Hundred-meter superconducting cable 77k test fixture and method of using same

Abstract

This invention discloses a 77K testing fixture for 100-meter superconducting cables and its usage method, relating to the field of superconducting cable performance testing technology. It includes a liquid nitrogen tank and a fixing assembly. The fixing assembly consists of a cable reel component, a cable component, a lower support component for the cable reel, an upper support component for the cable reel, and current input / output lines. The liquid nitrogen tank serves as a 77K liquid nitrogen insulated container, the cable reel component acts as a cable winding skeleton, and the upper and lower support components support and position the cable end joints and leads. The current input / output lines establish a conductive circuit between the external power supply and the cable under test. The usage method includes six steps: cable winding, support assembly, lead fixing, liquid nitrogen filling, and wiring testing. This invention has a simple structure, low cost, and convenient operation. It can be adapted to 77K low-temperature testing of 100-meter superconducting cables of different lengths, filling the gap in the design and application of 77K testing fixtures for 100-meter superconducting cables and providing support for superconducting cable technology research and development.

Description

Technical Field

[0001] This invention relates to the field of superconducting cable performance testing technology, and in particular to a 77K testing fixture for a 100-meter superconducting cable and its usage method. Background Technology

[0002] Superconducting cables are a new type of cable that utilizes the property of superconducting materials to transmit electrical energy below their critical temperature. They offer significant advantages such as high transmission capacity, low line loss, and small footprint. High-temperature superconducting materials, such as rare-earth barium copper oxide (REBCO), have critical temperatures above 77K (the boiling point of liquid nitrogen). This makes it possible to use inexpensive and easy-to-operate liquid nitrogen as a cooling medium, greatly reducing the cooling cost of superconducting cables and significantly promoting their practical application.

[0003] With the continuous advancement of high-temperature superconducting tape fabrication technology, the length of a single tape can now reach hundreds of meters. The engineering application of superconducting cables is moving from short-sample verification to actual operating condition testing of hundred-meter-long cables. However, the 77K test of a hundred-meter-long superconducting cable differs fundamentally from that of a short-sample test, posing entirely new technical challenges to the testing equipment.

[0004] Firstly, regarding the construction and maintenance of the cryogenic environment, testing of 100-meter-long superconducting cables requires large-volume cryogenic containers. In existing technologies, small liquid nitrogen Dewars are usually sufficient for short-sample testing, but for 100-meter-long cables, the volume of the liquid nitrogen tank increases dramatically, and the consumption of liquid nitrogen is enormous, placing higher demands on the structural design of the tooling.

[0005] Secondly, regarding the ease of clamping and handling of superconducting cables, 100-meter-long superconducting cables are heavy, flexible, but have limited bending resistance, making clamping, positioning, and disassembly on testing fixtures far more difficult than with shorter samples. Most existing fixtures are designed for short rods or short strips, lacking effective guiding, supporting, and protective mechanisms for long cables, making it difficult to achieve fast and reliable clamping without damaging the cable.

[0006] Therefore, existing 77K testing fixtures for superconducting cables are mainly designed for short samples, and they cannot meet the testing requirements of 100-meter-long superconducting cables in terms of low-temperature environment construction and ease of operation. As high-temperature superconducting cables continue to develop towards longer lengths and higher voltage levels, there is an urgent need to develop a 77K testing fixture specifically for 100-meter-long superconducting cables to achieve efficient, accurate, and reliable comprehensive performance testing of long cables in the liquid nitrogen temperature range. Summary of the Invention

[0007] The main objective of this invention is to provide a 77K testing fixture for 100-meter superconducting cables and its usage method to solve the above-mentioned problems.

[0008] To achieve the above objectives, the present invention provides a 77K test fixture for a 100-meter superconducting cable, comprising a liquid nitrogen tank and a fixing assembly. The fixing assembly includes a cable reel component, a cable component, a lower support component for the cable reel, an upper support component for the cable reel, and current input / output lines. The liquid nitrogen tank is a 77K liquid nitrogen container for holding and insulating the entire set of fixed components; the cable reel component is a coiled and fixed skeleton for the cable component; the lower support component and the upper support component of the cable reel are respectively fixed to the lower and upper ends of the cable reel component for supporting and positioning the cable component; the current input / output line connects the external test power supply and the cable component to form a low-temperature conductivity test circuit.

[0009] Furthermore, the liquid nitrogen tank includes a main body, a support wheel assembly, a handle, and two liquid nitrogen inlets; the main body is a double-layer stainless steel sandwich structure, with the sandwich layer filled with a low thermal conductivity foaming agent and reinforced with a stainless steel square tube frame; the support wheel assembly is welded to the bottom of the main body, and the handle is welded to the side wall of the main body; the two liquid nitrogen inlets are located on the side wall of the main body and are equipped with dedicated valves for liquid nitrogen filling and liquid nitrogen recovery, respectively.

[0010] Furthermore, the cable reel component includes a main reel body; mounting holes are evenly distributed on the lower outer circular surface of the main reel body; a soft wrapping layer is attached to the middle outer circular surface of the main reel body; multiple upper-end fixing nuts are welded in a circumferential array on the upper circular surface of the main reel body; two lifting blocks are symmetrically welded on the upper circular surface of the main reel body, and each lifting block is screwed with a lifting ring.

[0011] Furthermore, the cable component includes a 100-meter superconducting cable; the 100-meter superconducting cable is wound on a soft sheath; both ends of the 100-meter superconducting cable are welded with connector terminals, and each connector terminal is crimped with an L-shaped current lead; an extension wire for the current lead is connected to the lower L-shaped current lead via an M8 screw kit.

[0012] Furthermore, the lower support component of the cable reel includes an L-shaped short support plate and a large C-shaped clamp; the L-shaped short support plate is assembled onto the mounting hole on the lower outer surface of the main reel body using an M5 screw kit, and the large C-shaped clamp is used to clamp and fix the connector terminal and L-shaped current lead located at the lower end onto the L-shaped short support plate.

[0013] Furthermore, the upper support component of the cable reel includes an L-shaped long support plate with a waist groove, an M24 screw kit, an arc plate, an arc plate connecting plate, an M6 screw kit, a small C-clamp, an M10 long screw, a first upper connector support plate, a second upper connector support plate, an extension cable fixing plate, and a large C-clamp. The upper end of the L-shaped long support plate is secured to the upper fixing nut with an M24 screw kit, and the lower end is connected to the arc plate connecting plate with an M6 screw kit; the arc plate is clamped to the arc plate connecting plate with a small C-clamp; the arc plate is used to support the upper part of the 100-meter superconducting cable; The threaded section of the M10 long screw mates with the screw hole on the vertical plate of the L-shaped long support plate, and the end contacts the cable reel component; the upper end of the first upper connector support plate is connected to the upper fixing nut via an M24 screw kit, and the lower end is connected to the second upper connector support plate via an M6 screw kit; the lower end of the second upper connector support plate is clamped to the connector terminal and L-shaped current lead located at the upper end via a large C-clamp; one end of the extension line fixing plate is connected to the upper fixing nut via an M24 screw kit, and the other end is clamped to the upper end of the current lead extension line via a large C-clamp.

[0014] Furthermore, the current input / output line includes a current input line and a current output line; the current input line and the current output line are respectively connected to the L-shaped current lead and the current lead extension line located at the upper end via an M12 screw kit.

[0015] This invention also provides a method for using a 77K testing fixture for 100-meter superconducting cables, comprising the following steps: S1. Coil the 100-meter superconducting cable around the outside of the soft wrapping layer of the cable reel component, and wrap the outer layer of the 100-meter superconducting cable with plastic wrap to constrain it. S2. Install the lower end support component of the cable, and apply polyimide tape to the upper surface of the lower end support component for insulation treatment; S3. Install the upper support component of the cable and apply polyimide tape to the upper surface of the upper support component for insulation treatment; S4. Prepare the connector terminals at the upper and lower ends of the cable component and install the L-shaped current leads, fixing them to the lower support component and the upper support component of the cable respectively. S5. Use a crane to lift the entire test fixture into the liquid nitrogen tank, and fill it with 77K liquid nitrogen through one of the liquid nitrogen ports to completely immerse the cable reel components. S6. Connect the current input / output lines to both ends of the cable component, and connect the test signal lines, etc. After completion, the superconducting cable 77K test can be performed.

[0016] The present invention has the following beneficial effects: 1. This invention has a simple structure, low cost, and can achieve efficient, accurate and reliable comprehensive performance testing of 100-meter-long superconducting cables in the liquid nitrogen temperature range, filling the gap in the design and application of testing fixtures for 77K testing of 100-meter-long superconducting cables.

[0017] 2. This invention is highly versatile and easy to operate. Most of the parts adopt a structure of waist-groove holes and circumferentially distributed holes, and the distance and position are adjustable, making it suitable for testing requirements of superconducting cables of different lengths (hundred meters). Attached Figure Description

[0018] Figure 1 This is a perspective view of the 77K test fixture for the 100-meter superconducting cable of the present invention; Figure 2 This is a schematic diagram of the main frame structure of the liquid nitrogen tank for the 77K test fixture for a 100-meter superconducting cable of the present invention; Figure 3 This is a schematic diagram of the main frame structure of the cable reel component of the 77K test fixture for a 100-meter superconducting cable of the present invention; Figure 4 This is a schematic diagram of the main frame structure of the cable component of the 77K test fixture for a 100-meter superconducting cable of the present invention; Figure 5 This is a schematic diagram of the main frame structure of the lower support component of the cable reel of the 77K test fixture for a 100-meter superconducting cable of the present invention; Figure 6 This is a schematic diagram of the main frame structure of the upper support component of the cable reel of the 77K test fixture for the 100-meter superconducting cable of the present invention; Figure 7 This is a schematic diagram of the main frame structure of the 77K test fixture for 100-meter superconducting cable of the present invention for current input / output; Figure 8 This is a schematic diagram of step one of the usage methods of the 77K test fixture for a 100-meter superconducting cable according to the present invention; Figure 9 This is a schematic diagram of step two in the usage method of the 77K test fixture for a 100-meter superconducting cable of the present invention; Figure 10 This is a schematic diagram of step three in the usage method of the 77K test fixture for a 100-meter superconducting cable according to the present invention; Figure 11 This is a schematic diagram of step four in the usage method of the 77K test fixture for a 100-meter superconducting cable of the present invention; Figure 12 This is a schematic diagram of step six in the usage method of the 77K test fixture for a 100-meter superconducting cable of the present invention; Among them, 1-liquid nitrogen tank, 101-main tank body, 102-support wheel assembly, 103-handle, 104-liquid nitrogen inlet; 2-Cable reel components, 201-Main reel body, 202-Soft wrapping layer, 203-Upper fixing nut, 204-Lifting ring, 205-Lifting block; 3-Cable components, 301-100-meter superconducting cable, 302-Connector terminal, 303-L-shaped current lead, 304-Current lead extension wire, 305-M8 screw kit; 4- Lower support component of cable reel, 401- L-shaped short support plate, 402- M5 screw kit, 403- Large C-shaped clip; 5- Upper support component of cable reel, 501- L-shaped long support plate, 502- M24 screw kit, 503- Arc plate, 504- Arc plate connecting plate, 505- M6 screw kit, 506- Small C-shaped clip, 507- M10 long screw, 508- First upper connector support plate, 509- Second upper connector support plate, 510- Extension line fixing plate; 6-Current input / output line, 601-Current input line, 602-Current output line, 603-M12 screw kit. Detailed Implementation

[0019] To achieve the above objectives and effects, the technical means and structure adopted by the present invention will be described in detail with reference to the accompanying drawings, focusing on the features and functions of the preferred embodiments of the present invention.

[0020] Example 1

[0021] like Figure 1 As shown, this invention provides a testing fixture for a 100-meter superconducting cable 77K, including a liquid nitrogen tank 1, a cable reel component 2, a cable component 3, a lower support component 4 for the cable reel, an upper support component 5 for the cable reel, and a current input / output line 6. The liquid nitrogen tank 1 is the testing container; the cable reel component 2 serves as the mounting frame for the cable component 3 under test; the lower support component 4 provides support for the connector terminal 302 at the lower end of the 100-meter superconducting cable 301 and the transition section of the superconducting cable; the upper support component 5 provides support for the connector terminal 302 at the upper end of the 100-meter superconducting cable 301 and the transition section of the superconducting cable; and the current input / output line 6 is used to connect to an external power source.

[0022] like Figure 2 As shown, the liquid nitrogen tank 1 includes a main body 101, a support wheel assembly 102, a handle 103, and a liquid nitrogen inlet 104. The main body 101 has a sandwich structure, with multiple stainless steel square tubes welded and interconnected to form a load-bearing frame inside, and the outer surface is made of stainless steel thin plates welded together, with a low thermal conductivity foaming agent filling the middle. The support wheel assembly 102 consists of multiple nylon universal wheels and directional wheels, distributed around the bottom of the main body and at the center, and is connected to the main body by welding. The handle 103 is welded to the main body 101. The liquid nitrogen inlet 104 consists of two liquid nitrogen-specific valves, which are welded to the main body and communicate with the inner cavity of the main body, allowing connection to external pipelines for input or recovery of liquid nitrogen.

[0023] like Figure 3As shown, the cable reel component 2 includes a main reel body 201, a soft sheathing layer 202, an upper fixing nut 203, a lifting ring 204, and a lifting block 205. The lower outer circular surface of the main reel body 201 has circumferentially distributed holes, the middle outer circular surface is attached with the soft sheathing layer 202, the upper fixing nut 203 is welded circumferentially at equal intervals on the upper circular surface, and the lifting block 205 is welded at symmetrical positions in the middle of the upper circular surface. The lifting ring 204 is threadedly connected to the lifting block 205.

[0024] like Figure 4 As shown, cable component 3 includes a 100-meter superconducting cable 301, a connector terminal 302, an L-shaped current lead 303, a current lead extension line 304, and an M8 screw kit 305. The upper and lower ends of the 100-meter superconducting cable 301 are connected to the connector terminal 302 by soldering. The connector terminal 302 is crimped to the contact surface of the L-shaped current lead 303. The L-shaped current lead 303 and the current lead extension line 304 are crimped to each other by the M8 screw kit 305.

[0025] like Figure 5 As shown, the lower support component 4 of the cable reel includes an L-shaped short support plate 401, an M5 screw kit 402, and a large C-shaped clamp 403. The L-shaped short support plate 401 is connected to the circumferentially distributed holes on the lower outer surface of the main reel body 201 through the M5 screw kit 402. The large C-shaped clamp 403 can clamp and fix the connector terminal 302 and the L-shaped current lead 303 to the L-shaped short support plate 401.

[0026] like Figure 6As shown, the upper support component 5 of the cable reel includes an L-shaped long support plate 501 with a groove, an M24 screw kit 502, an arc plate 503, an arc plate connecting plate 504, an M6 screw kit 505, a small C-clamp 506, an M10 long screw 507, a first upper connector support plate 508, a second upper connector support plate 509, an extension cable fixing plate 510, and a large C-clamp 403. The upper end of the L-shaped long support plate 501 is secured to the upper fixing nut 203 by the M24 screw kit 502, and the lower end is connected to the arc plate connecting plate 504 by the M6 ​​screw kit 505. The arc plate 503 is clamped to the arc plate connecting plate 504 by the small C-clamp 506. The arc plate 503 is used to support the 100-meter superconducting cable 301. The upper part; the threaded section of the M10 long screw 507 mates with the screw hole on the vertical plate of the L-shaped long support plate 501, and the end contacts the cable reel component 2; the upper end of the first upper connector support plate 508 is connected to the upper fixing nut 203 through the M24 screw kit 502, and the lower end is connected to the second upper connector support plate 509 through the M6 ​​screw kit 505; the lower end of the second upper connector support plate 509 is clamped to the connector terminal 302 and the L-shaped current lead 303 located at the upper end through the large C-clamp 403; one end of the extension line fixing plate 510 is connected to the upper fixing nut 203 through the M24 screw kit 502, and the other end is clamped to the upper end of the current lead extension line 304 through the large C-clamp 403.

[0027] like Figure 7 As shown, the current input / output line 6 includes a current input line 601, a current output line 602, and an M12 screw kit 603. The current input line 601 and the current output line 602 are respectively connected to the L-shaped current lead 303 and the current lead extension line 304 via the M12 screw kit 603 for conduction.

[0028] Example 2

[0029] This invention also provides a method for using a 77K testing fixture for 100-meter superconducting cables, comprising the following steps: S1. Coil the 100-meter superconducting cable 301 around the soft wrapping layer 202 of the cable reel component 2, and wrap the 100-meter superconducting cable 301 with plastic wrap to constrain it. S2. Install the lower cable support component 4, and apply polyimide tape to the upper surface of the lower cable support component for insulation. S3. Install the upper support component 5 of the cable and apply polyimide tape to the upper surface of the upper support component for insulation treatment; S4. Prepare the connector terminals 302 at the upper and lower ends of the cable component 3 and install the L-shaped current lead 303, which are respectively fixed to the lower end support component 4 and the upper end support component 5 of the cable. S5. Use a crane to lift the entire test fixture into the liquid nitrogen tank 1, and add 77K liquid nitrogen through one of the liquid nitrogen ports 104 to completely immerse the cable reel component 2. S6. Connect the current input / output line 6 to both ends of the cable component 3, and connect the test signal line, etc. After completion, the superconducting cable 77K test can be performed.

[0030] The above description is only a preferred embodiment of the present invention and not all embodiments. Anyone should know that structural changes made under the guidance of the present invention, and any technical solutions that are the same as or similar to the present invention, are within the protection scope of the present invention.

Claims

1. A testing fixture for a 100-meter superconducting cable (77K), characterized in that, It includes a liquid nitrogen tank (1) and a fixing assembly, the fixing assembly including a cable reel component (2), a cable component (3), a lower cable reel support component (4), an upper cable reel support component (5), and a current input / output line (6). The liquid nitrogen tank (1) is a 77K liquid nitrogen container for holding and insulating, used to house the entire set of fixed components; the cable reel component (2) is the coiled and fixed skeleton of the cable component (3); the lower end support component (4) and the upper end support component (5) of the cable reel are respectively fixed to the lower end and the upper end of the cable reel component (2) for supporting and positioning the cable component (3); the current input / output line (6) connects the external test power supply and the cable component (3) to form a low-temperature conductivity test circuit.

2. The 77K test fixture for a 100-meter superconducting cable as described in claim 1, characterized in that, The liquid nitrogen tank (1) includes a main body (101), a support wheel assembly (102), a handle (103), and two liquid nitrogen ports (104). The main body (101) is a double-layer stainless steel sandwich structure, with the sandwich filled with a low thermal conductivity foaming agent and reinforced with a stainless steel square tube frame. The support wheel assembly (102) is welded to the bottom of the main body (101), and the handle (103) is welded to the side wall of the main body (101). The two liquid nitrogen ports (104) are located on the side wall of the main body (101) and are equipped with dedicated valves for liquid nitrogen filling and liquid nitrogen recovery, respectively.

3. The 77K test fixture for a 100-meter superconducting cable as described in claim 2, characterized in that, The cable reel component (2) includes a main reel body (201); mounting holes are evenly provided on the lower outer circular surface of the main reel body (201); a soft wrapping layer (202) is attached to the middle outer circular surface of the main reel body (201); multiple upper fixing nuts (203) are welded in a circumferential array on the upper circular surface of the main reel body (201); two lifting blocks (205) are symmetrically welded on the upper circular surface of the main reel body (201), and each lifting block (205) is screwed with a lifting ring (204).

4. The 77K test fixture for a 100-meter superconducting cable as described in claim 3, characterized in that, The cable component (3) includes a 100-meter superconducting cable (301); the 100-meter superconducting cable (301) is wound on a soft sheath (202); both ends of the 100-meter superconducting cable (301) are welded with connector terminals (302), and each connector terminal (302) is crimped with an L-shaped current lead (303); an extension wire (304) is connected to the L-shaped current lead (303) at the lower end by an M8 screw kit (305).

5. The 77K test fixture for a 100-meter superconducting cable as described in claim 4, characterized in that, The lower support component (4) of the cable reel includes an L-shaped short support plate (401) and a large C-shaped clamp (403); the L-shaped short support plate (401) is assembled onto the mounting hole on the lower outer surface of the main reel body (201) by means of an M5 screw kit (402), and the large C-shaped clamp (403) is used to clamp and fix the connector terminal (302) and the L-shaped current lead (303) located at the lower end onto the L-shaped short support plate (401).

6. The 77K test fixture for a 100-meter superconducting cable as described in claim 5, characterized in that, The upper support component (5) of the cable reel includes an L-shaped long support plate (501) with a waist groove, an M24 screw kit (502), an arc plate (503), an arc plate connecting plate (504), an M6 screw kit (505), a small C-clamp (506), an M10 long screw (507), a first upper connector support plate (508), a second upper connector support plate (509), an extension line fixing plate (510), and a large C-clamp (403). The upper end of the L-shaped long support plate (501) is locked to the upper fixing nut (203) by an M24 screw kit (502), and the lower end is connected to the arc plate connecting plate (504) by an M6 screw kit (505); the arc plate (503) is clamped to the arc plate connecting plate (504) by a small C-shaped clamp (506); the arc plate (503) is used to support the upper part of the 100-meter superconducting cable (301); The threaded section of the M10 long screw (507) engages with the screw hole on the vertical plate of the L-shaped long support plate (501), and the end engages with the cable reel component (2); the upper end of the first upper connector support plate (508) is connected to the upper fixing nut (203) through the M24 screw kit (502), and the lower end is connected to the second upper connector support plate (509) through the M6 ​​screw kit (505); the lower end of the second upper connector support plate (509) is clamped to the connector terminal (302) and the L-shaped current lead (303) located at the upper end through the large C-clamp (403); one end of the extension line fixing plate (510) is connected to the upper fixing nut (203) through the M24 screw kit (502), and the other end is clamped to the upper end of the current lead extension line (304) through the large C-clamp (403).

7. The 77K test fixture for a 100-meter superconducting cable as described in claim 1, characterized in that, The current input / output line (6) includes a current input line (601) and a current output line (602); the current input line (601) and the current output line (602) are respectively connected to the L-shaped current lead (303) and the current lead extension line (304) located at the upper end by an M12 screw kit (603).

8. A method for using a 77K testing fixture for a 100-meter superconducting cable, characterized in that, Using the 77K test fixture for a 100-meter superconducting cable as described in any one of claims 4-7, the following steps are included: S1. The 100-meter superconducting cable (301) is coiled around the outside of the soft wrapping layer (202) of the cable reel component (2), and a plastic wrap is wrapped around the outer layer of the 100-meter superconducting cable (301) to restrain it. S2. Install the lower end support component (4) of the cable and apply polyimide tape to the upper surface of the lower end support component for insulation treatment; S3. Install the upper support component (5) of the cable and apply polyimide tape to the upper surface of the upper support component for insulation treatment; S4. Prepare the connector terminals (302) at the upper and lower ends of the cable component (3) and install the L-shaped current lead (303), which are respectively fixed on the lower end support component (4) and the upper end support component (5) of the cable. S5. Using a crane, the entire test fixture is lifted into the liquid nitrogen tank (1), and 77K liquid nitrogen is added through one of the liquid nitrogen ports (104) to completely immerse the cable reel component (2). S6. Connect the current input / output line (6) to both ends of the cable component (3) respectively, and connect the test signal line, etc. After completion, the superconducting cable 77K test can be performed.

Images