JP6947509B2 - Terminal structure of normal conductive connection member and superconducting cable - Google Patents

Description

The present invention relates to a normal conductive connection member used for a terminal connection portion of a superconducting cable and the terminal structure of a superconducting cable.

Conventionally, a superconducting cable using a superconducting wire material that becomes superconducting at an extremely low temperature as a conductor is known. Superconducting cables are expected as power cables capable of transmitting large currents with low loss, and are being developed for practical use.

A superconducting cable is known to have a structure in which a single-core or multi-core cable core is housed in a heat insulating tube. The single-core cable core includes, for example, a former, a superconducting conductor layer, an electrically insulating layer, a cable shield layer, a protective layer, and the like in order from the center. Further, as a cable core, a coaxial type cable core having a plurality of superconducting conductor layers concentrically arranged on the outer periphery of a former in which superconducting conductor layers and electrically insulating layers are alternately arranged concentrically is known.

Insulated pipes are an inner pipe that houses a cable core and is filled with a refrigerant (for example, liquid nitrogen) (hereinafter referred to as "insulated inner pipe") and an outer pipe that covers the outer circumference of the insulated inner pipe (hereinafter referred to as "insulated outer pipe"). Has. A vacuum is created between the adiabatic inner pipe and the adiabatic outer pipe for heat insulation.

In the terminal structure of a superconducting cable applied to the terminal connection portion of a superconducting cable, the terminal portion of the superconducting cable is housed in a low temperature container which is a low temperature portion, and the conductor of the superconducting cable (for example, the superconducting conductor layer) is the lead portion. It is pulled out to the normal temperature part through the conductor pull-out part. The low-temperature container has a double structure consisting of a refrigerant tank that houses the terminal portion of the superconducting cable and is filled with a refrigerant such as liquid nitrogen during operation, and a vacuum tank that houses the refrigerant tank and is in a vacuum state during operation.

In such a terminal structure of a superconducting cable, as a structure for connecting the superconducting conductor layer of the superconducting cable and the normal conducting connecting member connected to the conductor lead-out portion in a refrigerant tank filled with liquid nitrogen, for example, , The terminal structure of the superconducting cable shown in Patent Document 1 is known.

In the terminal structure of Patent Document 1, the core material of the superconducting cable provided with the superconducting tape is inserted into the annular normal conducting connecting member (corresponding to the electrode) connected to the conductor drawing portion, and the side surface of the normal conducting connecting member. It is connected by attaching a superconducting tape to the. The conductor drawing portion and the normal conducting connecting member are included in the lead portion.

Further, in Patent Document 2, a normal conduction connecting member in which an annular inner flange to which a superconducting tape of a superconducting cable is connected is rotatably and electrically attached around the superconducting cable to the inside of the annular outer flange. It is disclosed.

By the way, in the configuration in which the lead portion is installed at the end of the superconducting cable, it is conceivable to lengthen the conduction heat path in order to reduce the amount of heat intrusion from the outside.

In the normal conduction connection member of Patent Document 2, a plurality of concentric slots penetrating the front and back surfaces of the flange are provided to secure a current-carrying distance between the terminal and the inner flange.

As a result, the normal conduction connecting member of Patent Document 2 has a longer energized portion and a longer conduction heat path as compared with Patent Document 1, and transmits the conduction heat path to the superconducting conductor layer of the superconducting cable. The ingress of heat to be transferred is reduced.

Japanese Unexamined Patent Publication No. 2016-195485 U.S. Patent Application Publication No. 2012/289405

When the normal conductive connection member of Patent Document 2 is connected to a large-capacity superconducting cable, it is necessary to increase the cross-sectional area of the energized portion in order to secure an allowable current. As a means for increasing the cross-sectional area, the thickness of the normal conduction connecting member is increased, but if the thickness of the normal conducting connecting member is increased, it is technically difficult to open a slot penetrating the outer flange.

Further, when the normal conducting connection member of Patent Document 2 and the superconducting cable are connected and energized, in the case of direct current energization, the direct current flows through the entire energization region (conductor) of the normal conduction connection member, but alternating current energization. At times, it is known that due to the action of the self-magnetic field, current flows only on the surface of the energized portion. This is known as the so-called skin effect. In alternating current energization, the magnetic field is concentrated in the center of the energized portion due to the action of the self-magnetic field, making it difficult for current to flow, and the surface of the energized portion between slots. Current increases.

Therefore, in the normal conducting connection member of Patent Document 2, the non-energized portion that does not contribute to energization increases due to the skin effect during AC energization, and Joule heat generation increases without reducing the conduction heat, that is, to the superconducting conductor layer. There is a risk that the amount of heat intrusion cannot be reduced.

Since the connection target of the lead having the normal conduction connecting member is a superconducting cable, it is desired to have a configuration in which the amount of heat intrusion from the outside is not transmitted while increasing the amount of current.

An object of the present invention is a superconducting connection member and a superconducting member capable of reducing the amount of heat invading the superconducting cable from the outside while ensuring a suitable energizing capacity when connecting the superconducting cable and the superconducting portion. It is to provide the terminal structure of the cable.

The normal conduction connecting member according to the present invention is
A member that is connected to a superconducting cable and electrically connects the superconducting cable to equipment at room temperature, and is a normal conducting connection member used for alternating current energization.
A cable connection that is electrically connected to the superconducting cable,
Has a terminal portion connected to the device, a conductive portion for continuously with the with the terminal portions cable connection, and a plurality of conductive flange comprising,
The thickness of each of the plurality of conductive flanges is less than twice the skin depth determined by the energization conditions .

The terminal structure of the superconducting cable according to the present invention may have a configuration including a normal conducting connecting member having the above configuration and a superconducting cable connected to the normal conducting connecting member.

According to the present invention, when connecting the superconducting cable and the normal conducting portion, it is possible to reduce the amount of heat invading the superconducting cable from the outside while ensuring a suitable energizing capacity.

It is a figure which shows the terminal structure which concerns on one Embodiment of this invention. It is sectional drawing which shows the schematic structure of the superconducting cable in the terminal structure which concerns on one Embodiment of this invention. It is a front view which shows the connection part of the normal conduction connection member and a superconducting cable in the terminal structure which concerns on one Embodiment of this invention. It is a side surface which shows the connection part of the normal conduction connection member and the superconducting cable in the terminal structure which concerns on one Embodiment of this invention. It is sectional drawing which shows the modification of the conductive flange. The current-carrying region in the normal-conducting connecting member of the present embodiment is shown, FIG. 6A is a plan view of the normal-conducting connecting member, and FIG. 6B is a cross-sectional view taken along the line BB of FIG. 6A. It is a side view which shows the modification of the normal conduction connection member in the terminal structure of the superconducting cable of embodiment which concerns on this invention. It is a side sectional view which shows the modification. A current-carrying region in a normal-conducting connecting member as a modification of the present embodiment is shown, FIG. 9A is a plan view of the normal-conducting connecting member, and FIG. 9B is a sectional view taken along line CC of FIG. 9A.

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

FIG. 1 is a diagram showing a terminal structure 1 according to an embodiment of the present invention. For convenience of explanation, the side on which the superconducting cable 10 is introduced will be referred to as the rear end side (right side in FIG. 1), and the opposite side will be referred to as the front end side (left side in FIG. 1 and also referred to as the insertion direction side).

As shown in FIG. 1, the terminal structure 1 includes a terminal portion of a superconducting cable 10, a normal conductive connection member 30, a low temperature container 20 having a refrigerant tank 21 and a vacuum tank 22, and a support leg portion (support portion) 28. Has.

In the terminal structure 1, normal conductive connecting members 30 through which the superconducting cable 10 is inserted are arranged at predetermined intervals in the central portion. The refrigerant tank 21 is formed by erection of a cylindrical inner accommodating piece 211 so as to surround the superconducting cable 10 between the normal conductive connecting members 30. Further, the vacuum tank 22 is formed by erection of a cylindrical outer accommodating piece 221 so as to surround the refrigerant tank 21.

That is, the low temperature container 20 includes an inner refrigerant tank 21 composed of the normal conducting connection member 30 and the inner containing piece 211, and an outer vacuum tank 22 composed of the normal conducting connecting member 30 and the outer containing piece 221. It has a double structure.

The terminal portion of the superconducting cable 10 is housed in the low temperature container 20 (specifically, the refrigerant tank 21) configured in this way so as to extend in the horizontal direction in a predetermined state.

The conductor current of the superconducting cable 10 is drawn from the low temperature container 20 to the actual system side of the electric power device or the like via the normal conducting connecting member 30 (specifically, the terminal portion 301 of the normal conducting connecting member 30 shown in FIG. 3).

As with the normal conductive connection member 30, a shielded current-carrying portion may be provided, and the cable shield layer 114 (see FIG. 2) of the superconducting cable 10 may be grounded to the shielded current-carrying portion.

The superconducting cable 10 of the present embodiment has a multi-layered superconducting conductor layer made of a superconducting wire, and is predetermined in the horizontal direction for each superconducting conductor layer from the superconducting cable 10 arranged substantially horizontally in the terminal structure 1. At intervals, the conductor current is drawn through the normal conducting connection member 30.

FIG. 2 is a cross-sectional view showing a schematic configuration of a superconducting cable in the terminal structure according to the embodiment of the present invention.

As shown in FIGS. 1 and 2, the superconducting cable 10 has a superconducting conductor layer 112 in the heat insulating tube 12 via an electrically insulating layer (conductor insulating layer) 113 (113-1, 113-2, 113-3). This is a superconducting cable in which a cable core 11 having a plurality of (112-1, 112-2, 112-3) concentrically provided is housed. The superconducting cable 10 may be a multi-phase superconducting cable in which currents having different phases are passed through each superconducting conductor layer. Here, the superconducting conductor layer is a three-phase coaxial superconducting cable having three layers coaxially as a conductor through which U-phase, V-phase, and W-phase currents flow from the center.

Cable core 11, for example, from the center in order, the central cooling tube 111 is _{N 2} cooling pipe, a first superconducting conductor layer 112-1, the first electrically insulating layer (conductor-insulation layer) 113-1, a second superconducting conductor layer 112 -2, 2nd electrical insulation layer (conductor insulation layer) 113-2, 3rd superconducting conductor layer 112-3, 3rd electrical insulation layer (conductor insulation layer) 113-3, cable shield layer 114, protective layer 115, etc. Has.

Each superconducting conductor layer 112 and cable shield layer 114 are composed of, for example, a large number of superconducting tapes (tape-shaped superconducting wires) spirally wound around the outer surface of the lower layer. The superconducting tapes constituting the superconducting conductor layer are arranged so as not to overlap each other.

The superconducting tape is _here, REBa y _Cu 3 _{O z} system (RE is Y, Nd, Sm, Eu, represents one or more elements selected from Gd, and Ho, y ≦ 2 and z = 6.2 It is an oxide superconducting material provided with a high-temperature superconducting thin film (~ 7). In this superconducting tape, an oxide superconducting layer (hereinafter referred to as "superconducting layer"), which is a tape-shaped superconducting thin film, and a stabilizing layer are laminated in this order on an intermediate layer formed on a tape-shaped metal substrate. It is made by The metal substrate of the superconducting tape is nickel (Ni), nickel alloy, or stainless steel. The intermediate layer is formed on, for example, a metal substrate with an aluminum oxide (Al ₂ O ₃ ) layer, a gallium-doped zinc oxide layer (Gd ₂ Zr ₂ O ₇ : GZO), yttria-stabilized zirconia (YSZ), or the like. 1 layer, _{2nd layer which is a layer of Y2O 3} or lanthanum oxide (LaMnO ₃ ) or the like, 3rd layer which is composed of magnesium oxide (MgO) or the like, 4th layer which is a layer of _{LaMnO 3 or the like, cerium oxide (} It is configured by laminating the fifth layer, which is the CeO _{2) layer, in order.}

The superconducting layer is formed on the intermediate layer by the MOD method (Metal Organic Deposition Processes) without using a vacuum process using an organic metal salt or an organic metal compound as a raw material. In the MOD method, a thin film as a superconducting layer is formed on a composite substrate by heating and thermally decomposing a metal organic acid salt on a composite substrate having an intermediate layer on the metal substrate.

On the composite substrate, the superconducting tape configured in this way is composite with the superconducting layer (superconducting thin film) on the outer periphery of the lower central cooling tube 111 and the electrically insulating layer 113 (113-1, 113-2). Each superconducting conductor layer 112 is configured by spirally winding the substrate so that the substrate is on the inner peripheral side.

Each of the electrically insulating layers 113 is formed by winding, for example, semi-synthetic insulating paper around the outer periphery of the lower superconducting conductor layer 112.

The protective layer 115 is formed by winding kraft paper or the like around the outer circumference of the cable shield layer 114, for example.

In the terminal portion of the superconducting cable 10, as shown in FIG. 1, the cable core 11 is subjected to a step stripping process, and each layer is exposed in order from the tip side. Each superconducting conductor layer 112 (112-1, 112-2, 112-3) is a normal conducting connecting member electrically connected to each superconducting conductor layer 112 (112-1, 112-2, 112-3). 30 (30-1, 30-2, 30-3) are connected. Here, the normal conducting connection member 30 is arranged on the outer periphery of the superconducting conductor layer 112. A shielded connection terminal electrically connected to the cable shield layer 114 may be arranged on the outer periphery of the cable shield layer 114. In the present embodiment, the outer circumference of the electrically insulating layer 113 (113-1, 113-2, 113-3) arranged on the outer circumference of the superconducting conductor layer 112 (112-1, 112-2, 112-3). An electric field relaxation unit 15 such as a stress cone is arranged in the.

The heat insulating pipe 12 has a double pipe structure including an inner heat insulating inner pipe 121 and an outer heat insulating outer pipe 122. The heat insulating inner pipe 121 and the heat insulating outer pipe 122 preferably have a corrugated shape. The heat insulating inner pipe 121 and the heat insulating outer pipe 122 are each composed of, for example, a corrugated pipe (corrugated pipe) made of stainless steel (SUS).

The heat insulating inner pipe 121 accommodates the cable core 11 and is filled with a refrigerant (for example, liquid nitrogen) during operation. As a result, the superconducting conductor layer 112 is maintained in the superconducting state. The space between the heat insulating inner pipe 121 and the heat insulating outer pipe 122 is maintained in a vacuum state during operation for heat insulation.

As described above, the superconducting cable 10 has a configuration in which a superconducting conductor layer 112 and a heat insulating pipe 12 having a double structure consisting of a corrugated inner pipe 121 and a heat insulating outer pipe 122 are sequentially provided on the outer peripheral side of the former. It has become.

The heat insulating inner tube 121 is airtightly fixed to the inner peripheral portion of the shield energized portion, and the heat insulating outer tube 122 is airtightly fixed to the outer peripheral portion of the shield energized portion.
The inner accommodating piece 211 has a tubular shape and is an insulating tube made of an insulating material such as epoxy resin or fiber reinforced plastic (FRP). That is, the terminal portion of the superconducting cable 10 is housed in the insulating pipe which is the refrigerant tank 21.

The inside of the inner accommodating piece 211 communicates with the normal conducting connection member 30 through a through hole 344 (see FIG. 3) formed through the superconducting cable 10 in the extending direction (also referred to as “axial direction”). It is in a state.
The refrigerant tank 21 may be placed on a pedestal (not shown) arranged in the vacuum tank 22, for example. Refrigerant is circulated and supplied to the refrigerant tank 21 by a refrigerant circulation device (not shown) during operation. The inside of the heat insulating inner pipe 121 communicating with the refrigerant tank 21 is also filled with the refrigerant.

The outer accommodating piece 221 has a cylindrical shape having a gauze pipe portion 23 on the outer periphery, and is provided between the normal conduction connecting members 30 so as to accommodate the refrigerant tank 21. The outer accommodating piece 221 is made of an insulating material such as epoxy resin or FRP, and is airtightly fixed to the normal conductive connecting member 30.

The inside of the outer accommodating piece 221 is in a state of communicating with the normal conducting connection member 30 via slots 313, 313, 315 (see FIG. 3) formed so as to penetrate the superconducting cable 10 in the extending direction. ..
The shaving tube portion 23 is composed of, for example, a polymer shaving tube or a porcelain shaving tube. Here, it is assumed that the slab tube portion 23 is composed of a polymer slab tube.

The shaving tube portion 23 is formed, for example, by integrally providing a polymer coating on the outer peripheral surface of the insulating cylinder. The insulating cylinder is made of FRP (fiber reinforced plastic) having high mechanical strength. When the electric field relaxation unit 15 is attached to the outer surface of the superconducting cable 10 in the refrigerant tank 21, it is arranged around the electric field relaxation layer at a position surrounding the electric field relaxation unit. The polymer coating is made of a material having excellent electrical insulation performance, for example, a polymer material such as silicone polymer (silicone rubber), and a plurality of umbrella-shaped folds are formed on the outer peripheral surface so as to be separated from each other in the longitudinal direction. .. The inside of the squeeze pipe portion 23, that is, the inside of the vacuum tank 22, is evacuated during operation to be in a vacuum state.

The vacuum tank 22 composed of the normal conduction connecting member 30 and the outer accommodating piece 221 is evacuated by a vacuum pump (not shown) during operation and is held in a vacuum state. The space between the heat insulating inner pipe 121 and the heat insulating outer pipe 122 communicating with the vacuum tank 22 is maintained in a vacuum state.

FIG. 3 is a front view showing a connection portion between a normal conducting connection member and a superconducting cable in the terminal structure according to the embodiment of the present invention, and FIG. 4 is a front view showing the connecting portion of the terminal structure according to the embodiment of the present invention. It is a side surface which shows the connection part of a normal conduction connection member and a superconducting cable in the above. Further, FIG. 5 is a cross-sectional view showing a modified example of the conductive flange. FIG. 6 shows a current-carrying region in the normal conduction connecting member of the present embodiment, FIG. 6A is a plan view of the normal conducting connecting member, and FIG. 6B is a cross-sectional view taken along the line BB of FIG. 6A. In FIG. 6, the energized region of the normal conducting connection member is indicated by dots.

The normal conducting connection member 30 shown in FIGS. 3 to 6 is electrically connected to the terminal of the superconducting conductor layer located on the outer peripheral surface of the superconducting cable 10 inside the inner accommodating piece 211 (refrigerant tank 21).

The normal conductive connection member 30 electrically connects the superconducting cable 10 to the device on the room temperature side via the terminal portion 301.

The normal conducting connection member 30 is an inner pipe that is arranged on the outer periphery of the cylindrical contact portion 32 and the tubular contact portion 32 that is arranged in electrical contact with the outer periphery of the superconducting cable 10 and to which the inner accommodating piece 211 is fixed. It has a ring 34 and a plurality of conductive flanges 36 arranged on the outer periphery of the inner tube ring 34. The tubular contact portion 32 and the inner tube ring 34 form a cable connection portion that is electrically connected to the superconducting cable 10.

In the normal conducting connection member 30, the cylindrical contact portion 32, the inner tube ring 34, and the plurality of conductive flanges 36 are each formed of a conductive member and are electrically connected to each other. The inner tube ring 34 and the conductive flange 36 are relatively rotatable around the superconducting cable 10 with respect to the cylindrical contact portion 32 by a contactor.

The tubular contact portion 32 is fixed in close contact with the superconducting conductor layer on the outer periphery of the superconducting cable 10 on the inner peripheral surface. In the present embodiment, as shown in FIG. 4, the thickness of the inner tube ring 34 and the conductive flange 36 is longer in the extending direction of the superconducting cable 10.

A multi-contact 33, which is a contactor, is attached to the inner circumference of the inner pipe ring 34, and the tubular contact portion 32 is electrically connected via the multi-contact 33 while being slidable in the circumferential direction and the axial direction. It is fitted on the outside.

The inner tube ring 34 is a conductive member made of copper or the like in the shape of an annulus plate to which the opening end portion of the inner accommodating piece 211 is fixed on the front and back surfaces. In the inner pipe ring 34, a fixing hole 342 for fixing the inner accommodating piece 211 is formed on the outer peripheral portion, and the refrigerant is provided along the inner peripheral edge in the inner portion of the inner accommodating piece 211 airtightly fixed to the fixing hole 342. A plurality of through holes 344 through which the through holes pass are provided so as to penetrate in the thickness direction.
A multi-contact 35, which is a contactor that is electrically connected to a connection partner and is relatively movable, is attached to the outer periphery of the inner tube ring 34. A plurality of conductive flanges 36 are electrically connected to the outer periphery of the inner tube ring 34 via the multi-contact 35, and are laterally aligned in the axial direction and slidably fitted in the circumferential direction and the axial direction. ing.

Each of the plurality of conductive flanges 36 has a terminal portion 301, a slot portion 310, and a conductive portion 320 defined by the slot portion 310 and connecting the terminal portion 301 and the inner pipe ring 34. The conductive portion 320 connects the terminal portion 301 and the cable connecting portion (including at least one of the cylindrical contact portion 32 and the inner tube ring 34). The conductive portion 320 defined by the slot portion 310 may be formed on the inner tube ring 34.

Here, the conductive flanges 36 (36-1, 36-2) are annular conductive plates composed of two pieces formed mirror-symmetrically in opposite directions. The conductive flanges 36 (36-1, 36-2) are formed of, for example, a conductive material such as copper, and the terminal portion 301 is formed so as to protrude from a part of the outer peripheral surface. It is desirable that the thickness of one conductive flange is less than twice the skin depth determined by the energization conditions (material, frequency, temperature). By reducing the thickness of each conductive flange, it is possible to reduce the proportion of the non-energized region due to the skin effect during AC energization, that is, to increase the energized region even with the same cross-sectional area. Joule heat generation per unit can be reduced, and the amount of heat intrusion can be reduced. Here, the amount of heat penetration is represented by the sum of the conduction heat transferred from the room temperature or high temperature portion of the normal conduction connecting member 30 to the low temperature portion and the Joule heat generation during energization.

In the conductive flange 36, the outer accommodating piece 221 (see FIG. 1) is airtightly fixed to the outer peripheral edge portion 362 on at least one surface of the front and back surfaces. A cover, which is the front end surface of the vacuum chamber 22, is airtightly fixed to the surface (here, the front end side surface) of the normal conducting connection member 30-1 shown in FIG.

The thickness of the conductive flange 36 is thinner than the thickness of the inner tube ring 34, and the thickness of the two pieces is substantially the same as the thickness of the inner tube ring 34. Since the conductive flanges 36-1 and 36-2 of the present embodiment have the same configuration, they are configured to have the same thickness.

The slot unit 310 has a plurality of slots 311, 313, and 315.

In the slot portion 310, the length of the conductive portion 320 between the terminal portion 301 and the contact portion between the superconducting cable 10 of the tubular contact portion 32 is different from that of the terminal portion 301 and the superconducting cable 10 of the tubular contact portion 32. The conductive portion 320 is defined so as to be longer than the straight line connecting the contact portions of the above.

In the present embodiment, the slots 311, 313, and 315 have a concentric and different diameter missing circle (a shape obtained by cutting a part of the circle with a straight line). Of the slots 311, 313, and 315, adjacent slots that are concentric and have different diameters correspond to the first slot and the second slot.

The end portion 311a that sandwiches the missing circle portion in the slot 311 on the outermost peripheral side is positioned at a position that overlaps with the terminal portion 301 in the radial direction.

In these plurality of slots 311, 313, 315, adjacent slots having different diameters sandwich a concentric end portion 311a sandwiching the missing circle portion in the slot 311 and an end portion 313a sandwiching the missing circle portion in the slot 313. It is placed in position. Further, in slots 313 and 315 adjacent to each other with different diameters, the end portion 313a sandwiching the missing circle portion of the slot 313 and the end portion 315a sandwiching the missing circle portion in the slot 315 are arranged at positions sandwiching the concentricity.

As shown in FIG. 4, the conductive flanges 36-1 and 36-2 thus configured are arranged on the outer peripheral surface of the inner tube ring 34 at intervals G apart from each other. In the present embodiment, the insulating material 363 is provided on the outer peripheral edge portion and the inner peripheral edge portion of the facing surfaces of the conductive flanges 36-1 and 36-2. The conductive flanges 36-1 and 36-2 can be brought into contact with each other through these insulating materials. As a result, the conductive flanges 36-1 and 36-2 can be slid simultaneously in the axial direction without being electrically connected.

When the conductive flanges 36-1 and 36-2 shown in FIG. 4 are arranged without being separated from each other, at least a part (for example, for example) of the conductive portion included in each of the conductive flanges 3601 and 3602 as shown in FIG. The conductive portions 320) defined by the slots 311, 313, and 315 may be arranged with a gap G0. FIG. 5 is a cross-sectional view showing a modified example of the conductive flange, and the normal conductive connecting member 300 shown in FIG. 5 differs only in the configuration of the conductive flange in the configuration of the normal conductive connecting member 30.

The conductive flanges 3601 and 3602 of the normal conductive connecting member 300 are arranged between the outer peripheral portion and the inner peripheral portion (the portion to which the multi-contact 35 is connected) in the configuration of the conductive flanges 36-1 and 36-2, and are slots. The conductive portions 3200 defined by 311, 313, and 315 are formed so as to have a gap G0 in the axial direction. As a result, the conductive flanges 3601 and 3602 are in close contact with each other in the axial direction between the outer peripheral portion and the inner peripheral portion in a state where the conductive portion 3200 portion corresponding to the conductive portion 320 is separated from each other by a gap G0. In the energizing flanges 3601 and 3602 having this configuration, when energized from a terminal portion (not shown) projecting from the outer peripheral surface of the outer peripheral portion, the conductive portion 3200 is separated in the axial direction by the skin effect on the front and back surfaces. A current flows through each of them, and it is possible to reduce the amount of heat invading the superconducting cable 10 from the outside while ensuring a more suitable current-carrying capacity than a single conductive flange.

FIG. 6 shows a current-carrying region in the normal conduction connecting member 30 of the present embodiment, FIG. 6A is a plan view of the normal conducting connecting member, and FIG. 6B is a sectional view taken along line BB of FIG. 6A.

In the normal conducting connection member 30 shown in FIG. 6, a plurality of conductive flanges 36-1 and 36-2 are arranged on the outer circumference of the cylindrical contact portion 32 connected to the superconducting cable 10 via an inner tube ring 34, and these are arranged. The superconducting cable 10 and the terminal portion 301 are made conductive via the above.

As described above, in the present embodiment, since the two conductive flanges are provided, it is possible to obtain a required cross-sectional area while having the slots. The limit thickness of the conductive flange that can be machined for the slot is about 40 mm, but it can be made thicker than this.

Further, in the case of alternating current energization, the energization region is not reduced due to the skin effect as compared with the conventional configuration in which energization is performed through one flange.

Therefore, when connecting the superconducting cable 10 and the normal conducting portion, it is possible to reduce the amount of heat invading the superconducting cable from the outside while ensuring a suitable energizing capacity.

(Modification example 1)
FIG. 7 is a side view showing a modified example of the normal conducting connection member in the terminal structure of the superconducting cable according to the embodiment of the present invention. FIG. 8 is a side sectional view showing a modified example of the normal conducting connection member in the terminal structure of the superconducting cable according to the embodiment of the present invention. FIG. 9 is a diagram showing an energized region in the modified example 1 of the normal conductive connecting member, FIG. 9A is a plan view showing an energized region of the normal conductive connecting member as the modified example 1, and FIG. 9B is a plan view of FIG. 9A. It is a cross-sectional view taken along the line CC. In FIG. 9, the energized region of the normal conducting connection member is indicated by dots.

The normal conductive connecting member 30A shown in FIGS. 7 and 8 has the same basic configuration as the normal conductive connecting member 30, and differs only in the number of conductive flanges 36A. Therefore, the normal conductive connection member 30A has the same reference numerals as those of the normal conductive connecting member 30, and the description thereof will be omitted.

That is, the normal conducting connection member 30A is arranged on the outer periphery of the cylindrical contact portion 32 and the tubular contact portion 32 which is arranged in electrical contact with the outer periphery of the superconducting cable 10, and the inner accommodating piece 211 is fixed. It has an inner tube ring 34 and a plurality of conductive flanges 36A arranged on the outer periphery of the inner tube ring 34.

Similar to the normal conductive connection member 30, the normal conductive connecting member 30A includes between the tubular contact portion 32 and the inner pipe ring 34, and the inner pipe ring 34 and a plurality of conductive flanges 36A (36-3, 36-4, It is electrically connected to 36-5) via contacts (multi-contacts 33, 35A) that are relatively rotatable and electrically connected. As a result, the superconducting cable 10 is connected during cooling. Even if the (specifically, the superconducting conductor layer) is thermally contracted and contracts in the axial direction or moves in the twisting direction, the inner tube is provided by the tubular contact portion 32 that moves following the thermal contraction. The ring 34 and the plurality of conductive flanges 36A can be maintained in a state of being electrically connected to the superconducting cable 10 without being moved and damaged.
Further, on the outer peripheral surface of the inner tube ring 34 surrounding the cylindrical contact portion 32 fixed to the outer circumference of the superconducting cable 10, three conductive flanges 36A electrically connected via the multi-contact 35A are superconducting cables. It is provided so as to be relatively rotatable around 10 and at intervals G1 from each other.

Each of the conductive flanges 36A (36-3, 36-4, 36-5) of the present embodiment has an annulus plate shape similarly made of the same material. Each of the conductive flanges 36A (36-3, 36-4, 36-5) has a slot portion 310 formed between the terminal portion 301 and the cable connecting portion (inner tube ring 34 and cylindrical contact portion 32). Provided is a conductive portion 320 that connects the terminal portion 301 and the cable connecting portion (cylindrical contact portion 32, inner tube ring 34).

In the conductive flange 36A, the region where the conductive portion 320 is formed may be formed thinner than the outer edge portion and the inner edge portion of the conductive flange 36A. That is, the facing surfaces of the conductive flanges 36-3, 36-4, 36-5 facing each other in the axial direction may have a shape in which a recess is formed in the center. In the conductive flange 36A, an insulating material (not shown) is provided on the outer peripheral edge portion and the inner peripheral edge portion of each conductive flange.

In the conductive flange 36A, an insulating material is interposed at at least one of the outer edge portion and the inner edge portion of the facing surfaces facing each other in the axial direction. As a result, the conductive flanges 36-3, 36-4, 36-5 can be slid simultaneously in the axial direction without being electrically connected.

As shown in FIGS. 8 and 9, the conductive flange 36A (36-3, −36-4, 36-5) is composed of three pieces, and the total thickness is substantially the same as that of the embodiment. As shown in 9, it is possible to further prevent a decrease in the energizing capacity due to the skin effect. Therefore, when connecting the superconducting cable and the normal conducting portion, it is possible to reduce the amount of heat invading the superconducting cable from the outside while ensuring a suitable energizing capacity.

Further, in the terminal structure 1 of the present embodiment, a superconducting cable 10 having a plurality of layers of superconducting conductor layers, particularly a three-phase superconducting cable, is used, but the present invention is not limited to this, and the superconducting conductor layer is a single-phase superconducting cable. A configuration using the cable 10 may be used.
Further, the shape of the slot portion 310 may be formed in any shape, and the superconducting cable 10 is formed by increasing the distance between the terminal portion 301 and the inner tube ring 34 in a knot-folded shape, a frame shape, a spiral shape, or the like. The distance to the connected tubular contact portion 32 may be longer than the straight line from the center to the end of the normal conducting connection member.

In the normal conductive connection member 30 and the first modification of the embodiment, the outer periphery of the conductive flanges 36-1 to 36-5 is covered with a heat insulating material 7 such as glass wool (shown by a chain double-dashed line in FIGS. 6A and 9A). You may do so. This makes it possible to further prevent heat from entering the outer flange 36 from the outside. The outer circumferences of the conductive flanges 3601 and 3602 shown in FIG. 5 may also be covered with a heat insulating material such as glass wool.

[Example 1]
The terminal structure shown in FIG. 1 was manufactured by using a material in which the normal conductive connection member 30 shown in FIG. 3 was silver-plated on oxygen-free copper. The normal conducting connection member 30 has a configuration in which two energizing flanges 36 having a cross section thickness of 19.5 mm at the energizing portion (corresponding to the thickness of the conductive portion 320 portion) are provided on the outer periphery of the inner tube ring 34 with a 1 mm gap.

[Example 2]
In the same configuration as in Example 1, only the conductive flange was changed, and the terminal structure shown in FIG. 9 was manufactured as Example 2 with a cross section of the energized portion of 12.7 mm × 3 sheets (stacking interval: 1 mm).

[Comparative Example 1]
In the same configuration as in Example 1, only the conductive flange was changed, and the current-carrying portion had a cross section of 40 mm × 1 piece, and was manufactured as Comparative Example 1.

When each of Examples 1 and 2 and Comparative Example 1 was energized at an energizing current AC3000A (effective value) and a frequency of 60Hz and the amount of heat penetration was measured, Example 1 was 315W and Example 2 was 298W. In Comparative Example 1, it was 346W. The amount of heat penetration was measured by the calorimetric method.
As a result of the measurement, it was found that the heat penetration amount of Example 1 was 91% with respect to Comparative Example 1 and that of Example 2 was 86% with respect to Comparative Example 1, which was reduced as compared with Comparative Example 1. ..

Although the invention made by the present inventor has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment and can be changed without departing from the gist thereof.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Terminal structure 10 Superconducting cable 11 Cable core 12 Insulation pipe 20 Cryogenic container 21 Refrigerant tank 22 Vacuum tank 23 Gable pipe part 30, 30A, 300 Normal conduction connection member 32 Cylindrical contact part (cable connection part)
33, 35, 35A Multi-contact 34 Inner tube ring (cable connection)
36, 36-1, 36-2, 36-3, 36-4, 36-5, 36A, 3601, 3602 Conductive flange 111 Central cooling pipe 112 Superconducting conductor layer 113 Electrical insulation layer 114 Cable shield layer 115 Protective layer 121 Insulation Inner pipe 122 Insulated outer pipe 211 Inner accommodating piece 221 Outer accommodating piece 301 Terminal part 310 Slot part 311, 313, 315 Slot 320, 3200 Conductive part 342 Fixing hole 344 Through hole 362 Outer peripheral edge part 363 Insulation material 311a, 313a, 315a End Part G, G0, G1 Interval

Claims (8)

A member that is connected to a superconducting cable and electrically connects the superconducting cable to equipment at room temperature, and is a normal conducting connection member used for alternating current energization.
A cable connection that is electrically connected to the superconducting cable,
Has a terminal portion connected to the device, a conductive portion for continuously with the with the terminal portions cable connection, and a plurality of conductive flange comprising,
A normal conductive connecting member in which the thickness of each of the plurality of conductive flanges is less than twice the skin depth determined by the energization condition. At least a part of the conductive portions included in each of the plurality of conductive flanges are arranged at intervals.
The normal conductive connection member according to claim 1. The plurality of conductive flanges are spaced apart from each other.
The normal conductive connection member according to claim 1. An insulating material is disposed between the plurality of conductive flanges.
The normal conductive connection member according to claim 3. In each of the conductive flanges, the conductive portion is defined by a slot portion formed between the terminal portion and the cable connecting portion.
The normal conduction connecting member according to any one of claims 1 to 4. The slot portion has a plurality of concentric and different diameter missing circular slots, and the superconducting cable is connected to the concentric portion.
The normal conductive connection member according to claim 5. The plurality of slots include concentric and adjacent missing circular first and second slots of different diameters.
The end portion that sandwiches the missing circle portion in the first slot and the end portion that sandwiches the missing circle portion in the second slot are arranged at positions that sandwich the concentric portion.
The normal conductive connection member according to claim 6. The normal conductive connecting member according to any one of claims 1 to 7.
A superconducting cable connected to the normal conductive connecting member and
Have,
Terminal structure of superconducting cable.

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