An electrical-thermal aging test device and method based on a scaled-down pot-type insulator

Abstract

This invention discloses an electrothermal aging test apparatus and method based on a scaled-down basin insulator, relating to the field of basin insulator aging testing. The apparatus includes a fixture body and a multi-field coupling simulation system. The fixture body comprises at least one scaled-down basin insulator specimen, a conductive rod, at least one first gas chamber, and at least one second gas chamber. The conductive rod passes through the center of the specimen and is sealed. The first and second gas chambers are respectively located on both sides of the specimen. The multi-field coupling simulation system applies a coupled aging stress field to the specimen, including high-voltage, temperature, and mechanical force simulation units. The high-voltage unit is electrically connected to the conductive rod to establish a high-voltage electric field; the temperature unit provides a controllable temperature for the test space; and the mechanical force unit injects insulating gas into the gas chambers to create a pressure difference, subjecting the specimen to static mechanical loads. This invention has a simple structure, is easy to use, ensures that the aging process matches the operating conditions, and improves the accuracy of life prediction and aging degree evaluation.

Description

Technical Field

[0001] This invention relates to the field of aging test technology for basin insulators, and in particular to an electrothermal aging test device and method based on scaled-down basin insulators. Background Technology

[0002] Pot-type insulators play an indispensable role in GIS equipment, undertaking key functions such as electrical and gas chamber isolation, as well as mechanical support. Their insulation reliability is crucial for the safe and stable operation of GIS. However, as the service life of GIS continues to increase, the failure probability of pot-type insulators also gradually rises. Therefore, accurately assessing the long-term aging characteristics of pot-type insulators and determining their remaining service life accordingly has become a critical issue that urgently needs to be addressed in this field.

[0003] Currently, the assessment of the long-term aging characteristics of basin insulators mainly employs a combination of accelerated electrothermal aging tests and post-aging performance tests. However, this method has significant limitations. On the one hand, in addition to electrical and thermal factors, basin insulators also experience considerable mechanical stress during actual operation, but there is currently a lack of aging test devices and methods capable of simulating the combined effects of electrothermal forces. On the other hand, most current research is based on accelerated aging tests using basin insulator samples (such as circular, dumbbell-shaped, and strip-shaped samples). While this method has the advantages of short aging time and simple operation, the operating conditions of the samples differ from the actual operating conditions of basin insulators, affecting the accuracy of the aging assessment results.

[0004] In summary, existing technologies for accelerated aging tests of basin insulators suffer from problems such as inconsistency with actual working conditions, low accuracy of life prediction models, and inaccurate evaluation of aging degree. There is an urgent need for a more effective testing device and method. Summary of the Invention

[0005] The purpose of this invention is to provide an electrothermal aging test device and method based on a scaled-down basin insulator, so as to solve the problems existing in the prior art. It has a simple structure, is easy to use, effectively ensures that the accelerated aging process of the basin insulator does not match the actual working conditions, effectively improves the accuracy of the life prediction model, and effectively improves the accuracy of the aging degree evaluation.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides an electrothermal aging test device based on a scaled-down basin insulator, comprising: a fixture body and a multi-field coupling simulation system. The fixture body includes at least one scaled-down basin insulator specimen, a conductive rod, at least one first air chamber and at least one second air chamber. The conductive rod passes through the center of the scaled-down basin insulator specimen and is sealed to the scaled-down basin insulator. The first air chamber and the second air chamber are respectively sealed on both sides of the scaled-down basin insulator specimen. The multi-field coupling simulation system is used to apply a coupled aging stress field to the scaled-down basin insulator specimen in the fixture body. The multi-field coupling simulation system includes a high-voltage simulation unit, a temperature simulation unit, and a mechanical force simulation unit. The high-voltage simulation unit is used to be electrically connected to the conductive rod to establish a controllable high-voltage electric field on the scaled-down basin insulator specimen. The temperature simulation unit is used to provide a controllable temperature environment for the test space containing the fixture body. The mechanical force simulation unit is used to inject insulating gas into the first gas chamber and / or the second gas chamber to form a gas pressure difference on both sides of the scaled-down basin insulator specimen, so that the scaled-down basin insulator specimen can withstand a controllable static mechanical load.

[0007] Preferably, the tooling body further includes end-scaled basin insulators and connecting bolts. First connecting flanges are provided at both ends of the first air chamber, and second connecting flanges are provided at both ends of the second air chamber. The connecting bolts are used to pass through the first connecting flanges, the scaled basin insulator specimens, and the second connecting flanges to seal and connect the first air chamber, the scaled basin insulator specimens, and the second air chamber. There are multiple scaled basin insulator specimens, spaced apart along the axial direction of the conductive rod. The end-scaled basin insulator is located at the end of the conductive rod used for electrical connection with the high-voltage simulation unit and seals adjacent first or second air chambers. The first or second air chamber located at the end of the tooling body away from the end-scaled basin insulator has an end-sealing structure.

[0008] Preferably, the openings of adjacent scaled-down basin insulator specimens face opposite directions.

[0009] Preferably, it further includes a first inlet / outlet pipe, a first valve, a second inlet / outlet pipe, and a second valve. The first inlet / outlet pipe is connected to and communicates with the first gas chamber, and the other end is used to be detachably connected to and communicate with an insulating gas source. The first valve is disposed on the first inlet / outlet pipe. The second inlet / outlet pipe is connected to and communicates with the second gas chamber, and the other end is used to be detachably connected to and communicate with the insulating gas source. The second valve is disposed on the second inlet / outlet pipe. The insulating gas is SF6 gas.

[0010] Preferably, the scaled-down basin insulator specimen is a model obtained by scaling down the geometry and materials of a real basin insulator based on the target voltage level, and the maximum outer diameter of the scaled-down basin insulator specimen is no more than 120 mm.

[0011] Preferably, the mechanical force simulation unit further includes a connecting structure load application unit. The scaled-down basin insulator specimen, the first air chamber, and the second air chamber are sealed together by connecting bolts. The connecting structure load application unit is used to apply a preload to the connecting bolts to apply mechanical stress to the scaled-down basin insulator specimen.

[0012] Preferably, the load application unit of the connection structure includes a torque application device and a force sensor, wherein the force sensor is used to monitor the preload applied to the connection bolt.

[0013] Preferably, the temperature simulation unit includes a temperature-controlled heating chamber, and the test space is provided inside the temperature-controlled heating chamber.

[0014] Preferably, the high-voltage simulation unit includes an AC high-voltage generator, the output of which is electrically connected to the conductive rod.

[0015] The present invention also provides a method for using the electrothermal aging test apparatus based on a scaled-down basin insulator as described in any of the preceding claims, comprising the following steps: S1: Assemble the scaled-down basin insulator specimen, conductive rod, first air chamber and second air chamber according to the preset assembly relationship to form the tooling body, ensure the sealed fit between the conductive rod and the center of the scaled-down basin insulator specimen, and seal the first air chamber and second air chamber on both sides of the scaled-down basin insulator specimen respectively. S2: Activate the mechanical force simulation unit to inject SF6 insulating gas into the first and / or second gas chambers, so that a set gas pressure is formed on both sides of the scaled-down basin insulator specimen, thereby allowing the scaled-down basin insulator specimen to bear a controllable static mechanical load. The gas pressure value is adjusted and maintained stably according to the test requirements. S3: Place the fixture body in the test space that contains the fixture body, connect the output terminal of the AC high voltage generator of the high voltage simulation unit to the conductive rod, start the high voltage simulation unit, and establish a controllable high voltage electric field on the scaled-down basin insulator specimen. The voltage level, application method and other parameters of the high voltage electric field are set according to the test plan. S4: Turn on the temperature simulation unit to raise the temperature in the test space to the target temperature according to the set program and keep it constant, providing a controllable temperature environment for the scaled-down pot insulator specimen. S5: After the temperature environment and gas pressure stabilize, the high-voltage simulation unit, temperature simulation unit and mechanical force simulation unit work together to apply a coupled high-voltage electric field, temperature field and mechanical force field to the scaled-down basin insulator specimen and conduct an electrothermal aging test for a preset time; during the test, the stability of each field parameter and the state change of the scaled-down basin insulator specimen are monitored in real time. S7: After the test reaches the preset duration, turn off the high voltage simulation unit, temperature simulation unit and mechanical force simulation unit. After the fixture body cools to room temperature and the pressure in the gas chamber is released to a safe range, take out the fixture body and carry out subsequent performance testing and analysis on the scaled-down pot insulator specimen.

[0016] The present invention achieves the following technical effects compared to the prior art: This invention provides an electrothermal aging test apparatus and method based on a scaled-down basin insulator. By using a scaled-down basin insulator specimen, while maintaining similarity to the geometry, material properties, and stress state of a real basin insulator, the overall size and cost of the test apparatus are significantly reduced, making the test process easier to implement and control in a laboratory environment. The structural design of the fixture body, especially the sealed connection between the conductive rod and the scaled-down basin insulator specimen, and the sealed arrangement of the gas chamber on both sides of the specimen, provides the basic structure for applying various stresses. Furthermore, the multi-field coupling simulation system is subdivided into various units, clarifying the specific function of each unit. The high-voltage simulation unit establishes a controllable high-voltage electric field by connecting to the conductive rod, simulating the electrical environment in actual operation; the temperature simulation unit provides a controllable temperature environment, simulating the thermal environment; the mechanical force simulation unit uses insulating gas injected into the gas chamber to create a pressure difference, subjecting the specimen to a controllable static mechanical load, simulating the mechanical environment. This multi-unit collaborative working method highly replicates the electrothermal multi-field coupling conditions of a basin insulator in actual operation, improving the accuracy and reliability of the aging test. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the electrothermal aging test device based on a scaled-down basin insulator provided by the present invention. Figure 2 This is a schematic diagram of the tooling body in the electrothermal aging test device based on a scaled-down basin insulator provided by the present invention. Figure 3A cross-sectional view of the tooling body in the electrothermal aging test device based on a scaled-down basin insulator provided by the present invention. In the figure: 1. Tooling body; 11. Conductive rod; 12. Scaled-down basin insulator specimen; 13. First air chamber; 14. Second air chamber; 15. End scaled-down basin insulator; 16. First inlet and outlet air pipe; 17. First valve; 18. Second inlet and outlet air pipe; 19. Second valve; 2. Temperature-controlled heating box; 21. Test space. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide an electrothermal aging test device and method based on a scaled-down basin insulator, so as to solve the problems existing in the prior art. It has a simple structure, is easy to use, effectively ensures that the accelerated aging process of the basin insulator does not match the actual working conditions, effectively improves the accuracy of the life prediction model, and effectively improves the accuracy of the aging degree evaluation.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1 This invention provides an electrothermal aging test device based on a scaled-down basin insulator, such as... Figures 1-3 As shown, the device includes: a fixture body 1 and a multi-field coupling simulation system. The fixture body 1 includes at least one scaled-down basin-type insulator specimen 12, a conductive rod 11, at least one first air chamber 13, and at least one second air chamber 14. The conductive rod 11 passes through the center of the scaled-down basin-type insulator specimen 12 and is sealed to the scaled-down basin-type insulator. The first air chamber 13 and the second air chamber 14 are respectively sealed on both sides of the scaled-down basin-type insulator specimen 12. The multi-field coupling simulation system is used to apply a coupled aging stress field to the scaled-down basin-type insulator specimen 12 in the fixture body 1. This structural design clarifies the two core components of the device and their functions. The structural design of the fixture body 1, especially the sealed connection between the conductive rod 11 and the scaled-down basin-type insulator specimen 12, and the sealed arrangement of the air chambers on both sides of the specimen, provides the basic structure for the subsequent application of various stresses. The setup of the multi-field coupling simulation system enables the application of a coupled aging stress field to the scaled-down basin insulator specimen 12, thereby simulating the multi-field coupling conditions in actual operation and helping to accurately study the aging characteristics of basin insulators under complex environments.

[0023] The multi-field coupling simulation system includes a high-voltage simulation unit, a temperature simulation unit, and a mechanical force simulation unit. The high-voltage simulation unit is electrically connected to the conductive rod 11 to establish a controllable high-voltage electric field on the scaled-down basin-type insulator specimen 12. The temperature simulation unit provides a controllable temperature environment for the test space 21 that houses the fixture body 1. The mechanical force simulation unit injects insulating gas into the first gas chamber 13 and / or the second gas chamber 14 to create a gas pressure difference on both sides of the scaled-down basin-type insulator specimen 12, allowing the specimen to withstand a controllable static mechanical load. The subdivision of the multi-field coupling simulation system clarifies the specific functions of each unit. The high-voltage simulation unit establishes a controllable high-voltage electric field by connecting to the conductive rod 11, simulating the electrical environment in actual operation; the temperature simulation unit provides a controllable temperature environment, simulating the thermal environment; and the mechanical force simulation unit uses the gas chambers to inject insulating gas to create a pressure difference, allowing the specimen to withstand a controllable static mechanical load, simulating the mechanical environment. This multi-unit collaborative working method highly replicates the electrothermal-mechanical multi-field coupling conditions in the actual operation of basin insulators, improving the accuracy and reliability of aging tests.

[0024] In a preferred embodiment, the tooling body 1 further includes end-scaled basin insulators 15 and connecting bolts. First connecting flanges are provided at both ends of the first air chamber 13, and second connecting flanges are provided at both ends of the second air chamber 14. The connecting bolts are used to pass through the first connecting flanges, the scaled basin insulator specimens 12, and the second connecting flanges to seal and connect the first air chamber 13, the scaled basin insulator specimens 12, and the second air chamber 14. There are multiple scaled basin insulator specimens 12, spaced apart along the axial direction of the conductive rod 11. The end-scaled basin insulators 15 are located at the end of the conductive rod 11 used for electrical connection with the high-voltage simulation unit, and seal adjacent first air chambers 13 or second air chambers 14. The first air chamber 13 or second air chamber 14 located at the end of the tooling body 1 away from the end-scaled basin insulators 15 constitutes an end-sealing structure. The addition of end-scaled basin insulators 15 and connecting bolts improves the structure of the tooling body 1. The connecting bolts mate with the flanges at both ends of the gas chamber, achieving a sealed connection between all components and ensuring the airtightness of the gas chamber. This helps to accurately simulate the gas pressure environment in actual operation. Multiple scaled-down basin-type insulator specimens 12 are spaced apart, allowing for simultaneous aging tests on multiple specimens, improving testing efficiency. Furthermore, the scaled-down basin-type insulators 15 at the ends not only provide a sealing function but also facilitate connection to the high-voltage simulation unit, optimizing the overall structural layout.

[0025] In a preferred embodiment, a sealing ring is provided between the first connecting flange and the scaled-down bowl insulator specimen 12, and a sealing ring is also provided between the second connecting flange and the scaled-down bowl insulator specimen 12.

[0026] In a preferred embodiment, the openings of adjacent scaled-down basin insulator specimens 12 face opposite directions. This design ensures that the forces acting on each scaled-down basin insulator specimen 12 are balanced when subjected to gas pressure differences, effectively reducing the cumulative stress in the axial direction of the entire fixture body 1. This avoids deformation of the fixture body 1 or loosening of connections due to excessive unidirectional stress, significantly improving the structural stability and long-term operational reliability of the fixture body 1 under complex test conditions such as high pressure, high gas pressure, and temperature cycling. Simultaneously, the opposite orientation of the openings also makes the airflow distribution between adjacent chambers more uniform, reducing the adverse effects of local airflow disturbances on the electric field distribution on the insulator surface, further ensuring the consistency between the multi-physics environment experienced by each scaled-down basin insulator specimen 12 and the actual operating conditions.

[0027] In a preferred embodiment, the device further includes a first inlet / outlet pipe 16, a first valve 17, a second inlet / outlet pipe 18, and a second valve 19. The first inlet / outlet pipe 16 is connected to and communicates with the first gas chamber 13, and its other end is detachably connected to and communicates with an insulating gas source. The first valve 17 is disposed on the first inlet / outlet pipe 16. The second inlet / outlet pipe 18 is connected to and communicates with the second gas chamber 14, and its other end is detachably connected to and communicates with an insulating gas source. The second valve 19 is disposed on the second inlet / outlet pipe 18. The insulating gas is SF6 gas. The first inlet / outlet pipe 16, the second inlet / outlet pipe 18, and the corresponding first valve 17 and second valve 19 facilitate the control of the insulating gas (SF6 gas) entering and exiting the gas chamber, enabling precise adjustment of the gas pressure within the chamber, thereby accurately simulating the gas pressure environment experienced by the basin insulator during actual operation. The detachable connection method facilitates maintenance and replacement of the gas source, improving the practicality and flexibility of the device.

[0028] In a preferred embodiment, the scaled-down basin insulator specimen 12 is a model obtained by scaling down the geometry and materials of a real basin insulator based on the target voltage level. The maximum outer diameter of the scaled-down basin insulator specimen 12 is no more than 120 mm. Using a scaled-down basin insulator specimen 12 with a maximum outer diameter of no more than 120 mm ensures the similarity between the specimen and the real basin insulator in terms of geometry and material properties, accurately simulating the aging characteristics of the real insulator. Furthermore, its smaller size facilitates processing and operation, and also helps to accelerate the aging test process and improve test efficiency.

[0029] In a preferred embodiment, the mechanical force simulation unit further includes a connecting structure load application unit. The scaled-down pot-type insulator specimen 12, the first air chamber 13, and the second air chamber 14 are sealed together by connecting bolts. The connecting structure load application unit applies a preload to the connecting bolts to apply mechanical stress to the scaled-down pot-type insulator specimen 12. The addition of the connecting structure load application unit further enriches the functionality of the mechanical force simulation unit. By applying a preload to the connecting bolts, additional mechanical stress is applied to the scaled-down pot-type insulator specimen 12, more comprehensively simulating the complex mechanical force conditions experienced by the pot-type insulator in actual operation, enabling the test to more accurately reflect its aging characteristics.

[0030] In a preferred embodiment, the load application unit for the connecting structure includes a torque application device and a force sensor. The force sensor monitors the preload applied to the connecting bolts. The combination of the torque application device and the force sensor enables precise control and monitoring of the preload of the connecting bolts. By monitoring the preload in real time with the force sensor, the torque application device can be precisely adjusted according to the test requirements, ensuring that the mechanical stress applied to the scaled-down pot insulator specimen 12 is accurate and controllable, improving the reliability and repeatability of the test data. Referring to the standard GB / T30834-2014 "Test Method for Torque-Clamping Force of Bolt Connections", the axial force sensor is placed on the cover plate bolt, and a torque wrench is used to apply force (e.g., a torque of 30 NM corresponds to a force of 10 kN. When tightening the same bolt again, if the torque measured by the torque wrench is 30 NM, it can be considered that the preload is approximately 10 kN).

[0031] In a preferred embodiment, the temperature simulation unit includes a temperature-controlled heating chamber 2, which contains a test space 21. By using the temperature-controlled heating chamber 2 as the temperature simulation unit, the temperature of the test space 21 can be precisely controlled, providing a stable and controllable temperature environment for the scaled-down basin insulator specimen 12. This meets the aging test requirements under different temperature conditions and helps to study the influence of temperature on the aging characteristics of the basin insulator.

[0032] In a preferred embodiment, the high-voltage simulation unit includes an AC high-voltage generator. The output end of the AC high-voltage generator is used to be electrically connected to the conductive rod 11. As the core component of the high-voltage simulation unit, the AC high-voltage generator can provide a controllable AC high voltage to the conductive rod 11, thereby establishing a stable and accurate high-voltage electric field on the scaled-down basin insulator specimen 12, simulating the electrical environment in actual operation, and providing the necessary conditions for studying the aging characteristics of the basin insulator under the action of the electric field.

[0033] Example 2 This embodiment also provides a method for using the electrothermal aging test device based on a scaled-down basin insulator as described in any of Embodiment 1, including the following steps: Experimental preparation phase Operating Condition Survey and Analysis: Through surveys and the use of COMSOL simulation software, detailed operating condition parameters of the 220kV basin insulator in actual operation were obtained, including a temperature of 70℃; an average working field strength of 1.36kV / mm and a maximum working field strength of 6kV / mm; an average mechanical stress of 1.34MPa and a maximum stress of 14MPa. These parameters provide important basis for determining the operating conditions for subsequent accelerated aging tests.

[0034] Determining the accelerated aging test conditions: Based on the actual operating parameters obtained above, the accelerated aging test conditions were initially determined to be a temperature of 90℃ and an electric field strength of 6kV / mm. Considering the mechanical forces experienced by the basin insulator in actual operation, it was decided to apply mechanical forces through a combination of bolts and gas pressure to more realistically simulate actual operating conditions.

[0035] Fabrication of scaled-down basin insulators: Scaled-down basin insulators are fabricated using a casting method according to design requirements. These scaled-down basin insulators are model parts obtained by proportionally scaling down the geometry and materials of a real basin insulator for the target voltage level. The maximum outer diameter is no more than 120mm, ensuring similarity to the real insulator in terms of size and material properties, in order to accurately simulate the aging characteristics of the real insulator.

[0036] Electric field simulation calculation: For the prepared scaled-down basin insulator and tooling structure, the electric field distribution under the design conditions is calculated using simulation software, thereby determining the specific voltage value to be applied under an electric field strength of 6kV / mm, providing accurate electrical parameters for subsequent tests.

[0037] Equipment setup and installation phase Tooling body 1 assembly: At least one scaled-down bowl insulator specimen 12 is passed through its center by a conductive rod 11, ensuring that the conductive rod 11 and the scaled-down bowl insulator specimen 12 are in a sealed fit.

[0038] The first air chamber 13 and the second air chamber 14 are respectively sealed on both sides of the scaled-down basin insulator specimen 12. If there are multiple scaled-down basin insulator specimens 12, the specimens are spaced apart in the axial direction of the conductive rod 11, and the openings of adjacent scaled-down basin insulator specimens 12 face opposite directions.

[0039] Connecting bolts are used to pass through the first connecting flanges at both ends of the first air chamber 13, the scaled-down basin insulator specimen 12, and the second connecting flanges at both ends of the second air chamber 14 to seal and connect the first air chamber 13, the scaled-down basin insulator specimen 12, and the second air chamber 14. An end scaled-down basin insulator 15 is provided at the end of the conductive rod 11 used for electrical connection with the high-voltage simulation unit to seal the adjacent first air chamber 13 or second air chamber 14. The first air chamber 13 or second air chamber 14 located at the end of the tooling body 1 away from the end scaled-down basin insulator 15 is set as an end sealing structure.

[0040] Connecting multi-field coupled simulation systems: Mechanical force simulation unit connection: The first gas chamber 13 is detachably connected to and communicates with the insulating gas source (SF6 gas) through the first inlet and outlet pipe 16, and a first valve 17 is provided on the first inlet and outlet pipe 16; the second gas chamber 14 is detachably connected to and communicates with the insulating gas source through the second inlet and outlet pipe 18, and a second valve 19 is provided on the second inlet and outlet pipe 18.

[0041] A torque application device and a force sensor are installed at the connecting bolt. The force sensor is used to monitor the preload applied to the connecting bolt, and the torque application device is used to apply a preload load to the connecting bolt, thereby applying mechanical stress to the scaled-down pot insulator specimen 12.

[0042] High-voltage simulation unit connection: Connect the output terminal of the AC high-voltage generator to the conductive rod 11 so as to establish a controllable high-voltage electric field on the scaled-down basin insulator specimen 12.

[0043] Temperature simulation unit setup: Place the assembled tooling body 1 inside the temperature-controlled heating box 2. The temperature-controlled heating box 2 is the temperature simulation unit, which can provide a controllable temperature environment for the tooling body 1.

[0044] Experimental phase Gas filling: Open the first valve 17 and the second valve 19 to fill the tooling interval gas chamber with SF6 gas from the insulating gas source. Fill the first gas chamber 13 with 0.3MPa of SF6 gas to form a gas pressure difference on both sides of the scaled-down basin insulator specimen 12, so that it can withstand a controllable static mechanical load.

[0045] Temperature setting: Set the temperature of the temperature-controlled heating chamber 2 to 90℃ to provide the set temperature environment for the scaled-down basin insulator specimen 12.

[0046] Electric field application: Start the AC high voltage generator and establish a high voltage electric field with a field strength of 6kV / mm on the scaled-down basin insulator specimen 12 according to the voltage value determined by the previous simulation calculation. At this time, the scaled-down basin insulator specimen 12 is in an accelerated aging test environment with electrothermal-mechanical multi-field coupling, and the aging test begins.

[0047] Throughout the experiment, close monitoring was maintained of the preload of the connecting bolts as monitored by the force sensor, the gas pressure in the air chamber as displayed by the pressure gauge, and the temperature of the temperature-controlled heating chamber 2. All parameters were ensured to remain within their set values ​​to guarantee the accuracy and stability of the experiment. After the experiment, the equipment was shut down according to the relevant safety regulations and operating procedures, and the experimental data were collected and analyzed.

[0048] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An electrothermal aging test device based on a scaled-down basin insulator, characterized in that: include: The tooling body includes at least one scaled-down basin insulator specimen, a conductive rod, at least one first air chamber and at least one second air chamber. The conductive rod passes through the center of the scaled-down basin insulator specimen and is sealed to the scaled-down basin insulator. The first air chamber and the second air chamber are respectively sealed on both sides of the scaled-down basin insulator specimen. A multi-field coupling simulation system is used to apply an aging stress field with coupling effect to the scaled-down basin insulator specimen in the tooling body.

2. The electrothermal aging test device based on a scaled-down basin insulator according to claim 1, characterized in that: The tooling body also includes end-scaled basin insulators and connecting bolts. The first air chamber has a first connecting flange at both ends, and the second air chamber has a second connecting flange at both ends. The connecting bolts are used to pass through the first connecting flange, the scaled basin insulator specimen, and the second connecting flange to seal the first air chamber, the scaled basin insulator specimen, and the second air chamber. There are multiple scaled basin insulator specimens, and each scaled basin insulator specimen is spaced apart in the axial direction of the conductive rod. The end-scaled basin insulator is located at the end of the conductive rod used for electrical connection with the high-voltage simulation unit and seals the adjacent first air chamber or second air chamber. The first air chamber or second air chamber located at the end of the tooling body away from the end-scaled basin insulator has an end-sealing structure.

3. The electrothermal aging test device based on a scaled-down basin insulator according to claim 2, characterized in that: The bowl openings of adjacent scaled-down bowl insulator specimens face opposite directions.

4. The electrothermal aging test device based on a scaled-down basin insulator according to claim 3, characterized in that: It also includes a first inlet / outlet pipe, a first valve, a second inlet / outlet pipe, and a second valve. The first inlet / outlet pipe is connected to and communicates with the first gas chamber, and the other end is used to be detachably connected to and communicate with an insulating gas source. The first valve is disposed on the first inlet / outlet pipe. The second inlet / outlet pipe is connected to and communicates with the second gas chamber, and the other end is used to be detachably connected to and communicate with the insulating gas source. The second valve is disposed on the second inlet / outlet pipe. The insulating gas is SF6 gas.

5. The electrothermal aging test device based on a scaled-down basin insulator according to claim 4, characterized in that: The scaled-down basin insulator specimen is a model obtained by scaling down the geometry and materials of a real basin insulator based on the target voltage level. The maximum outer diameter of the scaled-down basin insulator specimen is no more than 120 mm.

6. The electrothermal aging test device based on a scaled-down basin insulator according to claim 1, characterized in that: The multi-field coupled simulation system includes: A high-voltage simulation unit is used to be electrically connected to the conductive rod to establish a controllable high-voltage electric field on the scaled-down basin insulator specimen. A temperature simulation unit is provided to provide a controllable temperature environment for the test space that houses the tooling body. A mechanical force simulation unit is used to inject insulating gas into the first gas chamber and / or the second gas chamber to form a gas pressure difference on both sides of the scaled-down basin insulator specimen, so that the scaled-down basin insulator specimen can withstand a controllable static mechanical load.

7. The electrothermal aging test device based on a scaled-down basin insulator according to claim 6, characterized in that: The mechanical force simulation unit further includes a connection structure load application unit. The scaled-down basin insulator specimen, the first air chamber, and the second air chamber are sealed together by connecting bolts. The connection structure load application unit is used to apply a preload to the connecting bolts to apply mechanical stress to the scaled-down basin insulator specimen.

8. The electrothermal aging test device based on a scaled-down basin insulator according to claim 7, characterized in that: The load application unit of the connection structure includes a torque application device and a force sensor, the force sensor being used to monitor the preload applied to the connection bolt.

9. The electrothermal aging test device based on a scaled-down basin insulator according to claim 8, characterized in that: The temperature simulation unit includes a temperature-controlled heating chamber, and the test space is provided inside the temperature-controlled heating chamber; the high-voltage simulation unit includes an AC high-voltage generator, and the output end of the AC high-voltage generator is used to be electrically connected to the conductive rod.

10. A method of using the electrothermal aging test apparatus based on a scaled-down basin insulator as described in any one of claims 1 to 9, characterized in that: Includes the following steps: S1: Assemble the scaled-down basin insulator specimen, conductive rod, first air chamber and second air chamber according to the preset assembly relationship to form the tooling body, ensure the sealed fit between the conductive rod and the center of the scaled-down basin insulator specimen, and seal the first air chamber and second air chamber on both sides of the scaled-down basin insulator specimen respectively. S2: Activate the mechanical force simulation unit to inject SF6 insulating gas into the first and / or second gas chambers, so that a set gas pressure is formed on both sides of the scaled-down basin insulator specimen, thereby allowing the scaled-down basin insulator specimen to bear a controllable static mechanical load. The gas pressure value is adjusted and maintained stably according to the test requirements. S3: Place the fixture body in the test space that contains the fixture body, connect the output terminal of the AC high voltage generator of the high voltage simulation unit to the conductive rod, start the high voltage simulation unit, and establish a controllable high voltage electric field on the scaled-down basin insulator specimen. The voltage level, application method and other parameters of the high voltage electric field are set according to the test plan. S4: Turn on the temperature simulation unit to raise the temperature in the test space to the target temperature according to the set program and keep it constant, providing a controllable temperature environment for the scaled-down pot insulator specimen. S5: After the temperature environment and gas pressure stabilize, the high voltage simulation unit, temperature simulation unit and mechanical force simulation unit work together to apply the coupled high voltage electric field, temperature field and mechanical force field to the scaled-down basin insulator specimen and carry out an electrothermal aging test for a preset time. During the test, the stability of each field parameter and the state changes of the scaled-down pot insulator specimen were monitored in real time. S7: After the test reaches the preset duration, turn off the high voltage simulation unit, temperature simulation unit and mechanical force simulation unit. After the fixture body cools to room temperature and the pressure in the gas chamber is released to a safe range, take out the fixture body and carry out subsequent performance testing and analysis on the scaled-down pot insulator specimen.

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