Porcelain insulator quality evaluation system based on multi-physics field coupling analysis

Abstract

The invention provides a porcelain insulator quality evaluation system based on multi-physics field coupling analysis, and relates to the technical field of rod-column porcelain insulator data processing.The porcelain insulator quality evaluation system adopts an electricity-heat-force multi-physics field joint simulation model to comprehensively reflect the heat accumulation and stress deformation effect caused by electric field concentration; an electric field concentration coefficient, a temperature rise trend coefficient and a stress gradient coefficient at a sharp point can be accurately captured, and degradation path prediction in a real operation environment is formed; according to the technology, the thread coupling abnormal index F alpha i of the ith rod-type column porcelain insulator is constructed, whether the thread structure has the risk of partial discharge, flashover or breakdown or not can be dynamically evaluated, and by introducing equivalent dielectric layer simulation of various environmental media, the simulation of the influence of various pollutants, attachments and climates on electric field concentration in reality is promoted; quantitative evaluation of the corona discharge risk of the sharp point is realized, and the reliability of the structural design of the insulator is promoted and improved.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing for rod - type post porcelain insulators, and specifically to a porcelain insulator quality assessment system based on multi - physical - field coupling analysis. Background Technique

[0002] As an important support and insulation component in power transmission and transformation lines, the structural design and insulation performance of rod - type post porcelain insulators are directly related to the safe and stable operation of the power transmission system. Among them, the threaded connection, as the key fixing structure between the porcelain insulator and the metal end - piece, not only bears long - term mechanical loads but also is an area where the risk of local electric - field distortion is relatively concentrated. In the actual operating environment, due to manufacturing errors, aging and wear, and external stress, small sharp geometric features such as sharp corners, protrusions, and steps often form in the threaded area. These structural feature points are prone to cause the electric - field concentration effect, significantly increasing the local electric - field intensity, thereby inducing partial discharge, corona discharge, and even insulation breakdown. In severe cases, it can lead to the flashover or structural failure of the entire insulator.

[0003] In the prior art, off - line tests or on - site regular infrared temperature measurement, partial - discharge detection, etc. are mostly used to evaluate the state of porcelain insulators. However, most of these methods are based on the overall performance evaluation and are difficult to accurately identify the impact of microscopic sharp structures in the threaded area on the insulation performance. At the same time, traditional analysis means mostly ignore the cross - coupling effect between the electric field, thermal field, and stress field, and cannot predict the potential breakdown risk of the insulator from the perspective of the co - evolution of multi - physical fields. Especially in complex environmental media conditions (such as humid - heat, high - pollution, high - altitude, etc.), the corona - discharge threshold in the threaded area often fluctuates, and the sharp points with electric - field concentration are extremely likely to become the leading discharge sources in such environments. After partial discharge occurs in the threaded area, the thermal effect and mechanical stress can further exacerbate local material aging, micro - crack propagation, and even structural damage, showing a typical "electric - thermal - mechanical" coupling degradation path. The above information disclosed in the background - technique part is only used to strengthen the understanding of the background of the present disclosure, so it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a porcelain insulator quality assessment system based on multi - physical - field coupling analysis to solve the problems mentioned in the background technique.

[0005] The purpose of the present invention is to provide a porcelain insulator quality assessment system based on multi - physical - field coupling analysis to solve the problems raised in the above - mentioned background technique.

[0006] To achieve the above - mentioned purpose, the present invention provides the following technical solutions: A porcelain insulator quality assessment system based on multi - physical - field coupling analysis, comprising: A three-dimensional structure modeling module, which is used to obtain the structural model information of the rod-type post porcelain insulator, establish three-dimensional structure data, and extract the geometric shape information of the threaded end, including pitch, thread depth, and sharp angle characteristic parameters; A multi-physical field coupling simulation module, which is used to perform electric field coupling modeling on the threaded area of the rod-type post porcelain insulator, construct a multi-physical field joint analysis model of electricity-thermal-mechanics, perform local mesh refinement on the threaded area to identify several sharp points, simulate different dielectric environment states, conduct electric field simulation, and obtain the electric field strength value of the j-th sharp point , and simulate the corona discharge threshold range of the electric field tip distribution, and construct the electric field concentration coefficient of the j-th sharp point And evaluate whether there is a risk of sharp point flashover. If so, trigger the first warning instruction. If not, generate the first qualified mark; At the same time, construct the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient , A comprehensive quality prediction module, which is used to construct the threaded coupling anomaly index of the i-th rod-type post porcelain insulator based on the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient , to predict whether there is a breakdown risk in the rod-type post porcelain insulator due to the combined action of electric field, temperature rise and stress, and preset the risk threshold FαY. When is greater than or equal to FαY, output a local breakdown risk mark; when is less than FαY, output the second qualified mark. is less than FαY, output the second qualified mark.

[0007] Furthermore, the three-dimensional structure modeling module includes a structure data input unit and a three-dimensional geometry reconstruction unit; The structure data input unit is used to connect to a three-dimensional laser scanning device and a CAD design drawing to obtain the geometric structure data of the rod-type post porcelain insulator; the geometric structure data includes the structure of the insulator body, the connection fitting area and its threaded end; The three-dimensional geometry reconstruction unit is used to input the collected geometric structure data of the rod-type post porcelain insulator into a modeling engine, perform mesh division and geometric reconstruction, establish a three-dimensional solid model, and identify the threaded end area in the three-dimensional solid model, and automatically extract the thread characteristic parameters: The thread characteristic parameters include: Pitch: The axial distance between two adjacent threads in the threaded area of the porcelain insulator along the spiral direction; Thread depth: The difference between the outer diameter and the bottom diameter of the thread in the threaded area of the porcelain insulator; Thread sharp angle: the tooth profile included angle of each thread cross-section in the thread area of the porcelain insulator, used to judge the sharpness degree.

[0008] Further, the multi-physical-field coupling simulation module includes a finite element analysis unit; The finite element analysis unit is used to construct and train an electric-thermal-mechanical three-field coupling model based on the COMSOL or ANSYS finite element simulation platform; The finite element analysis unit includes an identification unit and an electric field simulation unit: The identification unit is used to collect the curvature of the f-th normal point and the k-th adjacent point in the thread area of the rod-type column porcelain insulator, perform quadratic surface fitting on the f-th normal point and its surrounding k-th adjacent points to obtain a local surface equation, and use the first principal curvature radius of the surface and the second principal curvature radius , which respectively represent the maximum and minimum bending degrees of the surface in two orthogonal directions, and calculate the Gaussian curvature of the f-th normal point and the k-th adjacent point by the following formula : ; Among them, the preset sharp threshold , when and the thread sharp angle is less than the sharp angle threshold, then judge as a sharp point; when , then judge it as not a sharp point; The electric field simulation unit, based on the three-dimensional structure model, determines the connection port of the rod-type column porcelain insulator with the power supply to conduct the first working voltage simulation experiment. Specifically, the first working voltage simulation experiment is as follows: set the applied voltage to 10 kV, that is, the electric potential is 10,000 V; Extract the coordinates of several sharp points obtained by the identification unit to establish a sharp point coordinate set; Record the spatial coordinates of the j-th sharp point in the three-dimensional structure model, expressed as , use a non-contact electrometer or a plasma charge detection device to scan the surface of the sharp area point by point, and output the charge density distribution map. After matching the charge density distribution map with the spatial coordinates of the j-th sharp point, sequentially extract the electric field intensity value of the j-th sharp point .

[0009] The finite element analysis unit also includes a simulated envelope layer area unit and a local corona risk prediction unit; The simulated envelope layer area unit is used to simulate different dielectric environment states to obtain the electric field concentration coefficient of the j-th sharp point ; The relative permittivity of different media specifically includes: When it is dry air, the relative permittivity is set to 1.0006; When it is humid air, the relative permittivity is set to 1.02; When it is rainwater, the relative permittivity is set to 78; When it is acid rain, the relative permittivity is set to 90; When there is dry dust deposition, the relative permittivity is set to 3; When it is a wet dust mixed layer, the relative permittivity is set to 20; When it is an insulating oil pollution layer, the relative permittivity is set to 3; When it is a salt spray coating layer, the relative permittivity is set to 40; When there is plant fiber deposition, the relative permittivity is set to 12; When it is an ice and snow layer, the relative permittivity is set to 4; When it is a contaminated ice layer, the relative permittivity is set to 30; To simulate the influence of environmental attachments on the electric field distribution, the relative permittivity of different media is specified in the envelope layer area near the sharp point surface, equivalent to "covering a dielectric film", and based on the electric field intensity value of the j-th sharp point under this dielectric condition , simulate under the relative permittivity of different media, and through actual measurement and back-calculation, the surface charge density of the j-th sharp point is calculated by the following formula : ; In the formula, represents the relative permittivity in the q-th medium environment, represents the vacuum permittivity, which is set to 8.854×10 −12 F / m; Extract the maximum electric field intensity value of the j-th sharp point , and extract the ratio of the average electric field in the overall insulator main body area , calculate the ratio of the maximum electric field intensity value of the j-th sharp point and the average electric field in the overall insulator main body area to obtain the electric field concentration coefficient of the j-th sharp point .

[0010] Furthermore, the local corona risk prediction unit is used to preset the corona discharge threshold , when the electric field concentration coefficient of the j-th sharp point is greater than the corona discharge threshold, it indicates that there is a corona discharge risk at the j-th sharp point in the q-th medium environment. If there are less than 3 sharp points with electric field concentration coefficients in the i-th rod-type porcelain insulator Exceed the corona discharge threshold , indicating the existence of flashover risk and triggering the first warning instruction, including: Record the electric field concentration data and output the local corona risk mark; If the electric field concentration coefficient of 3 or more sharp points exists in the i-th rod-type post insulator Exceed the corona discharge threshold , indicating that there is a flashover risk caused by local corona discharge in multiple regions and is more serious than the first warning instruction, then trigger the second warning instruction, including: Mark as a non-conforming product; If the electric field concentration coefficient of any sharp point in the i-th rod-type post insulator Does not exceed the corona discharge threshold , generate the first qualified mark.

[0011] Furthermore, the multi-physical field coupling simulation module further includes a thermal analysis unit and a stress analysis unit; The thermal analysis unit is used to use an infrared thermal imager, a thermocouple grid or a fiber optic temperature sensor for the time series temperature map during the first working voltage simulation experiment for the sharp point coordinate set, so as to construct the temperature rise trend coefficient of the j-th sharp point within the sampling time period ; The temperature rise trend coefficient of the j-th sharp point The acquisition method is to extract the temperature value of the j-th sharp point from the time series temperature map and calculate by taking the difference between the temperature change range and the corresponding time period.

[0012] Specifically, ; Represents the maximum temperature of the j-th sharp point within the sampling time period; Represents the maximum temperature of the j-th sharp point within the sampling time period; And Are the times corresponding to the maximum and minimum temperatures; Furthermore, the stress analysis unit is used to use digital image correlation method, photoelastic test device or embedded micro stress sensor for the time series stress distribution map during the first working voltage simulation experiment for the sharp point coordinate set, so as to construct the stress gradient coefficient of the j-th sharp point within the sampling time period ; The stress gradient coefficient of the j-th sharp point The acquisition method is to extract the stress data of the j-th sharp point and its adjacent area from the time series stress map, and calculate the stress gradient coefficient of the j-th sharp point by analyzing the ratio of the stress change amplitude to the corresponding distance change in the spatial neighborhood of the j-th sharp point , so as to reflect the local stress concentration degree of this sharp point.

[0013] Specifically, ; represents the stress value of the j-th sharp point; represents the stress value of the k-th adjacent point adjacent to the j-th point; represents the spatial distance between the j-th sharp point and the k-th adjacent point; If multiple adjacent points are used (such as 3 - 5), the acquisition method of the stress gradient coefficient of the j-th sharp point can be to take the average value: ; M represents the total number of adjacent points; Further, the comprehensive quality prediction module includes an association unit and an anomaly evaluation unit; The association unit is used to extract the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient of the j-th sharp point , after normalization processing, construct the thread coupling anomaly index of the i-th rod-type post insulator , and the expression is as follows: In the formula, N represents the total number of sharp points on the i-th rod-type post insulator; w1, w2 and w3 respectively represent the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient of the j-th sharp point weight values, and their specific values are adjusted and set by the user, and the sum of the weights is 1.

[0014] Further, the anomaly evaluation unit is used to preset the risk threshold FαY, and compare the thread coupling anomaly index of the i-th rod-type post insulator with the risk threshold FαY to obtain the quality evaluation result, including: When is greater than or equal to FαY, it means that this rod-type post insulator has a breakdown risk due to the combined action of electric field, temperature rise and stress, and outputs a local breakdown risk mark; When Less than FαY indicates that the rod - type post porcelain insulator is within a safe range under the combined action of electric field, temperature rise, and stress, indicating stable structure, adapting to different media, and outputting a second qualified mark; After obtaining the first qualified mark and the second qualified mark, it indicates that the rod - type post porcelain insulator is allowed to leave the factory.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Based on the electro - thermal - mechanical multi - physical - field coupling simulation model, the present invention comprehensively reflects the heat accumulation and stress - deformation effects caused by electric - field concentration, can accurately capture the electric - field concentration coefficient, temperature - rise trend coefficient, and stress - gradient coefficient at sharp points, and forms a prediction of the degradation path under the real operating environment. Using the local characteristic data of sharp points, the thread - coupling anomaly index of the i - th rod - type post porcelain insulator is constructed And by setting a preset risk threshold FαY, it can dynamically evaluate the risk of partial discharge, flashover, or breakdown in the thread structure, realize a quantitative and threshold - based quality - assessment process, and avoid the problems of subjective judgment and delayed response in traditional methods.

[0016] In order to simulate the influence of the dielectric layer on the electric - field distribution at sharp points under different natural environments or industrial pollution conditions, the present invention constructs a local envelope - layer area near the surface of sharp points in the thread area and assigns relative permittivity parameters under the following dielectric environments. The above dielectrics are equivalent to "covering a dielectric film", which is simulated to be attached near the thread sharp points to achieve the realistic response of the electric - field distribution under different working conditions. Through the simulation of the equivalent dielectric layer of various environmental dielectrics, this technology can accurately simulate the influence of various pollutions, attachments, and climates on electric - field concentration in reality; it can realize the quantitative assessment of the risk of corona discharge at sharp points, promote the improvement of the reliability of insulator structure design; and provide a basis for supporting subsequent simulation tests for corona - suppression structure optimization or material - coating selection. Brief Description of the Drawings

[0017] Figure 1 It is a schematic flow chart of a porcelain - insulator quality - assessment system based on multi - physical - field coupling analysis according to the present invention. Detailed Embodiment

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] To make the purpose, technical solution, and advantages of the present invention clearer, the following further details the present invention in conjunction with specific embodiments.

[0020] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0021] Embodiment 1: Please refer to Figure 1 , the present invention provides a technical solution: a porcelain insulator quality assessment system based on multi-physical field coupling analysis, including: A three-dimensional structure modeling module, which is used to obtain the structural model information of the rod-type column porcelain insulator, establish three-dimensional structure data, and extract the geometric shape information of the threaded end, including pitch, thread depth and sharp angle characteristic parameters; A multi-physical field coupling simulation module, which is used to perform electric field coupling modeling on the threaded area of the rod-type column porcelain insulator, construct a multi-physical field joint analysis model of electricity-thermal-mechanics, perform local grid refinement on the threaded area to identify several sharp points, simulate different dielectric environment states, perform electric field simulation, and obtain the electric field strength value of the j-th sharp point , and simulate the corona discharge threshold range of the electric field tip distribution, construct the electric field concentration coefficient of the j-th sharp point and evaluate whether there is a risk of sharp point flashover. If so, trigger the first warning instruction. If not, generate the first qualified mark; At the same time, construct the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient , A comprehensive quality prediction module, which is used to construct the threaded coupling anomaly index of the i-th rod-type column porcelain insulator based on the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient , to predict whether there is a breakdown risk in the rod-type column porcelain insulator due to the combined action of electric field, temperature rise and stress, and preset the risk threshold FαY. When , Greater than or equal to FαY, output the local breakdown risk marker; when Less than FαY, output the second qualified marker.

[0022] In this embodiment, through the three-dimensional structure modeling module, the precise reconstruction of the geometric shape of the threaded end of the rod-type post porcelain insulator is realized, providing a geometric basis for the subsequent local electric field enhancement analysis, and helping to comprehensively master the formation position and shape of the sharp points. The system adopts an electro-thermal-mechanical multi-physical field coupling simulation model to comprehensively reflect the heat accumulation and stress deformation effects caused by electric field concentration, and can accurately capture the electric field concentration coefficient, temperature rise trend coefficient and stress gradient coefficient at the sharp points, forming a prediction of the degradation path under the actual operating environment. Based on the local characteristic data of the sharp points, a thread coupling anomaly index is constructed, and a preset risk threshold FαY is set, which can dynamically evaluate the risk of partial discharge, flashover or breakdown in the thread structure, realize a quantitative and threshold-based quality assessment process, and avoid the problems of subjective judgment and delayed response in the traditional method.

[0023] Embodiment 2 This embodiment is an explanatory description based on Embodiment 1. Please refer to Figure 1 , specifically, the three-dimensional structure modeling module includes a structure data input unit and a three-dimensional geometric reconstruction unit; The structure data input unit is used to access a three-dimensional laser scanning device and CAD design drawings to obtain the geometric structure data of the rod-type post porcelain insulator; the geometric structure data includes the insulator body, the connection fitting area and its threaded end structure; The three-dimensional geometric reconstruction unit is used to input the collected geometric structure data of the rod-type post porcelain insulator into the modeling engine, perform mesh division and geometric reconstruction, establish a three-dimensional solid model, and identify the threaded end area in the three-dimensional solid model, and automatically extract the thread feature parameters: The thread feature parameters include: Pitch: The axial distance between two adjacent threads in the threaded area of the porcelain insulator along the helix direction; Thread depth: The difference between the outer diameter and the bottom diameter of the thread in the threaded area of the porcelain insulator; Thread sharp angle: The tooth profile angle of each thread cross-section in the threaded area of the porcelain insulator, used to judge the sharpness.

[0024] In this embodiment, by accessing a three-dimensional laser scanning device and CAD design drawings through the structure data input unit, the system can obtain the geometric structure data of the rod-type post porcelain insulator, realize high-precision modeling of the insulator body, connection fittings and threaded ends, take into account the precise modeling of on-site physical objects and the integration of historical design information, and enhance the accuracy and versatility of the modeling.

[0025] Embodiment 3 This embodiment is an explanatory description carried out in Embodiment 1. Please refer to Figure 1 , specifically, the multi-physical-field coupling simulation module includes a finite element analysis unit; The finite element analysis unit is used to construct and train an electro-thermal-mechanical three-field coupling model based on the COMSOL or ANSYS finite element simulation platform; constructing an electro-thermal-mechanical multi-physical-field coupling model using the COMSOL or ANSYS finite element simulation platform is no longer limited to the analysis of a single electric field distribution, but simultaneously considers the thermal effect and mechanical stress, comprehensively reflecting the evolution process of local deterioration in the thread area under complex operating conditions.

[0026] The finite element analysis unit includes an identification unit and an electric field simulation unit: The identification unit is used to collect the curvature of the f-th normal point and the k-th adjacent point in the thread area of the rod-type post insulator, perform a quadratic surface fitting on the f-th normal point and its surrounding k-th adjacent points to obtain a local surface equation, and use the first principal curvature radius and the second principal curvature radius of this surface, which represent the maximum and minimum bending degrees of the surface in two orthogonal directions respectively, and calculate the Gaussian curvature of the f-th normal point and the k-th adjacent point from the following formula : ; where the preset sharp threshold , when and the thread sharp angle is less than the sharp angle threshold, then judge as a sharp point; when , then judge it as not a sharp point; extract the principal curvature and Gaussian curvature of each normal point and its adjacent point in the thread area through the identification unit to realize the mathematical modeling and quantitative identification of the sharp structure. Compared with traditional visual recognition or empirical estimation, this method can more objectively identify areas with dangerous shapes such as sharp corners or protrusions, effectively avoiding misjudgment and missed judgment.

[0027] The electric field simulation unit, based on the three-dimensional structure model, determines the connection port of the rod-type post insulator to the power supply to conduct a first working voltage simulation experiment. Specifically, the first working voltage simulation experiment is as follows: set the applied voltage to 10 kV, that is, the electric potential is 10,000 V; Extract the coordinates of several sharp points obtained by the identification unit to establish a sharp point coordinate set; Record the spatial coordinates of the j-th sharp point in the three-dimensional structure model, denoted as , a non-contact electrometer or a plasma charge detection device is used to scan the surface of the sharp area point by point and output a charge density distribution map. After matching the charge density distribution map with the spatial coordinates of the j-th sharp point, the electric field strength value of the j-th sharp point is extracted in sequence. .

[0028] By using a non-contact electrometer or a plasma charge detection device to scan the surface of the sharp area, obtaining a charge density distribution map, and precisely matching it with the set of sharp point coordinates identified in the three-dimensional structure, the extraction of the spatial electric field strength value of each sharp point is realized, improving the spatial resolution and quantitative accuracy of electric field distortion detection.

[0029] The finite element analysis unit further includes a simulated envelope layer area unit and a local corona risk prediction unit; The simulated envelope layer area unit is used to simulate different dielectric environment states to obtain the electric field concentration coefficient of the j-th sharp point. ; The relative dielectric constants of different dielectrics specifically include: When it is dry air, it means that the relative humidity is lower than 30% is the dry state, and the relative dielectric constant is set to 1.0006; it is the international standard air value; When it is humid air, it means that the relative humidity is higher than 80% is the humid state, and the relative dielectric constant is set to 1.02; the polarization ability of water vapor in the air increases under high humidity; When it is rainwater, the relative dielectric constant is set to 78, close to the value of pure water; When it is acid rain, the relative dielectric constant is set to 90; because it contains ions (H+, SO42-, etc.), the polarization ability is stronger; When there is dry dust deposition, the relative dielectric constant is set to 3; When there is a wet dust mixed layer, the relative dielectric constant is set to 20; there are conductive channels in the wet dust, with a composite effect; When there is an insulating oil pollution layer, the relative dielectric constant is set to 3; When there is a salt spray covering layer, the relative dielectric constant is set to 40; When there is plant fiber deposition, the relative dielectric constant is set to 12; When there is an ice and snow layer, the relative dielectric constant is set to 4; When there is a contaminated ice layer, the relative dielectric constant is set to 30; there are salts / dust / ionic pollutants in the ice, and the equivalent capacitance increases significantly; The relative permittivity is a ratio that represents the ratio of the dielectric properties of a certain substance in an electric field to the vacuum permittivity of a vacuum. Essentially, it reflects how the propagation ability of the electric field changes in different dielectrics. For different dielectrics, their dielectric properties (i.e., electric field response) vary relative to a vacuum. For example, the relative permittivity of water is 78, indicating that water's response to an electric field is 78 times stronger than that of a vacuum.

[0030] This is because water molecules have a strong polarization ability in an electric field and can store more electrical energy. To simulate the influence of environmental attachments on the electric field distribution, the relative permittivities of different dielectrics are specified for the envelope layer region near the sharp point surface, which is equivalent to "covering a dielectric film", and based on the electric field intensity value of the j-th sharp point under this dielectric condition , through actual measurement and reverse deduction under the relative permittivities of different dielectrics, the surface charge density of the j-th sharp point is calculated using the following formula : ; In the formula, represents the relative permittivity under the q-th dielectric environment, represents the vacuum permittivity, which is set to 8.854×10 −12 F / m; Extract the maximum electric field intensity value of the j-th sharp point, and extract the ratio of the average electric field of the overall insulator main body region . Calculate the ratio of the maximum electric field intensity value of the j-th sharp point to the average electric field of the overall insulator main body region to obtain the electric field concentration coefficient of the j-th sharp point.

[0031] In this embodiment, to simulate the influence of the dielectric layer on the electric field distribution at the sharp point under different natural environments or industrial pollution conditions, a local envelope layer region is constructed near the sharp point surface in the threaded area, and the relative permittivity parameters under the following dielectric environments are given. The above dielectrics are equivalent to "covering a dielectric film", which is simulated to adhere near the threaded sharp point to achieve the realistic response of the electric field distribution under different working conditions. Through the equivalent dielectric layer simulation of multiple environmental dielectrics, this technology can accurately simulate the influence of various pollutions, attachments, and climates on electric field concentration in reality; it can quantitatively evaluate the risk of corona discharge at the sharp point, greatly improving the reliability of insulator structure design; it supports providing a basis for subsequent simulation tests on corona suppression structure optimization or material coating selection.

[0032] Example 4 This embodiment is an explanatory description based on Example 1. Please refer to Figure 1, specifically, the local corona risk prediction unit is used to preset the corona discharge threshold , when the electric field concentration coefficient of the j-th sharp point is greater than the corona discharge threshold , it indicates that the j-th sharp point has a corona discharge risk in the q-th dielectric environment. If there are less than 3 sharp points in the i-th rod-type post insulator whose electric field concentration coefficients exceed the corona discharge threshold , it indicates a flashover risk and triggers the first warning instruction, including: Record the electric field concentration data and output the local corona risk mark; If there are 3 or more sharp points in the i-th rod-type post insulator whose electric field concentration coefficients exceed the corona discharge threshold , it indicates that there is a flashover risk caused by local corona discharge in multiple regions and is more serious than the first warning instruction, then trigger the second warning instruction, including: Mark it as a non-conforming product; If the electric field concentration coefficient of any sharp point in the i-th rod-type post insulator does not exceed the corona discharge threshold , generate the first qualified mark.

[0033] In this embodiment, if in the i-th rod-type post insulator, there are less than 3 sharp points whose electric field concentration coefficients exceed the corona discharge threshold , it is determined that the insulator has a risk of flashover caused by local corona discharge and triggers the first warning instruction. The first warning instruction includes: Record the electric field concentration coefficient data of all sharp points of the i-th porcelain insulator; Output the coordinates of the sharp points with corona discharge risk and the electric field concentration values; Generate the local corona risk mark.

[0034] If in the i-th rod-type post insulator, there are 3 or more sharp points whose electric field concentration coefficients exceed the corona discharge threshold , it is determined that there is a corona aggregation discharge behavior in multiple regions of the insulator, significantly increasing the overall flashover probability, and triggering the second warning instruction. The second warning instruction includes: Mark the porcelain insulator as a non-conforming product; Output the reason for the non-conforming judgment and the risk coordinate set of the corresponding sharp points.

[0035] In this embodiment, by identifying sharp points, calculating their electric field concentration coefficients, and setting the corona discharge threshold, accurate prediction of local corona discharge and flashover risks of rod-type post insulators under different dielectric contamination states is achieved, improving the intelligence and reliability of insulator quality assessment and providing a basis for their production screening, operation, and maintenance.

[0036] Embodiment 5 This embodiment is an explanatory description carried out in Embodiment 1. Please refer to Figure 1 , specifically, the multi-physical field coupling simulation module further includes a thermal analysis unit and a stress analysis unit; The thermal analysis unit is used to use an infrared thermal imager, a thermocouple grid, or an optical fiber temperature sensor to obtain the time-series temperature map of the sharp point coordinate set during the first working voltage simulation experiment, so as to construct the temperature rise trend coefficient of the j-th sharp point within the sampling time period ; The temperature rise trend coefficient of the j-th sharp point is obtained by extracting the temperature value of the j-th sharp point from the time-series temperature map and calculating the difference between the temperature change range and the corresponding time period.

[0037] Specifically, ; represents the maximum temperature of the j-th sharp point within the sampling time period; represents the maximum temperature of the j-th sharp point within the sampling time period; and are the times corresponding to the maximum and minimum temperatures; In this embodiment, the larger the temperature rise trend coefficient of the j-th sharp point, the higher the electro-thermal coupling intensity of this sharp point and the higher the risk of heat generation. By constructing the time-series temperature map of the sharp point under the applied working voltage and quantifying its temperature rise trend coefficient, it helps to judge whether there is high-energy accumulation in the local abnormal area from the perspective of the thermal field, thus improving the prediction accuracy of local corona or thermal breakdown risks.

[0038] Embodiment 6 This embodiment is an explanatory description carried out in Embodiment 1. Please refer to Figure 1 , specifically, the stress analysis unit is used to use digital image correlation method, photoelastic test device, or embedded micro stress sensor to obtain the time-series stress distribution map of the sharp point coordinate set during the first working voltage simulation experiment, so as to construct the stress gradient coefficient of the j-th sharp point within the sampling time period ; The stress gradient coefficient of the j-th sharp point The acquisition method is to extract the stress data of the j-th sharp point and its adjacent area from the time series stress map, and calculate the stress gradient coefficient of the j-th sharp point by analyzing the ratio of the stress change amplitude to the corresponding distance change in the spatial neighborhood of the j-th sharp point, so as to reflect the local stress concentration degree of the sharp point. to reflect the local stress concentration degree of the sharp point.

[0039] Specifically, ; represents the stress value of the j-th sharp point; represents the stress value of the k-th adjacent point adjacent to the j-th point; represents the spatial distance between the j-th sharp point and the k-th adjacent point; If multiple adjacent points (such as 3 - 5) are used, the acquisition method of the stress gradient coefficient of the j-th sharp point can be to take the average value: ; M represents the total number of adjacent points; In this embodiment, by performing micro-scale gradient analysis on the stress distribution of the sharp point and its adjacent area, the stress concentration degree under the electro-thermal effect can be quantified, providing a basis for identifying physical failure risks such as cracks and breakdowns that may be caused by local structural distortion or stress coupling, and improving the reliability and forward-looking of systematic failure prediction.

[0040] Embodiment 7 This embodiment is an explanatory description carried out in Embodiment 1. Please refer to Figure 1 , specifically, the comprehensive quality prediction module includes an association unit and an anomaly evaluation unit; The association unit is used to extract the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient of the j-th sharp point , after normalization, construct the thread coupling anomaly index of the i-th rod-type porcelain insulator through weighting , and the expression is as follows: In the formula, N represents the total number of sharp points on the i-th rod-type porcelain insulator; w1, w2 and w3 respectively represent the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient of the j-th sharp point weight values, and their specific values are adjusted and set by the user, and the sum of the weights is 1.

[0041] The abnormal evaluation unit is configured to preset a risk threshold FαY and use the screw coupling abnormal index of the i-th rod-type porcelain insulator to compare with the risk threshold FαY to obtain a quality evaluation result, including: When is greater than or equal to FαY, it indicates that the rod-type porcelain insulator has a breakdown risk due to the combined action of electric field, temperature rise and stress, and outputs a local breakdown risk mark; When is less than FαY, it indicates that the rod-type porcelain insulator is in a safe range under the combined action of electric field, temperature rise and stress, indicating stable structure and adaptability to different media, and outputs a second qualified mark; After obtaining the first qualified mark and the second qualified mark, it indicates that the rod-type porcelain insulator is allowed to leave the factory.

[0042] In this embodiment, the present invention can comprehensively identify potential breakdown risks caused by electric field distortion, thermal stress superposition and structural micro-damage by introducing a weighted fusion and dynamic evaluation mechanism of multi-physical field indicators; improve the quality screening accuracy and early failure identification ability of rod-type porcelain insulators, realize high-reliability insulator factory control, help reduce the failure rate during operation, and enhance the environmental adaptability and long-term stability of products.

[0043] The setting of the threshold value is for the convenience of comparison. Regarding the size of the threshold value, it depends on the amount of sample data and the base quantity set by those skilled in the art for each group of sample data; as long as it does not affect the proportional relationship between the parameters and the quantified values.

[0044] It should be noted that: all calculation formulas in this application document adopt, including but not limited to, regression analysis in machine learning algorithms to deeply analyze the relevant parameters collected, identify their natural trends and mutual relationships. Use professional software, such as the Scikit-learn library of Python or the R language, to automatically generate a mathematical model that matches the data. Then, objectively evaluate the performance of the model through methods such as cross-validation, and combine continuous feedback and optimization to ensure that the created formula truly reflects the internal laws of the data, thereby ensuring its effectiveness and accuracy, and ensuring that the calculation process conforms to the constraints of natural laws, rather than being based on artificially set rules.

[0045] The technical solution of the present invention can be embodied in the form of a software product in essence or in the part that contributes to the prior art. This computer software product can be stored in a computer-readable storage medium, such as a floppy disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk, or an optical disc of a computer, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of various embodiments of the present invention.

[0046] The logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in combination with an instruction execution system, apparatus, or device.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention, and all of them should be covered by the scope of the claims of the present invention.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention, and all of them should be covered by the scope of the claims of the present invention.

Claims

1. A porcelain insulator quality assessment system based on multi-physical field coupling analysis, characterized in that It includes the following steps: A three-dimensional structure modeling module, which is used to obtain the structural model information of the rod-type porcelain insulator, establish three-dimensional structure data, and extract the geometric shape information of the threaded end, including pitch, thread depth, and sharp angle characteristic parameters; The multi-physical field coupling simulation module is used to perform electric field coupling modeling on the threaded area of the rod-type post porcelain insulator, construct an electro-thermal-mechanical multi-physical field joint analysis model, refine the local grid in the threaded area to identify several sharp points, simulate different dielectric environmental states, perform electric field simulation, and obtain the electric field intensity value of the j-th sharp point , and simulate the corona discharge threshold range of the electric field tip distribution to construct the electric field concentration coefficient of the j-th sharp point And evaluate whether there is a risk of sharp point flashover. If so, trigger the first warning instruction. If not, generate the first qualified mark; Construct the temperature rise trend coefficient of the j-th sharp point simultaneously and the stress gradient coefficient , Comprehensive quality prediction module for electric field concentration factor based on the jth sharp point , the temperature rise trend coefficient of the jth sharp point and stress gradient coefficient , construct the thread coupling anomaly index of the i-th rod-type column porcelain insulator , in order to predict whether the rod-type column porcelain insulator has a breakdown risk due to the combined effects of electric field, temperature rise and stress, and preset the risk threshold FαY. Greater than or equal to FαY, output local breakdown risk mark; when If it is less than FαY, a second qualified flag is output.

2. The porcelain insulator quality evaluation system based on multi-physical field coupling analysis according to claim 1, characterized in that: The three-dimensional structure modeling module includes a structure data input unit and a three-dimensional geometric reconstruction unit; The structure data input unit is used to access a three-dimensional laser scanning device and a CAD design drawing to obtain the geometric structure data of the rod-type porcelain insulator; the geometric structure data includes the insulator body, the connection fitting area, and the structure of its threaded end; The three-dimensional geometric reconstruction unit is used to input the collected geometric structure data of the rod-type porcelain insulator into a modeling engine, perform mesh division and geometric reconstruction, establish a three-dimensional solid model, and identify the threaded end area in the three-dimensional solid model to automatically extract the thread characteristic parameters: The thread characteristic parameters include: Pitch: The axial distance between two adjacent threads along the helix direction in the thread area of the porcelain insulator; Thread depth: The difference between the outer diameter and the bottom diameter of the thread in the thread area of the porcelain insulator; Thread sharp angle: The tooth profile angle of each thread cross-section in the thread area of the porcelain insulator to judge the sharpness.

3. The porcelain insulator quality assessment system based on multi-physical field coupling analysis according to claim 2, characterized in that: The multi-physics field coupling simulation module includes a finite element analysis unit; The finite element analysis unit is used to construct and train an electric-thermal-mechanical three-field coupling model based on the COMSOL or ANSYS finite element simulation platform; The finite element analysis unit includes an identification unit and an electric field simulation unit: The recognition unit is used to collect the curvature of the f-th normal point and the k-th adjacent point in the threaded area of the rod-type post insulator, perform quadratic surface fitting on the f-th normal point and its surrounding k-th adjacent points to obtain a local surface equation, and obtain the first principal curvature radius of the surface and the second principal curvature radius , which represent the maximum and minimum bending degrees of the surface in two orthogonal directions respectively, and the Gaussian curvature of the f-th normal point and the k-th adjacent point is calculated by the following formula : ； Among them, the preset sharp threshold , when and the thread sharp angle is less than the sharp angle threshold, it is determined that is a sharp point; when , it is determined that is not a sharp point; The electric field simulation unit, based on the three-dimensional structure model, determines the connection port of the rod-type porcelain insulator to the power supply to conduct a first working voltage simulation experiment. Specifically, the first working voltage simulation experiment is as follows: Set the applied voltage to 10 kV, that is, the electric potential is 10,000 V; Extract the coordinates of several sharp points obtained by the identification unit to establish a sharp point coordinate set; Record the spatial coordinates of the j-th sharp point in the three-dimensional structure model, denoted as , use a non-contact electrometer or a plasma charge detection device to scan the surface of the sharp area point by point, and output the charge density distribution map. After matching the charge density distribution map with the spatial coordinates of the j-th sharp point, sequentially extract the electric field strength value of the j-th sharp point .

4. The porcelain insulator quality evaluation system based on multi-physical field coupling analysis according to claim 3, characterized in that: The finite element analysis unit also includes a simulated envelope layer area unit and a local corona risk prediction unit; The simulated envelope layer region unit is used to simulate different medium environmental states to obtain the electric field concentration coefficient of the j-th sharp point ; The relative permittivity of different dielectrics specifically includes: When it is dry air, the relative permittivity is set to 1.0006; When it is humid air, the relative permittivity is set to 1.02; When it is rainwater, the relative permittivity is set to 78; When it is acid rain, the relative permittivity is set to 90; When there is dry dust deposition, the relative permittivity is set to 3; When there is a wet dust mixed layer, the relative permittivity is set to 20; When there is an insulating oil pollution layer, the relative permittivity is set to 3; When there is a salt spray covering layer, the relative permittivity is set to 40; When there is plant fiber deposition, the relative permittivity is set to 12; When there is an ice and snow layer, the relative permittivity is set to 4; When there is a contaminated ice layer, the relative permittivity is set to 30; To simulate the influence of environmental attachments on the electric field distribution, the relative permittivities of different dielectrics are specified in the envelope layer region near the surface of the sharp points, which is equivalent to "covering a dielectric film", and based on the electric field intensity value of the j-th sharp point under this dielectric condition , to simulate the surface charge density of the j-th sharp point obtained by calculation through the following formula by actual measurement inversion under the relative permittivities of different dielectrics :[[]]END]] ； In the formula, represents the relative permittivity in the q-th medium environment, represents the permittivity of vacuum, which is set to 8.854×10 −12 F / m; Extract the maximum electric field intensity value of the j-th sharp point , and extract the ratio of the average electric field of the overall insulator main body area , calculate the maximum electric field intensity value of the j-th sharp point and the ratio of the average electric field of the overall insulator main body area , and obtain the electric field concentration coefficient of the j-th sharp point .

5. A porcelain insulator quality assessment system based on multi-physical field coupling analysis according to claim 4, characterized in that: The local corona risk prediction unit is used to preset the corona discharge threshold , when the electric field concentration coefficient of the j-th sharp point is greater than the corona discharge threshold , it indicates that there is a corona discharge risk at the j-th sharp point in the q-th dielectric environment. If there are less than 3 sharp points in the i-th rod-type post insulator whose electric field concentration coefficients exceed the corona discharge threshold , it indicates that there is a flashover risk and triggers the first warning instruction, including: Record the electric field concentration data and output a local corona risk mark; If the electric field concentration factor of three or more sharp points exists in the i-th rod-type porcelain insulator exceeds the corona discharge threshold , indicating that there are flashover risks caused by local corona discharge in multiple areas and is more serious than the first warning instruction, then the second warning instruction is triggered, including: marking as unqualified products; If the electric field concentration factor at any sharp point within the i-th rod-type post insulator does not exceed the corona discharge threshold , a first qualified mark is generated.

6. The quality assessment system for porcelain insulators based on multi-physical field coupling analysis according to claim 3, characterized in that: The multi-physics field coupling simulation module also includes a thermal analysis unit and a stress analysis unit; The thermal analysis unit is used to construct the temperature rise trend coefficient of the j-th sharp point within the sampling time period based on the time series temperature maps of the sharp point coordinate set during the first working voltage simulation experiment using an infrared thermal imager, a thermocouple grid, or an optical fiber temperature sensor. ; The temperature rise trend coefficient of the j-th sharp point is obtained by extracting the temperature value of the j-th sharp point from the time series temperature map and calculating the difference between the temperature change range and the corresponding time period.

7. The porcelain insulator quality assessment system based on multi-physical field coupling analysis according to claim 6, characterized in that: The stress analysis unit is used to construct the stress gradient coefficient of the j-th sharp point within the sampling time period for the time series stress distribution map of the sharp point coordinate set during the simulation experiment of the first working voltage by using the digital image correlation method, the optoelectronic test device or the embedded micro stress sensor. ; The stress gradient coefficient of the j-th sharp point is obtained by extracting the stress data of the j-th sharp point and its adjacent region from the time-series stress map, and calculating the stress gradient coefficient of the j-th sharp point by analyzing the ratio of the stress change amplitude to the corresponding distance change in the spatial neighborhood of the j-th sharp point to reflect the local stress concentration degree of the sharp point 8. The porcelain insulator quality assessment system based on multi-physical field coupling analysis according to claim 7, characterized in that: The comprehensive quality prediction module includes an associated unit and an abnormality evaluation unit; The associated unit is used to extract the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point and the stress gradient coefficient of the j-th sharp point . After normalization, the abnormal index of thread coupling of the i-th rod-type porcelain insulator is constructed by weighting . The expression is as follows: In the formula, N represents the total number of sharp points on the i-th rod-type porcelain insulator; w1, w2, and w3 respectively represent the electric field concentration coefficient of the j-th sharp point , the temperature rise trend coefficient of the j-th sharp point , and the stress gradient coefficient of the j-th sharp point The weight values, whose specific values are adjusted and set by the user, and the sum of the weights is 1.

9. The porcelain insulator quality assessment system based on multi-physical field coupling analysis according to claim 8, wherein: The abnormal evaluation unit is used to preset a risk threshold FαY and compare the thread coupling abnormal index of the i-th rod-type porcelain insulator with the risk threshold FαY to obtain a quality evaluation result, including: When is greater than or equal to FαY, it indicates that there is a breakdown risk for this rod-type post porcelain insulator due to the combined action of electric field, temperature rise and stress, and a local breakdown risk mark is output; When is less than FαY, it indicates that the rod-type post porcelain insulator is within the safe range under the combined action of electric field, temperature rise and stress, indicating stable structure, adapting to different media, and outputting the second qualified mark; After obtaining the first qualified mark and the second qualified mark, it means that the rod-type porcelain insulator is allowed to leave the factory.

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