JP2018129128A - Superconductive cable, and connected part of superconductive cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize a current to flow favorably by reducing a variation of connection resistances of a plurality of superconductive wire rods connected to an electrode.SOLUTION: The superconductive cable includes: a superconductor layer formed by winding a plurality of superconductive rods around a core material in a circular form; and a superconductive wire rod for circumferentially setting wound around an outer periphery of the super conductor layer, and electrically connected to each of a plurality of the super conductive wire rods of the super conductor layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a superconducting cable and a connecting portion of the superconducting cable.

  In a generally known configuration of a superconducting cable capable of transmitting a large-capacity current with low loss compared to a normal conducting cable, a superconducting tape is spirally wound around the outer periphery of a former (core material). In addition, in the superconducting cable, a structure is also known in which superconducting tapes are concentrically arranged in multiple layers to enable large current transmission. Between the layers of the superconducting tapes arranged in multiple layers (that is, between the superconducting tapes), a presser tape is provided for pressing the superconducting tape and for electrically insulating the superconducting tape.

  When the superconducting cable having such a layer structure is applied to a superconducting application device, for example, as shown in Patent Document 1 and Patent Document 2, a superconducting tape of a superconducting cable and an external power source, an external circuit, a normal temperature cable, or the like A terminal structure in which a metal terminal (electrode) connected to a device installed on the side is electrically connected is used.

  In the terminal structures of Patent Document 1 and Patent Document 2, the terminal of the superconducting cable in which the superconducting tape is arranged in layers is connected to an installed device installed on the normal temperature side, such as a normal conducting cable, and It is inserted into a cylindrical metal terminal having an inner diameter corresponding to the outer diameter of the layer made of superconducting tape. The superconducting tape and the metal terminal are electrically connected by pouring solder between the metal terminal and the layer of the superconducting tape inserted into the metal terminal.

JP 2010-287349 A JP 2013-178957 A

  By the way, in the conventional structure in which a superconducting cable is inserted inside a metal terminal and connected via solder, due to variations in connection length and connection accuracy in connection work, the amount of solder or the metal terminal and each Due to the difference in contact state with the superconducting tape, etc., the connection resistance between the metal terminal and each superconducting tape often varies. If the connection resistance varies, the current that does not flow through the superconducting wire with a high connection resistance will flow into the superconducting wire with a low connection resistance, which may exceed the allowable current amount and degrade the conductivity of the superconducting cable. . In Patent Document 2, for each superconducting wire of a superconducting cable connected to a normal conducting conductor corresponding to an electrode, by attaching a superconducting member for shunting along the respective longitudinal direction, a boundary portion between the superconducting wire and the normal conducting conductor The current concentration at is reduced.

  However, in Patent Document 2, in each superconducting wire, when there is variation in the connection resistance with the normal conductor to which each is connected, particularly when power is transmitted from the normal conductor side to the superconducting cable side, the current flowing through the connection resistance Since the amount is determined, it is difficult to eliminate the difference in the magnitude of the current flowing for each superconducting wire due to variations in connection resistance.

  The present invention has been made in view of such a point, and a superconducting cable capable of reducing the variation in connection resistance of a plurality of superconducting wires connected to electrodes and uniforming the current to flow appropriately, and the connection of the superconducting cable The purpose is to provide a department.

One aspect of the superconducting cable of the present invention is:
A superconducting conductor layer in which a plurality of superconducting wires are wound in a circle around the core; and
A circumferential superconducting wire wound around an outer periphery of the superconducting conductor layer in a circumferential direction and electrically connected to each of the plurality of superconducting wires of the superconducting conductor layer;
The structure which has is taken.

One aspect of the connecting portion of the superconducting cable of the present invention is:
A superconducting cable configured as described above;
A cylindrical electrode which is disposed so as to surround the superconducting conductor layer of the superconducting cable, and is electrically joined to the superconducting conductor layer and the superconducting wire for peripheral wiring via a solder portion;
The structure which has is taken.

  According to the present invention, variation in connection resistance of a plurality of superconducting wires connected to electrodes can be reduced and current can be made to flow uniformly.

The side view which shows the structure of the connection part of the superconducting cable of Embodiment 1 which concerns on this invention. Longitudinal sectional view showing the main configuration of the connection part of the superconducting cable The perspective view which shows the principal part structure of the superconducting cable 1 is a cross-sectional view taken along line AA in FIG. The longitudinal cross-sectional view which shows the principal part structure of the modification 1 of the connection part of the superconducting cable of Embodiment 2 which concerns on this invention The longitudinal cross-sectional view which shows the principal part structure of the modification 2 of the connection part of the superconducting cable of Embodiment 3 which concerns on this invention

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a side view showing the configuration of the connecting portion of the superconducting cable according to the first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing the main configuration of the connecting portion of the superconducting cable.

  The connection part 10 of the superconducting cable 100 shown in FIG. 1 has the superconducting cable 100 and a cylindrical extraction electrode (hereinafter referred to as a cylindrical electrode) 210. In the example of the present embodiment, the cylindrical electrode 210 is connected to the superconducting tape 113a included in the superconducting cable 100, and the lead cable 230 is electrically connected. The cylindrical electrode 210 connects a normal temperature portion, which is a normal conductor, and one end of the superconducting cable 100 via a lead cable 230. In actual use, superconducting cable 100 and cylindrical electrode 210 are immersed in a cryogenic liquid such as liquid nitrogen. Then, the current of the superconducting cable 100 is drawn out to the room temperature portion by the lead cable 230 via the cylindrical electrode 210. For example, the lead cable 230 is led out into the air via a polymer sleeve (not shown) or the like. Note that the other end of the superconducting cable 100 is connected to another room temperature portion or the like via a cylindrical electrode formed in the same manner as the cylindrical electrode 210.

  In the connection part 10, the superconducting cable 100 is inserted into the cylindrical electrode 210 and electrically connected via the solder part 170 inside the cylindrical electrode 210.

  FIG. 3 is a perspective view showing a main configuration of the superconducting cable according to the present embodiment.

  As shown in FIGS. 1 and 2, a superconducting cable 100 includes a cable body 110 having a core material (former) 111 and a plurality of superconducting tapes 113a around which a pressing tape 112 is wound, and a superconducting wire for peripheral installation. 120.

  The core material 111 has a cylindrical shape, and is made of, for example, a stranded wire of Cu (copper). A pressing tape 112 made of a nonwoven fabric is wound around the outer periphery of the core material 111.

  On the outer periphery of the presser tape 112, as shown in FIG. 3, the superconducting tape 113a constituting the first superconducting conductor layer 113 is spirally spaced with a predetermined gap G between the tapes in the circumferential direction. It is wound. The presser tape 112 is configured as a layered insulating portion by winding a single non-woven fabric spirally without a gap.

  In the example of the present embodiment, ten superconducting tapes per layer are wound spirally at a predetermined interval. That is, each of the superconducting conductor layers 113 made of the superconducting tape 113a is composed of ten superconducting tapes 113a. In the superconducting cable 100, the number of superconducting tapes constituting the layer of the superconducting tape 113a may be any number, and may be composed of 10 or more such as 12, or at least one. As a layer made of the superconducting tape 113a, for example, ten superconducting tapes having a thickness of 0.1 mm and a width of 5 mm are wound at a twist pitch of 250 mm. As the presser tape 112, for example, a non-woven fabric having a thickness of 0.2 mm and a width of 45 mm is wound in half wrap (that is, half of the tape width is wound in an overlapping manner).

As a material of the superconducting tape 113a, various conventionally proposed superconducting materials can be used. Here, the superconducting tape 113a includes a substrate and, REBa _y Cu ₃ O _z system formed along the substrate on the substrate (RE is Y, Nd, Sm, Eu, 1 kind selected from Gd and Ho A superconducting layer which is a high-temperature superconducting thin film of the above-mentioned elements, wherein y ≦ 2 and z = 6.2 to 7.).

  The superconducting tape (YBCO superconducting wire) 113a has a tape shape, and is formed by sequentially laminating an intermediate layer, a tape-shaped superconducting layer, and a stabilizing layer on a tape-shaped metal substrate. In the superconducting tape 113a, it is preferable that the laminated structure including the substrate, the intermediate layer, the superconducting layer, and the stabilizing layer is covered with a covering material made of a conductive material (copper).

  The substrate may be, for example, Ni—Cr (specifically, Ni—Cr—Fe—Mo based Hastelloy (registered trademark) B, C, X, etc.), W—Mo, Fe—Cr (eg, austenite). Stainless steel) or Fe—Ni (for example, non-magnetic composition type) and other low magnetic crystal grain non-oriented / heat resistant high strength metal substrates.

The intermediate layer has, for example, a plurality of layers such as a diffusion preventing layer for preventing element diffusion from the substrate from reaching the superconducting layer and an orientation layer for orienting the crystals of the superconducting layer in a certain direction. For example, the intermediate layer has an Al ₂ O ₃ layer as a first intermediate layer formed by sputtering on a substrate, and an RF sputtering method, an ion beam sputtering method, or the like is formed on the Al ₂ O ₃ layer. An amorphous LaMnO ₃ layer is formed as the second intermediate layer by sputtering. On this LaMnO ₃ layer, an MgO layer is formed as a third intermediate layer formed by the IBAD method or the like. On the MgO layer, there is a LaMnO ₃ layer as a fourth intermediate layer formed by a sputtering method, and a CeO ₂ layer as a fifth intermediate layer formed by a sputtering method or the like on the LaMnO ₃ layer. Have. The first intermediate layer is replaced with Al ₂ O ₃ by using ReZrO (Re: Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, or one or more selected from them. May be formed by an RF-sputtering method or a MOD method. This first intermediate layer has high heat resistance and is a layer for reducing interfacial reactivity, and also functions as a bed layer used for obtaining the orientation of the film disposed thereon.

The superconducting layer is typically an yttrium superconductor (YBCO layer) represented by YBa ₂ Cu ₃ O ₇ . In the superconducting layer of the superconducting tape 113a, oxide particles containing at least one of Zr, Sn, Ce, Ti, Hf, and Nb (particle size of 50 [μm] or less) are dispersed as magnetic flux pinning points. preferable. In this case, the TFA-MOD method using trifluoroacetate (TFA) is suitable as a method for forming the superconducting layer as the high-temperature superconducting thin film. For example, a Zr-containing oxide particle (BaZrO ₃ ) is added to a high-temperature superconducting thin film made of a RE-based superconductor by mixing a Zr-containing naphthenate having a high affinity with Ba into a Ba solution containing TFA. It can be distributed as flux pinning points. A known technique can be applied to the method of dispersing the magnetic flux pinning points in the high-temperature superconducting thin film (for example, JP 2012-059468 A). By dispersing the magnetic flux pinning points in the high-temperature superconducting thin film of the superconducting tape, even if the superconducting tape 113a is used in a curved state, it is hardly affected by the magnetic field and exhibits stable superconducting characteristics.

  The stabilization layer is a noble metal such as silver, gold, platinum, or an alloy thereof, and is formed on the superconducting layer with a low-resistance metal. The stabilization layer disperses the performance degradation caused by the direct contact of the superconducting layer directly below with noble metals such as gold and silver, or materials other than their alloys, and the heat generated by accident currents and alternating currents. To prevent destruction and performance degradation due to heat generation.

  As described above, the plurality of superconducting tapes 113a include a superconducting layer on the substrate. Then, in the superconducting cable 100, the plurality of superconducting tapes 113a are concentrically around the core member 111 with the superconducting layer side surface facing the outer peripheral side and the substrate side surface facing the inner peripheral side. Has been placed. That is, the superconducting tape 113a is disposed between the layered insulating portions formed of the pressing tape around the core material 111 so that the superconducting layer is wound on the outer peripheral side and the substrate is on the inner peripheral side. Superconducting cable 100 may have a plurality of layers of superconducting wires. When a multi-layer superconducting wire main body is provided, a presser tape is wound around the outer periphery of the superconducting tape 113 a in the same manner as the presser tape 112. A plurality of superconducting tapes 113a constituting the second superconducting conductor layer are wound around the outer periphery of the wound holding tape in a spiral shape at predetermined intervals in the circumferential direction, like the first superconducting tape 113a. Turned. In the case of this configuration, a pressing tape is wound around the outer periphery of the second superconducting tape in the form of a spiral without a gap, similarly to the pressing tape 112.

  Note that the superconducting cable 100 is actually provided with an electrical insulating layer, a superconducting shield layer, an external stabilization layer, a corrugated tube, and the like on the outer peripheral side of the holding tape wound around the outer periphery of the superconducting conductor layer 113. . However, since these members are removed at the terminal portion where the superconducting conductor layer 113 by the superconducting tape 113a is connected to the cylindrical electrode 210, these members are not shown in FIGS.

  The superconducting tape 113a of the superconducting cable 100 is directly electrically connected to the inner surface of the cylindrical electrode 210 into which the superconducting cable 100 is inserted via the solder part 170 between the inner surface.

In the superconducting cable 100, a circumferential superconducting wire 120 is wound around the outer periphery of the superconducting conductor layer 113 by the outermost superconducting tape 113a along the circumferential direction.
Specifically, the peripheral superconducting wire 120 is formed on the outer periphery of the superconducting conductor layer 113 composed of a plurality of superconducting tapes 113a arranged on the outermost periphery of the cable main body 110 of the superconducting cable 100, and the cable main body 110 or the core material. 111 is wound perpendicularly to the extending direction (longitudinal direction). That is, since the circumferential superconducting wire 120 is wound perpendicularly to the longitudinal direction, it is connected to all the superconducting tapes 113a existing in the circumferential direction. In the present embodiment, peripheral superconducting wire 120 wound around superconducting conductor layer 113 is joined to superconducting conductor layer 113 by solder.

  The circumferential superconducting wire 120 is electrically connected to each superconducting tape 113a of the superconducting conductor layer 113. Thereby, during operation of the superconducting cable 100, the current flowing for each superconducting tape 113a constituting the superconducting conductor layer 113 flows uniformly.

  The circumferential superconducting wire 120 may be configured in any manner as long as it is a conductive material, but in this embodiment, the superconducting tape 121 configured in the same manner as the superconducting tape 113a is the circumferential superconducting wire 120. Is forming. Thus, by using the superconducting tape 113a constituting the superconducting cable as the superconducting wire 120 for peripheral installation, it is not necessary to separately manufacture the superconducting wire 120 itself for peripheral installation, and the manufacturing cost can be reduced.

  The superconducting wire 120 for surroundings is directed to the superconducting conductor layer 113 side (core 111 side), that is, the superconducting layer of the superconducting wire 120 for surroundings is set to the inner peripheral side of the superconducting cable 100, and the substrate is It is wound around the superconducting conductor layer 113 toward the outer peripheral side.

  As a result, the superconducting layer of the superconducting tape 113a of the cable main body 110 and the superconducting layer of the surrounding superconducting wire 120 are arranged close to each other, and the conductive characteristics of the superconducting conductor layer 113 and the surrounding superconducting wire 120 are reduced. Improvements can be made.

  In the present embodiment, the circumferential superconducting wire 120 wound around the superconducting conductor layer 113 is disposed in the cylindrical electrode 210 together with the superconducting conductor layer 113, and is joined to the cylindrical electrode by the solder portion 170. The superconducting wire 120 for peripheral installation is wound around the superconducting conductor layer 113 and soldered at the position near the cylindrical electrode 210 to be connected in the superconducting conductor layer 113, as indicated by reference numeral 1200 in FIG. The current flowing through the superconducting wire of the superconducting conductor layer 113 may be made uniform.

  The tubular electrode 210 has a tubular shape as a whole and is formed of a conductive metal material such as Cu (copper). The cylindrical electrode 210 is electrically connected to the outer peripheral surface of the superconducting cable 100 disposed inside.

  As apparent from FIG. 2, the cylindrical electrode 210 has a cylindrical structure through which the superconducting cable 100 can penetrate. In addition, the cylindrical electrode 210 may be configured in a cylindrical shape by a plurality of divided sections having a semicircular cross-sectional shape divided along the extending direction of the superconducting cable 100. In the case of the divided body, the divided body is covered with a predetermined position of the superconducting cable 100 and is formed in a cylindrical shape by airtightly fixing each other in the circumferential direction.

  In cylindrical electrode 210 of the present embodiment, peripheral superconducting wire 120 is inserted and joined together with cable body 110 as superconducting cable 100.

  FIG. 4 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 2 and 4, the cylindrical electrode 210 has a solder hole 221 and an air hole 223 formed through the peripheral wall portion so that the inside and the outside communicate with each other.

  The long hole 221 for solder is formed in the cylindrical electrode 210 so as to penetrate the outer peripheral side and the inner peripheral side in the radial direction, and injects solder from the outer peripheral side of the cylindrical electrode 210 to the inner periphery.

  The solder long hole 221 is formed in the central portion of the upper surface portion of the cylindrical electrode 210 along the longitudinal direction. The solder elongated holes 221 are formed in the cylindrical electrode 210 along the longitudinal direction (axial direction) on both ends of the lead cable 230 connecting portion.

  Thereby, since the solder long hole 221 is arranged over substantially the entire length of the cylindrical electrode 210, the solder to be injected through the solder long hole 221 can be surely injected to every corner of both ends. .

  Further, the cylindrical electrode 210 is aligned with the solder elongated holes 221 on both ends of the solder elongated holes 221 and is injected at the time of injection of solder injected into the cylindrical electrodes 210 via the solder elongated holes 221. Air holes 223 for extracting air are respectively formed.

  In the cylindrical electrode 210, a long slot 221 for solder sandwiched between air holes 223 is formed at each of both ends. Since the hole for injecting the solder is a long hole in this way, bubbles entrained in the molten solder can be easily removed compared to the case of injecting the solder through the solder injection hole having a small cross-sectional area. As it becomes difficult to remain. Therefore, the contact area of the solder is not reduced by the gap, so that the connection resistance can be increased.

  In this way, the superconductivity is obtained by injecting the solder over the entire area inside the cylindrical electrode 210 and filling it without any gaps while removing the bubbles entrained when injecting the solder through the long hole 221 for solder. Variations in connection resistance between the tape 113a and the cylindrical electrode 210 can be suitably reduced.

  Also, the solder that is injected through the long hole 221 for soldering and joins the cylindrical electrode 210 and the superconducting conductor layer 113 (a plurality of superconducting tapes 113a) of the superconducting cable 100 is the superconducting wire 120 and the superconducting conductor layer. It is preferable that the solder has a melting point lower than that of the solder that joins 113. In the present embodiment, so-called high-temperature melting point solder is used for joining the superconducting conductor layer 113 and the surrounding superconducting wire 120, and joining of the cylindrical electrode 210 and the superconducting tape 113a is used to form the solder portion 170. Uses so-called low melting point solder.

  The solder elongated holes 221 and the air holes 223 can be used as confirmation holes for confirming the filling state of the solder injected into the cylindrical electrode 210 by visually recognizing or inserting a miniaturized camera or the like. The long solder holes 221 and the air holes 223 may be provided anywhere as long as the solder long holes 221 are sandwiched between the air holes 223 as long as no solder leakage occurs during filling.

  Inside the cylindrical electrode 210, the inner peripheral surface of the cylindrical electrode 210 and the superconducting conductor layer (layer formed by the superconducting tape 113 a) 113 located in the outermost layer in the cylindrical electrode 210 are energized through the solder part 170. It is possible to join (so-called direct attachment).

  The inner diameter of the cylindrical electrode 210 is substantially the same as the outer diameter of the circumferential superconducting wire 120 in the superconducting cable 100 disposed inside, or the circumferential superconducting wire 120 in the superconducting cable 100 disposed inside. It is formed in such a dimension that a gap is formed between the outer diameter and the outer diameter.

  When forming the solder part 170, a packing material for preventing solder leakage is provided in the gap between the inner peripheral surface of both ends of the cylindrical electrode 210 and the superconducting conductor layer 113 of the superconducting cable 100. After inserting, the space between the inner peripheral surface of the cylindrical electrode 210 and the outer peripheral surface of the superconducting conductor layer 113 is sealed, and then solder is injected through the solder elongated hole 221. The packing material (not shown) may be a sheet, an annular body, or a string-like body made of a soft material such as polytetrafluoroethylene (PTFE), silver, or indium.

  Superconducting cable 100 of the present embodiment is wound in the circumferential direction around superconductor layer 113 in which superconducting tape 113a, which is a plurality of superconducting wires, is wound around core material 111 in a circular shape, and on the outer periphery of superconducting conductor layer 113. And a superconducting wire 120 for peripheral installation electrically connected to each of the plurality of superconducting tapes 113a of the superconducting conductor layer 113. With this configuration, even if the values of current flowing through the plurality of superconducting tapes 113a in the superconducting conductor layer 113 are different due to variations in connection resistance values at one end of the superconducting cable, the superconducting wire 120 for peripheral installation is different. Can be made to flow more uniformly.

  In other words, in the present embodiment, all superconducting tapes (superconducting wires) 113a of the superconducting cable are integrally connected with the peripheral superconducting wires 120 (121), which are the same superconducting wires, in the vicinity of the cylindrical electrode (terminal) 210. Therefore, the current flowing between the cylindrical electrode 210, which is a copper terminal, and the superconducting tape (superconducting wire) 113a can be made uniform. In particular, even if the current value flowing from the cylindrical electrode 210 side to the superconducting tape 113a of the superconducting cable 100 varies due to the contact resistance of the cylindrical electrode 210, it is made uniform by the surrounding superconducting wire 120 and externally (other than the superconducting cable 100). Flow to the end side).

  According to the present embodiment, it is possible to reduce the variation in the connection resistance of the plurality of superconducting wires connected to the electrodes, to make the current uniform and to flow appropriately.

(Embodiment 2)
FIG. 5 is a longitudinal cross-sectional view showing the main configuration of Modification 1 of the connecting portion of the superconducting cable according to Embodiment 2 of the present invention.

  In the connecting portion 10A of the superconducting cable 100A shown in FIG. 5, the configuration of the superconducting cable 100A is different from that of the connecting portion 10 of the first embodiment, and the other configurations are the same.

  A connecting portion 10A of the superconducting cable 100A shown in FIG. 5 includes a superconducting cable 100A and a cylindrical extraction electrode (hereinafter referred to as a cylindrical electrode) 210.

  In the example of the present embodiment, the cylindrical electrode 210 is connected to each of the superconducting conductor layers (113-1, 113-2) each constituted by a plurality of superconducting tapes 113a in the superconducting cable 100. In addition, a lead cable 230 is electrically connected to each cylindrical electrode 210, and the cylindrical electrode 210 is connected to the normal temperature part which is a normal conductor via the lead cable 230 and one terminal of the superconducting cable 100. And connect. In actual use, the superconducting cable 100A and the cylindrical electrode 210 are immersed in a cryogenic liquid such as liquid nitrogen. Then, the current of the superconducting cable 100A is drawn out to the normal temperature part by the lead cable 230 via the cylindrical electrode 210. For example, the lead cable 230 is led into the air through a polymer sleeve (not shown) or the like as described above. The other end of the superconducting cable 100A is connected to another room temperature portion or the like via a cylindrical electrode formed in the same manner as the cylindrical electrode 210.

  In the connection portion 10A, the superconducting cable 100A is inserted into the cylindrical electrode 210 and is electrically connected to the inside of the cylindrical electrode 210 via the solder portion 170A.

  The superconducting cable 100A of the present embodiment includes a cable main body 110A having a plurality of superconducting conductor layers 113-1 and 113-2 on the outer periphery of the core 111 in the cable main body 110 of the first embodiment. Superconducting wires 120-1 and 120-2.

  In the cable body 110A, a superconducting tape similar to the superconducting tape 113a constituting the first superconducting conductor layer 113-1 is spiraled on the outer periphery of the superconducting conductor layer 113 in the cable body 110 via a pressing tape made of a nonwoven fabric. It is wound in a shape. These superconducting tapes are arranged with a certain predetermined gap (a predetermined gap G similar to the first superconducting conductor layer) between the tapes in the circumferential direction, and constitute the second superconducting conductor layer 113-2. . Note that the presser tape 112 between the first superconducting conductor layer 113-1 and the second 113-2 is layered by winding one non-woven fabric in a spiral shape without a gap. Configured as part. In addition, a pressing tape is wound around the outer periphery of the second superconducting conductor layer 113-2 by the second superconducting tape in the same manner as the pressing tape 112, and a single non-woven fabric is spirally wound with no gap. Yes. The first superconducting conductor layer 113-1 is the same as the superconducting conductor layer 113 of the first embodiment, and the second superconducting conductor layer 113-2 is formed in the same manner as the first superconducting conductor layer 113. The

  In the superconducting cable 100A, the end of the cable connected to the cylindrical electrode 210 is stepped, and the first superconducting conductor layer 113-1 and the second superconducting conductor layer 113-2 are exposed as outer peripheral surfaces in order from the terminal side. doing.

  The superconducting cable 100A is wound in the circumferential direction on the outer circumferences of the exposed superconducting conductor layers 113-1 and 113-2 and the superconducting conductor layers 113-1 and 113-2, and the plurality of superconducting conductor layers. Peripheral superconducting wires 120-1 and 120-2 electrically connected to the respective superconducting wires.

  In the present embodiment, the superconducting wires 120-1 and 120-2 for peripheral installation are respectively extended along the circumferential direction of the superconducting conductor layers 113-1 and 113-2 (in the direction of the superconducting cable). It is wound perpendicularly to the (longitudinal direction). The circumferential superconducting wires 120-1 and 120-2 are electrically connected to the respective superconducting tapes constituting the superconducting conductor layers 113-1 and 113-2 by soldering.

  Also, these superconducting wires 120-1 and 120-2 for peripheral installation are formed by the superconducting tape 113a as in the first embodiment, and are on the respective superconducting conductor layers 113-1 and 113-2 (corresponding to the inner diameter side). Are wound with the superconducting layer side facing.

  In the cylindrical electrode 210, superconducting conductor layers 113-1 and 113-2 formed in a plurality of layers in the superconducting cable 100A, and a superconducting wire 120- around the outer periphery of the superconducting conductor layers 113-1 and 113-2. 1 and 120-2 are arranged. The cylindrical electrode 210, the superconducting conductor layers 113-1 and 113-2, and the surrounding superconducting wires 120-1 and 120-2 are electrically connected via a solder portion 170A made of solder. Note that the solder portion 170A is formed by injecting solder from the elongated solder hole 221 as in the first embodiment.

  According to the present embodiment, superconducting cable 100A has a plurality of peripheral superconducting wires 120-1 and 120-2. Superconducting conductor layers 113-1 and 113-2 are laminated on the outer periphery of core material 111. The outer periphery of the outer superconducting conductor layer 113-2 of the superconducting conductor layers 113-1 and 113-2 to be stacked, and the lower superconducting conductor exposed by stepping off the outer superconducting conductor layer 113-2. Circumferential superconducting wires 120-1 and 120-2 are respectively wound around the outer periphery of the conductor layer 113-1. The plurality of circumferential superconducting wires 120-1 and 120-2 are disposed in the cylindrical electrode 210, and the cylindrical electrode 210 is connected to the plurality of superconducting conductor layers 113-1 and 113-2 via the solder portion 170A. It is airtightly bonded together with the superconducting tape (superconducting wire) 113a.

  As a result, the same effect as that of superconducting cable 100 of the first embodiment described above can be obtained for each of superconducting conductor layers 113-1 and 113-3, and each of superconducting conductor layers 113-1 and 113-2 is provided as one. It can connect suitably to the cylindrical electrode 210 in the state which reduced contact resistance, respectively.

(Embodiment 3)
FIG. 6 is a longitudinal sectional view showing a main part configuration of Modification 2 of the connection part of the superconducting cable according to Embodiment 3 of the present invention.

  In connection portion 10B of superconducting cable 100B shown in FIG. 6, only the configuration of superconducting cable 100B is different from that of connection portion 10 in the first embodiment, and the other configurations are the same.

  A connecting portion 10B of the superconducting cable 100B shown in FIG. 6 has a superconducting cable 100A and a cylindrical lead-out electrode (hereinafter referred to as a cylindrical electrode) 210.

  The superconducting cable 100B inserted into the cylindrical electrode 210 has a cable body 110B configured similarly to the cable body 101A. The cable body 110B has a plurality of superconducting conductor layers 113-3 and 113-4 that are stacked on the outer periphery of the core material 111 and are exposed as outer peripheral surfaces of the superconducting cable 100B. The cable main body part 110B is different from the cable main body part 110A in the step peeling position of the superconducting conductor layers 113-3 and 113-4. That is, in the cable main body 110B, the outer periphery of the inner superconducting conductor layer 113-3 is exposed by stepping off the outer superconducting conductor layer 113-4. Here, the inner periphery of one end of the cylindrical electrode 210 is exposed. To the other end through the inside of the cylindrical electrode 210. Superconducting conductor layer 113-4 is exposed and disposed outside one end of cylindrical electrode 210. Then, superconducting tapes 121, which are circumferential superconducting wires 120-3 and 120-4, are respectively wound around outer surfaces sandwiching the stepped portions of the superconducting conductor layers 113-3 and 113-4.

  Then, the superconducting conductor layers 113-3 and 113-4 of the peripheral superconducting wires 120-3 and 120-4 and the cable main body 110B are connected at the stepped portion by the solder portion 170B filled in the cylindrical electrode 210. doing. According to this configuration, it is possible to obtain the same effects as those of the second embodiment. That is, the superconducting tape 113a forming a plurality of superconducting conductor layers and the cylindrical electrode 210 can be easily and suitably connected with reduced contact resistance via solder, and a reliable and suitable current carrying capacity can be ensured.

  In addition, the superconducting tape 121 used with the superconducting wire 120 for circumference | surroundings has a large effect of equalization (equalization of an electric current), so that there are many numbers. The superconducting wires 120, 120-1, and 120-2 for peripheral installation may be configured by using two or more superconducting tapes 121.

<Example 1>
First, as a superconducting wire (superconducting tape), an intermediate layer formed by sequentially forming an Al ₂ O ₃ layer, a LaMnO ₃ layer, a MgO layer, a LaMnO ₃ layer, and a CeO ₂ layer on a Hastelloy (registered trademark) substrate. A REBa _y Cu ₃ O _z- based superconductor in which a superconducting layer composed of an yttrium-based superconductor (YBCO layer) represented by YBa ₂ Cu ₃ O ₇ and a silver stabilizing layer are sequentially formed on the intermediate layer The wire was formed with a thickness of 0.12 mm and a width of 5 mm. 30 of these were wound around a copper core material 111 having an outer diameter of 19 mm to form a superconducting wire layer (for example, a superconducting conductor layer 113), and a cable main body 110 including this was formed. One peripheral superconducting wire was wound around the outer surface of the cable body 110 perpendicularly to the longitudinal direction and soldered, and inserted into the cylindrical electrode 210 shown in FIG. 2 made of copper and having a thickness of 3 mm. The position of the superconducting wire for peripheral installation at that time is within the end portion 210a (the end portion on the base end side of the superconducting cable 100) 210a that opens on the side where the inserted cable body 110 is led out. Opposite to the peripheral surface, the edge on the base end side of the superconducting wire for peripheral installation was positioned so as to overlap the opening edge. In this position, the superconducting wire for superconducting wire and superconducting cable main body 110 and the cylindrical electrode 210 are soldered, and the current is equalized (5 mm) using a single superconducting wire for peripheral installation. Assemble the connection. In the connection part thus assembled, the connection resistance between the cylindrical electrode and each superconducting wire was measured by the DC four-terminal method (at 77K). Specifically, a voltage terminal is attached to a superconducting wire around the cylindrical electrode and in the vicinity of the cylindrical electrode, a current is passed between the cylindrical electrode and the superconducting wire in liquid nitrogen, and a generated voltage between the voltage terminals is measured. Was used to calculate the resistance value. The maximum value, the minimum value, the average value, and the standard deviation of the connection resistance for every 30 superconducting wires were calculated. These are shown in Table 1.

<Example 2>
Using the same superconducting wire (superconducting tape) as in Example 1, the same cable body 110 as in Example 1 is formed, and the peripheral superconducting wire of Example 1 is formed on the outer surface of this cable body 110. The book was wound in a direction perpendicular to the longitudinal direction and soldered. As in Example 1, this was inserted into the cylindrical electrode 210 shown in FIG. 2 and positioned at the position shown in FIG. That is, the two superconducting wires for peripheral installation are positioned on the end portion 210a side of the cylindrical electrode 210 as in the first embodiment, and the other one is adjacent to the cylindrical electrode 210. Located within. At this position, two circumferential superconducting wires and superconducting cable main body 110 and the cylindrical electrode 210 are soldered to equalize (10 mm) using one circumferential superconducting wire. The connection part of Example 2 was assembled. In the connection part of Example 2 assembled in this way, as in Example 1, the connection resistance between the cylindrical electrode and each superconducting wire was measured by the DC four-terminal method as in Example 1 (at 77K). The maximum value, the minimum value, the average value, and the standard deviation of the connection resistance for every 30 superconducting wires were calculated. These are shown in Table 1.

<Comparative Example 1>
In the structure of the connection part of the superconducting cable of Example 1, the cable body 110 without the surrounding superconducting wire is inserted into the cylindrical electrode 210 without using the surrounding superconducting wire, and the cylindrical electrode is attached. The connection of Comparative Example 1 was assembled by heating and soldering to connect the superconducting cable and the cylindrical electrode. In the connection portion of Comparative Example 1, the connection resistance between the cylindrical electrode and each superconducting tape was measured in the same manner as in Example 1. The maximum value, the minimum value, the average value, and the standard deviation of the connection resistance for every 30 superconducting wires were calculated. These are shown in Table 1.

  When Examples 1 and 2 and Comparative Example 1 are compared, Examples 1 and 2 have lower average values and standard deviations of connection resistance than Comparative Example 1, and there is a difference between the superconducting cable and the cylindrical electrode. It was found that providing a superconducting wire for peripheral installation at the connecting portion has the effect of leveling.

  The connection part of the superconducting cable according to the present invention includes a superconducting cable having a superconducting layer on a substrate, and a superconducting cable wound around the core so that the superconducting layer is on the inner peripheral side and the substrate is on the outer peripheral side. It has the effect of being able to be easily and suitably connected to an electrode with reduced contact resistance, and is useful as a connection part for a multilayer superconducting cable.

10, 10A, 10B Connection part 100, 100A, 100B Superconducting cable 110, 110A, 110B Cable body part 111 Core material 112 Pressing tape 113a, 121 Superconducting tape 113, 113-1, 113-2, 113-3, 113-4 Superconducting conductor layer 120, 120-1, 120-2, 120-3, 120-4, 1200 Circumferential superconducting wire 170, 170A, 170B Solder part 210 Cylindrical electrode 221 Solder slot 223 Air hole

Claims (6)

A superconducting conductor layer in which a plurality of superconducting wires are wound in a circle around the core; and
A circumferential superconducting wire wound around an outer periphery of the superconducting conductor layer in a circumferential direction and electrically connected to each of the plurality of superconducting wires of the superconducting conductor layer;
Having
Superconducting cable. The superconducting wires and the peripheral superconducting wires are each formed on a tape-like substrate, with a superconducting layer formed through an intermediate layer,
The superconducting conductor layer is formed by winding the plurality of superconducting wires around the outer periphery of the core member with the substrate facing the inner peripheral side and the superconducting layer facing the outer peripheral side with respect to the core member. And
The peripheral superconducting wire is wound around the superconducting conductor layer with the superconducting layer on the inner peripheral side and the substrate facing the outer peripheral side,
The superconducting cable according to claim 1. The superconducting cable according to claim 1 or 2,
A cylindrical electrode disposed so as to surround the superconducting conductor layer of the superconducting cable, and the circumferential superconducting wire is electrically joined via a solder portion;
Having
Superconducting cable connection. Having a plurality of the superconducting wires for circumferential installation,
The superconducting conductor layer is stacked on the outer periphery of the core member, and the outer periphery of the outer superconducting conductor layer of the plurality of stacked superconducting conductor layers and the outer superconducting conductor layer are exposed by stepping off. The peripheral superconducting wire is wound around each of the outer peripheries of the superconducting conductor layers on the side,
A plurality of the circumferential superconducting wires are disposed in the cylindrical electrode, and are electrically joined to the cylindrical electrode together with the plurality of superconducting conductor layers via the solder portion.
The connection part of the superconducting cable according to claim 3. The cylindrical electrode is provided penetrating in an outer peripheral side and an inner peripheral radial direction, and has a long hole for solder for injecting solder from the outer peripheral side of the cylindrical electrode to the inner periphery.
The connection part of the superconducting cable according to claim 3 or 4. In the cylindrical electrode, air holes are respectively formed on both end sides of the solder elongated hole in line with the solder elongated hole.
The connection part of the superconducting cable according to claim 5.

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