Disc-shaped suspension insulator voltage balance control method

Abstract

The invention discloses a voltage balance control method for a disc-shaped suspension insulator, and particularly relates to the field of power systems, and the method comprises the steps: carrying out the simulation calculation of the electric field distribution of an insulator string through finite element simulation software, and obtaining the voltage and electric field distribution conditions of the insulator string when a classification ring is not installed; electric field simulation analysis is carried out by establishing a simulation model of the insulator string and the grading rings, and the diameter, height and relative position of each grading ring are iteratively adjusted; the grading ring is fixed at the axial position of the insulator string; and nano-scale particles are added into the insulating material matrix. The insulation reliability of the insulator is improved, the service life of the insulator is prolonged, and meanwhile the voltage distribution coefficient of each insulator unit tends to be balanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, and more particularly, relates to a voltage equalization control method for a disc-type suspension insulator. BACKGROUND

[0002] The disc-type suspension insulator is widely used in the suspension support of a power transmission line due to its simple structure, easy installation and convenient maintenance.

[0003] The existing publication 1 (Optimization Analysis of Steel Foot Structure of Cylinder Head Disc Suspension Porcelain Insulator, 2022) discloses a method for optimizing the steel foot structure of a disc-type suspension porcelain insulator. The method takes a certain type of 120kN cylinder head porcelain insulator as the object, selects five key parameters of the total height (D1), total width (D3), root arc radius (R1), middle arc radius (R2) and top arc radius (R3) of the steel foot head, establishes a parameterized fine simulation model, and simulates the stress and strain distribution under the rated load based on the linear elastic material assumption and the solid mechanics equation. However, this method does not consider the unevenness of the voltage distribution in the insulator string, which causes the insulator near the conductor end to bear higher voltage stress and easily produce the phenomenon of excessively high local electric field.

[0004] The existing publication 2 (Influence of Live Icing Process on Icing and Electric Field Characteristics of Disc-Type Suspension Insulator, 2010) discloses an insulator icing calculation model. The model uses the finite element method (FEM) to establish a two-dimensional symmetric model of the disc-type suspension insulator under different icing conditions, and performs simulation calculation through COMSOL software. The modeling process considers the insulator structure size, electrical boundary conditions and icing medium characteristics, while ignoring the influence of the conductor, water droplets, airflow, corona discharge, local arc and leakage current. However, this model does not consider that the insulator unit near the power transmission conductor end bears higher voltage due to the influence of the parasitic capacitance, resulting in excessive electric field strength and leading to degradation of insulation performance.

[0005] Therefore, there is an urgent need for a voltage equalization control method that can achieve uniform voltage distribution of the disc-type suspension insulator and improve the insulation reliability and service life. SUMMARY

[0006] In order to overcome the above-mentioned defects of the prior art, the present application provides a voltage equalization control method for a disc-type suspension insulator, which analyzes the electric field distribution, optimizes the diameter, height and position of the grading ring, makes the voltage distribution coefficient of each insulator unit tend to be balanced, and then iteratively adjusts the parameters of the grading ring and combines the performance of the nano-particle reinforced insulating material to improve the service life of the insulator, thereby solving the problems raised in the above background.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A disc-shaped suspension insulator voltage equalization control method, comprising the following steps:

[0009] Step S1, simulating and calculating the electric field distribution of the insulator string, obtaining the voltage and electric field distribution of the insulator string when the grading ring is not installed, and establishing a three-dimensional simulation model by using finite element simulation analysis software;

[0010] Step S2, performing electric field simulation analysis, and iteratively adjusting the diameter, height and relative position of each grading ring;

[0011] Step S3, fixing the grading ring at the axial position of the insulator string;

[0012] Step S4, adding nano-sized particles to the insulating material matrix;

[0013] In the step S2, the three-dimensional simulation model is subjected to voltage and electric field distribution calculation to obtain the electric field intensity, potential distribution and voltage gradient parameters inside and outside the grading ring and the insulator string; taking the above as input, the voltage and electric field distribution borne by each insulator unit are analyzed, the area with uneven voltage distribution is identified, and parameter iterative optimization is entered:

[0014] Step Z1, minimizing the voltage distribution coefficient deviation as the objective function;

[0015] Step Z2, taking the diameter, cross-sectional area, installation height of each grading ring and the relative position between the grading ring and the insulator body as parameters, and adjusting the axial suspension height position of the grading ring;

[0016] Step Z3, inputting the above parameters into the finite element simulation platform for finite element simulation;

[0017] Step Z4, analyzing the simulation output, if the voltage distribution area is uniform and the voltage distribution coefficient error of each disc is <±10%, the current parameters are judged as “preliminary convergence”; otherwise, according to the deviation direction of the voltage distribution, the parameters are adjusted so that the voltage distribution coefficient error of each disc is <±10%;

[0018] Step Z5, outputting the final optimized parameter results, simulation atlas and voltage distribution coefficient statistical table.

[0019] In the step Z2, the axial suspension height of the grading ring refers to the installation position in the longitudinal direction of the insulator string, which is defined by the vertical distance between the ring core and the uppermost end of the insulator string. The process of adjusting the axial suspension height position of the grading ring is dynamically performed in combination with the feedback data of the finite element simulation. The electric field intensity nephogram and the voltage distribution coefficient are recalculated after each change of height until the grading ring voltage coefficient deviation is less than ±10%.

[0020] In step Z3, in the finite element simulation platform, a three-dimensional geometric model is constructed, after modeling, the finite element grid is divided, and the grid density is increased near the insulator surface, the umbrella skirt edge and the grading ring; the boundary conditions are set: the conductor end is applied with rated AC voltage, the tower body and support are set as the ground boundary with potential of 0, and the air area is set as the non-reflective electromagnetic boundary; after completing the boundary setting, the electrostatic field simulation module is started to solve; after the simulation is completed, the potential difference of the two ends of each insulator is output, the corresponding voltage distribution coefficient is calculated, and the electric field strength cloud map, the voltage potential surface distribution map and the axial potential curve map are generated.

[0021] In step Z4, according to the deviation direction of the voltage distribution, the specific steps of adjusting the parameters are as follows: if the voltage distribution coefficient of the first or second insulator exceeds 10%-20% or more than the ideal uniform voltage distribution value in the simulation, it indicates that the first-stage grading ring has different electric field shielding effect on the conductor end, the diameter of the grading ring is adjusted from 800mm to 1000mm to expand its potential equivalent surface and enhance its suppression ability to the edge electric field line; if the high voltage appears in the middle, a new first-stage grading ring is added to extend the voltage distribution coverage to the tower end; after each parameter adjustment, the simulation is verified to improve the voltage distribution, and the voltage distribution coefficient of each insulator is gradually averaged to achieve the target of voltage difference within ±10% of each disc.

[0022] As a further scheme of the application, in step S1, the insulator string electric field distribution simulation calculation is performed to obtain the voltage and electric field distribution of the insulator string without installing the grading ring, a three-dimensional simulation model is established by using finite element simulation analysis software, including the following specific contents: according to the voltage grade of the transmission line, the actual working environment and requirements of the insulator string are analyzed and defined, and the specific structure parameters of the multi-stage grading ring are preliminarily set according to the line voltage grade, operation condition and safety requirement. The structure parameters include the number of grading rings, the diameter size of the ring body, the preliminary value of the cross-sectional area of the ring body, and the axial suspension height range of each stage grading ring relative to the insulator body.

[0023] After the preliminary determination of the structural parameters is completed, a three-dimensional simulation model is established using finite element simulation analysis software. First, typical structural components such as power transmission conductors, insulator strings, towers, and ground are constructed in the simulation software, and the material properties, electrical parameters, and geometric dimensions of each unit in the insulator string are clearly marked to ensure that the model accurately reflects the actual line operating state. Subsequently, the corresponding boundary conditions are input into the simulation model, including the line voltage level, the actual operating current of the power transmission conductor, the grounding condition, the surrounding environmental capacitance parameters, and the setting of the solution domain boundary and boundary conditions. After the simulation begins, the software calculates the potential, voltage distribution, electric field strength, and electric potential gradient of the entire insulator string and each unit insulator under the condition of not installing any stepped ring. Through simulation calculation, the voltage distribution differences at various positions in the insulator string can be identified.

[0024] As a further scheme of the present application, step S2, an electric field simulation analysis is performed to iteratively adjust the diameter, height, and relative position of each stepped ring, including the following specific contents: based on the above-mentioned three-dimensional simulation model, the rated voltage of the actual power transmission line is applied to the conductor, and the electrical boundary conditions of the ground and tower are determined, and then the finite element analysis software is used to calculate the voltage and electric field distribution of the simulation model to obtain detailed parameter information including the electric field strength, potential distribution, and voltage gradient of the stepped ring and the interior and surface of the insulator string.

[0025] The specific electric field parameters obtained through simulation analysis are used as input information to analyze and obtain the voltage borne by each insulator unit, the voltage gradient between each disc, and the electric field strength distribution map. According to the simulation results, the areas of uneven voltage distribution in the insulator string are identified, and the parameter iterative optimization phase is entered.

[0026] As a further scheme of the present application, step S3, the stepped ring is fixed at the axial position of the insulator string, including the following specific contents: the optimized stepped ring is made of an aluminum alloy material with excellent electrical conductivity and strong corrosion resistance, which has high electrical conductivity and good mechanical strength and can operate for a long time in high-voltage, atmospheric exposure, high-humidity, and polluted environments without failure. The main body of the stepped ring is in a ring structure, and the inner diameter is designed to be slightly larger than the maximum outer diameter of the insulator body. Clamping components are provided on both sides of the ring body for fixation.

[0027] A multi-stage stepped ring adjustable suspension device is used to adjust the position of the ring body, which includes an insulating adjusting rod and a ring-shaped clamping mechanism. One end of the adjusting rod is fixed to the insulator umbrella skirt structure, and the other end is connected to the ring-shaped clamping mechanism through a threaded interface. By rotating the threads or replacing different hole positions, the installation personnel can achieve fine adjustment of the stepped ring in the vertical direction, with an adjustment range of ±50mm to ±150mm, meeting the needs of on-site voltage distribution fine correction.

[0028] As a further scheme of the present application, the step S4 of adding nano-particles into the insulating material matrix comprises the following specific contents: selecting ceramic matrix powder with high strength and high insulation performance, including alumina and magnesium oxide. Nano-particles with high dielectric constant are introduced in a proportion of 2% to 5%. Through the disturbance of the nano-particles to the electric field lines in the micro scale, a micro "electric potential buffer zone" can be formed in the overall material, effectively reducing the risk of local electric field concentration. In order to ensure the sufficient mixing of the ceramic powder and the nano-particles and achieve nano-scale dispersion, high-energy ball milling technology is used for mixing treatment. The high-energy ball milling technology homogenizes the powder with different particle sizes and properties in a short time through mechanical energy to form a uniform mixture. The ball milling time is controlled to be more than 12 hours. After the mixing is completed, the nano-composite ceramic powder is put into a high-precision metal mold for high-pressure pressing forming. The cold isostatic pressing is used in the pressing process, and the pressure is applied between 150 MPa and 300 MPa, so that the powder particles are densely packed in the mold cavity, and a green body with structural strength is preliminarily formed. Next, the formed body is placed in a high-temperature sintering furnace for sintering and solidification treatment. The sintering process is carried out in an atmosphere-controlled manner, the temperature is set to be between 1250°C and 1450°C, and the heating rate is controlled to be 35°C / min to avoid micro-cracks or uneven sintering caused by rapid thermal expansion. The sintering holding time is 24 hours, during which the material undergoes solid-phase reaction, grain rearrangement and densification process, and finally forms a composite ceramic body with excellent dielectric properties and structural integrity. Finally, in order to enhance the anti-fouling, moisture resistance and weather resistance of the insulator, a layer of high-performance silicone rubber coating is covered on the outer surface of the insulator body. The coating uses liquid silicone rubber material, which is applied by spraying, brushing or dipping, and is formed into a solid cover layer by room temperature or high temperature vulcanization. The thickness of the coating is controlled to be between 0.5 and 1.5 mm.

[0029] The technical effects and advantages of the disc-shaped suspension insulator voltage equalization control method of the present application are as follows: through finite element simulation analysis and optimization design, the present application realizes the equalization control of the voltage distribution of the insulator string, effectively solves the phenomenon that the insulators near the conductor end bear higher voltage stress due to uneven voltage distribution of the disc-shaped suspension insulator string, and easily produces local electric field that is too high. The present application adjusts the parameters of the grading ring iteratively and combines the nano-particle reinforced insulating material performance to improve the insulation reliability and service life of the insulator. Specifically, the method uses finite element simulation software to accurately analyze the electric field distribution, optimizes the diameter, height and position of the grading ring, makes the voltage distribution coefficient of each insulator unit tend to be balanced, and adds nano-particles to improve the anti-fouling, moisture resistance and weather resistance of the material. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The flow chart of the disc-shaped suspension insulator voltage equalization control method of the present application.

[0031] Figure 2 A schematic diagram of a simulation model of a cylindrical head porcelain insulator of the prior art.

[0032] Figure 3 A schematic diagram of a calculation model of an icing insulator of the prior art.

[0033] Figure 4 A comparative curve graph of voltage distribution of an insulator string before and after optimization of the present application.

[0034] Figure 5 A histogram of voltage distribution coefficient of each disc insulator of the present application.

[0035] Figure 6 An adjustable suspension device of a multi-stage grading ring of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0037] Embodiment 1

[0038] The embodiment of the present application provides a disc suspension insulator voltage equalization control method, which comprises the following steps:

[0039] Step S1, electric field distribution simulation calculation of an insulator string is performed to obtain the voltage and electric field distribution of the insulator string when no grading ring is installed, and a three-dimensional simulation model is established by using finite element simulation analysis software.

[0040] Step S2, electric field simulation analysis is performed, and the diameter, height and relative position of each grading ring are iteratively adjusted.

[0041] Step S3, the grading ring is fixed at the axial position of the insulator string.

[0042] Step S4, nano-level particles are added to the insulator material matrix.

[0043] In the embodiment, reference is made to Figure 2A method for optimizing the structure of a steel foot of a disc-type suspension porcelain insulator is disclosed in the prior art. The method takes a certain type of 120 kN cylindrical head porcelain insulator as the object, selects five key parameters of the total height (D1), total width (D3), root arc radius (R1), middle arc radius (R2), and top arc radius (R3) of the steel foot head, establishes a parameterized fine simulation model, and simulates the stress and strain distribution under the rated load based on the linear elastic material assumption and the solid mechanics equation. However, this method does not consider the uneven voltage distribution in the insulator string, which causes the insulator near the conductor end to bear higher voltage stress and easily produce the phenomenon of excessively high local electric field. See Figure 3 An insulator icing calculation model is disclosed in the prior art. The model uses the finite element method (FEM) to establish a two-dimensional symmetric model of a disc-type suspension insulator under different icing conditions, and performs simulation calculation through COMSOL software. The insulator structure size, electrical boundary conditions, and icing medium characteristics are considered in the modeling process, while the influences of the conductor, water droplets, airflow, corona discharge, local arc, and leakage current are ignored. However, this model does not consider that the insulator unit near the power conductor end bears higher voltage due to the influence of parasitic capacitance, resulting in excessive electric field strength and leading to degradation of insulating performance.

[0044] Further, in step S1, the electric field distribution of the insulator string is simulated and calculated to obtain the voltage and electric field distribution of the insulator string when the grading ring is not installed. A three-dimensional simulation model is established using finite element simulation analysis software, including: according to the voltage grade of the transmission line, the actual working environment and requirements of the insulator string are analyzed and defined, and the specific structure parameters of the multi-stage grading ring are preliminarily set based on the line voltage grade, operating conditions, and safety requirements. The structure parameters include the number of grading rings, the diameter size of the ring body, the preliminary value of the cross-sectional area of the ring body, and the axial suspension height range of each grading ring relative to the insulator body. For example, for a typical 500 kV high-voltage transmission line, 3 to 5 grading rings are preliminarily selected, the ring body diameter of each grading ring is preliminarily set in the range of 300 mm to 1000 mm, the cross-sectional area is determined according to the electrical conductivity and electrical mechanical strength requirements of the conductive alloy material, and a solid conductor structure with a diameter of 20 mm to 40 mm is generally used. The height position of the ring body is determined by considering the actual installation length of the insulator string, the number of insulator units, the height of a single insulator, and the overall height of the insulator string, and the height range of the axial position of the grading ring relative to the insulator string is preliminarily determined.

[0045] After the preliminary determination of the structural parameters is completed, a three-dimensional simulation model is established using finite element simulation analysis software. First, typical structural components such as power transmission conductors, insulator strings, towers, and ground are constructed in the simulation software, and the material properties, electrical parameters, and geometric dimensions of each unit in the insulator string are clearly marked to ensure that the model accurately reflects the actual line operating state. Subsequently, the corresponding boundary conditions are input into the simulation model, including the line voltage level, the actual operating current of the power transmission conductor, the grounding condition, the surrounding environmental capacitance parameters, and the setting of the solution domain boundary and boundary conditions. After the simulation solution starts, the software calculates the potential, voltage distribution, electric field strength, and electric potential gradient of the entire insulator string and each unit insulator under the condition of not installing any grading ring. Through simulation calculation, the voltage distribution differences at various positions in the insulator string can be identified.

[0046] Further, in step S2, an electric field simulation analysis is performed, and the diameters, heights, and relative positions of the grading rings at each level are iteratively adjusted, including: based on the above-mentioned three-dimensional simulation model, the rated voltage of the actual power transmission line is applied to the conductor, and the electrical boundary conditions of the ground and tower are determined, and then the voltage and electric field distribution of the simulation model is calculated by the finite element analysis software to obtain detailed parameter information including the electric field strength, potential distribution, voltage gradient, etc. of the grading rings and the interior and surface of the insulator string.

[0047] The specific electric field parameters obtained through simulation analysis are used as input information, and the voltage borne by each insulator unit, the voltage gradient between each disc, and the electric field strength distribution diagram are obtained through analysis simulation. According to the simulation results, the areas of uneven voltage distribution in the insulator string are identified, and the parameter iterative optimization phase is entered, including the following specific steps:

[0048] Step Z1, set the objective function, and use the minimum voltage distribution coefficient deviation as the optimization target f 目标 : where U i is the voltage borne by the i-th insulator, U 额定 is the average voltage, is the distribution coefficient of the expected voltage, and n is the number of insulators.

[0049] Step Z2, after the identification of the uneven voltage area and the setting of the optimization function are completed, the parameter selection and adjustment phase is entered, and the selected parameters include: the diameters, cross-sectional areas, installation heights of the grading rings at each level, and the relative positions between the grading rings and the insulator bodies; the axial suspension height position of the grading ring also needs to be adjusted, which affects the coupling degree of the grading ring and the insulator disc body, and thus changes the regulation range of the local electric field.

[0050] Step Z3, input the above parameters as controllable variables into the finite element simulation platform, perform finite element simulation, and record the voltage distribution coefficient of each disc-shaped insulator, the electric field intensity nephogram, and the influence range of each stage of grading ring on electric field control.

[0051] Step Z4, analyze the simulation output. If the voltage distribution area is uniform and the voltage distribution coefficient error of each disc is less than ±10%, the current parameters are determined as "preliminary convergence"; otherwise, adjust the parameters according to the deviation direction of the voltage distribution, so that the voltage distribution coefficient error of each disc is less than ±10%.

[0052] Step Z5, output the final optimized parameter results, simulation atlas, and voltage distribution coefficient statistical table to form a complete design output document.

[0053] In the step Z2, the axial suspension height of the grading ring refers to the installation position in the longitudinal direction of the insulator string, which is defined by the vertical distance between the ring core and the uppermost end of the insulator string. The process of adjusting the axial suspension height of the grading ring is dynamically performed in combination with the feedback data of the finite element simulation. The electric field intensity nephogram and the voltage distribution coefficient are recalculated after each change in height until the voltage coefficient deviation of the spacer is less than ±10%.

[0054] In the step Z3, in the finite element simulation platform, a three-dimensional geometric model is constructed. After modeling, the finite element grid is divided, and the grid density is increased near the insulator surface, umbrella skirt edge, and grading ring. The boundary conditions are set: the conductor end is applied with a rated alternating voltage, the tower body and support are set as a ground boundary with a potential of 0, and the air area is set as a non-reflective electromagnetic boundary. After completing the boundary setting, the electrostatic field simulation module is started to solve. After the simulation is completed, the potential difference of each insulator is output, the corresponding voltage distribution coefficient is calculated, and the electric field intensity nephogram, voltage potential distribution graph, and axial potential curve graph are generated.

[0055] In the step Z4, the specific steps of adjusting the parameters according to the deviation direction of the voltage distribution are as follows: if the voltage distribution coefficient of the first or second insulator exceeds 10%-20% or more than the ideal uniform voltage distribution value in the simulation, it indicates that the first stage of grading ring has different electric field shielding effects on the conductor end. The diameter of the grading ring is adjusted from 800 mm to 1000 mm to expand its potential equivalent surface and enhance its suppression ability on the edge electric field lines. If the high voltage appears in the middle, a new stage of grading ring is added to extend the voltage distribution coverage range to the tower end. After each parameter adjustment, the simulation is verified to improve the voltage distribution, and the voltage distribution coefficient of each insulator is gradually averaged to achieve the goal of voltage difference within ±10% of each disc.

[0056] In this embodiment, refer to Figure 4Before the parameter iterative optimization, the first several insulators near the conductor end bear most of the voltage, and the voltage distribution coefficient of the first insulator is close to 0.18, while the voltage borne by the rear end is as low as 0.01 or even lower. Such uneven voltage distribution can cause the first end insulator to be in high electric stress for a long time, and is prone to local breakdown, corona discharge or aging failure. After the introduction of the multi-stage grading ring structure and the optimization through finite element simulation, each insulator bears almost equal voltage, and the voltage distribution coefficient is close to 0.05. Such distribution reduces the local electric field strength and enhances the overall stability and service life of the insulator.

[0057] In the embodiment, referring to Figure 5 , before the parameter iterative optimization, the first several insulators near the conductor end bear disproportionately high voltage, and the first insulator reaches 0.18, and then decreases. Such voltage concentration can cause the front end insulator to have an excessively strong electric field, increased risk of local breakdown and flashover. After the arrangement of the multi-stage grading ring and the structure iterative optimization through finite element simulation, the insulator voltage distribution tends to be balanced, and the voltage distribution coefficient of each piece is between 0.045 and 0.055 with slight fluctuations.

[0058] Further, the step S3 of fixing the grading ring at the axial position of the insulator string includes the following specific content: the optimized grading ring is made of aluminum alloy material with excellent electrical conductivity and strong corrosion resistance. The aluminum alloy material has high electrical conductivity and good mechanical strength, and can operate for a long time in high-voltage, atmospheric exposure, high-humidity and polluted environments without failure. The main body of the grading ring is in a ring structure, and the inner diameter is designed to be slightly larger than the maximum outer diameter of the insulator body. The ring body is provided with clamping components on both sides for fixation.

[0059] The position of the ring body is adjusted by using an adjustable suspension device of a multi-stage grading ring, as shown in Figure 6 , the adjustable suspension device includes an insulating adjusting rod and a ring-shaped clamping mechanism. One end of the adjusting rod is fixed on the insulator umbrella skirt structure, and the other end is connected to the ring-shaped clamping mechanism through a threaded interface. The installer can realize the up-down fine adjustment of the grading ring in the vertical direction by rotating the thread or replacing different hole positions, and the adjustment range can reach ±50mm to ±150mm, meeting the needs of on-site voltage distribution fine adjustment.

[0060] Further, the step S4 of adding nano-particles into the insulating material matrix comprises: selecting ceramic base material powder with high strength and high insulation performance, including alumina and magnesium oxide. Nano-particles with high dielectric constant are introduced in a proportion of 2% to 5%. Through the disturbance of the nano-particles to the electric field lines in the micro scale, a micro "electric potential buffer zone" can be formed in the overall material, effectively reducing the risk of local electric field concentration. In order to ensure the sufficient mixing of the ceramic powder and the nano-particles and achieve nano-scale dispersion, high-energy ball milling technology is used for mixing treatment. The high-energy ball milling technology homogenizes the powder with different particle sizes and properties in a short time through mechanical energy to form a uniform mixture. The ball milling time is controlled to be more than 12 hours. After the mixing is completed, the nano-composite ceramic powder is put into a high-precision metal mold for high-pressure pressing forming. The cold isostatic pressing is used in the pressing process, and the pressure is applied between 150 MPa and 300 MPa, so that the powder particles are densely packed in the mold cavity to preliminarily form a green body with structural strength. Next, the formed body is placed in a high-temperature sintering furnace for sintering and solidification treatment. The sintering process is carried out in an atmosphere-controlled manner, the temperature is set to be between 1250°C and 1450°C, and the heating rate is controlled to be 35°C / min to avoid micro-cracks or uneven sintering caused by rapid thermal expansion. The sintering holding time is 24 hours, during which the material undergoes solid phase reaction, grain rearrangement and densification process, and finally forms a composite ceramic body with excellent dielectric performance and structural integrity. Finally, in order to enhance the anti-fouling, moisture resistance and weather resistance of the insulator, a layer of high-performance silicone rubber coating is covered on the outer surface of the insulator body. The coating uses liquid silicone rubber material, which is applied by spraying, brushing or dipping, and is formed into a solid cover layer by room temperature or high temperature vulcanization. The thickness of the coating is controlled to be between 0.5 and 1.5 mm.

[0061] The present application realizes the balanced control of the voltage distribution of the insulator string through finite element simulation analysis and optimization design, effectively solves the phenomenon that the insulator near the conductor end bears higher voltage stress and is prone to local electric field overloading due to uneven voltage distribution of the disc-type suspension insulator string. The present application improves the insulation reliability and service life of the insulator by iteratively adjusting the parameters of the grading ring and combining the nano-particle reinforced insulating material performance. Specifically, the method uses finite element simulation software to accurately analyze the electric field distribution, optimizes the diameter, height and position of the grading ring, so that the voltage distribution coefficient of each insulator unit tends to be balanced, and the nano-particle is added to improve the anti-fouling, moisture resistance and weather resistance of the material.

[0062] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0063] Finally: the above only for the preferred embodiments of the present application, and not for limiting the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the scope of protection of the present application.

Claims

1. A method for voltage equalization control of a disc-type suspension insulator, characterized in that, The method comprises the following steps: Step S1, simulating and calculating the electric field distribution of the insulator string to obtain the voltage and electric field distribution of the insulator string without installing the grading ring, and establishing a three-dimensional simulation model by using finite element simulation analysis software; Step S2, performing electric field simulation analysis and iteratively adjusting the diameter, height and relative position of each grading ring; Step S3, fixing the grading ring at the axial position of the insulator string; Step S4, adding nano-sized particles to the insulating material matrix; In the step S2, the voltage and electric field distribution of the three-dimensional simulation model is calculated to obtain the electric field intensity, potential distribution and voltage gradient parameters inside and outside the grading ring and the insulator string; taking the above as input, the voltage and electric field distribution borne by each insulator unit is analyzed, the area with uneven voltage distribution is identified, and parameter iterative optimization is performed: Step Z1, minimizing the voltage distribution coefficient deviation as the objective function; Step Z2, taking the diameter, cross-sectional area, installation height of each grading ring and the relative position between the grading ring and the insulator body as parameters, and adjusting the axial suspension height position of the grading ring; Step Z3, inputting the above parameters into the finite element simulation platform for finite element simulation; Step Z4, analyzing the simulation output, if the voltage distribution area is uniform and the voltage distribution coefficient error of each disc is <±10%, the current parameters are judged as "preliminary convergence"; otherwise, the parameters are adjusted according to the deviation direction of the voltage distribution, so that the voltage distribution coefficient error of each disc is <±10%; Step Z5, outputting the final optimized parameter results, simulation atlas and voltage distribution coefficient statistical table.

2. A method for voltage equalization control of a disc-type suspension insulator according to claim 1, characterized in that In the step Z2, the axial suspension height of the grading ring refers to the installation position in the longitudinal direction of the insulator string, which is defined by the vertical distance between the ring core and the uppermost end of the insulator string. The process of adjusting the axial suspension height position of the grading ring is dynamically performed in combination with the feedback data of the finite element simulation. The electric field intensity cloud map and the voltage distribution coefficient are recalculated after changing the height each time until the spacer voltage coefficient deviation is less than ±10%.

3. The method of claim 1, wherein the voltage equalization control method of a disc-type suspension insulator is characterized by In the step Z3, in the finite element simulation platform, a three-dimensional geometric model is constructed, after modeling, the finite element grid is divided, and the grid density is increased near the insulator surface, umbrella skirt edge and grading ring; the boundary conditions are set: the conductor end is applied with rated alternating voltage, the tower body and support are set as the ground boundary with potential of 0, and the air area is set as the non-reflective electromagnetic boundary; after completing the boundary setting, the electrostatic field simulation module is started to solve; After the simulation is completed, the potential difference of each insulator is output, the corresponding voltage distribution coefficient is calculated, and the electric field intensity cloud map, voltage potential distribution map and axial potential curve map are generated.

4. The method of claim 1, wherein the voltage equalization control method of a disc-shaped suspension insulator is characterized by, According to the deviation direction of the voltage distribution, the specific steps of adjusting the parameters are as follows: if the voltage distribution coefficient of the first or second insulator exceeds 10%-20% or more than the ideal uniform voltage distribution value in simulation, it is indicated that the first-stage grading ring has different electric field shielding effects on the conductor end, the diameter of the grading ring is adjusted from 800 mm to 1000 mm to expand the potential equivalent surface and enhance the suppression ability of the edge electric field lines; if the high voltage appears in the middle, a new first-stage grading ring is added to extend the voltage distribution coverage to the tower end; after each parameter adjustment, the simulation is re-verified to improve the voltage distribution, and the voltage distribution coefficient of each insulator is gradually averaged to achieve the target of ±10% voltage difference of each disc.

5. The method of claim 1, wherein the voltage equalization control method of a disc-shaped suspension insulator is characterized by, In the step S3, the optimized grading ring is made of aluminum alloy material, and the main body of the grading ring is in a ring structure, the inner diameter of which is greater than the maximum outer diameter of the insulator body, and clamping components for fixation are arranged on both sides of the ring body.

6. The method of claim 1, wherein the voltage equalization control method of a disc-shaped suspension insulator is characterized by, In the step S3, the adjustable suspension device including the multi-stage grading ring of the insulating adjusting rod and the ring-shaped clamping mechanism is used to adjust the position of the ring body, one end of the adjusting rod is fixed on the insulator umbrella skirt structure, and the other end is connected to the ring-shaped clamping mechanism through a threaded interface, and the adjusting range is ±50 mm to ±150 mm.

7. The method of claim 1, wherein the voltage equalization control method of a disc-shaped suspension insulator is characterized by, In the step S4, the ceramic base material powder of alumina and magnesium oxide is selected, and the nano-particles with high dielectric constant are introduced in a proportion of 2%-5%.

8. The method of claim 1, wherein the voltage equalization control method of a disc-shaped suspension insulator is characterized by, In the step S4, the high-energy ball milling technology is used to mix the ceramic powder and the nano-particles, and the ball milling time is controlled to be more than 12 hours to fully homogenize the powder.

9. The method of claim 1, wherein the voltage equalization control method of a disc-shaped suspension insulator is characterized by, In the step S4, the mixed nano-composite ceramic powder is pressed by cold isostatic pressing process, and the pressure applied is between 150 MPa and 300 MPa to form a green body.

Images