Optimization method for composite gradient interface insulation of insulator and related device

Abstract

The invention discloses an optimization method for composite gradient interface insulation of an insulator and a related device, which considers the potential source of surface charges of the insulator in a direct current electric field and the influence of a multi-field coupling environment, and establishes an electric-thermal-current multi-field coupling simulation model for surface charge accumulation of the direct current insulator. Different insulator surface coating schemes are provided by considering electric field distribution modes and surface charge accumulation characteristics of different types of insulator shapes. Finally, an insulator tangential and normal electric field regulation and control strategy combining the geometric structure and surface nonlinear coating partition gradient coating is formed. Therefore, the problems that a quantitative optimization method of the direct-current insulator is lacked at present, and the specific complex curved surface geometric structure of the basin-type insulator cannot be fully considered in the aspect of the surface coating technology are solved.

Description

Technical Field

[0001] The invention relates to the technical field of gas-insulated power transmission lines, and in particular to an optimization method for composite gradient interface insulation of an insulator and a related device. Background Art

[0002] High-voltage direct current transmission technology is an important physical support for the grid connection of new energy and the safe and stable operation of large power grids. Gas insulated transmission lines (GIL) have many advantages such as small size, high current capacity and wide application range, and have gradually become an important equipment support for energy transmission, and are increasingly valued by academia and industry.

[0003] Although GIL gas-insulated transmission equipment has been widely used, insulation failure is still the main cause of equipment failure, safety and economic losses, and it will be more complicated and severe under DC conditions. There are two main sources of failure: First, the accumulation of charge at the gas-solid interface leads to increased electrical stress on the insulator surface. Second, the harm of metal particles will be more prominent. The interaction of charge accumulation and metal particles will more easily lead to insulation failure and severe ablation failure at the insulator interface. Therefore, the insulation of the insulator interface has always been the weak link in the composite insulation system of DC pipeline transmission.

[0004] The existing design of DC pot-type insulators is often result-oriented, and there is a lack of quantitative optimization methods for DC insulators. At present, the design methods and theories of AC GIL / GIS insulators are relatively mature and can provide references for DC insulator design. However, the existing AC insulator design methods rely on the segmentation, parameterization and coordinate processing of geometric structures such as surface curvature, insulator thickness, and inclination. Due to the multivariate geometric constraints and the need to optimize a large number of parameters at the same time, the huge amount of calculation makes this method more limited and more suitable for the local optimization of the key structures of the insulator. The characterization method of the complex curved surface geometry of the insulator needs further study. Furthermore, the current research work has not fully considered the complex curved surface geometry unique to pot-type insulators in terms of surface coating technology, which limits its potential in electric field regulation. In addition, there is no generally recognized standard for the selection of conductivity parameters for insulator surface coatings. Too low conductivity parameters may not be able to effectively regulate the surface charge distribution and electric field strength, while too high conductivity may lead to significant energy loss. Therefore, in order to optimize the performance of gradient coatings, it is necessary to conduct more detailed research and selection of coating parameters. Summary of the invention

[0005] The present invention provides an optimization method and related device for composite gradient interface insulation of an insulator, which are used to solve the problem that there is currently a lack of quantitative optimization methods for DC insulators and that the complex curved surface geometric structure unique to pot-type insulators has not been fully considered in surface coating technology.

[0006] In view of this, the first aspect of the present application provides a method for optimizing composite gradient interface insulation of an insulator, the method comprising:

[0007] Construct an electric-thermal-fluid multi-field coupling simulation model for charge accumulation on the insulator surface to be optimized;

[0008] Establishing geometric models of insulators of several geometric shapes, and analyzing and comparing the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with the electric-thermal-fluid multi-field coupling simulation model, to determine the insulator with the optimal geometric shape;

[0009] According to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator of the optimal geometric shape, the surface of the insulator of the optimal geometric shape is divided into a plurality of analysis areas;

[0010] Several coating schemes are respectively set in each of the analysis areas, and the optimal coating scheme is determined by comparing the regulating effect of each coating scheme on the local surface electric field and surface charge distribution in each of the analysis areas.

[0011] Optionally, the establishing of geometric models of insulators of several geometric shapes, and analyzing and comparing the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with the electric-thermal-fluid multi-field coupling simulation model to determine the insulator of the optimal geometric shape, includes:

[0012] Construct the geometric models of disc insulator, large-taper pot insulator and small-taper pot insulator respectively;

[0013] Based on each of the geometric models and in combination with the electric-thermal-fluid multi-field coupling simulation model, the normal field intensity distribution, tangential field intensity distribution and surface charge distribution of the disc insulator, the large-taper pot insulator and the small-taper pot insulator are analyzed and compared to obtain an insulator with an optimal geometric shape, and the insulator with the optimal geometric shape is the small-taper pot insulator.

[0014] Optionally, the surface of the insulator with the optimal geometric shape is divided into a plurality of analysis areas according to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator with the optimal geometric shape, including:

[0015] According to the normal field intensity distribution and the surface tangential field intensity distribution of the small-taper pot-type insulator, the convex side surface and the concave side surface of the small-taper pot-type insulator are respectively divided into a plurality of analysis areas.

[0016] Optionally, several coating schemes are respectively set in each of the analysis areas, and the optimal coating scheme is determined by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each of the analysis areas, including:

[0017] Several coating schemes are respectively set in each of the analysis areas, wherein the several coating schemes include: several nonlinear conductive coatings with different parameters, and nanocomposite coatings;

[0018] Determine the optimal coating scheme by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each analysis area;

[0019] The regulation effect is calculated by a quantitative formula of the average gradient of the tangential field strength on the surface of the insulator, and the quantitative formula is:

[0020] ;

[0021] In the formula, is the average gradient of the tangential field strength on the insulator surface; is the tangential electric field strength along the surface of the insulator; is the average working field strength on the surface of the basin insulator; It is the distance along the surface of the convex or concave side of the insulator.

[0022] A second aspect of the present application provides an optimization system for composite gradient interface insulation of an insulator, the system comprising:

[0023] A construction unit, used to construct an electric-thermal-fluid multi-field coupling simulation model of charge accumulation on the surface of the insulator to be optimized;

[0024] A comparison unit is used to establish geometric models of insulators of several geometric shapes, and analyze and compare the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with the electric-thermal-fluid multi-field coupling simulation model to determine the insulator with the optimal geometric shape;

[0025] A division unit, used for dividing the surface of the insulator of the optimal geometric shape into a plurality of analysis areas according to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator of the optimal geometric shape;

[0026] The analysis unit is used to set several coating schemes in each of the analysis areas, and determine the optimal coating scheme by comparing the regulating effect of each of the coating schemes on the local surface electric field and surface charge distribution in each of the analysis areas.

[0027] Optionally, the comparison unit is specifically used to:

[0028] Construct the geometric models of disc insulator, large-taper pot insulator and small-taper pot insulator respectively;

[0029] Based on each of the geometric models and in combination with the electric-thermal-fluid multi-field coupling simulation model, the normal field intensity distribution, tangential field intensity distribution and surface charge distribution of the disc insulator, the large-taper pot insulator and the small-taper pot insulator are analyzed and compared to obtain an insulator with an optimal geometric shape, and the insulator with the optimal geometric shape is the small-taper pot insulator.

[0030] Optionally, the division unit is specifically used to:

[0031] According to the normal field intensity distribution and the surface tangential field intensity distribution of the small-taper pot-type insulator, the convex side surface and the concave side surface of the small-taper pot-type insulator are respectively divided into a plurality of analysis areas.

[0032] Optionally, the analysis unit is specifically used to:

[0033] Several coating schemes are respectively set in each of the analysis areas, wherein the several coating schemes include: several nonlinear conductive coatings with different parameters, and nanocomposite coatings;

[0034] Determine the optimal coating scheme by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each analysis area;

[0035] The regulation effect is calculated by a quantitative formula of the average gradient of the tangential field strength on the surface of the insulator, and the quantitative formula is:

[0036] ;

[0037] In the formula, is the average gradient of the tangential field strength on the insulator surface; is the tangential electric field strength along the surface of the insulator; is the average working field strength on the surface of the basin insulator; It is the distance along the surface of the convex or concave side of the insulator.

[0038] A third aspect of the present invention provides an optimization device for composite gradient interface insulation of an insulator, the device comprising a processor and a memory:

[0039] The memory is used to store program code and transmit the program code to the processor;

[0040] The processor is used to execute the steps of the method for optimizing composite gradient interface insulation of insulators as described in the first aspect according to the instructions in the program code.

[0041] A fourth aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for optimizing composite gradient interface insulation of insulators described in the first aspect.

[0042] It can be seen from the above technical solutions that the present invention has the following advantages:

[0043] The present invention significantly improves the electrical performance of the DC composite gradient insulation system by optimizing the geometric structure of the insulator and applying a nonlinear conductive coating.

[0044] First, the present invention effectively reduces the maximum and average values ​​of the normal field strength and reduces the accumulation of surface charges by designing a small-taper basin insulator. This design not only improves the insulation performance of the insulator, but also reduces the electric field distortion caused by charge accumulation, thereby enhancing the reliability and stability of the insulator. In addition, through simulation analysis and experimental verification, it is proved that the optimized insulator structure can effectively control the electric field distribution in practical applications, reduce the risk of local excessive electric field, and extend the service life of the equipment. Secondly, the nonlinear conductive coating technology introduced by the present invention realizes the fine regulation of the tangential field strength by coating in different regions on the surface of the insulator. The application of the coating not only reduces the maximum value of the local tangential field strength, but also promotes the dissipation of the accumulated charge, further enhancing the surface insulation performance of the insulator. This partitioned gradient coating strategy combines the conductivity parameters of the coating material and the electric field distribution characteristics of the insulator surface, realizes the uniform distribution of the tangential field strength on the insulator surface, effectively avoids the over-regulation phenomenon, and improves the overall performance of the insulator. By quantitatively evaluating the average gradient of the tangential field strength, the present invention provides a new theoretical basis and practical guidance for the design of DC insulators, which is helpful to promote the development of high-voltage DC transmission technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1A schematic flow chart of a method for optimizing composite gradient interface insulation of an insulator provided in an embodiment of the present invention;

[0047] Figure 2a An insulator model of a disc insulator geometric structure provided by an embodiment of the present invention;

[0048] Figure 2b An insulator model of a large-taper pot-type insulator geometric structure provided by an embodiment of the present invention;

[0049] Figure 2c An insulator model of a small-taper pot-type insulator geometric structure provided by an embodiment of the present invention;

[0050] Figure 3a The normal electric field of the disc insulator provided by the embodiment of the present invention;

[0051] Figure 3b The tangential electric field of the disc insulator provided by the embodiment of the present invention;

[0052] Figure 4a The normal electric field of the large-taper insulator provided by the embodiment of the present invention;

[0053] Figure 4b The tangential electric field of the large-taper insulator provided by the embodiment of the present invention;

[0054] Figure 5a The normal electric field of the small-taper insulator provided by the embodiment of the present invention;

[0055] Figure 5b The tangential electric field of the small-taper insulator provided by the embodiment of the present invention;

[0056] Figure 6 A schematic diagram showing that the surface of a small-taper pot-type insulator provided in an embodiment of the present invention is divided into three major regions;

[0057] Figure 7a The surface tangential field intensity distribution of the coating in the convex side region 1 of the small-taper pot-type insulator provided in an embodiment of the present invention;

[0058] Figure 7b The surface tangential field intensity distribution of the coating in the concave area 1 of the small-taper pot-type insulator provided in an embodiment of the present invention;

[0059] Figure 8 The surface charge distribution of coating in area 1 of the convex side of a small-taper pot-type insulator provided in an embodiment of the present invention (from left to right in the figure, they are S1 coating, S2 coating, and S3 coating);

[0060] Fig. 9The surface charge distribution of coating in concave area 1 of a small-taper pot-type insulator provided in an embodiment of the present invention (from left to right in the figure, they are S1 coating, S2 coating, and S3 coating);

[0061] Fig.10a The surface tangential field intensity distribution of the coating in the convex side region 2 of the small-taper pot-type insulator provided in an embodiment of the present invention;

[0062] Fig.10b The surface tangential field intensity distribution of the coating in the concave side region 2 of the small-taper pot-type insulator provided in an embodiment of the present invention;

[0063] Fig.11 The surface charge distribution of coating in area 2 of the convex side of a small-taper pot-type insulator provided in an embodiment of the present invention (from left to right in the figure, they are S1 coating, S2 coating, and S3 coating);

[0064] Fig.12 The surface charge distribution of coating in concave area 2 of a small-taper pot-type insulator provided in an embodiment of the present invention (from left to right in the figure, they are S1 coating, S2 coating, and S3 coating);

[0065] Fig.13a The surface tangential field intensity distribution of the coating in the convex side region 3 of the small-taper pot-type insulator provided in an embodiment of the present invention;

[0066] Fig.13b The surface tangential field intensity distribution of the coating in the concave area 3 of the small-taper pot-type insulator provided in an embodiment of the present invention;

[0067] Fig.14 The surface charge distribution of coatings in the convex side region 3 of a small-taper pot-type insulator provided in an embodiment of the present invention (from left to right in the figure, they are S1 coating, S2 coating, and S3 coating);

[0068] Fig.15 The surface charge distribution of coatings in the concave area 3 of a small-taper pot-type insulator provided in an embodiment of the present invention (from left to right in the figure, they are S1 coating, S2 coating, and S3 coating);

[0069] Fig.16 A schematic structural diagram of an optimization system for composite gradient interface insulation of insulators provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] See also Figure 1 , an optimization method for composite gradient interface insulation of an insulator provided in an embodiment of the present invention comprises:

[0072] Step 101: construct an electric-thermal-fluid multi-field coupling simulation model for charge accumulation on the surface of an insulator to be optimized.

[0073] It should be noted that, considering the potential sources of surface charge on insulators in DC electric fields and the influence of multi-field coupling environment, the present application first establishes an electric-thermal-fluid multi-field coupling simulation model (multi-physics field coupling simulation model) of surface charge accumulation on insulators to be optimized, wherein the insulator to be optimized in the present application is a DC insulator; specifically, those skilled in the art can use existing simulation software such as COMSOL to construct a multi-physics field coupling simulation model, an electric-thermal-fluid multi-field coupling simulation model of surface charge accumulation on insulators to be optimized.

[0074] Step 102: Establish geometric models of insulators of several geometric shapes, and analyze and compare the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with the electric-thermal-fluid multi-field coupling simulation model to determine the insulator with the optimal geometric shape.

[0075] In one embodiment, step 102 specifically includes:

[0076] The geometric models of disc insulators, large-taper pot insulators and small-taper pot insulators are constructed respectively. Based on each geometric model and combined with the electric-thermal-fluid multi-field coupling simulation model, the normal field intensity distribution, tangential field intensity distribution and surface charge distribution of disc insulators, large-taper pot insulators and small-taper pot insulators are analyzed and compared to obtain the insulator with the optimal geometric shape, which is the small-taper pot insulator.

[0077] It should be noted that the distribution of the tangential and normal electric field strength along the surface of the insulator under the DC electric field is closely related to the geometric structure of the insulator. Drawing on the design experience of AC and DC insulators, this application has established the following design methods based on the existing disc insulators, large-taper basin insulators and small-taper basin insulators: Figure 2a , Figure 2b , Figure 2cThe three typical insulator geometric models (disc insulator, large-taper pot insulator, small-taper pot insulator) are shown. The DC pipeline model has a central conductor with an outer diameter of 180 mm and a wall thickness of 13 mm, a ground electrode with an inner diameter of 500 mm and a wall thickness of 5 mm; the GIL pipeline cavity is filled with SF6 insulating gas at a pressure of 0.1 MPa.

[0078] When conducting the simulation analysis, a voltage of +500 kV is applied to the central conductor and maintained for 10 hours. Relying on the established insulator geometric model and the electric-thermal-fluid multi-field coupling simulation model of charge accumulation on the insulator surface in step 101, the surface charge density and distribution characteristics of the electric field intensity along the surface of the insulator are studied.

[0079] Specifically, the normal electric field intensity, tangential electric field intensity and surface charge distribution of disc insulators, large-taper basin insulators and small-taper basin insulators are compared and analyzed. The normal and tangential electric field distributions of the insulator surfaces of the three structures are shown in Figure 2. Figure 3a , Figure 3b , Figure 4a , Figure 4b , Figure 5a , Figure 5b It can be found that the optimized geometric structure has an obvious control effect on the normal field intensity on the insulator surface.

[0080] The normal field intensity distribution shows a "three-peak" distribution feature. The use of small-taper basin insulators can effectively reduce the height of each peak, thereby reducing the maximum value of the normal field intensity E n max The average normal field strength E n mean At the same time, since the surface normal field strength of the insulator directly determines the surface charge distribution, the surface charge accumulation of the small-tapered basin insulator is smaller, the degree of electric field distortion caused by the transient process is also lighter, and the difference between the initial state and the transient normal field strength is also smaller. n The insulator body passes through the gas-solid interface and finally enters the gas side. The focus of geometric structure optimization is to reduce the charge accumulation formed by current conduction on the insulator body side by reducing the normal electric field strength inside the insulator body, thereby reducing the maximum value and average normal field strength of the normal field strength component on the gas side insulator surface, and realizing the regulation of the surface normal field strength.

[0081] Step 103: According to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator with the optimal geometric shape, the surface of the insulator with the optimal geometric shape is divided into a plurality of analysis areas.

[0082] In one embodiment, step 103 specifically includes:

[0083] According to the normal field intensity distribution and the tangential field intensity distribution along the surface of the small-taper pot-type insulator, the convex side and concave side of the small-taper pot-type insulator are divided into several analysis areas respectively.

[0084] It should be noted that according to the tangential and normal electric field distribution characteristics of small-taper pot insulators, taking the convex side of the insulator as an example, the surface of the pot insulator is divided into the following Figure 6 The three major regions are shown: the surface near the center conductor is region 1, the middle of the insulator is region 2, and the surface near the ground electrode is region 3. Since the electric field and charge distribution on the convex and concave sides of the small-taper pot insulator have similar characteristics, the concave side surface is also divided into three regions in the same way.

[0085] Step 104 , setting a plurality of coating schemes in each analysis area, and determining the optimal coating scheme by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each analysis area.

[0086] In one embodiment, step 104 specifically includes:

[0087] Several coating schemes are respectively set in each analysis area, wherein the several coating schemes include: several nonlinear conductivity coatings with different parameters;

[0088] By comparing the regulation effect of various coating schemes on the local surface electric field and surface charge distribution in each analysis area, the optimal coating scheme is determined;

[0089] Among them, the regulation effect is calculated by the quantitative formula of the average gradient of the tangential field strength on the insulator surface, and the quantitative formula is:

[0090] ;

[0091] In the formula, is the average gradient of the tangential field strength on the insulator surface; is the tangential electric field strength along the surface of the insulator; is the average working field strength on the surface of the basin insulator; It is the distance along the surface of the convex or concave side of the insulator.

[0092] It should be noted that the present application sets up nonlinear conductive coatings in three areas respectively, combines charge accumulation multi-field coupling simulation, and compares the regulating effect of each area coating scheme on the local surface electric field and surface charge distribution, so as to obtain the optimal insulator surface coating mode and coating parameters.

[0093] For region 1, when using nonlinear conductive coatings with different parameters, the tangential field intensity distribution on the convex and concave sides of the insulator is as follows: Figure 7a and 7b As shown, the surface charge distribution on both sides of the convex and concave surfaces is as follows: Figure 8 and Fig. 9 When there is no coating, the maximum tangential field strength on both sides of the convex and concave appears at the three-junction point and decreases evenly along the insulating surface; after the coating is introduced, the E t The maximum values ​​are all reduced. The S1 coating and the S2 coating show a surge in the tangential field intensity at the boundary between region 1 and region 2. However, when the S1 coating is used, the maximum tangential field intensity is close to the maximum value without coating. This is because the introduction of the coating changes the charge distribution in region 1, resulting in opposite charge polarity or a sudden change in charge density at the boundary between the two regions, which is not conducive to surface insulation. The S3 coating and the S4 coating not only have similar control effects on the tangential field intensity but also have similar improvements on the charge distribution. The control effect on the tangential field intensity at the triple junction is weaker than that of the S1 and S2 coatings.

[0094] From the perspective of the regulation effect of the tangential field strength, the three coatings S1, S2, and S3 have good application potential; from the perspective of promoting charge dissipation, the S1 coating has a more obvious effect, and no opposite polarity charge appears at the coating boundary. Compared with the charge on the concave side of the small-taper insulator without surface coating, the maximum negative charge density of the center conductor is reduced from -42μC / m2 to -19μC / m2. Based on the analysis of Et and surface charge regulation effects, materials with similar parameters to the S1 coating can be selected as the coating for the convex and concave areas 1.

[0095] After the coating is introduced into area 2, the tangential field strength E of the insulator along the surface will be t Changes such as Fig.10a , 10b As shown in Figure 2, the tangential field strength in region 1 will decrease, while the tangential field strength in region 3 will increase. The effects of S2 coating and S3 coating are still similar. At the same time, the surface charge distribution on the convex and concave sides of the insulator is given, as shown in Figure 2. Fig.11 and Fig.12 As shown. For the convex side of the insulator, the S1 coating and the S2 coating significantly raised the tangential electric field strength of region 2, even higher than the maximum value without coating, so these two parameter coatings are not suitable for coating the convex side of the insulator; the S2 coating and the S3 coating not only reduce the maximum value of the tangential field strength but also reduce the charge density of region 2, and are suitable for coating region 2 on the convex side. For the concave side, when the S1 coating is used, the surface charge density of region 2 approaches 0, and the overall tangential field strength of the concave side is more uniform, without abnormal surges, and is suitable for coating region 2 on the concave side.

[0096] For region 3, the use of nonlinear conductive coating with parameter S1 will increase the tangential field strength at the junction of the three electrodes on both sides of the convex and concave sides abnormally, and exceed the tangential field strength E in this region when there is no coating. t The maximum value is Fig.13a , Fig.13bAs shown in the figure, this is contrary to the control goal of reducing the tangential field strength. When other parameter coatings are used, the tangential field strength is optimized to varying degrees, and the maximum value decreases while the overall becomes more uniform. The charge distribution on the convex and concave sides of the insulator is shown in the figure below. Fig.14 and Fig.15 As shown, the charge regulation effect shows that when S3 coating is used, the charge density in region 3 is the smallest and is significantly improved without coating.

[0097] In terms of insulator surface coating and tangential field intensity control, a comparative analysis of the insulator surface area coating schemes shows that the introduction of nonlinear conductive coating can further reduce the local tangential field intensity E in the coating area. t The maximum value makes the tangential field strength in the corresponding area more uniform as a whole and promotes the dissipation of accumulated charges.

[0098] However, it is worth noting that when using the zone coating method, there will be a large difference in charge density at the boundaries of each zone, which may lead to a local surge in the tangential field strength and over-regulation. At this time, directly comparing the tangential field strength optimization effect cannot show the advantages of the surface coating.

[0099] Therefore, according to the surface contour structure and electric field distribution characteristics of the insulator, it is of great significance to select coating materials with appropriate conductivity parameters for the three regions and reduce the differences in dielectric parameters between regional coatings to improve the tangential field strength distribution on the insulator surface.

[0100] In order to characterize the effect of nonlinear conductive coating on the tangential field intensity control of the insulator surface, this embodiment defines the average tangential field intensity gradient f on the insulator surface as t , to quantitatively evaluate the tangential field strength E t Distribution characteristics:

[0101] (1)

[0102] Where: E t E is the tangential electric field strength along the insulator surface; mean is the average working field strength on the surface of the basin insulator, that is, the ratio of the working voltage to the insulation distance along the insulator surface; l is the distance along the convex or concave side of the insulator surface. The average gradient of the tangential field strength on the insulator surface f t The smaller the value, the more uniform the distribution of the tangential field strength component along the radial direction of the insulator, and the closer the value along the surface is to the average working field strength on the surface, the more fully the insulation distance along the surface of the insulator is utilized, and it is less likely that the tangential field strength is locally too high. Therefore, the average gradient of the surface tangential field strength f should be controlled in the design of DC insulators. t At a lower level.

[0103] In summary, the normal field strength E on the insulator surface can be controlled by combining the optimization of the insulator geometry with the zoned gradient coating of the surface nonlinear conductivity coating. n With the tangential field strength E t , thereby constructing a DC composite gradient insulation system to achieve enhanced interface electrical properties.

[0104] Furthermore, in one embodiment, the coating further comprises: a nanocomposite coating.

[0105] It should be noted that the present invention also provides an effective solution for improving the surface flashover performance of insulators: using nanocomposite coating technology. This solution involves coating a layer of composite material composed of nanoscale fillers and polymer matrix on the surface of the insulator. Nanofillers such as nano-silicon dioxide, carbon nanotubes or graphene can significantly improve the insulation performance and weather resistance of the coating due to their unique physical and chemical properties, such as high dielectric constant, high conductivity and excellent mechanical properties. By precisely controlling the dispersion of the nanofillers and the curing process of the coating, it can be ensured that the coating forms good adhesion with the surface of the insulator, while maintaining the uniformity and density of the coating, thereby effectively reducing the surface electric field strength and inhibiting local discharge. In addition, the nanocomposite coating also has self-repairing ability, which can repair minor defects caused by environmental erosion or mechanical damage and extend the service life of the insulator. The performance of the coating is verified through laboratory tests and field tests to ensure that it can provide stable insulation protection under different environmental conditions, thereby significantly improving the surface flashover performance of the insulator.

[0106] The present invention provides an optimization method for composite gradient interface insulation of insulators. Considering the potential sources of surface charges on insulators in DC electric fields and the influence of multi-field coupling environment, an electric-thermal-fluid multi-field coupling simulation model of surface charge accumulation on DC insulators is established. Considering the electric field distribution patterns and surface charge accumulation characteristics of different types of insulator shapes, different insulator surface coating schemes are proposed. Finally, a control strategy for the tangential and normal electric fields of insulators combining geometric structure and surface nonlinear coating zone gradient coating is formed. This solves the problem of the current lack of quantitative optimization methods for DC insulators and the problem that the complex curved surface geometric structure unique to pot-type insulators has not been fully considered in surface coating technology.

[0107] The above is an optimization method for composite gradient interface insulation of an insulator provided in an embodiment of the present invention, and the following is an optimization system for composite gradient interface insulation of an insulator provided in an embodiment of the present invention.

[0108] See also Fig.16 , an optimization system for composite gradient interface insulation of an insulator provided in an embodiment of the present invention comprises:

[0109] A construction unit 201 is used to construct an electric-thermal-fluid multi-field coupling simulation model of charge accumulation on the surface of the insulator to be optimized;

[0110] A comparison unit 202 is used to establish geometric models of insulators of various geometric shapes, and analyze and compare the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with an electric-thermal-fluid multi-field coupling simulation model to determine the insulator with the optimal geometric shape;

[0111] A division unit 203 is used to divide the surface of the insulator with the optimal geometric shape into a plurality of analysis areas according to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator with the optimal geometric shape;

[0112] The analysis unit 204 is used to set several coating schemes in each analysis area, and determine the optimal coating scheme by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each analysis area.

[0113] Furthermore, an embodiment of the present invention also provides an optimization device for composite gradient interface insulation of an insulator, the device comprising a processor and a memory:

[0114] The memory is used to store program code and transmit the program code to the processor;

[0115] The processor is used to execute the steps of the method for optimizing composite gradient interface insulation of insulators as described in the above method embodiment according to the instructions in the program code.

[0116] Furthermore, a computer-readable storage medium is provided in an embodiment of the present invention, and the computer-readable storage medium is used to store program codes, and the program codes are used to execute the optimization method of composite gradient interface insulation of insulators described in the above method embodiment.

[0117] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0118] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0119] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0120] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0121] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0122] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing composite gradient interface insulation of an insulator, characterized in that: include: Construct an electric-thermal-fluid multi-field coupling simulation model for charge accumulation on the insulator surface to be optimized; Establishing geometric models of insulators of several geometric shapes, and analyzing and comparing the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with the electric-thermal-fluid multi-field coupling simulation model, to determine the insulator with the optimal geometric shape; According to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator of the optimal geometric shape, the surface of the insulator of the optimal geometric shape is divided into a plurality of analysis areas; Several coating schemes are respectively set in each of the analysis areas, and the optimal coating scheme is determined by comparing the regulating effect of each coating scheme on the local surface electric field and surface charge distribution in each of the analysis areas.

2. The optimization method for composite gradient interface insulation of insulators according to claim 1, characterized in that: The geometric models of insulators with several geometric shapes are established, and the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators with various geometric shapes are analyzed and compared in combination with the electric-thermal-fluid multi-field coupling simulation model to determine the insulator with the optimal geometric shape, including: Construct the geometric models of disc insulator, large-taper pot insulator and small-taper pot insulator respectively; Based on each of the geometric models and in combination with the electric-thermal-fluid multi-field coupling simulation model, the normal field intensity distribution, tangential field intensity distribution and surface charge distribution of the disc insulator, the large-taper pot insulator and the small-taper pot insulator are analyzed and compared to obtain an insulator with an optimal geometric shape, and the insulator with the optimal geometric shape is the small-taper pot insulator.

3. The method for optimizing composite gradient interface insulation of insulators according to claim 2, characterized in that: According to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator of the optimal geometric shape, the surface of the insulator of the optimal geometric shape is divided into a plurality of analysis areas, including: According to the normal field intensity distribution and the surface tangential field intensity distribution of the small-taper pot-type insulator, the convex side surface and the concave side surface of the small-taper pot-type insulator are respectively divided into a plurality of analysis areas.

4. The method for optimizing composite gradient interface insulation of insulators according to claim 1 or 3, characterized in that: The method of setting up several coating schemes in each of the analysis areas, and determining the optimal coating scheme by comparing the regulation effect of each of the coating schemes on the local surface electric field and surface charge distribution in each of the analysis areas, comprises: Several coating schemes are respectively set in each of the analysis areas, wherein the several coating schemes include: several nonlinear conductive coatings with different parameters, and nanocomposite coatings; Determine the optimal coating scheme by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each analysis area; The regulation effect is calculated by a quantitative formula of the average gradient of the tangential field strength on the surface of the insulator, and the quantitative formula is: ； In the formula, is the average gradient of the tangential field strength on the insulator surface; is the tangential electric field strength along the surface of the insulator; is the average working field strength on the surface of the basin insulator; It is the distance along the surface of the convex or concave side of the insulator.

5. An optimization system for composite gradient interface insulation of insulators, characterized in that: include: A construction unit, used to construct an electric-thermal-fluid multi-field coupling simulation model of charge accumulation on the surface of the insulator to be optimized; A comparison unit is used to establish geometric models of insulators of several geometric shapes, and analyze and compare the surface charge density and distribution characteristics of the electric field intensity along the surface of insulators of various geometric shapes in combination with the electric-thermal-fluid multi-field coupling simulation model to determine the insulator with the optimal geometric shape; A division unit, used for dividing the surface of the insulator of the optimal geometric shape into a plurality of analysis areas according to the normal field intensity distribution and the tangential field intensity distribution along the surface of the insulator of the optimal geometric shape; The analysis unit is used to set several coating schemes in each of the analysis areas, and determine the optimal coating scheme by comparing the regulating effect of each of the coating schemes on the local surface electric field and surface charge distribution in each of the analysis areas.

6. The optimization system for composite gradient interface insulation of insulators according to claim 5, characterized in that: The comparison unit is specifically used for: Construct the geometric models of disc insulator, large-taper pot insulator and small-taper pot insulator respectively; Based on each of the geometric models and in combination with the electric-thermal-fluid multi-field coupling simulation model, the normal field intensity distribution, tangential field intensity distribution and surface charge distribution of the disc insulator, the large-taper pot insulator and the small-taper pot insulator are analyzed and compared to obtain an insulator with an optimal geometric shape, and the insulator with the optimal geometric shape is the small-taper pot insulator.

7. The optimization system for composite gradient interface insulation of insulators according to claim 6, characterized in that: The division unit is specifically used for: According to the normal field intensity distribution and the surface tangential field intensity distribution of the small-taper pot-type insulator, the convex side surface and the concave side surface of the small-taper pot-type insulator are respectively divided into a plurality of analysis areas.

8. The optimization system for composite gradient interface insulation of insulators according to claim 5 or 7, characterized in that: The analysis unit is specifically used for: Several coating schemes are respectively set in each of the analysis areas, wherein the several coating schemes include: several nonlinear conductive coatings with different parameters, and nanocomposite coatings; Determine the optimal coating scheme by comparing the regulation effect of each coating scheme on the local surface electric field and surface charge distribution in each analysis area; The regulation effect is calculated by a quantitative formula of the average gradient of the tangential field strength on the surface of the insulator, and the quantitative formula is: ； In the formula, is the average gradient of the tangential field strength on the insulator surface; is the tangential electric field strength along the surface of the insulator; is the average working field strength on the surface of the basin insulator; It is the distance along the surface of the convex or concave side of the insulator.

9. An optimization device for composite gradient interface insulation of insulators, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the optimization method of composite gradient interface insulation of insulators according to any one of claims 1 to 4 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for optimizing composite gradient interface insulation of insulators according to any one of claims 1 to 4.

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