JP2017073387A - Connection structure of superconducting cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate construction work by corresponding suitably to telescopic motion of a superconducting cable due to temperature change.SOLUTION: A connection structure 20 for connecting first and second superconducting cables 10A, 10B, includes: a connection cable 30 having conductor layers 31, 33; and more than one connection terminals 40A, 40B for holding the superconductive conductor layers 130, 150 of the first or second superconducting cable and the conductor layer of the connection cable. The superconductive conductor layer of the first superconducting cable and the conductor layer of the connection cable at one end are connected by one connection terminal, and the superconductive conductor layer of the second superconducting cable and the conductor layer of the connection cable at the other end are connected by the other connection terminal.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a connection structure for a superconducting cable.

A superconducting cable includes a cable core in which a superconducting conductor layer, an electrical insulating layer, and the like are laminated around a former, and a heat insulating pipe having a vacuum double pipe structure that accommodates the cable core. A cryogenic liquid refrigerant (for example, liquid nitrogen) is circulated to cool the air.
As an intermediate connecting part for connecting such a superconducting cable, the connecting ends of the superconducting cables to be connected are butted together, a steel core is inserted into the center of each former, and each former is connected to one end of a metal compression sleeve. And is connected to the other end by compression. Furthermore, each former and the superconducting conductor layer are accommodated inside the metal cylinder, and electrical connection is performed by pouring solder into the metal cylinder (see, for example, Patent Document 1).

  As another superconducting cable connection structure, the connecting end of the superconducting cable to be connected is stepped for each layer and abutted with each other, and the gap formed by the abutting of the former having a wedge-shaped tip is welded with solder or the like A superconducting conductor layer was connected from above by being buried with metal, and the entire inner connecting portion was covered with a reinforcing insulating layer (see, for example, Patent Document 2).

JP 2001-6837 A Japanese Patent No. 5137539

However, since both Patent Documents 1 and 2 have a structure in which each layer is connected in a state in which the connection ends of the superconducting cables are abutted with each other, they restrain each other when expansion and contraction occurs due to a temperature change of the superconducting cable. Therefore, there has been a problem that a compressive load or a tensile load is applied to the cable, and the response to the influence is not sufficient.
In both Patent Documents 1 and 2, welding is essential for connecting the formers, the connection work is complicated, and the work load is large.

  An object of the present invention is to provide an intermediate connection portion of a superconducting cable that suppresses the influence of expansion and contraction due to temperature change of the superconducting cable and is easy to perform construction work.

  The invention according to claim 1 is a connection structure for connecting the first and second superconducting cables, the connecting cable having a conductor layer, the superconducting conductor layer of the first or second superconducting cable, and the connection. At least two connection terminals that hold a conductor layer of the cable for connection, and the superconducting conductor layer of the first superconducting cable and the conductor layer at one end of the connection cable are connected by one of the connection terminals. The superconducting conductor layer of the second superconducting cable and the conductor layer at the other end of the connection cable are connected by the other connecting terminal.

  According to a second aspect of the present invention, in the superconducting cable connection structure according to the first aspect, the superconducting cable includes a plurality of superconducting conductor layers concentrically.

  According to a third aspect of the present invention, in the superconducting cable connection structure according to the second aspect, a plurality of the connection terminals are provided, and the superconducting conductor layer of the first superconducting cable is stripped by any of the connection terminals. The exposed portion and the portion exposed by stepping of the conductor layer at one end of the connection cable are connected, and any one of the connection terminals causes the step of the superconducting conductor layer of the second superconducting cable. A portion exposed by peeling is connected to a portion exposed by step peeling of the conductor layer at the other end of the connection cable.

  The invention according to claim 4 is the superconducting cable connection structure according to any one of claims 1 to 3, wherein the connecting cable is smaller in diameter than the first and second superconducting cables. Features.

  The invention according to claim 5 is the superconducting cable connection structure according to any one of claims 1 to 4, wherein the connecting cable is a superconducting cable, and the conductor layer is a superconducting conductor layer. And

  According to a sixth aspect of the present invention, in the superconducting cable connection structure according to any one of the first to fifth aspects, the connection ends of the first and second superconducting cables and the connecting cable are stored. An insulating container is provided, and the connecting cable is stored in a bent state or a spiral state in the insulating container.

  The invention according to claim 7 is the superconducting cable connection structure according to any one of claims 1 to 6, wherein the connection terminal is connected to the superconducting conductor layer of the first or second superconducting cable. The conductor layer of the cable is sandwiched between a plurality of members, and is caulked to be conductive.

  The invention according to claim 8 is the connection structure of the superconducting cable according to any one of claims 1 to 6, wherein the connection terminal is connected to the superconducting conductor layer of the first or second superconducting cable. It is characterized in that the conductor layer of the cable is made conductive by insertion.

  The invention described in claim 9 is the superconducting cable connection structure according to any one of claims 1 to 8, wherein the former of the first superconducting cable and the former of the second superconducting cable are connected. It is a state.

In the above invention, since the superconducting conductor layer of the first superconducting cable and the superconducting conductor layer of the second superconducting cable are conductively connected by the connecting cable via the connection terminal, the expansion and contraction due to the temperature change of each superconducting cable. When this occurs, the connecting cable allows this, and the influence on each superconducting cable can be reduced.
In addition, since the superconducting conductor layer of each superconducting cable and the conductor layer of the connecting cable are connected by the holding connection terminals, welding work is not required, work load can be reduced, and construction work can be facilitated. .

It is a perspective view which shows the structure of the one end part of a superconducting cable. It is explanatory drawing which shows the layer structure of a superconducting wire. It is sectional drawing of the intermediate connection part of the superconducting cable which is 1st embodiment. It is a perspective view which shows the structure of the one end part of the cable for connection. It is the figure which looked at the 1st connecting terminal from the cable direction. It is sectional drawing of the intermediate connection part of the superconducting cable which is 2nd embodiment. It is the figure which looked at the 1st connecting terminal from the cable direction. It is the figure which looked at the other example of the connection terminal from the cable direction. It is sectional drawing of the intermediate connection part of the superconducting cable which is 3rd embodiment. It is sectional drawing of the intermediate connection part of the superconducting cable which is 4th embodiment. It is the figure which looked at the 1st connecting terminal which can connect two connecting cables from the cable direction. It is the figure which looked at the 1st connecting terminal which can connect three connecting cables from the cable direction. It is sectional drawing of the intermediate connection part of the superconducting cable which is 5th embodiment. It is sectional drawing of the intermediate | middle connection part of the superconducting cable which shows the example which loosened the cable for connection in 5th embodiment. It is sectional drawing which shows the assembly process of the intermediate connection part of the superconducting cable which is 6th embodiment. It is sectional drawing which shows the assembly process of the intermediate connection part of the superconducting cable following FIG. It is sectional drawing which shows the assembly process of the intermediate connection part of the superconducting cable following FIG.

[First embodiment]
Hereinafter, a preferred first embodiment for carrying out the present invention will be described with reference to the drawings. As this embodiment, the intermediate connection part 20 as a connection structure for connecting the first superconducting cable 10A and the second superconducting cable 10B will be described.
However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[Superconducting cable]
FIG. 1 is a perspective view of the first superconducting cable 10 </ b> A and the second superconducting cable 10 </ b> B in a state where stepping has been performed on the connection end portion. Each of the superconducting cables 10A and 10B is connected by an intermediate connecting portion 20 to be described later in a state where stripping is performed as shown in FIG.
In addition, since the first superconducting cable 10A and the second superconducting cable 10B have the same structure, the same reference numerals are given to the respective components, and duplicate descriptions are omitted.

  The first and second superconducting cables 10 </ b> A and 10 </ b> B are single-core superconducting cables in which a single cable core 11 is housed in a heat insulating tube 12. In the cable core 11, each layer is formed in the order of the former 140, the first superconducting conductor layer 130, the electric insulating layer 113, the second superconducting conductor layer 150, the electric insulating layer 115, and the protective layer 116 from the center to the outside. Is formed.

The former 140 is a member for forming the cable core 11 and is configured by twisting conductive materials such as copper, for example. A fault current flowing in the first superconducting conductor layer 130 is shunted to the former 140 when a short-circuit fault occurs.
The former 140 has a hollow interior, and a liquid refrigerant (for example, liquid nitrogen) is formed in the hollow portion in order to cool the former 140 and the first and second superconducting conductor layers 130 and 150. ) Is supplied. The liquid refrigerant is the same as that supplied around the cable core 11 in the heat insulating pipe 12 described later.
In addition, the former 140 may be solid inside, and it is not essential that the former 140 is hollow, but merely an example.

The first superconducting conductor layer 130 is formed by winding a plurality of superconducting wires 100 in a spiral shape on the former 140 via the carbon paper 112.
The second superconducting conductor layer 150 is formed by winding a plurality of superconducting wires 100 on the inner electrical insulating layer 113 in a spiral manner in a direction opposite to that of the first superconducting conductor layer 130, for example. .
Current is transmitted to the first superconducting conductor layer 130 and the second superconducting conductor layer 150 in opposite directions.

For example, as shown in FIG. 2, the superconducting wire 100 constituting the first and second superconducting conductor layers 130 and 150 has an intermediate layer 2 on one main surface (one surface in the thickness direction) of the substrate 1. 1 is a tape-shaped superconducting wire including a laminated body in which a superconducting layer 3 and a protective layer 4 are laminated in order, and a copper stabilizing layer 5 covering the periphery of the laminated body.
The superconductor constituting the superconducting layer 3 is represented by an RE-based superconductor (RE: rare earth element) that exhibits superconductivity at a liquid nitrogen temperature or higher, for example, the chemical formula YBa ₂ Cu ₃ O _7-y (y is an oxygen non-stoichiometric amount). The yttrium-based superconductor (hereinafter referred to as Y-based superconductor) is representative.
Note that the thickness (the vertical dimension in FIG. 2) of the superconducting wire 100 is much thinner than the width (the horizontal dimension in FIG. 2). However, in FIG. In FIG.

  The electrical insulating layers 113 and 115 are made of insulating paper, for example, insulating paper, semi-synthetic paper in which insulating paper and polypropylene film are joined, polymer nonwoven fabric tape, and the like, and the first superconducting conductor layer 130 or the second superconducting layer. It is formed in a laminated state by winding on the conductor layer 150.

  The protective layer 116 is made of, for example, insulating paper, polymer nonwoven fabric, and the like, and is formed by winding on the electrical insulating layer 115.

The heat insulating tube 12 is a double member that includes the heat insulating inner tube 121 that accommodates the cable core 11 and is filled with a refrigerant (for example, liquid nitrogen), and the heat insulating outer tube 122 that is disposed so as to cover the outer periphery of the heat insulating inner tube 121. It has a tube structure.
The heat insulating inner tube 121 and the heat insulating outer tube 122 are, for example, stainless corrugated tubes (corrugated tubes). Between the heat insulation inner pipe 121 and the heat insulation outer pipe 122, for example, a multilayer heat insulation layer (super insulation) 123 composed of a laminated body of polyethylene film vapor-deposited aluminum is interposed and kept in a vacuum state. Moreover, the outer periphery of the heat insulation outer tube | pipe 122 is coat | covered with anticorrosion layers 124, such as polyvinyl chloride (PVC) and polyethylene.

[Intermediate connection of superconducting cable: Overview]
FIG. 3 is a cross-sectional view of the intermediate connection portion 20 of the superconducting cable.
As shown in the figure, the intermediate connection portion 20 includes a cylindrical heat insulating container 21 that houses the connection ends of the first and second superconducting cables 10A and 10B inside, and the first and second inner portions of the heat insulating container 21 inside the heat insulating container 21. A connection cable 30 for connecting the two superconducting cables 10A, 10B, and first and second connection terminals 40A, 40B for connecting the first or second superconducting cables 10A, 10B and the connection cable 30. ing.

[Intermediate connection: insulated container]
In this heat insulating container 21, the ends of the heat insulating pipes 12 of the first and second superconducting cables 10A and 10B are individually connected to both ends in the center line direction by welding. Then, a liquid refrigerant (for example, liquid nitrogen) for cooling the cable core 11 supplied to the inside of the heat insulation inner pipe 121 of each superconducting cable 10A, 10B is supplied to the heat insulation container 21 (strictly, the inside of the inner pipe 211 described later). ) Is also supplied.

The heat insulating container 21 has a double wall surface structure of a cylindrical inner tube 211 and an outer tube 212.
As shown in FIG. 3, the inner tube 211 is welded with a side plate 213 that closes one end and the other end of the cable in the longitudinal direction (hereinafter referred to as the cable direction). The side plate 213 is formed with a circular hole in the center, and the edge around the circular hole is welded to the connection end of the heat insulating inner tube 121 of the first or second superconducting cable 10A, 10B. Thereby, the internal sealed space formed by the inner tube 211 and the side plates 213 on both sides communicates with the interior of the heat insulating inner tube 121, and the liquid refrigerant is circulated in the sealed space.

As shown in FIG. 3, the outer tube 212 is welded with a side plate 214 that closes one end and the other end in the cable direction. The side plate 214 has a circular hole at the center, and the edge around the circular hole is welded to the connection end of the heat insulating outer tube 122 of the first or second superconducting cable 10A, 10B. Thereby, the clearance space formed by the inner tube 211, the outer tube 212, the side plate 213, and the side plate 214 communicates with the clearance space between the heat insulating inner tube 121 and the heat insulating outer tube 122, and the clearance space is collectively evacuated. be able to.
Therefore, the inside of the inner tube 211 of the heat insulating container 21 can be insulated.

[Connection cable]
FIG. 4 is a perspective view showing a state where one end of the connection cable 30 is stripped. FIG. 4 shows only one end of the connection cable 30, but the other end is also stripped in the same manner.
The connection cable 30 is formed in the order of the first conductor layer 31, the electrical insulation layer 32, the second conductor layer 33, the electrical insulation layer 34, and the protective layer 35 from the center to the outside. .
The 1st and 2nd conductor layers 31 and 33 are comprised by twisting strands, such as copper, for example.
The electrical insulating layers 32 and 34 are made of, for example, a crosslinked polyethylene insulator.
The protective layer 35 is made of, for example, a vinyl sheath.

The connection cable 30 is arranged in such a manner that both ends thereof are stripped and one end thereof is disposed in the opposite direction next to the first superconducting cable 10A and the other end is disposed in the opposite direction next to the second superconducting cable 10B. Placed in.
The connection cable 30 has a smaller diameter than the superconducting cables 10A and 10B, can be easily bent, and has a length sufficiently longer than the entire length of the heat insulating container 21.
The connection cable 30 is spirally wound between one end and the other end inside the heat insulating container 21. Therefore, even when the superconducting cables 10A and 10B expand and contract due to temperature changes, the connection cable 30 can expand and contract.
Note that the connection cable 30 is not limited to a spiral shape, and may be arranged in a bent state, for example, in a U shape.

In the heat insulating container 21, the first conductor layer 31 and the second conductor layer 33 which are stripped at one end of the connection cable 30 are respectively the second superconductor which is stripped from the first superconducting cable 10A. The conductor layer 150 and the first superconducting conductor layer 130 are arranged so that the positions in the cable direction coincide with each other.
In addition, the first conductor layer 31 and the second conductor layer 33 that are stripped at the other end of the connection cable 30 are respectively separated from the second superconducting conductor layer 150 that is stripped from the second superconducting cable 10B. And the first superconducting conductor layer 130 are arranged so that their positions in the cable direction coincide with each other.
In FIG. 3, the electrical insulating layers 32 and 34 exposed by the stepping of the connection cable 30 and the electric insulating layers 113 and 115 exposed by the stepping of the first and second superconducting cables 10A and 10B are shown. Is omitted.

[Connecting terminal]
One of the two first connection terminals 40A has a first conductor layer 31 at one end of the connection cable 30 and a second superconducting conductor layer of the first superconducting cable 10A, the positions of which coincide with each other in the cable direction. 150 is sandwiched between a plurality of members, and staking is conducted between them.
The other first connection terminal 40A has the first conductor layer 31 at the other end of the connection cable 30 and the second superconducting conductor layer 150 of the second superconducting cable 10B, the positions of which coincide with each other in the cable direction. Are sandwiched between a plurality of members, and are connected by caulking.
When sandwiching and caulking with a plurality of members, sleeves 311 made of a cylindrical good conductor (for example, copper) are attached to the outer periphery of the first conductor layer 31 at both ends of the connection cable 30. For example, solder is filled between the sleeve 311 and the first conductor layer 31.
Similarly, a sleeve 151 made of a cylindrical good conductor (for example, copper) is attached to the outer periphery of the second superconducting conductor layer 150 of the first and second superconducting cables 10A and 10B. For example, solder is filled between the sleeve 151 and the second superconducting conductor layer 150.

One of the two second connection terminals 40B includes the second conductor layer 33 at one end of the connection cable 30 and the first superconducting conductor layer of the first superconducting cable 10A, the positions of which coincide with each other in the cable direction. 130 is sandwiched between a plurality of members, and staking is conducted between them.
The other second connection terminal 40B is connected to the second conductor layer 33 at the other end of the connection cable 30 and the first superconducting conductor layer 130 of the second superconducting cable 10B. Are sandwiched between a plurality of members, and are connected by caulking.
When sandwiching and caulking with a plurality of members, sleeves 331 made of a cylindrical good conductor (for example, copper) are attached to the outer periphery of the second conductor layer 33 at both ends of the connection cable 30. For example, solder is filled between the sleeve 331 and the second conductor layer 33.
Similarly, a sleeve 131 made of a cylindrical good conductor (for example, copper) is attached to the outer periphery of the first superconducting conductor layer 130 of the first and second superconducting cables 10A and 10B. For example, solder is filled between the sleeve 131 and the first superconducting conductor layer 130.

  FIG. 5 is a view of the first connection terminal 40A as viewed from the cable direction. As shown in the figure, the first connection terminal 40A includes sleeves 311 and 151 that connect the first conductor layer 31 of the connection cable 30 and the second superconducting conductor layer 150 of the first or second superconducting cables 10A and 10B. A pair of symmetrical connecting members 41A and 42A (corresponding to a plurality of members) that are sandwiched and caulked by a plurality of members via three, and three bolts 43A that connect the connecting members 41A and 42A and apply caulking pressure thereto And have. The pair of connection members 41A and 42A are both made of a good conductor such as metal (for example, copper), and the connection members 41A and 42A themselves serve as a current path.

  The connection members 41A and 42A have substantially semicircular recesses 411A and 421A into which the sleeve 311 of the first conductor layer 31 is fitted, and a sleeve 151 of the second superconducting conductor layer 150, respectively. The substantially semicircular recesses 412A and 422A to be fitted are formed. These recesses 411A, 421A, 412A, and 422A are all formed in a range that is slightly less than 180 °, so that the clamping pressure to the sleeves 311 and 151 can be obtained by fastening the bolt 43A. ing.

  The recesses 411A and 421A and the recesses 412A and 422A are desirably arranged as close as possible to the extent possible in order to reduce electrical resistance. Similarly, in order to reduce the electrical resistance, the cross-sectional area of the portion between the recesses 411A, 421A and the recesses 412A, 422A should be increased within a range where the size and weight of the connection members 41A, 42A are allowed. Is desirable.

The connection members 41A and 42A are formed with insertion holes for bolts 43A at three positions so as to sandwich the recesses 411A and 421A and the recesses 412A and 422A. The insertion hole of the connection member 41A is a through hole into which the screw portion of the bolt 43A can be loosely inserted, and the insertion hole of the connection member 42A is a screw hole into which the screw portion of the bolt 43A is screwed.
As with the insertion hole of the connection member 41A, the insertion hole of the connection member 42A is a through hole in which the screw portion of the bolt 43A can be loosely inserted, and a nut is screwed into the screw portion to fasten the connection members 41A and 42A. You may do it.
Even when the insertion hole of the connecting member 42A is a screw hole into which the screw portion of the bolt 43A is screwed, the nut of the bolt 43A may be screwed into the screw portion of the bolt 43A and fastened.

The second connection terminal 40B has the same structure as the first connection terminal 40A except that the inner diameters of the recesses 411A and 421A of the first connection terminal 40A are different from the inner diameters of the recesses 412A and 422A. Is omitted.
That is, one recess of the second connection terminal 40B has an inner diameter that allows the sleeve 331 of the second conductor layer 33 of the connection cable 30 to be fitted and fastened, and the other recess is of the superconducting cables 10A and 10B. The inner diameter is such that the sleeve 131 of the first superconducting conductor layer 130 can be fitted and fastened.

[Assembly of intermediate connection part]
The assembly of the intermediate connecting portion 20 will be described.
First, the first and second superconducting cables 10A and 10B are stepped off from each other with their connection ends facing each other. At this time, it is desirable that the electrical insulating layer 113 has a slightly longer length for stripping and secures insulation by keeping a distance between the first connecting terminal 40A and the second connecting terminal 40B.
Also, the both ends of the connection cable 30 are stripped of each layer.

  Further, the heat insulating container 21 is assembled before and after the step stripping operation. At this time, the side plates 213 and 214 at one end of the heat insulating container 21 are not closed with respect to the inner tube 211 and the outer tube 212 until the connection work of the cables 10A, 10B, and 30 is finished.

Then, connection work of one end of the first superconducting cable 10A and the connection cable 30 and connection work of the second superconducting cable 10B and the other end of the connection cable 30 are performed.
First, the first conductor layer 31 at one end of the connection cable 30 and the second superconducting conductor layer 150 of the first superconducting cable 10A are sandwiched between the first connection terminals 40A via the sleeves 311 and 151, Caulking, sandwiching the second conductor layer 33 at one end of the connection cable 30 and the first superconducting conductor layer 130 of the first superconducting cable 10A between the second connection terminals 40B via sleeves 331 and 131, By caulking, the connection terminals 40A and 40B are fastened with bolts to be in an electrically connected state.

  After the intermediate portion of the connection cable 30 is spirally wound, the first conductor layer 31 at the other end of the connection cable 30 and the second superconducting conductor layer 150 of the second superconducting cable 10B are sleeved. Clamping the first connection terminal 40A via 311 and 151, and caulking, the second conductor layer 33 at the other end of the connection cable 30 and the first superconducting conductor layer 130 of the second superconducting cable 10B. Clamping is performed between the second connection terminals 40B via the sleeves 331 and 131, and the connection terminals 40A and 40B are fastened with bolts to be electrically connected.

As a result, the first superconducting cable 10A and the second superconducting cable 10B are electrically connected via the connection cable 30 and the first and second connection terminals 40A and 40B.
Then, the side plates 213 and 214 at one end of the heat insulating container 21 are also flange-connected to the inner tube 211 and the outer tube 212 (using a metal U tight seal (registered trademark)) to close the heat insulating container 21.
Before connecting the flange of the heat insulating container 21, it is desirable to provide an insulating structure around the connection terminals 40 </ b> A and 40 </ b> B, the exposed conductor layers 31 and 33, and the superconducting conductor layers 130 and 150. For example, examples of the insulating structure include winding of an insulating tape (for example, a Teflon (registered trademark) tape, PPLP, or the like).

[Technical effects of the first embodiment]
In the intermediate connection portion 20 of the superconducting cable, the superconducting conductor layers 130 and 150 of the first and second superconducting cables 10A and 10B are connected to the connecting cable 30 having a smaller diameter than the superconducting cables 10A and 10B. Since the connection terminals 40A and 40B are connected,
When each superconducting cable 10A, 10B expands or contracts due to a temperature change, the connecting cable 30 which is more flexible and deformable than the superconducting cables 10A, 10B allows these, and to the respective superconducting cables 10A, 10B side. It is possible to protect the superconducting cables 10A and 10B by suppressing the generation of excessive tension and compressive force and reducing these effects.
In particular, by making the connection cable 30 spirally wound or bent in the heat insulating container 21, it is possible to sufficiently cope even when the amount of expansion and contraction of each of the superconducting cables 10A and 10B is large. is there.

Also, the superconducting conductor layers 130 and 150 at the connection end of each superconducting cable 10A or 10B and the conductor layers 31 and 33 of the connecting cable 30 are connected by first and second connection terminals 40A and 40B that are held from the outside. As a result, welding work is not required, the work load can be reduced, and construction work can be facilitated.
In particular, the first and second connection terminals 40A and 40B have a structure in which the superconducting conductor layers 130 and 150 of each superconducting cable 10A or 10B and the conductor layers 31 and 33 of the connecting cable 30 are clamped by bolts. Therefore, it can be connected only by the fastening operation of the bolt, and the installation work of the intermediate connection portion 20 can be performed quickly and easily.

[Second Embodiment]
An intermediate connection portion 20C as a connection structure for connecting the first superconducting cable 10A and the second superconducting cable 10B will be described with reference to FIG. In this intermediate connection portion 20C, the same portions or the same configurations as those of the intermediate connection portion 20 described above are denoted by the same reference numerals, and redundant description is omitted.
The intermediate connecting portion 20C is provided with the inner pipe 211 of the heat insulating container 21 by welding the inner branch pipe 215C and the outer pipe 212 by welding the outer branch pipe 216C, and is branched from the inner branch pipe 215C. A double tube structure is formed by the outer tube 216C, and the first superconducting is branched separately from the path of the first superconducting cable 10A and the second superconducting cable 10B by the branching cable 30C passing the branching inner tube 215C. The current can be taken out from the cable 10A.

  The branch cable 30C has a conductor layer similar to that of the connection cable 30, and includes a first conductor layer 31, an electrical insulation layer 32, a second conductor layer 33, an electrical insulation layer 34, and a protective layer 35. Are stripped in order.

  The pair of connection members 41C and 42C of the first connection terminal 40C that connects the second superconducting conductor layer 150 of the first superconducting cable 10A and the first conductor layer 31 of the connecting cable 30 are shown in FIG. 7, in addition to the recesses 411A and 421A and the recesses 412A and 422A, recesses 413C and 423C for clamping the first conductor layer 31 of the branch cable 30C via the sleeve 311 are provided. Yes.

  The pair of connecting members of the second connection terminal 40D that connects the first superconducting conductor layer 130 of the first superconducting cable 10A and the second conductor layer 33 of the connecting cable 30 are the above-described second connecting members. In addition to the recesses formed in the connection terminal 40B, a recess for caulking the second conductor layer 33 of the branch cable 30C via the sleeve 331 is provided.

  Thus, according to the intermediate connection portion 20C that connects the first and second superconducting cables 10A and 10B using the connection terminals 40A to 40D and the connection cable 30, the conductor layer of the cable is connected to the connection terminals 40C and 40D. A branch path can be easily formed by increasing the number of recesses as holding parts, and it is possible to easily extract current from the intermediate connection part to the branch path side.

[Other examples of connection terminals]
In addition, the connection terminal is not limited to a method in which it is clamped by a plurality of members shown in FIG. For example, as shown in FIG. 8, the insertion type includes through holes 411E and 412E into which the conductor layers 31 and 33 of the connection cable 30 and the superconducting conductor layers 130 and 150 of the superconducting cables 10A and 10B can be inserted through a sleeve. The connection terminal 40E may be used.
In the case of this connection terminal 40E, in order to ensure a sufficient contact pressure with the inserted sleeve and to achieve conduction, the through holes 411E and 412E are formed with innumerable ridges inside, It is desirable that an infinite number of elastic conductive springs are laid in a ring shape.
In the case of such an insertion-type connection terminal 40E, the connection can be made simply by inserting the connection cable 30 and the superconducting cables 10A and 10B, so that the need for bolting and the like becomes unnecessary, and the installation of the intermediate connection portion is eliminated. The work can be performed more quickly and easily.
Further, the connection terminal 40E can be applied to other embodiments described later.

[Others]
The application of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
The connection cable 30 and the branch cable 30C use normal conductive cables whose conductor layer is formed of a copper conductor of a good conductor. As the connection cable 30 and the branch cable 30C, the superconducting cables 10A and 10B A superconducting cable composed of a plurality of layers having the same configuration as that of the cable core 11 may be used. In that case, it is desirable that the superconducting cable as the connection cable 30 or the branch cable 30 </ b> C has a smaller diameter than the cable core 11 so as to be more flexible and deformable than the cable core 11. Further, the connection cable made of the superconducting cable can be applied to other embodiments described later.
Further, when the superconducting conductor layer of the first superconducting cable and the superconducting conductor layer of the second superconducting cable are respectively provided with the positive electrode layer and the negative electrode layer, the magnetic field generated from the positive electrode layer and the magnetic field generated from the negative electrode layer are Since the cancellation of the superconducting characteristics due to the magnetic field is suppressed, the first superconducting cable and the second superconducting cable can be efficiently energized, but the connection cable also cancels the magnetic field in the same way. Efficient energization is also expected in
Thereby, it becomes possible to further reduce the loss and heat generation in the intermediate connection portion.

Further, in the intermediate connecting portion 20 described above, the first superconducting cable 10A is provided by a single connecting cable 30 having the same number of conductor layers 31 and 33 as the superconducting conductor layers 130 and 150 of the superconducting cables 10A and 10B to be connected. However, the number of superconducting conductor layers possessed by the superconducting cable and the number of connecting cables used for connection can be changed as appropriate.
For example, when connecting a superconducting cable 10A having two superconducting conductor layers 130 and 150 and a superconducting cable 10B, two connecting cables having only one conductor layer are used, and the superconducting cable 10A and the superconducting cable are used. 10B may be connected. Even in such a case, it is desirable that each connection cable be bent in the heat insulating container 21.

[Third embodiment]
As a connection cable 30 for connecting the superconducting conductor layers 130, 150 of the first superconducting cable 10A and the superconducting conductor layers 130, 150 of the second superconducting cable 10B, the one end and the other end are spirally wound. However, the connection cable 30 is not limited to such a shape. For example, as long as it can sufficiently cope with the contraction amount assumed for the superconducting cables 10A and 10B, as shown in FIG. 9, the one end and the other end may be simply loosened and connected.
By making the connecting cable 30 into such a slack shape, it is not necessary to perform processing or bending work into a spiral shape, and it is possible to facilitate and speed up the formability and workability of the intermediate connection portion 20 of the superconducting cable. It becomes possible to plan.

[Fourth embodiment]
The case where the superconducting conductor layers 130 and 150 of the first superconducting cable 10A and the superconducting conductor layers 130 and 150 of the second superconducting cable 10B are connected by one connecting cable 30 is illustrated, but as shown in FIG. In addition, a plurality of connection cables 30 may be used.

In that case, in order to use the two connection cables 30, the first connection terminal 40F and the second connection terminal 40G are used.
As shown in FIG. 11, the first connection terminal 40 </ b> F is a pair that connects the second superconducting conductor layer 150 of the first superconducting cable 10 </ b> A and the first conductor layers 31 of the two connecting cables 30. Connecting members 41F and 42F, and as shown in FIG. 11, the connecting members 41F and 42F are provided with concave portions 411A and 411A, respectively, on both sides (upper and lower sides in FIG. 11) with the concave portions 412A and 422A interposed therebetween. 421A is formed one by one.
The connecting members 41F and 42F are used to caulk the second superconducting conductor layer 150 of the first superconducting cable 10A and the first conductor layer 31 of each connecting cable 30 via the sleeves 151 and 311. Connections are made.

The second connection terminal 40G includes a pair of connection members that connect the first superconducting conductor layer 130 of the first superconducting cable 10A and the second conductor layer 33 of the two connecting cables 30; In these connection members, the second conductor layer 33 of the connection cable 30 is caulked on both sides of the concave portion for caulking the first superconducting conductor layer 130 of the first superconducting cable 10A. Are formed one by one.
The second connection terminal 40G is the same as the first connection terminal 40F except that the inner diameter of each recess is a size corresponding to the outer diameter of the first superconducting conductor layer 130 and the second conductor layer 33. Detailed illustration is omitted because of the same structure.

The first and second connection terminals 40F and 40G are also used for the connection between the second superconducting cable 10B and the two connection cables 30.
In this way, by connecting the first superconducting cable 10A and the second superconducting cable 10B using a plurality of connecting cables 30, a thin connecting cable 30 is used or a normal conducting conductor is connected. Even when the cable 30 is used, a large current capacity can be secured.

Needless to say, three or more connection cables 30 may be used.
FIG. 12 shows a first connection terminal 40H when three connection cables 30 are used.
The first connection terminal 40H holds the second superconducting conductor layer 150 of the first superconducting cable 10A in the center, and the first connecting terminals 40H are arranged around the second connecting conductors 30 at a uniform angular interval (120 °). In this structure, one conductor layer 31 is held.
That is, the first connection terminal 40H is provided with an arc-shaped recess 412H formed in an angle range of 120 ° in the central portion in order to caulk the second superconducting conductor layer 150 of the first superconducting cable 10A. A semicircular arc-shaped concave portion 411H for caulking the first conductor layer 31 of the connection cable 30 is formed in the two extended portions extended at an angle range of 120 ° on both sides of the concave portion 412H. Three connection members 41H are provided.
Then, these three connecting members 41H are arranged radially so that each recess 412H is circular at the center, and the extending portions of the adjacent connecting members 41H are fastened with two bolts 43A, respectively. The second superconducting conductor layer 150 of the first superconducting cable 10A and the first conductor layers 31 of the three connecting cables 30 are caulked and held to enable electrical connection.

The second connection terminal that connects the first superconducting conductor layer 130 of the first superconducting cable 10A and the second conductor layer 33 of the three connecting cables 30 is the first connecting terminal 40H. Since the inner diameter of each recess is the same as that of the first connection terminal 40H except that the inner diameter of each recess is the size corresponding to the outer diameter of the first superconducting conductor layer 130 and the second conductor layer 33, the detailed description will be given. Omitted.
Further, the first and second connection terminals 40H are also used for connection of the second superconducting cable 10B and the three connection cables 30.
The configuration using a plurality of connection cables 30 described above can be applied to both the above-described embodiment and the embodiment described later.

[Fifth embodiment]
Although the former 140 of the first superconducting cable 10A and the former 140 of the second superconducting cable 10B in the intermediate connection portion 20 of the superconducting cable described above remain separated, these formers 140 are connected to each other. You may do it.
The former 140 of the first superconducting cable 10 </ b> A and the former 140 of the second superconducting cable 10 </ b> B are each extended by stripping, and the leading ends thereof are connected by the connecting portion 141.
For example, the connecting portion 141 is formed by inserting one end portion and the other end portion of a rod-shaped steel material inside each former 140 and connecting each former 140 from one end portion and the other end portion of a cylindrical conductive metal tube. It can be formed by inserting and caulking from the outside. The connecting portion 141 may be formed by connecting the formers 140 by welding. Further, when good electrical conductivity between the formers 140 is not required, the formers 140 may be connected by a hooking structure such as a hook.

In this way, when the former 140 of the first superconducting cable 10A and the former 140 of the second superconducting cable 10B are connected by the connecting portion 141 to form the intermediate connecting portion 20 as a connecting structure, each superconducting cable 10A. When the expansion and contraction of 10B occurs due to some factor, the formers 140 restrain the superconducting cables 10A and 10B to some extent, thereby connecting to the superconducting conductor layers 130 and 150 of the superconducting cables 10A and 10B. It is possible to reduce the load generated at the connection portion with the cable 30 and protect the superconducting conductor layers 130 and 150.
As shown in FIG. 14, the connections between the formers 140 are also effective when the connection cables 30 are not spiral but are loosely connected.
Moreover, the structure which connects the formers 140 of each superconducting cable 10A, 10B is applicable to both the embodiment mentioned above and the embodiment mentioned later.

[Sixth embodiment]
As a sixth embodiment, an intermediate connection portion 20I as a superconducting cable connection structure suitable for assembly and an assembly method thereof will be described with reference to FIGS.
This intermediate connection part 20I is characterized in that a cylindrical outer tube 212I uses a heat insulating container 21I having a bellows structure 217I (bellows structure) at the center in the longitudinal direction. In addition, since it is the same as that of the intermediate | middle connection part 20 mentioned above about structures other than these, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

Since the outer plate 212I of the heat insulating container 21I has a structure in which the side plates 214 closing both ends thereof are outside the side plate 213 of the inner tube 211, the outer tube 212I is longer than the inner tube 211. It is necessary to set as follows. On the other hand, if the outer tube 212I is longer than the inner tube 211, when the side plate 213 is attached to both ends of the inner tube 211, the attachment position is inside the outer tube 212I. It becomes difficult.
Therefore, a bellows structure 217I is provided at the center of the outer tube 212I to facilitate expansion and contraction. As a result, when performing the operation of attaching the side plate 213 to both ends of the inner tube 211, the bellows structure 217I is compressed so that both ends of the inner tube 211 are not hidden inside the outer tube 212I. To.
Further, when the side plate 214 is attached to both ends of the outer tube 212I, the bellows structure 217I is extended and attached to the outer tube 212I in a state where the side plate 214 is disposed outside the side plate 213. Is made possible.

The assembly of the intermediate connection portion 20I using the heat insulating container 21I will be described.
First, as shown in FIG. 15, the first and second superconducting cables 10A and 10B are stripped from each other with their connection ends facing each other, and the first and second superconducting cables 10A and 10B are separated. The side plates 213 and 214 of the heat insulation container 21I are connected to the respective heat insulation inner pipe 121 and heat insulation outer pipe 122 by welding or the like.
Then, inside the inner tube 211 and the outer tube 212I of the heat insulating container 21I, the superconducting cables 10A and 10B and the connection cable 30 are connected by the first and second connection terminals 40A and 40B. At this time, the connection cable 30 is stretched, and the connection between the superconducting cables 10A and 10B and the connection cable 30 is performed outside or near the outside of the ends of the inner tube 211 and the outer tube 212I. The outer tube 212I of the heat insulating container 21I keeps the bellows structure 217I in a contracted state.

Next, as shown in FIG. 16, the side plate 213 is flange-connected to both ends of the inner tube 211 of the heat insulating container 21I by fastening means such as bolts through a metal U tight seal (registered trademark).
Further, as shown in FIG. 17, the bellows structure 217I of the outer tube 212I of the heat insulating container 21I is extended, and the side plate 214 is attached to both ends of the outer tube 212I by a fastening means such as a bolt via a metal U tight seal (registered trademark). Connect the flange.
In addition, before connecting the flange of the heat insulation container 21, the insulating structure is provided around the connection terminals 40 </ b> A and 40 </ b> B, the exposed conductor layers 31 and 33, and the superconducting conductor layers 130 and 150 as in the case of the connection structure 20 described above. It is the same.
Then, evacuation is performed between the heat insulation inner tube 121 and the heat insulation outer tube 122 of the heat insulation tube 12 and between the inner tube 211 and the outer tube 212I of the heat insulation container 21I, and the assembly of the intermediate connection portion 20I is completed.

Thus, since the intermediate connection portion 20I includes the bellows structure 217I in the outer tube 212I of the heat insulating container 21I, the outer tube 212I can be contracted to perform flange connection of the side plate 213 of the inner tube 211. Since the outer tube 212I can be extended and the flange connection of the side plate 214 of the outer tube 212I can be performed, the workability can be improved and the burden of the laying operation of the intermediate connecting portion 20I can be reduced.
Note that the structure of the heat insulating container 21I is applicable to all the embodiments described above.

10A First superconducting cable 10B Second superconducting cable 20, 20C Intermediate connection (connection structure)
21, 21I Heat insulation container 212I Outer tube 217I Bellows structure 30 Connection cable 30C Branch cable 31 First conductor layer 33 Second conductor layer 32, 34 Electrical insulation layers 40A, 40C, 40F, 40H First connection terminals 40B, 40D, 40G Second connection terminal 40E Connection terminal 100 Superconducting wire 113, 115 Electrical insulation layer 130 Superconducting conductor layer 130, 150 Superconducting conductor layer 131, 151, 311, 331 Sleeve 150 Superconducting conductor layer 411A, 412A, 413C, 421A, 422A Concave part 411E, 412E Through-hole

Claims (9)

A connection structure for connecting the first and second superconducting cables,
A connection cable comprising a conductor layer;
A superconducting conductor layer of the first or second superconducting cable and at least two connection terminals for holding the conductor layer of the connecting cable;
The superconducting conductor layer of the first superconducting cable and the conductor layer at one end of the connection cable are connected by one of the connection terminals,
The superconducting cable connection structure, wherein the superconducting conductor layer of the second superconducting cable and the conductor layer at the other end of the connecting cable are connected by the other connecting terminal. The superconducting cable connection structure according to claim 1, wherein the superconducting cable includes a plurality of superconducting conductor layers concentrically. A plurality of the connection terminals are provided,
With any one of the connection terminals, a portion exposed by stepping of the superconducting conductor layer of the first superconducting cable and a portion exposed by stepping of the conductor layer at one end of the connection cable are connected,
A portion exposed by stepping of the superconducting conductor layer of the second superconducting cable and a portion exposed by stepping of the conductor layer at the other end of the connection cable by any other connecting terminal. The superconducting cable connection structure according to claim 2, wherein the superconducting cable is connected. The superconducting cable connection structure according to any one of claims 1 to 3, wherein the connecting cable has a smaller diameter than the first and second superconducting cables.   The superconducting cable connection structure according to any one of claims 1 to 4, wherein the connection cable is a superconducting cable, and the conductor layer is a superconducting conductor layer. A heat insulating container for storing the connection ends of the first and second superconducting cables and the connection cable;
The superconducting cable connection structure according to claim 1, wherein the connection cable is stored in a bent state or a spiral state in the heat insulating container.   The connection terminal sandwiches the superconducting conductor layer of the first or second superconducting cable and the conductor layer of the connecting cable by a plurality of members, and conducts by caulking. The superconducting cable connection structure according to any one of the above.   7. The connection terminal according to claim 1, wherein the connection terminal conducts the superconducting conductor layer of the first or second superconducting cable and the conductor layer of the connecting cable by insertion. 8. Connection structure of the described superconducting cable.   The superconducting cable connection structure according to any one of claims 1 to 8, wherein the former of the first superconducting cable and the former of the second superconducting cable are connected to each other.

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