arranged radially away from the center position of the high-order stranded wire 6 so that the welding back wave 9a does not partially contact the sub-conductor 4.

The superconducting conductor of the present embodiment having the above structure, that is, the superconducting conductor 10 (1 as the high-order twisted wire 6
0a) and the high-order twisted wire 6 housed in a conduit 8 (conductor-in-conduit conductor) 10 (1
According to 0b), by using, for example, two stabilizing wire rods 3a among the stabilizing wire rods 3 twisted around the superconductor element wire 2 as a high resistance metal wire or an insulated wire, It is possible to suppress the eddy current generated by setting the electric resistance of the eddy current circuit formed around it large,
Alternatively, it is possible to prevent the generation of the eddy current without forming an eddy current circuit around the sub conductor 4.

That is, when only a high-purity, low-resistance copper wire is used as the stabilizing wire 3 as in the conventional case, it circulates around the sub-conductor 4 which is a primary stranded wire via the copper wire. The resistance value of the circuit becomes small, and the eddy current loss generated here becomes very large. However, in this embodiment, since the stabilizing wire 3a as the high resistance wire or the insulating wire is arranged, the primary twisted wire is formed. It is possible to remarkably increase the resistance of the circuit that circulates around the sub-conductor 4, and it is possible to suppress the generation of eddy currents. For example, the resistivity of copper is 1.5 × 10
^Although it is about ⁻¹⁰ Ωm, when CuNi, stainless steel, or the like is used as the high resistance wire, the resistivity is 1000 times or more higher, so that the generated eddy current is at a level that can be ignored. Therefore, AC loss is extremely small, heat generation is eliminated, and superconducting stability is improved.

In this embodiment, the two stabilizing wire rods 3a are high resistance metal wires or insulated wires, but the number can be set appropriately for the stabilizing wire rods 3.

Further, in this embodiment, the superconducting filament 11 is made of a metal superconducting wire made of any one of NbTi, Nb ₃ Sn and Nb ₃ Al, or a Y-based and Bi-based superconducting wire.
Since the oxide high-temperature superconducting wire made of any one of the series, the Tl series, and the Hg series is used, the operating temperature can be increased and the specific heat can be increased, and the stabilizing wire 3a as a high resistance wire or an insulating wire is arranged. In addition, the stability of superconductivity can be further improved.

The surface of the superconducting element wire 1 is coated with an insulating material such as formal, tetrafluoroethylene or polyethylene, or a high resistance material 15 such as CuNi, chromium, stainless steel, titanium or an alloy thereof. Therefore, it is possible to eliminate or reduce the current flowing between the superconducting element wires 1 and reduce the AC loss. Therefore, the superconducting stability can be further improved together with the arrangement of the stabilizing wire 3a as the high resistance wire or the insulated wire.

Further, the high-order twisted wire 6 is made of stainless steel,
By wrapping around a hollow reinforcing wire 5 having a circular cross section, which is made of a nickel-based alloy, a titanium alloy, a copper alloy, or an insulating material on the surface thereof, the inside of the reinforcing wire 5 serves as a cooling channel. It can be used, and the AC loss can be reduced and the structure can withstand electromagnetic force. Therefore, the superconducting stability can be further improved together with the arrangement of the stabilizing wire 3a as the high resistance wire or the insulated wire.

Further, since the high-order twisted wire 6 is housed in the conduit 8 made of a high resistance material, a structure capable of withstanding a large electromagnetic force can be obtained, which is suitable as a superconducting conductor for a high magnetic field and a large current capacity. Becomes In this case, in particular, in the present embodiment, the conduit 8 has a joint structure in which welding is performed along the length direction of the high-order twisted wire 6, and the welded wire is placed at a radial position deviated from the center line of the high-order twisted wire. By arranging it, it becomes possible to avoid that the protruding portion of the weld back wave 9a of the welded portion 9 contacts the superconducting element wire 1. Therefore, it is possible to prevent the local pressurization of the superconducting element wires 1, the reduction of the local contact resistance, and the turbulence of the twisted wires, and the occurrence of the coupling loss between the superconducting element wires due to these. It can be effectively prevented and the superconducting stability can be improved. Particularly, due to the synergistic effect with the configuration in which the stabilizing wire 3a as a high resistance wire or an insulated wire is arranged,
A superconducting conductor with extremely high superconducting stability can be obtained.

FIG. 3 shows a case where the conduit 8 is integrally formed without a welded portion. The other configurations are the same as above. Even when the conduit 8 having such a configuration is applied, it does not cause local pressurization of the superconducting element wire 1, local contact resistance, or disorder of the twisted wire, and thus has high resistance. A superconducting conductor having extremely high superconducting stability can be obtained by arranging the stabilizing wire 3a as a wire or an insulated wire.

Second Embodiment (FIGS. 4 and 5) This embodiment relates to a case where the winding structure of the high-order twisted wire 6 is modified. FIG. 4 is a sectional view showing a superconducting conductor 10a as the high-order twisted wire 6, and FIG. 5 is a superconducting conductor 10b in which the high-order twisted wire 6 is housed in a conduit 8.
FIG. Since the other configurations are the same as those in the first embodiment, the same reference numerals as those in FIGS. 1 to 3 are given to FIGS. 4 and 5 and the description thereof is omitted.

In this embodiment, as shown in FIG. 4, the reinforcing wire 16 around which the high-order twisted wire 6 is wound has a solid structure made of a plate having a rectangular cross section. This reinforcing wire 1
6 is made of stainless steel, nickel-base alloy, titanium alloy, copper alloy, or their surface coated with an insulating material 17, like the metal tube 5 as the reinforcing wire rod in the first embodiment. . This reinforcing wire 16
A plurality of sub-conductors 4 are wound around the to form a superconducting conductor 10a as a high-order twisted wire 6. Also in the superconducting conductor 10a of the present embodiment, at least one of the stabilizing wire rods 3 arranged around the high-order twisted wire 6 is a high resistance metal wire or an insulated wire.

Then, as shown in FIG. 5, such a high-order twisted wire 6 is housed in a conduit 8 in a two-stage structure, for example. As a result, a superconducting conductor (conductor-in-conduit conductor) 10 (10b) in which the high-order twisted wire 6 is housed in the conduit 8 is formed. The conduit 8 is, for example, a welded structure, and the backside wave 9a of the welded portion 9 is arranged at a position deviated from the central portion of the high-order twisted wire 6.

According to the second embodiment having such a configuration,
It can be used as a so-called compression-molded stranded wire having no cooling channel at the center of the high-order stranded wire 6. In this case as well, by using at least one of the stabilizing wire rods 3 as a high-resistance metal wire or an insulating wire, it is possible to reduce the AC loss and the electromagnetic force as in the first embodiment. It can also be configured to withstand. Further, by arranging the weld backside wave 9a of the welded portion 9 at a position deviated from the central portion of the high-order twisted wire 6, local pressurization of the superconducting element wire 1 or local contact resistance may be reduced. It is possible to prevent the twisted wires from being disturbed, effectively prevent the occurrence of coupling loss between the superconducting element wires due to these, and improve the superconducting stability.

Other Embodiments In the above first and second embodiments, the reinforcing wire rod around which the high-order twisted wire 6 is wound is the metal tube 5 or the plate-like reinforcing wire rod 16, but the present invention is not limited to this. Without being limited to this, various shapes of reinforcing wire can be applied. That is, the cross section may be hollow, polygonal, circular or elliptical or solid.

[0045]

As described above, according to the present invention, a superconducting conductor configured as a high-order twisted wire around which a stabilizing wire is wound around a superconducting element wire, and a conduit having a welded structure of the high-order twisted wire. In a superconducting conductor of the type housed in, the amount of heat generation can be reduced without increasing AC loss.
And the superconducting stability can be improved. Further, it can withstand a large electromagnetic force, and can be a superconducting conductor suitable for a high magnetic field and a large current capacity.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing a superconducting conductor according to a first embodiment of the present invention.

2 (A), (B), and (C) are enlarged cross-sectional views showing components of the first embodiment of the present invention.

FIG. 3 is an overall cross-sectional view showing another configuration example of the superconducting conductor according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a superconducting conductor as a high-order twisted wire according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a conduit-containing superconducting conductor according to a second embodiment of the present invention.

6A and 6B are explanatory views showing a conventional example.

[Explanation of symbols]

1 Superconducting wire 2 reinforcement line 3 Stabilizing wire 4 sub conductors 5 Metal tube (reinforcing wire) 6 Higher stranded wire 7 protective tape 8 conduits 9 welds 9a Welding back wave 10 (10a, 10b) Superconducting conductor 11 Superconducting filament 12 Base material 13, 15, 17 coating 14 Copper wire 16 Reinforcing wire

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mamoru Shimada             2-4 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Toshiba Keihin Office (72) Inventor Shigeo Nagaya             20 Kitakanzan, Otakamachi, Midori-ku, Nagoya-shi, Aichi             No. 1 Chubu Electric Power Co., Inc. (72) Inventor Naoki Hirano             20 Kitakanzan, Otakamachi, Midori-ku, Nagoya-shi, Aichi             No. 1 Chubu Electric Power Co., Inc. F-term (reference) 5G321 AA11 BA01 CA16 CA42 CA48                       DA06

Claims (9)

[Claims] 1. A plurality of superconducting element wires in which a large number of superconducting filaments are bundled are twisted together, and a plurality of stabilizing wires are twisted around them to form a sub-conductor, and a plurality of the sub-conductors are twisted together to form a high conductor. A superconducting conductor configured as a next twisted wire, wherein at least one of the stabilizing wire materials is a high resistance metal wire or an insulating wire, and the other is a low resistance metal wire. 2. The superconducting conductor according to claim 1, wherein the high resistance wire is a wire made of CuNi, stainless steel, a nickel-base alloy or a titanium alloy, or a chrome-plated copper wire. 3. The superconducting conductor according to claim 1, wherein the insulated wire is a wire made of formal, tetrafluoroethylene or polyethylene. 4. The low resistance wire is a wire made of copper, aluminum, silver or an alloy thereof.
The superconducting conductor as described in any one of 1 above. 5. The superconducting filament is NbTi,
5. A metal-based superconducting wire made of either Nb ₃ Sn or Nb ₃ Al, or a high-temperature oxide superconducting wire made of any of Y-based, Bi-based, Tl-based, and Hg-based superconducting wire. The superconducting conductor described in. 6. The surface of the superconducting wire is formal,
The superconducting conductor according to any one of claims 1 to 5, which is coated with an insulating material such as ethylene tetrafluoride or polyethylene, or a high resistance material such as CuNi, chromium, stainless steel, titanium or an alloy thereof. 7. The high-strand wire is wound around a reinforcing wire made of stainless steel, nickel-base alloy, titanium alloy, copper alloy, or those whose surface is provided with an insulating material, and is used for the reinforcement. The superconducting conductor according to any one of claims 1 to 6, wherein the wire is a hollow or solid wire having a polygonal, circular or elliptical cross section. 8. A superconducting conductor, characterized in that the high-order twisted wire according to any one of claims 1 to 7 is housed in a conduit made of a high resistance material such as stainless steel, nickel-base alloy, titanium alloy or the like. . 9. The conduit has a joint structure in which welding is performed along the length direction of the high-order stranded wire, and the weld line is located at a radial position deviated from the center line of the high-order stranded wire. The superconducting conductor according to claim 8, which is arranged.