Insulator surface potential measuring device and measuring method

Abstract

The invention discloses an insulator surface potential measuring device and method, and the device comprises a housing which is provided with a sealed cavity, an air inlet, and an air outlet. The high-voltage wiring assembly is mounted on the shell, one end of the high-voltage wiring assembly extends into the cavity, and the other end of the high-voltage wiring assembly is externally connected with a high-voltage power supply; one end of the vacuumizing assembly penetrates through the shell and extends into the cavity; the electrostatic probe assembly comprises an electrostatic probe and a driving structure, the electrostatic probe and the driving structure are installed in the cavity, and the electrostatic probe is connected with the driving structure; the first central high-voltage conductor assembly is arranged in the cavity and is connected with one end of the high-voltage wiring assembly; the second central high-voltage conductor assembly is arranged in the cavity and is opposite to the first central high-voltage conductor assembly; and the second central high-voltage conductor is mounted on the first driving assembly. According to the invention, the limitation of measuring the surface potential of the insulator in a complex geometrical shape in the prior art is solved, and the measurement efficiency is improved through the control.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage direct current transmission, and in particular to an insulator surface potential measuring device and a measuring method. Background Art

[0002] my country's energy resources and load center distribution are extremely unbalanced, and long-distance large-capacity transmission strategies are usually adopted to reduce line losses and improve power transmission efficiency. Compared with traditional transmission methods, such as overhead lines and power cables, gas-insulated transmission lines (GIL) and gas-insulated switchgear (GIS) with SF6, SF6 / N2 mixed gas or other environmentally friendly gases as insulating media have attracted widespread attention in the field of long-distance large-capacity transmission due to their unique technical advantages.

[0003] With the rapid development of UHV DC transmission projects in my country, the application demand for GIL and GIS in special environments has become more urgent. However, under the action of long-term DC voltage, the charge accumulation problem on the surface of pot-type insulators has become one of the key factors limiting the operation of DC GIL / GIS. Since the large amount of charge accumulation on the surface of the insulator will cause electric field distortion, which may lead to surface discharge and threaten the safe and stable operation of the equipment, it is necessary to study the surface charge accumulation characteristics of DC GIL / GIS insulators in depth. The existing GIL / GIS insulator surface potential measurement technology is mainly aimed at insulators with inclined surfaces or simple geometric shapes. The surface potential of the insulator is decayed due to the long measurement time, which leads to the problem of reduced measurement accuracy. 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 geometric shape of the insulator, and there is a problem of reduced measurement accuracy due to the attenuation of the insulator surface potential caused by the long measurement time.

[0005] In order to solve the above technical problems, the present invention provides an insulator surface potential measuring device, comprising:

[0006] The housing has a sealed cavity, an air inlet for filling with insulating gas, and an exhaust port for exhausting the insulating gas, wherein the cavity is in communication with the air inlet and the exhaust port;

[0007] A high-voltage wiring assembly is installed in the housing, and one end of the high-voltage wiring assembly extends into the cavity, and the other end of the high-voltage wiring assembly is externally connected to a high-voltage power supply;

[0008] A vacuum assembly, one end of which passes through the housing and extends into the cavity to perform a vacuum operation on the cavity;

[0009] An electrostatic probe assembly, comprising 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 the insulator through the driving structure;

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

[0011] a second central high-voltage conductor assembly, disposed in the cavity and opposite to the first central high-voltage conductor assembly, wherein an end of the second central high-voltage conductor assembly facing the first central high-voltage conductor assembly is used for mounting an insulator; and

[0012] A first driving component, wherein the second central high-voltage conductor is installed on the first driving component to be connected with the first central high-voltage conductor component under the drive of the first driving component.

[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 shell, one end of the high-voltage electrode conductor is passed through the high-voltage bushing and extends into the cavity, and the other end of the high-voltage electrode conductor is externally connected to a high-voltage power supply.

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

[0015] Further, the driving structure includes a mounting frame, a horizontal driving unit and a vertical driving unit, the vertical driving unit is mounted on the mounting frame, the horizontal driving unit is connected to the vertical driving unit, and the electrostatic probe is mounted on the horizontal driving unit;

[0016] Further, the vertical driving unit includes a first driving member, a first screw rod and a first slider, the first driving member and the first screw rod are mounted on the mounting frame, the output shaft of the first driving member is connected to the first screw rod, and the first slider is mounted on the first screw rod;

[0017] The horizontal driving unit includes a second driving member, a second screw and a second slider. The second driving member is installed on the first slider, and the second screw is connected to the output shaft of the second driving member. The second slider is installed on the second screw, and the electrostatic probe is installed 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 on the circumference of the first central high-voltage conductor, and there is a gap between the first grounding sleeve and the first central high-voltage conductor, and 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 bracket, the end of the second central high-voltage conductor facing away from the first central high-voltage conductor assembly is connected to the bracket, the second grounding sleeve is arranged on the circumference 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 installed on the first slide rail, and the third slider is connected to the third screw, and the second center high-voltage conductor is installed on the third slider.

[0021] Furthermore, it also includes a second drive component, which includes a fourth drive member, a second slide rail, a fourth screw rod and a fourth slider, the fourth drive member is connected to the fourth screw rod, the fourth slider is slidably installed on the second slide rail, and the fourth slider is connected to the fourth screw rod, and the first drive component is installed on the fourth slider.

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

[0023] Exhausting 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 when the gas pressure in the cavity meets the requirement;

[0025] Move the electrostatic probe to a specified position through the driving structure, and control the second central high-voltage conductor assembly to be connected to the first central high-voltage conductor assembly through the first driving assembly to apply a DC high voltage to the insulator;

[0026] After the pressurization is completed, the external voltage is first removed, the driving structure is controlled to drive the electrostatic probe to move to a specified position, and the second central high-voltage conductor component is controlled by the first driving component to drive the insulator to move to a specified position;

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

[0028]

[0029] Wherein, D is the side length of the square bottom surface of the electrostatic probe, L is the diameter of the insulator, and x is the step length of the electrostatic probe scanning path in the horizontal direction;

[0030] After the electrostatic probe completes scanning of the surface potential of the insulator, the insulating gas is discharged out of the cavity.

[0031] Compared with the prior art, the insulator surface potential measuring device and measuring method according to the embodiment of the present invention have the following beneficial effects:

[0032] The second central high-voltage conductor assembly of the embodiment of the present invention is used to install the insulator, while the first central high-voltage conductor assembly is connected to the high-voltage wiring assembly, together constituting the core part of the 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 so that it can be connected with the first central high-voltage conductor assembly under driving, and the electrostatic probe is controlled by the driving structure to scan the surface of the insulator to achieve accurate measurement of the surface potential of the insulator, which solves the limitations of the prior art in measuring the surface potential of insulators with complex geometric shapes, and through the above control, the measurement efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0037] Figure 5 It is a structural schematic diagram of a second central high-voltage conductor assembly, a first drive assembly, and a second drive assembly provided by an embodiment of the present invention;

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

[0039] Figure 7Schematic diagram of the scanning trajectory of the electrostatic probe of the insulator surface potential measuring device provided by an embodiment of the present invention;

[0040] In the figure, 1, housing; 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 frame; 422, horizontal drive unit; 4221, second drive member; 4222, second screw; 4223, second slider; 423, vertical drive unit; 4231, first drive Component; 4232, first screw; 4233, first slider; 5, first center high-voltage conductor assembly; 51, first center high-voltage conductor; 52, first grounding sleeve; 6, second center high-voltage conductor assembly; 61, second center 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, mobile platform. DETAILED DESCRIPTION

[0041] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present 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 housing 1 has a sealed cavity, an air inlet for filling insulating gas and an exhaust port 14 for discharging insulating gas, and the cavity is connected with the air inlet and the exhaust port 14; the high-voltage wiring assembly 2 is installed in the housing 1, and one end of the high-voltage wiring assembly 2 extends into the cavity, and the other end of the high-voltage wiring assembly 2 is externally connected to a high-voltage power supply; one end of the vacuum assembly 3 passes through the housing 1 and extends into the cavity to perform a vacuum operation on the cavity; the electrostatic probe assembly 4 includes an electrostatic probe 41 and a driving structure 42, the electrostatic probe 41 and the driving structure 42 are installed in the cavity, and the electrostatic probe 41 is connected to the driving structure 42 to scan the surface of the insulator through the driving structure 42; the first central high-voltage conductor assembly 5 is arranged in the cavity and connected to one end of the high-voltage wiring assembly 2; the second central high-voltage conductor assembly 6 is arranged in the cavity and arranged opposite to the first central high-voltage conductor assembly 5, and the second central high-voltage conductor assembly 6 faces one end of the first central high-voltage conductor assembly 5 for installing the insulator; the second central high-voltage conductor 61 is installed in the first driving assembly 7 to be connected with the first central high-voltage conductor assembly 5 under the drive of the first driving assembly 7.

[0043] The sealed cavity of this embodiment is used to simulate the actual working environment, and the air inlet and exhaust port 14 thereon ensure that insulating gases such as C4F7N, CO2, SF6, N2, CF3I and compressed air can be filled and discharged, thereby creating a closed test environment isolated from the outside world. The high-voltage wiring assembly 2 is used to connect an external high-voltage power supply, one end of which extends into the cavity to provide the necessary voltage conditions for the test. In addition, the cavity can be evacuated through the vacuum assembly 3, which helps to remove impurities or air that may exist in the cavity, ensure the purity of the test environment, and reduce 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, and the first central high-voltage conductor assembly 5 is connected to the high-voltage wiring assembly 2, together constituting the core part of the 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, and the electrostatic probe 41 is controlled by the driving structure 42 to scan the surface of the insulator to achieve accurate measurement of the surface potential of the insulator, which solves the limitations of the prior art in measuring the surface potential of insulators with complex geometric shapes, and through the above control, the measurement efficiency is improved.

[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 outer shell 1. One end of the high-voltage electrode conductor 22 is passed through the high-voltage bushing 21 and extends into the cavity, so as to realize electrical isolation between the high-voltage electrode conductor 22 and the cavity through the high-voltage bushing 21, ensuring that even under high-voltage conditions, the current can be effectively prevented from flowing directly through the outer shell 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, providing 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 the oil-gas separator 32 is arranged between the vacuum pump 31 and the outer shell 1 . The first ball valve 33 is arranged between the oil-gas separator 32 and the outer shell 1 .

[0047] In this embodiment, the vacuum pump 31 is mainly used to extract the gas in the cavity to achieve the purpose of creating a low-pressure environment. At the same time, the oil-gas separator 32 ensures that the gas is extracted while separating and recycling the vacuum pump 31 oil, preventing the oil mist from polluting the internal environment of the cavity, maintaining the internal cleanliness, and also preventing the oil mist from being discharged into the external environment to cause environmental pollution. In addition, 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 air pressure in the cavity.

[0048] It should be noted that, in the present embodiment, the cavity is further 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, wherein the first air inlet 12 and the second air inlet 13 both include an air supply source and an air valve, the air supply source is connected to the cavity via a pipeline, and the air valve is installed on the air supply pipeline for controlling 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 driving structure 42 includes a mounting frame 421, a horizontal driving unit 422 and a vertical driving unit 423. The vertical driving unit 423 is mounted on the mounting frame 421. The horizontal driving unit 422 is connected to the vertical driving unit 423. The electrostatic probe 41 is mounted on the horizontal driving unit 422 and is responsible for moving the electrostatic probe 41 in the horizontal direction (usually the X-axis or the Y-axis). By accurately controlling the horizontal displacement, the potential measurement of different areas on the surface of the insulator can be achieved. The vertical driving unit 423 cooperates with the horizontal driving unit 422 and is responsible for controlling the movement of the electrostatic probe 41 in the vertical direction (usually the Z-axis).

[0050] In this embodiment, the horizontal driving unit 422 and the vertical driving unit 423 work together to achieve accurate positioning of the electrostatic probe 41 in three-dimensional space, ensuring the accuracy of the selection of the measurement point and the moving path. In addition, through the preset program control, a series of measurement tasks can be automatically completed, avoiding the errors that may be caused by manual operation, and reducing the workload of the experimenter. The bracket 63 is made of polytetrafluoroethylene, and the electrostatic probe 41 is led out from the inside of the cavity through the lead flange and then connected 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 installed on the mounting frame 421, the output shaft of the first drive member 4231 is connected to the first screw 4232, and the first slider 4233 is installed on the first screw 4232; the first drive member 4231 of this embodiment is a motor, which is responsible for providing power. It is connected to the first screw 4232 through its output shaft to convert 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, thereby realizing movement in the vertical direction. 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 positioning of the electrostatic probe 41 in the vertical direction.

[0052] The horizontal driving unit 422 includes a second driving member 4221, a second screw 4222 and a second slider 4223. The second driving member 4221 is mounted on the first slider 4233, and the second screw 4222 is connected to the output shaft of the second driving 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. It can be understood that the second driving member 4221 of this embodiment is also a motor, which is mounted on the first slider 4233 to ensure that the horizontal driving unit 422 can move in the vertical direction with the first slider 4233. When the second driving member 4221 rotates, the second screw 4222 rotates, and the second slider 4223 moves linearly along the screw to achieve horizontal movement. By controlling the rotation of the second driving member 4221, the position of the electrostatic probe 41 in the horizontal direction can be accurately controlled in this embodiment. Combined with the movement in the vertical direction, the electrostatic probe 41 can be accurately positioned in three-dimensional space, which can improve 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 on the circumference 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 it after receiving the voltage of the high-voltage power supply. By adjusting the applied voltage, the intensity and distribution of the electric field can be controlled to provide the necessary electric field environment for measuring the change in the surface potential of the insulator. The first grounding sleeve 52 is connected to the earth through the grounding electrode lead, which can timely discharge the static electricity or fault current that may be generated, further ensuring the safety of the experimenters 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 bracket 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 bracket 63, ensuring its stable position in the experiment. The second grounding sleeve 62 is arranged on the circumferential side 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 timely discharge static electricity or fault current that may be generated, further ensuring the safety of experimental personnel and equipment, and through the spacing design between the second grounding sleeve 62 and the second central high-voltage conductor 61, it also plays the role of electrical isolation, protecting the experimenters from the risk of accidental electric shock.

[0058] It should be noted that the second grounding sleeve 62 is a cylindrical barrel, the axis of which coincides with the second central high-voltage conductor 61 , wherein the first central high-voltage conductor 51 and the second central high-voltage conductor 61 are preferably in 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 installed on the first slide rail 72, and the third slider 74 is connected to the third screw 73. The second center high-voltage conductor 61 is installed on the third slider 74.

[0060] The third driving member 71 of this embodiment serves as the power source of the first driving assembly 7, and can be a motor or a servo motor, which is used to provide power for linear or rotational motion. The first slide rail 72 provides a track for linear motion for the third slider 74, ensuring that it slides smoothly on a predetermined path, which is the basis for achieving precise positioning and stable motion. In addition, through the interaction between the thread and the third slider 74, the rotational motion of the third driving member 71 is converted into linear motion, achieving precise displacement of the third slider 74 on the first slide rail 72, and driving the second central high-voltage conductor 61 to move in the experimental space.

[0061] Furthermore, it also includes a second drive component 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 installed on the second slide rail 82, and the fourth slider 84 is connected to the fourth screw 83, and the first drive component 7 is installed on the fourth slider 84.

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

[0063] Furthermore, the cavity is provided with three observation windows for observing the movement of the insulator inside the cavity. In addition, a resistance vacuum gauge, a safety valve and an air pressure sensor are also provided in the cavity, wherein the resistance vacuum gauge is used to detect the vacuum degree of the cavity during the vacuuming process, the air pressure sensor is used to measure the air pressure of the insulating gas rushing into the cavity, and the safety valve is used to control the air pressure of the cavity to prevent overpressure.

[0064] In this embodiment, a control display component is also included, which is respectively connected to the resistance vacuum gauge, the air 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.

[0065] In addition, it also includes a base 9 and a mobile platform 10. The shell 1 and the mobile platform 10 are both installed on the base 9, and the mobile platform 10 is located in the cavity and connected to the base 9 through a guide rail. The shell is provided with a switch door for the mobile platform 10 to slide out of the cavity or slide into the cavity. The second drive component 8, the first central high-voltage conductor component 5 and the drive structure 42 are all installed 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, which is applied to the above-mentioned device for measuring the surface potential of an insulator. The method for measuring the surface potential of an insulator comprises the following steps:

[0067] S110, exhausting the air in the cavity until the cavity is in a vacuum state;

[0068] Before this step, it is necessary to connect the pressure circuit, and the DC voltage source with an output voltage of 0 to ±100 kV is connected to the high-voltage electrode conductor 22 of the cavity through a protective resistor. Before the experiment, the insulator sample is scrubbed with anhydrous ethanol and dried in an oven for 10 hours to remove the residual parasitic charge on the surface of the insulator. Then, the switch door of the cavity is opened, the mobile platform 10 is moved outside the cavity, the insulator is installed on the second center high-voltage conductor 61, the mobile platform 10 is moved into the cavity, and the switch door of the cavity is closed.

[0069] Subsequently, the vacuum pump 31 and the first ball valve 33 are opened to exhaust the air in the cavity, and when the cavity reaches a vacuum state, the first ball valve 33 and the vacuum pump 31 are closed.

[0070] S120, injecting insulating gas into the cavity, and stopping inflation when the air pressure in the cavity meets the requirement;

[0071] Open the air valve of the first air inlet 12 or the second air inlet 13 and the second ball valve 11 to inject insulating gases such as C4F7N, CO2, SF6, N2, CF3I and compressed air into the cavity, stop charging when the air pressure meets the requirement, 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, moving the electrostatic probe 41 to a specified position through the driving structure 42, and controlling the second central high-voltage conductor assembly 6 to connect with the first central high-voltage conductor assembly 5 through the first driving assembly 7, so as to apply a 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 drive the electrostatic probe 41, the insulator and the second grounding sleeve 62 to move 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 connectivity with the high-voltage electrode conductor 22, and the insulator outer insert is fitted 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 a DC high voltage is applied to the insulator through the central high-voltage conductor; at the same time, the electrostatic probe 41 is kept away from the coaxial cylindrical electrode structure.

[0074] S140, after the pressurization is completed, the external voltage is removed first, the driving structure 42 is controlled to drive the electrostatic probe 41 to move to the specified position, and the second central high-voltage conductor component 6 is controlled by the first driving component 7 to drive the insulator to move to the specified 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 measuring 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 to make the insulator suspended, and 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, the electrostatic probe 41 then scans the surface of the insulator, and the step length of the scanning path of the electrostatic probe 41 in the horizontal direction satisfies the following formula:

[0077]

[0078] Among them, D is the side length of the square bottom surface of the electrostatic probe 41, L is the diameter of the insulator, and x is the step length 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, I≤D / 2.

[0079] The end face of the electrostatic probe 41 of this embodiment 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, the scanning time required by the electrostatic probe 41 will increase, reducing efficiency; if the scanning path is too sparse, the scanning path of the electrostatic probe 41 will not cover the entire insulator, and the test result will not reflect the surface potential distribution of the entire insulator.

[0080] It should be noted that the distance between the scanning track 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] Where: D is the side length of the square bottom of the electrostatic probe, and d is the vertical distance between the center point of the electrostatic probe and the surface of the insulator. The electrostatic probe 41 is a Kelvin oscillation active electrostatic probe, which can measure the potential and potential distribution on the surface of the insulator without contacting the surface of the test object.

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

[0086] It should be noted that in order to adapt to the requirements of various working conditions, the surfaces of insulators in the GIL / GIS system are mostly irregular shapes composed of inclined surfaces and curved surfaces. Through the mutual 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 of various complex shapes, and can achieve a higher efficiency of insulator surface potential measurement, thereby avoiding the problem of decreased measurement accuracy caused by attenuation of the insulator surface potential due to long measurement time.

[0087] In summary, the embodiment of the present invention provides an insulator surface potential measuring device and method, which can realize the movement of the electrostatic probe 41 in the front-back and up-down directions through the cooperation of the horizontal driving unit 422 and the vertical driving unit 423, and cooperate with the first driving component 7 to move the insulator in the left-right direction, so that the electrostatic probe 41 can scan the entire insulator surface without being restricted by the geometric shape of the insulator. The measurement method is simple to operate, easy to use, and has a high degree of automation. The above device can simulate the actual operating environment in the GIL / GIS system, including actual operating conditions such as high-pressure insulating gas atmosphere and coaxial cylindrical electrode structure.

[0088] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An insulator surface potential measuring device, characterized in that: include The housing has a sealed cavity, an air inlet for filling with insulating gas, and an exhaust port for exhausting the insulating gas, wherein the cavity is in communication with the air inlet and the exhaust port; A high-voltage wiring assembly is installed in the housing, and one end of the high-voltage wiring assembly extends into the cavity, and the other end of the high-voltage wiring assembly is externally connected to a high-voltage power supply; A vacuum assembly, one end of which passes through the housing and extends into the cavity to perform a vacuum operation on the cavity; An electrostatic probe assembly, comprising 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 the insulator through the driving structure; A first central high-voltage conductor assembly is 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, wherein an end of the second central high-voltage conductor assembly facing the first central high-voltage conductor assembly is used for mounting an insulator; and A first driving component, wherein the second central high-voltage conductor is installed on the first driving component to be connected with the first central high-voltage conductor component under the drive of the first driving component.

2. The insulator surface potential measuring device according to claim 1, characterized in that: The high-voltage wiring assembly includes a high-voltage bushing and a high-voltage electrode conductor. The high-voltage bushing is installed on the shell. One end of the high-voltage electrode conductor is passed through the high-voltage bushing and extends into the cavity. The other end of the high-voltage electrode conductor is externally connected to a high-voltage power supply.

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

4. The insulator surface potential measuring device according to claim 1, characterized in that: The driving structure comprises a mounting frame, a horizontal driving unit and a vertical driving unit. The vertical driving unit is mounted on the mounting frame. The horizontal driving unit is connected to the vertical driving unit. The electrostatic probe is mounted on the horizontal driving unit.

5. The insulator surface potential measuring device according to claim 4, characterized in that: The vertical driving unit comprises a first driving member, a first screw rod and a first slider, wherein the first driving member and the first screw rod are mounted on the mounting frame, the output shaft of the first driving member is connected to the first screw rod, and the first slider is mounted on the first screw rod; The horizontal driving unit includes a second driving member, a second screw and a second slider. The second driving member is installed on the first slider, and the second screw is connected to the output shaft of the second driving member. The second slider is installed on the second screw, and the electrostatic probe is installed on the second slider.

6. The insulator surface potential measuring device according to claim 1, characterized in that: 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 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.

7. The insulator surface potential measuring device according to claim 1, characterized in that: The second central high-voltage conductor assembly includes a second central high-voltage conductor, a second grounding sleeve and a bracket. The end of the second central high-voltage conductor facing away from the first central high-voltage conductor assembly is connected to the bracket. The second grounding sleeve is arranged on the circumference of the second central high-voltage conductor, and there is a gap between the second grounding sleeve and the second central high-voltage conductor.

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

9. The insulator surface potential measuring device according to claim 8, characterized in that: It also includes a second drive component, which includes a fourth drive member, a second slide rail, a fourth screw rod and a fourth slider, the fourth drive member is connected to the fourth screw rod, the fourth slider is slidably installed on the second slide rail, and the fourth slider is connected to the fourth screw rod, and the first drive component is installed on the fourth slider.

10. A method for measuring the surface potential of an insulator, characterized in that: Applied to the insulator surface potential measuring device as claimed in any one of claims 1 to 9, the insulator surface potential measuring method comprises the following steps: Exhausting the air from the cavity until the cavity is in a vacuum state; Insulating gas is injected into the cavity, and inflation is stopped when the gas pressure in the cavity meets the requirement; Move the electrostatic probe to a specified position through the driving structure, and control the second central high-voltage conductor assembly to be connected to the first central high-voltage conductor assembly through the first driving assembly to apply a DC high voltage to the insulator; After the pressurization is completed, the external voltage is first removed, the driving structure is controlled to drive the electrostatic probe to move to a specified position, and the second central high-voltage conductor component is controlled by the first driving component to drive the insulator to move to a specified position; Then, the electrostatic probe scans the surface of the insulator, and the step length of the electrostatic probe scanning path in the horizontal direction satisfies the following formula: x=D,L>100D Wherein, D is the side length of the square bottom surface of the electrostatic probe, L is the diameter of the insulator, and x is the step length of the electrostatic probe scanning path in the horizontal direction; After the electrostatic probe completes scanning of the surface potential of the insulator, the insulating gas is discharged out of the cavity.

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