Joint applied to superconducting cable

Abstract

The utility model relates to a joint applied to a superconducting cable. The joint comprises a terminal assembly, a superconducting connecting piece and a fastening structure. The terminal assembly includes a cable mounting portion and a joint connecting portion. The superconducting connecting piece is provided with a plurality of layers of stacked superconducting strips welded on the terminal assembly, penetrates through a cable mounting part and a joint connecting part, and comprises a cable connecting end located at the cable mounting part and a conductor connecting end located at the joint connecting part, the superconducting strips in the cable connecting end are arranged in a first stepped structure, and the superconducting strips in the conductor connecting end are arranged in a second stepped structure; the end parts are arranged in a second step type structure in a superconducting tape of the superconducting cable. And the fastening structure is arranged at the joint connecting part and is used for rigidly connecting an external conductor. The stepped structure of the superconductive connecting piece can be electrically connected with the superconductive strip of the stepped structure formed at the end part of the superconductive cable in a one-to-one correspondence manner, so that the uniform distribution of current in the superconductive cable can be ensured, and the connection resistance between the superconductive cable and other conductors can be further reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of superconductivity, in particular to a joint used for superconducting cables. Background Art

[0002] Superconducting cables have the advantages of large capacity, low loss, energy conservation and environmental protection, and have been widely used in the power industry. In particular, round-core superconducting cables (Conductor on Round Core / High Flexible ReBCOcables) are widely used in large high-field magnets, AC operating magnets and compact power cable systems due to their small size, high current density, low AC loss and good bending flexibility.

[0003] The end-capping quality of superconducting cables directly impacts the current-carrying performance of the entire cable. Existing superconducting cable ends are typically encapsulated with copper terminals combined with solder. With this approach, current must first pass through the copper layer of the terminals before reaching the superconducting tape within the cable. Furthermore, current can only flow through the outermost layer of the cable tape into the inner layer, making it difficult to reduce the resistance of the cable joint and ensure even current distribution within the cable. Utility Model Content

[0004] The utility model provides a joint for superconducting cables. The joint is connected to the superconducting cable through a superconducting connector. The stepped structure of the superconducting connector can correspond one-to-one with the superconducting tape at the end of the superconducting cable, which can not only ensure the uniform distribution of current in the superconducting cable, but also further reduce the connection resistance between the superconducting cable and other conductors.

[0005] The utility model adopts the following technical solutions:

[0006] A joint for a superconducting cable comprises: a terminal assembly, comprising a cable mounting portion and a joint connecting portion integrally connected and located at both ends; a superconducting connector, comprising a multilayer stacked superconducting tape welded on the terminal assembly, passing through the cable mounting portion and the joint connecting portion, comprising a cable connection end located at the cable mounting portion and a conductor connection end located at the joint connecting portion, wherein the conductor connection end is used to connect an external conductor, the superconducting tape in the cable connection end being arranged in a first stepped structure, and capable of being paired and electrically connected with an end portion of the superconducting tape of the superconducting cable arranged in a second stepped structure; a fastening structure, the fastening structure being arranged at the joint connecting portion, the fastening structure being used to rigidly connect the external conductor.

[0007] In one embodiment, the number of first steps of the first stepped structure is greater than or equal to the number of second steps of the second stepped structure.

[0008] In one embodiment, the length of each first step in the first stepped structure is greater than or equal to the length of each second step in the second stepped structure.

[0009] In one embodiment, the superconducting cable comprises a round-core superconducting cable. When wound to the end, each layer of superconducting tape from the inner layer to the outer layer is at least one pitch away from the end, so as to form the second stepped structure at the end.

[0010] In one embodiment, a mounting groove is provided on the cable mounting portion, the superconducting connector is provided at the bottom of the mounting groove, and the superconducting cable can be arranged in the mounting groove.

[0011] In one embodiment, a depth of the installation groove is greater than an outer diameter of the superconducting cable.

[0012] In one embodiment, the superconducting tapes in the conductor connection ends are arranged in a third stepped structure.

[0013] In one embodiment, the outer conductor includes another joint for a superconducting cable; the joint connection portion and the joint connection portion in another joint for a superconducting cable can be rigidly connected in pair by the fastening structure, and the two third stepped structures corresponding to the two paired joint connection portions can be electrically connected to each other in pair.

[0014] In one embodiment, the lengths of the third steps of the third stepped structure are the same, and the lengths of the plurality of third steps equally divide the length of the conductor connection end.

[0015] In one embodiment, the superconducting connector is connected to the terminal assembly by high-temperature soldering.

[0016] The utility model has at least the following beneficial effects:

[0017] The joints used for superconducting cables can connect the superconducting cables to other conductors through superconducting connectors composed of multiple layers of superconducting tapes. At the connection between the superconducting connectors and the superconducting cable, the stepped structure of the superconducting connectors can be electrically connected one-to-one with the stepped superconducting tapes formed at the ends of the superconducting cables, which not only ensures uniform current distribution in the superconducting cable, but also further reduces the connection resistance between the superconducting cable and other conductors.

[0018] Furthermore, the conductor connection end also has a stepped structure. When connecting an external conductor, the external conductor can be electrically connected to the superconducting connector through the conductor connection end. Similarly, the current of the external conductor can also flow evenly into the superconducting connector and be evenly distributed to all superconducting tapes of the cable through the superconducting connector. It can also further reduce the connection resistance between the cable and other conductors, and has the advantage of higher connection efficiency.

[0019] Furthermore, the outer conductor includes another joint for a superconducting cable; the joint connection portion can be rigidly connected to the joint connection portion of another joint for a superconducting cable through the fastening structure, and the two third stepped structures corresponding to the two paired joint connection portions can be electrically connected to each other. That is, the two joints of the present application can achieve a low-resistance connection between the two superconducting cables. The corresponding layers of superconducting tape at the conductor connection ends in the joint connection portions of the two joints are crimped face-to-face, completing a low-resistance connection between the superconducting connectors of the two joints, thereby achieving a low-resistance connection between the superconducting cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 This is a schematic diagram of the specific structure of the joint in one embodiment of the present utility model;

[0023] Figure 2 This is a schematic diagram of the connection structure of a connector in one embodiment of the present invention;

[0024] Figure 3 Schematic diagram of the superconducting tape structure at the end of a round-core superconducting cable;

[0025] Figure 4 This is a schematic structural diagram of two connectors connected in one embodiment of the present invention.

[0026] Reference numerals:

[0027] 1. Terminal assembly; 11. Cable installation portion; 111. Installation slot; 12. Connector connection portion;

[0028] 2. Superconducting connector; 21. Cable connection end; 211. First step structure; 212. First step; 22. Conductor connection end; 221. Third step structure; 222. Third step;

[0029] 3. Fastening structure;

[0030] 4. Superconducting cable; 41. Second stepped structure; 411. Second step. DETAILED DESCRIPTION

[0031] To make the purpose, technical solutions, and advantages of the present invention more clear, the following is a clear and complete description of the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work are within the scope of protection of the present invention.

[0032] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the usual meanings understood by persons of ordinary skill in the field to which this utility model belongs. The words "first", "second", "third" and similar terms used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0033] Superconducting cables can include various types of superconducting cables, such as round-core superconducting cables, multi-core superconducting cables, tape-type superconducting cables, and stranded superconducting cables. The joints between existing superconducting cables are mostly copper terminals combined with solder for packaging. Under this packaging method, the current needs to pass through the copper layer of the terminal before reaching the superconducting tape in the cable, and the current can only be injected into the inner tape through the outermost tape of the cable. It is difficult to reduce the resistance of the cable joint and it is difficult to ensure uniform distribution of current in the cable. In response to the above technical problems, the present invention provides a joint for superconducting cables, which can connect the superconducting cable to other conductors through a superconducting connector composed of multiple layers of superconducting tapes. At the connection between the superconducting connector and the superconducting cable, the stepped structure of the superconducting connector can be electrically connected one-to-one with the stepped superconducting tape formed at the end of the superconducting cable, which can not only ensure the uniform distribution of current in the superconducting cable, but also further reduce the connection resistance between the superconducting cable and other conductors. The technical solution of the present invention is described in detail below with reference to specific examples.

[0034] Reference Figures 1 to 4 As shown, the present invention relates to a joint for a superconducting cable, comprising a terminal assembly 1, a superconducting connector 2, and a fastening structure 3. The terminal assembly 1 includes a cable mounting portion 11 and a joint connecting portion 12 integrally connected and located at both ends thereof. The cable mounting portion 11 is used to mount a superconducting cable 4, while the joint connecting portion 12 is used to electrically connect to other external conductors.

[0035] Superconducting connector 2 is attached to terminal assembly 1 using high-temperature solder. It consists of multiple layers of stacked superconducting tape, spanning terminal assembly 1 and extending through cable mounting portion 11 and connector portion 12. Superconducting connector 2 has a cable connection end 21 located in cable mounting portion 11 and a conductor connection end 22 located in connector portion 12.

[0036] The conductor connection end 22 is used to connect to an external conductor. The superconducting tape in the cable connection end 21 is arranged in a first stepped structure 211 and can be paired and electrically connected with the end of the superconducting tape in the superconducting cable 4 arranged in a second stepped structure 41 .

[0037] In this embodiment, the first stepped structure 211 is a step-like arrangement of the layers of superconducting tape at the cable connection end 21, arranged in ascending steps from the end away from the conductor connection end 22 toward the end closer to the conductor connection end 22. The second stepped structure 41 is a step-like arrangement of the layers of superconducting tape in the superconducting cable 4, arranged in descending steps toward the end thereof.

[0038] In this embodiment, the first step 212 of the first stepped structure 211 formed by the superconducting tape in the cable connection end 21 is an electrical connection surface. The first step 212 can be electrically connected to the second step surface 411 of the second stepped structure 41 in a one-to-one manner.

[0039] The fastening structure 3 is provided on the joint connection portion 12 , and the fastening structure 3 is used for rigidly connecting the external conductor.

[0040] In one embodiment, the number of first steps 212 of the first stepped structure 211 in the cable connection end 21 is greater than or equal to the number of second steps 411 of the second stepped structure 41 in the superconducting cable 4, so as to ensure that each layer of superconducting tape in the superconducting cable 4 can be respectively connected to the superconducting tapes of different layers above the superconducting connector 2. This not only ensures that the current in the superconducting cable is evenly distributed to each layer of superconducting tape, but also further reduces the connection resistance between the superconducting cable 4 and other conductors.

[0041] In this embodiment, the number of the first steps 212 of the first stepped structure 211 can be equal to the number of the second steps 411 of the second stepped structure 41 in the superconducting cable 4. When installing the superconducting cable 4, the first steps 212 of the first stepped structure 211 and the second steps 411 of the second stepped structure 41 can be connected one by one to achieve more accurate and convenient installation.

[0042] In one embodiment, the length of each first step 212 in the first stepped structure 211 of the cable connection end 21 is greater than or equal to the length of each second step 411 in the second stepped structure 41 of the superconducting cable 4. This ensures that each layer of superconducting tape in the cable 4 can contact the superconducting tape of different layers on the superconducting connector 2 over the largest area, thereby minimizing the resistance between the superconducting cable and the superconducting connector.

[0043] The superconducting cable 4 may include various types of superconducting cables, such as round-core superconducting cables, multi-core superconducting cables, tape-type superconducting cables, and twisted superconducting cables. In this embodiment, the round-core superconducting cable is taken as an example for explanation. For superconducting cables of other structural types, the adaptability of the joint can be adjusted according to the structural type of the superconducting cable.

[0044] Reference Figure 3 As shown, when the round-core superconducting cable is wound to the end, each layer of superconducting tape from the inner layer to the outer layer is at least one pitch away from the end, so as to form the second stepped structure 41 at the end.

[0045] In one embodiment, if Figure 3 As shown, when the round-core superconducting cable is wound, the ends of each layer of superconducting tape differ by one pitch, and the second steps 411 of the formed second stepped structure 41 are of the same length. This facilitates positioning of each layer of superconducting tape when installing the superconducting cable.

[0046] The second stepped structure 41 of the round-core superconducting cable can have two, three, or more layers. This embodiment uses three layers of superconducting tape as an example. For example, when using the connector of this embodiment, the end of the superconducting cable 41 is prepared for encapsulation. The superconducting tape at the end of the superconducting cable 41 is aligned with the electrical connection surfaces of the various layers of superconducting tape at the cable connection end 21. The various layers of superconducting tape at the end of the round-core superconducting cable 41 are welded to the various layers of superconducting tape at the cable connection end 21 using low-temperature soldering, and then encapsulated in the cable mounting portion 11. During subsequent use, the external conductor is electrically connected to the superconducting cable through the superconducting connector 2. Under the connection structure of the joint, the current flowing from the external conductor to the superconducting connector 2 can be evenly distributed to the superconducting tapes of different layers in the cable connection end 21. Since the superconducting tapes at the end of the superconducting cable 4 correspond one-to-one to the superconducting tapes of different layers in the cable connection end 21, the current can be evenly distributed to all the superconducting tapes of the superconducting cable 4, which not only ensures the uniform distribution of current in the superconducting cable 4, but also further reduces the connection resistance between the superconducting cable and other conductors, and has the advantage of higher connection efficiency.

[0047] Specifically, in this embodiment, to accommodate the three superconducting layers of superconducting cable 4, superconducting connector 2 needs to be formed with three steps, resulting in a total of four superconducting layers. In one embodiment, the superconducting tape in conductor connection end 22 forms a third stepped structure 221, which can be configured based on the structure of the external conductor to be connected. In this embodiment, the number of third steps 222 in third stepped structure 221 is the same as the number of first steps 212 in first stepped structure 211.

[0048] In one embodiment, the lengths of the third steps 222 of the third stepped structure 221 are the same, and the lengths of the plurality of third steps 222 equally divide the length of the conductor connection end 22. When two connectors are butt-jointed and crimped, the steps of the conductor connection ends 22 in the two connectors can be better aligned and crimped.

[0049] When connecting an external conductor, the external conductor can be electrically connected to the superconducting connector 2 through the conductor connection end 22. Similarly, the current of the external conductor can also flow evenly into the superconducting connector 2 and be evenly distributed to all superconducting tapes of the superconducting cable 4 through the superconducting connector 2. It can also further reduce the connection resistance between the superconducting cable 4 and other conductors, and has the advantage of higher connection efficiency.

[0050] In one embodiment, the fastening structure 3 includes four mounting holes, which are provided on the connector connection portion 12. The terminal assembly 1 is fixed by bolts. In alternative embodiments, the number of mounting holes may be greater or less, and the mounting holes may be through holes or threaded holes.

[0051] In one embodiment, if Figure 4 As shown, the outer conductor includes another joint for a superconducting cable; the joint connection portion 12 and the joint connection portion 12 in another joint for a superconducting cable can be rigidly connected by the fastening structure 3, and the two third stepped structures 221 corresponding to the two paired joint connection portions 12 can be electrically connected to each other. That is, a low resistance connection between two superconducting cables 4 can be achieved by the two joints in this application, as shown in FIG. Figure 4 The corresponding layers of superconducting tapes at the conductor connection ends 22 in the joint connection portion 12 of the two joints shown are crimped face to face one to one, thereby completing a low-resistance connection between the superconducting connectors 2 of the two joints, and further achieving a low-resistance connection between the superconducting cables 4.

[0052] In one embodiment, when the superconducting tape layers of the two joints are crimped one-to-one, a flexible metal, such as indium, can be filled on the crimped surfaces. At the same time, the fastening structure 3 applies pressure to the connecting portions of the two joints to improve contact and reduce contact resistance. In one embodiment, the installation structure for the superconducting cable 4 is further refined. The cable mounting portion 11 is provided with an installation groove 111. The installation groove 111 is a through groove into which the superconducting cable is inserted for installation. The superconducting connector 2 is disposed within the installation groove 111.

[0053] It should be noted that the structural arrangement of the installation groove 111 can not only play a role in installing and positioning the superconducting connector 2, but also facilitate the sinking installation of the superconducting cable 4, so as to further optimize the connection structure stability of the joint.

[0054] Specifically, in this embodiment, the depth of the mounting groove 111 is greater than the outer diameter of the superconducting cable 4. For example, the difference between the depth of the mounting groove 111 and the outer diameter of the superconducting cable 4 is greater than 1 mm. Of course, a difference less than 1 mm is also applicable to this embodiment. The depth can be determined by the thickness of the superconducting connector 2. By setting the depth of the mounting groove 111, a mounting position is reserved for the superconducting connector 2.

[0055] In one embodiment, in order to further optimize the installation stability of the superconducting cable 4 and the joint, in this implementation manner, the width direction of the installation groove 111 is arranged to be interference fit with the superconducting cable 4 .

[0056] The interference fit provides a damping connection between the superconducting cable 4 and the mounting groove 111 in the width direction. During installation and packaging, the clamping force formed by the damping can play a preliminary role in positioning the superconducting cable 4 so that the operator can perform subsequent packaging operations.

[0057] In one embodiment, the surface of the joint connection portion 12 is flush with the bottom of the mounting groove 111. This flush arrangement allows the superconducting connector 2 to be flush across the entire terminal assembly 1, and when the two connectors are crimped together, the crimping surface is smoother.

[0058] It should be noted that, since the specific number of superconducting tape layers depends on the design requirements, application scenarios and manufacturing processes of the superconducting cable, when designing a superconducting cable 4 with a larger number of superconducting tape layers, in some embodiments, one side of the installation groove 111 extends toward the joint connection portion 12 for the conductor connection end 22 to be embedded in the installation, so that the superconducting connector 2 as a whole can be embedded in the installation groove 111 for installation. Specific implementation method:

[0060] When using this connector, prepare to encapsulate the end of the superconducting cable 4, place the end of the superconducting cable 4 on the installation groove 111, and make the superconducting tape at the end of the superconducting cable 4 correspond one-to-one with the electrical connection surface of the cable connection end 21, and use low-temperature solder to encapsulate the cable in the installation groove 111. When the external conductor is another superconducting cable 4, the other superconducting cable 4 is also encapsulated, and the joint connection parts 12 of the two joints are fitted together, so that the conductor connection ends 22 on the two joints are fitted and crimped, and indium is used to fill the space between the conductor connection ends 22. Finally, bolts are used to provide pressure through the mounting holes and cold welding is used to improve the contact effect and reduce the contact resistance between the stacked superconducting cables 4. Under the connection structure of the joint, the current flowing from the external conductor into the superconducting connector 2 can be evenly distributed to the electrical connection surface of the stepped structure in the cable connection end 21. Because the various superconducting tapes at the cable end correspond one-to-one with the electrical connection surface of the cable connection end 21, the current can be evenly distributed to all superconducting tapes of the superconducting cable 4. This not only ensures that the current in the superconducting cable 4 is evenly distributed, but also further reduces the connection resistance between the superconducting cable 4 and other conductors, with the advantage of high connection efficiency.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A joint for a superconducting cable, characterized in that: include: The terminal assembly includes a cable mounting portion and a connector connecting portion that are integrally connected and located at both ends; a superconducting connector having multiple layers of stacked superconducting tapes welded to the terminal assembly, the superconducting connector passing through the cable installation portion and the joint connection portion, the superconducting connector comprising a cable connection end located at the cable installation portion and a conductor connection end located at the joint connection portion, wherein the conductor connection end is used to connect to an external conductor, the superconducting tapes in the cable connection end being arranged in a first stepped structure and capable of being paired and electrically connected to ends of the superconducting tapes of the superconducting cable arranged in a second stepped structure; A fastening structure is provided on the joint connecting portion and is used for rigidly connecting an external conductor.

2. The joint according to claim 1, wherein The number of first steps of the first stepped structure is greater than or equal to the number of second steps of the second stepped structure.

3. The connector according to claim 1, wherein The length of each first step in the first stepped structure is greater than or equal to the length of each second step in the second stepped structure.

4. The joint according to any one of claims 1 to 3, characterized in that The superconducting cable comprises a round-core superconducting cable. When wound to the end, each layer of superconducting tape from the inner layer to the outer layer differs from the end by at least one pitch, so as to form the second stepped structure at the end.

5. The connector according to claim 1, wherein The cable installation portion is provided with an installation groove, the superconducting connector is arranged at the bottom of the installation groove, and the superconducting cable can be arranged in the installation groove.

6. The joint according to claim 5, characterized in that A groove depth of the installation groove is greater than an outer diameter of the superconducting cable.

7. The connector according to claim 1, wherein The superconducting tapes in the conductor connection ends are arranged in a third stepped structure.

8. The joint according to claim 7, wherein The outer conductor includes another connector for a superconducting cable; The joint connection portion can be rigidly connected to a joint connection portion in another joint for a superconducting cable through the fastening structure, and the two third stepped structures corresponding to the two paired joint connection portions can be electrically connected to each other.

9. The joint according to claim 7, wherein The lengths of the third steps of the third stepped structure are the same, and the lengths of the plurality of third steps equally divide the length of the conductor connection end.

10. The joint according to claim 1, wherein The superconducting connector is connected to the terminal assembly by high-temperature soldering.

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