Insulation and voltage resistance test method and test system for three-post insulator

Abstract

According to the three-post insulator insulation and voltage resistance test method and test system provided by the invention, the target insulator model is subjected to scaling printing through the 3D printer, and the target insulator model is printed in a scaling-down manner through the 3D printing technology, so that on one hand, high cost of a metal mold is avoided, and scaling printing can further save resources and reduce cost; on the other hand, the production cycle of the target insulator model can be shortened, the test efficiency can be improved, then the flashover test is carried out on the target insulator model in the power frequency withstand voltage test system by using the scaling test tool and the target insulator model in a stepped boosting mode, and the flashover voltage of the target insulator model is recorded for preset times; and carrying out fitting analysis on the recorded flashover voltage to obtain a characteristic voltage so as to realize evaluation of the insulation and voltage resistance of the insulator. And multiple flashover voltages are recorded in the evaluation process, so that errors are avoided to the greatest extent, and the accuracy of evaluating the insulation and voltage resistance performance of the target insulator model is improved.

Description

Technical Field

[0001] The present application relates to the technical field of performance evaluation, and in particular to a three-pillar insulator insulation withstand voltage test method and test system. Background Art

[0002] Compared with traditional transmission methods, gas-insulated transmission lines (GIL) have the advantages of high capacity and no insulation aging. The three-pillar insulator in the GIL supports the central conductor. Its abdomen wraps the central conductor, and the three legs are fixed to the ground electrode through metal inserts. The three-pillar insulator is one of the key components of the internal insulation of the GIL. It is easy to cause partial discharge or surface flashover due to insufficient insulation margin, resulting in GIL insulation failure.

[0003] At present, in order to ensure that the insulation withstand voltage performance of three-pillar insulators reaches the expected standard, the insulation withstand voltage performance of three-pillar insulators can be verified by testing. However, in the process of testing the insulation performance of three-pillar insulators, the metal molds used to produce three-pillar insulators are difficult to have universality and cannot flexibly cover three-pillar insulators with different structural parameters, resulting in high testing costs and low efficiency. Summary of the invention

[0004] The purpose of the present application is to solve at least one of the above-mentioned technical defects, especially the technical defects of high test cost and low efficiency in the prior art in which the metal molds for producing three-pillar insulators are difficult to be universal and cannot flexibly cover three-pillar insulators with different structural parameters.

[0005] In a first aspect, the present application provides a three-pillar insulator insulation withstand voltage test method, the method comprising:

[0006] Printing a target insulator model in scale by a 3D printer, wherein the target insulator model is a scaled model of a three-pillar insulator after structural parameter optimization;

[0007] Obtaining a scaled-down test fixture, and assembling the target insulator model into the scaled-down test fixture, and after obtaining the target test fixture, installing the target test fixture into a power frequency withstand voltage test system;

[0008] In the power frequency withstand voltage test system, a flashover test is performed on the target insulator model by adopting a step-by-step voltage-rising method, and the flashover voltage of the target insulator model is recorded for a preset number of times during the flashover test;

[0009] The recorded flashover voltage is fitted and analyzed to determine the characteristic voltage of the target insulator model, and the insulation withstand voltage performance of the target insulator model is evaluated based on the characteristic voltage.

[0010] In one embodiment, the step of printing the target insulator model in scale using a 3D printer includes:

[0011] Prepare a filler and a base material, wherein the filler is an inorganic material with a high dielectric constant, and the base material is a photosensitive resin material;

[0012] Adding the filler into the base material in batches, and stirring to fully mix the filler and the base material to obtain a mixed suspension;

[0013] The mixed suspension is subjected to defoaming treatment, and a target insulator model is printed in scale based on the mixed suspension subjected to the defoaming treatment using a 3D printer.

[0014] In one embodiment, assembling the target insulator model into the scaled test fixture includes:

[0015] The target insulator model is sleeved on the central conductor in the scaled test fixture to obtain the target test fixture, wherein the scaled test fixture comprises a central conductor, a grounding shell and a metal ball, wherein the central conductor is embedded in the grounding shell, and both ends of the central conductor are outside the grounding shell, wherein one end is used to be connected to a high potential end, and the other end is connected to the metal ball.

[0016] In one embodiment, the step of installing the target test tooling to the power frequency withstand voltage test system includes:

[0017] The target test tool is placed in the closed test chamber of the power frequency withstand voltage test system, and one end of the central conductor in the target test tool is connected to the high-voltage bushing in the power frequency withstand voltage test system to connect to the high potential end, and the grounded shell of the target test tool is grounded.

[0018] In one embodiment, the flashover test is performed on the target insulator model in a step-by-step voltage-boosting manner in the power frequency withstand voltage test system, and the flashover voltage of the target insulator model is recorded a preset number of times during the flashover test, including:

[0019] Fill the closed test chamber of the power frequency withstand voltage test system with gas;

[0020] In a flashover test, the target test fixture is subjected to multiple step-by-step voltage boosting according to a preset voltage boosting step length and a preset interval;

[0021] During multiple step-by-step voltage increases, after recording the flashover voltage of the target insulator model, determine whether the number of records reaches the preset number. If not, enter the next flashover test. If so, obtain the flashover voltage of the target insulator model recorded multiple times.

[0022] In one embodiment, performing fitting analysis on the recorded flashover voltage to determine the characteristic voltage of the target insulator model includes:

[0023] Determine the probability density function;

[0024] A likelihood function is constructed according to the probability density function and the recorded flashover voltage, and the likelihood function is solved to obtain a scale parameter corresponding to the probability density function, and the scale parameter is used as the characteristic voltage of the target insulator model.

[0025] In one embodiment, the probability density function is expressed as:

[0026]

[0027] In the formula, For the The flashover probability of a flashover voltage is For the The voltage value of the flashover voltage, represents the number of recorded flashover voltages, β is the shape parameter, representing the dispersion of the flashover voltage, and α is the scale parameter, representing the voltage value when the flashover probability is the preset probability, that is, the characteristic voltage.

[0028] In one embodiment, the evaluating the insulation withstand voltage performance of the target insulator model based on the characteristic voltage includes:

[0029] When the insulation withstand voltage performance of the target insulator model is compared and evaluated, the characteristic voltage of the reference insulator model is determined, and the characteristic voltage of the target insulator model is compared with the characteristic voltage of the reference insulator model to measure whether the insulation withstand voltage performance of the target insulator is improved; the reference insulator model is a scaled model of a three-pillar insulator before structural parameter optimization;

[0030] When the insulation withstand voltage performance of the target insulator model is evaluated, the performance level corresponding to the characteristic voltage is searched in a preset information table to evaluate the insulation withstand voltage performance of the target insulator model.

[0031] In a second aspect, the present application provides a power frequency withstand voltage test system, the system comprising a transformer, a current limiting resistor, a resistor-capacitor voltage divider, a closed test chamber, a high-speed camera and a high-voltage bushing;

[0032] The transformer is connected to a first end of the current-limiting resistor, and a second end of the current-limiting resistor is connected to the RC voltage divider and the high-voltage bushing respectively;

[0033] The high-voltage bushing is placed above the closed test chamber, and the high-speed camera is placed in front of the observation window of the closed test chamber to shoot the flashover process of the target insulator model;

[0034] The RC voltage divider is used to record the flashover voltage of the target insulator model, and the closed test chamber is used to place the target test fixture to perform a flashover test on the target test fixture.

[0035] In one embodiment, the voltage division ratio of the RC voltage divider is 2000:1.

[0036] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0037] The present application provides a three-pillar insulator insulation withstand voltage test method and test system, the method comprising: printing a target insulator model in scale by a 3D printer, the target insulator model being a scaled model of a three-pillar insulator after structural parameter optimization; printing the target insulator model in a scaled-down manner by 3D printing technology, on the one hand avoiding the high cost of metal molds, and scaled printing can further save resources and reduce costs, on the other hand shortening the production cycle of the target insulator model and improving test efficiency, then obtaining a scaled-down test tooling, assembling the target insulator model into the scaled-down test tooling, after obtaining the target test tooling, installing the target test tooling into a power frequency withstand voltage test system; then performing a flashover test on the target insulator model in a step-by-step voltage-boosting manner in the power frequency withstand voltage test system, and after recording the flashover voltage of the target insulator model for a preset number of times during the flashover test, performing a fitting analysis on the recorded flashover voltage to determine the characteristic voltage of the target insulator model, and evaluating the insulation withstand voltage performance of the target insulator model based on the characteristic voltage. By performing a flashover test and recording the flashover voltage of the target insulator model, the insulation withstand voltage performance of the target insulator model can be evaluated. Multiple flashover voltages are recorded to avoid errors to the greatest extent and improve the accuracy of the insulation withstand voltage performance evaluation of the target insulator model. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 A schematic flow chart of a three-pillar insulator insulation withstand voltage test method provided in an embodiment of the present application;

[0040] Figure 2 An exemplary diagram of a three-pillar insulator insulation withstand voltage test method provided in an embodiment of the present application;

[0041] Figure 3 A schematic diagram of the structure of a power frequency withstand voltage test system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] like Figure 1 As shown, the present application provides a three-pillar insulator insulation withstand voltage test method, the method comprising:

[0044] S101: Printing a target insulator model in scale using a 3D printer.

[0045] Among them, the target insulator model is a scaled-down model of a three-pillar insulator after structural parameter optimization.

[0046] In this step, after the user optimizes the structural parameters of the three-pillar insulator, the insulation withstand voltage performance of the three-pillar insulator is generally tested or verified. At this time, the three-pillar insulator structure to be tested or verified can be obtained, and the three-pillar insulator structure can be printed out using a 3D printer according to a certain reduction ratio to obtain the target insulator model.

[0047] Specifically, when printing the target insulator model, the reduction ratio can be determined in combination with factors such as the complexity and fineness of the target insulator model and actual needs. For example, the reduction ratio can be 1 / 2 of the insulator structure to be tested or verified, and the reduction ratio is 0.5 at this time, and the present application does not impose specific restrictions on this. In addition, when printing the target insulator model, a reasonable printing layer thickness and printer light irradiation time can be set to print the target insulator model, wherein the printing layer thickness can be determined in combination with relevant factors such as model accuracy and printer performance, and the printer light irradiation time can be determined in combination with relevant factors such as printing layer thickness, material curing characteristics, ambient temperature and humidity, etc.

[0048] In one example, the 3D printer may be a stereolithography 3D printer.

[0049] S102: Obtain a scaled-down test jig, and assemble the target insulator model into the scaled-down test jig. After obtaining the target test jig, install the target test jig into a power frequency withstand voltage test system.

[0050] In this step, a pre-prepared scaled test fixture is obtained, and then the printed target insulator model is assembled into the scaled test to obtain the target test fixture, and then the target test fixture is placed in the corresponding position in the pre-set power frequency withstand voltage test system to perform a flashover test on the target insulator model.

[0051] Among them, the scaled test fixture refers to the test device used to place the target insulator model, and the power frequency withstand voltage test system refers to the system used to perform flashover test on the test device with the target insulator model placed. It can be understood that the flashover test is a test method for detecting the insulation performance of electrical equipment (insulators), which is mainly used to evaluate the insulation performance and reliability of insulating materials or insulating structures under high voltage.

[0052] S103: performing a flashover test on the target insulator model in a power frequency withstand voltage test system by adopting a step-by-step voltage-rising method, and recording the flashover voltage of the target insulator model for a preset number of times during the flashover test.

[0053] Among them, the flashover voltage refers to the voltage value corresponding to the flashover phenomenon caused by the breakdown of the gas on the surface of the target insulator model under certain conditions to form a conductive channel. It is a key indicator to measure the insulation performance of the insulator, and its value directly reflects the ability of the insulator to withstand high voltage.

[0054] In this step, when the target insulator model is subjected to a flashover test based on the power frequency withstand voltage test system, a step-by-step voltage increase method is used for voltage application. First, a certain initial voltage is applied. For example, a fixed voltage value can be increased each time according to a pre-set voltage increment, such as increasing by 2kV each time. Relevant rules can also be set to dynamically determine the voltage value increased each time. The present application does not impose any specific restrictions on the specific method of applying voltage. After each voltage application, the voltage value is maintained for a period of time, such as 5-10 seconds, to observe whether the target insulator model flashes over. If no flashover occurs, the voltage is continued to be increased step by step, and the above process is repeated until a flashover occurs. When the flashover occurs, the voltage value at this time is recorded. At this time, the recording of a flashover voltage is completed. This is repeated for a preset number of times to obtain multiple flashover voltage data.

[0055] It is understandable that in the above process, the voltage increment, the holding time and the preset number of times can be adjusted according to the test requirements, actual conditions, etc. This application does not impose any specific restrictions on this.

[0056] S104: performing fitting analysis on the recorded flashover voltage to determine the characteristic voltage of the target insulator model, and evaluating the insulation withstand voltage performance of the target insulator model based on the characteristic voltage.

[0057] In this step, after obtaining multiple flashover voltages, the multiple flashover voltages can be sorted and preprocessed. If there are obviously abnormal data points, the obviously abnormal data points can be considered to be eliminated to ensure the reliability of the flashover data. Then select a suitable fitting model, such as a two-parameter Weibull distribution model, substitute the sorted and preprocessed flashover data into the model, and calculate the characteristic voltage using mathematical methods such as maximum likelihood estimation. After obtaining the characteristic voltage, the insulation withstand voltage performance of the target insulator model can be measured by comparing the characteristic voltage with the reference voltage or the reference voltage range, and then the insulation withstand voltage performance of the actual insulator structure can be evaluated.

[0058] The characteristic voltage refers to the voltage value at which the corresponding insulator is likely to flash over. The larger the characteristic voltage, the greater the insulator flashover voltage under the current conditions.

[0059] The present application provides a three-pillar insulator insulation withstand voltage test method and test system, the method comprising: printing a target insulator model in scale by a 3D printer, the target insulator model being a scaled model of a three-pillar insulator after structural parameter optimization; printing the target insulator model in a scaled-down manner by 3D printing technology, on the one hand avoiding the high cost of metal molds, and scaled printing can further save resources and reduce costs, on the other hand shortening the production cycle of the target insulator model and improving test efficiency, then obtaining a scaled-down test tooling, assembling the target insulator model into the scaled-down test tooling, after obtaining the target test tooling, installing the target test tooling into a power frequency withstand voltage test system; then performing a flashover test on the target insulator model in a step-by-step voltage-boosting manner in the power frequency withstand voltage test system, and after recording the flashover voltage of the target insulator model for a preset number of times during the flashover test, performing a fitting analysis on the recorded flashover voltage to determine the characteristic voltage of the target insulator model, and evaluating the insulation withstand voltage performance of the target insulator model based on the characteristic voltage. By performing a flashover test and recording the flashover voltage of the target insulator model, the insulation withstand voltage performance of the target insulator model can be evaluated. Multiple flashover voltages are recorded to avoid errors to the greatest extent and improve the accuracy of the insulation withstand voltage performance evaluation of the target insulator model.

[0060] In one embodiment, the target insulator model is printed in scale using a 3D printer, including:

[0061] S1: Preparation of filler and base materials.

[0062] The filler is an inorganic material with a high dielectric constant, and the base material is a photosensitive resin material.

[0063] Before printing the target insulator model, the filler and base material are prepared first. Since the function of the base is to meet the requirements of photocuring 3D printing technology, the function of the filler is to increase the dielectric constant of the composite material. Therefore, the filler can be selected from inorganic materials such as nano-alumina, nano-barium titanate or nano-titanium dioxide with high dielectric constant. The base material can be selected from photosensitive resin materials, such as high-temperature resistant epoxy acrylate photosensitive resin, which has a viscosity of about 200MPas at 25°C, contains a photoinitiator, and can be cured under stereoscopic light irradiation (curing wavelength is 405nm). In the above material selection process, the particle size of the filler or the ratio of the filler and the base material can be changed according to actual needs to adjust the relative dielectric constant and other parameters of the three-pillar insulator model. The mixing ratio of the filler and the base material can be determined using the curing thickness test and the rheological properties of the slurry. The preferred volume fraction of alumina filler is 29.6%. At a temperature of 25°C and an industrial frequency voltage (50Hz), the relative dielectric constant can reach 4.2. At this mixing ratio, the final suspension has better processing performance and higher mechanical and thermal conductivity.

[0064] Furthermore, after obtaining the suspension, a broadband dielectric spectrum tester can be used to test the relative dielectric constant and dielectric loss factor of the material, and the test data can be compared with the material test properties of the insulator structure of the scaled model to be printed. In the case of a large difference, the material, ratio, printing parameters and other data can be readjusted.

[0065] S2: Add the filler into the base material in batches, and stir to fully mix the filler and the base material to obtain a mixed suspension.

[0066] In this step, when the filler is added to the base material in batches in small amounts and multiple times, it can be fully stirred after each addition. After the initial suspension is obtained, it can be placed in a magnetic stirrer for further stirring. In this process, anhydride curing agents and accelerators can be used to help the material solidify, and finally a mixed suspension for 3D printing is obtained.

[0067] S3: Defoaming the mixed suspension, and using a 3D printer to scale-print a target insulator model based on the defoamed mixed suspension.

[0068] In this step, the mixed suspension is placed in a vacuum machine for defoaming treatment to ensure the quality of the final model. Then, the model is printed using the defoamed mixed suspension according to the set printing layer thickness and printer light irradiation time. When the target insulator model is printed, the target insulator model can be polished to eliminate possible burrs and detect whether the roughness is within the roughness range of the actual three-pillar insulator structure. If not, it can be further polished. If so, the polished target insulator model can be used as the final target insulator model.

[0069] It is understandable that by using 3D printing technology to print the target insulator model in a reduced scale, on the one hand, the high cost of metal molds is avoided. Once the insulator structural parameters are changed, the corresponding metal molds need to be re-produced, which has low flexibility. In this solution, scaled printing is used to further save resources and reduce costs. On the other hand, the production cycle of the target insulator model can be shortened and the test efficiency can be improved.

[0070] In one embodiment, assembling the target insulator model into a scaled test fixture includes:

[0071] The target insulator model is sleeved on the central conductor in the scaled test fixture to obtain the target test fixture. The scaled test fixture includes a central conductor, a grounding shell and a metal ball. The central conductor is embedded in the grounding shell. Both ends of the central conductor are outside the grounding shell, one end of the central conductor is used to be connected to the high potential end, and the other end is connected to the metal ball.

[0072] In this embodiment, the center conductor, the grounding shell and the metal ball can be produced by CNC machining. In the above-mentioned scaled test fixture, one end of the center conductor can be connected to the high potential end, and the other end can be connected to the metal ball, so as to prevent high voltage discharge at the end, thereby avoiding breakdown discharge of the grounding shell. When the target insulator model is assembled into the scaled test fixture, the metal insert at the leg of the target insulator model can be connected to the grounding shell at a low potential through a metal bolt of a specific size.

[0073] In one embodiment, installing the target test tooling into the power frequency withstand voltage test system includes:

[0074] The target test fixture is placed in a closed test chamber of the power frequency withstand voltage test system, and one end of the central conductor in the target test fixture is connected to the high-voltage bushing in the power frequency withstand voltage test system to connect to the high potential end, and the grounding shell of the target test fixture is grounded.

[0075] In this embodiment, the test fixture assembled with the target insulator model is placed in the closed test chamber of the power frequency withstand voltage test system, and then one end of the central conductor of the target test fixture is connected to the high-voltage bushing to obtain a high potential, and the metal inserts at the legs of the target insulator model can be connected to the grounding shell at a low potential through metal bolts of a specific size, that is, grounding. Through the pre-set power frequency withstand voltage test system, only the target test fixture needs to be assembled and quickly installed on the system, so as to perform a flashover test on the target insulator model, further improving the efficiency of performance evaluation.

[0076] It is understandable that a high-speed camera is provided in the power frequency withstand voltage test system, which can be used to photograph the flashover process, and an observation window is provided on the closed test chamber, and the flashover process can be photographed by placing the high-speed camera in front of the observation window. In one example, the observation window can be made of quartz material.

[0077] In one embodiment, a flashover test is performed on a target insulator model by using a step-by-step voltage step-up method in a power frequency withstand voltage test system, and the flashover voltage of the target insulator model is recorded for a preset number of times during the flashover test, including:

[0078] S1: Fill the closed test chamber of the power frequency withstand voltage test system with gas.

[0079] In this step, the closed test chamber is filled with The gas volume can be adjusted according to actual needs, generally within the range of 0.2-0.4 MPa. In one example, the gas volume can be set to 0.2 MPa.

[0080] S2: In a flashover test, the target test fixture is subjected to multiple step-by-step voltage increases according to a preset voltage increase step length and a preset interval.

[0081] The step length of the voltage boost can be set to 2 kV, and the preset interval can be set to 10 seconds.

[0082] S3: During multiple step-up voltage increases, after recording the flashover voltage of the target insulator model, determine whether the number of records reaches the preset number. If not, enter the next flashover test. If so, obtain the flashover voltage of the target insulator model recorded multiple times.

[0083] Exemplarily, the voltage is increased from a preset initial voltage, with 2kV as the step length, and each voltage increase is maintained for 10 seconds before the next voltage increase, until the target insulator model flashes over, the flashover voltage is recorded, and then the next flashover test is performed, until the preset number of times is reached to obtain multiple flashover voltage data. It should be noted that the target test fixture does not need to be removed after each flashover phenomenon occurs, and the next flashover test can be started after waiting for a certain period of time, for example, waiting for two minutes to perform the next flashover test.

[0084] Specifically, the flashover test is performed and the flashover voltage of the target insulator model is recorded, so as to evaluate the insulation withstand voltage performance of the target insulator model, and multiple flashover voltages are recorded to minimize errors and improve the accuracy of the insulation withstand voltage performance evaluation of the target insulator model.

[0085] In one embodiment, fitting analysis is performed on the recorded flashover voltage to determine the characteristic voltage of the target insulator model, including:

[0086] S1: Determine the probability density function.

[0087] In this step, the distribution to be used can be determined first, and then its corresponding probability density function can be determined. When determining the distribution, the characteristics of different distributions and the actual needs of this solution can be combined. This application does not impose specific restrictions on this.

[0088] S2: A likelihood function is constructed based on the probability density function and the recorded flashover voltage, and the likelihood function is solved to obtain a scale parameter corresponding to the probability density function, which is used as the characteristic voltage of the target insulator model.

[0089] In one embodiment, the probability density function is expressed as:

[0090]

[0091] In the formula, For the The flashover probability of a flashover voltage is For the The voltage value of the flashover voltage, represents the number of recorded flashover voltages, β is the shape parameter, representing the dispersion of the flashover voltage, and α is the scale parameter, representing the voltage value when the flashover probability is the preset probability, that is, the characteristic voltage.

[0092] In one example, the preset probability may be set to 63.2%.

[0093] In one embodiment, evaluating the insulation withstand voltage performance of the target insulator model based on the characteristic voltage includes:

[0094] S1: When comparing and evaluating the insulation withstand voltage performance of the target insulator model, determine the characteristic voltage of the reference insulator model, and compare the characteristic voltage of the target insulator model with the characteristic voltage of the reference insulator model to measure whether the insulation withstand voltage performance of the target insulator is improved; the reference insulator model is a scaled model of a three-pillar insulator before structural parameter optimization.

[0095] S2: When the insulation withstand voltage performance of the target insulator model is evaluated, the performance level corresponding to the characteristic voltage is searched in a preset information table to evaluate the insulation withstand voltage performance of the target insulator model.

[0096] The information table is used to record the corresponding relationship between the characteristic voltage and the performance level. The information table can be preset and adjusted according to actual conditions.

[0097] Specifically, the characteristic voltage of the reference insulator model may be calculated according to a determination method of the characteristic voltage of the target insulator model.

[0098] In this embodiment, when performing comparative evaluation, if the characteristic voltage of the target insulator model is greater than the characteristic voltage of the reference insulator model, it means that the insulation withstand voltage performance of the target insulator model is better than that of the reference insulator model, thereby verifying the optimization effect of the structural parameter optimization. When performing grade evaluation, the insulation withstand voltage performance of the insulator structure corresponding to the target insulator model can be evaluated.

[0099] In one example, if Figure 2 As shown, Figure 2 This is an example diagram of a three-pillar insulator insulation withstand voltage test method provided in an embodiment of the present application. The optimization model refers to the steps of optimizing the printed model such as roughness judgment.

[0100] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0101] The power frequency withstand voltage test system provided in the embodiment of the present application is described below. The power frequency withstand voltage test system described below and the three-pillar insulator insulation withstand voltage test method described above can be referenced to each other.

[0102] like Figure 3 As shown, the present application provides a power frequency withstand voltage test system, the system comprising a transformer 1, a current limiting resistor 2, a resistor-capacitor voltage divider 3, a closed test chamber 4, a high-speed camera 5 and a high-voltage bushing 6;

[0103] The transformer 1 is connected to a first end of a current limiting resistor 2, and a second end of the current limiting resistor 2 is connected to a resistor-capacitor voltage divider 3 and a high-voltage bushing 6 respectively;

[0104] The high-voltage bushing 6 is placed above the closed test chamber 4, and the high-speed camera 5 is placed in front of the observation window 41 of the closed test chamber 4 to shoot the flashover process of the target insulator model;

[0105] The RC voltage divider 3 is used to record the flashover voltage of the target insulator model, and the closed test chamber 4 is used to place the target test fixture 7 to perform a flashover test on the target test fixture 7 .

[0106] In this embodiment, the target test fixture 7 includes a grounding shell 71, a target insulator model 52, a center conductor 73, a metal ball 74 and a grounding metal insert 75 at the leg of the target insulator model.

[0107] In one embodiment, the voltage division ratio of the RC voltage divider is 2000:1.

[0108] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish an entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only include those elements, but also include other elements that are not clearly listed, or also include elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. Herein, the singular "one", "one" and "described / the" may also include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "include / comprise" or "have" etc. specify the existence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the existence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0109] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can refer to each other.

[0110] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three-pillar insulator insulation withstand voltage test method, characterized in that: The method comprises: Printing a target insulator model in scale by a 3D printer, wherein the target insulator model is a scaled model of a three-pillar insulator after structural parameter optimization; Obtaining a scaled-down test fixture, and assembling the target insulator model into the scaled-down test fixture, and after obtaining the target test fixture, installing the target test fixture into a power frequency withstand voltage test system; In the power frequency withstand voltage test system, a flashover test is performed on the target insulator model by adopting a step-by-step voltage-rising method, and the flashover voltage of the target insulator model is recorded for a preset number of times during the flashover test; The recorded flashover voltage is fitted and analyzed to determine the characteristic voltage of the target insulator model, and the insulation withstand voltage performance of the target insulator model is evaluated based on the characteristic voltage.

2. The three-pillar insulator insulation withstand voltage test method according to claim 1, characterized in that: The method of printing the target insulator model in scale by using a 3D printer includes: Prepare a filler and a base material, wherein the filler is an inorganic material with a high dielectric constant, and the base material is a photosensitive resin material; Adding the filler into the base material in batches, and stirring to fully mix the filler and the base material to obtain a mixed suspension; The mixed suspension is subjected to defoaming treatment, and a target insulator model is printed in scale based on the mixed suspension subjected to the defoaming treatment using a 3D printer.

3. The three-pillar insulator insulation withstand voltage test method according to claim 1, characterized in that: The step of assembling the target insulator model into the scaled test fixture comprises: The target insulator model is sleeved on the central conductor in the scaled test fixture to obtain the target test fixture, wherein the scaled test fixture comprises a central conductor, a grounding shell and a metal ball, wherein the central conductor is embedded in the grounding shell, and both ends of the central conductor are outside the grounding shell, wherein one end is used to be connected to a high potential end, and the other end is connected to the metal ball.

4. The three-pillar insulator insulation withstand voltage test method according to claim 1, characterized in that: The step of installing the target test tooling to the power frequency withstand voltage test system comprises: The target test tool is placed in the closed test chamber of the power frequency withstand voltage test system, and one end of the central conductor in the target test tool is connected to the high-voltage bushing in the power frequency withstand voltage test system to connect to the high potential end, and the grounded shell of the target test tool is grounded.

5. The three-pillar insulator insulation withstand voltage test method according to claim 1, characterized in that: The flashover test is performed on the target insulator model in a step-by-step voltage-boosting manner in the power frequency withstand voltage test system, and the flashover voltage of the target insulator model is recorded for a preset number of times during the flashover test, including: Fill the closed test chamber of the power frequency withstand voltage test system with gas; In a flashover test, the target test fixture is subjected to multiple step-by-step voltage boosts according to a preset voltage boost step length and a preset interval; During multiple step-by-step voltage increases, after recording the flashover voltage of the target insulator model, determine whether the number of records reaches the preset number. If not, enter the next flashover test. If so, obtain the flashover voltage of the target insulator model recorded multiple times.

6. The three-pillar insulator insulation withstand voltage test method according to claim 1, characterized in that: The fitting analysis of the recorded flashover voltage to determine the characteristic voltage of the target insulator model includes: Determine the probability density function; A likelihood function is constructed according to the probability density function and the recorded flashover voltage, and the likelihood function is solved to obtain a scale parameter corresponding to the probability density function, and the scale parameter is used as the characteristic voltage of the target insulator model.

7. The three-pillar insulator insulation withstand voltage test method according to claim 6, characterized in that: The probability density function is expressed as: In the formula, For the The flashover probability of a flashover voltage is For the The voltage value of the flashover voltage, represents the number of recorded flashover voltages, β is the shape parameter, representing the dispersion of the flashover voltage, and α is the scale parameter, representing the voltage value when the flashover probability is the preset probability, that is, the characteristic voltage.

8. The three-pillar insulator insulation withstand voltage test method according to claim 1, characterized in that: The evaluating the insulation withstand voltage performance of the target insulator model based on the characteristic voltage includes: When the insulation withstand voltage performance of the target insulator model is compared and evaluated, the characteristic voltage of the reference insulator model is determined, and the characteristic voltage of the target insulator model is compared with the characteristic voltage of the reference insulator model to measure whether the insulation withstand voltage performance of the target insulator is improved; the reference insulator model is a scaled model of a three-pillar insulator before structural parameter optimization; When the insulation withstand voltage performance of the target insulator model is evaluated, the performance level corresponding to the characteristic voltage is searched in a preset information table to evaluate the insulation withstand voltage performance of the target insulator model.

9. A power frequency withstand voltage test system, characterized in that: The system includes a transformer, a current-limiting resistor, a resistor-capacitor voltage divider, a closed test chamber, a high-speed camera and a high-voltage bushing; The transformer is connected to a first end of the current-limiting resistor, and a second end of the current-limiting resistor is connected to the RC voltage divider and the high-voltage bushing respectively; The high-voltage bushing is placed above the closed test chamber, and the high-speed camera is placed in front of the observation window of the closed test chamber to shoot the flashover process of the target insulator model; The RC voltage divider is used to record the flashover voltage of the target insulator model, and the closed test chamber is used to place the target test fixture to perform a flashover test on the target test fixture.

10. The power frequency withstand voltage test system according to claim 9, characterized in that: The voltage division ratio of the RC voltage divider is 2000:1.

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