Curvature electrode performance testing device and method for cable slice

Abstract

The invention discloses a curvature electrode performance testing device and method for cable slicing, and belongs to the technical field of high-voltage electrical equipment tests.The device comprises a curvature electrode device and a multi-environment simulation cavity, and the curvature electrode device is arranged in the multi-environment simulation cavity; the curvature electrode device comprises a height adjusting screw knob, a high-voltage curvature electrode, a grounding curvature electrode, a temperature control heating device and a supporting frame body; a to-be-tested cable slice is placed between the high-voltage curvature electrode and the grounding curvature electrode for performance test; a height adjusting screw knob is arranged above the high-voltage curvature electrode to adjust the distance between the electrodes, and a temperature control heating device is connected with the grounding curvature electrode to heat the cable slice; the multi-environment simulation cavity is connected with an external high-voltage power supply and provides a simulation test environment. The problems that an existing testing device is poor in attachment and adjustability and lacks multi-physical field coupling and environment simulation capacity can be solved, and the experimental accuracy and reliability of cable slices under complex working conditions are improved.

Description

Technical Field

[0001] The present application relates to the technical field of high-voltage electrical equipment testing, and in particular to a device and method for testing the performance of a curvature electrode for cable slicing. Background Art

[0002] With the continuous deepening of research on high-voltage cable technology and new insulation materials, partial discharge behavior, high-voltage breakdown mechanism, and the influence of multiple physical factors such as temperature, electric field, and pressure on insulation performance have gradually become research hotspots. When conducting relevant experimental research, samples are usually slices prepared from cable busbars or insulation materials. High-voltage loading experiments are required to simulate actual voltage, electric field distribution, and even working environment temperature and stress conditions to explore the evolution of insulation performance, degradation mechanism, and breakdown characteristics. However, existing experimental equipment has limitations to varying degrees in terms of electrode structure, bonding method, temperature control, and stress regulation, making it difficult to meet the test requirements of complex working condition simulation and high repeatability and high stability.

[0003] Currently, mainstream experimental systems mostly use flat-plate or pin-plate electrode structures. A typical example is the power frequency breakdown test device specified in the IEC 60243 standard. Its structure is that two flat-plate electrodes clamp the sample, fixed by mechanical pressure or spiral compression, and the breakdown voltage is measured after high voltage is applied. This structure is suitable for breakdown tests on uniform dielectric layers, but when the experimental object is a cable sample with a certain curvature or a composite structure, the flat electrode cannot fit well with the cable slice, resulting in air gaps between the interfaces, which can easily cause corona discharge and partial discharge interference, affecting the authenticity and repeatability of the experiment, and may even cause premature breakdown. In addition, due to the structural mismatch, it is also impossible to accurately evaluate the actual electrical performance of the cable insulation material under a well-fitted stress state.

[0004] Another structure commonly used in partial discharge experiments is the needle-plate electrode structure, which features a needle-shaped or cone-shaped metal probe on top and a grounded flat plate below to simulate the discharge environment at a tip defect. While this structure is suitable for partial discharge inception voltage testing and defect morphology analysis, the contact area between the needle tip and the specimen is extremely small, stress is concentrated, and the electric field distribution is extremely uneven, making it unsuitable for comprehensive evaluation of the high-voltage performance of complete insulating structures. In particular, it is unable to track discharge behavior in the entire space and conduct multi-point response analysis. Furthermore, traditional needle-plate structures generally lack temperature control and real-time pressure adjustment capabilities, making them incapable of conducting complex operating tests under thermal-electrical-mechanical coupling conditions.

[0005] In recent years, some experimental platforms have also developed a "curvature electrode" system for cable slices, that is, the electrode shape is designed to be an arc with a certain radius, matching the outer contour of the cable slice, thereby improving the fit. Among them, some studies use metal bent plates or arc electrodes fixed on a frame to clamp the cable slices, but the following problems are common: First, the spacing between the electrodes cannot be adjusted, which cannot adapt to the experimental requirements of samples of different thicknesses or loading different mechanical stresses; second, there is a lack of precise adjustment structure at the high-voltage end, which makes it difficult to ensure stable contact between the electrode and the sample and the uniformity of the electric field; third, there is no integrated temperature control unit, which cannot realize high-temperature and high-voltage coupling experiments; fourth, the test chamber is poorly sealed and cannot simulate special environments such as water injection, oil bath or vacuum, which limits the application scenarios of this device in the study of high-voltage insulating materials.

[0006] For example, prior art document CN109991482A discloses a curvature electrode device for detecting space charge in cable insulation. This device uses upper and lower curved electrodes to clamp a partially annular insulation specimen, and a screw adjusts the electrode spacing to accommodate different specifications. However, this device primarily focuses on space charge measurement and lacks temperature control, the ability to simulate diverse environmental conditions, and real-time pressure monitoring and discharge observation capabilities, resulting in significant functional limitations.

[0007] Furthermore, the commonly used electric heating plates for sample heating are typically external modules, separate from the electrode system. This results in uneven sample heating and low heating efficiency. These heating structures are also inconvenient for spatial wiring and electric field control, and do not support real-time temperature feedback and closed-loop regulation. Similarly, research on pressure loading has mostly focused on integrated pressure chambers, such as pneumatic or hydraulic loading platforms, but these are bulky and complex, making them difficult to implement in conventional laboratories.

[0008] Therefore, based on the above analysis, the main problems of the existing technology in structural design can be summarized as follows: Poor electrode fit: Most are flat or needle-plate electrodes that cannot adapt to curvature samples, resulting in large errors in partial discharge testing; Lack of adjustable structure: The electrode spacing is fixed, and different stress loading or thickness adaptation cannot be achieved; Single temperature control: Only a few systems have a heating function, and the heating method is inefficient, making it impossible to create a constant temperature environment; Inability to simulate complex working conditions: Lack of support for chamber environments such as oil baths, water immersion, and vacuuming, resulting in insufficient test flexibility; Difficulty in observation: Some systems do not have transparent windows, which is not conducive to visual tracking and filming of the experimental process. In addition, existing experimental systems generally lack consideration of the coupling effects of multiple physical fields such as electricity, heat, and mechanics, and do not introduce intelligent sensing and closed-loop control technologies to ensure stable and controllable test conditions.

[0009] In summary, existing electrode systems have technical shortcomings in terms of fit, adjustability, environmental simulation capabilities, and visual observation, which seriously restrict the precision, standardization, and development of multi-parameter coupling tests for insulation performance testing. Therefore, it is necessary to develop a new high-voltage experimental electrode system with a reasonable structure, high functional integration, and strong adaptability to improve the simulation capabilities of actual working conditions and meet the needs of researchers for in-depth research on the evolution of electrical performance under the combined effects of temperature, electric field, and pressure. Summary of the Invention

[0010] In order to address the deficiencies in the prior art, the present invention provides a curvature electrode high-voltage experimental device with good fit, multi-dimensionally adjustable structure, temperature control, intelligent closed-loop control and pressure monitoring functions, which solves the problems of poor fit, poor adjustability, lack of multi-physical field coupling and environmental simulation capabilities of existing devices, and improves the experimental accuracy and reliability of cable slicing under complex working conditions.

[0011] The present invention adopts the following technical solutions.

[0012] A first aspect of the present invention discloses a curvature electrode performance testing device for cable slicing, comprising: a curvature electrode device and a multi-environment simulation cavity, wherein the curvature electrode device is disposed inside the multi-environment simulation cavity; The curvature electrode device includes: a height adjustment screw knob, a high-voltage curvature electrode, a grounded curvature electrode, a temperature control heating device and a support frame; The high-voltage curvature electrode and the ground curvature electrode are arranged relative to each other and are both located inside the support frame. The cable slice to be tested is placed between the high-voltage curvature electrode and the ground curvature electrode for performance testing. A height adjustment screw knob is provided above the high-voltage curvature electrode for adjusting the distance between the high-voltage curvature electrode and the ground curvature electrode and fixing the cable slice to be tested. The temperature control heating device is connected to the ground curvature electrode for heating the cable slice. The curvature electrode device further includes: a real-time pressure detection device, which is provided between the contact surface of the high-voltage curvature electrode and the cable slice to be tested and is used to detect the force applied to the cable slice to be tested. The multi-environment simulation chamber is connected to an external high-voltage power supply and provides a simulated test environment.

[0013] Preferably, the high-voltage curvature electrode is a fan-shaped structure, the grounding curvature electrode is an arc-shaped metal structure, and the cable slice to be tested is placed in the middle to form an electrode clamping space.

[0014] Preferably, the central angle of the high-voltage curvature electrode and the grounding curvature electrode is the same, and the central angle is 20-30°.

[0015] Preferably, the support frame comprises: a ground base, an upper support plate and an insulating support column; The height adjustment screw knob is threadedly connected to the upper support plate, and the position of the high-voltage curvature electrode is adjusted by rotating the height adjustment screw knob. The grounding curvature electrode is installed on the grounding base, and the upper support plate is connected to the grounding base through an insulating support column.

[0016] Preferably, the high-voltage curvature electrode and the ground curvature electrode adopt a detachable modular installation structure, and motor components with different curvature radii or sizes can be replaced to adapt to cable slice samples of different specifications.

[0017] Preferably, the temperature control heating device is installed inside or at the bottom of the grounded curvature electrode, and is connected through an external temperature control interface for power supply and temperature regulation, thereby achieving indirect heating of the cable slice to be tested.

[0018] Preferably, the grounded curvature electrode is connected to the ground wire through a grounding lead, the grounding lead passes through the sealed lead hole of the multi-environment simulation cavity, and the interface is fixed with a sealing nut to prevent pressure release and insulation breakdown.

[0019] Preferably, the multi-environment simulation chamber comprises: a high-pressure end lead wire, an upper valve, an upper channel, a lower valve and a lower channel; One end of the high-voltage lead-out wire is fixedly connected to the high-voltage curvature electrode, and the other end passes through the multi-environment simulation cavity and is connected to an external high-voltage power supply; the upper valve and the upper channel, and the lower valve and the lower channel cooperate to form a port that can be opened and closed at will, which is used to realize different simulation environments.

[0020] Preferably, the multi-environment simulation chamber further comprises: a flange observation window, which is arranged on the outer wall of the multi-environment simulation chamber and is used to observe the cable slices and discharge status under sealed conditions.

[0021] A second aspect of the present invention discloses a method for testing the performance of a curvature electrode for cable slicing, wherein the method comprises the following steps: Prepare the cable slice sample to be tested and place it between the high voltage curvature electrode and the ground curvature electrode; Rotate the height adjustment screw knob to adjust the position of the high-voltage curvature electrode. When the pressure between the high-voltage curvature electrode and the cable slice to be tested reaches the test standard, stop adjusting and fix the height adjustment screw knob; Start the temperature control heating device to raise the temperature to the test set value, generate a simulated test environment for the multi-environment simulation cavity and keep it sealed; Start the high voltage power supply for testing, observe the status of the cable slice to be tested and record the relevant data to complete the test.

[0022] Compared with the prior art, the beneficial effects of the present invention include at least: (1) The present invention innovatively adopts an arc-shaped electrode structure that is highly compatible with the geometric curvature of the cable slice, enabling full structural contact between the electrode and the cable sample, thus avoiding the local air gap, electric field distortion, and premature discharge breakdown caused by uneven contact of traditional flat electrodes. This structure is particularly suitable for cable samples with a cylindrical shape, making the discharge path more realistic and controllable, and the electric field distribution more uniform, greatly improving the reliability and representativeness of the experimental data. At the same time, by optimizing the edge shape and coverage of the electrode, the uniformity of the electric field distribution is improved, avoiding local discharge caused by excessive edge field strength.

[0023] (2) The electrode structure introduces an adjustable spiral knob mechanism and a multi-dimensional precision adjustment component, which can achieve fine adjustment of the distance between the upper and lower electrodes and precise positioning in multiple degrees of freedom, adapt to samples of different thicknesses and shapes, and load specific stress conditions as needed. This adjustment structure not only has high mechanical precision, but also can maintain the stability of the set distance through the locking mechanism, ensuring that the force does not deform or deflect during the experiment. In conjunction with the pressure sensor set inside the electrode or on the contact surface, the contact pressure applied to the sample surface can be monitored in real time, achieving effective control of the electric-mechanical synergistic experimental conditions, which is a key means to study the local discharge, breakdown, and aging behavior of electrical insulating materials under pressure. The robust structural design also enables the device to adapt to nonlinear load shocks such as local discharge and breakdown, ensuring the safety and stability of the experimental process.

[0024] (3) A metal heating wire is innovatively embedded inside the lower electrode to form a three-dimensional composite heating structure. Through intelligent closed-loop control of the external temperature control system, the sample can be heated at a constant temperature within the set temperature range, creating a thermally stable experimental environment. This structure overcomes the problems of low thermal efficiency and uneven temperature distribution of traditional external heating methods, can respond quickly and accurately maintain the set temperature, and is suitable for studying the conductive behavior, breakdown strength evolution, and thermal aging laws of cable insulation materials in high-temperature environments, and has good application prospects.

[0025] (4) To meet the needs of experiments under complex media and environmental conditions, the present invention sets up a closed experimental chamber outside the electrode device and is equipped with two nozzles with switch valves. Insulating oil, water, or other liquid media can be injected according to the experimental requirements. Low-pressure environment simulation can also be achieved through the vacuum system, thereby supporting insulation performance testing under various conditions such as oil bath, water injection, and airtightness. This structure greatly expands the scope of experimental application and provides an operational platform for simulating actual operating conditions such as water tree aging, oil immersion overheating, high-humidity and high-temperature aging, and low-pressure vacuum breakdown.

[0026] (5) A transparent flange observation window is provided on the side of the device, which facilitates real-time observation of visible physical changes such as discharge phenomena, bubble formation, and crack propagation on the sample surface without destroying the test seal, providing interface support for the subsequent integration of high-frame-rate cameras or laser diagnostic systems. The design of this observation window not only improves the controllability and safety of the experiment, but also facilitates the visual tracking and data recording of discharge behavior and breakdown paths.

[0027] (6) The electrode assembly of the present invention adopts a modular design. The high-voltage curvature electrode and the ground curvature electrode are fixed by a detachable connection. Electrode heads with different curvature radii or sizes can be replaced according to test needs, thereby adapting to cable slice specimens of different specifications and facilitating the maintenance and upgrading of each component, further improving the scope of application and service life of the device.

[0028] In summary, the present invention has made comprehensive innovations in structural matching, adjustment flexibility, modular integration, intelligent control, temperature control accuracy, environmental simulation capability, and experimental visualization. It can be widely applied to the research on partial discharge, breakdown, and durability of samples such as cable slices, polymer insulation materials, and dielectric interface structures, and has high practicality and engineering promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural diagram of the curvature electrode device of the present invention; Figure 2 is a schematic diagram of clamping the curvature electrode device of the present invention; Figure 3 is a structural diagram of the multi-environment simulation chamber of the present invention; Figure 4 is a flow chart of the testing method of the present invention; In the figure: 1. Height adjustment screw knob; 2. Real-time pressure detection device; 3. High-voltage curvature electrode; 4. Ground curvature electrode; 5. Ground base; 6. Upper support plate; 7. Insulating support column; 8. Temperature control heating device; 9. High-voltage end lead wire; 10. Upper valve; 11. Upper channel; 12. Flange observation window; 13. Lower valve; 14. Lower channel; 15. Multi-environment simulation chamber. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] like Figure 1-3 As shown, embodiment 1 of the present invention discloses a curvature electrode performance test device for cable slicing, the test device comprising: a curvature electrode device and a multi-environment simulation cavity 15, wherein the curvature electrode device is disposed inside the multi-environment simulation cavity 15; The curvature electrode device includes: a height adjustment screw knob 1, a high-voltage curvature electrode 3, a ground curvature electrode 4, a support frame, and a temperature control heating device 8; The high-voltage curvature electrode 3 and the ground curvature electrode 4 are arranged opposite each other and are both located in the support frame. The cable slice is placed between the high-voltage curvature electrode 3 and the ground curvature electrode 4. A height adjustment screw knob 1 is provided above the high-voltage curvature electrode 3 to adjust the distance from the ground curvature electrode 4 to adapt to the thickness of the cable slice. The real-time pressure detection device 2 is provided on the high-voltage curvature electrode 3 to detect the force applied to the cable slice. The temperature control and heating device 8 is connected to the ground curvature electrode 4 to heat the cable slice and ensure reliable and stable operation of the temperature control device. The high-voltage curvature electrode 3 and the ground curvature electrode 4 are both fixed to the support frame through a detachable connection. Electrode assemblies of different curvatures can be replaced according to the sample size to improve applicability.

[0032] In a preferred but non-limiting embodiment of the present invention, the high-voltage curvature electrode 3 is a fan-shaped structure, and the grounding curvature electrode 4 is an arc-shaped metal structure. The outer arc surface of the high-voltage curvature electrode 3 matches the inner arc surface structure of the cable slice to be tested, and the inner arc surface of the grounding curvature electrode 4 matches the outer arc surface structure of the cable slice to be tested. They are arranged relative to each other along the arc direction to form an electrode clamping space.

[0033] The central angle of the fan-shaped structure and the arc-shaped metal structure is 20-30°, which can be adjusted according to the curvature of the cable slice to be tested, and is generally preferably 25°.

[0034] More preferably, Figure 2 As shown, the cable slice is placed between the high-voltage curvature electrode 3 and the grounded curvature electrode 4, and the high-voltage curvature electrode 3 adjusts the contact downward and applies pressure to ensure that the electrode is completely in contact with the arc surface of the sample.

[0035] It is worth noting that the cable slices must not be placed beyond the electrode range to prevent discharge phenomena such as flashover, that is, when placing the cable slices, it must be ensured that their main power receiving area is completely located between the high-voltage curvature electrode 3 and the grounding curvature electrode 4. The exposed parts on both sides of the cable slices can be placed in the electrode guide groove to avoid sliding. The exposed parts refer to the parts of the edge of the cable slice that are not involved in power reception and can be appropriately extended into the electrode guide groove to play a limiting and anti-slip role.

[0036] The electrode guide groove is arranged in the upper support plate 6. The electrode guide groove mainly plays a guiding and limiting role to ensure that the high-voltage curvature electrode 3 has a stable trajectory and accurate position when moving in the vertical direction. Therefore, the electrode guide groove is set to assist in spacing adjustment rather than directly used to adjust the spacing. It is convenient to adjust the electrode spacing to meet the requirements of samples of different thicknesses, and the upper and lower spacing and the pressure applied to the electrode can be adjusted according to the height adjustment screw knob 1.

[0037] The support frame includes: a ground base 5, an upper support plate 6 and an insulating support column 7, and the insulating support column 7 is tightly connected to the upper support plate 6 and the ground base 5 to ensure the stability of the device; Specifically, a height adjustment screw knob 1 is provided above the high-voltage curvature electrode 3. The height adjustment screw knob 1 and the upper support plate 6 adopt a threaded connection structure. Rotating the height adjustment screw knob 1 can drive the high-voltage curvature electrode 3 to move up and down in the vertical direction to adjust the distance between it and the grounded curvature electrode 4, and fix the set distance through a locking device to adapt to cable slice samples of different thicknesses.

[0038] The grounded curvature electrode 4 is mounted on a grounded base 5 , which is made of a high-strength metal material and has a large mass to enhance the stability of the overall structure during the test.

[0039] The upper support plate 6 is tightly connected to the ground base 5 below through the insulating support column 7. The insulating support column 7 is made of high-voltage and high-temperature resistant insulating material, has good structural strength and electrical isolation performance, and ensures the stability and insulation reliability of the entire electrode device under high-voltage test conditions.

[0040] Specifically, the real-time pressure detection device 2 is located below the high-voltage curvature electrode 3 and between the contact surface of the cable sample. It can detect the force applied to the sample through an embedded strain gauge or pressure-sensitive element and output an electrical signal for subsequent monitoring. This structure can be used to control the loading pressure and ensure the quality of the upper and lower electrodes fitting the cable sample and the uniformity of the stress during the experiment. In a preferred but non-limiting embodiment of the present invention, the real-time pressure detection device 2 is embedded with a pressure sensor in the bottom fitting surface or supporting frame of the high-voltage curvature electrode 3, which is used to detect in real time the contact pressure applied by the high-voltage curvature electrode 3 on the surface of the cable slice; the pressure sensor is connected to an external display module or a data acquisition module and can be used for closed-loop control of the experimental pressure.

[0041] Specifically, the temperature control heating device 8 is tightly mounted inside or at the bottom of the grounded curvature electrode 4. It uses a metal heating wire or heat conducting plate structure to achieve indirect heating of the cable sample through heat conduction. The heating device is powered and temperature regulated via an external temperature control interface, capable of maintaining the constant temperature environment required for the experiment. In a preferred but non-limiting embodiment of the present invention, a spirally or serpentinely arranged metal heating wire is embedded in the grounded curvature electrode 4, the heating wire is powered by an external temperature-controlled power supply, and the temperature is adjusted by a temperature control module; the outer shell of the grounded curvature electrode 4 is covered with a high-temperature resistant insulating material to prevent heat leakage.

[0042] The multi-environment simulation chamber 15 includes: a high-pressure end lead-out line 9, an upper valve 10, an upper channel 11, a flange observation window 12, a lower valve 13 and a lower channel 14.

[0043] The high-voltage lead-out line 9 is insulated and tightly connected to the multi-environment simulation cavity 15, ensuring that the high voltage is isolated from the cavity and meets the air-tightness requirements; the upper valve 10 and the upper channel 11, the lower valve 13 and the lower channel 14 cooperate to form a port that can be opened and closed at will, which can meet the air-tightness requirements of liquid circulation and vacuum.

[0044] Specifically, the high-voltage lead-out line 9 is an insulated high-voltage cable, one end of which is fixedly connected to the high-voltage curvature electrode 3, and the other end passes through the insulating closed structure of the multi-environment simulation cavity 15, and is connected to the high-voltage power supply output end, and is airtightly packaged through a sealing joint to avoid safety problems caused by leakage or breakdown at the high-voltage wiring point; the grounding curvature electrode 4 is connected to the ground wire through the grounding lead, and all electrical connection lines pass through the sealed lead hole of the cavity, and the interface is fixed with a sealing nut to prevent pressure relief and insulation breakdown.

[0045] Specifically, the multi-environment simulation chamber 15, encasing the curvature electrode device, is a sealed structure with a top cover and a base. An upper channel 11 and a lower channel 14 are located within the chamber. The upper valve 10, which works with the upper channel 11, and the lower valve 13, which works with the lower channel 14, form a freely switchable gas-liquid port structure, enabling environmental simulation functions such as liquid injection (e.g., insulating oil, water) and vacuuming. The chamber is constructed of pressure-resistant material to withstand the thermal expansion forces and pressure fluctuations that may occur during experiments.

[0046] Specifically, the flange observation window 12 is arranged at the center position of the top of the cavity and is fixed to the upper wall of the cavity by a bolt flange structure. The material thereof is made of tempered glass or transparent polycarbonate. It is used to observe the cable slices and discharge status under sealed conditions, facilitating the recording and visual analysis of the experimental process.

[0047] It is worth noting that, with regard to the electrode structure and its working process, the present invention optimizes key parameters such as the electrode central angle, temperature control range, and mechanical pressure from both theoretical and experimental aspects through electric-thermal-mechanical-environmental multi-physics field coupling modeling and simulation verification, ensuring that the device can still maintain uniform electric field distribution, stable temperature, and reliable structure under comprehensive stress conditions, providing a solid theoretical basis for the performance advantages of the present invention.

[0048] like Figure 4As shown, embodiment 2 of the present invention provides a curvature electrode performance testing method for cable slicing, comprising the following steps: S1. Prepare a cable slice sample to be tested and place it in the arc clamping area between the high-voltage curvature electrode 3 and the ground curvature electrode 4; In a preferred but non-restrictive embodiment of the present invention, the various components of the experimental device are cleaned and inspected to ensure that the height adjustment screw knob, real-time pressure detection device, electrode surface, flange observation window, heating device and the inside of the simulation cavity are free of dust, impurities, water vapor, etc., to ensure its insulation and sealing under high-voltage loading environment; prepare the cable slice sample to be tested and place it in the arc clamping area between the high-voltage curvature electrode and the ground curvature electrode according to its size.

[0049] S2. Rotate the height adjustment screw knob 1 to adjust the position of the high-voltage curvature electrode 3 so that the inner arc surface of the high-voltage curvature electrode 3 contacts the surface of the cable slice. When the pressure between the electrode and the cable reaches the set preload standard, stop adjusting and fix the height adjustment knob to complete the sample clamping and electrode bonding; In a preferred but non-limiting embodiment of the present invention, the position of the high-voltage curvature electrode 3 is adjusted by rotating the height adjustment screw knob 1, and slowly lowered until the inner arc surface of the high-voltage curvature electrode 3 contacts the surface of the cable slice; observe the value read by the real-time pressure detection device 2, and when the pressure reaches the set preload standard, stop adjusting and fix the height adjustment screw knob 1 to complete the sample clamping and the fitting of the high-voltage curvature electrode 3 and the grounding curvature electrode 4.

[0050] S3, start the temperature control heating device 8 to raise the temperature to the test set value, inject liquid or adjust the air pressure inside the multi-environment simulation cavity 15 until the internal environment of the cavity meets the set requirements, then close the valve and keep it sealed; In a preferred but non-restrictive embodiment of the present invention, according to the experimental requirements, the target temperature of the temperature-controlled heating device is set by an external temperature control system, the internal heating module of the lower electrode is started, the heating status is observed, and the temperature is ensured to rise steadily to the set value through the embedded sensor and maintained for a certain time to ensure a uniform thermal field, thereby simulating the heating status of the cable insulation under actual operating conditions.

[0051] Preferably, if the experiment requires simulating an oil bath, water injection, or vacuum environment, the upper or lower valve is opened as needed, and a corresponding liquid circulation device or vacuum pump is connected through the upper and lower channels to inject liquid or adjust the air pressure inside the simulation cavity until the internal environment of the cavity meets the set requirements. The valve is then closed and the seal is maintained. If a high-humidity or special gas environment is to be simulated, a gas medium of a certain humidity can be introduced into the cavity, and the valve is similarly closed and sealed after the set requirements are met.

[0052] S4. Start the high-voltage power supply and slowly increase the voltage to the preset value. Perform a breakdown test or partial discharge test, observe the status of the cable slices, and record relevant data. In a preferred but non-limiting embodiment of the present invention, the high-voltage lead-out line is connected, the high-voltage power supply is securely led to the high-voltage curvature electrode, and it is confirmed that the grounding curvature electrode is well grounded through the grounding base; on the premise of ensuring that all sealing interfaces are tightened and personnel have evacuated the test area, the voltage is slowly increased to the preset value to perform a breakdown test or a partial discharge experiment.

[0053] Further preferably, during the experiment, the discharge state, breakdown path and electrode contact of the cable slice are observed through the flange observation window; the discharge process image and waveform data can be recorded in conjunction with a high-speed camera or discharge detection instrument.

[0054] S5. After the experiment is completed, disconnect the high-voltage power supply, turn off the temperature control device, open the valve to release the pressure or liquid inside the simulation chamber, loosen the height adjustment screw knob to remove the upper electrode, take out the sample, and clean the residue on the surface of the electrode and cable; if the next round of experiments is required, repeat steps S1 to S4.

[0055] Compared with the prior art, the beneficial effects of the present invention include at least: (1) The present invention innovatively adopts an arc-shaped electrode structure that is highly compatible with the geometric curvature of the cable slice, enabling full structural contact between the electrode and the cable sample, thus avoiding the local air gap, electric field distortion, and premature discharge breakdown caused by uneven contact of traditional flat electrodes. This structure is particularly suitable for cable samples with a cylindrical shape, making the discharge path more realistic and controllable, and the electric field distribution more uniform, greatly improving the reliability and representativeness of the experimental data. At the same time, by optimizing the edge shape and coverage of the electrode, the uniformity of the electric field distribution is improved, avoiding local discharge caused by excessive edge field strength.

[0056] (2) The electrode structure introduces an adjustable spiral knob mechanism and a multi-dimensional precision adjustment component, which can achieve fine adjustment of the distance between the upper and lower electrodes and precise positioning in multiple degrees of freedom, adapt to samples of different thicknesses and shapes, and load specific stress conditions as needed. This adjustment structure not only has high mechanical precision, but also can maintain the stability of the set distance through the locking mechanism, ensuring that the force does not deform or deflect during the experiment. In conjunction with the pressure sensor set inside the electrode or on the contact surface, the contact pressure applied to the sample surface can be monitored in real time, achieving effective control of the electric-mechanical synergistic experimental conditions, which is a key means to study the local discharge, breakdown, and aging behavior of electrical insulating materials under pressure. The robust structural design also enables the device to adapt to nonlinear load shocks such as local discharge and breakdown, ensuring the safety and stability of the experimental process.

[0057] (3) A metal heating wire is innovatively embedded inside the lower electrode to form a three-dimensional composite heating structure. Through intelligent closed-loop control of the external temperature control system, the sample can be heated at a constant temperature within the set temperature range, creating a thermally stable experimental environment. This structure overcomes the problems of low thermal efficiency and uneven temperature distribution of traditional external heating methods, can respond quickly and accurately maintain the set temperature, and is suitable for studying the conductive behavior, breakdown strength evolution, and thermal aging laws of cable insulation materials in high-temperature environments, and has good application prospects.

[0058] (4) To meet the needs of experiments under complex media and environmental conditions, the present invention sets up a closed experimental chamber outside the electrode device and is equipped with two nozzles with switch valves. Insulating oil, water, or other liquid media can be injected according to the experimental requirements. Low-pressure environment simulation can also be achieved through the vacuum system, thereby supporting insulation performance testing under various conditions such as oil bath, water injection, and airtightness. This structure greatly expands the scope of experimental application and provides an operational platform for simulating actual operating conditions such as water tree aging, oil immersion overheating, high-humidity and high-temperature aging, and low-pressure vacuum breakdown.

[0059] (5) A transparent flange observation window is provided on the side of the device, which facilitates real-time observation of visible physical changes such as discharge phenomena, bubble formation, and crack propagation on the sample surface without destroying the test seal, providing interface support for the subsequent integration of high-frame-rate cameras or laser diagnostic systems. The design of this observation window not only improves the controllability and safety of the experiment, but also facilitates the visual tracking and data recording of discharge behavior and breakdown paths.

[0060] (6) The electrode assembly of the present invention adopts a modular design. The high-voltage curvature electrode and the ground curvature electrode are fixed by a detachable connection. Electrode heads with different curvature radii or sizes can be replaced according to test needs, thereby adapting to cable slice specimens of different specifications and facilitating the maintenance and upgrading of each component, further improving the scope of application and service life of the device.

[0061] In summary, the present invention has made comprehensive innovations in structural matching, adjustment flexibility, modular integration, intelligent control, temperature control accuracy, environmental simulation capability, and experimental visualization. It can be widely applied to the research on partial discharge, breakdown, and durability of samples such as cable slices, polymer insulation materials, and dielectric interface structures, and has high practicality and engineering promotion value.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A curvature electrode performance test device for cable slicing, Its characteristics are: It comprises: a curvature electrode device and a multi-environment simulation cavity (15), wherein the curvature electrode device is arranged inside the multi-environment simulation cavity (15); The curvature electrode device comprises: a height adjustment screw knob (1), a high-voltage curvature electrode (3), a grounded curvature electrode (4), a temperature control heating device (8), and a supporting frame; The high-voltage curvature electrode (3) and the grounding curvature electrode (4) are arranged relative to each other and are both located inside the support frame. The cable slice to be tested is placed between the high-voltage curvature electrode (3) and the grounding curvature electrode (4) to perform a performance test. A height adjustment screw knob (1) is provided above the high-voltage curvature electrode (3) for adjusting the distance between the high-voltage curvature electrode (3) and the grounding curvature electrode (4) and fixing the cable slice to be tested. The temperature control heating device (8) is connected to the grounding curvature electrode (4) for heating the cable slice. The curvature electrode device further comprises: a real-time pressure detection device (2), which is provided between the contact surface of the high-voltage curvature electrode (3) and the cable slice to be tested and is used to detect the magnitude of the force applied to the cable slice to be tested. The multi-environment simulation cavity (15) is connected to an external high-voltage power supply and provides a simulated test environment.

2. The curvature electrode performance testing device for cable slicing according to claim 1, characterized in that: The high-voltage curvature electrode (3) is a fan-shaped structure, the grounding curvature electrode (4) is an arc-shaped metal structure, and the cable slice to be tested is placed in the middle to form an electrode clamping space.

3. The curvature electrode performance testing device for cable slicing according to claim 2, characterized in that: The high-voltage curvature electrode (3) and the grounding curvature electrode (4) have the same central angle, which is 20-30°.

4. The curvature electrode performance testing device for cable slicing according to claim 1, characterized in that: The support frame comprises: a ground base (5), an upper support plate (6) and an insulating support column (7); The height adjustment screw knob (1) is threadedly connected to the upper support plate (6), and the position of the high-voltage curvature electrode (3) is adjusted by rotating the height adjustment screw knob (1). The grounding curvature electrode (4) is installed on the grounding base (5), and the upper support plate (6) is connected to the grounding base (5) through an insulating support column (7).

5. The curvature electrode performance testing device for cable slicing according to claim 1, characterized in that: The high-voltage curvature electrode (3) and the grounding curvature electrode (4) adopt a detachable modular installation structure, and motor components with different curvature radii or sizes can be replaced to adapt to cable slice samples of different specifications.

6. The curvature electrode performance testing device for cable slicing according to claim 1, characterized in that: The temperature control heating device (8) is installed inside or at the bottom of the grounded curvature electrode (4), and is connected to an external temperature control interface for power supply and temperature regulation, thereby achieving indirect heating of the cable slice to be tested.

7. The curvature electrode performance testing device for cable slicing according to claim 1, characterized in that: The grounded curvature electrode (4) is connected to the ground wire via a grounding lead, the grounding lead passes through a sealed lead hole of the multi-environment simulation cavity (15), and a sealing nut is used to fix the interface to prevent pressure relief and insulation breakdown.

8. The curvature electrode performance testing device for cable slicing according to claim 1, characterized in that: The multi-environment simulation chamber (15) comprises: a high-pressure end lead wire (9), an upper valve (10), an upper channel (11), a lower valve (13) and a lower channel (14); One end of the high-voltage lead wire (9) is fixedly connected to the high-voltage curvature electrode (3), and the other end passes through the multi-environment simulation cavity (15) and is connected to an external high-voltage power supply; the upper valve (10) and the upper channel (11), and the lower valve (13) and the lower channel (14) cooperate to form a port that can be opened and closed at will, for realizing different simulation environments.

9. The curvature electrode performance testing device for cable slicing according to claim 8, characterized in that: The multi-environment simulation cavity (15) further comprises: a flange observation window (12), wherein the flange observation window (12) is arranged on the outer wall of the multi-environment simulation cavity (15) and is used for observing cable slices and discharge states under a sealed condition.

10. A method for testing the performance of a curvature electrode for cable slicing, comprising: executing the curvature electrode performance testing device for cable slicing according to any one of claims 1 to 9, wherein: The following steps are involved: Prepare a cable slice sample to be tested and place it between the high-voltage curvature electrode (3) and the ground curvature electrode (4); Rotate the height adjustment screw knob (1) to adjust the position of the high-voltage curvature electrode (3). When the pressure between the high-voltage curvature electrode (3) and the cable slice to be tested reaches the test standard, stop adjusting and fix the height adjustment screw knob (1); Starting the temperature control heating device (8) to raise the temperature to a test set value, generating a simulated test environment for the multi-environment simulation cavity (15) and keeping it sealed; Start the high voltage power supply for testing, observe the status of the cable slice to be tested and record the relevant data to complete the test.

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