JPH1173824A - Superconducting cable termination - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a superconducting cable terminal portion capable of increasing an AC critical current. SOLUTION: In a superconducting cable terminal portion having a plurality of superconducting conductor layers 11, 12, 13 laminated concentrically via an insulating material, each superconducting conductor layer 11, 12, 13 is provided.
Are electrically extracted to the outside while being insulated from each other, and are connected to the impedance adjusting devices 41, 42, and 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal portion of a superconducting cable having an insulated multilayer conductor used in an alternating current, and more particularly, to a drawing of a conductor at the terminal portion.

[0002]

2. Description of the Related Art A superconducting cable is formed by spirally winding a large number of superconducting wires on a former (core: metal or plastic pipe, etc.) in multiple layers in order to transmit a large current. In general, a thin insulating layer is provided between the respective layers to obtain electrical insulation. Nevertheless, at the end of the superconducting cable, as shown in FIG.
The terminals 12 and 13 are electrically short-circuited at the ends, and are integrally connected to one lead conductor 51 of the terminal connection device by solder 52 and taken out in the air. In the figure, 14 and 53 are stress cones, 15 is a storage tube, 54 is a bushing, 55 and 56 are cooling containers, a refrigerant is injected into the cooling containers 55 and 56, and heat insulation is provided between the cooling containers 55 and 56. A layer (not shown) is provided.

[0003]

As described above, the multi-layered superconducting conductor layers 11, 12, electrically short-circuited at the terminating end are provided.
13 through which an alternating current is applied, the concentric superconducting conductor layer 1
Since the impedances of the outer layers 1, 12, and 13 are different from each other, most of the AC current flowing from the terminal portion flows through the outermost superconducting conductor layer 13 and almost no current flows through the inner superconducting layers 11, 12. Not flowing.

Here, a superconducting cable in which a plurality of superconducting wires are concentrically combined via an insulating material (hereinafter, referred to as a multilayer superconducting cable) will be described. For example, outer diameter 20
Each 100 m long multilayer superconducting cable in which a tape-shaped superconducting wire having a thickness of 0.2 mm and a width of 3 mm is spirally wound around three layers of 20 layers per layer through an insulating material around a former having a diameter of φ mm. According to calculations, the ratio of the current flowing through the superconducting conductor layer is outer layer: intermediate layer: inner layer = 7: 2: 1. The premise of this calculation is that the impedance of each of the outer, middle and inner superconducting conductor layers is 0.6 mΩ,
2.5 mΩ, 4.4 mΩ, these conductors are 0.1 m
It is assumed that they are collectively connected to the lead conductor with a connection resistance of about Ω. When a current flows through such a multilayer superconducting cable from a multilayer superconducting conductor layer that is electrically short-circuited at the terminal end, the current flowing from the terminal end shunts to each layer, and due to the difference in impedance described above, the outer layer: Middle layer: Inner layer =
Current is distributed in a 7: 2: 1 ratio. Assuming that the critical current Ic per superconducting wire is constant and 50 A, the outermost layer 2
Although 50 A / wire flows through the zero superconducting wire, the impedance flowing through the intermediate layer and the inner layer is different, so that the current flowing therethrough decreases, and the critical current value P flowing through the entire multilayer superconducting cable is reduced.
Is P = 50 × 20 × (1 + 0.28 + 0.15) = 1
430A. If the current uniformly flows through the superconducting wires of each layer, the critical current value Q is: Q = 50 × 20 × (1+
1 + 1) = 3000 A, the reduction rate of the AC critical current in the conventional multilayer superconducting cable is R = (Q−
P) / Q = (3000-1430) /3000=0.5
It becomes 2. As described above, when a current flows through the conventional terminal portion, the reduction rate R of the AC critical current in the multilayer superconducting cable is extremely large. Therefore, it is an object of the present invention to provide a terminating portion that allows a uniform alternating current to flow through all superconducting wires of a multilayer superconducting cable to increase the critical current for alternating current.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the invention according to claim 1 has a plurality of superconducting conductor layers stacked concentrically via an insulating material. In the superconducting cable terminal portion, each superconducting conductor layer is electrically drawn out to the outside while being insulated from each other, and connected to an impedance adjusting device. More specifically, as set forth in claim 2, the superconducting conductor layer has a concentric shape, is connected to a lead rod composed of a plurality of mutually insulated conductor parts, and is a terminal part of the superconducting cable that is pulled out, Further, as described in claim 3, the superconducting conductor layer is a terminal portion of the superconducting cable which is divided into a fan shape, connected to a lead rod composed of a plurality of conductor parts insulated from each other, and pulled out.

In the present invention, each superconducting conductor layer is electrically drawn out to the outside while being insulated from each other, but the insulation is sufficient if it is possible to ensure that the superconducting conductor layers do not come into contact with each other, and the insulation is high. There is no need to consider from.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram of one embodiment of a superconducting cable terminal according to the present invention. FIG.
In the above, the multilayer superconducting conductor 10 has a configuration in which three superconducting conductor layers 11, 12, and 13 are spirally wound from above on a former (for example, an aluminum corrugated tube) via an insulating material. Has become. Specifically, the superconducting conductor layers 11 to 13 are made of a tape-shaped superconducting wire material of 20 μm.
The book is formed by spirally winding. A connection ring 16 is attached to each of the ends of the superconducting conductor layers 11 to 13 to prevent the superconducting wire from being broken and to connect the superconducting wire to each of the superconducting conductor layers 11 to 13.
6 is also electrically connected with solder. The end portion of the multilayer superconducting conductor 10 is arranged in a terminal connection device 20 having the same number of lead conductors as the number of superconducting conductor layers 11 to 13, and the superconducting conductor layers 11 to 13 are connected to the lead conductor of the terminal connection device 20. 21 to 23, respectively. This connection is performed by welding the lead wire 40 to the connection ring 16. As the lead wire 40, aluminum, copper or a superconducting wire can be used. The lead conductors 21 to 23 of the terminal connection device 20 are coaxially configured with an insulating material interposed between the conductors. These lead conductors 21 to 23
Are drawn out to the atmosphere through the bushing 24, and constitute the terminal portions 21a to 23a in the atmosphere, respectively. Terminal 2
Reference numerals 1a to 23a denote lead wires or bus bars, respectively, connected to the impedance adjusting devices 41 to 43, and the impedance adjusting devices 41 to 43 are electrically collectively connected to the AC power supply system 44. In the present embodiment, the impedance adjusting devices 41 to 43 are configured by coil-shaped reactors. These impedance adjustment devices 4
1 to 43, each impedance adjusting device 41 to 41 is adjusted.
When the sum of the impedances of 43 and superconducting conductor layers 11 to 13 is made equal, the current flowing in each superconducting conductor layer 11 to 13 becomes uniform. . In FIG. 1, 1
4 and 25 are stress cones, 15 is a storage tube, 26 and 27
Denotes a cooling container, a refrigerant is injected into the cooling container 26, and a heat insulating layer (not shown) is provided between the cooling containers 26 and 27.

A tape-shaped superconducting wire having a thickness of 0.2 mm and a width of 3 mm is formed around a former having an outer diameter of 20 mm, as described above.
In the case of a multilayer superconducting cable having a length of 100 m, which is helically wound between three layers of 20 layers per layer via an insulating material, the impedance of the superconducting conductor layers 11 to 13 is 4.4 mΩ and 2.5 mΩ, respectively. , 0.6 mΩ, the impedances of the impedance adjusting devices 41 to 43 are set to 0.6 mΩ, 2.5 mΩ, 4.4 mΩ, respectively.
By doing so, the current flowing through the superconducting conductor layers 11 to 13 can be made uniform.

In the above embodiment, the impedance adjusting device is a reactor. However, a resistor can satisfy this function. In the case of a resistor, there is an advantage that it can be made more compact than a reactor. Further, it is also possible to combine the reactor and the resistor to form an impedance adjusting device. Further, in the above-described embodiment, the lead conductor is formed concentrically. However, as shown in FIG. 2, for example, for a multilayer superconducting cable having four superconducting conductor layers, the circular conductor is divided into four sectors. , Conductor 3
1 to 34, and the insulating material 35 may be interposed between the conductors 31 to 34.

[0010]

According to the present invention, a plurality of superconducting conductor layers stacked concentrically via an insulating material are electrically led out to the outside while being insulated from each other, and connected to an impedance adjusting device. Therefore, the impedance of each line including the superconducting conductor layer and the impedance adjusting device can be made equal. Accordingly, when these impedance adjusting devices are connected to the same AC power supply system, a current close to the critical current and equal to the critical current can flow in each superconducting conductor layer, so that the AC critical current of the multilayer superconducting cable can be increased. There is an excellent effect. .

[Brief description of the drawings]

FIG. 1 is a conceptual explanatory diagram of one embodiment of a superconducting cable termination portion according to the present invention.

FIG. 2 is a cross-sectional view of a lead conductor connected to the superconducting cable terminal portion.

FIG. 3 is a conceptual explanatory view of a conventional superconducting cable termination portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Multilayer superconducting conductor 11, 12, 13 Superconducting conductor layer 14, 25 Stress cone 15 Storage tube 16 Connection ring 20 Termination connection device 21, 22, 23 Leader conductor 21a, 22a, 23a Terminal part 24 Bushing 26, 27 Cooling vessel 40 Lead Lines 41, 42, 43 Impedance adjuster 44 AC power supply system

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Shoichi Honjo 4-1 Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside the Electric Power Technology Research Institute, Tokyo Electric Power Company (72) Shinichi Mukaiyama 2-6-1 Marunouchi, Chiyoda-ku, Tokyo No. 1 Inside Furukawa Electric Co., Ltd. (72) Inventor Naotaka Ichiyanagi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Hirokazu Tsubouchi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo No. 1 Inside Furukawa Electric Co., Ltd. (72) Inventor Kazutomi Miyoshi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd.

Claims (3)

[Claims] In a superconducting cable terminal portion having a plurality of superconducting conductor layers stacked concentrically via an insulating material, each superconducting conductor layer is electrically pulled out to the outside while being insulated from each other, A superconducting cable terminator connected to an impedance adjuster. 2. A superconducting cable terminal according to claim 1, wherein the superconducting conductor layer is formed in a concentric shape and is connected to a lead rod composed of a plurality of mutually insulated conductor parts and is drawn out. . 3. The superconducting conductor layer is divided into a fan shape and connected to a lead bar composed of a plurality of conductor portions insulated from each other.
2. The superconducting cable terminal according to claim 1, wherein the terminal is pulled out.