A superconducting cable laminar flow test device

Abstract

The present invention discloses a superconducting cable laminar flow testing device, comprising a probe positioning body sleeved on the outside of the cable, a fine-tuning assembly and a plurality of circumferentially arranged L-shaped probes installed on the probe positioning body, the L-shaped probe comprising a first probe rod for contacting the cable layer and a second probe rod connected to the first probe rod, the fine-tuning assembly comprising a fine-tuning nut and a threaded screw-in section arranged on the probe positioning body, the fine-tuning assembly acting on the second probe rod for adjusting the radial position of the second probe rod relative to the probe positioning body, and a first spring sleeved on the outside of the first probe rod for resetting the first probe rod. The present invention provides a superconducting cable laminar flow testing device, which can accurately measure the current actually flowing through each layer of the superconducting cable conductor layer without damaging the superconducting tape.

Description

Technical Field

[0001] The invention relates to the technical field of cable testing, in particular to a superconducting cable laminar flow testing device. Background Art

[0002] Superconducting cables are developed and demonstrated by various countries for their superior transmission characteristics of low loss, high efficiency and large capacity. They are highly applied in the future smart grid. As the demand for urban electricity consumption increases year by year, short-distance, high-voltage and large-capacity superconducting cables are particularly popular. However, the increase in the capacity of superconducting cables will lead to an excessively large outer diameter of the cable. Therefore, the conductor layer of the cable body is mostly designed with a layered structure. For the current carrying capacity of superconducting cables, a copper end is generally installed at the end of the cable to weld all the conductors together, and finally the power-on test is performed to obtain the overall critical current. If the actual current of each layer of the conductor needs to be known, the engineering can only weld a thin wire at the end of each superconducting tape to measure the layer current. After the test is completed, the wire is removed, which inevitably destroys the original appearance of the superconducting tape and may even cause damage. At present, there is no effective testing device that can reduce the difficulty of the operation and complete the test of the current of each layer of the conductor without damaging the superconducting tape.

[0003] For multi-layer superconducting cables, laminar current balance is an important design principle. Balancing the current of each layer of the conductor layer as much as possible can reduce the increase in power loss after the conductor layer design. To make the current of each layer equal, just ensure that the impedance of each layer is equal. By selecting process parameters such as the number of superconducting tapes, winding angle, and winding gap, the best can be achieved in theory. However, the actual current passing through each layer of the conductor can only be obtained through actual measurement. In engineering, it is generally necessary to install a copper end at the end of the cable to weld all the layers of superconducting tape together, so as to obtain the overall critical current and then estimate the current of each layer; if you want to know the actual current of each layer of conductor, it is very troublesome. It is necessary to weld a thin wire around the end of each superconducting tape or each layer of superconducting tape to measure the layer current, and then remove the wire after the test is completed. Since the inner layers are all inside the outermost layer, the welding operation can only be completed before the overall welding of the copper end, and good interlayer isolation is required to prevent the upper and lower layers from contacting each other, so the operation is particularly cumbersome; and welding additional wires will inevitably leave solder joints after removal, and the tiny protrusions of solder will inevitably destroy the original appearance of the superconducting tape; in addition, the instability of the welding temperature during the welding process, such as exceeding the allowable upper limit of the tape, may cause irreversible damage to the superconducting tape. Summary of the invention

[0004] The purpose of the present invention is to provide a superconducting cable laminar flow testing device, which can save cumbersome welding operations and the probe contact method does not damage the superconducting tape at all, and can easily realize the test of each layer current of the superconducting cable.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a superconducting cable laminar flow testing device, comprising a probe positioning body sleeved on the outside of the cable, the probe positioning body being equipped with a fine-tuning assembly and a plurality of circumferentially arranged L-shaped probes, the L-shaped probe comprising a first probe rod for contacting the cable layer and a second probe rod connected to the first probe rod, the fine-tuning assembly comprising a fine-tuning nut and a threaded screw-in section arranged on the probe positioning body, the fine-tuning assembly acting on the second probe rod for adjusting the radial position of the second probe rod relative to the probe positioning body, and a first spring being sleeved on the outside of the first probe rod for resetting the first probe rod.

[0006] Preferably, an insulating gasket is provided on the inner side of the probe positioning body for direct contact with the cable layer.

[0007] Preferably, a first countersunk hole matching the first probe rod and a longitudinal groove matching the second probe rod are radially opened on the probe positioning body, and the first spring is clamped in the first countersunk hole.

[0008] Preferably, the fine-tuning nut comprises an internal thread sleeve matching the threaded screw-in section and a conical sleeve matching the second probe rod, wherein the conical sleeve extends in a direction away from the probe positioning body and the cross-sectional radius gradually decreases.

[0009] Preferably, a second spring is sleeved on the outer side of the second probe rod, the longitudinal groove is configured as a stepped groove, the second spring is disposed in the wide groove of the stepped groove, and when the L-shaped probe is in the installed state, the second spring has a certain amount of compression deformation.

[0010] Preferably, two fine-tuning components and two rows of L-shaped probes which are arranged in parallel with each other and respectively matched with the two fine-tuning components are symmetrically mounted on the probe positioning body for testing different cable layers.

[0011] Preferably, the fine-tuning assembly is composed of two semi-annular oxygen-free copper shells, and a bolt connection ear is provided at the connection between the two oxygen-free copper shells for fixedly connecting the two oxygen-free copper shells and connecting an external test wire.

[0012] Preferably, the ends of the first probe rod and the second probe rod are both plated with a silver layer, and the contact surface of the conical sleeve with the second probe rod is plated with a silver layer.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention provides a probe positioning body which is sleeved on the outside of the cable and can be clamped on the cable for positioning. A fine-tuning assembly and a plurality of circumferentially arranged L-shaped probes are installed on the probe positioning body. The radial position of the second probe rod relative to the probe positioning body is adjusted by the fine-tuning assembly. The end surface of the L-shaped probe is silver-plated, and the current actually flowing in each layer of the superconducting cable conductor layer can be accurately measured without damaging the superconducting tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a superconducting cable laminar flow testing device of the present invention;

[0016] Figure 2 It is a cross-sectional side view of a superconducting cable laminar flow testing device of the present invention;

[0017] Figure 3 A cross-sectional perspective view of a superconducting cable laminar flow testing device according to the present invention;

[0018] Figure 4 It is a structural schematic diagram of an L-shaped probe in a superconducting cable laminar flow testing device of the present invention;

[0019] Figure 5 This is a structural diagram of the installation and use of a superconducting cable laminar flow testing device of the present invention.

[0020] In the figure: 1. laminar flow test device; 2. probe positioning body; 201. first countersunk hole; 202. longitudinal groove; 3. fine-tuning assembly; 301. fine-tuning nut; 3010. internal thread sleeve; 3011. conical sleeve; 302. threaded screw-in section; 303. bolt connection ear; 4. L-shaped probe; 401. first probe rod; 402. second probe rod; 403. first spring; 404. second spring; 5. insulating gasket; 6. superconducting cable; 7. superconducting tape; 8. current terminal. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] like Figure 1 and Figure 2As shown, the first embodiment provided by the present invention is a superconducting cable laminar flow testing device, comprising a probe positioning body 2 sleeved on the outside of the cable, the probe positioning body 2 is equipped with a fine-tuning assembly 3 and a plurality of circumferentially arranged L-shaped probes 4, and in this embodiment, two fine-tuning assemblies 3 and two rows of L-shaped probes 4 arranged in parallel with each other and respectively matched with the two fine-tuning assemblies 3 are symmetrically installed on the probe positioning body 2 for testing different cable layers. Among them, the L-shaped probe 4 includes a first probe rod 401 for contacting the cable layer and a second probe rod 402 connected to the first probe rod 401, the fine-tuning assembly 3 includes a fine-tuning nut 301 and a threaded screw-in section 302 arranged on the probe positioning body 2, the fine-tuning assembly 3 acts on the second probe rod 402, and is used to adjust the radial position of the second probe rod 402 relative to the probe positioning body 2, and the first probe rod 401 is sleeved with a first spring 403 on the outside to reset the first probe rod 401. The laminar flow test device 1 is provided with a probe positioning body 2 which is sleeved on the outside of the cable and can be clamped on the cable for positioning. A fine-tuning component 3 and a plurality of circumferentially arranged L-shaped probes 4 are installed on the probe positioning body 2. The radial position of the second probe rod 402 relative to the probe positioning body 2 is adjusted by the fine-tuning component 3. The end surface of the L-shaped probe 4 is silver-plated, so that the current actually flowing in each layer of the conductor layer of the superconducting cable 6 can be accurately measured without damaging the superconducting tape 7.

[0023] Preferably, the fine-tuning assembly 3 is composed of two semi-circular oxygen-free copper shells, and a bolt connection ear 303 is provided at the connection between the two oxygen-free copper shells, which is used to fix the two oxygen-free copper shells and connect the external test wire. And an insulating gasket 5 is provided on the inner side of the probe positioning body 2 for direct contact with the cable layer. The insulating gasket 5 is a Haversian structure, made of polytetrafluoroethylene material, and can be clamped on the cable to assist in positioning.

[0024] Specifically, Figure 2 As shown, the fine-tuning nut 301 includes an internal thread sleeve 3010 matching the threaded screw-in section 302 and a conical sleeve 3011 matching the second probe rod 402, wherein the conical sleeve 3011 extends in a direction away from the probe positioning body 2 and the cross-sectional radius gradually decreases, thereby the L-shaped probe 4 can be moved up and down by rotating the fine-tuning nut 301, wherein the second spring 404 is provided to ensure that the L-shaped probe 4 maintains a vertical position, and the first spring 403 provides elastic force for the upward movement of the L-shaped probe 4. The contact surface between the conical sleeve 3011 of the fine-tuning nut 301 and the second probe rod 402 of the L-shaped probe 4 is an inclined surface, which can convert the horizontal movement of the fine-tuning nut 301 screwed in and out into the vertical movement of the L-shaped probe 4, and the inner wall inclined surface of the fine-tuning nut 301 is in sliding contact with the arc surface of the end of the second probe rod 402 of the L-shaped probe 4.

[0025] like Figure 2 and Figure 3 As shown, the probe positioning body 2 is radially provided with a first countersunk hole 201 matching the first probe rod 401 and a longitudinal groove 202 matching the second probe rod 402, the first spring 403 is clamped in the first countersunk hole 201, and the first countersunk hole 201 simultaneously positions the L-shaped probe 4, and the specific number of holes can be determined according to the number of superconducting tapes 7 per layer of the cable. The outer side of the second probe rod 402 is sleeved with a second spring 404, the longitudinal groove 202 is set as a stepped groove, and the second spring 404 is set in the wide groove of the stepped groove. When the L-shaped probe 4 is in the installed state, the second spring 404 has a certain amount of compression deformation, which is used to ensure that the L-shaped probe 4 remains in a vertical position and does not shake slightly during the up and down movement.

[0026] like Figure 4 As shown, the L-shaped probe 4 includes a first probe rod 401 for contacting the cable layer and a second probe rod 402 connected to the first probe rod 401, the outer side of the first probe rod 401 is provided with a first spring 403 for self-resetting the first probe rod 401, and the outer side of the second probe rod 402 is provided with a second spring 404. When the L-shaped probe 4 is in the installed state, the second spring 404 has a certain compression deformation amount, which is used to ensure the stability of the L-shaped probe 4 during the longitudinal movement.

[0027] In addition, the surfaces of both ends of the first probe rod 401 and the second probe rod 402 of the L-shaped probe 4 are plated with a silver layer, and the contact surface of the conical sleeve 3011 with the second probe rod 402 is plated with a silver layer, which can achieve effective contact with the superconducting tape 7 without damaging the superconducting tape 7, and accurately measure the current actually flowing in each layer of the conductor layer of the superconducting cable 6.

[0028] like Figure 5 As shown, when the laminar flow test device 1 is used, the probe positioning body 2 needs to be installed on different superconducting tapes 7 of the superconducting cable 6, so that the two rows of L-shaped probes 4 arranged parallel to each other on the probe positioning body 2 can contact different layers of superconducting tapes 7, and at the same time realize the test of the flow capacity of two layers of superconducting tapes 7.

[0029] During actual testing, two sets of the laminar flow test device 1 can be respectively installed at the two ends of the superconducting cable 6 near the current terminal 8 for positioning and assembly. When installing the probe positioning body 2, slightly clamp the outer surface of the cable so as not to cause loosening and displacement. According to the number of superconducting tapes 7 in each layer, a corresponding number of L-shaped probes 4 are installed into the probe positioning body 2 to ensure that each probe is effectively pressed against each superconducting tape 7. Slightly tighten the fine adjustment nut 301 to make the metal end of the second probe rod 402 on the L-shaped probe 4 effectively contact the inner wall of the cone sleeve 3011, and then connect a thin wire to the bolt connection ear 303, and twist the wires of the corresponding conductor layers at the left and right ends of the cable to the test instrument terminal. When the superconducting cable 6 is powered on, the current value of each layer of the conductor layer can be read. When the test is completed, the device can be dismantled, and the superconducting tape 7 will remain in its original appearance without irreversible changes due to the power-on measurement, so that the current actually flowing in each layer of the conductor layer of the superconducting cable 6 can be accurately measured without damaging the superconducting tape 7.

[0030] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A superconducting cable laminar flow test device, It is characterized in that The invention comprises a probe positioning body (2) sleeved on the outside of the cable, a fine adjustment assembly (3) and a plurality of circumferentially arranged L-shaped probes (4) are installed on the probe positioning body (2), the L-shaped probe (4) comprises a first probe rod (401) for contacting the cable layer and a second probe rod (402) connected to the first probe rod (401), the fine adjustment assembly (3) comprises a fine adjustment nut (301) and a threaded screw-in section (302) arranged on the probe positioning body (2), the fine adjustment assembly (3) acts on the second probe rod (402) to adjust the second probe rod (402) The rod (402) is positioned radially relative to the probe positioning body (2); a first spring (403) is sleeved on the outer side of the first probe rod (401) for resetting the first probe rod (401); an insulating gasket (5) is provided on the inner side of the probe positioning body (2) for direct contact with the cable layer; a first countersunk hole (201) matching the first probe rod (401) and a longitudinal groove (202) matching the second probe rod (402) are radially opened on the probe positioning body (2); the first spring (403) is clamped in the first countersunk hole (201).

2. A superconducting cable laminar flow testing device according to claim 1, Features: The fine-tuning nut (301) comprises an internal thread sleeve (3010) matching the threaded screw-in section (302) and a conical sleeve (3011) matching the second probe rod (402); the conical sleeve (3011) extends in a direction away from the probe positioning body (2) and has a gradually decreasing cross-sectional radius.

3. A superconducting cable laminar flow testing device according to claim 2, Features: The outer side of the second probe rod (402) is sleeved with a second spring (404), the longitudinal groove (202) is configured as a stepped groove, and the second spring (404) is disposed in a wide groove of the stepped groove. When the L-shaped probe (4) is in an installed state, the second spring (404) has a certain amount of compression deformation.

4. A superconducting cable laminar flow testing device according to claim 2, Features: Two fine-tuning components (3) and two rows of L-shaped probes (4) arranged in parallel with each other and respectively matched with the two fine-tuning components (3) are symmetrically mounted on the probe positioning body (2) for testing different cable layers.

5. A superconducting cable laminar flow testing device according to claim 4, Features: The fine-tuning assembly (3) is composed of two semi-annular oxygen-free copper shells, and a bolt connection ear (303) is provided at the connection between the two oxygen-free copper shells for fixedly connecting the two oxygen-free copper shells and connecting an external test wire.

6. A superconducting cable laminar flow testing device according to claim 5, Features: The ends of the first probe rod (401) and the second probe rod (402) are both plated with a silver layer, and the contact surface of the cone sleeve (3011) with the second probe rod (402) is plated with a silver layer.

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