JPH11204324A - Superconducting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the dielectric strength to the ground of a superconducting apparatus and the dielectric strength of the apparatus at quenching, without having to increase the size of the apparatus as a whole. SOLUTION: A superconducting apparatus is constituted by arranging moduled superconducting reactor elements 3a, each of which incorporates at least an insulated tank 11, a coolant tank 12 housed in the tank 11, a reactor 14 which contains a coolant 13 and a superconducting material housed in the tank 12, a pair of bushings 15 and 16 which are provided pierced through the walls of the tanks 12 and 11 so as to electrically connect the reactor 14 to the outside, and an electrically insulating cooling path 17, which is formed airtightly pierced through the wall of the tank 11 to cool the coolant tank 12 in insulating oil 2, in such a state that the elements 3a are connected in series with each other. When the superconducting device is constituted in this way, the insulated tanks 11 and vacuum vessels which constitute parts of the modules need to exhibit only heat insulating functions. In other words, the insulator which covers the moduled superconducting elements functions as a member that ensures the dielectric strength of the device to ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting device, and more particularly to a superconducting device capable of improving withstand voltage without increasing the size of the whole.

[0002]

2. Description of the Related Art As is well known, most superconducting devices represented by a superconducting coil device accommodate a refrigerant tank in a heat insulating tank, and accommodate electric components including a refrigerant and a superconductor in the refrigerant tank. Further, in order to electrically connect the electric component and the outside, a pair of current introduction mechanisms are provided through the walls of the refrigerant tank and the heat insulating tank. Usually, the heat insulating tank is constituted so as to exhibit a heat insulating function mainly by a vacuum layer, and a current introducing mechanism of a bushing type is often used.

When electric components in such a superconducting device are provided in a high-voltage circuit, for example, in series, the center conductor of the bushing and the electric components are necessarily kept at the same potential as the high-voltage circuit. The container of the heat insulating tank exposed to the atmosphere is grounded. Therefore, the vacuum layer in the heat insulating tank is required to exhibit both a heat insulating function and an electric insulating function.

[0004] Among them, the electrical insulation function in the vacuum layer is evaluated by the discharge voltage inside the vacuum. It is known that the in-vacuum creeping discharge voltage increases as the creepage distance increases, but is not linear with respect to the creepage distance, and does not increase so much as compared with the rate of increase of the creepage distance. That is,
Since the change in the dielectric strength due to the creepage distance in a vacuum is generally a gradual less than the first power of the distance, a sufficiently long creepage distance must be secured as the circuit voltage increases.
There has been a problem that the entire device has grown rapidly.

When the superconductor undergoes normal conduction transition (quenching) for some reason, the superconductor instantaneously transitions to a resistor. Therefore, for example, when used in the form of a coil, a high voltage is applied between turns of the coil winding. In such a case, it is necessary to increase the distance between turns. However, for example, in a coil for the purpose of generating a magnetic field, increasing the distance between turns not only increases the size of the coil itself, but also reduces the current density of the entire coil, so the number of turns must be increased. There was a problem that it became larger and bigger.

[0006]

As described above, in the conventional superconducting device, it is necessary to increase the dielectric strength to ground of the superconducting component housed therein or to prevent dielectric breakdown during quench. However, there has been a problem that the entire apparatus is significantly increased in size and lacks applicability. Therefore, an object of the present invention is to provide a superconducting device which can solve the above-mentioned problems and can be sufficiently used even in a high-voltage circuit.

[0007]

In order to achieve the above object, in a superconducting device according to the present invention, at least a heat insulating tank, a refrigerant tank housed in the heat insulating tank, and a refrigerant tank housed in the refrigerant tank. Electrical components including a refrigerant and a superconductor, a pair of current introducing mechanisms provided through the walls of the refrigerant tank and the heat insulating tank to electrically connect the electric parts to the outside, and the heat insulating tank. A superconducting element, which is modularized and includes an electrically insulating cooling passage provided in an airtight manner through the wall of the above and provided for cooling the refrigerant tank, is disposed in the insulator.

In order to achieve the above object, a superconducting device according to a second aspect of the present invention includes at least a vacuum container, an electric component including a superconductor housed in the vacuum container, and the electric component and the outside. A pair of current introduction mechanisms provided through the wall of the vacuum vessel for electrical connection,
A modularized superconducting element including an electrically insulating cooling passage provided through the wall of the vacuum vessel in an airtight manner and used for cooling the electric component is disposed in an insulator.

[0009] In the superconducting device according to claims 1 and 2, the insulator covering the modularized superconducting element is:
An insulating oil or a high-pressure insulating gas that easily ensures a high creeping discharge voltage is preferable.

In order to obtain a necessary dielectric strength or a required current capacity, a plurality of superconducting elements modularized may be connected in series or in parallel in an insulator. In this case, the core wire of one current introduction mechanism in each module may be at the same potential as the wall of the heat insulating tank or the vacuum vessel. In the superconducting device according to claim 2, a vacuum is applied so as to surround the superconducting parts. A heat shield plate may be arranged in the container.

In the superconducting device according to the first and second aspects, since the modularized superconducting element is disposed in the insulator, the heat insulating tank and the vacuum vessel that are part of the module are:
It is only necessary to exert mainly the heat insulation function. That is, the insulator covering the modularized superconducting element functions as a member for securing the dielectric strength to ground. In this case, if insulating oil or insulating high-pressure gas is used as the insulator, a high creeping discharge voltage can be easily secured, so that the thickness of the insulator layer can be reduced. The overall size can be reduced.

Further, in the superconducting device according to the first and second aspects, since the modularized superconducting element is arranged in the insulator, one superconducting device is constituted by combining a plurality of modules in series or in parallel. By
Compatible with superconducting devices of various specifications. Furthermore, since each module has a predetermined dielectric strength,
By connecting these in series in an insulator, it becomes possible to add a dielectric strength, and a sufficiently large ground dielectric strength can be obtained. Further, when the superconducting components in each module are quenched, the voltage applied to both ends of the conductive portion of the device can be shared between the superconducting components, so that turn-to-turn dielectric breakdown, which tends to occur when quenched, can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a superconducting device according to an embodiment of the present invention, in which the present invention is applied to a superconducting reactor device.

In FIG. 1, reference numeral 1 denotes an outer container formed of a metal material. An insulating oil 2 as an insulator is accommodated in the outer container 1, and two modular superconducting reactor elements 3 a and 3 b are accommodated in the insulating oil 2 in a state of being connected in series. ing.

Each of the superconducting reactor elements 3a and 3b includes a vacuum vessel 11 made of stainless steel or the like to form a heat insulating tank, and a refrigerant tank 12 made of stainless steel or the like and housed in the vacuum vessel 11. The refrigerant 1 represented by the liquid helium stored in the refrigerant tank 12
3, a reactor 14 formed of a member including a superconducting wire and housed in a coolant tank 12 so as to be immersed in a coolant 13, and a coolant for electrically connecting the reactor 14 and the outside. Bushings 15 and 16 are provided as a pair of current introduction mechanisms provided through the chamber 12 and the wall of the vacuum vessel 11, and are provided airtightly through the wall of the vacuum vessel 11 to cool the refrigerant tank 12. Electrical insulation cooling channel 1
7.

The bushing 15 has one end of the center conductor 18 connected to one end of the reactor 14 and the center conductor 1.
The other end of 8 extends through the upper wall of the refrigerant tank 12 and the upper wall of the vacuum vessel 11 to a position between the upper wall of the vacuum vessel 11 and the upper wall of the outer vessel 1. Insulating materials 19 and 20 are attached to portions of the outer peripheral portion of the center conductor 18 that penetrate the upper wall of the refrigerant tank 12 and the upper wall of the vacuum vessel 11. Electrical insulation between the refrigerant tank 12 and the vacuum vessel 11 is ensured.

On the other hand, the bushing 16 has one end of the center conductor 21 connected to the other end of the reactor 14 and the other end of the center conductor 21 connected to the upper wall of the refrigerant tank 12 and the vacuum vessel 11.
And extends to a position between the upper wall of the vacuum vessel 11 and the upper wall of the outer vessel 1. An insulating material 22 is attached to a portion of the outer periphery of the center conductor 21 that penetrates the upper wall of the coolant tank 12, and the insulating material 22 provides electrical insulation between the center conductor 20 and the coolant tank 12. Is secured. That is, for the bushing 16, the center conductor 2
1 penetrates the upper wall of the vacuum vessel 11 directly and airtightly, so that the central conductor 21 and the vacuum vessel 11 are kept at the same potential.

The portion of the center conductor 18 of the bushing 15 in the superconducting reactor element 3a, which is located between the upper wall of the vacuum vessel 11 and the upper wall of the outer vessel 1, is provided with the upper wall of the outer vessel 1 insulated. It is connected to the center conductor 24 of the bushing 23 provided therethrough. Superconducting reactor element 3
The portion of the center conductor 21 of the bushing 16 in FIG. 3A located between the upper wall of the vacuum vessel 11 and the upper wall of the outer vessel 1 is connected to the center conductor of the bushing 15 At 18, the vacuum vessel 11
Is connected to a portion located between the upper wall of the outer container 1 and the upper wall of the outer container 1.

On the other hand, a portion of the center conductor 21 of the bushing 16 in the superconducting reactor element 3b, which is located between the upper wall of the vacuum vessel 11 and the upper wall of the outer vessel 1, insulates the upper wall of the outer vessel 1. Bushing 2 penetrated in the state
6 are connected to the center conductor 27.

The electrically insulating cooling passage 17 is formed of a member having electrical insulation and good thermal conductivity such as aluminum nitride. One end of the cooling passage 17 is in close contact with the upper wall of the refrigerant tank 12, and the other end is a vacuum. An electrically insulating good thermal conductor 28 provided so as to penetrate the upper wall of the container 11, and airtightness is secured between the penetrating portion of the electrically insulating good thermal conductor 28 and the vacuum container 11. And electrically insulating good thermal conductor 2
An annular electrically insulating heat insulator 29 for thermally insulating the space between the vacuum vessel 8 and the vacuum vessel 11 is provided.

The upper wall of the outer container 1 is electrically insulating and has a good thermal conductor 2
8 and a cryogenic refrigerator 30
Is arranged. The cryogenic refrigerator 30 is constituted by, for example, a regenerative refrigerator capable of cooling the final cooling stage to about 4K. And this cryogenic refrigerator 3
0 indicates that the last cooling stage is an electrically insulating good heat conductor 28;
Is attached to the upper wall of the outer container 1 so as to be in close contact with the end surface of the outer container 1. A partition wall 31 is provided around the cooling stage of the cryogenic refrigerator 30 and the above-mentioned electrically insulating heat insulator 29 to keep the surroundings of the cooling stage in a vacuum atmosphere and to suppress heat intrusion from the outside.

In FIG. 1, reference numeral 32 denotes a heat equalizing conductor for equalizing the temperature of the refrigerant tank 12 in each of the superconducting reactor elements 3a and 3b. This heat equalizing conductor 32
One end is in close contact with the refrigerant tank 12, the other end is airtightly penetrated through the side wall of the vacuum vessel 11, and has an electrically insulating heat insulating layer on the outer periphery. And each superconducting reactor element 3a, 3
In the assembled state of b, the end faces of the adjacent ones are brought into close contact so as to exhibit the function as a heat conductor.

The superconducting reactor device thus configured has a central conductor 24 of bushings 23 and 26 such that two reactors 14 are inserted in series in an electric circuit, for example.
27 is connected to an electric circuit, and the outer container 1 is used in a state of being grounded.

As described above, the insulating oil 2 which is an insulator that has won the modularized superconducting reactor elements 3a and 3b
Since it is arranged inside, the vacuum vessel 11 which is a part of the module only needs to exhibit only the heat insulating function. That is, the insulating oil 2 covering the modularized superconducting reactor elements 3a, 3b functions as a member for securing the insulation strength to the ground. When the insulating oil 2 is used as the insulating material, it is easy to secure a high creeping discharge voltage, so that the thickness of the insulating layer can be reduced, and downsizing of the entire apparatus can be realized in a state where the withstand voltage to the ground is sufficiently ensured.

Further, in this superconducting reactor device, a system in which modularized superconducting reactor elements 3a and 3b are connected in series in insulating oil 2 to constitute one device is adopted. Therefore, by selecting the number and combination of modules, it is possible to cope with superconducting reactor devices of various specifications.

Further, since each of the modules has a predetermined dielectric strength, it is possible to add the dielectric strength by connecting them in series in the insulating oil 2 and to obtain a sufficiently large dielectric strength to ground. Obtainable.

Further, the reactor 14 in each module,
In other words, when the superconducting parts quench, the bushing 2
Since the voltage applied between the central conductors 24 and 27 of the third and second conductors can be shared among the superconducting components, it is possible to prevent the inter-turn dielectric breakdown which is likely to occur when quenched.

FIG. 2 shows a superconducting device according to another embodiment of the present invention, and also shows an example in which the present invention is applied to a superconducting reactor device. In this figure, the same functional parts as in FIG. 1 are indicated by the same reference numerals. Therefore, a detailed description of the overlapping part will be omitted.

The superconducting reactor according to this embodiment differs from the previous embodiment in the configuration of modularized superconducting reactor elements 3a 'and 3b'. That is, in the superconducting reactor elements 3a 'and 3b' according to this example, the vacuum vessel 1 as the heat insulating tank is used without using the refrigerant and the refrigerant tank.
A reactor 14 as a superconducting component is housed in the reactor 1. Then, the reactor 14 is directly cooled to a temperature lower than the superconducting transition temperature by the cryogenic refrigerator 30 using the electrically insulating cooling path 17 as a medium.

Even in such a configuration, since the modularized superconducting reactor elements 3a 'and 3b' are arranged in the insulating oil 2 which is a superior insulator, the vacuum vessel which is a part of the module is provided. 11 only needs to exhibit only the heat insulating function. Therefore, the same effect as the example shown in FIG. 1 can be exerted.

In this case, a heat shield plate is arranged around the reactor 14, and the heat shield plate is cooled to a predetermined temperature by a cooling stage other than the last stage of the cryogenic refrigerator 30, and radiated to the reactor 14. The heat which is going to penetrate may be removed.

FIG. 3 shows a conceptual diagram of an application example in which a superconducting element is modularized. That is, in this example, for example, a dielectric strength of 1 kV and a conduction capacity of 600 A
By forming the superconducting reactor elements 3 modularized into 8 parallel in the x direction and 4 series in the y direction, a superconducting reactor device with a dielectric strength of 4 kV and a conduction capacity of 5 kA is configured.

In each of the above-described examples, the insulating oil 2 is used as an insulator for securing ground insulation, but an insulating gas of a predetermined pressure may be used. Also, the means for cooling the superconducting parts is not limited to the cryogenic refrigerator, and various methods can be adopted, such as connecting a cooling source and an object to be cooled with a heat pipe taking electrical insulation into consideration. Further, the present invention can be applied not only to the reactor but also to various superconducting devices.

[0034]

As described above, according to the present invention,
Without increasing the overall size, improve the ground insulation strength,
It is possible to prevent dielectric breakdown, which tends to occur when the superconducting component is quenched.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a superconducting device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a superconducting device according to another embodiment of the present invention.

FIG. 3 is a conceptual diagram of a superconducting device according to still another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer container 2 ... Insulating oil 3, 3a, 3b, 3a ', 3b' ... Modularized superconducting reactor element 11 ... Vacuum container as heat insulation tank 12 ... Refrigerant tank 13 ... Refrigerant 14 ... Reactor 15, 16, 23 , 26: bushing as a current introduction mechanism 17: electric insulating cooling path 18, 21, 24, 27 ... central conductor 25 ... connecting conductor 28: electric insulating good thermal conductor 29 ... electric insulating heat insulator 30 ... cryogenic Refrigerator 31 ... partition wall

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor ▲ Tsuru ▼ Kazuyuki Naga 1st Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu plant of Toshiba Corporation

Claims (4)

[Claims] At least a heat insulating tank, a refrigerant tank housed in the heat insulating tank, an electric component including a refrigerant and a superconductor housed in the refrigerant tank, and electrically connecting the electric component and the outside. A pair of current introduction mechanisms provided through the wall of the refrigerant tank and the heat insulating tank for connection, and electricity provided for airtightly penetrating the wall of the heat insulating tank and used for cooling the refrigerant tank. A superconducting device characterized by comprising a modularized superconducting element including an insulating cooling passage arranged in an insulator. 2. An electric part including at least a vacuum container, a superconductor housed in the vacuum container, and a wall penetrating the vacuum container for electrically connecting the electric part to the outside. A modularized superconducting element including a pair of provided current introduction mechanisms and an electrically insulating cooling passage provided through the wall of the vacuum vessel in an airtight manner and used for cooling the electric component is placed in an insulator. A superconducting device characterized by being arranged in a superconductor. 3. The superconducting device according to claim 1, wherein a plurality of said superconducting elements modularized are provided in said insulator so as to be connected in series or in parallel. 4. The superconducting device according to claim 1, wherein the insulator is an insulating oil or an insulating gas.