Insulator surface condensation discharge experiment method, system and storage medium

Abstract

The application relates to the technical field of electric power, in particular to an insulator surface condensation discharge experiment method and system and a storage medium, wherein the method comprises the following steps: forming artificial condensation on the surface of a post insulator in the mode of simulating natural condensation by artificial condensation; acquiring a first mass increase rate of unit surface area condensation and a first average diameter of unit time condensation, and stopping the simulation of natural condensation by artificial condensation until the first mass increase rate and the first average diameter both reach preset experimental requirements; and performing condensation discharge experiment on the surface of the insulator to obtain a condensation discharge spectrum. Therefore, the problems that the condensation formation time is long and the condensation state is not quantified in the related art post insulator surface condensation discharge experiment are solved.

Description

Technical Field

[0001] This application relates to the field of power technology, and in particular to a method, system and storage medium for condensation discharge test on the surface of an insulator. Background Technology

[0002] Currently, switchgear is a primary piece of equipment in power systems used for opening, closing, control, and protection, widely applied in power generation, transmission, and distribution, and plays a crucial role in the safety and reliability of power supply. Insulation failure is the leading cause of failures in KYN61-40.5kV armored withdrawable AC metal-enclosed switchgear. 85% of insulation failures are caused by partial discharge, with condensation on the insulation surface, especially when contaminated, leading to surface discharge, being the primary cause. Surface discharge caused by condensation, i.e., condensation discharge, is the leading cause of insulator breakdown and conductor-to-ground discharge in KYN61 switchgear, and can lead to serious accidents such as cabinet deformation and burnout of important components like circuit breakers and busbars, threatening the stability and safety of switchgear operation and posing a significant challenge to the reliability of power systems in factories or regions.

[0003] There are few reports on condensation discharge experiments on the surface of 35kV post insulators used in KYN61-40.5kV switchgear. Existing research on condensation discharge on the surface of insulating materials, such as the "Experimental Study on the Influence of Condensation State on the Flashover Characteristics of Silicone Rubber Insulation Surface," involves placing silicone rubber samples of the same size in a constant temperature and humidity chamber. The chamber is set to a low-temperature, low-humidity environment (temperature 0–5℃, humidity 20%–30%), and the samples are placed in this environment for 4 hours, ensuring that the temperature and humidity of the environment and the samples remain constant. The indoor temperature is adjusted to the required value at a heating rate of 3℃ / min, while the humidity is adjusted to the required conditions to induce condensation. The entire condensation formation process takes more than 4 hours, which is time-consuming and labor-intensive for repeated experiments. In the study on the discharge characteristics of epoxy resin insulation surface under condensation state, ultrasonic atomization, temperature control device, refrigeration platform, air compressor, cold press and other equipment were used to form condensation on the sample surface. Each condensation took 10 minutes, which shortened the condensation formation time, but the time was still relatively long. Moreover, the condensation on the insulation surface was quantified only from the condensation quality, without considering the condensation time, sample surface area and condensation size.

[0004] In related technologies, a maintenance-free, anti-pollution flashover, and anti-condensation external insulation component and its manufacturing method are described. The conductive layer and the conductive component achieve equipotential. Even when condensation occurs on the inner wall of the external insulation component at the corresponding inlet / outlet of the conductive component, no floating potential is generated. This method is used to avoid discharge phenomena caused by condensation, but it does not mention how to conduct condensation discharge experiments. An automatic and efficient condensation insulation testing device is also described, characterized by including a centralized control module, a sensing module, a steam heating module, a voltage boosting module, a test chamber module, and a sample platform. This reduces the need for personnel to enter and exit the test chamber to confirm its status and improves environmental control efficiency, but it does not mention how to quantitatively measure the condensation state on the sample surface. Summary of the Invention

[0005] This application provides a method, system, and storage medium for condensation discharge experiments on the surface of insulators, in order to solve the problems of long condensation formation time and lack of quantitative data on condensation state in related technologies during condensation discharge experiments on the surface of post insulators.

[0006] The first aspect of this application provides a method for conducting a condensation discharge experiment on an insulator surface, comprising the following steps: forming artificial condensation on the surface of a post insulator by simulating natural condensation; obtaining a first mass increase rate of condensation per unit surface area and a first average diameter of condensation per unit time, until both the first mass increase rate and the first average diameter reach preset experimental requirements, and then stopping the artificial condensation simulation of natural condensation; and conducting a condensation discharge experiment on the insulator surface to obtain a condensation discharge spectrum.

[0007] Alternatively, artificial condensation can be simulated by spraying the surface of the post insulator with a high-pressure spray gun to form artificial condensation.

[0008] Optionally, obtaining the first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time includes: acquiring a first image and a first weight of artificial condensation formed on the surface of the post insulator; identifying the first image to obtain the first average diameter of artificial condensation; calculating the first average diameter of condensation per unit time based on the artificial condensation simulation duration and the first average diameter; and calculating the first mass increase rate of condensation per unit surface area based on the area of ​​the insulator surface, the first weight, and the artificial condensation simulation duration.

[0009] Optionally, before the first mass increase rate and the first average diameter both reach the preset experimental requirements, the method further includes: subjecting the post insulator sample to natural condensation using a natural environment condensation simulation experimental device; acquiring a second image and a second weight of the natural condensation formed on the sample surface of the post insulator; identifying the second image to obtain a second average diameter of the natural condensation; calculating the second average diameter of the condensation per unit time based on the natural condensation duration and the second average diameter; determining a diameter range that meets the experimental requirements based on the second average diameter; calculating a second mass increase rate of condensation per unit surface area based on the area of ​​the insulator surface, the second weight, and the natural condensation duration; and determining a range of increase rates that meets the experimental requirements based on the second mass increase rate.

[0010] Optionally, the natural condensation simulation experiment device for the post insulator sample includes: setting a first target temperature and target relative humidity of the high and low temperature humidity chamber of the natural environment condensation simulation experiment device, and a second target temperature of the semiconductor cooling chip of the natural environment condensation simulation experiment device; turning on the high and low temperature humidity chamber until the actual temperature of the high and low temperature humidity chamber reaches the first target temperature and the actual humidity reaches the target humidity, maintaining this for a first preset time, and then starting the semiconductor cooling chip; after the actual temperature of the semiconductor cooling chip reaches the second target temperature, cooling the sample, cooling for a second preset time, and then turning off the semiconductor cooling chip to complete the natural condensation.

[0011] Optionally, the insulator surface condensation discharge test method further includes: performing grayscale processing and / or binarization processing on the first image or the second image.

[0012] A second aspect of this application provides an insulator surface condensation discharge experimental system, comprising: a post insulator; a high-voltage spray gun for spraying artificial condensation onto the surface of the post insulator; and an experimental assembly for performing a condensation discharge experiment on the surface of the post insulator with artificial condensation to obtain a condensation discharge spectrum.

[0013] Optionally, the experimental components include: a low-pass filter, a voltage regulating stage, a transformer, a protective resistor, a sealed cavity, a high-voltage electrode, a low-voltage electrode, a coupling capacitor, a detection impedance, and a partial discharge instrument. The input of the low-pass filter is connected to a power supply; the output of the low-pass filter is connected to the input of the voltage regulating stage; the output of the voltage regulating stage is connected to the input of the transformer; the high-voltage output of the transformer is connected to one end of the protective resistor; and the low-voltage output of the transformer is grounded. The other end of the protective resistor is connected to the high-voltage electrode and the high-voltage end of the coupling capacitor. The high-voltage electrode and the low-voltage electrode are placed on the upper surface of the sample, with a preset distance between them. The high-voltage electrode, the low-voltage electrode, and the sample are placed inside the sealed cavity. The low-voltage end of the coupling capacitor is connected to the input of the detection impedance; the grounding end of the detection impedance is grounded; the output of the detection impedance is connected to the corresponding input of the partial discharge instrument; and the partial discharge instrument outputs a measurement condensation discharge spectrum based on the partial discharge signal and reference voltage of the detection impedance.

[0014] Optionally, the filter cutoff frequency is a preset frequency, the maximum output voltage of the transformer should not be lower than the preset voltage, and the protection resistor is used to prevent overvoltage generated when the sample surface breaks down, which could damage other devices in the circuit.

[0015] A third aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the insulator surface condensation discharge experimental method as described in the above embodiments.

[0016] Therefore, this application has at least the following beneficial effects:

[0017] This application's embodiments can simulate natural condensation on the insulator surface using artificial condensation, while considering the first mass increase rate of condensation per unit surface area of ​​the insulation and the first average diameter of condensation per unit time. This shortens the condensation formation time during the condensation discharge experiment and ensures that artificial condensation can simulate natural condensation on the insulator surface, making the study and testing of condensation discharge on post insulators more time-saving and scientific. Therefore, it solves the technical problems in related technologies, such as long condensation formation time and lack of quantitative data on the condensation state, during condensation discharge experiments on post insulator surfaces.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 This is a flowchart of the insulator surface condensation discharge test method provided according to the embodiments of this application;

[0021] Figure 2 This is a schematic diagram illustrating the use of artificial condensation simulation according to the embodiments of this application;

[0022] Figure 3 This is a grayscale schematic diagram of artificial condensation on the surface of an insulator according to an embodiment of this application;

[0023] Figure 4 This is a binary schematic diagram of artificial condensation on the surface of an insulator according to an embodiment of this application;

[0024] Figure 5 This is a binary schematic diagram of natural condensation on the surface of an insulator according to an embodiment of this application;

[0025] Figure 6 This is a structural diagram of a natural environment condensation simulation experimental system provided according to an embodiment of this application;

[0026] Figure 7 This is a grayscale schematic diagram of natural condensation on the surface of an insulator according to an embodiment of this application;

[0027] Figure 8 A condensation discharge spectrum provided according to an embodiment of this application;

[0028] Figure 9 This is a schematic diagram of an insulator surface condensation discharge experimental system provided according to an embodiment of this application;

[0029] Figure 10 This is a structural diagram of a surface condensation discharge experimental system provided according to an embodiment of this application.

[0030] Figure labeling: 1 High-pressure nebulizer, 2 Sample, 3 Semiconductor cooling chip, 4 High and low temperature humidity chamber, 5 Low-pass filter, 6 Voltage regulating table, 7 Transformer, 8 Protective resistor, 9 Sealed cavity, 10 High-voltage electrode, 11 Low-voltage electrode, 12 Coupling capacitor, 13 Detection impedance, and 14 Partial discharge instrument. Detailed Implementation

[0031] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0032] The following description, with reference to the accompanying drawings, outlines an insulator surface condensation discharge experimental method, system, and storage medium according to embodiments of this application. Addressing the issue of long condensation formation time mentioned in the background art, this application provides an insulator surface condensation discharge experimental method. In this method, artificial condensation on the insulator surface can simulate natural condensation, while considering the first mass increase rate of condensation per unit surface area of ​​the insulation and the first average diameter of condensation per unit time. This shortens the condensation formation time during the condensation discharge experiment and ensures that artificial condensation can simulate natural condensation on the insulator surface, making the study and testing of condensation discharge on post insulators more time-saving and scientific. Therefore, it solves the problems of long condensation formation time and lack of quantitative data on condensation states in related technologies during condensation discharge experiments on post insulator surfaces.

[0033] Specifically, Figure 1 This is a schematic flowchart illustrating an insulator surface condensation discharge test method provided in an embodiment of this application.

[0034] like Figure 1 As shown, the experimental method for condensation discharge on the surface of the insulator includes the following steps:

[0035] In step S101, artificial condensation is formed on the surface of the post insulator by simulating natural condensation.

[0036] Among them, the artificial condensation method can simulate natural condensation by spraying the surface of the post insulator with a high-pressure spray gun to form artificial condensation; the post insulator can be the KYN61-40.5kV armored withdrawable AC metal-enclosed switchgear 35kV post insulator, or other models of insulators can be selected according to actual needs, without specific limitations.

[0037] It is understood that the embodiments of this application can use sheet-like samples, the same as those used for post insulators, to simulate artificial condensation on the surface of insulators. Artificial condensation is formed by simulating natural condensation, thereby achieving artificial simulation of surface condensation on insulators.

[0038] As an example, such as Figure 2 As shown, artificial condensation on the insulator surface can be simulated by spraying t onto the surface of sample 2 using a high-pressure atomizing gun 1. i Time implementation, t i The spray time is 1–5 seconds. The nozzle diameter of the high-pressure atomizing gun 1 is 1 mm, and the spray volume is <2 ml / s. The horizontal distance between the high-pressure atomizing gun 1 and the sample 2 is 800 mm, and the vertical distance is 800 mm. The nozzle of the high-pressure atomizing gun 1 is directly facing the sample 2 and is inclined at a 45° angle to the surface of the sample 2.

[0039] In step S102, the first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time are obtained. The artificial condensation simulation of natural condensation is stopped when both the first mass increase rate and the first average diameter reach the preset experimental requirements.

[0040] It is understood that, in this application embodiment, when the obtained first mass increase rate and first average diameter meet the preset experimental requirements, the artificial condensation simulation can be equivalent to natural condensation, and then the simulation of natural condensation by artificial condensation is stopped. In this application embodiment, obtaining the first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time includes: acquiring a first image and a first weight of artificial condensation formed on the surface of the post insulator; identifying the first image to obtain the first average diameter of the artificial condensation; calculating the first average diameter of condensation per unit time based on the artificial condensation simulation duration and the first average diameter; and calculating the first mass increase rate of condensation per unit surface area based on the area of ​​the insulator surface, the first weight, and the artificial condensation simulation duration.

[0041] The first image may undergo grayscale processing and / or binarization.

[0042] It is understood that the embodiments of this application can acquire a first image and a first weight of artificial condensation, identify the first average diameter of artificial condensation, obtain the first average diameter based on the condensation duration, and calculate the first mass increase rate of condensation per unit surface area based on the area of ​​the insulator surface, the first weight, and the artificial condensation duration.

[0043] For example, such as Figure 2 As shown, in the embodiments of this application, sample 2 can be prepared according to... Figure 2 Place horizontally, turn on the high-pressure atomizing gun 1, and spray t i The duration was measured, and the mass of sample 2 was recorded as m2. The rate of mass increase of condensation per unit surface area was obtained. Condensation was conducted using a high and low temperature humidity test chamber to obtain the first average diameter of condensation per unit time on the insulator surface.

[0044] Using a high-pressure spray gun to simulate artificial condensation on the insulator surface, the sample surface was sprayed for 3 seconds. The sample weight was measured to be 6.07 g. The first mass increase rate of condensation per unit surface area was G1 = 4.76 × 10⁻⁶. -6 g·mm -2 ·s -1 .get Figure 3 A photograph of surface condensation, after binarization, yields a binarized image, as shown below. Figure 4 As shown, the first average diameter of the condensation is calculated to be 1.7 mm, and the first average diameter of the condensation per unit time is D. a1 =0.57mm / s.

[0045] In this embodiment, before the first mass increase rate and the first average diameter both reach the preset experimental requirements, the method further includes: subjecting the post insulator sample to natural condensation using a natural environment condensation simulation experimental device; acquiring a second image and a second weight of the natural condensation formed on the sample surface of the post insulator; identifying the second image to obtain the second average diameter of the natural condensation; calculating the second average diameter of the condensation per unit time based on the natural condensation duration and the second average diameter; determining the diameter range that meets the experimental requirements based on the second average diameter; calculating the second mass increase rate of the condensation per unit surface area based on the area of ​​the insulator surface, the second weight, and the natural condensation duration; and determining the increase rate range that meets the experimental requirements based on the second mass increase rate.

[0046] The second image can be subjected to grayscale processing and / or binarization.

[0047] It is understood that the embodiments of this application can utilize a natural environment condensation simulation experimental device to conduct natural condensation, acquire a second image and a second weight, identify the average second diameter of the natural condensation, obtain the second average diameter based on the condensation duration, and calculate the second mass increase rate of condensation per unit surface area based on the area of ​​the insulator surface, the second weight, and the natural condensation duration.

[0048] Specifically, during the natural condensation process, all the condensation on the surface of sample 2 was wiped away with absorbent paper, and the mass of sample 2 was measured again and recorded as m1. Therefore, the mass of the condensation can be obtained as m. w =m0 - m1. The mass of the condensation, m w Sample 2, representing an insulator surface area of ​​S, is subjected to a temperature difference of T. s -T z The amount of condensation after natural condensation time in the environment is used to obtain the second mass increase rate of condensation per unit surface area. Surface condensation photographs are converted to 16-bit grayscale images, and binarization is performed on these images using an iterative self-organizing clustering algorithm. The diameter of each white region (representing condensation) in the binarized image is calculated. The binarized image of natural condensation is shown below. Figure 5 As shown, the diameter is taken as the maximum value of the Ferrette diameter, and from this, the average second diameter D of the condensation is obtained. a And the second average diameter D of condensation per unit time a0 .

[0049] The second average diameter of condensation per unit time during natural condensation is D. a0 The second mass increase rate of condensation per unit surface area is G0. Therefore, the diameter range that satisfies the experimental requirements is [0.9G0, 1.1G0], and the increase rate range that satisfies the experimental requirements is [0.9D]. a0 1.1D a0The experimental requirements can be determined according to the actual situation, and the range of settings can also be different for different experimental requirements, without specific limitations.

[0050] With a diameter range of [0.9G0, 1.1G0] and an increase rate range of [0.9D], a0 1.1D a0 For example, if 0.9G0≤G1≤1.1G0, and 0.9D a0 ≤D a1 ≤1.1D a0 Then it is considered that the spray t i The duration can be equivalent to the time taken at a temperature difference of T. s -T z In the environment of t c The amount of natural condensation after a certain time. Otherwise, adjust the spraying time t. i And repeat t multiple times i The duration of the spray is such that 0.9G0≤G1≤1.1G0, and 0.9D a0 ≤D a1 ≤1.1D a0 .

[0051] As an example, the average diameter of the condensation is 2.7 mm, and the average diameter of the condensation per unit time is D. a0 =0.54 mm / s. Based on artificial condensation simulation on the insulator surface, the mass increase rate of condensation per unit surface area is G1 = 4.76 × 10⁻⁶. -6 g·mm -2 ·s -1 The average diameter D of condensation per unit time a1 = 0.57 mm / s, according to 0.9G0≤G1≤1.1G0, and 0.9D a0 ≤D a1 ≤1.1D a0 We get 4.41 × 10 -6 ≤4.76×10 -6 ≤5.39×10 -6 And 0.49≤0.57≤0.59, it is considered that spraying for 3 seconds can be equivalent to the amount of natural condensation after 5 seconds in an environment with a temperature difference of 35℃.

[0052] In this embodiment, a natural condensation simulation test device is used to perform natural condensation on the sample of the post insulator. The process includes: setting a first target temperature and target relative humidity of the high and low temperature humidity chamber of the natural environment condensation simulation test device, and a second target temperature of the semiconductor cooling chip of the natural environment condensation simulation test device; turning on the high and low temperature humidity chamber until the actual temperature of the high and low temperature humidity chamber reaches the first target temperature and the actual humidity reaches the target humidity, maintaining this for a first preset time, and then starting the semiconductor cooling chip; after the actual temperature of the semiconductor cooling chip reaches the second target temperature, cooling is performed on the sample, and the cooling continues for a second preset time before the semiconductor cooling chip is turned off, thus completing the natural condensation.

[0053] The first target temperature can be 25℃, the target relative humidity can be 90%RH, the second target temperature can be 0℃, the first preset duration can be 15min, and the second preset duration can be specifically calibrated.

[0054] It is understood that the embodiments of this application can set a first target temperature and target relative humidity of the high and low temperature humidity chamber, and a second target temperature of the semiconductor cooling chip. When the temperature of the high and low temperature humidity chamber reaches the first target temperature and the actual humidity reaches the target humidity, the cooling duration is stabilized, and then the semiconductor cooling chip is started. After reaching the second target temperature, the sample is cooled, and the power supply of the semiconductor cooling chip is turned off for a period of time, thereby completing natural condensation.

[0055] As an example, the condensation on the surface of the 35kV post insulators of the KYN61-40.5kV armored withdrawable AC metal-enclosed switchgear during operation is related to temperature and humidity. To obtain the natural condensation pattern on the insulator surface, the natural condensation process was completed in a high and low temperature humidity test chamber. Figure 6 As shown, the natural environment condensation simulation experimental system consists of sample 2, a thermoelectric cooler 3, and a high-low temperature humidity chamber 4. The high-low temperature humidity chamber 4 is used to control temperature and humidity; the temperature control range should meet the requirement of -25℃ to 150℃; the humidity control range should meet the requirement of 20%RH to 98%RH. Sample 2 is taken from a 35kV post insulator. The dimensions of the sheet-like sample should meet the requirements of length ≥ 25mm, width ≥ 25mm, and thickness ≤ 2mm, and it is placed flat on the thermoelectric cooler 3. The thermoelectric cooler 3 has a temperature control range of -25℃ to room temperature and is used to control the temperature of sample 2, ensuring a temperature difference between the surface temperature of sample 2 and the temperature inside the high-low temperature humidity chamber 4.

[0056] The temperature of the high and low temperature humidity chamber 4 is set to T. s T s ≥25℃, relative humidity of H s H s >90%, the temperature of semiconductor refrigeration chip 3 is T z Tz <0℃; turn on the high and low temperature humidity chamber 4 and wait for its temperature to reach T. s and humidity reach H s After stabilizing for 15 minutes, the thermoelectric cooler 3 is activated and allowed to reach temperature T. z Then, sample 2 was cooled for a duration of t. c Turn off the power to the semiconductor cooler 3, remove sample 2, and immediately measure the mass of sample 2, recording it as m0. Take a photograph of the surface condensation perpendicular to the upper surface of the sample, as shown below. Figure 7 As shown.

[0057] For example, the temperature of the cable compartment in a KYN61-40.5kV armored withdrawable AC metal-enclosed switchgear is 10℃, the insulator surface temperature is 45℃, and the relative humidity is 80%. A sample made of the same material as the 35kV post insulator, measuring 70mm×70mm×1mm (length×width×height), with a mass of approximately 6g, is taken. The temperature of the high-low temperature humidity chamber is set to 45℃, and the relative humidity to 80%. After the temperature and humidity of the high-low temperature humidity chamber reach the set values ​​for 15 minutes, the sample is placed on the thermoelectric cooler in the chamber. The thermoelectric cooler temperature is set to 10℃ and activated. After 5 minutes, the sample is removed and weighed; the sample weighs approximately 6.12g. Therefore, the mass of condensation is m. w =6.12 - 6 = 0.12 g. The rate of increase in mass of condensation per unit surface area is G0 = 4.9 × 10⁻⁶ g. -6 g·mm -2 ·s -1 .

[0058] In step S103, a condensation discharge experiment is performed on the surface of the insulator to obtain a condensation discharge spectrum.

[0059] It is understood that, in the embodiments of this application, the surface condensation discharge experiment can be conducted based on the rated voltage of the post insulator, and the voltage can be gradually increased to a preset percentage of that voltage to obtain the condensation discharge spectrum.

[0060] As an example, such as Figure 8 As shown, the rated voltage of the 35kV post insulator is 35kV. The voltage is gradually increased to 50% of that voltage, i.e., 17.5kV, and the condensation discharge spectrum at 17.5kV is measured.

[0061] The insulator surface condensation discharge experimental method proposed in this application can simulate natural condensation on the insulator surface using artificial condensation. It considers both the first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time, thus shortening the condensation formation time during the condensation discharge experiment and ensuring that artificial condensation can simulate natural condensation on the insulator surface. This makes the study and testing of condensation discharge on post insulators more time-saving and scientific. Therefore, it solves the problems of long condensation formation time and lack of quantitative data on condensation state in related technologies during condensation discharge experiments on post insulator surfaces.

[0062] The experimental method for condensation discharge on the surface of insulators will be described in detail below:

[0063] (1) Set the temperature of the high and low temperature humidity chamber to T. s The relative humidity is H s The temperature of the semiconductor refrigeration chip is T. z Turn on the high and low temperature humidity chamber and wait for its temperature to reach T. s and humidity reach H s And remain stable for 15 minutes.

[0064] Turn on the thermoelectric cooler and wait for its temperature to reach T. z Then, the sample was cooled for a duration of t. c Turn off the power to the thermoelectric cooler, remove the sample, and immediately measure the mass m0 of the sample. Take a photograph of the surface condensation perpendicular to the upper surface of the sample.

[0065] (2) Wipe away all the condensation on the surface of the sample with absorbent paper, and measure the mass of the sample m1 again. The mass of the condensation can then be obtained as m. w The rate of mass increase of condensation per unit surface area is G0. The surface condensation photographs are converted to 16-bit grayscale images and binarized to obtain the maximum and average Freret diameters of the condensation, D. a And the average diameter D of condensation per unit time a0 .

[0066] (3) Place the sample horizontally, turn on the high-pressure atomizing gun, and spray t i The duration is measured, the mass m2 of the sample is measured, the mass increase rate of condensation per unit surface area is obtained as G1, and the average diameter D of condensation per unit time on the insulator surface is obtained. a1 .

[0067] (4) Compare G1 and G0, D a1 With D a0 If 0.9G0≤G1≤1.1G0, and 0.9D a0 ≤D a1 ≤1.1D a0 Then it is considered that the spray ti The duration can be equivalent to the time taken at a temperature difference of T. s -T z In the environment of t c The amount of natural condensation after a certain time. Otherwise, adjust the spraying time t. i And repeat t multiple times i The duration of the spray is such that 0.9G0≤G1≤1.1G0, and 0.9D a0 ≤D a1 ≤1.1D a0 Using the surface condensation discharge experimental system, the power supply of the experimental system is turned on, and the voltage regulating table 6 is controlled to gradually increase the output voltage of the partial discharge-free AC step-up test transformer from 0 to the required measurement voltage. The condensation discharge spectrum is obtained by measuring with a partial discharge instrument.

[0068] In summary, the embodiments of this application establish the relationship between natural condensation and artificial condensation through natural condensation on the insulator surface, artificial condensation simulation on the insulator surface, and surface condensation discharge experiments. This enables the artificial simulation of surface condensation on insulators and the acquisition of its condensation discharge spectrum, shortening the condensation formation time, quantifying the condensation state, and improving the experimental efficiency of condensation discharge experiments.

[0069] Next, referring to the accompanying drawings, we describe the insulator surface condensation discharge experimental system proposed according to the embodiments of this application.

[0070] Figure 9 This is a block diagram of the insulator surface condensation discharge experimental system according to an embodiment of this application.

[0071] like Figure 9 As shown, the insulator surface condensation discharge test system 20 includes: a post insulator 100, a high-voltage spray gun 200, and an experimental assembly 300.

[0072] Among them, the high-pressure spray gun 200 is used to spray the surface of the post insulator to form artificial condensation; the experimental component 300 is used to conduct a condensation discharge experiment on the surface of the post insulator with artificial condensation to obtain the condensation discharge spectrum.

[0073] It is understood that, in the embodiments of this application, a high-pressure spray gun 200 can be used to simulate artificial condensation on the surface of an insulator, spraying onto the sample surface for 3 seconds to conduct a surface condensation discharge experimental system, and using the surface condensation discharge experimental method, a condensation discharge laboratory is conducted to obtain a condensation discharge spectrum.

[0074] In this embodiment, the experimental component 300 includes: a low-pass filter 5, a voltage regulating platform 6, a transformer 7, a protective resistor 8, a sealed cavity 9, a high-voltage electrode 10, a low-voltage electrode 11, a coupling capacitor 12, a detection impedance 13, and a partial discharge instrument 14.

[0075] The input of the low-pass filter 5 is connected to the power supply, the output of the low-pass filter 5 is connected to the input of the voltage regulating platform 6, the output of the voltage regulating platform 6 is connected to the input of the transformer 7, the high-voltage output of the transformer 7 is connected to one end of the protective resistor 8, and the low-voltage output of the transformer 7 is grounded; the other end of the protective resistor 8 is connected to the high-voltage electrode 10 and the high-voltage end of the coupling capacitor 12, the high-voltage electrode 10 and the low-voltage electrode 11 are placed on the upper surface of the sample 2, the distance between the two electrodes is preset, the high-voltage electrode 10, the low-voltage electrode 11 and the sample 2 are placed inside the sealed cavity 9, the low-voltage end of the coupling capacitor 12 is connected to the input of the detection impedance 13, the grounding end of the detection impedance 13 is grounded, the output of the detection impedance 13 is connected to the corresponding input of the partial discharge instrument 14, and the partial discharge instrument 14 outputs a measurement condensation discharge spectrum based on the partial discharge signal and reference voltage of the detection impedance 13.

[0076] In this embodiment, the filter cutoff frequency is a preset frequency, the maximum output voltage of the transformer should not be lower than the preset voltage, and the protection resistor is used to prevent overvoltage from damaging other devices in the circuit when the sample surface breaks down.

[0077] The preset voltage can be specifically calibrated, such as 50kV, and the preset frequency can be 1kHz.

[0078] As an example, the surface condensation discharge experimental system used, such as Figure 10 As shown, it includes a low-pass filter 5, a voltage regulator 6, a transformer 7, a protective resistor 8, a sealed cavity 9, a high-voltage electrode 10, a low-voltage electrode 11, a coupling capacitor 12, a detection impedance 13, and a partial discharge meter 14.

[0079] The low-pass filter 5 has its input connected to 380V AC mains power and its output connected to the input of the voltage regulator 6. The filter's cutoff frequency is 1kHz. The output of the voltage regulator 6 is connected to the input of the partial discharge-free AC step-up test transformer 7 to adjust its output voltage. The maximum output voltage of the partial discharge-free AC step-up test transformer 7 should not be less than 50kV. The high-voltage end of the output is connected to one end of the protective resistor 8, and the low-voltage end is grounded. The protective resistor 8 is used to prevent overvoltage damage to other equipment in the circuit caused by surface breakdown of the sample 2. Its value is selected at 0.1Ω / kV based on the maximum output voltage of the partial discharge-free AC step-up test transformer 7, and its rated operating voltage should not be lower than the maximum output voltage of the partial discharge-free AC step-up test transformer 7.

[0080] The other end of the protective resistor 8 is connected to the high-voltage terminal of the high-voltage electrode 10 and the coupling capacitor 12. The high-voltage electrode 10 and the ground electrode 11 are stainless steel electrodes with a diameter of 70 mm, placed on the upper surface of the sample 2, with a minimum distance of 20 mm between the two electrodes. The high-voltage electrode 10, the low-voltage electrode 11, and the sample 2 are placed inside the sealed cavity 9 to prevent changes in condensation on the sample surface due to air flow. The low-voltage terminal of the coupling capacitor 12 is connected to the input of the detection impedance 13, and the ground terminal of the detection impedance 13 is grounded. The partial discharge signal output and the reference voltage output of the detection impedance 13 are connected to the corresponding input terminals of the partial discharge instrument 14, which is used to measure the condensation discharge spectrum.

[0081] In this embodiment, the surface condensation discharge experiment process involves forming a certain amount of condensation on the surface of sample 2 according to the surface condensation discharge experiment system and the artificial condensation simulation method on the insulator surface. The power supply of the experiment system is turned on, and the voltage regulating platform 6 is controlled to gradually increase the output voltage of the partial discharge-free AC step-up test transformer 7 from 0 to the required measurement voltage. The condensation discharge spectrum is then measured by the partial discharge instrument 14.

[0082] It should be noted that the foregoing explanation of the insulator surface condensation discharge test method embodiment also applies to the insulator surface condensation discharge test system of this embodiment, and will not be repeated here.

[0083] The surface condensation discharge experimental system for insulators proposed in this application consists of a low-pass filter, a voltage regulating platform, a partial discharge-free AC step-up test transformer, a protective resistor, a sealed cavity, high-voltage electrodes, low-voltage electrodes, coupling capacitors, a detection impedance, and a partial discharge meter. Artificial condensation on the insulator surface simulates natural condensation, while considering the first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time. This shortens the condensation formation time during the condensation discharge experiment and ensures that artificial condensation can simulate natural condensation on the insulator surface, making the study and testing of condensation discharge on post insulators more time-saving and scientific. Therefore, it solves the problems of long condensation formation time and lack of quantitative data on condensation states in related technologies for surface condensation discharge experiments on post insulators.

[0084] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described insulator surface condensation discharge experimental method.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0087] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0088] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0089] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0090] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for conducting condensation discharge experiments on the surface of an insulator, characterized in that, Includes the following steps: Artificial condensation is formed on the surface of post insulators by simulating natural condensation. The first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time are obtained. The artificial condensation simulation of natural condensation is stopped when both the first mass increase rate and the first average diameter reach the preset experimental requirements. A condensation discharge experiment was conducted on the surface of the insulator to obtain a condensation discharge spectrum. The process, which continues until both the first mass increase rate and the first average diameter meet the preset experimental requirements, also includes: Natural condensation was simulated on post insulator samples using a natural environment condensation simulation experimental device. A second image and a second weight of the natural condensation formed on the surface of the post insulator sample were acquired. The second average diameter of the natural condensation is obtained by identifying the second image. The second average diameter of the condensation per unit time is calculated based on the natural condensation duration and the second average diameter. The diameter range that meets the experimental requirements is determined based on the second average diameter. The second mass increase rate of condensation per unit surface area is calculated based on the area of ​​the insulator surface, the second weight, and the natural condensation time. Based on the second mass increase rate, the range of increase rates that meet the experimental requirements is determined.

2. The insulator surface condensation discharge test method according to claim 1, characterized in that, Artificial condensation can simulate natural condensation in the following ways: Artificial condensation is formed by spraying the surface of the post insulator with a high-pressure spray gun.

3. The insulator surface condensation discharge test method according to claim 1, characterized in that, The acquisition of the first mass increase rate of condensation per unit surface area and the first average diameter of condensation per unit time includes: Acquire a first image and a first weight of the artificial condensation formed on the surface of the post insulator; The first average diameter of artificial condensation is obtained by identifying the first image, and the first average diameter of condensation per unit time is calculated based on the artificial condensation simulation duration and the first average diameter. The first mass increase rate of condensation per unit surface area is calculated based on the area of ​​the insulator surface, the first weight, and the duration of the artificial condensation simulation.

4. The insulator surface condensation discharge test method according to claim 1, characterized in that, The method of using a natural environment condensation simulation experimental device to conduct natural condensation on the samples of the post insulator includes: The first target temperature and target relative humidity of the high and low temperature humidity chamber of the natural environment condensation simulation experimental device are set, as well as the second target temperature of the semiconductor cooling chip of the natural environment condensation simulation experimental device. Turn on the high and low temperature humidity chamber and maintain it for a first preset time until the actual temperature of the high and low temperature humidity chamber reaches the first target temperature and the actual humidity reaches the target humidity. Then start the semiconductor cooling chip. After the actual temperature of the semiconductor cooling chip reaches the second target temperature, the sample is cooled. After the cooling continues for a second preset time, the semiconductor cooling chip is turned off to complete natural condensation.

5. The insulator surface condensation discharge test method according to claim 3 or 1, characterized in that, Also includes: Perform grayscale processing and / or binarization processing on the first image or the second image.

6. A system for testing condensation discharge on the surface of an insulator, characterized in that, include: Post insulators; A high-pressure spray gun is used to spray artificial condensation onto the surface of the post insulator; An experimental component is used to conduct a condensation discharge experiment on the surface of a post insulator with artificial condensation as described in any one of claims 1-5 to obtain a condensation discharge spectrum.

7. The insulator surface condensation discharge experimental system according to claim 6, characterized in that, The experimental components include: a low-pass filter, a voltage regulating platform, a transformer, a protective resistor, a sealed cavity, high-voltage electrodes, low-voltage electrodes, coupling capacitors, a detection impedance, and a partial discharge analyzer. The input of the low-pass filter is connected to a power supply, and the output of the low-pass filter is connected to the input of the voltage regulating station. The output of the voltage regulating station is connected to the input of the transformer. The high-voltage output of the transformer is connected to one end of the protective resistor, and the low-voltage output of the transformer is grounded. The other end of the protective resistor is connected to the high-voltage electrode and the high-voltage end of the coupling capacitor. The high-voltage electrode and the low-voltage electrode are placed on the upper surface of the sample, with a preset distance between them. The high-voltage electrode, the low-voltage electrode, and the sample are placed inside the sealed cavity. The low-voltage end of the coupling capacitor is connected to the input of the detection impedance, and the grounding end of the detection impedance is grounded. The output of the detection impedance is connected to the corresponding input of the partial discharge instrument. The partial discharge instrument outputs a measurement condensation discharge spectrum based on the partial discharge signal and reference voltage of the detection impedance.

8. The insulator surface condensation discharge experimental system according to claim 7, characterized in that, The filter cutoff frequency is a preset frequency, the maximum output voltage of the transformer should not be lower than the preset voltage, and the protection resistor is used to prevent overvoltage generated when the sample surface breaks down and damages other equipment in the circuit.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the insulator surface condensation discharge test method as described in any one of claims 1-5.

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