JP2008130860A - Superconductive device, and current lead - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturized and easily manufactured current lead, applicable in a superconductive device which receives a plurality of superconductive instruments into a common vacuum heat insulating vessel and employs oxide superconductive material, and to provide a superconductive device employing the lead. <P>SOLUTION: The superconductive device is provided with a plurality of superconductive instruments 3, the vacuum heat insulating vessel 2 for receiving the superconductive instruments 3 and a current lead for connecting a power supply 30 to the superconductive instruments 3. The current lead is provided with a usual state conductive current lead 1a, which penetrates the vacuum heat insulating vessel 2 and consisting of a right conductive metal while being common with a plurality of superconductive instruments, a high-temperature terminal side electrode 11a, consisting of the right conductive metal and arranged in the vacuum vessel while the usual state conductive current lead 1a is connected thereto, and a plurality of oxide superconductive bodies 10, connecting the high-temperature side electrode 11a and a plurality of superconductive instruments 3 respectively. The oxide superconductor 10 is constituted of an oxide superconductive bulk material or an oxide superconductive thin film tape filament. The high-temperature terminal side electrode 11a can have a plurality of branches with a plurality of oxide superconductors 10 connected respectively thereto. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a current lead using an oxide superconductor and a superconducting device having such a current lead.

  The greatest feature of the superconducting phenomenon is that the electric resistance of the superconducting conductor becomes zero at the critical temperature, so that no heat is generated even when energized, so that a large current can flow without loss. A superconducting magnet device used in a superconducting power storage system is a typical device that applies this superconducting phenomenon.

  In the conventional typical superconducting magnet device, the superconducting magnet is housed in a heat shield of a vacuum heat insulating container called a cryostat, and the superconducting magnet is cooled by a refrigerator attached to the vacuum heat insulating container (patent) Reference 1). This superconducting magnet device requires a current lead for supplying a current from a power source installed at room temperature to a superconducting magnet installed at a very low temperature. The current lead is connected to a normal current lead made of a highly conductive metal and a superconducting current lead made of an oxide superconductor. The current lead is structured to be cooled by a refrigerator or a cooling medium.

  In recent years, in a superconducting magnet system, a multistage magnet configuration system such as a multi- or hybrid configuration in which a plurality of magnets are housed in the same cryostat has been developed.

At the same time, development of high-temperature oxide superconducting conductors for application to superconducting magnets has been underway, and magnets using Bi-based oxide conductors have also been manufactured. In view of the application of next-generation magnets, an oxide superconducting thin film tape wire in which a thin-film Y-based oxide superconducting material of several μm is formed on a low heat conductive metal substrate of several hundreds of μm has been developed. The critical current value of the tape wire has a high performance of several hundred A.
JP 2004-111581 A

  Among superconducting magnet devices that have been developed in recent years, there are those composed of superconducting coils that carry a large current, and the superconducting magnet device used in the superconducting power storage system is one of them. .

  In a multistage magnet configuration system composed of several magnets, a current lead system is required for each magnet, which complicates the system and increases costs. Moreover, when it accommodates in the same container, the problem of installation space arises.

  Oxide superconducting current leads using Bi-based oxide superconducting conductors and Y-based bulk oxide superconducting conductors developed so far and applied to various devices are relatively easy to handle There are few oxide current leads that can handle large currents, and current oxide superconducting current leads are often expensive. Further, development of a thin film Y-based oxide superconducting material as a next-generation wire is underway, and applications other than superconducting magnets are also considered. However, this conductor has a problem that thin film deterioration due to a thin film state and bonding with a different material such as a highly conductive metal body is difficult.

  The present invention has been made in view of the above circumstances, and is applicable to a superconducting device in which a plurality of superconducting devices are housed in a common vacuum heat insulating container, and is a small and easily manufactured current using an oxide superconducting material. An object is to provide a lead and a superconducting device using the lead.

  In order to achieve the above object, a superconducting device according to the present invention includes a plurality of superconducting devices that are cooled to a low temperature and placed in a superconducting state, a vacuum insulation container that accommodates the plurality of superconducting devices in common, and the vacuum In the superconducting apparatus, the current lead penetrating the vacuum container, the power supply connecting the power supply outside the heat insulation container and the plurality of superconducting equipment, and having a current lead electrically insulated from the vacuum insulation container. The plurality of normal conductive current leads made of a highly conductive metal, common to the plurality of superconducting devices, and the conductive current lead made of a highly conductive metal and connected to the normal conductive current lead. And a plurality of oxide superconducting conductors that individually connect the high temperature end side electrode and the plurality of superconducting devices.

  Further, the current lead according to the present invention is connected to a plurality of superconducting devices housed in a common vacuum insulation container, cooled to a low temperature and placed in a superconducting state, and a power supply outside the vacuum insulation container, A vacuum heat insulating container is an electrically insulated current lead made of a highly conductive metal that penetrates the vacuum container, a normal conductive current lead portion common to the plurality of superconducting devices, and a highly conductive metal. The high temperature end side electrode common to the plurality of superconducting devices, which is arranged in the vacuum vessel and connected to the normal current lead portion, and the high temperature end side electrode and the plurality of superconducting devices individually. And a plurality of oxide superconducting conductors to be connected.

  ADVANTAGE OF THE INVENTION According to this invention, it can apply in the superconducting apparatus which accommodated the several superconducting apparatus in the common vacuum heat insulation container, and it is a superconducting which employ | adopted the small and easy current lead using an oxide superconducting material, and this An apparatus can be provided.

  Embodiments of a superconducting device according to the present invention will be described below with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is an elevational view showing a current lead and its periphery according to a first embodiment of the present invention. As shown in this figure, a plurality of superconducting devices (for example, superconducting magnets) 3 are accommodated in one common vacuum heat insulating container 2. A power supply 30 for supplying current to the superconducting device 3 is disposed outside the vacuum heat insulating container 2. A current introduction terminal 8 is disposed through the upper portion of the vacuum heat insulating container 2, and the normal current lead 1 a in the vacuum heat insulation container 2 and the power supply 30 are electrically connected via the current introduction terminal 8. The normal current lead 1a is made of a highly conductive metal. The normal current lead 1 a and the power supply 30 are electrically insulated from the vacuum heat insulating container 2 by the current introduction terminal 8.

  In the vacuum heat insulating container 2, the lower end of the normal conduction current lead 1a is connected to the high temperature end side electrode 11a. The high temperature end side electrode 11 a is a bar shape extending in the horizontal direction, is made of a highly conductive metal, and is disposed above the superconducting device 3. A plurality of oxide superconductors 10 are connected to the high temperature end electrode 11a. The oxide superconducting conductors 10 extend in the vertical direction in parallel with each other, the upper ends thereof are connected to the high temperature end side electrodes 11a, and the lower ends are individually connected to the respective superconducting devices via the corresponding low temperature end side electrodes 11b. 3 is connected. The oxide superconducting conductor 10 is, for example, an oxide superconducting bulk material or an oxide superconducting thin film tape wire. In this embodiment, the oxide superconducting conductors 10 have the same shape and the same dimensions.

  A heat transfer plate 6 is attached to the high temperature end side electrode 11 a, and the heat transfer plate 6 is connected to the refrigerator 5 through an insulating plate 7. The refrigerator 5 is attached to the vacuum heat insulating container 2. The high temperature end side electrode 11 a is cooled by being thermally connected to the refrigerator 5 through the heat transfer plate 6 and the insulating plate 7. The superconducting device 3 may be cooled by the refrigerator 5 or the superconducting device 3 may be directly cooled by another refrigerator (not shown).

  According to this embodiment, current is supplied from the power supply 30 of one system, and this is branched inside the vacuum heat insulating container 2, so that the apparatus can be reduced in size, manufactured easily, and the cost is reduced. .

[Second Embodiment]
FIG. 2 is an elevation view showing a current lead according to the second embodiment of the present invention. In this embodiment, a plurality of slits (notches) 12 are formed in the lower portion of the high temperature end electrode 11a, and each portion sandwiched between two adjacent slits is a protrusion 32 extending downward. One oxide superconductor 10 is connected to the lower end of each protrusion 32. In this embodiment, the protrusions 32 have the same shape and the same dimensions. The structure of other parts is the same as that of the first embodiment.

  According to this embodiment, in addition to the operations and effects of the first embodiment, the current flowing through each superconducting device 3 can be made uniform. That is, since each protrusion part 32 of the high temperature end side electrode 11a is mutually the same shape and the same dimension, the electric current which flows into each protrusion part 32 is equalized. This is because, in the superconducting portion, the electric resistance becomes zero regardless of the shape thereof, and the ratio of the electric resistance at each protrusion 32 where the current branches in the high temperature end electrode 11a is the current distribution ratio. This is due to the dominant influence.

[Third Embodiment]
FIG. 3 is an elevation view showing a current lead according to the third embodiment of the present invention. This embodiment is a modification of the second embodiment, and the lengths L of the protrusions 32 of the high temperature end side electrode 11a are different from each other. In this embodiment, since the length L of each protrusion part 32 differs mutually, a difference arises in the electrical resistance of this part. That is, the electrical resistance increases as the length L of the protruding portion 32 increases. For this reason, an electric current becomes small, so that the length L of the protrusion part 32 is long.

  According to this embodiment, the distribution of the current flowing through each superconducting device 3 can be positively made uneven as necessary. In addition, in the example of FIG. 3, according to the difference in the length L of the protrusion part 32, the oxide superconductor 10 is shortened, so that L is large, but the electrical resistance of each oxide superconductor 10 is the length. Regardless, the length of the oxide superconducting conductor 10 may be the same or different.

[Fourth Embodiment]
FIG. 4 is an elevation view showing a current lead according to the fourth embodiment of the present invention, and FIG. 5 is a horizontal sectional view of the current lead of FIG. This embodiment is a modification of the second or third embodiment, and the lengths L of the protrusions 32 of the high temperature end side electrode 11a are equal to each other, but their thicknesses are different from each other. Thereby, the cross-sectional areas of the protrusions 32 are different from each other, and the electric resistance of this portion is thereby different. As a result, as in the third embodiment, the distribution of the current flowing through each superconducting device 3 can be actively made non-uniform as necessary.

[Fifth Embodiment]
FIG. 6 is an elevation view showing a current lead according to the fifth embodiment of the present invention. This embodiment is a modification of the second or third embodiment, and the lengths L of the protrusions 32 of the high temperature end side electrode 11a are equal to each other, but the protrusions 32 and the oxides connected thereto. The contact areas with the superconducting conductor 10 are different from each other. Thereby, the electrical resistance in each contact surface will differ. As a result, as in the third and fourth embodiments, the distribution of the current flowing through each superconducting device 3 can be actively made non-uniform as necessary.

[Other Embodiments]
Each embodiment described above is merely an example, and the present invention is not limited thereto.

  For example, in the fourth embodiment (FIGS. 4 and 5), the thicknesses of the protrusions 32 are different from each other. However, the thicknesses (cross-sectional areas) of the protrusions 32 only need to be different. Even if the widths of the protruding portions 32 in the arrangement direction are different from each other, the same effect can be obtained.

  Further, the features of the third, fourth, and fifth embodiments (FIGS. 3 to 6) can be combined. That is, for example, the length L and thickness of each protrusion 32 of the high temperature end electrode 11a, and further the contact area between each protrusion 32 and the oxide superconductor 10 may be variously changed and combined.

  In the above embodiment, a superconducting magnet has been described as an example of a superconducting device accommodated in a vacuum heat insulating container, but other superconducting devices may be used.

  Further, the vertical relationship in the description of the above embodiment is for convenience of description, and the present invention can be applied regardless of the direction of gravity.

1 is an elevation view showing a current lead and its periphery according to a first embodiment of the present invention. FIG. 5 is an elevation view showing a current lead according to a second embodiment of the present invention. FIG. 6 is an elevation view showing a current lead according to a third embodiment of the present invention. FIG. 9 is an elevation view showing a current lead according to a fourth embodiment of the present invention. FIG. 5 is a horizontal cross-sectional view of the current lead of FIG. FIG. 9 is an elevation view showing a current lead according to a fifth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Current lead 1a ... Normal conduction current lead 2 ... Vacuum insulation container 3 ... Superconducting magnet (superconducting equipment)
5 ... Refrigerator 6 ... Heat transfer plate 7 ... Insulating plate 8 ... Current introduction terminal 10 ... Oxide superconducting conductor 11a ... High temperature end side electrode 11b ... Low temperature end side electrode 12 ... Slit (notch)
30 ... Power source 32 ... Projection

Claims (7)

A plurality of superconducting devices that are cooled to a low temperature and placed in a superconducting state;
A vacuum insulation container for commonly storing the plurality of superconducting devices;
Connecting the power supply outside the vacuum insulation container and the plurality of superconducting devices, current leads electrically insulated from the vacuum insulation container;
In a superconducting device having
The current lead is
A normal conductive lead common to the plurality of superconducting devices, made of a highly conductive metal that penetrates the vacuum vessel; and
A high-temperature end-side electrode common to the plurality of superconducting devices, made of a highly conductive metal, arranged in the vacuum vessel and connected to the normal-current lead portion,
A plurality of oxide superconducting conductors individually connecting the high temperature end side electrode and the plurality of superconducting devices;
A superconducting device characterized by comprising:   The superconducting device according to claim 1, wherein the oxide superconducting conductor is made of an oxide superconducting bulk material or an oxide superconducting thin film tape wire.   The superconducting device according to claim 1, wherein the high temperature end side electrode has a plurality of branch portions to which the plurality of oxide superconducting conductors are connected.   4. The superconducting device according to claim 3, wherein lengths of the plurality of branch portions of the high-temperature end-side electrode are different from each other according to magnitudes of required currents of the plurality of superconducting devices.   5. The superconducting device according to claim 3, wherein thicknesses of the plurality of branch portions of the high-temperature end-side electrode are different from each other according to magnitudes of required currents of the plurality of superconducting devices. .   6. The contact area between the high temperature end electrode and the plurality of oxide superconducting conductors is different from each other according to the required current of each of the plurality of superconducting devices. The superconducting device according to any one of the above. A plurality of superconducting devices housed in a common vacuum insulation container and cooled to a low temperature and placed in a superconducting state are connected to a power supply outside the vacuum insulation container, and are electrically insulated from the vacuum insulation container. Current leads,
A normal conductive lead common to the plurality of superconducting devices, made of a highly conductive metal that penetrates the vacuum vessel; and
A high-temperature end-side electrode common to the plurality of superconducting devices, made of a highly conductive metal, arranged in the vacuum vessel and connected to the normal current lead portion,
A plurality of oxide superconducting conductors individually connecting the high temperature end side electrode and the plurality of superconducting devices;
Having a current lead.

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