An insulator surface potential measuring device and method

Abstract

This invention discloses an insulator surface potential measuring device and method, comprising a housing having a sealed cavity, an air inlet, and an exhaust outlet; a high-voltage wiring assembly installed in the housing, with one end of the high-voltage wiring assembly extending into the cavity and the other end connected to a high-voltage power supply; a vacuum pump assembly with one end extending through the housing into the cavity; an electrostatic probe assembly including an electrostatic probe and a driving structure, the electrostatic probe and the driving structure being installed in the cavity and connected; a first central high-voltage conductor assembly disposed in the cavity and connected to one end of the high-voltage wiring assembly; a second central high-voltage conductor assembly disposed in the cavity and opposite to the first central high-voltage conductor assembly; and a first driving assembly, with the second central high-voltage conductor mounted on the first driving assembly. This invention overcomes the limitations of existing technologies in measuring the surface potential of insulators with complex geometries and improves measurement efficiency through the aforementioned control.

Description

Technical Field

[0001] This invention relates to the field of high voltage direct current transmission technology, and in particular to an insulator surface potential measuring device and method. Background Technology

[0002] my country's energy resources and load centers are extremely unevenly distributed, necessitating long-distance, high-capacity power transmission strategies to reduce line losses and improve power transmission efficiency. Compared to traditional transmission methods such as overhead lines and power cables, gas-insulated transmission lines (GILs) and gas-insulated switchgear (GIS), using SF6, SF6 / N2 mixed gases, or other environmentally friendly gases as insulation media, have gained widespread attention in the field of long-distance, high-capacity power transmission due to their unique technological advantages.

[0003] With the rapid development of ultra-high voltage direct current (UHVDC) transmission projects in my country, the application requirements of GIL (Gas Insulator) and GIS (Gas Insulator Geological Separator) in special environments are becoming increasingly urgent. However, under prolonged DC voltage, the charge accumulation on the surface of basin-type insulators has become one of the key factors limiting the operation of DC GIL / GIS. The large accumulation of charge on the insulator surface can cause electric field distortion, potentially leading to surface discharge and threatening the safe and stable operation of the equipment. Therefore, it is necessary to conduct in-depth research on the charge accumulation characteristics of DC GIL / GIS insulator surfaces. Existing GIL / GIS insulator surface potential measurement technologies are mainly designed for rotationally symmetric insulators with inclined surfaces or relatively simple geometric shapes, and they suffer from decreased measurement accuracy due to the decay of the insulator surface potential caused by excessively long measurement times. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing insulator surface potential measurement technology is limited by the geometry of the insulator and suffers from a decrease in measurement accuracy due to the decay of the insulator surface potential caused by excessive measurement time.

[0005] To address the aforementioned technical problems, the present invention provides an insulator surface potential measuring device, comprising:

[0006] The outer casing has a sealed cavity, an air inlet for filling with insulating gas, and an exhaust outlet for discharging the insulating gas, wherein the cavity is connected to the air inlet and the exhaust outlet;

[0007] A high-voltage wiring assembly is installed on the housing, with one end of the high-voltage wiring assembly extending into the cavity and the other end of the high-voltage wiring assembly connected to an external high-voltage power supply.

[0008] A vacuum assembly, one end of which extends through the outer shell into the cavity, to perform a vacuuming operation on the cavity;

[0009] An electrostatic probe assembly includes an electrostatic probe and a driving structure, wherein the electrostatic probe and the driving structure are installed in the cavity and the electrostatic probe is connected to the driving structure to scan the surface of an insulator through the driving structure.

[0010] The first central high-voltage conductor assembly is disposed within the cavity and connected to one end of the high-voltage wiring assembly;

[0011] A second central high-voltage conductor assembly is disposed within the cavity and is positioned opposite to the first central high-voltage conductor assembly. The end of the second central high-voltage conductor assembly facing the first central high-voltage conductor assembly is used to mount an insulator.

[0012] A first drive assembly is provided, and the second central high-voltage conductor is mounted on the first drive assembly to be connected to the first central high-voltage conductor assembly under the drive of the first drive assembly.

[0013] Furthermore, the high-voltage wiring assembly includes a high-voltage bushing and a high-voltage electrode conductor. The high-voltage bushing is installed on the housing, one end of the high-voltage electrode conductor passes through the high-voltage bushing and extends into the cavity, and the other end of the high-voltage electrode conductor is connected to an external high-voltage power supply.

[0014] Furthermore, the vacuum assembly includes a vacuum pump, an oil-gas separator, and a first ball valve. The vacuum pump is connected to the cavity, and an oil-gas separator is provided between the vacuum pump and the outer casing. The first ball valve is provided between the oil-gas separator and the outer casing.

[0015] Furthermore, the drive structure includes a mounting bracket, a horizontal drive unit, and a vertical drive unit. The vertical drive unit is mounted on the mounting bracket, the horizontal drive unit is connected to the vertical drive unit, and the electrostatic probe is mounted on the horizontal drive unit.

[0016] Furthermore, the vertical drive unit includes a first drive member, a first screw, and a first slider. The first drive member and the first screw are mounted on the mounting bracket. The output shaft of the first drive member is connected to the first screw, and the first slider is mounted on the first screw.

[0017] The horizontal drive unit includes a second drive member, a second screw, and a second slider. The second drive member is mounted on the first slider, and the second screw is connected to the output shaft of the second drive member. The second slider is mounted on the second screw, and the electrostatic probe is mounted on the second slider.

[0018] Furthermore, the first central high-voltage conductor assembly includes a first central high-voltage conductor and a first grounding sleeve. The first central high-voltage conductor is connected to one end of the high-voltage wiring assembly. The first grounding sleeve is arranged around the periphery of the first central high-voltage conductor, and there is a gap between the first grounding sleeve and the first central high-voltage conductor. The first grounding sleeve is connected to the grounding electrode lead.

[0019] Furthermore, the second central high-voltage conductor assembly includes a second central high-voltage conductor, a second grounding sleeve, and a support. The end of the second central high-voltage conductor facing away from the first central high-voltage conductor assembly is connected to the support. The second grounding sleeve is arranged around the periphery of the second central high-voltage conductor, and there is a gap between the second grounding sleeve and the second central high-voltage conductor.

[0020] Furthermore, the first drive assembly includes a third drive member, a first slide rail, a third screw, and a third slider. The third drive member is connected to the third screw, the third slider is slidably mounted on the first slide rail, and the third slider is connected to the third screw. The second central high-voltage conductor is mounted on the third slider.

[0021] Furthermore, it also includes a second driving assembly, which includes a fourth driving member, a second slide rail, a fourth screw, and a fourth slider. The fourth driving member is connected to the fourth screw, the fourth slider is slidably mounted on the second slide rail, and the fourth slider is connected to the fourth screw. The first driving assembly is mounted on the fourth slider.

[0022] The present invention also provides a method for measuring the surface potential of an insulator, applied to the insulator surface potential measuring device as described above, the method comprising the following steps:

[0023] Expel the air from the cavity until the cavity is in a vacuum state;

[0024] Insulating gas is injected into the cavity, and inflation is stopped once the gas pressure in the cavity meets the requirements.

[0025] The electrostatic probe is moved to a designated position by the drive structure, and the second central high-voltage conductor assembly is connected to the first central high-voltage conductor assembly by the first drive component to apply DC high voltage to the insulator.

[0026] After the pressurization is completed, the external voltage is removed, the drive structure is controlled to move the electrostatic probe to the designated position, and the second central high-voltage conductor assembly is controlled by the first drive assembly to move the insulator to the designated position.

[0027] The electrostatic probe then scans the surface of the insulator, and the step size of the electrostatic probe scanning path in the horizontal direction satisfies the following formula:

[0028]

[0029] Where D is the side length of the square base of the electrostatic probe, L is the diameter of the insulator, and x is the step size of the electrostatic probe scanning path in the horizontal direction.

[0030] After the electrostatic probe has completed scanning the surface potential of the insulator, the insulating gas is discharged from the cavity.

[0031] Compared with the prior art, the insulator surface potential measuring device and method of this invention have the following advantages:

[0032] The second central high-voltage conductor assembly in this embodiment of the invention is used to install insulators, while the first central high-voltage conductor assembly is connected to the high-voltage wiring assembly, together forming the core part of electric field generation. This simulates the electric field distribution under actual working conditions and is used to control the movement of the second central high-voltage conductor assembly, enabling it to connect with the first central high-voltage conductor assembly under drive. The electrostatic probe is controlled by the drive structure to scan the surface of the insulator, achieving accurate measurement of the surface potential of the insulator. This solves the limitations of the prior art in measuring the surface potential of insulators with complex geometries, and improves the measurement efficiency through the above control. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the first angle structure of the insulator surface potential measuring device provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the second angle structure of the insulator surface potential measuring device provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the insulator surface potential measuring device provided in an embodiment of the present invention, excluding the housing;

[0036] Figure 4 This is a schematic diagram of the electrostatic probe assembly provided in an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of the second central high-voltage conductor assembly, the first driving assembly, and the second driving assembly provided in an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the structure of the electrostatic probe and insulator provided in an embodiment of the present invention;

[0039] Figure 7This is a schematic diagram of the electrostatic probe scanning trajectory of the insulator surface potential measuring device provided in an embodiment of the present invention;

[0040] In the diagram, 1. Outer casing; 11. Second ball valve; 12. First air inlet; 13. Second air inlet; 14. Exhaust port; 2. High-voltage wiring assembly; 21. High-voltage bushing; 22. High-voltage electrode conductor; 3. Vacuum assembly; 31. Vacuum pump; 32. Oil-gas separator; 33. First ball valve; 4. Electrostatic probe assembly; 41. Electrostatic probe; 42. Drive structure; 421. Mounting bracket; 422. Horizontal drive unit; 4221. Second drive component; 4222. Second screw; 4223. Second slider; 423. Vertical drive unit; 4231. First drive component. Components; 4232, First Screw; 4233, First Slider; 5, First Central High Voltage Conductor Assembly; 51, First Central High Voltage Conductor; 52, First Grounding Sleeve; 6, Second Central High Voltage Conductor Assembly; 61, Second Central High Voltage Conductor; 62, Second Grounding Sleeve; 63, Bracket; 7, First Drive Assembly; 71, Third Drive Component; 72, First Slide Rail; 73, Third Screw; 74, Third Slider; 8, Second Drive Assembly; 81, Fourth Drive Component; 82, Second Slide Rail; 83, Fourth Screw; 84, Fourth Slider; 9, Base; 10, Moving Platform. Detailed Implementation

[0041] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0042] like Figures 1 to 3As shown, the present invention provides an insulator surface potential measuring device, including a housing 1, a high-voltage wiring assembly 2, a vacuum assembly 3, an electrostatic probe assembly 4, a first central high-voltage conductor assembly 5, a second central high-voltage conductor assembly 6, and a first driving assembly 7. The outer casing 1 has a sealed cavity, an inlet for filling with insulating gas, and an outlet 14 for discharging insulating gas. The cavity is connected to the inlet and outlet 14. A high-voltage wiring assembly 2 is installed on the outer casing 1, with one end of the high-voltage wiring assembly 2 extending into the cavity and the other end connected to a high-voltage power supply. One end of a vacuum assembly 3 extends through the outer casing 1 into the cavity to perform a vacuum operation. An electrostatic probe assembly 4 includes an electrostatic probe 41 and a drive structure 42. The electrostatic probe 41 and the drive structure 42 are installed in the cavity and connected to the drive structure 42 to scan the surface of the insulator. A first central high-voltage conductor assembly 5 is disposed in the cavity and connected to one end of the high-voltage wiring assembly 2. A second central high-voltage conductor assembly 6 is disposed in the cavity and is positioned opposite to the first central high-voltage conductor assembly 5. The end of the second central high-voltage conductor assembly 6 facing the first central high-voltage conductor assembly 5 is used to install the insulator. The second central high-voltage conductor 61 is installed on a first drive assembly 7 to connect with the first central high-voltage conductor assembly 5 under the drive of the first drive assembly 7.

[0043] The sealed cavity in this embodiment is used to simulate the actual working environment. Its air inlet and outlet 14 ensure the introduction and discharge of insulating gases such as C4F7N, CO2, SF6, N2, CF3I, and compressed air, thereby creating a closed, isolated testing environment. The high-voltage wiring assembly 2 is used to connect to an external high-voltage power supply, with one end extending into the cavity to provide the necessary voltage conditions for testing. Furthermore, the vacuum assembly 3 allows for vacuuming of the cavity, helping to remove any impurities or air that may be present, ensuring the purity of the testing environment and reducing the influence of external factors on the measurement results.

[0044] Based on the above structure, the second central high-voltage conductor assembly 6 is used to install the insulator, while the first central high-voltage conductor assembly 5 is connected to the high-voltage wiring assembly 2, together forming the core part of electric field generation, simulating the electric field distribution under actual working conditions, and used to control the movement of the second central high-voltage conductor assembly 6, so that it can be connected to the first central high-voltage conductor assembly 5 under drive. The electrostatic probe 41 is controlled by the drive structure 42 to scan the surface of the insulator, realizing accurate measurement of the surface potential of the insulator. This solves the limitations of the prior art in measuring the surface potential of insulators with complex geometries, and improves the measurement efficiency through the above control.

[0045] Furthermore, the high-voltage wiring assembly 2 includes a high-voltage bushing 21 and a high-voltage electrode conductor 22. The high-voltage bushing 21 is installed on the housing 1. One end of the high-voltage electrode conductor 22 passes through the high-voltage bushing 21 and extends into the cavity, so as to achieve electrical isolation between the high-voltage electrode conductor 22 and the cavity through the high-voltage bushing 21. This ensures that even under high-voltage conditions, current can be effectively prevented from flowing directly through the housing 1, avoiding possible short-circuit risks and protecting the safety of the entire system and operators. The other end of the high-voltage electrode conductor 22 is connected to an external high-voltage power supply, which is responsible for introducing the voltage of the external high-voltage power supply into the cavity to provide the required electric field environment for the experiment.

[0046] Furthermore, the vacuum assembly 3 includes a vacuum pump 31, an oil-gas separator 32, and a first ball valve 33. The vacuum pump 31 is connected to the cavity, and an oil-gas separator 32 is provided between the vacuum pump 31 and the outer shell 1. The first ball valve 33 is provided between the oil-gas separator 32 and the outer shell 1.

[0047] In this embodiment, the vacuum pump 31 is mainly used to extract gas from the cavity to create a low-pressure environment. Simultaneously, the oil-gas separator 32 ensures that while gas is being extracted, the oil in the vacuum pump 31 is separated and recovered, preventing oil mist from contaminating the internal environment of the cavity and maintaining its cleanliness. This also avoids oil mist being released into the external environment and causing pollution. Furthermore, by opening or closing the first ball valve 33, the vacuuming process can be started or stopped, or the pumping rate can be adjusted, thereby achieving precise control of the gas pressure within the cavity.

[0048] It should be noted that in this embodiment, the cavity is also provided with a second ball valve 11. The air inlet includes a first air inlet 12 and a second air inlet 13. The second ball valve 11 is connected to the first air inlet 12, the second air inlet 13 and the exhaust port 14. The first air inlet 12 and the second air inlet 13 each include an air supply source and an air valve. The air supply source is connected to the cavity through a pipeline, and the air valve is installed on the air supply pipeline to control the start and stop of the air supply. The air supply source includes C4F7N, CO2, SF6, N2, CF3I and compressed air, etc.

[0049] like Figure 4 As shown, the drive structure 42 includes a mounting bracket 421, a horizontal drive unit 422, and a vertical drive unit 423. The vertical drive unit 423 is mounted on the mounting bracket 421. The horizontal drive unit 422 is connected to the vertical drive unit 423. The electrostatic probe 41 is mounted on the horizontal drive unit 422 and is responsible for moving the electrostatic probe 41 along the horizontal direction (usually the X-axis or Y-axis). By precisely controlling the horizontal displacement, the potential of different areas on the insulator surface can be measured. The vertical drive unit 423 cooperates with the horizontal drive unit 422 and is responsible for controlling the movement of the electrostatic probe 41 in the vertical direction (usually the Z-axis).

[0050] This embodiment, through the coordinated operation of the horizontal drive unit 422 and the vertical drive unit 423, enables precise positioning of the electrostatic probe 41 in three-dimensional space, ensuring the accuracy of the selection of measurement points and the movement path. Furthermore, through preset program control, a series of measurement tasks can be automatically completed, avoiding errors that may arise from manual operation and reducing the workload of experimental personnel. The bracket 63 is made of polytetrafluoroethylene, and the electrostatic probe 41 is led out from inside the cavity via a lead flange, thus connecting to the electrostatic potentiometer.

[0051] Furthermore, the vertical drive unit 423 includes a first drive member 4231, a first screw 4232, and a first slider 4233. The first drive member 4231 and the first screw 4232 are mounted on the mounting bracket 421. The output shaft of the first drive member 4231 is connected to the first screw 4232, and the first slider 4233 is mounted on the first screw 4232. In this embodiment, the first drive member 4231 is a motor, which is responsible for providing power. It is connected to the first screw 4232 through its output shaft, converting the rotational motion of the motor into linear motion. When the motor rotates, the first screw 4232 rotates accordingly, and the first slider 4233 moves linearly along the screw, realizing vertical movement. By controlling the forward and reverse rotation of the motor, the up and down movement of the first slider 4233 can be controlled, thereby realizing the vertical positioning of the electrostatic probe 41.

[0052] The horizontal drive unit 422 includes a second drive member 4221, a second screw 4222, and a second slider 4223. The second drive member 4221 is mounted on the first slider 4233, and the second screw 4222 is connected to the output shaft of the second drive member 4221. The second slider 4223 is mounted on the second screw 4222, and the electrostatic probe 41 is mounted on the second slider 4223. Understandably, in this embodiment, the second drive member 4221 is also a motor, mounted on the first slider 4233, ensuring that the horizontal drive unit 422 can move vertically together with the first slider 4233. When the second drive member 4221 rotates, the second screw 4222 rotates, and the second slider 4223 moves linearly along the screw, achieving horizontal movement. In this embodiment, by controlling the rotation of the second drive member 4221, the position of the electrostatic probe 41 in the horizontal direction can be precisely controlled. Combined with vertical movement, precise positioning of the electrostatic probe 41 in three-dimensional space can be achieved, improving the reliability and accuracy of the measurement data.

[0053] Furthermore, the first central high-voltage conductor assembly 5 includes a first central high-voltage conductor 51 and a first grounding sleeve 52. The first central high-voltage conductor 51 is connected to one end of the high-voltage wiring assembly 2 to receive voltage input from the high-voltage power supply. The first grounding sleeve 52 is arranged around the periphery of the first central high-voltage conductor 51, and there is a gap between the first grounding sleeve 52 and the first central high-voltage conductor 51. The first grounding sleeve 52 is connected to the grounding electrode lead.

[0054] Based on the above structure, the first central high-voltage conductor 51 generates an electric field around itself after receiving voltage from the high-voltage power supply. By adjusting the applied voltage, the strength and distribution of the electric field can be controlled, providing the necessary electric field environment for measuring the surface potential change of the insulator. The first grounding sleeve 52 is connected to the ground through the grounding electrode lead, which can promptly discharge any static electricity or fault current that may be generated, further ensuring the safety of experimental personnel and equipment.

[0055] It should be noted that the first grounding sleeve 52 is a cylindrical barrel, and the axis of the barrel coincides with the first central high-voltage conductor 51.

[0056] like Figure 5 As shown, the second central high-voltage conductor assembly 6 includes a second central high-voltage conductor 61, a second grounding sleeve 62, and a support 63. The end of the second central high-voltage conductor 61 facing away from the first central high-voltage conductor assembly 5 is connected to the support 63 to ensure its stable position in the experiment. The second grounding sleeve 62 is arranged around the periphery of the second central high-voltage conductor 61, and there is a gap between the second grounding sleeve 62 and the second central high-voltage conductor 61.

[0057] Based on the above structure, the second central high-voltage conductor 61 and the first central high-voltage conductor assembly 5 work together to form an electric field environment. The first grounding sleeve 52 is connected to the ground through the grounding electrode lead, which can promptly discharge any static electricity or fault current that may be generated, further ensuring the safety of experimental personnel and equipment. The spacing design between the second grounding sleeve 62 and the second central high-voltage conductor 61 also plays a role in electrical isolation, protecting experimental personnel from the risk of accidental electric shock.

[0058] It should be noted that the second grounding sleeve 62 is a cylindrical barrel, and the axis of the barrel coincides with the second central high-voltage conductor 61. Preferably, the first central high-voltage conductor 51 and the second central high-voltage conductor 61 are on the same straight line.

[0059] Furthermore, the first drive assembly 7 includes a third drive member 71, a first slide rail 72, a third screw 73, and a third slider 74. The third drive member 71 is connected to the third screw 73. The third slider 74 is slidably mounted on the first slide rail 72 and is connected to the third screw 73. The second central high-voltage conductor 61 is mounted on the third slider 74.

[0060] In this embodiment, the third driving component 71 serves as the power source for the first driving assembly 7. It can be an electric motor or a servo motor to provide power for linear or rotary motion. The first slide rail 72 provides a track for the linear motion of the third slider 74, ensuring its smooth sliding along a predetermined path, which is the basis for achieving precise positioning and stable motion. Furthermore, through the interaction between the thread and the third slider 74, the rotary motion of the third driving component 71 is converted into linear motion, realizing the precise displacement of the third slider 74 on the first slide rail 72, and driving the second central high-voltage conductor 61 to move within the experimental space.

[0061] Furthermore, it also includes a second drive assembly 8, which includes a fourth drive member 81, a second slide rail 82, a fourth screw 83, and a fourth slider 84. The fourth drive member 81 is connected to the fourth screw 83, the fourth slider 84 is slidably mounted on the second slide rail 82, and the fourth slider 84 is connected to the fourth screw 83. The first drive assembly 7 is mounted on the fourth slider 84.

[0062] In this embodiment, the fourth driving component 81 serves as the power source for the second driving assembly 8. It can be a motor or a servo motor, responsible for providing the power required for linear motion and controlling the movement of the entire second driving assembly 8. The second slide rail 82 provides guidance for the fourth slider 84, ensuring that it can slide smoothly along a predetermined path, and is the basic component for realizing linear motion. The fourth screw 83 is connected to the fourth driving component 81 and interacts with the fourth slider 84 through its threads, converting the rotational motion of the fourth driving component 81 into linear motion, thereby enabling the fourth slider 84 to be precisely displaced on the second slide rail 82.

[0063] Furthermore, the cavity is equipped with three observation windows for observing the movement of the insulators inside. In addition, the cavity is also equipped with a resistance vacuum gauge, a safety valve, and a pressure sensor. The resistance vacuum gauge is used to detect the vacuum level of the cavity during the evacuation process, the pressure sensor is used to measure the pressure of the insulating gas entering the cavity, and the safety valve is used to control the cavity pressure to prevent overpressure.

[0064] In this embodiment, a control and display component is also included. The control and display component is connected to the resistance vacuum gauge, the pressure sensor, the vacuum pump 31, the horizontal drive unit 422, the vertical drive unit 423, the first drive component 7, and the second drive component 8, respectively.

[0065] In addition, it includes a base 9 and a mobile platform 10. The housing 1 and the mobile platform 10 are both mounted on the base 9, and the mobile platform 10 is located in the cavity and is connected to the base 9 by a guide rail. The housing is provided with a door for the mobile platform 10 to slide out of or into the cavity. The second drive assembly 8, the first central high voltage conductor assembly 5 and the drive structure 42 are all mounted on the mobile platform 10.

[0066] like Figure 6 and Figure 7 As shown, the present invention also provides a method for measuring the surface potential of an insulator, applied to the insulator surface potential measuring device described above. The method for measuring the surface potential of an insulator includes the following steps:

[0067] S110. Expel the air from the cavity until the cavity is in a vacuum state;

[0068] Before this step, a voltage-applying circuit needs to be connected. A DC voltage source with an output voltage of 0 to ±100kV is connected to the high-voltage electrode conductor 22 of the cavity through a protective resistor. Before the experiment, the insulator sample is first wiped with anhydrous ethanol and dried in an oven for 10 hours to remove residual parasitic charges on the surface of the insulator. Then, the opening and closing door of the cavity is opened, the moving platform 10 is moved outside the cavity, the insulator is installed on the second central high-voltage conductor 61, the moving platform 10 is moved inside the cavity, and the opening and closing door of the cavity is closed.

[0069] Then, turn on the vacuum pump 31 and the first ball valve 33 to purge the air from the cavity. Once the cavity is in a vacuum state, turn off the first ball valve 33 and the vacuum pump 31.

[0070] S120. Pour insulating gas into the cavity and stop filling the cavity when the gas pressure meets the requirements.

[0071] Open the air valve of the first air inlet 12 or the second air inlet 13 and the second ball valve 11 to flush insulating gases such as C4F7N, CO2, SF6, N2, CF3I and compressed air into the cavity. Stop the inflation after the air pressure meets the requirements and close the air valve of the first air inlet 12 or the second air inlet 13 and the second ball valve 11.

[0072] S130. Move the electrostatic probe 41 to the designated position through the drive structure 42, and control the second central high voltage conductor assembly 6 to connect with the first central high voltage conductor assembly 5 through the first drive assembly 7, so as to apply DC high voltage to the insulator.

[0073] The first slider 4233, the second slider 4223, the third slider 74, and the fourth slider 84 are controlled to move the electrostatic probe 41, the insulator, and the second grounding sleeve 62 to the pressurized position, so that the second central high-voltage conductor 61 is connected to the first central high-voltage conductor 51 to achieve communication with the high-voltage electrode conductor 22, and the insulator outer insert is made to fit with the second grounding sleeve 62. At this time, the first central high-voltage conductor 51 and the first grounding sleeve 52, the second central high-voltage conductor 61 and the second grounding sleeve 62 together with the insulator form a coaxial cylindrical electrode structure, and DC high voltage is applied to the insulator through the central high-voltage conductor; at the same time, the electrostatic probe 41 is moved away from the coaxial cylindrical electrode structure.

[0074] S140. After the pressurization is completed, the external voltage is removed, the drive structure 42 is controlled to move the electrostatic probe 41 to the designated position, and the second central high voltage conductor assembly 6 is controlled by the first drive assembly 7 to move the insulator to the designated position.

[0075] In this step, the first slider 4233, the second slider 4223, the third slider 74, and the fourth slider 84 are controlled to move the electrostatic probe 41, the insulator, and the second grounding sleeve 62 to the measurement position. The third slider 74 is controlled to move the insulator to the right, and the fourth slider 84 is controlled to move the fourth grounding sleeve to the right so that the insulator is in a suspended state. The first slider 4233 and the second slider 4223 are controlled to move the electrostatic probe 41 to a position close to the surface of the insulator.

[0076] S150. Subsequently, the electrostatic probe 41 scans the surface of the insulator. The step size of the scanning path of the electrostatic probe 41 in the horizontal direction satisfies the following formula:

[0077]

[0078] Where D is the side length of the square base of the electrostatic probe 41, L is the diameter of the insulator, and x is the step size of the scanning path of the electrostatic probe 41 in the horizontal direction; in addition, I is the distance between the starting scanning path and the boundary of the insulator, and I≤D / 2.

[0079] In this embodiment, the end face of the electrostatic probe 41 is square, and the data measured by the electrostatic probe 41 is the average value of the potential of the entire end face coverage area. If the scanning path is too dense, it will increase the scanning time required by the electrostatic probe 41 and reduce efficiency; if the scanning path is too sparse, the scanning path of the electrostatic probe 41 will not be able to cover the entire insulator, and the test results will not reflect the surface potential distribution of the entire insulator.

[0080] It should be noted that the distance between the scanning trajectory and the insulator and the size of the electrostatic probe must satisfy the following formula to achieve more accurate measurement results:

[0081] d = 3mm, D ≥ 15mm

[0082]

[0083] d = 1mm, D < 5mm

[0084] In the formula: D is the side length of the square base of the electrostatic probe, and d is the vertical distance from the center point of the electrostatic probe to the surface of the insulator. Among them, the electrostatic probe 41 is a Ke lvin oscillating active electrostatic probe, which can measure the potential and potential distribution of the insulator surface without contacting the surface of the test object.

[0085] S160. After the electrostatic probe 41 completes the scanning of the insulator surface potential, the insulating gas is discharged from the cavity.

[0086] It should be noted that, in order to adapt to the requirements of various working conditions, the surface of the insulator in the GIL / GIS system is mostly an irregular shape composed of inclined and curved surfaces. Through the cooperation of the first drive component 7, the second drive component 8 and the drive structure 42, it is suitable for the surface potential measurement of insulators with various complex shapes, and can achieve high efficiency in measuring the surface potential of insulators, thereby avoiding the problem of decreased measurement accuracy caused by the attenuation of the surface potential of insulators due to excessive measurement time.

[0087] In summary, the embodiments of the present invention provide an insulator surface potential measuring device and method. Through the cooperation of the horizontal drive unit 422 and the vertical drive unit 423, the electrostatic probe 41 can move in the front-back and up-down directions, and in conjunction with the first drive assembly 7, the insulator can move in the left-right direction. This allows the electrostatic probe 41 to scan the entire insulator surface without being limited by the insulator's geometric shape. The measurement method is simple to operate, convenient to use, and highly automated. Furthermore, the device can simulate the actual operating environment of a GIL / GIS system, including high-pressure insulating gas atmospheres and coaxial cylindrical electrode structures, among other actual operating conditions.

[0088] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A device for measuring the surface potential of an insulator, characterized in that, include The outer casing has a sealed cavity, an air inlet for filling with insulating gas, and an exhaust outlet for discharging the insulating gas, wherein the cavity is connected to the air inlet and the exhaust outlet; A high-voltage wiring assembly is installed on the housing, with one end of the high-voltage wiring assembly extending into the cavity and the other end of the high-voltage wiring assembly connected to a high-voltage power supply. The high-voltage wiring assembly includes a high-voltage bushing and a high-voltage electrode conductor. The high-voltage bushing is installed on the housing, one end of the high-voltage electrode conductor passes through the high-voltage bushing and extends into the cavity, and the other end of the high-voltage electrode conductor is connected to a high-voltage power supply. A vacuum assembly, one end of which extends through the outer shell into the cavity, to perform a vacuuming operation on the cavity; An electrostatic probe assembly includes an electrostatic probe and a driving structure, wherein the electrostatic probe and the driving structure are installed in the cavity, and the electrostatic probe is connected to the driving structure to scan the surface of an insulator through the driving structure. A first central high-voltage conductor assembly is disposed within the cavity and connected to one end of the high-voltage wiring assembly. The first central high-voltage conductor assembly includes a first central high-voltage conductor and a first grounding sleeve. The first central high-voltage conductor is connected to one end of the high-voltage wiring assembly. The first grounding sleeve is arranged around the periphery of the first central high-voltage conductor, and there is a gap between the first grounding sleeve and the first central high-voltage conductor. The first grounding sleeve is connected to a grounding electrode lead. A second central high-voltage conductor assembly is disposed within the cavity and is positioned opposite to the first central high-voltage conductor assembly. The end of the second central high-voltage conductor assembly facing the first central high-voltage conductor assembly is used to mount an insulator. The second central high-voltage conductor assembly includes a second central high-voltage conductor, a second grounding sleeve, and a support. The end of the second central high-voltage conductor facing away from the first central high-voltage conductor assembly is connected to the support. The second grounding sleeve is arranged around the periphery of the second central high-voltage conductor, and there is a gap between the second grounding sleeve and the second central high-voltage conductor. A first drive assembly is provided, and the second central high-voltage conductor is mounted on the first drive assembly to be connected to the first central high-voltage conductor assembly under the drive of the first drive assembly.

2. The insulator surface potential measuring device according to claim 1, characterized in that, The vacuum assembly includes a vacuum pump, an oil-gas separator, and a first ball valve. The vacuum pump is connected to the cavity, and an oil-gas separator is provided between the vacuum pump and the outer shell. The first ball valve is provided between the oil-gas separator and the outer shell.

3. The insulator surface potential measuring device according to claim 1, characterized in that, The drive structure includes a mounting bracket, a horizontal drive unit, and a vertical drive unit. The vertical drive unit is mounted on the mounting bracket, the horizontal drive unit is connected to the vertical drive unit, and the electrostatic probe is mounted on the horizontal drive unit.

4. The insulator surface potential measuring device according to claim 3, characterized in that, The vertical drive unit includes a first drive member, a first screw, and a first slider. The first drive member and the first screw are mounted on the mounting bracket. The output shaft of the first drive member is connected to the first screw, and the first slider is mounted on the first screw. The horizontal drive unit includes a second drive member, a second screw, and a second slider. The second drive member is mounted on the first slider, and the second screw is connected to the output shaft of the second drive member. The second slider is mounted on the second screw, and the electrostatic probe is mounted on the second slider.

5. The insulator surface potential measuring device according to claim 1, characterized in that, The first drive assembly includes a third drive member, a first slide rail, a third screw, and a third slider. The third drive member is connected to the third screw, the third slider is slidably mounted on the first slide rail, and the third slider is connected to the third screw. The second central high-voltage conductor is mounted on the third slider.

6. The insulator surface potential measuring device according to claim 5, characterized in that, It also includes a second drive assembly, which includes a fourth drive member, a second slide rail, a fourth screw, and a fourth slider. The fourth drive member is connected to the fourth screw, the fourth slider is slidably mounted on the second slide rail, and the fourth slider is connected to the fourth screw. The first drive assembly is mounted on the fourth slider.

7. A method for measuring the surface potential of an insulator, characterized in that, The insulator surface potential measuring device as described in any one of claims 1-6, the insulator surface potential measuring method includes the following steps: Expel the air from the cavity until the cavity is in a vacuum state; Insulating gas is filled into the cavity, and filling is stopped once the gas pressure in the cavity meets the requirements. The electrostatic probe is moved to a designated position by the drive structure, and the second central high-voltage conductor assembly is connected to the first central high-voltage conductor assembly by the first drive component to apply DC high voltage to the insulator. After the pressurization is completed, the external voltage is removed, the drive structure is controlled to move the electrostatic probe to the designated position, and the second central high-voltage conductor assembly is controlled by the first drive assembly to move the insulator to the designated position. The electrostatic probe then scans the surface of the insulator, and the step size of the electrostatic probe scanning path in the horizontal direction satisfies the following formula: ； Where D is the side length of the square base of the electrostatic probe, L is the diameter of the insulator, and x is the step size of the electrostatic probe scanning path in the horizontal direction. After the electrostatic probe has completed scanning the surface potential of the insulator, the insulating gas is discharged from the cavity.

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