JPH0955128A - AC superconducting cable - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an AC superconducting cable with low power transmission loss and good twisting and bending characteristics. A wire shield material (shielding member 1) is wound around the outer periphery of an electric insulating material by SZ winding,
When the electric insulating material 106 contracts, the wire shield material (shielding member 1) also contracts along with the contraction. Therefore,
Wire shield material (shielding member 1) and electrical insulation material 106
Since a gap does not occur between and, the transmission loss does not increase because tan δ does not increase, and even if twisting occurs, the twisting is absorbed and the twisting characteristic becomes good.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC superconducting cable, and more particularly to an AC superconducting cable with reduced transmission loss.

[0002]

2. Description of the Related Art Conventionally, an AC superconducting cable using a superconductor has been proposed as one of the measures for increasing the transmission capacity of AC power.

FIG. 6 is a sectional view of an example of a conventional AC superconducting cable. As shown in FIG. 6, in the AC superconducting cable 100, a heat insulating pipe outer pipe 101, a laminated heat insulating layer 102, and a heat insulating pipe inner pipe 103 are arranged in order from the outside, and a refrigerant flow channel 104 is provided inside the heat insulating pipe inner pipe 103. Are formed.

Inside the refrigerant passage 104, three cable cores C are arranged. The cable core C includes a shield layer (magnetic shield) 105 and an electric insulation layer 1 in order from the outside.
06, a superconducting conductor 107, and a former 108 are arranged, and a refrigerant passage 109 is formed inside the former 108.

Here, the shielding layer (magnetic shield) 10
The functions of 5 are as follows. That is, when a large current is transmitted to the AC superconducting cable 100, the influence of the magnetic field accompanying it is not exerted to the outside, and the eddy current loss caused by the low resistance of the adiabatic tube due to low temperature is prevented from increasing. This is because.

As the shielding layer 105 required to have such a function, conventionally, a superconducting tape wire has been dealt with by spirally winding it around the outer periphery of the cable core C.

[0007]

However, the conventional shield layer 105 formed by spirally winding the superconducting tape wire cannot follow the contraction / expansion of the cable core C, and thus the shield layer 105.
And a member inside thereof, a gap is generated, and as a result, t
There was a tendency that an δ became unstable and tan δ increased. Further, in the case of spiral winding, the twisting and bending characteristics of the cable core were not preferable.

[0008] Therefore, an object of the present invention is to provide an AC superconducting cable having a small power transmission loss and good twisting and bending characteristics.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 allows a refrigerant to pass through the inside of a tubular superconducting conductor and coats the outside of the superconducting conductor with an electric insulating material. In a superconducting cable for alternating current, comprising a magnetic shield layer on the outer circumference of the electrical insulating material, the magnetic shield layer is formed by winding a wire shield material in SZ winding.

According to the first aspect of the present invention, since the wire shield material is wound around the outer periphery of the electric insulating material by SZ winding, as shown in FIG.
When 6) shrinks, the wire shield material (shielding member 1
a) also contracts with the contraction. Therefore, the wire shield material (shielding member 1a) and the electric insulating material (electrical insulating layer 1)
Since a gap is not generated between (6) and (6), transmission loss does not increase because tan δ does not increase, and even if twisting occurs, the twisting bending is absorbed and the twisting bending characteristic is improved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the illustrated embodiments. Note that the same reference numerals are given to the already described portions, and redundant description is omitted.

1A and 1B show a cable core C1.
3 is a perspective view and a cross-sectional view of FIG. As shown in FIGS. 1 (A) and 1 (B), an SZ winding (corrugated winding) shield member 1 is attached to the outer periphery of the electric insulating layer 106, and the shield member 1 is pressed by a holding tape 2 so as not to be peeled off. Has been.

As the shielding member 1, as shown in FIG.
The members shown in (B), (C) and FIGS. 3 (A), (B) are preferable. That is, FIGS. 2A, 2B and 2C show the case where the shielding member is the tape 10 and the high temperature superconductor 12 is covered with silver 11 (FIG. 2B). Alternatively, any of Hastelloy 14 coated with high temperature superconductor 13 may be used.

3A and 3B show the case where the shielding member is the wire rod 20 or 20A, and the high temperature superconductor 2
It is preferable that 1 is covered with silver 22 (FIG. 3 (A)) or hastelloy 23 is covered with high temperature superconductor 24.

Next, the operation will be described. Consider a case where the cable core C1 contracts due to the low temperature of the refrigerant (eg, liquid nitrogen). In this case, as shown in FIG. 4, the cable core C
1 The shield member 1a on the surface (assuming one shield member for explanation) 1a contracts as the electric insulating layer 106 contracts, as indicated by the chain double-dashed line.

This contracted state will be further described with reference to FIGS. 5 (A) and 5 (B). That is, as shown in FIG. 5A, the electric insulating layer 106 contracts as indicated by the chain double-dashed line 106a. At this time, as described above, the shielding member 1 (not shown) also contracts as the electric insulating layer 106 contracts, so that no gap is generated between the electric insulating layer 106 and the shielding member 1. Therefore, no gap occurs, so ta
It is possible to reduce the transmission loss without increasing nδ. Further, when twisting and bending occur, as shown in FIG. 4, the acting force is canceled between the peaks and troughs of the adjacent shielding member 1a, so that the shielding member 1a is twisted even if twisting is applied. Is not affected.

In the conventional superconducting cable for alternating current, a shielding member wound in a "spiral" was used.
In this case, as shown in FIG.
, The shield member 110 cannot follow the contraction because there is no escape on the surface of the electric insulating layer 106, and a gap is created between the electric insulating layer 106 and the shield member 110. The inconveniences described above (increase in power transmission loss, deterioration in torsional bending characteristics) have occurred.

The SZ winding of the wire shield material described above has been conventionally proposed for use in, for example, a CV cable (for example, Japanese Laid-Open Patent Publication No. 5-166419), but this proposal prevents the cable from twisting. The purpose is not to prevent transmission loss as in the present invention.

[0019]

As described above, according to the present invention, a refrigerant is passed through the inside of a tubular superconducting conductor, the outside of the superconducting conductor is covered with an electric insulating material, and the outer periphery of the electric insulating material is magnetically shielded. In the AC superconducting cable including layers, the magnetic shield layer is formed by winding the wire shield material in SZ. Therefore, as shown in FIG. 4, when the electric insulating material (electrical insulating layer 106) contracts, the wire shield material ( The shielding member 1a) also contracts along with the contraction. Therefore, a gap does not occur between the wire shield material (shielding member 1a) and the electrical insulating material (electrical insulating layer 106), so that tan δ does not increase, so that transmission loss does not increase and twisting occurs. However, the twisted bending is absorbed and the twisted bending characteristics are improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a cable core of an example of an embodiment of the present invention, in which (A) is a perspective view and (B) is a sectional view.

FIG. 2 is a perspective view showing the appearance of a shielding member in the example of the embodiment, and FIGS. 2B and 2C are cross-sectional views when the constituent materials of the tape are different.

FIG. 3 is a perspective view showing a case where the shielding member in the example of the embodiment is a wire rod, and FIGS. 3A and 3B are different perspective views.

FIG. 4 is a perspective view for explaining the action of the shielding member in the example of the same embodiment.

FIG. 5 (A) is a sectional view for explaining the operation in the example of the embodiment, and FIG. 5 (B) is a sectional view for explaining the operation in the conventional example.

FIG. 6 is a cross-sectional view of a conventional AC superconducting cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shielding member 2 Holding tape 10 Tape which is a shielding member 20 Wire which is a shielding member

Claims (1)

[Claims] 1. A superconducting cable for alternating current, comprising: passing a refrigerant inside a tubular superconducting conductor; covering the outside of the superconducting conductor with an electric insulating material; and providing a magnetic shielding layer on the outer periphery of the electric insulating material. The superconducting cable for alternating current, wherein the magnetic shielding layer is formed by winding a wire shield material in SZ winding.