JP3283106B2 - Structure of current supply terminal for oxide superconducting conductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a current supply terminal of an oxide superconducting conductor, which is being developed for use in power transport or superconducting magnets.

[0002]

2. Description of the Related Art Conventionally, attempts have been made to manufacture a power cable for power transport, a superconducting magnet or a superconducting power cable for a field winding of a superconducting generator using an oxide superconducting conductor having a high critical temperature. I have. As a conventional example of such a superconducting conductor, as shown in FIG.
A plurality of long oxide-based superconducting tape units 1 (FIG. 1)
A superconducting conductor 3 is known, which is solder-fixed so as to be spirally disposed adjacent to a pipe 2 made of copper or the like around a pipe 2 made of copper or the like. The superconducting tape unit 1 of the superconducting conductor 3 has a sectional structure as shown in FIG.
A plurality of superconducting tapes 6 formed by covering the oxide superconducting core 4 with a soft metal sheath 5 made of silver or the like are laminated and integrated with a metal adhesive such as solder. FIG.
In the superconducting conductor 3 having the structure shown in FIG. 0, liquid nitrogen is allowed to flow as a refrigerant into the center pipe 2 and the surrounding oxide superconducting core 4 is cooled by the liquid nitrogen.

[0003]

Conventionally, in order to manufacture the superconducting conductor 3 having the structure shown in FIG. 10, one superconducting tape unit 1 is constructed by laminating a plurality of superconducting tapes 6,
A method is employed in which a plurality of superconducting tape units 1 are prepared, spirally wound around the outer peripheral surface of the pipe 2, and then fixed by soldering. However, when the superconducting conductor 3 is manufactured by this method, the superconducting tape unit 1 is wound while being directly bent, so that the individual superconducting tapes 6 are easily distorted, and depending on the winding method, the superconducting tape 6 is locally applied to the superconducting tape 6. There is a problem that large distortion is easily added. That is, the oxide superconducting core 4 is made of Bi ₂ S
r ₂ Ca ₂ Cu ₃ O _x , Bi ₂ Sr ₂ Ca ₁ Cu ² O _y , Bi _1.6
Pb _0.4 Sr ₂ Ca ₂ Cu ₃ O _x , Tl ² Ba ² Ca ² Cu
³ O ^y , Tl ² Ba ² Ca ¹ Cu ² O ^y , or Y ₁ Ba ₂
Since it is a ceramic having a composition represented by Cu ₃ O _x or the like, it has brittleness as a ceramic and has a problem that it is very weak against bending force and tensile force. Further, since the sheath 5 made of silver is very soft, there is a problem that the oxide superconducting core 4 is easily damaged by a small external force.

Next, the plurality of superconducting tape units 1
Are sequentially wound around the pipe 2 and fixed one by one by soldering, the solder that has fixed the superconducting tape 6 that has already been soldered is re-melted by the heat when the other superconducting tape 6 is soldered, and The attached superconducting tapes 6 may peel off. Further, when a plurality of superconducting tape units 1 are sequentially fixed by soldering, there is a problem that it is difficult to simultaneously fix the entire superconducting tape unit 1 at an accurate position.

Further, in order to connect a current supply line to the superconducting conductor 3 having the structure shown in FIG. 10, a conductive current supplying ring is fitted at both ends of the superconducting conductor 3, and this is fixed by soldering. However, in this case, if the superconducting tape unit 1 is fixed to the pipe 2 by soldering, the ends of each superconducting tape unit 1 are fixed at both ends of the superconducting conductor 3, so that the operation at the time of solder fixing is performed. In the heat treatment to be performed and the process for cooling to room temperature, due to the difference in the coefficient of thermal expansion between the pipe 2, the superconducting tape unit 1, and the current supply ring, thermal strain acts on these joints, and the superconducting tape unit There is a risk of giving unnecessary distortion. Further, when an external force such as bending is applied when the superconducting conductor 3 is laid, the superconducting conductor 3 tends to be uniformly deformed as a whole, so that strain is added to the superconducting tape units 1. Was.

[0006] The present invention has been made in view of the above circumstances, and does not give a distortion to the superconducting tape unit as compared with the conventional structure in which each superconducting tape unit is fixed to the outer peripheral surface of the tubular body. An object of the present invention is to provide a structure of a current supply terminal of an oxide superconducting conductor which has a structure in which distortion does not easily act on a current supply terminal portion and has less deterioration of superconducting characteristics.

[0007]

According to the first aspect of the present invention, a plurality of spiral grooves are formed on an outer peripheral surface of a tube made of a metal material, and a forward path of a refrigerant is formed inside the tube. A central tubular body, and an oxide superconducting tape unit is loosely inserted into each spiral groove of the central tubular body in a non-fixed state to form a superconducting conductor. At least one end of the superconducting conductor is bent. A flexible current supply lead wire is connected to the superconducting tape unit in the spiral groove, and the superconducting tape unit at the connection portion is movable along with the lead wire along the spiral groove of the central tube.

According to a second aspect of the present invention, in order to solve the above-mentioned problems, a plurality of spiral grooves are formed on an outer peripheral surface of a tube made of a metal material, and a forward passage of a refrigerant is formed therein to form a central tube. An oxide superconducting tape unit is loosely inserted in each spiral groove of the central tubular body in a non-fixed state to form a superconducting conductor, and a conductive tubular member is externally inserted at one end of the superconducting conductor in a longitudinal direction. The cylindrical member is fixed to the superconducting conductor in the spiral groove with a conductive adhesive, and a lead wire for supplying current is connected to the cylindrical member, while the other end of the superconducting conductor in the longitudinal direction is connected to the cylindrical member. The flexible current supply lead wire is branched into a plurality of parts, each branch line is individually connected to the superconducting tape unit, and the superconducting tape unit at the connection part moves along with the branch line along the spiral groove of the central tube. It is made free

According to a third aspect of the present invention, there is provided a superconducting tape unit according to the first or second aspect, wherein an oxide superconducting core is provided inside a tape-shaped sheath made of a conductive metal material. Are formed by laminating a plurality of superconducting tapes and fixing them to each other.

[0010]

The superconducting tape unit is housed in the spiral groove of the central tube, and the superconducting tape unit is spirally wound around the central tube, so that a coolant such as liquid nitrogen flows through the central tube. The superconducting tape unit can be cooled, and the oxide superconducting core of the superconducting tape unit can be placed in a superconducting state and used for energization. Furthermore, 1
Since a plurality of superconducting tape units are provided for each central tube, the current capacity is increased.

Since the superconducting tape unit is loosely inserted into the spiral groove on the outer surface of the central tube with some play in an unfixed state, even if an external force such as bending or torsion acts on the superconducting conductor, the spiral groove is disengaged. superconducting tape unit is independently before the inner
Serial can Rukoto to be slightly deviated position in the longitudinal direction of the helical groove, thereby the external force is constituted hardly acts directly on the superconducting tape unit. Therefore, even when an external force acts on the superconducting conductor, the superconducting tape unit is not damaged, and the superconducting characteristics do not deteriorate. Further, even if an attempt such as bending force or twisting the superconducting power cable acts in such as during laying, since the superconducting tape unit within the spiral groove of the central tube can be moved slightly displaced positions in the longitudinal direction of the spiral groove, Stress and strain do not concentrate on a part of the superconducting tape unit. Furthermore, since the superconducting tape unit is individually connected to a flexible current lead wire and is movable, even if an external force such as bending acts on the superconducting conductor, each superconducting tape unit is placed on the central tube. Can maintain the above-mentioned function of allowing the superconducting tape unit to move, whereby distortion is less likely to act on the superconducting tape unit.

Further, since the mounting of the superconducting tape unit is completed by inserting the superconducting tape unit into the spiral groove of the central tube, the fixed portion such as a soldered portion where the superconducting tapes of the superconducting tape unit are fixed is re-melted. There is no danger.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of the current supply terminal of the oxide superconducting conductor according to the present invention. FIG. 1 (a) shows the structure of one end of the oxide superconducting conductor 9, and FIGS. 1 (b) and (c). ) Shows the structure on the other end side. 2 and 3 are for explaining the internal structure of the oxide superconducting conductor 9. The oxide superconducting conductor 9 is incorporated in a superconducting power cable 10 having a cross-sectional structure shown in FIG. The oxide superconducting conductor 9 has a central tube 11 shown in an enlarged manner in FIGS. 2 and 3. The central tube 11 is formed around the outer periphery of a tube made of a highly conductive metal material such as copper or aluminum. A plurality of spiral grooves 12 (10 in this embodiment) are formed,
The internal space of the tube is defined as a refrigerant outward path 13, and a refrigerant such as liquid nitrogen flows through the refrigerant outward path 13. In the center tube 11 shown in FIG. 3, the spiral pitch of the spiral groove 12 is described as short, but the spiral pitch can be freely increased to several tens cm to several meters.

The inside of the spiral groove 12 of the central tube 9 is
The superconducting tape unit 15 has a spiral groove as shown in FIG.
A gap is provided between the inner wall of the helical groove 12 and the helical groove 12 so as not to protrude from the spiral groove 12 with some play. This is to prevent a mechanical force from acting on the superconducting tape unit 15 when another member is wound around or attached to the outside of the central tube 9.
As shown in FIG. 2, the superconducting tape unit 15 is formed by laminating a plurality of superconducting tapes 16 and fixing them to each other with a metal adhesive such as solder. The superconducting tape 16 is made of Y-Ba-Cu-O, Bi-Pb-
A tape-shaped superconducting core 17 made of an oxide superconductor represented by Sr-Ca-Cu-O, Tl-Ba-Ca-Cu-O, etc., is covered with a sheath 18 made of a noble metal such as silver. Have been.

Here, the superconducting tape unit 15 is not fixed in the spiral groove 12 by solder or the like. This is because, when the superconducting tape unit 15 is fixed in the spiral groove by soldering, the superconducting tape unit 15 is directly affected by an external force such as expansion and contraction transmitted to the central tube 11, and the superconducting tape unit 15 Is deteriorated. That is, when an external force is applied to the central tube 11, even if expansion and contraction of the central tube 11, the superconducting tape unit 15 are independently behave in the longitudinal direction of the central tube 11 position
Since the displacement can be made, the addition of elongation and strain is alleviated, so that the deterioration of the superconducting characteristics is reduced. Further, when the superconducting tape unit 15 is loosely inserted in the spiral groove 12 with a little play, the superconducting tape unit 15 is disengaged from the outer refrigerant return path 28 described later.
Is directly cooled by the refrigerant.

Next, on the outside of the central tube 11, FIG.
As shown in FIG. 3, the inner shielding layer 20, the insulating layer 21, and the outer shielding layer 22 are sequentially covered. Further, outside the outer shielding layer 22, the inner protective pipe 24, the heat insulating layer 25, and the outer A coating layer 29 composed of a protection pipe 26 and an anticorrosion layer 27 is sequentially arranged. It is preferable that the inner protection pipe 24 and the outer protection pipe 26 have a corrugated shape in order to ensure flexibility. The inner shielding layer 20 includes a copper tape 20a wound around the outer surface of the central tube 11, and a semiconductive layer 22b formed by winding a carbon tape or the like outside the copper tape 20a. The shielding layer 22 is composed of a semiconductive layer 22a wound around a carbon tape or the like outside the insulating layer 21 and a copper tape 22b wound outside the semiconductive layer 22a. Is configured.

The insulating layer 21 is made of kraft paper or synthetic paper (polypropylene laminated paper: PPLP) or the like, and is provided to ensure a dielectric strength. Since the electric insulating layer 21 is formed by winding an insulating tape, a refrigerant return path 28 described later on the outside thereof is formed.
The liquid nitrogen of the refrigerant flowing through the semiconductor layer penetrates into this portion via the semiconductive layer 22a, and contributes to the improvement of the insulating properties.

Outside the internal shielding layer 20, a refrigerant return path 28 is defined by the internal shielding layer 20, the separator 23 and the external shielding layer 22. This refrigerant return path 28
Is a flow path through which a refrigerant such as liquid nitrogen flows, and connects the refrigerant return path 28 to the refrigerant outward path 13 inside the central tube 11 at one end of the superconducting power cable 10 and the refrigerant outward path 13 at the other end. And the refrigerant return path 28 are connected to a refrigerant supply source such as liquid nitrogen (not shown), the refrigerant is supplied from the refrigerant supply source to the refrigerant outward path 13, and the refrigerant is returned via the refrigerant return path 28. The refrigerant can be circulated over the entire length.

The separator 23 is wound around the outer shielding layer 22 and is provided for forming a refrigerant outward path 28 between the outer shielding layer 22 and the inner protective pipe 24 outside the outer shielding layer 22. ing. Note that this separator 23
Is from a stainless steel metal wire or CBN,
Ceramics such as Al ₂ O ₃ and partially stabilized zirconia,
Alternatively, polytetrafluoroethylene (Teflon),
A linear body or a strip made of a synthetic resin such as polyethylene or nylon may be used. The inner protective tube 24 and the outer protective tube 26 are made of stainless steel, aluminum, or the like. In this example, the inner protective tube 24 and the outer protective tube 26 are corrugated in order to ensure flexibility, and the anticorrosion layer 2 is formed.
Numeral 7 consists of a resin coating layer for corrosion protection. The inner protective pipe 24 is made of a metal material such as stainless steel having a thickness of about 1.5 to 2 mm, and the heat insulating layer 25 is formed by winding a super insulative or the like and having a thickness of about 10 to 20 mm. It is.

Next, the oxide superconducting cable 1 having the above structure
On one end side of O, the coating around the central tube 11 is omitted, and the central tube 11 protrudes longer than the surrounding coating layer 29, so that the lead wire 30 is formed as shown in FIG. It is connected. In this portion, a tubular member 31 is inserted through one end of the central tubular body 11, and the inner peripheral portion of the tubular member 31 is connected to the outer peripheral portion of the central tubular body 11 and the superconducting tape unit 1.
5 is soldered to the outer surface portion. Therefore, the superconducting tape unit 15 is fixed to the central tube 11 and the cylindrical member 31 at one end thereof so as not to move in the spiral groove 12. A flexible net-like lead wire 30 is wound around the outer peripheral surface of the cylindrical member 31 and soldered.

On the other hand, the oxide superconducting cable 1 having the above structure
On the other end side of O, the coating around the central tube 11 is omitted, and the central tube 11 protrudes longer than the surrounding coating layer 29, and as shown in FIG. Is connected. In this portion, the restraining ring 36 is inserted at a position slightly away from the other end of the central tube 11,
A ring member 37 having a larger diameter than the central tube 11 is arranged on the side of the holding ring 36 and outside the other end of the central tube 11, and a net-like lead wire 38 is provided on the outer periphery of the ring member 37. It is connected.

A number of branch lines 39 corresponding to the number of the superconducting tape units 15 are radially connected to the inner peripheral portion of the ring member 36 at a predetermined interval, and the tip of each branch line 39 is made of a conductor. The blocks 40 are attached, and each block 40 is soldered to the superconducting tape unit 15 at the other end of the central tube 11. As shown in the enlarged view of FIG. 1 (c), a connection fitting 41 is attached to the tip of the net-like branch line 39, and the connection fitting 41 is bolted to the block 40. It is connected. With the above configuration, on the other end side of the oxide superconducting conductor 9, the superconducting tape unit 15 can move slightly along the spiral groove 12 of the central tube 11 together with the block 40 and the branch line 39.

In order to manufacture the superconducting power cable 10, first, one or a plurality of superconducting tapes 16 are laminated, and a necessary portion in the longitudinal direction is fixed with solder to form a superconducting tape unit 15. Then, a plurality of the superconducting tape units 15 are prepared, and
Individually wound along one spiral groove 12. Next, a copper tape 22a and a semiconductive tape are sequentially wound around the center tube body 11 to form an internal shielding layer 20, and an insulating tape is wound thereon to form an insulating layer 21. Subsequently, a semiconductive tape and a copper tape 22b are wrapped thereon to form an outer shielding layer 22, a required number of separators 23 are wrapped around the outer shielding layer 22, and an inner protective pipe 24 is further wrapped over the outer wrapping, and a super insulation is performed. Wrap and heat insulation layer 2
5 and finally an outer protective pipe 26 is covered to form an anticorrosion layer 27, and the oxide superconducting power cable 1 shown in FIG.
0 can be obtained. However, when winding the above-mentioned layers, winding and coating are performed while leaving both ends of the oxide superconducting conductor 9, and the unwound and coated portions are used for connection of a current supply terminal.

After forming each coating layer of the superconducting cable 10, a cylindrical member 31 with a lead wire 30 is fitted into one end of the oxide superconducting conductor 9 and fixed by soldering. Next, a ring member 37 in which a lead wire 38, a branch wire 39, and a block 40 are attached to the other end of the oxide superconducting conductor 9.
And the blocks 40 provided inside the ring member 37 are soldered one by one to the superconducting tape unit 15 in the central tube 11, thereby completing the structure of the terminal portion.

Next, the case where the oxide superconducting power cable 10 having the above structure is used will be described. In the superconducting power cable 10, the superconducting tape unit 1 is cooled by circulating a refrigerant such as liquid nitrogen through the refrigerant outward path 13 and the refrigerant returning path 28.
The superconducting core 17 of No. 5 is transited to the superconducting state and used for energization. In this case, the superconducting core 17 is
Since the cooling can be performed by the refrigerant in the superconductor 3, the stability of the superconducting core 17 can be secured when the electric current is supplied in the superconducting state.

Further, since the outer shielding layer 22, the insulating layer 21, and the inner shielding layer 20 are all formed by wrapping tapes, the liquid nitrogen of the refrigerant flowing through the refrigerant return path 28 on the outer side of the tape is wound around the tape. The superconducting tape units 15 are directly cooled by penetrating into the superconducting tape unit 15 side from the gap. Here, the insulating layer 21 impregnated with the liquid nitrogen has an improved withstand voltage, so that the withstand voltage of the superconducting power cable 10 can be improved. When the superconducting power cable 10 is energized, the superconducting tape unit 15
When the state transitions to the normal conduction state, it is necessary to temporarily release the large power supplied from the power supply source. In such a case, in the superconducting power cable 10 having the above-mentioned structure, the central tube 11 serves as a grounding conductor for ground fault for releasing the current.

Further, since the connection structure as described above is employed, even if a force such as a bending force or a torsion of the laying path acts on the superconducting power cable 10, the superconducting tape unit 15 is kept in the spiral groove 12 within the spiral groove 12. 12 can move slightly along with the block 40 on the other end side of the superconducting cable 10, so that the movement can reduce the force acting on the superconducting tape unit 10. When the superconducting cable 10 is cooled with liquid nitrogen, the superconducting tape unit 1
Although there is a possibility that a stress may act on 5, the stress can be relaxed as in the case described above, and the deterioration phenomenon of the superconductivity can be suppressed. Therefore, it is possible to suppress the application of stress to the superconducting tape unit 15 at the portion where the lead wires 38 are connected, and it is possible to suppress the deterioration of superconducting characteristics. Further, the holding ring 36 is connected to the superconducting tape unit 1 from the spiral groove 12.
5 is prevented from rising.

FIGS. 5 and 6 show a current supply terminal structure according to a second embodiment of the present invention. In this embodiment, a ring-shaped cylindrical member 42 is inserted at one end of a superconducting conductor 9 to form a central tube. 11 and the superconducting tape unit 15..., The lead wire 44 is soldered to the outer peripheral portion of the cylindrical member 42, and the other end of the superconducting conductor 9 is branched from the mesh-like lead wire 45 into the branch wires 46. Are individually soldered directly to the superconducting tape units 15. With such a configuration, the same effect as that of the example described above can be obtained.

FIG. 7 shows an example of a central tube used in the third embodiment of the present invention.
Are provided with a plurality of through-holes 51...
.. Are formed. The through holes 51 are open on the inner peripheral surface of the central tube 50 and the inner bottom surface of the spiral groove 53, and the other through holes 52 are formed on the inner peripheral surface of the central tube 50 and the central tube 50. And an opening on the outer peripheral surface. With the above structure, the refrigerant flowing through the refrigerant outward passage 54 inside the central tube 50 can be guided to the superconducting tape unit 15 through the through holes 51... And 52. 15 can be cooled. At this time, the refrigerant passing through the through holes 51.
, And cools it, and the refrigerant passing through the through-holes 52 oozes out around the superconducting tape unit 15 to cool the superconducting tape unit 15 from the surrounding side.

FIG. 8 shows an example of an oxide superconducting power cable for alternating current. In this superconducting power cable 60, a superconducting tape is wound around the superconducting power cable 10 instead of the copper tape 22b of the outer shielding layer 22 to provide the superconducting shield layer 61. A semiconductive layer 21a formed by winding a semiconductive tape or the like between the insulating layer 21 and the inner shielding layer 20.
And a semiconductive layer 2 formed by winding a semiconductive tape or the like between the insulating layer 21 and the superconducting shield layer 61.
1b is provided. These semiconductive layers 21a, 21b
Is provided, it is possible to electromagnetically shield an alternating magnetic field and the like generated when AC is applied.

The superconducting shield layer 61 has a thickness of 0.1 to 1 μm on a metal tape base such as Hastelloy tape.
A superconducting tape on which a thin superconducting layer of Y-Ba-Cu-O or the like is formed, or a superconducting tape 16 constituting the oxide superconducting conductor 10 described above. It is configured. Here, to form a superconducting layer on the metal tape substrate, a laser vapor deposition method,
A film forming method such as a CVD method (chemical vapor method) and an MBE method (molecular beam epitaxy method) may be performed. Further, a thickness of 5 to 5 is applied on the metal tape substrate by a doctor blade method.
A superconducting tape may be formed by applying a thick film having a thickness of 0 μm and heat-treating it in an oxygen stream to form a superconducting layer in the form of a thick film such as a Y—Ba—Cu—O system.

In this winding, it is preferable to wind the superconducting tape with the metal tape substrate facing outward and the superconducting layer facing inside. Thereby, when the superconducting power cable 60 is used for alternating current, eddy current loss generated at the time of alternating current using the metal tape base material of the normal conducting portion can be suppressed low. Even in the case of performing, the deterioration of the superconducting characteristics of the superconducting layer can be reduced.

As a preferred example of the superconducting shield layer 61, YS is applied to the inner surface of a metal tape base made of a Ni-based alloy such as Hastelloy or a stainless steel tape.
Examples include an intermediate layer made of Z (yttrium-stabilized zirconia), MgO or SrTiO ₃ and a superconducting thin film formed thereon. By adopting this structure, deterioration of the superconductivity can be prevented as described above,
A desired magnetic shielding effect can be obtained.

The superconducting shield layer 61 has a function of repelling the magnetic field generated by the superconducting core 17 by the Meissner effect when the superconducting core 17 is energized. In particular, if an alternating magnetic field acts when AC current is applied, AC loss may occur. Therefore, the superconducting shield layer 61 can prevent the AC loss.

By the way, in the above embodiment has been adopted terminal structure shown in FIG. 1 (b) only the other end portion of the oxide superconductor 9, the both end portions of the oxide superconductor 9 FIG 1 (b)
It goes without saying that the terminal structure described above may be employed. Further, in the above example, the block 40 is attached to each of the superconducting tape units 15. One block 40 may be attached. Further, the branch lines 39 connected to the superconducting tape unit 15 may be bundled together with a margin.
The point is that it is necessary not to apply distortion or unnecessary external force to the superconducting tape unit 15 from the current supply terminal side, and such a configuration is not limited to the above configuration.

"Production Example" Bi: Pb: Sr: Ca: Cu
= 1.8: 0.4: 2.0: 2.2: 3.0 to obtain a composition ratio of Bi ₂ O ₃ , PbO, CuO, SrCO ₃ , CaC
Each powder of O ₃ was blended and calcined at 800 to 840 ° C. for 74 hours four times in the air to obtain a calcined powder. The calcined powder was formed by an isostatic press, inserted into a silver pipe having an outer diameter of 10 mm and a thickness of 2.5 mm, and subjected to cold working until the diameter became 2.4 mm. After that, rolling and 830-84
A heat treatment at 0 ° C. × 50 hours was repeated three times to finally obtain a silver sheath Bi-based tape having a thickness of 0.1 mm and a width of 4.0 mm. Forty-five sheets of this silver sheath Bi-based tape were stacked and fixed by soldering to produce a superconducting tape unit having a width of 4.2 mm and a height of 4.8 mm. This superconducting tape unit was cooled with liquid nitrogen and energized under the condition of an external magnetic field of 0 T.
5A was able to flow.

As a tube, an outer diameter of 40 mm and an inner diameter of 2 mm are used.
Prepare a copper pipe with a length of 0 mm and a length of 10 m.
A central tubular body was formed by forming 10 rectangular spiral grooves (spiral pitch 1 m) having a width of 6 mm and a depth of 6 mm every 6 degrees. The superconducting tape unit was inserted into each of the spiral grooves to obtain a superconducting conductor having a length of 10 m. Thereafter, one end of the superconducting conductor has an inner diameter of 40.5 mm, an outer diameter of 80 mm, and a length of 100 mm.
mm copper tube member was fitted, and the inner periphery of the tube member and the outer surfaces of the superconducting tape unit and the central tube were fixed by soldering.
The outer periphery of the ring member has a 300
A lead wire for 0A (copper braided wire) is attached in advance.

On the other hand, the other end of the superconducting conductor has an outer diameter of 20 mm.
A current supply ring member having a diameter of 0 mm, an inner diameter of 160 mm, and a length of 50 mm is extrapolated, and on this inner peripheral portion, ten branch lines for 300 A made of a braided wire are radially arranged. The base end is fixed to the inner periphery of the ring member at a predetermined interval, and the ends of these branch lines are soldered to the superconducting tape unit inside the spiral groove of the central tube via a copper block. Is attached. The block is a copper block having a width of 3 mm, a length of 30 mm, and a height of 20 mm, and the branch line is bolted. Also, in the portion 50 mm from the other end of the superconducting conductor,
Stainless steel 2 with inner diameter 40.5mm and outer diameter 50mm
A ring having a split structure is fitted to prevent the superconducting tape unit from rising from the spiral groove of the central tube.

One end and the other end of the superconducting conductor having the above-mentioned current supply terminal structure are both ends of a 10 m-long superconducting conductor. Except for this portion, various coatings described below are applied. Construct a superconducting power cable. A copper tape having a thickness of 0.1 mm is wound on the central conductor, and a semiconductive tape containing carbon is further wound to form an inner shielding layer, and a kraft paper is formed thereon to a thickness of 6 mm. This was wound to form an insulating layer. At this time, the thickness of the insulating layer is 7
The structure was designed to withstand 10,000 V of electrical insulation. Then, a semiconductive tape and a copper tape having a thickness of 0.1 mm were wound on the insulating layer.

Next, three wires of 5 mm in diameter made of polytetrafluoroethylene (Teflon) are wound on the copper tape, and the thickness is 5 mm, the outermost diameter is 84 mm, and the innermost diameter is 64.
It was inserted into an inner protective pipe with a corrugated made of stainless steel of 0.2 mm. The inside of this internal protection pipe becomes the refrigerant return path. Further, super insulation is wound on the inner protective pipe so as to have a thickness of 10 mm, and an outer protective pipe made of stainless steel with a corrugate is arranged outside the outer protective pipe. Was obtained.

With respect to this superconducting power cable, liquid nitrogen was circulated using the refrigerant outward path and the refrigerant return path inside the central tube, the whole was cooled to 77 K, and an energization test was performed in an external magnetic field of 0T. As a result, it was possible to flow 2200A having a value close to 10 times the value of 225A obtained in the superconducting tape unit through the superconducting power cable. Therefore, when ten superconducting tape units were collectively formed into a cable, deterioration of superconducting characteristics was hardly observed. Further, when the dielectric strength of the superconducting power cable was measured, it was 80 kV before flowing the liquid nitrogen refrigerant, but was 100 kV after flowing the liquid nitrogen.
Improved. This is because liquid nitrogen used as refrigerant
It is thought to be due to the result of soaking into the insulating layer.

Next, for comparison, a superconducting tape cable was formed by soldering and fixing a superconducting tape unit to a spiral groove of a central tube having the same structure as that described above, and a terminal portion of the superconducting conductor was formed. Fig. 1
A superconducting power cable having a structure using the cylindrical member shown in (a) was manufactured, and an energization experiment was performed. As a result, about 1800A
At normal conduction. From this result, it is considered that the superconducting tape unit is distorted due to heat shrinkage at the stage of cooling from room temperature to the temperature of liquid nitrogen, causing deterioration in characteristics. Further, for comparison, a normal tube having no spiral groove was used in place of the center tube, and ten superconducting tape units were spirally wound therearound, and they were permanently fixed by soldering. A superconducting power cable having a coating layer equivalent to that of was manufactured, but this superconducting power cable is capable of conducting a current of 1000 A,
Significant deterioration of superconductivity was observed. This is probably because the superconducting tape unit was distorted or added due to handling when the superconducting tape unit was wound around the outer periphery of the tube and soldered. Also,
It is considered that when a copper tape or the like is wound around the outside of the superconducting tape unit, the superconducting tape unit is subjected to addition or distortion.

[0043]

As described above, according to the present invention, since the superconducting tape unit is housed in the spiral groove on the outer periphery of the central tube, the superconducting tape unit is formed by flowing a refrigerant such as liquid nitrogen into the tube. It can be cooled and the superconducting core in the superconducting tape unit can be put into a superconducting state and used for energization. Furthermore, since a plurality of superconducting tape units are wound around one central tube, the power capacity can be increased.

The superconducting tape unit has a slight gap between the spiral groove of the central tube and the inner wall of the spiral groove.
Te since it is loosely inserted in a non-fixed state, when an external force due to thermal shrinkage or bending acting upon cooling from room temperature to liquid nitrogen temperature attempts to act on the superconducting tape unit, the superconducting tape unit within the helical groove holding the independence, since it is Rukoto to be slightly deviated position in the longitudinal direction in the spiral groove, less possibility to concentrate the addition of such distortion in the superconducting tape unit, becomes difficult to occur configuration deterioration of superconducting properties ing. In the terminal structure on the other end side of the superconducting conductor, the flexible lead wires are individually connected to the superconducting tape unit so as to maintain the independence of the superconducting tape unit. When external force due to thermal shrinkage or bending that acts during cooling of the superconducting tape unit attempts to act on the superconducting tape unit, there is little risk of concentrating the addition of distortion and the like on the superconducting tape unit,
No deterioration of superconductivity occurs.

Further, in the oxide superconducting power cable of the present invention, since the refrigerant flow path inside the pipe and the refrigerant flow path outside the pipe are provided, the refrigerant passage inside the pipe is formed by the refrigerant passage. If the refrigerant is used as the outward path and the refrigerant flow path outside the tube is used as the return path for the refrigerant, the refrigerant can be circulated, so that the superconducting tape unit can be efficiently cooled and contributes to the stabilization of the superconducting characteristics.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view showing a terminal structure on one end side of a superconducting conductor according to the present invention, and FIG. 1 (b) shows a terminal structure on the other end side of a superconducting conductor according to the present invention. Perspective view, FIG. 1
FIG. 2C is a partially enlarged perspective view of FIG.

FIG. 2 is a sectional view showing a central tube applied to the superconducting cable shown in FIG.

FIG. 3 is a perspective view of the central tube shown in FIG. 1;

FIG. 4 is a cross-sectional view showing a first example of a superconducting power cable to which the terminal structure of the present invention is applied.

FIG. 5 is a second view of the terminal structure on one end side of the superconducting conductor;
It is a perspective view which shows the example of.

FIG. 6 is a second terminal structure on the other end side of the superconducting conductor.
It is a perspective view which shows the example of.

FIG. 7 is a sectional view showing a second example of a superconducting power cable to which the terminal structure of the present invention is applied.

FIG. 8 is a sectional view showing a third example of a superconducting power cable to which the terminal structure of the present invention is applied.

FIG. 9 is a perspective view showing an example of a superconducting tape unit.

FIG. 10 is a sectional view showing an example of a conventional superconducting power cable.

[Explanation of symbols]

9 superconducting conductor, 10 superconducting power cable, 11 central tube , 12 spiral groove, 13 refrigerant outward path, 15 superconducting tape unit, 16 superconducting tape, 17 superconducting core, 18
Sheath, 30 lead wires, 31 cylindrical member, 36
Holding ring, 37 Ring member, 38 Lead wire, 39
Branch line, 40 block, 42 cylinder member, 44
Lead wire, 45 lead wire, 46 branch wire, 50 central tube,

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuomi Kakimoto 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Shigeo Nagaya 20 Kitakanyama, Odaka-cho, Midori-ku, Nagoya-shi, Aichi Prefecture Address No. 1 Chubu Electric Power Co., Inc. Power Technology Research Institute (72) Inventor Naoki Hirano 20-1 Kitakanyama, Odaka-cho, Midori-ku, Nagoya-shi, Aichi No. 1 Power Technology Research Center Chubu Electric Power Co., Ltd. (56) Reference Document JP-A-63-262807 (JP, A) JP-A-6-310188 (JP, A) JP-A-3-116668 (JP, A) JP-A-5-145125 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01R 4/68 H01B 12/02

Claims (3)

(57) [Claims] 1. A central pipe is formed by forming a plurality of spiral grooves on an outer peripheral surface of a pipe made of a metal material and forming an outward path of a refrigerant therein, and an oxide is formed on each spiral groove of the central pipe. The superconducting tape unit is loosely inserted in a non-fixed state to form a superconducting conductor. At least one end of the superconducting conductor, a flexible current supply lead wire is connected to the superconducting tape unit in the spiral groove. And a superconducting tape unit at the connection portion is movable along with a lead wire along a spiral groove of the central tube body. 2. A central pipe is formed by forming a plurality of spiral grooves on an outer peripheral surface of a pipe made of a metal material and forming an outward passage of a refrigerant therein, and an oxide is formed on each spiral groove of the central pipe. The superconducting tape unit is loosely inserted in a non-fixed state to form a superconducting conductor, and a conductive tubular member is extrapolated at one end in the longitudinal direction of the superconducting conductor, and the superconducting conductor in the spiral groove is inserted in the spiral groove. The cylindrical member is connected to a lead wire for supplying current, and the other end of the superconducting conductor in the longitudinal direction has a plurality of flexible lead wires for supplying current. And each branch line is individually connected to the superconducting tape unit in the spiral groove, and the superconducting tape unit of the connection part is made movable along with the branch line along the spiral groove of the central tube. Current supply terminal for oxidized oxide superconductor Structure of. 3. The superconducting tape unit is formed by laminating a plurality of superconducting tapes each having an oxide superconducting core inside a tape-shaped sheath made of a conductive metal material and fixing them together. 3. A method according to claim 1, wherein
The structure of the current supply terminal for an oxide superconducting conductor according to the above.