Device for testing electrical strength of vacuum insulating material

Abstract

The invention relates to the technical field of electrical strength testing, in particular to a vacuum insulating material electrical strength testing device. Comprising a vacuum cavity provided with a vacuum gauge and a test cable, electrode ends of a tested sample and the test cable are arranged on the inner side of the vacuum cavity, one end of the tested sample is connected with the electrode end of the test cable, and the other end of the tested sample is arranged on a mobile grounding assembly; the vacuum assembly comprises a molecular pump and a proportional valve which are respectively communicated with the vacuum cavity, and a first isolating valve is communicated between the molecular pump and the vacuum cavity. The sample to be tested is placed in the vacuum cavity, the voltage module, the molecular pump, the first isolation valve and the proportional valve are controlled through the controller, the vacuum environment is directly simulated in the vacuum cavity, the problem that the surface of the sample is polluted due to the fact that insulating oil is used in a traditional method is solved, the sample is free of pollution, and follow-up recycling and reusing are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical strength testing, and particularly to an electrical strength testing device for vacuum insulation materials. Background Art

[0002] Due to its good insulation properties, vacuum insulation materials are widely used in fields such as aerospace and high-energy physics experiments. In order to ensure the practicality of vacuum insulation materials, it is necessary to detect the electrical strength of vacuum insulation materials. Generally, when performing high-intensity electrical strength testing on vacuum insulation materials, the sample to be tested needs to be placed in insulating oil. However, in this way, the surface of the vacuum insulation material is covered with insulating oil, causing contamination of the sample to be tested and making it difficult to clean and recycle. Summary of the Invention

[0003] In view of this, the present invention provides an electrical strength testing device for vacuum insulation materials to solve the problems.

[0004] The present invention provides an electrical strength testing device for vacuum insulation materials, comprising:

[0005] A vacuum chamber, provided with a vacuum gauge and a test cable, the electrode ends of the sample to be tested and the test cable are arranged inside the vacuum chamber, one end of the sample to be tested is connected to the electrode end of the test cable, and the other end is arranged on a movable grounding assembly;

[0006] A vacuum assembly, comprising a molecular pump and a proportional valve respectively communicating with the vacuum chamber, and a first isolation valve is communicated between the molecular pump and the vacuum chamber;

[0007] A voltage module, connected to the test cable, adapted to apply a voltage to the test cable up to a target voltage;

[0008] A controller, electrically connected to the vacuum gauge, the voltage module, the molecular pump, the first isolation valve and the proportional valve respectively, adapted to adjust the vacuum degree in the vacuum chamber to a target vacuum degree in real time, and also adapted to collect the output voltage of the voltage module in real time.

[0009] In the present invention, the sample to be measured is placed in a vacuum chamber. The voltage module, molecular pump, first isolation valve, and proportional valve are controlled by a controller to directly simulate a vacuum environment in the vacuum chamber, avoiding the problem of sample surface contamination caused by the use of insulating oil in traditional methods. This enables the sample to be pollution-free and facilitates subsequent recycling and reuse. High voltages can be applied in a vacuum environment, effectively enhancing the ability to detect electrical strength, thereby enabling a more accurate assessment of the performance of vacuum insulation materials. The controller can adjust the vacuum degree inside the vacuum chamber in real time and collect the output voltage of the voltage module in real time, ensuring the controllability and accuracy of the test process. By connecting the molecular pump and proportional valve, the vacuum degree can be adjusted according to the test requirements to simulate various conditions in the actual working environment, thereby improving the applicability and effectiveness of the test. The controller collects the output voltage of the voltage module in real time and can promptly determine whether the sample to be measured is broken down based on the voltage abnormality during the test process.

[0010] In an alternative embodiment, the voltage module includes a current sensor electrically connected to the controller. The current sensor is adapted to detect the current signal on the test cable, and the controller is adapted to collect the current signal of the current sensor in real time.

[0011] The current sensor in the present invention enables the controller to detect and monitor the current signal on the test cable in real time, thus providing more comprehensive data support for the electrical strength test. By collecting the current signal in real time, the controller can promptly determine whether the sample to be measured is broken down based on the current abnormality during the test process. Combining the current and voltage data, the controller can more accurately evaluate the electrical performance of the measured vacuum insulation material, including its breakdown threshold and voltage-bearing capacity, improving the accuracy and reliability of the test. The controller has the function of collecting current signals and output voltages, which can not only monitor the test process in real time but also provide a more detailed basis for evaluating the material performance in subsequent data analysis, helping researchers more comprehensively understand the electrical characteristics of the material.

[0012] In an alternative embodiment, it further includes:

[0013] A mass spectrometer, connected to the vacuum chamber, is adapted to detect the gas type in the vacuum chamber in real time.

[0014] During the electrical strength test, if breakdown or discharge occurs, the mass spectrometer can detect in real time the gas components generated in the vacuum chamber, providing direct evidence for analyzing the electrical properties of the vacuum insulation material and its failure mechanism. For example, it can be determined which substance in the vacuum insulation material has broken down based on the test results of the mass spectrometer. By monitoring the gas type in real time, it also helps researchers understand the performance of the material under different atmosphere conditions, further enhancing the scientificity and accuracy of the test results. This information is crucial for evaluating the electrical breakdown resistance of the material. The mass spectrometer can quickly identify unusual gas components. Once abnormal gases (such as toxic or unstable gases) are detected, safety measures can be taken promptly, enhancing the safety of the test process. By adjusting the gas components and types in the chamber and the vacuum conditions, the electrical strength of the material under different environments can be evaluated, making the test more in line with the requirements of actual application scenarios.

[0015] In an alternative embodiment, it further includes:

[0016] An imaging lens group, connected to the vacuum chamber, adapted to take real-time pictures of the sample to be tested in the vacuum chamber.

[0017] The imaging lens group can record in real time the state of the sample during the test, including any possible physical changes or defects, such as cracks, deformations, or breakdown discharges. This provides an intuitive visual basis for subsequent analysis. Through real-time shooting, researchers can dynamically observe the performance of the sample to be tested under different voltage conditions, providing important information for understanding the behavior of the material under actual working conditions and enhancing the comprehensiveness of the data. When electrical breakdown or other abnormal conditions occur, the image record can help analyze the cause of the accident, identify factors that may lead to failure, and thus improve the material or the test method.

[0018] In an alternative embodiment, the vacuum assembly further includes:

[0019] A mechanical pump, communicating with the vacuum chamber;

[0020] A second isolation valve, communicatively disposed between the vacuum chamber and the mechanical pump;

[0021] Both the mechanical pump and the second isolation valve are electrically connected to the controller.

[0022] The connection between the mechanical pump and the vacuum chamber allows for the rapid and effective extraction of air inside the vacuum chamber to achieve the purpose of the first-stage vacuum pumping. The second isolation valve can form an airtight partition between the mechanical pump and the vacuum chamber after the first-stage vacuum pumping, effectively keeping the vacuum chamber in a vacuum state without being affected by the external environment and ensuring the stability of the test conditions.

[0023] In an alternative embodiment, the inlet end of the molecular pump is communicated with the first isolation valve, and the outlet end of the molecular pump is communicated with the inlet end of the mechanical pump.

[0024] Connecting the inlet end of the molecular pump to the first isolation valve can close the first isolation valve after the molecular pump evacuates the vacuum chamber, thus achieving effective isolation between the inside and outside of the vacuum chamber and preventing external gas from entering. Connecting the outlet end of the molecular pump to the inlet end of the mechanical pump can evacuate the outlet end of the molecular pump through the mechanical pump, enabling the molecular pump to reach the operating vacuum condition, so that the molecular pump can evacuate the vacuum chamber.

[0025] In an alternative embodiment, the vacuum assembly further includes:

[0026] A third isolation valve, which is communicatively arranged between the molecular pump and the mechanical pump;

[0027] The third isolation valve is electrically connected to the controller;

[0028] The outlet end of the molecular pump is communicated with one end of the third isolation valve, and the other end of the third isolation valve is communicated with the inlet end of the mechanical pump.

[0029] When the third isolation valve is opened, the mechanical pump can evacuate the outlet end of the molecular pump, enabling the molecular pump to reach the operating vacuum condition. By electrically connecting the third isolation valve to the controller, automatic control can be achieved, allowing the system to automatically adjust the opening and closing of the valve according to the vacuum state, improving work efficiency.

[0030] In an alternative embodiment, it further includes: a vacuum relief valve, which is communicated with the inside of the vacuum chamber, and the vacuum relief valve is electrically connected to the controller.

[0031] The vacuum relief valve can enable the vacuum chamber to quickly release vacuum as needed, effectively preventing equipment damage or sample damage caused by excessive vacuum. Electrically connecting the vacuum relief valve to the controller can achieve automatic control. During the operation of the system, the controller can open the vacuum relief valve when detecting an abnormal pressure value, thereby keeping the pressure inside the system within a safe range.

[0032] In an alternative embodiment, the movable grounding assembly includes:

[0033] A movable frame, made of metal, is arranged inside the vacuum chamber. The movable frame includes a connecting portion and an abutting portion connected to the connecting portion, and a threaded hole is provided on the connecting portion;

[0034] Multiple connecting blind holes are distributed along the extending direction of the measured sample and are adapted to be bolt-connected to the threaded hole;

[0035] The sample to be measured is abutted between the electrode end of the test cable and the abutting part.

[0036] The distance between the moving frame and the electrode end of the test cable can be adjusted according to the length of the sample to be measured, so that the sample to be measured is abutted between the electrode end of the test cable and the abutting part.

[0037] In an optional embodiment, an observation window is provided on the side wall of the vacuum chamber. Description of the Drawings

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 Structural schematic diagram of an embodiment of the present invention;

[0040] Figure 2 Schematic diagram of the electrode end position of an embodiment of the present invention;

[0041] Figure 3 Structural schematic diagram of the vacuum assembly of an embodiment of the present invention;

[0042] Figure 4 Physical diagram of an embodiment of the present invention;

[0043] Figure 5 Schematic diagram of the human-machine interaction interface of an embodiment of the present invention.

[0044] Description of the reference numerals:

[0045] 1. Vacuum chamber; 2. Electrode end; 3. Sample to be measured; 4. Molecular pump; 5. Proportional valve; 6. First isolation valve; 7. Controller; 8. Mechanical pump; 9. Second isolation valve; 10. Third isolation valve; 11. Vacuum relief valve; 12. Moving frame; 13. Observation window; 14. Test cable. Detailed Embodiments

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0047] Vacuum materials refer to a class of materials that are used in a vacuum environment and possess specific properties to meet corresponding functional requirements. In the field of functional materials, for example, the ceramic materials used in vacuum electronic devices not only need to have good insulation performance to ensure electrical isolation between electronic components, but also need to adapt to temperature changes, radiation effects, etc. in a vacuum environment to ensure the stable transmission of electronic signals. At the same time, some rubber materials used for sealing high-vacuum systems, such as fluororubber, have a unique molecular structure that enables them to maintain good elasticity and sealing performance in a vacuum environment, preventing external gas from infiltrating and ensuring the stability of the vacuum state of the system. From the perspective of material composition, it includes different types such as metals, ceramics, and polymer polymers. Metal materials are often used to construct the framework of vacuum containers due to their excellent mechanical properties and thermal conductivity; ceramic materials are preferred for the support and insulation protection of electronic components due to their excellent insulation and high-temperature resistance; polymer polymer materials play a role in vacuum sealing, flexible electronic devices, etc. by utilizing their own flexibility and easy processing. Generally speaking, vacuum materials are collectively referred to as those materials that are specially designed, processed, or selected to work reliably under vacuum conditions and achieve various functions such as maintaining vacuum degree, ensuring electrical performance, and withstanding mechanical effects.

[0048] The insulation performance of vacuum materials has crucial significance in specific fields. In the aerospace field, spacecraft navigate in the vast universe where the space environment is approximately vacuum. A large number of sophisticated electronic devices and systems are carried inside the spacecraft, and the normal operation of these devices depends on the insulation barrier constructed by vacuum materials. Due to the strong cosmic ray radiation and extremely large temperature differences, in a vacuum environment, if the insulation performance of vacuum materials is poor, electronic devices are extremely vulnerable to interference. In the field of high-energy physics experiments, such as large particle accelerators, the experimental environment usually requires a high degree of vacuum. There are ultra-high-energy particle beams inside the accelerator, and the operating voltage is extremely high. At this time, the insulation performance of the vacuum materials around the particle acceleration orbit and various detection devices is the key to the smooth progress of the experiment. If there are weak links in insulation, it may cause partial discharge, which will not only damage expensive experimental equipment, causing huge economic losses, but also interfere with the precise control of particle beams, resulting in deviations in experimental data. In the scope of high-end scientific research instruments such as electron microscopes, in order to achieve high-resolution imaging at the atomic level, the working chamber is often in a vacuum state. The electron optical system inside the instrument has extremely high requirements for voltage stability. As a key part for isolating electric field interference, if the insulation performance of vacuum materials is insufficient, the focusing of the electron beam will be affected, and the image resolution will be greatly reduced, unable to provide accurate microscopic structure information. Moreover, in some special industrial production processes, such as vacuum coating processes, it is necessary to precisely control the electric field in a vacuum environment to achieve high-quality film deposition. If the insulation of vacuum materials is not good, problems such as electric field leakage and non-uniformity will occur during the coating process, resulting in uneven coating quality, increased product rejection rate, and increased production costs.

[0049] Existing equipment for measuring the electrical insulation strength of materials includes dielectric strength testers, withstand voltage testers, electrical strength testers for solid insulating materials, etc. The basic structures of these devices are similar, mainly consisting of a voltage boosting part, a control part, a display circuit, measuring fixtures, etc. However, the following problems exist:

[0050] (1) The problem of sample contamination in high-voltage testing. Traditional equipment can achieve electrical strength testing up to several tens of kV. If higher-strength testing is required, the sample needs to be connected to the high-voltage electrode and placed in insulating oil, which will cause the inner and outer surfaces of the sample to be covered with insulating oil, resulting in sample contamination and making it difficult to clean and recycle.

[0051] (2) Limited ability to simulate the test environment. Similarly, affected by the relatively low air insulation strength, it is difficult to simulate the electrical strength performance of the sample under various complex actual working conditions by using the method of immersing in insulating oil, and it cannot meet the requirements of vacuum insulating materials and high-end application scenarios.

[0052] (3) The test content that can be achieved is single. The current electrical strength tester for insulating materials can only achieve testing under a certain loading time and a certain voltage, and can record the changes of parameters such as current and voltage during the test process.

[0053] To achieve the testing of the electrical strength of vacuum insulating materials, the present invention provides an electrical strength testing device based on a vacuum chamber. Different from the traditional electrical strength tester for insulating materials that immerses the sample in insulating oil, the present invention configures a vacuum chamber that can achieve a vacuum degree of up to the order of 10 -5 Pa, and places the vacuum insulating material sample in the vacuum chamber to directly simulate the working environment of the vacuum insulating material.

[0054] The following will describe the embodiments of the present invention in conjunction with Figures 1 to 5 , and describe the embodiments of the present invention.

[0055] According to an embodiment of the present invention, there is provided an electrical strength testing device for vacuum insulating materials, including:

[0056] Vacuum chamber 1 is provided with a vacuum gauge and a test cable 14. The electrode end 2 of the sample under test 3 and the test cable 14 is arranged inside the vacuum chamber 1. One end of the sample under test 3 is connected to the electrode end 2 of the test cable 14, and the other end is arranged on a movable grounding assembly; the vacuum chamber 1 can be integrally made of stainless steel, with multiple flange interfaces reserved. The flange interfaces can be respectively provided with a vacuum relief valve 11, a proportional valve 5, a mass spectrometer and an imaging lens group. The vacuum chamber 1 can also be provided with an interface for introducing the test cable 14, and the electrode end 2 of the test cable 14 is arranged inside the vacuum chamber 1 through the cable introduction interface. The sample under test 3 can be a vacuum insulating material in the shape of a sheet, strip, cylinder or other various shapes. The movable grounding assembly can have the functions of clamping and grounding. The movable grounding assembly is connected to the vacuum chamber 1, and the vacuum chamber 1 is grounded.

[0057] Vacuum assembly, including a molecular pump 4 and a proportional valve 5 respectively communicating with the vacuum chamber 1. A first isolation valve 6 is communicated between the molecular pump 4 and the vacuum chamber 1; the molecular pump 4 and the vacuum chamber 1 can be connected through a pipeline, and the first isolation valve 6 can be a gate valve. When the molecular pump 4 evacuates the vacuum chamber 1, the first isolation valve 6 is opened. After the molecular pump 4 finishes evacuating the vacuum, the first isolation valve 6 is closed, so that the inside of the vacuum chamber 1 maintains a vacuum state.

[0058] Voltage module, connected to the test cable 14, suitable for pressurizing the test cable 14 to a target voltage, and can complete an electrical strength test of up to 150 kV at most;

[0059] Controller 7 is respectively electrically connected to the vacuum gauge, the voltage module, the molecular pump 4, the first isolation valve 6 and the proportional valve 5, suitable for adjusting the vacuum degree inside the vacuum chamber 1 to the target vacuum degree in real time, and also suitable for collecting the output voltage of the voltage module in real time. It should be noted that the controller 7 can control the voltage module to pressurize the test cable 14. The target voltage can be set in the controller 7, and the boost rate and the maintenance time of the target voltage can be controlled. The target vacuum degree and the target voltage can be specific values or a certain range. The controller 7 can adjust the vacuum degree inside the vacuum chamber 1 by controlling the opening and closing of the molecular pump 4 and the proportional valve 5. The controller 7 can be an integrated controller 7, and the voltage module is arranged inside the controller 7. The controller 7 can control the proportional valve 5 to adjust the vacuum degree inside the vacuum chamber in real time.

[0060] It should be noted that the controller 7 can record the output voltage of the voltage module to the test cable 14. If it drops abnormally during the target voltage maintenance stage (such as the drop exceeds 20% of the target voltage), it can be considered that the material under test is broken down, and the controller 7 can regard it as a breakdown signal.

[0061] The present invention places the sample 3 to be measured in the vacuum chamber 1, and controls the voltage module, the molecular pump 4, the first isolation valve 6 and the proportional valve 5 through the controller 7, directly simulating the vacuum environment in the vacuum chamber 1, avoiding the problem of sample surface contamination caused by the use of insulating oil in the traditional method, enabling the sample to be pollution-free and facilitating subsequent recovery and reuse. It can apply a high voltage in the vacuum environment, effectively improving the ability of electrical strength detection, and thus being able to more accurately evaluate the performance of vacuum insulation materials. The controller 7 can adjust the vacuum degree inside the vacuum chamber 1 in real time and collect the output voltage of the voltage module in real time, ensuring the controllability and accuracy of the test process. Through the connected molecular pump 4 and proportional valve 5, the vacuum degree can be adjusted according to the test requirements to simulate various conditions in the actual working environment, thereby improving the applicability and effectiveness of the test. The controller 7 collects the output voltage of the voltage module in real time and can timely judge whether the sample 3 to be measured is broken down according to the voltage abnormality during the test process.

[0062] In an alternative embodiment, the voltage module includes a current sensor electrically connected to the controller 7, the current sensor is adapted to detect the current signal on the test cable 14, and the controller 7 is adapted to collect the current signal of the current sensor in real time. It should be noted that the controller 7 can record the current signal of the current sensor. When the current value exceeds a preset threshold (such as 1 mA), it can be considered that the material to be measured is broken down, and the controller 7 can regard it as a breakdown signal. When it is determined that the material to be measured is broken down, the voltage output of the voltage module can be immediately cut off.

[0063] The current sensor in the present invention enables the controller 7 to detect and monitor the current signal on the test cable 14 in real time, thus providing more comprehensive data support for the electrical strength test. By collecting the current signal in real time, the controller 7 can timely judge whether the sample 3 to be measured is broken down according to the current abnormality during the test process. Combining the current and voltage data, the controller 7 can more accurately evaluate the electrical performance of the vacuum insulation material to be measured, including its breakdown threshold and voltage-bearing capacity, improving the accuracy and reliability of the test. The controller 7 has the functions of collecting current signals and output voltages, which can not only monitor the test process in real time, but also provide a more detailed basis for evaluating the material performance in subsequent data analysis, helping researchers to more comprehensively understand the electrical characteristics of the material.

[0064] In an alternative embodiment, it further includes:

[0065] A mass spectrometer, connected to the vacuum chamber 1, adapted to detect the gas type in the vacuum chamber 1 in real time. The mass spectrometer can be electrically connected to the controller 7 and can start working after breakdown occurs.

[0066] During the electrical strength test, if breakdown or discharge occurs, the mass spectrometer can detect in real time the gas components generated inside the vacuum chamber 1, providing direct evidence for analyzing the electrical properties of the vacuum insulation material and its failure mechanism. For example, it can be determined which substance in the vacuum insulation material has broken down based on the test results of the mass spectrometer. By monitoring the gas type in real time, it also helps researchers understand the performance of the material under different atmospheric conditions, further enhancing the scientific nature and accuracy of the test results. This information is crucial for evaluating the electrical breakdown resistance of the material. The mass spectrometer can quickly identify unusual gas components. Once abnormal gases (such as toxic or unstable gases) are detected, safety measures can be rapidly taken, enhancing the safety of the test process. The electrical strength of the material under different environments can be evaluated by adjusting the gas components and types as well as the vacuum conditions in the chamber, making the test more in line with the requirements of actual application scenarios.

[0067] In an alternative embodiment, it further includes:

[0068] An imaging lens group, specifically a camera, is provided on the vacuum chamber 1 and is adapted to take real-time pictures of the sample 3 to be measured inside the vacuum chamber 1.

[0069] The imaging lens group can record in real time the state of the sample during the test, including any possible physical changes or defects, such as cracks, deformations, or breakdown discharges, and record the discharge location when the discharge occurs. This provides an intuitive visual basis for subsequent analysis. Through real-time shooting, researchers can dynamically observe the performance of the sample 3 to be measured under different voltage conditions, providing important information for understanding the behavior of the material under actual working conditions and enhancing the comprehensiveness of the data. In the event of electrical breakdown or other abnormal situations, the image record can help analyze the cause of the accident, identify factors that may lead to failure, and thus improve the material or the test method.

[0070] In an alternative embodiment, the vacuum assembly further includes:

[0071] A mechanical pump 8, which can be a backing pump, is connected to the vacuum chamber 1;

[0072] A second isolation valve 9 is connected and arranged between the vacuum chamber 1 and the mechanical pump 8;

[0073] Both the mechanical pump 8 and the second isolation valve 9 are electrically connected to the controller 7. The second isolation valve 9 can be a roughing valve.

[0074] The connection between the mechanical pump 8 and the vacuum chamber 1 allows for the rapid and effective extraction of the air inside the vacuum chamber 1 to achieve the purpose of evacuating the vacuum in the first stage. The second isolation valve 9 can form an airtight partition between the mechanical pump 8 and the vacuum chamber 1 after the evacuation in the first stage, effectively enabling the vacuum chamber 1 to maintain the vacuum state without being affected by the external environment and ensuring the stability of the test conditions.

[0075] In an alternative embodiment, the inlet end of the molecular pump 4 is connected to the first isolation valve 6, and the outlet end of the molecular pump 4 is connected to the inlet end of the mechanical pump 8.

[0076] Connecting the inlet end of the molecular pump 4 to the first isolation valve 6 allows for effective isolation between the inside and outside of the vacuum chamber 1 by closing the first isolation valve 6 after the molecular pump 4 evacuates the vacuum chamber 1, preventing external gas from entering. Connecting the outlet end of the molecular pump 4 to the inlet end of the mechanical pump 8 enables the mechanical pump 8 to evacuate the outlet end of the molecular pump 4, so that the vacuum degree in the inner cavity of the molecular pump 4 can reach the vacuum condition for the molecular pump 4 to start, thereby enabling the molecular pump 4 to evacuate the vacuum chamber 1. The molecular pump 4 and the mechanical pump 8 can evacuate the vacuum chamber 1 separately, allowing for a wider range of pressure regulation. The combined evacuation of the molecular pump 4 and the mechanical pump 8 can achieve a relatively high vacuum degree, while the mechanical pump 8 alone can achieve a relatively low vacuum degree.

[0077] In an alternative embodiment, the vacuum assembly further includes:

[0078] A third isolation valve 10, which can be a foreline valve, is connected and arranged between the molecular pump 4 and the mechanical pump 8;

[0079] The third isolation valve 10 is electrically connected to the controller 7;

[0080] The outlet end of the molecular pump 4 is connected to one end of the third isolation valve 10, and the other end of the third isolation valve 10 is connected to the inlet end of the mechanical pump 8.

[0081] When the third isolation valve 10 is opened, the mechanical pump 8 can evacuate the outlet end of the molecular pump 4, so that the vacuum degree in the inner cavity of the molecular pump 4 can reach the vacuum condition for the molecular pump 4 to start. By electrically connecting the third isolation valve 10 to the controller 7, automatic control can be achieved, allowing the system to automatically adjust the opening and closing of the valve according to the vacuum state and improving work efficiency.

[0082] Specifically, when evacuating the vacuum, the second isolation valve 9 and the third isolation valve 10 can be opened first, the first isolation valve 6 and the molecular pump 4 can be closed, and then the mechanical pump 8 can be opened to conduct the first-stage evacuation of the vacuum chamber 1 until the air pressure in the vacuum chamber 1 reaches within 10 Pa, and the vacuum degree of the inner cavity of the molecular pump 4 reaches the vacuum condition for starting the molecular pump 4, which also means that the adjustment range of the vacuum degree of the mechanical pump 8 can be from 100 Pa to 10 Pa. Then, the second-stage evacuation is carried out. The second isolation valve 9 is closed, the first isolation valve 6 and the molecular pump 4 are opened until the vacuum degree in the vacuum chamber 1 reaches the preset range, which can reach 10e-5 Pa. When it is necessary to reduce the vacuum degree in the vacuum chamber 1, it can be adjusted by controlling the proportional valve 5; when it is necessary to increase the vacuum degree in the vacuum chamber 1, the second-stage evacuation can be carried out.

[0083] In an alternative embodiment, it further includes:

[0084] A vacuum relief valve 11, which can be an exhaust valve, is connected to the inner side of the vacuum chamber 1, and the vacuum relief valve 11 is electrically connected to the controller 7.

[0085] The vacuum relief valve 11 enables the vacuum chamber 1 to quickly release the vacuum as needed, effectively preventing equipment damage or sample damage caused by excessive vacuum degree. Electrically connecting the vacuum relief valve 11 to the controller 7 can achieve automatic control. During the operation of the system, the controller 7 can open the vacuum relief valve 11 when detecting an abnormal pressure value, thereby maintaining the pressure in the system within a safe range.

[0086] In an alternative embodiment, the movable grounding assembly includes:

[0087] A movable frame 12, made of metal, is disposed in the vacuum chamber 1. The movable frame 12 includes a connecting portion and a contacting portion connected to the connecting portion, and a threaded hole is provided on the connecting portion;

[0088] Connecting blind holes, which are multiple and distributed along the extending direction of the measured sample 3, and are adapted to be connected to the threaded hole by bolts;

[0089] The measured sample 3 is in contact between the electrode end 2 of the test cable 14 and the contacting portion.

[0090] The distance between the moving bracket 12 and the electrode end 2 of the test cable 14 can be adjusted according to the length of the sample 3 to be measured, so that the sample 3 to be measured is abutted between the electrode end 2 of the test cable 14 and the abutting portion. Specifically, the electrode end 2 of the test cable 14 can be fixed on the inner wall of the vacuum chamber 1. The connecting blind holes are distributed between the moving bracket 12 and the electrode end 2 of the test cable 14. According to the length of the sample 3 to be measured, the threaded hole can be matched with the corresponding connecting blind hole. After being connected by bolts, the distance between the moving bracket 12 and the electrode end 2 of the test cable 14 can be adjusted, so that the sample 3 to be measured is abutted between the electrode end 2 of the test cable 14 and the abutting portion.

[0091] A receiving portion can also be arranged on the abutting portion, and the receiving portion supports the sample 3 to be measured.

[0092] In an optional embodiment, an observation window 13 is provided on the side wall of the vacuum chamber 1, which can be a glass window.

[0093] A man-machine interface can be arranged on the controller 7 to control the vacuum gauge, voltage module, molecular pump 4, first isolation valve 6, proportional valve 5, second isolation valve 9, third isolation valve 10, mass spectrometer, mechanical pump 8 and vacuum relief valve 11.

[0094] During the test, the sample 3 to be measured is installed in the vacuum chamber 1 and abutted between the electrode end 2 of the test cable 14 and the abutting portion; the molecular pump 4 is started, and according to the test requirements, the required target vacuum degree is set on the controller 7. After the system vacuum degree is stable, the test is prepared; the target voltage, voltage rise rate and maintenance time are set according to the test requirements, and the pressurization is started; the camera records the real-time image of the sample 3 to be measured inside the vacuum chamber 1 in real time; if a breakdown discharge phenomenon occurs, the mass spectrometer is turned on for testing, and the test results of the mass spectrometer are recorded.

[0095] In the present invention, the sample 3 to be measured is placed in the vacuum chamber 1, and the electrical strength test with a maximum of 150 kV can be realized. The sample is pollution-free and recyclable; the vacuum degree in the vacuum chamber 1 can be regulated by introducing gas through the proportional valve 5, and different atmosphere environments can also be created to simulate the environment. In addition, electromagnetic interference, temperature and other accessories can be added to realize more complex environment simulation; in addition to realizing the tests of current and voltage, a camera capable of recording the breakdown moment and the surface flashover image, and a mass spectrometer capable of recording the gas components generated after the material is broken down are also equipped.

[0096] Although the embodiments of the present invention are described with reference to the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An electrical strength test device for vacuum insulation materials, characterized in that Comprising: A vacuum chamber (1) provided with a vacuum gauge and a test cable (14). The electrode end (2) of the sample under test (3) and the test cable (14) is arranged inside the vacuum chamber (1). One end of the sample under test (3) is connected to the electrode end (2) of the test cable (14), and the other end is arranged on a movable grounding assembly. A vacuum assembly including a molecular pump (4) and a proportional valve (5) respectively communicating with the vacuum chamber (1). A first isolation valve (6) is communicated between the molecular pump (4) and the vacuum chamber (1). A voltage module connected to the test cable (14) and adapted to pressurize the test cable (14) to a target voltage. A controller (7) electrically connected to the vacuum gauge, the voltage module, the molecular pump (4), the first isolation valve (6), and the proportional valve (5) respectively, and adapted to adjust the vacuum degree in the vacuum chamber (1) to a target vacuum degree in real time, and also adapted to collect the output voltage of the voltage module in real time.

2. The electrical strength testing device for vacuum insulation materials according to claim 1, characterized in that The voltage module includes a current sensor electrically connected to the controller (7). The current sensor is adapted to detect the current signal on the test cable (14), and the controller (7) is adapted to collect the current signal of the current sensor in real time.

3. The electrical strength testing device for vacuum insulation material according to claim 1, characterized in that, Also comprising: A mass spectrometer connected to the vacuum chamber (1) and adapted to detect the gas type in the vacuum chamber (1) in real time.

4. The electrical strength testing device for vacuum insulation materials according to claim 1, wherein Also comprising: An imaging lens group connected to the vacuum chamber (1) and adapted to take a real-time picture of the sample under test (3) in the vacuum chamber (1).

5. The electrical strength testing device for vacuum insulation materials according to claim 1, characterized in that The vacuum assembly further includes: A mechanical pump (8) communicating with the vacuum chamber (1). A second isolation valve (9) communicatively arranged between the vacuum chamber (1) and the mechanical pump (8). Both the mechanical pump (8) and the second isolation valve (9) are electrically connected to the controller (7).

6. The electrical strength testing device for vacuum insulation materials according to claim 5, wherein, The inlet end of the molecular pump (4) communicates with the first isolation valve (6), and the outlet end of the molecular pump (4) communicates with the inlet end of the mechanical pump (8).

7. The electrical strength testing device for vacuum insulation materials according to claim 5, characterized in that, The vacuum assembly further includes: A third isolation valve (10) communicatively arranged between the molecular pump (4) and the mechanical pump (8). The third isolation valve (10) is electrically connected to the controller (7). The outlet end of the molecular pump (4) communicates with one end of the third isolation valve (10), and the other end of the third isolation valve (10) communicates with the inlet end of the mechanical pump (8).

8. The electrical strength testing device for vacuum insulation materials according to claim 1, characterized in that Also comprising: A vacuum relief valve (11) communicating with the inside of the vacuum chamber (1). The vacuum relief valve (11) is electrically connected to the controller (7).

9. The electrical strength testing device for vacuum insulation material according to claim 1, characterized in that, The movable grounding assembly includes: A movable frame (12) made of metal and arranged inside the vacuum chamber (1). The movable frame (12) includes a connecting portion and an abutting portion connected to the connecting portion. A threaded hole is provided on the connecting portion. A plurality of connecting blind holes are distributed along the extending direction of the sample under test (3) and are adapted to be bolt-connected to the threaded hole. The sample under test (3) abuts between the electrode end (2) of the test cable (14) and the abutting portion.

10. The electrical strength testing device for vacuum insulation materials according to claim 1, characterized in that, An observation window (13) is opened on the side wall of the vacuum chamber (1).

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