JP2000340420A - Superconducting current-limiting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a superconducting current-limiting device capable of satisfying both high withstand voltage characteristic and cooling characteristic in a part between a current-limiting coil and ground when the coil is used at a high voltage, or between current-limiting coils in the case that a plurality of the current-limiting coils are electrically connected. SOLUTION: This current-limiting device is provided with superconducting current-limiting coil units 1a, 1b, 1c, 1d formed of superconductors which are plurally arranged in vacuum and electrically connected with each other, a refrigerant vessel 10 which is constituted by alternately combining heat conducting members 2a, 2b, 2c, 2d and electric insulators 3a, 3b, 3c, 3d and stores refrigerant 7, and heat conducting members 5a, 5b, 5c, 5d which thermally connect the heat conducting members 2a, 2b, 2c, 2d and superconducting current-limiting coil units 1a, 1b, 1c, 1d and indirectly cool the superconducting current-limiting coil units 1a, 1b, 1c, 1d by using the refrigerant 7 in the refrigerant vessel 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a superconducting current limiting device using a superconducting current limiting coil, and more particularly to a cooling structure for a superconducting current limiting coil.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing the structure of a conventional superconducting current limiting device disclosed in Japanese Patent Application Laid-Open No. 63-66907. In the drawing, 6 is a vacuum vessel, 7 is a coolant such as liquid helium, 10 is a coolant vessel, 12 is a current limiting coil formed of a superconductor, and 13 is a coolant for cooling the current limiting coil 12 using the coolant 7. Piping, 14 is current limiting coil 1
This is an electrical insulator for cooling while electrically insulating the pipe 2 and the pipe 13.

Next, an outline of the cooling structure will be described. The refrigerant 7 moving through the pipe 13 as shown by the arrow in FIG. 4 cools the current limiting coil 12 via the electric insulator 14. When the current-limiting coil 12 is a metal-based superconductor for this cooling, liquid helium is usually used as the refrigerant 7. As a result, the superconductor of the current limiting coil 12 is cooled to a temperature below the critical temperature and enters a superconductive state, and the electric resistance of the current limiting coil 12 becomes zero. At this time, if the thermal resistance of the electric insulator 14 is large, the temperature of the current limiting coil 12 becomes higher than the above-mentioned temperature. Therefore, it is desirable to use a material having as small a thermal resistance as possible for the electric insulator 14. On the other hand, electrical insulators 14 of the same material
In order to reduce the thermal resistance, the thickness may be reduced as much as possible, but this may deteriorate the electrical insulation characteristics.

[0004] Members of the superconducting current limiting device, such as the vacuum vessel 6, the refrigerant vessel 10, and the pipe 13, are generally made of metal. Therefore, the current limiting coil 1
The insulation properties between the vacuum vessel 2 and the vacuum vessel 6 (withstand voltage characteristics between the current limiting coil and the ground) had to be secured by the electric insulator 14. Therefore, conventionally, when the above-described superconducting current limiting device is used at a high voltage, the withstand voltage characteristics have been enhanced by increasing the thickness of the electric insulator 14. However, as described above, when the thickness of the electrical insulator 14 is increased, the thermal resistance increases, and its cooling characteristics are extremely poor.

In particular, when two or more current limiting coils 12 are connected in series, the withstand voltage between the current limiting coils 12 also needs to be ensured by the electric insulator 14, which is the same problem as in the case between the above-described grounding. A point had arisen.

[0006]

Since the conventional superconducting current limiting device is constructed as described above, when a high voltage is used, it is necessary to obtain a high withstand voltage characteristic between the current limiting coil and the ground. There has been a problem that the cooling characteristics of the current limiting coil are deteriorated, and if the cooling characteristics are to be ensured, the withstand voltage characteristics are deteriorated. Further, with respect to the withstand voltage characteristics and the cooling characteristics between the current limiting coils when a plurality of current limiting coils are electrically connected (series, parallel, or a combination of series and parallel), the above current limiting coils There was the same problem as between the ground and the ground.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and electrically connects a plurality of current-limiting coils between a current-limiting coil and a ground when a high voltage is used. It is an object of the present invention to obtain a superconducting current limiting device capable of satisfying both high withstand voltage characteristics and high cooling characteristics between current limiting coils.

[0008]

SUMMARY OF THE INVENTION A superconducting current limiting device according to the present invention includes a superconducting current limiting coil unit formed of a plurality of superconductors arranged in a vacuum and electrically connected to each other, and a heat conductor. And an electrical insulator are alternately combined, and a refrigerant container that stores the refrigerant, thermally connects the heat conductor and the superconducting current limiting coil unit, and forms a superconducting current limiting coil unit by the refrigerant in the refrigerant container. And a heat conducting member for indirect cooling.

A superconducting current limiting device according to the present invention includes a superconducting current limiting coil formed of a plurality of superconducting conductors arranged in a vacuum and electrically connected to each other, a refrigerant container for storing a refrigerant, and a refrigerant. A heat conduction member for thermally connecting the refrigerant in the container and the superconducting current limiting coil unit and indirectly cooling the superconducting current limiting coil unit by the refrigerant in the refrigerant container.

A superconducting current limiting device according to the present invention is constituted by alternately combining a heat conductor and an electric insulator, and is mounted on each of the heat conductors and a refrigerant container for storing a refrigerant. And a connected superconducting current limiting coil unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a sectional configuration diagram showing a configuration of a superconducting current limiting device according to Embodiment 1 of the present invention. In the drawings, reference numerals 1a, 1b, 1c, and 1d denote current limiting coil units (superconducting current limiting coil units), and a superconducting current limiting coil formed by a winding of a superconductor and an electric insulation (not shown) covering the peripheral surface thereof. It is composed of the body. 2a, 2b, 2
c and 2d are heat conductive portions (heat conductors) of the refrigerant container 10, and are formed of a good heat conductive member such as copper or aluminum. Reference numerals 3a, 3b, 3c, and 3d denote electric insulating portions (electric insulators) of the refrigerant container 10, which are formed by an electric insulating member such as FRP. These heat conducting parts 2a, 2b, 2
c, 2d and the electrical insulation parts 3a, 3b, 3c, 3d
Each is joined by an adhesive or the like. Reference numeral 4 denotes a bottom surface of the refrigerant container 10 formed of a heat conductive member. 5a,
5b, 5c, 5d are current limiting coil units 1a, 1b, 1
It is a current-limiting coil cooling member (heat conductive member) for cooling c and 1d, and is formed of a good heat conductive member such as copper or aluminum. Reference numeral 6 denotes a vacuum container storing the above components and the inside thereof is kept in a vacuum, 7 denotes a refrigerant such as liquid helium stored in a refrigerant container 10, and 8 denotes a current limiting coil unit 1a, 1b, 1c, This is a lead for electrically connecting 1d. In the illustrated example, the current limiting coil units 1a,
The leads 1b, 1c and 1d are connected in series by the lead 8.

Next, an outline of the cooling structure will be described. Current limiting coil units 1a, 1 arranged in vacuum vessel 6
b, 1c, 1d are the heat conducting portions 2a, 2
b, 2c, 2d, current limiting coil cooling members 5a,
It is cooled to a superconducting state by the refrigerant 7 via 5b, 5c, 5d.

When this superconducting current limiting device is connected to a high voltage circuit, the current limiting coil units 1a, 1
A high voltage is applied to both ends of b, 1c and 1d. At this time,
Each of the current limiting coil units 1a, 1b, 1c, 1d is applied with a voltage of 1/4 of the voltage at both ends, and also between the current limiting coil units 1a, 1b, 1c, 1d and the ground such as the vacuum vessel 6 respectively. The need for electrical insulation arises.

Here, the refrigerant container 10 of the superconducting current limiting device according to the first embodiment includes the heat conducting portions 2a, 2b, 2c,
Since 2d and the electric insulation portions 3a, 3b, 3c, 3d are alternately combined, sufficient electric insulation between the current limiting coil units can be ensured. Also, as shown in the figure, the refrigerant container 10 and the vacuum container 6 are connected to the ground.
If electrical connection is made at the electrical insulation section 3a, sufficient electrical insulation can be ensured. Further, since the current limiting coil units 1a, 1b, 1c, 1d are electrically insulated as described above, the current limiting coil units 1a, 1b, 1c, 1
The electrical insulator in d is thinner than the conventional electrical insulator 14, and the creepage distance can be reduced. Since the liquid helium used as the refrigerant 7 has an electric insulation strength substantially equal to that in a vacuum, the electric insulation of the current limiting coil units 1a, 1b, 1c, 1d is not broken by the refrigerant 7.

In the first embodiment, the case where the number of the current limiting coil units is four is described. However, the number of the current limiting coil units may be any. The same effect can be obtained even if the current limiting coil unit is a single current limiting coil or a combination of current limiting coils in parallel or in series and parallel.

As described above, according to the first embodiment, the refrigerant container for storing the refrigerant is constituted by alternately combining the heat conductors and the electric insulators, and the cooling medium connected to each of the heat conductors Since the superconducting current limiting coil is cooled through the members, the current limiting coil is used between the current limiting coil when using at a high voltage and the ground, and when a plurality of current limiting coils are electrically connected. Between them, both high withstand voltage characteristics and cooling characteristics can be satisfied.

Embodiment 2 FIG. FIG. 2 is a sectional view showing a configuration of a superconducting current limiting device according to Embodiment 2 of the present invention. In the figure, 9a and 9b are current-limiting coil cooling members (heat-conducting members) for thermally connecting the refrigerant 7 and the current-limiting coil units 1a and 1b, and are made of a good heat-conducting member such as copper or aluminum. . Numeral 11 denotes a lid of the refrigerant container 10 for shutting off the refrigerant 7 from the vacuum, and the current limiting coil cooling members 9a, 9
b is penetrated. If the lid 11 is made of an electrically insulating member or made of metal in consideration of mechanical strength, the penetrating portions of the current limiting coil cooling members 9a and 9b are made of an electrically insulating member. The refrigerant container 10 is electrically insulated from the current limiting coil cooling members 9a and 9b.
In the illustrated example, the current limiting coil units 1a and 1b are connected in series by a lead 8. The other components in FIG. 2 are the same as those in FIG. 1, and thus are denoted by the same reference numerals and redundant description will be omitted.

Next, an outline of the cooling structure will be described. The current limiting coil units 1a and 1b are cooled by the refrigerant 7 via the current limiting coil cooling members 9a and 9b as in the first embodiment, and are maintained in a superconducting state. The current limiting coil cooling members 9a and 9b are arranged separately in a refrigerant 7 such as liquid helium. Thus, even if the superconducting current limiting device is connected to a high-voltage circuit and a high voltage is applied to both ends of each of the current limiting coil units 1a and 1b, as in the first embodiment, each of the current limiting coil cooling members Since 9a and 9b are electrically insulated by the refrigerant 7, electric insulation between the current limiting coil units 1a and 1b is also ensured. In addition, the refrigerant 7 ensures electrical insulation with respect to the ground. Further, as described above, the current limiting coil units 1a, 1
Since b is electrically insulated, the electric insulator in the current limiting coil units 1a and 1b can be thinner than the conventional electric insulator 14 and the creepage distance can be reduced.

In the second embodiment, the case where the number of the current limiting coil units is two has been described. However, the number of the current limiting coil units may be any. Further, the same effect can be obtained even if the current limiting coil unit is a single unit or a current limiting coil unit is combined in parallel or in series and parallel.

As described above, according to the second embodiment, since the superconducting current limiting coil is cooled by the cooling member spaced apart in the refrigerant, the current limiting coil for use at a high voltage is used. And the ground, and between current-limiting coils when a plurality of current-limiting coils are electrically connected, both high withstand voltage characteristics and cooling characteristics can be satisfied.

Embodiment 3 FIG. 3 is a sectional configuration diagram showing a configuration of a superconducting current limiting device according to Embodiment 3 of the present invention. In the figure, reference numerals 11a, 11b, 11c, and 11d denote current limiting coil units (superconducting current limiting coil units), which are electric insulations (not shown) covering the peripheral surfaces of the heat conducting portions 2a, 2b, 2c, and 2d of the refrigerant container 10. It consists of a body and a superconducting current limiting coil in which a superconductor is directly wound around each of its peripheral surfaces. These current limiting coil units 11a, 11b, 1
1 c and 11 d are electrically connected in series by a lead 8. The other components in FIG. 3 are the same as those in FIG. 1, and thus are denoted by the same reference numerals and redundant description will be omitted.

Next, an outline of the cooling structure will be described. Since the current limiting coil units 11a, 11b, 11c, and 11d do not pass through the cooling members described in the first and second embodiments, they can be cooled with high cooling efficiency. Further, the electrical insulation portions 3a, 3b, 3c, 3d of the refrigerant container 10
The current limiting coil units 11a, 11
Since b, 11c and 11d are electrically insulated, this superconducting current limiting device is connected to a high-voltage circuit and each of the current limiting coil units 11a, 11b,
Even if a high voltage is applied to both ends of 1c and 11d, electrical insulation between the current limiting coil units 11a, 11b, 11c and 11d is ensured. In addition, if the refrigerant container 10 and the vacuum container 6 are connected to the ground by the electric insulating portion 3a as shown in the figure, sufficient electric insulation can be ensured. further,
As described above, the current limiting coil units 11a, 11b, 11
Since c and 11d are electrically insulated, the electric insulator in the current limiting coil units 11a, 11b, 11c and 11d can be thinner than the conventional electric insulator 14.

In the third embodiment, the case where the number of current limiting coils is four is described, but the number of current limiting coils may be any.

As described above, according to the third embodiment, the refrigerant container for storing the refrigerant is constituted by alternately combining the heat conductor and the electrical insulator, and each of the heat conductors is provided with a superconducting current limiting coil. The high voltage resistance and cooling characteristics between the current limiting coil and ground when using at high voltage and between current limiting coils when electrically connecting a plurality of current limiting coils are provided. You can meet both.

[0025]

As described above, according to the present invention, a superconducting current limiting coil unit formed of a plurality of superconductors arranged in a vacuum and electrically connected to each other is provided. And a refrigerant container that stores the refrigerant, thermally connects the heat conductor and the superconducting current limiting coil unit, and indirectly connects the superconducting current limiting coil unit with the refrigerant in the refrigerant container. Since it has a heat conducting member for cooling, it is electrically connected between the current limiting coil and ground when using at high voltage, and a plurality of current limiting coils are electrically connected (in series, parallel, or combined in series and parallel). In this case, there is an effect that both the high withstand voltage characteristics and the cooling characteristics can be satisfied between the current limiting coils in the case where the current limiting coils are connected.

According to the present invention, a superconducting current limiting coil formed of a plurality of superconductors arranged in a vacuum and electrically connected to each other, a refrigerant container for storing a refrigerant, and a refrigerant in the refrigerant container And a heat conducting member for thermally connecting the superconducting current limiting coil unit and the superconducting current limiting coil unit indirectly with the refrigerant in the refrigerant container,
When used at high voltage, between the current limiting coil and the ground, and electrically connect a plurality of current limiting coils (series, parallel,
In addition, there is an effect that both the high withstand voltage characteristic and the cooling characteristic can be satisfied between the current limiting coils in the case of connecting in series or in parallel.

According to the present invention, a refrigerant container configured to alternately combine heat conductors and electric insulators to store a refrigerant, and a superconductor mounted on each heat conductor and electrically connected to each other. Since the current limiting coil unit is provided, between the current limiting coil and the ground when using at a high voltage, and a plurality of current limiting coils are electrically connected (serial, parallel, or series and parallel combined In such a case, there is an effect that both high withstand voltage characteristics and high cooling characteristics can be satisfied between the current limiting coils in the case of connection.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram showing a configuration of a superconducting current limiting device according to Embodiment 1 of the present invention.

FIG. 2 is a sectional configuration diagram showing a configuration of a superconducting current limiting device according to Embodiment 2 of the present invention.

FIG. 3 is a sectional configuration diagram showing a configuration of a superconducting current limiting device according to Embodiment 3 of the present invention.

FIG. 4 is a cross-sectional configuration diagram showing a configuration of a conventional superconducting current limiting device.

[Explanation of symbols]

1a, 1b, 1c, 1d, 11a, 11b, 11c, 1
1d Current-limiting coil unit (superconducting current-limiting coil unit), 2a, 2b, 2c, 2d Heat conduction part (heat conductor), 3a, 3b, 3c, 3d Electric insulation part (electric insulation), 5a, 5b, 5c , 5d, 9a, 9b Current-limiting coil cooling member (heat conduction member), 7 refrigerant, 10 refrigerant container.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenji Shimohata 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Takashi Kakiuchi 3-2-2 Nakanoshima, Kita-ku, Osaka-shi, Osaka No. Kansai Electric Power Co., Inc. (72) Inventor Seinosuke Uno 3-3-22 Nakanoshima, Kita-ku, Osaka-shi, Osaka F-term within Kansai Electric Power Co., Inc. 5G013 AA01 AA02 AA04 BA01 CA02

Claims (3)

[Claims] 1. A superconducting current limiting coil unit formed of a plurality of superconductors which are arranged in a vacuum and electrically connected to each other, and a heat conductor and an electrical insulator are alternately combined, and A refrigerant container that stores a refrigerant, a heat conductive member that thermally connects the heat conductor and the superconducting current limiting coil unit, and indirectly cools the superconducting current limiting coil unit by the refrigerant in the refrigerant container. A superconducting current limiting device comprising: 2. A superconducting current-limiting coil formed by a plurality of superconductors arranged in a vacuum and electrically connected to each other; a refrigerant container for storing a refrigerant; a refrigerant in the refrigerant container; A superconducting current limiting device thermally connected to the current limiting coil unit and indirectly cooling the superconducting current limiting coil unit by the refrigerant in the refrigerant container. 3. A superconducting current limiting coil which is constituted by alternately combining a heat conductor and an electric insulator and stores a refrigerant, and which is mounted on each of the heat conductors and electrically connected to each other. A superconducting current limiting device comprising a unit.