Superconducting strip testing device and system

Abstract

The utility model relates to a superconducting tape testing device and system, and the device comprises a fixing unit which is used for fixing a to-be-tested tape, and the to-be-tested tape is provided with at least one connector; the current input unit comprises a power supply, the power supply is electrically connected with the to-be-tested strip through two current leads, and two first connecting points of the current leads and the to-be-tested strip are located on the two sides of the connector; the current detection unit comprises a shunt resistor connected in series with one of the current leads and a first measuring device connected with the shunt resistor; the voltage detection unit comprises a second measuring device, the second measuring device is connected with the to-be-detected strip through two voltage leads, and two second connecting points of the voltage leads and the to-be-detected strip are located on the inner sides of the two first connecting points and located on the two sides of the connector; and the cold source is in contact with the to-be-tested strip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of superconducting technology, in particular to a superconducting tape testing device and system. BACKGROUND

[0002] Superconducting magnets have great application prospects in the fields of electric power, new energy, rail transit, large scientific devices, etc. However, it cannot be ignored that there is a risk of quench in superconducting magnets, and since the quench of superconducting magnets is difficult to detect, if effective measures are not taken in advance to protect and process the superconducting magnets, system damage is likely to occur.

[0003] The core component of a superconducting magnet is a superconducting coil, which is often wound and welded by multiple superconducting tapes. The welded joints in the superconducting tapes and some other defects in the superconducting tapes may become defect points of low critical current in the superconducting coil and induce quench. In order to avoid system damage caused by quench, it is necessary to detect the quality of the superconducting coil before assembly, find the defect points of low critical current in advance and take corresponding measures to avoid inducing quench during the operation of the superconducting magnet.

[0004] Therefore, how to accurately find the defect points in the superconducting tape becomes a technical problem to be solved. CONTENT OF THE INVENTION

[0005] The present application provides a superconducting tape testing device and system to solve the technical problem of how to accurately find the defect points in the superconducting tape.

[0006] According to a first aspect, the embodiments of the present application provide a superconducting tape testing device, comprising: a fixing unit for fixing a to-be-tested tape, the to-be-tested tape having at least one joint; a current input unit comprising a power supply, the power supply being electrically connected to the to-be-tested tape through two current leads, wherein the current leads and two first connection points of the to-be-tested tape are located on both sides of the joint; a current detection unit comprising a shunt resistor connected in series to one of the current leads and a first measuring device connected to the shunt resistor; a voltage detection unit comprising a second measuring device, the second measuring device being connected to the to-be-tested tape through two voltage leads, the voltage leads and two second connection points of the to-be-tested tape being located inside the two first connection points and on both sides of the joint; and a cold source in contact with the to-be-tested tape.

[0007] In an embodiment, the current leads are connected to the to-be-tested tape through a crimping structure.

[0008] In an embodiment, the voltage leads are welded to the to-be-tested tape.

[0009] In an embodiment, the cold source comprises a liquid nitrogen container, liquid nitrogen is contained in the liquid nitrogen container, and the fixing unit is arranged in the liquid nitrogen container, and the superconducting tape is immersed in the liquid nitrogen.

[0010] In an embodiment, the fixing unit comprises a tape bearing part and a supporting part, one end of the supporting part is fixedly connected with the bearing part, and the other end of the supporting part is connected with a side wall or a cover of the liquid nitrogen container.

[0011] In an embodiment, the supporting part comprises a feed-through electrode, the feed-through electrode penetrates through the liquid nitrogen container and is electrically connected with the tape bearing part, the tape bearing part is electrically connected with the to-be-tested tape, and the feed-through electrode is electrically connected with the current lead.

[0012] In an embodiment, the cold source further comprises a refrigerator and a cold conducting structure, one end of the cold conducting structure is connected with a cold head of the refrigerator, and the other end of the cold conducting structure is in contact with a crimping area of the current lead on the to-be-tested tape.

[0013] In an embodiment, the crimping structure comprises a crimping sheet and a crimping solder, the crimping solder is arranged between the to-be-tested tape and the current lead, the crimping sheet crimps the to-be-tested tape, the crimping solder and the current lead, the crimping structure further comprises a heat capacity sheet, the heat capacity sheet is arranged between the crimping solder and the current lead or between the crimping solder and the to-be-tested tape, and the other end of the cold conducting structure is in contact with the heat capacity sheet.

[0014] According to a second aspect, the embodiments of the present application provide a superconducting tape measuring system, comprising a host computer and the superconducting tape testing device according to any one of the first aspect.

[0015] In an embodiment, the host computer further comprises a measurement operation end, which is used for setting a measurement parameter and displaying a measurement result.

[0016] The present application has at least the following beneficial effects:

[0017] In the present application, the power supply passes a gradually increasing current to the to-be-tested tape through the current lead, the first measuring device can adopt an ammeter to measure the current passed in the to-be-tested tape by collecting the voltage on the shunt resistor, and the second measuring device can adopt a nanovoltmeter to measure the joint resistance of the superconducting tape by detecting the voltage on the to-be-tested tape and the current passed in. The voltage lead is connected on both sides of the welded joint, and the current lead is connected outside the connection point of the voltage lead and the to-be-tested tape, so as to avoid the influence of the resistance of the connection point of the current lead and the to-be-tested tape on the voltage measurement, and the joint resistance of the joint can be more accurately measured. In order to more accurately find the defect point in the superconducting tape.

[0018] Further, the liquid nitrogen container can adopt a closed liquid nitrogen box, the liquid nitrogen box is provided with a liquid inlet port and a liquid outlet port, the liquid inlet port is communicated with the liquid nitrogen source, and the liquid outlet port is communicated with the liquid nitrogen recovery device, so that the liquid nitrogen can circulate in the liquid nitrogen container, and the to-be-tested strip is ensured to be in the liquid nitrogen. And the flowing liquid nitrogen can accelerate the conduction of the local Joule heat generated between the current lead and the to-be-tested strip due to the pressure connection, and reduce the risk of local temperature rise.

[0019] Further, the pressure connection structure further comprises a heat capacity sheet arranged between the pressure connection solder and the current lead or between the pressure connection solder and the to-be-tested strip, and the other end of the heat dissipation structure is in contact with the heat capacity sheet. The heat capacity sheet adopts a metal sheet with high heat conduction capacity, for example, a silver sheet with large volume / area, which has large heat capacity and large heat dissipation area, so there is no obvious temperature rise, thereby inhibiting the diffusion of the Joule heat generated by the to-be-tested strip and inhibiting the diffusion of the temperature rise of the to-be-tested strip. So that the test can be effectively carried out.

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are described in detail as follows. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0022] Figure 1 A modular schematic diagram of a superconducting strip testing device provided by the embodiments of the present application.

[0023] Figure 2 A structural schematic diagram of a superconducting strip testing device provided by the embodiments of the present application.

[0024] Figure 3 A structural schematic diagram of a liquid nitrogen box provided by the embodiments of the present application.

[0025] Figure 4 A schematic diagram of a pressure connection structure provided by the embodiments of the present application.

[0026] Figure 5 A structural schematic diagram of a superconducting strip testing system provided by the embodiments of the present application.

[0027] The schematic diagram is as follows:

[0028] 10, fixing unit; 11, to-be-tested tape; 111, joint; 12, tape bearing part; 13, support part; 20, current input unit; 21, power supply; 22, current lead; 221, first current lead; 222, second current lead; 23, crimp structure; 231, crimping sheet; 232, crimping solder; 233, bolt; 30, current detection unit; 31, shunt resistor; 32, first measuring device; 40, voltage detection unit; 41, second measuring device; 42, voltage lead; 421, first voltage lead; 422, second voltage lead; 50, cold source; 51, liquid nitrogen box; 512, liquid inlet port; 513, liquid outlet port; 52, liquid nitrogen; 53, liquid nitrogen source; 54, liquid nitrogen recovery device; 60, upper computer. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0030] As shown in Figures 1-4 The superconducting tape testing device provided by the embodiments of the present application includes a fixing unit 10 (see the fixing unit shown in Figure 3 ), which is used to fix a to-be-tested tape 11, and the to-be-tested tape 11 has at least one joint 111. The to-be-tested tape 11 can be a superconducting coil or a superconducting tape sample with a welded joint, and the present application does not limit this. In the embodiments of the present application, a superconducting tape sample with a welded joint is taken as an example for description. The superconducting tape testing device further includes a current input unit 20, which includes a power supply 21, and the power supply 21 is electrically connected to the to-be-tested tape 11 through two current leads 22, wherein the two current leads 22 (such as Figure 1 and Figure 2The first current lead 221 and the second current lead 222 shown in FIG. 1 are respectively led out from the positive pole and the negative pole of the power supply 21, and are respectively connected with the to-be-tested tape 11, and the two connection points (referred to as "first connection points") of the first current lead 221 and the second current lead 222 with the to-be-tested tape are located on the two sides of the joint 111; the current detection unit 30 comprises a shunt resistor 31 connected in series with the first current lead 221 and a first measuring device 32 connected with the shunt resistor 31; the voltage detection unit 40 comprises a second measuring device 41 connected with the to-be-tested tape 11 through two voltage leads 42 (such as Figure 1 and Figure 2 the first voltage lead 421 and the second voltage lead 422 in FIG. 1 are respectively connected to two measuring ports of the second measuring device 41, and the two connection points (referred to as "second connection points") of the first voltage lead 421 and the second voltage lead 422 with the to-be-tested tape 11 are located inside the two first connection points and on the two sides of the joint 111. The cold source 50 is in contact with the to-be-tested tape 11 to provide cold to the to-be-tested tape 11 to avoid large temperature change of the to-be-tested tape.

[0031] In the embodiment, the power supply passes the to-be-tested tape 11 with gradually increased current through the current lead 22, the first measuring device 32 can adopt an ammeter to measure the current passed in the to-be-tested tape 11 by collecting the voltage on the shunt resistor 31; the second measuring device 41 can adopt a nanovoltmeter to measure the joint resistance of the superconducting tape by detecting the voltage on the to-be-tested tape 11 and the obtained passed current. Wherein, the voltage lead 42 is connected on the two sides of the welded joint 111, and the current lead 22 is connected outside the connection points of the voltage lead 42 and the to-be-tested tape 11 to ensure that the resistance of the connection points of the current lead 22 and the to-be-tested tape 11 is not affected when the voltage is measured, and the joint resistance of the joint 111 can be more accurately measured.

[0032] The first measuring device 32 and the second measuring device 41 can also adopt an integrated current / voltage data acquisition chip.

[0033] In an embodiment, in order to further increase the accuracy of the voltage measurement unit, in the embodiment, the voltage lead 42 can be welded on the two sides of the joint 111 of the to-be-tested tape 11.

[0034] In the embodiment, the solder used for welding the voltage lead 42 can adopt low-temperature solder with a temperature lower than 250℃ for welding.

[0035] In an embodiment, in order to facilitate the to-be-tested tape 11 to be more quickly mounted and dismounted, the current lead 22 can be electrically connected with the to-be-tested tape 11 through a crimping structure 23. The to-be-tested tape 11 can be conveniently and quickly mounted through the crimping structure 23.

[0036] The crimping structure 23 can include a crimping sheet 231 and a crimping solder 232 arranged between the to-be-tested strip 11 and the current lead 22, and the crimping sheet 231 crimps the to-be-tested strip 11, the crimping solder 232 and the current lead 22. The crimping solder 232 can be a soft crimping solder such as an indium sheet or a silver sheet. In this embodiment, the crimping sheet 231 can be an elastic crimping sheet, which includes a fixed end and a free end, and crimps the to-be-tested strip 11, the crimping solder 232 and the current lead 22 together by elastic force to realize electrical connection. In another embodiment, the crimping sheet 231 can also be a rigid crimping sheet, which is fastened to the to-be-tested strip 11, the crimping solder 232 and the current lead 22 by a bolt 233. Figure 4

[0037] In an embodiment, the cold source can be a liquid nitrogen container containing liquid nitrogen, and the fixing unit 10 is arranged in the liquid nitrogen container, and the to-be-tested strip 11 is immersed in the liquid nitrogen.

[0038] In an embodiment, as shown in Figure 3 The liquid nitrogen container can be a closed liquid nitrogen box 51, which is provided with an inlet port 512 and an outlet port 513, the inlet port 512 is communicated with a liquid nitrogen source 53, and the outlet port 513 is communicated with a liquid nitrogen recovery device 54, so that the liquid nitrogen 52 can circulate in the liquid nitrogen container, and the to-be-tested strip 11 is always immersed in the liquid nitrogen 52. And the flowing liquid nitrogen 52 can accelerate the conduction of the local Joule heat generated between the current lead 22 and the to-be-tested strip 11 due to crimping, and reduce the risk of local temperature rise.

[0039] In an embodiment, the fixing unit 10 includes a strip bearing part 12 and a support part 13, one end of the support part 13 is fixedly connected with the strip bearing part 12, and the other end of the support part 13 is connected to the side wall or cover of the liquid nitrogen container. In this embodiment, the support part 13 and the strip bearing part 12 can be part of the current lead 22, the support part 13 includes a feed-through electrode which penetrates through the liquid nitrogen container and is electrically connected with the strip bearing part 13, the strip bearing part 12 is electrically connected with the to-be-tested strip 11, and the feed-through electrode is electrically connected with the current lead 22.

[0040] As shown in Figure 4 The crimping structure 23 can be a crimping structure with a rigid crimping sheet, a screw hole is formed in the strip bearing part 12, and the crimping sheet 231 is fastened to the strip bearing part 12 by a bolt 233, so that the crimping sheet 231 crimps the to-be-tested strip 11, the crimping solder 232 and the current lead 22 together. ​

[0041] As the current increases, the heat accumulation at the crimping point of the current lead 22 will increase significantly. Therefore, in order to further accelerate the heat conduction at the crimping point of the current lead 22, in this embodiment, the cold source also includes a refrigerator and a cooling structure. One end of the cooling structure is connected to the cold head of the refrigerator, and the other end is in contact with the crimping area of ​​the current lead 22 on the strip to be tested 11.

[0042] To further enhance the heat dissipation efficiency of the press-fit joint, in this embodiment, the press-fit structure 23 also includes a heat-capacitance sheet, disposed between the press-fit solder 232 and the current lead 22, or between the press-fit solder 232 and the strip 11 under test. The other end of the cooling structure is in contact with the heat-capacitance sheet. The heat-capacitance sheet is made of a metal sheet with high thermal conductivity, for example, a silver sheet with a large volume / area, which has a large heat capacity and a large heat dissipation area. Therefore, there will be no significant temperature rise, thereby suppressing the diffusion of Joule heat generated by the strip 11 under test and suppressing the diffusion of temperature rise in the strip 11 under test. This allows the test to be performed effectively.

[0043] This application also provides a superconducting tape measurement system, such as... Figure 5 As shown, it includes a host computer 60 and any of the superconducting tape testing devices described in the above embodiments. The host computer 60 is connected to the first measuring device 32 and the second measuring device 41 via power communication.

[0044] In one embodiment, the host computer 60 further includes a measurement operation terminal for setting measurement parameters and displaying measurement results.

[0045] During testing, after clicking the "Start" button on the measurement operation terminal, a DataFrame (columns = ['t imestamp', 'TDK_U', 'TDK_I', ...) will be created in the host computer 60.

[0046] The `aVoltage` parameter is used to store timestamps, power supply voltage, output current, and test object voltage data. The `create_chart` function in the host computer 60 generates the initial UI and Ut graphs and sets their styles. The `update_TDK` thread in the host computer 60 reads the power supply voltage from the power feedback and the power supply current data collected by the first measuring device 32. The `update_aVoltage` thread in the host computer 60 reads the voltage data collected by the second measuring device 41. The numerical display bar is associated with the corresponding data variable and displayed in real time. The `update_plot_loop` thread in the host computer 60 extracts data from the DataFrame and displays it in real time on the UI and Ut graphs of the front-end interface.

[0047] After starting, the test parameters are set by measuring the operating end, including sample length, target current, quench criterion, current rise rate and current fall rate. Among them, the sample length is the length of the measured strip 11 within the range of the second connection point of the voltage lead 42. The target current is the stable current value after the power supply changes from the current value according to the set rise / fall rate. The quench criterion is the product of this value and the sample length, and the quench voltage value is obtained as the quench threshold for system judgment. The current rise rate is the rate at which the current source will rise if the target current is higher than the current value. The current fall rate is the rate at which the current source will fall if the target current is lower than the current value.

[0048] After completing the parameter setting, the set_values function is triggered by clicking the "set" button on the measurement operating end. The function sets the "target current", "current rise rate" and "current fall rate" captured by the front-end control into the device through the corresponding SCP I command. At the same time, the sample length and the quench criterion are put into the queue for real-time monitoring of the quench condition. The update_get function is responsible for extracting the latest "sample length" and "quench criterion" values from the queue, and saving the power supply voltage and power supply current data read by the update_TDK thread and the voltage data of the second measuring device 41 read by the update_aVoltage thread in real time.

[0049] When the voltage measured by the second measuring device 41 first exceeds the set quench criterion, the host computer 60 will automatically set the target current of the power supply to zero, and capture the current value, which is displayed in the critical current value box of the interface of the measurement operating end. At the same time, the interface will display a quench alarm prompt. The power supply will gradually decrease to zero according to the set current fall rate. During the whole process, the host computer 60 continuously collects the power supply voltage, power supply current and voltage data of the measured strip 11 in real time.

[0050] After clicking the "stop" button on the measurement operating end, the measurement operating end will pop up a file selection dialog box, allowing the user to select the save path and file name. After stopping, the data collection will end, the power supply will continue to decrease to zero according to the set fall rate, and the system will enter the stop state.

[0051] In the description of the application, it needs to be explained that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0052] In addition, the terms "horizontal", "vertical", "overhang" and the like do not mean that the component must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0053] In the description of the application, it also needs to be explained that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0054] The above is only the preferred embodiment of the application and is not intended to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

Claims

1. A superconducting tape testing apparatus, characterized by, The application relates to a superconducting tape testing device, comprising: a fixing unit for fixing a to-be-tested tape, wherein the to-be-tested tape has at least one joint; a current input unit comprising a power supply which is electrically connected to the to-be-tested tape through two current leads, wherein the two current leads are located on two sides of the joint and are connected to two first connection points of the to-be-tested tape; a current detection unit comprising a shunt resistor connected in series to one of the current leads and a first measuring device connected to the shunt resistor; a voltage detection unit comprising a second measuring device connected to the to-be-tested tape through two voltage leads, wherein the two voltage leads are located on the two sides of the joint and are connected to two second connection points of the to-be-tested tape which are located inside the two first connection points; a cold source in contact with the to-be-tested tape.

2. The superconducting tape testing apparatus of claim 1, wherein, The current leads are connected to the to-be-tested tape through a pressure contact structure.

3. The superconducting tape testing apparatus of claim 1, wherein, The voltage leads are welded to the to-be-tested tape.

4. The superconducting tape testing device according to claim 1, wherein the cold source comprises a liquid nitrogen container containing liquid nitrogen, and the fixing unit is arranged in the liquid nitrogen container, and the superconducting tape is immersed in the liquid nitrogen.

5. The superconducting tape testing apparatus of claim 4, wherein, The fixing unit comprises a tape bearing part and a supporting part, one end of the supporting part is fixedly connected to the bearing part, and the other end of the supporting part is connected to a side wall or a cover of the liquid nitrogen container.

6. The superconducting tape testing apparatus of claim 5, wherein, The supporting part comprises a feed-through electrode which penetrates through the liquid nitrogen container and is electrically connected to the tape bearing part, the tape bearing part is electrically connected to the to-be-tested tape, and the feed-through electrode is electrically connected to the current lead.

7. The superconducting tape testing apparatus of claim 2, wherein, The cold source further comprises a refrigerator and a cold conducting structure, one end of the cold conducting structure is connected to a cold head of the refrigerator, and the other end of the cold conducting structure is in contact with a pressure contact area of the current lead on the to-be-tested tape.

8. The superconducting tape testing apparatus of claim 7, wherein, The pressure contact structure comprises a pressing sheet and a pressure contact solder, the pressure contact solder is arranged between the to-be-tested tape and the current lead, the pressing sheet is used for pressing the to-be-tested tape, the pressure contact solder and the current lead, the pressure contact structure further comprises a heat capacity sheet arranged between the pressure contact solder and the current lead or between the pressure contact solder and the to-be-tested tape, and the other end of the cold conducting structure is in contact with the heat capacity sheet.

9. A superconducting tape measurement system characterized by, The application further relates to a superconducting tape testing system comprising a host computer and the superconducting tape testing device according to any one of claims 1-8, and the host computer is in communication connection with the first measuring device, the second measuring device and the power supply respectively.

10. The superconducting tape measurement system of claim 9, wherein, The host computer further comprises a measurement operation end for setting a measurement parameter and displaying a measurement result.

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