Visual quantitative measurement and analysis device and method for detecting surface discharge degree of insulating material

Abstract

The invention discloses a visual quantitative measurement and analysis device and method for detecting the surface discharge degree of an insulating material, and relates to the field of visual quantitative detection of the surface discharge degree of the insulating material. By constructing an electrostatic discharge system, the pulse discharge process of the insulating surface under the actual operation condition is simulated, and then the surface of the insulating material is induced to discharge. A visual processing device is built, through the polarization effect between dust and charges, the surface charge distribution condition is rapidly reproduced through the dust, and equipment recording is shot. A gray-scale map working principle is applied, a gray-scale conversion and binarization processing program is written, the program is started to convert a recorded picture into a binary image only containing black and white pixel points, the number of the pixel points is counted, and the charge distribution density in an effective discharge radius is calculated through formula conversion, so that the electrostatic discharge degree is quantitatively represented. By changing environmental conditions such as humidity and air pressure, service life state evaluation of the insulation equipment and insulation detection and structure optimization work of the novel insulation equipment in a complex environment are researched.

Description

Technical Field

[0001] The present invention relates to the field of insulating material surface charge detection, and in particular to a visual quantitative measurement and analysis device and method for insulating material surface discharge degree detection. Background Art

[0002] With the major breakthroughs in my country's UHV transmission technology and the surge in electricity consumption across the country, the insulation performance of important insulation links in the power transmission and transformation system, such as pot insulators, porcelain bottles, wall bushings and other high-voltage equipment widely used in smart substations, has been greatly tested. However, due to the invisible tiny defects on the insulation surface and the metal particles in the environment, they will induce the formation of charge clusters on the surface, thereby generating discharge channels and causing insulation failure.

[0003] At present, the mainstream research idea at home and abroad is still to study the insulation failure mechanism of the gas-solid interface under high voltage through surface charge observation, such as the electrostatic probe method, the Pockels effect method and the dust map method.

[0004] Among them, the electrostatic probe method requires the inversion calculation of the surface potential distribution to obtain the surface charge distribution, so there is a certain error, and the Pockels effect method requires the construction of a complete optical reflection system, which is expensive and technically complex and cannot be promoted and applied on a large scale.

[0005] The dust image method is a simple and fast method for characterizing charge and has been used to this day. However, although the dust image method can visualize the charge, it cannot quantitatively characterize the degree of discharge. Summary of the invention

[0006] The purpose of the present invention is to address the above defects and invent a visual quantitative measurement and analysis device and method for detecting the surface discharge degree of insulating materials, which can combine dust maps and image recognition technology to achieve rapid visualization of insulation surface charge characterization detection and quantitative description of the discharge degree.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions:

[0008] A visual quantitative measurement and analysis device for detecting the discharge degree of the surface of an insulating material, comprising a discharge simulation device, a charge visualization processing device and a complex environment simulation device;

[0009] The discharge simulation device comprises an ESD gun, a discharge electrode, a ground electrode, an insulating material, a closed container, a high-voltage probe and an oscilloscope;

[0010] The sealed container is a rectangular parallelepiped; the discharge electrode 1 is arranged in the sealed container, and is connected to the ESD gun 1 through one end of a copper rod extending out of the container; the high-voltage probe is connected to the copper rod outside the container through a soft copper wire with an insulating skin; the high-voltage probe transmits the collected discharge pulse waveform to the oscilloscope, and records the discharge waveform in real time;

[0011] The insulating material is horizontally placed on the ground electrode 1;

[0012] The ground electrode in the container is connected to the earth through a soft copper wire;

[0013] The charge visualization processing device comprises a PMMA sealed container, an insulating fixture, insulating material, a fan and dust;

[0014] The PMMA sealed container is a rectangular parallelepiped; the insulating fixture is annular in shape and made of epoxy resin, and is fixed to the bottom plate of the sealed container by a bracket, and the insulating material is vertically suspended in the center of the PMMA sealed container; the insulating material is PMMA; the fan is fixed to the bottom plates at the four corners of the PMMA sealed container by a bracket, and is controlled by an external power supply, and glass containers are placed under the fan to hold dust;

[0015] The charge visualization processing device comprises a PMMA sealed container, an insulating fixture, insulating material, a fan and dust;

[0016] The discharge generator comprises two ESD guns, two discharge electrodes, two ground electrodes, and insulating materials; the humidifier has remote control and timing functions, and is placed in a corner inside the vacuum barrel. The temperature and humidity meter can display the ambient temperature and humidity in real time; the vacuum barrel is a stainless steel barrel, which is equipped with a cover plate made of PMMA material. A hole is opened on the plate to allow the two discharge electrodes in the closed container to pass through. The end of the two discharge electrodes extending outside the vacuum barrel is connected to the two external ESD guns; the two ground electrodes in the container are connected to the earth through a soft copper wire; a through hole is opened on the wall of the vacuum barrel, and a connecting pipe at one end of the pressure valve is placed in the container. The pressure valve is provided with a pressure gauge, and the connecting pipe at the other end of the pressure valve is connected to a vacuum pump, and the vacuum pump is controlled to start and stop by an external power supply; the internal pressure of the vacuum barrel can be displayed in real time through the pressure gauge matching the pressure valve.

[0017] Furthermore, the insulating material has a plane size of 12*12 cm and a thickness of 4 mm.

[0018] Furthermore, the material of the sealed container is customized using a transparent PMMA plate with a size of 100*80*60 cm, which is convenient for observing the visual processing process.

[0019] Furthermore, the discharge electrode 1, discharge electrode 2, ground electrode 1 and ground electrode 2 are all spherical copper electrodes, the diameters of the discharge electrodes 1 and 2 are 2-4 cm, and the diameters of the copper discharge electrode 1 and ground electrode 2 are 6-10 cm.

[0020] Furthermore, the four sets of fans are fixed directly above the dust through height-adjustable stainless steel brackets, and a glass container is placed under each fan for holding 10 ml of dust.

[0021] Furthermore, the dust is pink printer toner, which is spherical in shape and has a particle size of 5-100 μm.

[0022] A method for quantitative analysis using the visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material, the method steps are as follows:

[0023] S1. Before testing, assemble the discharge simulation device, charge visualization processing device and complex environment simulation device;

[0024] Wipe the insulating material sample with alcohol and dry it;

[0025] grounding a ground electrode 1 and testing the ground electrode 1;

[0026] Fix the measuring wire on the discharge electrode, connect the high-voltage probe, adjust, measure and record the charging and discharging voltage of the ESD gun, and connect the output end of the high-voltage probe to the oscilloscope;

[0027] Accurately debug the external mobile power supply with timing function and connect it to the fan with adjustable air volume;

[0028] Link debugging of various devices;

[0029] Place 10ml of dust at the four corners of the capacitor;

[0030] S2. Testing:

[0031] The discharge is triggered by using an electrostatic discharge simulation device. Pulling the trigger of the ESD gun triggers the discharge, causing the copper discharge electrode tip to generate a high-voltage pulse, which breaks through the air for discharge, triggering discharge at the gas-solid interface, ionizing the air near the discharge electrode, and attaching positive charges to the surface of the insulating material. With the distortion of the local electric field, the discharge is further induced, spreading around with the discharge electrode as the core, forming a "sea urchin"-shaped discharge tree cluster.

[0032] Use the charge visualization processing device to visualize the discharged charge, quickly remove the ESD gun, and fully discharge it before removing it to avoid residual charge contacting the surface of the insulating material and causing secondary discharge; transfer the sample to the visualization device, start the fan to blow air for several seconds, so that the dust is evenly distributed in the discharge container; wait for the dust to be adsorbed, and after all the unadsorbed dust settles to the bottom of the container and stabilizes, open the container, blow away the excess dust on the surface of the insulating material, leave the dust pattern, and take a photo to record the dust pattern;

[0033] Processing of binary images, identifying and marking the effective discharge radius, setting the length of the single longest electrical tree branch as the effective discharge radius, cutting and retaining the effective discharge area;

[0034] The image recognition device is activated to accurately identify the area where the pink toner is attached and flip its color to white, while the rest of the area is black;

[0035] Track the image segmentation area, process the image into a binary image, use the program to count the number of white pixels and black pixels in the image, calculate the proportion of white pixels in the effective discharge space, and quantitatively characterize the intensity of this discharge;

[0036] The calculation method first uses the classic Luminance algorithm to convert the pixels in the image between 0-255 to achieve grayscale conversion. The calculation formula is as follows:

[0037] Gray(x,y)=0.299R(x,y)+0.587G(x,y)+0.114B(x,y)

[0038] Where: R is the pixel value of the red channel, G is the pixel value of the green channel, B is the pixel value of the blue channel, and Gray is the grayscale value;

[0039] Based on the above algorithm principle, the grayscale image is binarized. The principle is: by setting the critical grayscale value, hereinafter referred to as the threshold, the grayscale value greater than the threshold is set to the maximum grayscale value "255" to represent black, and the grayscale value less than the threshold is set to the minimum grayscale value "0" to represent white, so that the overall image appears in black and white. The main program running logic is as follows:

[0040] Define the name of the desktop dust image, write access code, access the defined desktop image, read it into the main program, perform grayscale conversion and binarization processing, and count the number of black and white pixels through the program; adjust the threshold according to the result until the shape of the electrical tree in the image before and after processing is highly consistent; write output code, output the converted binary image and pixel statistics results, and save them to the desktop;

[0041] In order to quantitatively describe the results output by the above program, the circle formed by the outer diameter of the longest electrical tree channel is the "effective discharge circumference", and the area ratio of the electrical tree within the effective discharge circumference is the "surface charge density". The "surface charge density" is introduced to quantitatively describe the development degree of the positive polarity electrical tree;

[0042] Calculate the number of pixels in the square image through the binarized histogram: Let the number of black pixels be A and the number of white pixels be B, then the diameter of the effective discharge circle is (A+B) 1 / 2 The total number of pixels contained in the effective discharge circle is π(A+B) 2 / 4, the number of white pixels is divided by the total number of pixels in the circle, and the surface charge density is obtained as 4B(A+B) -2 / π;

[0043] S3. According to the measurement method described in S2, a complex environment simulation device is used to carry out electrostatic discharge tests under special environmental conditions of high humidity and low pressure, and the insulation failure mechanism in rainy weather and high altitude areas is studied respectively; the test adopts the control single variable method, and the single variables are relative humidity and atmospheric pressure;

[0044] First, the single variable "relative humidity" is changed, and the relative humidity is selected as 20% RH and 90% RH, and the discharge temperature is kept at 20°C and the atmospheric pressure is kept at 100 kPa.

[0045] By building a complex environmental simulation program, the start and stop of the humidifier is controlled to change the relative humidity of the discharge environment. To ensure the stability of the environmental humidity, the start and stop control is repeated; when the environmental humidity reaches the set value, it is maintained for a few seconds, and after waiting for a few minutes, the humidifier is started again, and the start and stop control is repeated; after the discharge is completed, the sample is quickly transferred and placed in the visualization processing system for visualization processing;

[0046] Secondly, the single variable "atmospheric pressure" was changed, and the atmospheric pressure was selected to be 100 kPa, 80 kPa and 60 kPa, and the discharge temperature was kept at 20°C and the relative humidity was kept at 20% RH.

[0047] By building a low-pressure system and adopting a repetitive control method, the air pressure in the vacuum barrel is displayed in real time through a pressure gauge that matches the pressure valve. When the air pressure reaches the set value, it is maintained for a few seconds, the valve is closed, the vacuum pump is stopped, and after waiting for tens of seconds, the vacuum pump is started again. This operation is repeated many times. After the discharge is completed, the pressure in the barrel needs to be quickly restored to the standard atmospheric pressure, and the sample must be quickly transferred to the visualization system for processing.

[0048] Furthermore, the duration of starting the fan to supply air in step S1 is 10 seconds.

[0049] Furthermore, the closed container in step S3 is a stainless steel vacuum barrel, an observation window is provided on the barrel body, the observation window panel is made of an acrylic plate, a hole is opened on the observation window and sealed; the discharge electrode is placed in the container, the pressure valve is connected to the pipe in the container, and the other end is connected to the vacuum pump, and the start and stop of the equipment is controlled by an external power supply.

[0050] Furthermore, in step S3, the air pressure is maintained for 10 seconds, the waiting time is 1 minute, and the start-stop control is repeated 5 times.

[0051] How it works

[0052] This patent constructs an electrostatic discharge system to simulate the pulse discharge process on the insulating surface under actual operation conditions, thereby inducing surface discharge of insulating materials. On this basis, a visualization processing device is built to quickly reproduce the surface charge distribution using dust through the polarization effect between dust and charge, and record it using shooting equipment. Applying the working principle of grayscale images, a grayscale conversion and binarization processing program is written. The program is started to convert the recorded image into a binary image containing only black and white pixels and count the number of pixels. The charge distribution density within the effective discharge radius is calculated through formula conversion, thereby quantitatively characterizing the degree of this electrostatic discharge.

[0053] Beneficial Effects

[0054] The method of the present invention can achieve rapid response of the charge distribution on the surface of the insulating material, thereby achieving rapid reproduction of the charge on the surface of the insulating material.

[0055] The discharge channels along the surface of the insulating material can be quickly visualized according to the dust map, and the characteristic quantities can be extracted by combining image processing technology to quantitatively characterize the degree of discharge. By providing a visualization rapid response and quantitative analysis method of discharge characteristic values, it is used for quantitative analysis of the influence of complex environment on the discharge on the insulation surface. The influence mechanism of different discharge environments on the surface charge distribution of the insulating material is studied, which provides a way of thinking for the optimal design of the insulation structure and the evaluation of insulation aging and failure mechanism. It is of great significance to extend the service life of the insulation equipment in the substation.

[0056] By changing environmental conditions such as humidity and air pressure, we study the life status evaluation of insulation equipment in complex environments and the insulation detection and structural optimization of new insulation equipment. This is of great significance for fault analysis of insulation equipment such as pot insulators and wall bushings in substations. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Electrostatic discharge simulation device diagram;

[0058] Figure 2 Visual processing device diagram;

[0059] Figure 3 Complex environment simulation device;

[0060] Figure 4 Dust particle size distribution and microscopic morphology;

[0061] Figure 5 Grayscale conversion and binarization processing source code diagram;

[0062] Figure 6 Binary images of electrical tree branches at different humidity levels;

[0063] Figure 7 Binary diagram of electrical tree under different gas pressures;

[0064] Figure 8 Comparison of grayscale conversion and binarization before and after processing

[0065] In the figure: 1-1, ESD gun one; 1-2, discharge electrode one; 1-3, ground electrode one; 1-4, insulating material; 1-5, sealed container; 1-6, high-voltage probe; 1-7, oscilloscope; 2-1, PMMA sealed container; 2-2, insulating clamp; 2-3, fan; 2-4, dust; 3-1, humidifier; 3-2, temperature and humidity meter; 3-3, vacuum barrel; 3-4, vacuum pump; 3-5, pressure valve; 3-6, ESD gun two; 3-7, ground electrode two; 3-8, discharge electrode two. DETAILED DESCRIPTION

[0066] The following will be combined with the appended Figure 1-8 , clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] See also Figure 1 , is a schematic diagram of an insulating material surface electrostatic discharge simulation device provided by an embodiment of the present invention, the electrostatic discharge simulation device includes: an ESD gun 1-1, a discharge electrode 1-2, a ground electrode 1-3, an insulating material 1-4, a sealed container 1-5, a high-voltage probe 1-6 and an oscilloscope 1-7.

[0068] The ESD electrostatic discharge gun 1-1 model is SCHLODER SESD-200, and its discharge amplitude is adjustable from 0 to ±20 kV.

[0069] Preferably, the ESD electrostatic discharge gun 1-1 pulse parameters are as follows: peak value is +5.4kV, pulse width is about 300ms, and rise time is about 37ms.

[0070] The insulating materials 1-4 are made of polymethyl methacrylate (PMMA), which has a relative dielectric constant of 3.2 and a surface resistivity of >10 12 Ω, thickness is 4mm, side length is 12*12cm.

[0071] The discharge electrode 1-2 is a spherical electrode with a diameter of 2 cm, connected to the ESD gun 1-1 through a copper rod, and a soft copper wire with an insulating skin is connected to the copper rod, which is connected to the high-voltage probe 1-6. When the discharge is triggered, the high-voltage probe 1-6 transmits the collected discharge pulse waveform to the oscilloscope 1-7 to record the discharge waveform in real time. The ground electrode 1-3 is a copper electrode, the size of a circle with a diameter of 8 cm, and is connected to the ground through a soft copper wire.

[0072] See also Figure 2 , is a schematic diagram of a charge visualization processing device, which consists of the following parts: a PMMA sealed container 2-1, an insulating fixture 2-2, an insulating material 1-4, a fan 2-3 and dust 2-4; in order to facilitate the observation of the visualization processing process, the cover material of the sealed container 2-1 is customized with a transparent PMMA plate with a size of 100*80*60cm.

[0073] The insulating clamp 2-2 is made of epoxy resin, and the insulating material 1-4 is fixed in the center of the sealed container 2-1 by adjusting the screws. It should be noted that this process must be completed quickly and the charge attachment area in the middle of the insulating material 1-4 must not be touched.

[0074] The four sets of fans 2-3 are located at the four corners of the closed container 2-1 and are fixed directly above the dust 2-4 by height-adjustable stainless steel brackets, and glass containers are placed below each of them for placing 10 ml of dust 2-4.

[0075] The dust 2-4 is pink printer toner, and its microscopic morphology and particle size distribution results are shown in Figure 4 , its shape is spherical and its particle size is 5-100μm.

[0076] See also Figure 5 , is a grayscale conversion and binarization image processing program. By inputting the file path and setting the binarization threshold, the program automatically accesses the target file, reads the image, calls the grayscale conversion and binarization algorithm to process it, and can accurately convert the image into an image with binary features, and count the number of black and white pixels in the image, and display it in the form of a histogram. Then the program outputs the processed image and saves it in the specified folder.

[0077] See also Figure 3, is a schematic diagram of a complex environment simulation device, which consists of the following parts: a humidifier 3-1, a temperature and humidity meter 3-2, a vacuum barrel 3-3, a vacuum pump 3-4, a pressure valve 3-5, an ESD gun 3-6, a ground electrode 3-7, and a discharge electrode 3-8.

[0078] The discharge electrode 3-8 of the discharge generator is a spherical electrode with a diameter of 2 cm, which is connected to the ESD gun 1 3-6 through a copper rod. The ground electrode 3-7 is a copper electrode with a size of a circle with a diameter of 8 cm, which is connected to the ground through a soft copper wire. The ESD gun 2 3-6 triggers discharge through the discharge electrode 3-8.

[0079] The humidity control device is composed of a humidifier 3-1 and a temperature and humidity meter 3-2, wherein the humidifier 3-1 can be started and stopped by remote control and has a timing function, and the temperature and humidity meter 3-2 can display the current temperature and relative humidity in real time.

[0080] The air pressure control device is composed of a vacuum barrel 3-3, a vacuum pump 3-4, and a pressure valve 3-5 (equipped with a pressure gauge). The cover of the vacuum barrel 3-3 is made of PMMA and is set as an observation window to facilitate observation of the situation inside the barrel. The vacuum pump 3-4 can reduce the air pressure to 50kPa at the lowest. The pressure gauge can display the current pressure in the barrel in real time. At the same time, it is equipped with a valve, and the input of the vacuum pump 3-4 can be manually controlled.

[0081] The test results under different humidity conditions are shown in Figure 6 , is the binary diagram of electric tree under the action of +5.4kV ball electrode at different humidity. Table 1 is the surface charge density calculated by image processing technology under this condition. The data show that when the relative humidity is 20%RH, the surface charge density is 44.68%, and when the relative humidity increases to 90%RH, the surface charge density drops to 24.07%. It can be seen that the high humidity environment affects the discharge process of the insulating surface and has a certain degree of inhibitory effect on it.

[0082] Table 1 Surface charge density at different humidity

[0083]

[0084] join Figure 7 , is the binary diagram of electric tree under the action of +5.4kV ball electrode at different gas pressures. Table 2 shows the corresponding surface charge density. When the gas pressure is 100kPa, the surface charge density is 35.84%. When the gas pressure is reduced to 80kPa, the surface charge density increases by 42.03%. When the gas pressure continues to decrease to 60kPa, the surface charge density reaches 50.95%, indicating that the discharge degree of the insulating surface is enhanced at low gas pressure, and the lower the gas pressure, the more nonlinear the enhancement degree.

[0085] See also Figure 8Figure a is the dust image before grayscale conversion and binarization, and Figure b is the dust image after grayscale conversion and binarization. It can be seen that the program can perfectly reproduce the distribution of dust 2-4.

[0086] Table 2 Surface charge density at different pressures

[0087]

[0088] The discharge gun 1-1, humidifier 3-1, vacuum pump 3-4, pressure valve (with pressure gauge) 3-5, fan 2-3, and insulating material 1-4 PMMA board in the present invention are all purchased on the market according to demand, and detailed functional parameters and specifications are not described here.

Claims

1. A visual quantitative measurement and analysis device for detecting the discharge degree on the surface of an insulating material, comprising a discharge simulation device, a charge visualization processing device and a complex environment simulation device; The discharge simulation device comprises an ESD gun, a discharge electrode, a ground electrode, an insulating material, a closed container, a high-voltage probe and an oscilloscope; The sealed container is a rectangular parallelepiped; the discharge electrode 1 is arranged in the sealed container, and is connected to the ESD gun 1 through one end of a copper rod extending out of the container; the high-voltage probe is connected to the copper rod outside the container through a soft copper wire with an insulating skin; the high-voltage probe transmits the collected discharge pulse waveform to the oscilloscope, and records the discharge waveform in real time; The insulating material is horizontally placed on the ground electrode 1; The ground electrode in the container is connected to the earth through a soft copper wire; The charge visualization processing device comprises a PMMA sealed container, an insulating fixture, insulating material, a fan and dust; The PMMA sealed container is a rectangular parallelepiped; the insulating fixture is annular in shape and made of epoxy resin, and is fixed to the bottom plate of the sealed container by a bracket, and the insulating material is vertically suspended in the center of the PMMA sealed container; the insulating material is PMMA; the fan is fixed to the bottom plates at the four corners of the PMMA sealed container by a bracket, and is controlled by an external power supply, and glass containers are placed under the fan to hold dust; The complex environment simulation device comprises: Discharge generator, humidifier, temperature and humidity meter, vacuum barrel, vacuum pump, pressure valve; The discharge generator comprises two ESD guns, two discharge electrodes, two ground electrodes, and insulating materials; the humidifier has remote control and timing functions, and is placed in a corner inside the vacuum barrel. The temperature and humidity meter can display the ambient temperature and humidity in real time; the vacuum barrel is a stainless steel barrel, which is equipped with a cover plate made of PMMA material. A hole is opened on the plate to allow the two discharge electrodes in the closed container to pass through. The end of the two discharge electrodes extending outside the vacuum barrel is connected to the two external ESD guns; the two ground electrodes in the container are connected to the earth through a soft copper wire; a through hole is opened on the wall of the vacuum barrel, and a connecting pipe at one end of the pressure valve is placed in the container. The pressure valve is provided with a pressure gauge, and the connecting pipe at the other end of the pressure valve is connected to a vacuum pump, and the vacuum pump is controlled to start and stop by an external power supply; the internal pressure of the vacuum barrel can be displayed in real time through the pressure gauge matching the pressure valve.

2. A visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claim 1, characterized in that: The insulating material has a plane size of 12*12 cm and a thickness of 4 mm.

3. A visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claim 1, characterized in that: The material of the sealed container is a customized transparent PMMA plate with a size of 100*80*60cm, which is convenient for observing the visual processing process.

4. A visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claim 1, characterized in that: The discharge electrode 1, discharge electrode 2, ground electrode 1 and ground electrode 2 are all spherical copper electrodes. The diameters of the discharge electrodes 1 and 2 are 2-4 cm, and the diameters of the copper ground electrodes 1 and 2 are 6-10 cm.

5. A visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claim 1, characterized in that: The four sets of fans are fixed directly above the dust through height-adjustable stainless steel brackets, and a glass container is placed under each fan for holding 10 ml of dust.

6. A visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claim 1, characterized in that: The dust is pink printer toner, which is spherical in shape and has a particle size of 5-100 μm.

7. A method for quantitative analysis using a visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claims 1 to 5, characterized in that: The method steps are as follows: S1. Before testing, assemble the discharge simulation device, charge visualization processing device and complex environment simulation device; Wipe the insulating material sample with alcohol and dry it; grounding a ground electrode 1 and testing the ground electrode 1; Fix the measuring wire on the discharge electrode 1, connect the high-voltage probe, adjust, measure and record the charging and discharging voltage of the stun gun, and connect the output end of the high-voltage probe to the oscilloscope; Accurately debug the external mobile power supply with timing function and connect it to the fan with adjustable air volume; Link debugging of various devices; Place 10ml of dust at the four corners of the capacitor; S2. Testing: The discharge is triggered by using an electrostatic discharge simulation device. Pulling the trigger of the ESD gun triggers the discharge, causing the copper discharge electrode to generate a high-voltage pulse at the needle tip, which breaks through the air for discharge, triggering discharge at the gas-solid interface, ionizing the air near the discharge electrode, and attaching positive charges to the surface of the insulating material. With the distortion of the local electric field, the discharge is further induced, spreading around with the discharge electrode as the core, forming a "sea urchin"-shaped discharge tree cluster. Use the charge visualization processing device to visualize the discharge charge, quickly remove the ESD gun, and fully discharge it before removal to prevent the residual charge from contacting the surface of the insulating material and causing secondary discharge; transfer the sample to the visualization device, start the fan to supply air for several seconds, so that the dust is evenly distributed in the discharge container; After the dust is adsorbed and the unadsorbed dust settles to the bottom of the container and stabilizes, open the container and blow away the excess dust on the surface of the insulating material, leaving a dust pattern, and take a photo to record the dust pattern; Processing of binary images, identifying and marking the effective discharge radius, setting the length of the single longest electrical tree branch as the effective discharge radius, cutting and retaining the effective discharge area; The image recognition device is activated to accurately identify the area where the pink toner is attached and flip its color to white, while the rest of the area is black; Track the image segmentation area, process the image into a binary image, use the program to count the number of white pixels and black pixels in the image, calculate the proportion of white pixels in the effective discharge space, and quantitatively characterize the intensity of this discharge; The calculation method first uses the classic Luminance algorithm to convert the pixels in the image between 0-255 to achieve grayscale conversion. The calculation formula is as follows: Gray(x,y)=0.299R(x,y)+0.587G(x,y)+0.114B(x,y) Where: R is the pixel value of the red channel, G is the pixel value of the green channel, B is the pixel value of the blue channel, and Gray is the grayscale value; Based on the above algorithm principle, the grayscale image is binarized. The principle is: by setting the critical grayscale value, hereinafter referred to as the threshold, the grayscale value greater than the threshold is set to the maximum grayscale value "255" to represent black, and the grayscale value less than the threshold is set to the minimum grayscale value "0" to represent white, so that the overall image appears in black and white. The main program running logic is as follows: Define the name of the desktop dust image, write access code, access the defined desktop image, read it into the main program, perform grayscale conversion and binarization processing, and count the number of black and white pixels through the program; Adjust the threshold according to the result until the shape of the electrical tree in the image before and after processing is highly consistent; write the output code, output the converted binary image and pixel point statistics, and save them to the desktop; In order to quantitatively describe the results output by the above program, the circle formed by the outer diameter of the longest electrical tree channel is the "effective discharge circumference", and the area ratio of the electrical tree within the effective discharge circumference is the "surface charge density". The "surface charge density" is introduced to quantitatively describe the development degree of positive polarity electrical tree; Calculate the number of pixels in the square image through the binarized histogram: Let the number of black pixels be A and the number of white pixels be B, then the diameter of the effective discharge circle is (A+B) 1 / 2 The total number of pixels contained in the effective discharge circle is π(A+B) 2 / 4, the number of white pixels is divided by the total number of pixels in the circle, and the surface charge density is obtained as 4B(A+B) -2 / π; S3. According to the measurement method described in S2, a complex environment simulation device is used to carry out electrostatic discharge tests under special environmental conditions of high humidity and low pressure, and the insulation failure mechanism in rainy weather and high altitude areas is studied respectively; the test adopts the control single variable method, and the single variables are relative humidity and atmospheric pressure; First, the single variable "relative humidity" is changed, and the relative humidity is selected as 20% RH and 90% RH, and the discharge temperature is kept at 20°C and the atmospheric pressure is kept at 100 kPa. By building a complex environmental simulation program, the start and stop of the humidifier is controlled to change the relative humidity of the discharge environment. To ensure the stability of the environmental humidity, the start and stop control is repeated; when the environmental humidity reaches the set value, it is maintained for a few seconds, and after waiting for a few minutes, the humidifier is started again, and the start and stop control is repeated; after the discharge is completed, the sample is quickly transferred and placed in the visualization processing system for visualization processing; Secondly, the single variable "atmospheric pressure" was changed, and the atmospheric pressure was selected to be 100 kPa, 80 kPa and 60 kPa, and the discharge temperature was kept at 20°C and the relative humidity was kept at 20% RH. By building a low-pressure system and adopting a repeated control method, the pressure gauge matched with the pressure valve can display the pressure in the vacuum barrel in real time. When the pressure reaches the set value, it will be maintained for a few seconds, the valve will be closed, the vacuum pump will be stopped, and the vacuum pump will be started again after waiting for tens of seconds. This operation will be repeated many times. After the discharge is completed, the pressure in the barrel needs to be quickly restored to the standard atmospheric pressure, and the sample must be quickly transferred to the visualization system for processing.

8. The method for analyzing using a visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of an insulating material according to claim 7, characterized in that: The duration of starting the fan to supply air in step S1 is 10 seconds.

9. The method for analyzing using the visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of insulating materials according to claim 7, characterized in that: The closed container in step S3 is a stainless steel vacuum barrel, an observation window is provided on the barrel body, and the observation window panel is made of an acrylic plate, a hole is opened on the observation window and sealed; the discharge electrode is placed in the container, the pressure valve is connected to the pipe in the container, and the other end is connected to the vacuum pump, and the device is started and stopped by an external power supply.

10. The method for analyzing using the visual quantitative measurement and analysis device for detecting the degree of discharge on the surface of insulating materials according to claim 7, characterized in that: In step S3, the air pressure is maintained for 10 seconds, the waiting time is 1 minute, and the start-stop control is repeated 5 times.

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