Voltage breakdown resistance test equipment
By using voltage breakdown testing equipment and the material under test as the test medium, the problem of limited insulator size specifications has been solved, and the testing process has been simplified and costs have been reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-07
- Publication Date
- 2026-04-03
AI Technical Summary
In the existing technology, the size specifications of the insulator are limited by the breakdown voltage of the test medium, which requires the test medium to be replaced multiple times, resulting in cumbersome testing procedures and wasted costs.
A withstand voltage breakdown test device is used. This device uses a molding device to prepare the sample to be tested and uses the sample itself as the test medium. The electrode discharge end spacing L is set to perform the withstand voltage breakdown test, thus avoiding the use of a test medium.
It solves the problems of cumbersome testing procedures and wasteful costs, and avoids the influence of testing media on the results, thus improving the accuracy and efficiency of testing.
Smart Images
Figure CN224081745U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electrical technology, and in particular to a withstand voltage breakdown test device. Background Technology
[0002] In electrical equipment, insulators are commonly used, and different insulators can withstand different breakdown voltages. The breakdown voltage of an insulator is tested through a withstand voltage breakdown test.
[0003] In related technologies, insulating oil or the inert gas sulfur hexafluoride is typically used as the test medium to perform breakdown voltage testing on insulators. Specifically, the insulator under test is placed in the test medium to create an insulating space around it for breakdown voltage testing.
[0004] However, the above testing method has a limitation: the size of the insulator under test is restricted by the breakdown voltage of the test medium. For example, a certain insulating oil has a breakdown voltage of no less than 35KV when the electrode spacing is 2.5mm. Correspondingly, when using this insulating oil as the test medium, the size of the insulator under test cannot exceed 2.5mm. Furthermore, when the breakdown voltage during testing is greater than or equal to 35KV, the insulating oil will break down, while the insulator under test may not. Therefore, it is necessary to change to another test medium to continue the test, resulting in a cumbersome testing procedure and significant cost waste. Utility Model Content
[0005] To address the aforementioned technical problems, this application provides a withstand voltage breakdown test device that avoids the need for multiple changes of the test medium, thus resolving the issues of cumbersome testing procedures and cost waste.
[0006] This application provides a withstand voltage breakdown testing device, the testing device comprising:
[0007] A forming device for preparing a sample to be tested;
[0008] An electrode, comprising an opposing contact end and a discharge end, wherein when the sample to be tested is prepared using the forming device, the discharge end of the electrode is used to be inserted into the sample to be tested through the forming device, wherein there are two electrodes, which are respectively located on opposite sides of the sample to be tested, and the discharge ends of the two electrodes are spaced apart along the extension direction of the electrodes, with a distance L between the discharge ends of the two electrodes.
[0009] A voltage providing device includes a positive voltage output terminal and a negative voltage output terminal. The positive voltage output terminal is connected to a terminal of one electrode, and the negative voltage output terminal is connected to a terminal of another electrode. The voltage providing device is used to provide different test voltages at preset time intervals.
[0010] A voltage detector is connected to the terminals of the two electrodes and is used to detect the real-time voltage value between the terminals of the two electrodes. Based on the real-time voltage value, the distance L, and the test voltage provided by the voltage supply device, it is determined whether the sample under test passes the withstand voltage breakdown test.
[0011] In one embodiment, the molding device includes a first molding body and a second molding body, which are detachably connected together and enclose a first receiving cavity and a second receiving cavity that are interconnected. The second receiving cavity is two in number and distributed on opposite sides of the first receiving cavity. An inlet is provided on the first molding body or the second molding body, which communicates with the first receiving cavity and is used to inject liquid test material into the first receiving cavity. The second receiving cavity is used to accommodate the receiving end of the electrode, and the discharge end of the electrode extends into the first receiving cavity. After solidification, the test material in the first receiving cavity surrounds and connects to the discharge end of the electrode.
[0012] In one embodiment, the first molded body includes a first groove and a second groove that are interconnected, the depth of the first groove being greater than the depth of the second groove, and two second grooves distributed on opposite sides of the first groove; the second molded body includes a third groove and a fourth groove that are interconnected, the depth of the third groove being greater than the depth of the fourth groove, and two fourth grooves distributed on opposite sides of the fourth groove; when the first molded body and the second molded body are connected together, the first groove and the third groove correspondingly enclose to form the first receiving cavity, and the second groove and the fourth groove correspondingly enclose to form the second receiving cavity; the inlet is disposed on the first molded body and communicates with the first groove, or the inlet is disposed on the second molded body and communicates with the second groove; wherein the third groove and the first groove have the same shape and size, and the fourth groove and the second groove have the same shape and size.
[0013] In one embodiment, the inner surfaces of the first groove and the second groove are both arc-shaped surfaces, and the shape of the second groove matches that of the electrode.
[0014] In one embodiment, both the first groove and the second groove are semi-cylindrical grooves.
[0015] In one embodiment, the central axis corresponding to the semi-cylindrical inner wall of the first groove coincides with the central axis corresponding to the semi-cylindrical inner wall of the second groove.
[0016] In one embodiment, the difference between the depth of the first groove and the depth of the second groove is greater than or equal to 5 mm and less than or equal to 15 mm; the difference between the depth of the third groove and the depth of the fourth groove is greater than or equal to 5 mm and less than or equal to 15 mm.
[0017] In one embodiment, two second receiving cavities are symmetrically distributed on opposite sides of the first receiving cavity.
[0018] In one embodiment, the length of the second receiving cavity is 50 mm in the distribution direction of the first receiving cavity and the second receiving cavity.
[0019] In one embodiment, the electrode includes an outer peripheral surface surrounding its own discharge center line, and a first end face and a second end face located at opposite ends of the outer peripheral surface. The outer peripheral surface is a cylindrical surface. The first end face is located in the sample to be tested, and the second end face is located outside the sample to be tested. At least the first end face is a spherical surface, and the outer peripheral surface of the electrode and the first end face are smoothly connected.
[0020] The voltage withstand breakdown testing equipment provided in this application eliminates the need for a test medium during voltage withstand breakdown testing. Instead, the material under test itself serves as the test medium, requiring only the distance L between the discharge terminals of the two electrodes to be set according to the preset test thickness. This avoids the need for multiple changes of the test medium, solving the problems of cumbersome testing procedures and cost waste. Furthermore, the preset test thickness of the material under test is no longer limited by the test medium. It also prevents molecules of the test medium from penetrating into the material under test and affecting the final test results. Attached Figure Description
[0021] Figure 1 This is a cross-sectional schematic diagram of a forming device in a withstand voltage breakdown test equipment provided in an embodiment of this application;
[0022] Figure 2 This is a top view schematic diagram of a first molded body in a molding apparatus provided in an embodiment of this application;
[0023] Figure 3 This is a schematic diagram of the structure when a test sample is tested using a voltage withstand breakdown test device provided in the embodiments of this application;
[0024] Figure 4This is a schematic diagram of the test sample and electrode combination obtained using the molding apparatus provided in the embodiments of this application;
[0025] Figure 5 This is a schematic diagram from another perspective of the test sample and electrode bonding.
[0026] Figure label:
[0027] 10- Molding device, 11- First molding body, 12- Second molding body
[0028] 101 - First receiving cavity, 102 - Second receiving cavity, 103 - Inlet,
[0029] 111 - First groove, 112 - Second groove
[0030] 20 - Electrode, 21 - First end face, 30 - Sample to be tested, 40 - Voltage supply device, 50 - Voltage detector. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0032] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0033] As described in the background section, the testing methods provided in the related technologies have the problem that the size and specifications of the insulator under test are limited by the breakdown voltage of the test medium. As a result, when testing a new insulator under test, it is often necessary to change multiple test media to finally obtain the true breakdown voltage of the insulator under test. This leads to the problem that the breakdown voltage testing process is cumbersome and costly.
[0034] To address the aforementioned technical problems, this application provides a withstand voltage breakdown testing device, as shown in the reference. Figures 1 to 3The testing equipment includes a forming device 10, electrodes 20, a voltage supply device 40, and a voltage detector 50. The forming device 10 is used to prepare the sample 30 to be tested. The electrodes 20 include opposing terminals and discharge terminals. When preparing the sample 30 using the forming device 10, the discharge terminals of the electrodes 20 are inserted into the sample through the forming device 10. There are two electrodes 20, located on opposite sides of the sample 30, with their discharge terminals spaced apart along the extension direction of the electrodes 20. The two electrodes 20 have a spacing L between them; the voltage supply device 40 includes a positive voltage output terminal and a negative voltage output terminal. The positive voltage output terminal is connected to the terminal of one electrode, and the negative voltage output terminal is connected to the terminal of another electrode. The voltage supply device 40 is used to provide different test voltages according to a preset time interval; the voltage detector 50 is connected to the terminals of the two electrodes 20 and is used to detect the real-time voltage value between the terminals of the two electrodes 20, so as to determine whether the sample under test passes the withstand voltage breakdown test based on the real-time voltage value, the spacing L, and the test voltage provided by the voltage supply device.
[0035] Based on the above technical solution, when using the testing equipment provided in this application, the sample to be tested 30 can first be prepared using the forming device 10, and the discharge end of the electrode 20 can be inserted into the sample to be tested 30. Then, the sample to be tested 30 and the electrode 20 are removed from the forming device 10, and the positive voltage output terminal of the voltage providing device 40 is connected to one electrode 20, and the negative voltage output terminal is connected to the other electrode 20, and the voltage detector 50 is connected between the terminals of the two electrodes. The portion of the sample to be tested 30 located between the discharge ends of the two electrodes 20 is the effective test portion for breakdown testing. Besides this effective test portion, the other portions of the sample to be tested 30 can provide an insulating environment. By making the distance L between the discharge ends of the two electrodes 20 equal to the preset test thickness of the material to be tested, the portion of the material to be tested located between the discharge ends of the two electrodes 20 can have a preset test thickness, that is, the effective test portion can have a preset test thickness.
[0036] Then, the voltage supply device 40 can provide different test voltages at preset time intervals and in ascending order. During the test, the voltage detector 50 detects the real-time voltage value between the terminals of the two electrodes, thus performing a withstand voltage breakdown test on the effective test part. For example, the preset time interval is 2 minutes, and the test voltage starts from 1KV, increasing by 0.5KV every 2 minutes. That is, first, a test voltage of 1KV is provided and held for 2 minutes, then a test voltage of 1.5KV is provided and held for 2 minutes, and then a test voltage of 2KV is provided and held for 2 minutes. If, during a certain current test voltage holding period, the real-time voltage value is equal to the test voltage provided by the voltage supply device, it indicates that the effective test part with thickness L has not been broken down, and the effective test part has passed the withstand voltage breakdown test of the current test voltage. If, during a certain current test voltage holding period, the real-time voltage value rapidly decreases and approaches zero, it indicates that the effective test part with thickness L has been broken down, and the effective test part has not passed the withstand voltage breakdown test of the current test voltage. For example, if an effective test section with thickness L passes the 20kV withstand voltage breakdown test but fails the 25kV withstand voltage breakdown test, it indicates that the breakdown voltage of the effective test section with thickness L is between 20kV and 25kV. Then, within the 20kV to 25kV range, multiple test voltages can be selected with smaller gradients, and the test can be repeated. By repeatedly decreasing the gradient of the test voltage increase (e.g., changing from increasing by 5kV every 2 minutes to increasing by 1kV every 2 minutes), the accurate breakdown voltage of the effective test section with thickness L can be obtained.
[0037] As described above, with the testing equipment provided in this application, when performing withstand voltage breakdown tests on the material under test, a test medium is no longer required; instead, the material under test itself can serve as the test medium. Only the distance L between the discharge ends of the two electrodes 20 needs to be set according to the preset test thickness. This avoids the need for multiple changes of the test medium, solving the problems of cumbersome testing procedures and cost waste. Furthermore, the preset test thickness of the material under test is no longer limited by the test medium. It also prevents molecules of the test medium from penetrating into the material under test and affecting the final test results.
[0038] In one possible implementation, refer to Figure 1 and Figure 2 The molding device 10 includes a first molding body 11 and a second molding body 12. The first molding body 11 and the second molding body 12 are detachably connected together and enclose each other to form a first receiving cavity 101 and a second receiving cavity 102 that are interconnected. There are two second receiving cavities 102 and they are symmetrically distributed on opposite sides of the first receiving cavity 101.
[0039] An inlet 103 is provided on the first molded body 11 or the second molded body 12. The inlet 103 is connected to the first receiving cavity 101 and is used to inject liquid test material into the first receiving cavity 101.
[0040] The second receiving cavity 102 is used to receive the electrical terminal of the electrode 20. The discharge terminal of the electrode 20 extends into the first receiving cavity 101. The test material in the first receiving cavity 101 is solidified and surrounds and connects to the discharge terminal of the electrode 20.
[0041] Based on the above technical solution, since there are two second receiving cavities 102 symmetrically distributed on opposite sides of the first receiving cavity 101, the receiving end of the electrode 20 is housed in the second receiving cavity 102, and the discharge end extends into the first receiving cavity 101. Therefore, the solid test material obtained by casting is the test sample 30, and electrodes 20 are inserted on opposite sides of the test sample 30, that is, two electrodes 20 are distributed on opposite sides of the solid test material. Furthermore, since the first molding body 11 and the second molding body 12 are detachably connected, after the test material has solidified, the solidified test material and the electrodes 20 can be removed together. The shape of the two after the electrodes 20 are inserted into the test sample 30 can be referenced... Figure 4 and Figure 5 .
[0042] It should be understood that the test material in this application may be in a liquid state when heated and turn into a solid state after cooling to room temperature.
[0043] In one specific implementation, reference is made to... Figure 2 The first molded body 11 includes a first groove 111 and a second groove 112 that are interconnected. The depth of the first groove 111 is greater than the depth of the second groove 112. There are two second grooves 112, which are symmetrically distributed on opposite sides of the first groove 111.
[0044] The second molded body 12 includes a third groove and a fourth groove that are interconnected. The depth of the third groove is greater than the depth of the fourth groove. There are two fourth grooves, which are symmetrically distributed on opposite sides of the fourth groove.
[0045] When the first molded body 11 and the second molded body 12 are connected together, the first groove 111 and the third groove are correspondingly enclosed to form the first receiving cavity 101, and the second groove 112 and the fourth groove are correspondingly enclosed to form the second receiving cavity 102.
[0046] The inlet 103 is provided on the first molded body 11 and communicates with the first groove 111, or the inlet 103 is provided on the second molded body 12 and communicates with the second groove 112;
[0047] The third groove and the first groove 111 have the same shape and size, and the fourth groove and the second groove 112 have the same shape and size.
[0048] Obviously, with the above configuration, half of the solid test material is located in the first groove 111 and the other half is located in the third groove. Similarly, half of the electrode 20 is located in the second groove 112 and the other half is located in the fourth groove. In this way, after the first molded body 11 and the second molded body 12 are separated, it is convenient to remove the solid test material and the electrode 20.
[0049] The inner surfaces of the first groove 111 and the second groove 112 are both arc-shaped, and the second groove 112 and the electrode 20 are shaped to match. Thus, the obtained fixed test material has an arc-shaped outer peripheral surface, and the electrode 20 also has an arc-shaped outer peripheral surface. The outer peripheral surface of the electrode 20 has no sharp corners, thereby avoiding the sharp point effect and improving test safety.
[0050] In one example, reference Figure 1 and Figure 2 The first groove 111 and the second groove 112 are both semi-cylindrical, and the second groove 112 matches the shape of the electrode 20.
[0051] In one possible embodiment, the central axis corresponding to the semi-cylindrical inner wall of the first groove 111 coincides with the central axis corresponding to the semi-cylindrical inner wall of the second groove 112. Based on this technical solution, both the electrode 20 and the solid test material are cylindrical structures and coaxially arranged. Therefore, the thickness of the portion of the solid test material surrounding the electrode 20 is uniform throughout, thus forming a uniform insulating environment around the electrode 20. This facilitates the formation of a stable insulating environment around the portion of the solid test material located between the discharge ends of the two electrodes 20, improving the accuracy of the test results.
[0052] Specifically, the difference between the depth of the first groove 111 and the depth of the second groove 112 is greater than or equal to 5 mm and less than or equal to 15 mm; the difference between the depth of the third groove and the depth of the fourth groove is greater than or equal to 5 mm and less than or equal to 15 mm. This setting allows the thickness of the electrode 20 encapsulating the solid test material to be between 5 mm and 15 mm, thus providing a reliable insulating environment and improving the accuracy of the test results. If the thickness of the electrode 20 encapsulating the solid test material is too large, the process requirements become too stringent, making it difficult to form a compliant test sample 30. For example, if the test material is silicone, an excessively thick electrode 20 can easily lead to air bubbles forming inside the solid test material, especially in the area between the discharge ends of the two electrodes 20, resulting in the final test sample 30 failing to meet the test requirements.
[0053] In one possible embodiment, two second receiving cavities 102 are symmetrically distributed on opposite sides of the first receiving cavity 101. Therefore, identical electrodes 20 can be inserted on opposite sides of the solid test material, and it is easy to ensure that the portions of the electrodes 20 outside the solid test material have the same length. This is advantageous because it reduces the number of electrode types and facilitates control over the predetermined test thickness of the portion of the test material located between the discharge ends of the two electrodes 20.
[0054] In one example, in the distribution direction of the first receiving cavity 101 and the second receiving cavity 102, the length of the second receiving cavity 102 is 50 mm. Since the second receiving cavity 102 is used to accommodate a portion of the electrode 20, the length of the portion of the electrode 20 located outside the solid test material can be 50 mm. This facilitates the connection between the electrode 20 and the voltage supply device 40, making it convenient for the electrode 20 to be connected to the voltage supply device 40 used for withstand voltage breakdown testing.
[0055] In one possible embodiment, reference Figures 3 to 5 Electrode 20 includes an outer peripheral surface surrounding its own discharge center line, and a first end face 21 and a second end face located at opposite ends of the outer peripheral surface. The outer peripheral surface is a cylindrical surface. The first end face 21 is located inside the sample 30 to be tested, and the second end face is located outside the sample 30 to be tested. At least the first end face 21 is a spherical surface, and the outer peripheral surface and the first end face 21 of electrode 20 are smoothly connected. In this way, at least the part of the surface of electrode 20 located in the sample 30 to be tested has no sharp corners, thereby avoiding the sharp point effect and improving the safety of the test.
[0056] The second end face can be a spherical surface that smoothly transitions and connects with the outer peripheral surface, or it can be a surface of other shapes; this application does not limit this.
[0057] Based on the aforementioned withstand voltage breakdown test equipment, this application also provides a withstand voltage breakdown test method, which specifically includes:
[0058] Provides 30 samples to be tested and a forming device 10.
[0059] The two electrodes 20 are respectively placed in the two second receiving cavities 102 of the molding device 10.
[0060] High-temperature liquid test material is injected into the first receiving cavity 101 and cooled to room temperature to obtain solid test sample 30;
[0061] The sample 30 and the electrode 20 are removed together from the forming device 10;
[0062] The positive voltage output terminal and negative voltage output terminal of the voltage supply device 40 are electrically connected to the two electrodes 20 respectively;
[0063] The voltage supply device 40 provides the test voltage, and the voltage detector 50 is turned on to perform a withstand voltage breakdown test.
[0064] This method allows for a stable connection between electrode 20 and the sample 30 under test, ensuring a stable distance between the discharge ends of the two electrodes 20 during the test, which helps guarantee the accuracy of the test results.
[0065] It should be noted that, depending on the implementation needs, the various components / steps described in the embodiments of this utility model can be broken down into more components / steps, or two or more components / steps or parts of the operation of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of this utility model.
[0066] The above embodiments are only used to illustrate the present utility model, and are not intended to limit the present utility model. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present utility model. Therefore, all equivalent technical solutions also fall within the scope of the present utility model. The patent protection scope of the present utility model should be defined by the claims.
Claims
1. A withstand voltage breakdown test device, characterized in that, The testing equipment includes: A molding device (10) is used to prepare a sample (30) to be tested. Electrode (20), the electrode (20) includes opposite receiving end and discharge end. When the sample to be tested (30) is made using the forming device (10), the discharge end of the electrode (20) is used to be inserted into the sample to be tested through the forming device (10). There are two electrodes (20), which are located on opposite sides of the sample to be tested (30) respectively. The discharge ends of the two electrodes (20) are distributed at intervals along the extension direction of the electrode (20), and there is a distance L between the discharge ends of the two electrodes. A voltage providing device (40) includes a positive voltage output terminal and a negative voltage output terminal. The positive voltage output terminal is connected to the terminal of one of the electrodes, and the negative voltage output terminal is connected to the terminal of the other electrode. The voltage providing device is used to provide different test voltages according to a preset time interval. A voltage detector (50) is connected to the terminals of the two electrodes (20) and is used to detect the real-time voltage value between the terminals of the two electrodes (20), thereby determining whether the sample under test has passed the withstand voltage breakdown test based on the real-time voltage value, the spacing L, and the test voltage provided by the voltage providing device.
2. The withstand voltage breakdown test equipment according to claim 1, characterized in that, The molding device (10) includes a first molding body (11) and a second molding body (12). The first molding body (11) and the second molding body (12) are detachably connected together and enclose a first receiving cavity (101) and a second receiving cavity (102) that are interconnected. There are two second receiving cavities (102) and they are distributed on opposite sides of the first receiving cavity (101). An inlet (103) is provided on the first molded body (11) or the second molded body (12), and the inlet (103) is connected to the first receiving cavity (101) for injecting liquid test material into the first receiving cavity (101); The second receiving cavity (102) is used to receive the electrical terminal of the electrode (20), the discharge terminal of the electrode (20) extends into the first receiving cavity (101), and the test material in the first receiving cavity (101) is solidified and surrounds and connects to the discharge terminal of the electrode (20).
3. The withstand voltage breakdown test equipment according to claim 2, characterized in that, The first molded body (11) includes a first groove (111) and a second groove (112) that are interconnected. The depth of the first groove (111) is greater than the depth of the second groove (112). There are two second grooves (112) and they are distributed on opposite sides of the first groove (111). The second molded body (12) includes a third groove and a fourth groove that are interconnected. The depth of the third groove is greater than the depth of the fourth groove. There are two fourth grooves, which are distributed on opposite sides of the fourth groove. When the first molded body (11) and the second molded body (12) are connected together, the first groove (111) and the third groove are respectively enclosed to form the first receiving cavity (101), and the second groove (112) and the fourth groove are respectively enclosed to form the second receiving cavity (102). The inlet (103) is disposed on the first molded body (11) and communicates with the first groove (111), or the inlet (103) is disposed on the second molded body (12) and communicates with the second groove (112); The third groove and the first groove (111) have the same shape and size, and the fourth groove and the second groove (112) have the same shape and size.
4. The withstand voltage breakdown test equipment according to claim 3, characterized in that, The inner surface of the first groove (111) and the inner surface of the second groove (112) are both arc-shaped surfaces, and the second groove (112) and the electrode (20) are shaped to match.
5. The withstand voltage breakdown test equipment according to claim 4, characterized in that, Both the first groove (111) and the second groove (112) are semi-cylindrical grooves.
6. The withstand voltage breakdown test equipment according to claim 5, characterized in that, The central axis corresponding to the semi-cylindrical inner wall of the first groove (111) coincides with the central axis corresponding to the semi-cylindrical inner wall of the second groove (112).
7. The withstand voltage breakdown test equipment according to claim 5, characterized in that, The difference between the groove depth of the first groove (111) and the groove depth of the second groove (112) is greater than or equal to 5 mm and less than or equal to 15 mm. The difference between the depth of the third groove and the depth of the fourth groove is greater than or equal to 5 mm and less than or equal to 15 mm.
8. The withstand voltage breakdown test equipment according to claim 2, characterized in that, Two second receiving cavities (102) are symmetrically distributed on opposite sides of the first receiving cavity (101).
9. The withstand voltage breakdown test equipment according to claim 8, characterized in that, In the distribution direction of the first receiving cavity (101) and the second receiving cavity (102), the length of the second receiving cavity (102) is 50 mm.
10. The withstand voltage breakdown test equipment according to claim 1, characterized in that, The electrode (20) includes an outer peripheral surface surrounding its own discharge center line, and a first end face (21) and a second end face located at opposite ends of the outer peripheral surface. The outer peripheral surface is a cylindrical surface. The first end face (21) is located in the sample to be tested (30), and the second end face is located outside the sample to be tested (30). At least the first end face (21) is a spherical surface. The outer peripheral surface of the electrode (20) and the first end face (21) are smoothly connected.