Design method of coating for high-voltage transmission conductor

Abstract

The invention provides a design method of a coating for a high-voltage transmission conductor. The design method comprises the following steps: establishing an optical performance simulation calculation model of a'high-voltage transmission conductor-coating 'curved surface microstructure; coupling analysis is carried out, a high-voltage transmission conductor-coating microstructure parameter result set is obtained, and multi-target parameter optimization is carried out on the optical performance simulation calculation model; preparing a coating material according to an optimization result, and performing optical performance test verification on the material; and inputting a predicted value and an experimental value, correcting the optical simulation calculation model, and outputting an optimization scheme. According to the method, the advantages of the finite difference time domain method and the Monte Carlo method are combined, calculation is rapid and accurate, the adaptability to a special curved surface is high, the thickness of the designed coating is remarkably reduced, and therefore the heat dissipation and capacity increasing problems of the wire in the operation process are effectively solved.

Description

Technical Field

[0001] The invention belongs to the field of coating materials, and in particular relates to a design method for coatings used for high-voltage transmission lines. Background Art

[0002] Heat dissipation in high-voltage transmission lines has always been a key challenge in the power transmission sector. During operation, conductor temperatures rise significantly due to the combined effects of Joule heating generated by the current and solar radiation. For example, in high-temperature environments, conductor temperatures can reach over 80°C. This not only accelerates thermal aging but also increases conductor sag, making line maintenance more difficult and creating safety risks. Furthermore, elevated conductor temperatures reduce transmission capacity, impacting the operational efficiency of the power system.

[0003] To address this challenge, traditional heat dissipation solutions often employ thicker radiative cooling coatings to improve reflectivity and heat dissipation efficiency. However, these coatings are typically made of polymer materials, which have much lower thermal conductivity than metals. The multi-layer scattering effect of thick coatings also reduces visible-to-near-infrared reflectivity, ultimately reducing heat dissipation efficiency.

[0004] Existing technologies for heat dissipation coatings for high-voltage transmission lines still have the following problems: 1. A single heat dissipation mechanism fails to fully utilize the metallic reflective properties of the aluminum stranded conductor surface, relying solely on coating scattering. This results in insufficient thermal emissivity in the atmospheric window (8-13μm), limiting heat dissipation efficiency. 2. Poor surface adaptability. Traditional designs are based on planar models and fail to consider the distorting effect of the conductor's helical surface structure on the light scattering path, resulting in significant deviations in actual reflectivity.

[0005] Therefore, based on the limitations of the above-mentioned existing technologies, there is an urgent need for a photothermal coordinated control model based on the special surface characteristics of high-voltage transmission lines, which can design coatings that can be applied to high-voltage transmission lines more efficiently and at a low cost, thereby effectively solving the heat dissipation problems faced by high-voltage transmission lines during operation. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the object of the present invention is to provide a design method for a coating for a high-voltage transmission line, comprising the following steps:

[0007] S1. Establish a simulation model for the optical performance of the special curved surface microstructure of "high-voltage transmission line-coating", analyze the coupling effect of particle point scattering inside the synergistic coating and surface reflection of the aluminum stranded wire, and simulate the influence of different coating microstructures on light scattering, thermal emission and optical coupling effects;

[0008] S2. Utilize micro-nano fillers and microstructure design to increase shortwave scattering efficiency, inhibit shortwave absorption on metal surfaces, and reduce solar energy absorption; strengthen the optical resonance effect between functional fillers and metal substrates, enhancing thermal radiation capabilities in the atmospheric window band (8-13μm); simulate the optical interaction between microstructures and metal conductor substrates to ensure that the coating has stable optical properties on surfaces with different curvatures;

[0009] Based on the coupling analysis in step S1, a result set of microstructure parameters of the "high-voltage transmission line-coating" is obtained, and a multi-objective parameter optimization is performed on the optical performance simulation calculation model to optimize the microstructure parameters and coating thickness;

[0010] S3. preparing a coating material according to the optimization result of step S2, and performing an optical performance test to verify the material;

[0011] S4. Input the predicted value and experimental value, fuse the simulation and experimental data through the physical information neural network, correct the optical simulation calculation model and output the optimization solution.

[0012] In one embodiment, S1 specifically includes:

[0013] S11, geometrically modeling the "high-voltage transmission wire-coating" surface, inputting the wire spiral structure parameters and surface microstructure parameters, and establishing a high-precision surface model;

[0014] The surface compensation angle can be calculated according to the following formula:

[0015] Microstructure axial compensation angle

[0016] S12. Analysis of optical coupling effects on the curved surface of “high-voltage transmission line-coating”, calculation of equivalent interface parameters (equivalent scattering, absorption characteristics, etc.);

[0017] Input the parameters of the coating material particles and use the finite difference time domain method to calculate the equivalent scattering coefficient S eq , scattering efficiency η sca ,

[0018]

[0019] in, is the scattered power per unit solid angle, P in is the incident light power;

[0020] S13, counting the photon paths and calculating the total emissivity, absorptivity and emissivity of the coating;

[0021] Simulate the multiple reflection paths of the wire-coating surface microstructure, calculate the total reflectivity of the coating by counting photon paths through Monte Carlo ray tracing;

[0022] ρ tota l=ρ 颗粒 +ρ 导线 -ρ 颗粒 ·ρ 导线

[0023] Among them, ρ 颗粒 Reflectivity contributed by scattering of coating particles, ρ 导线 is the reflectivity of the metal surface of the high-voltage transmission line.

[0024] In one embodiment, the helical structure parameters of the wire include but are not limited to: radius of curvature, pitch; the surface microstructure parameters include but are not limited to: pit period, depth;

[0025] The parameters of the coating material particles include but are not limited to: particle size, volume concentration, and gradient distribution from the surface layer to the bottom layer.

[0026] In one embodiment, the multi-objective genetic algorithm is used to optimize the parameters in step S2.

[0027] The objective function is:

[0028] Maximize the solar band reflectivity ρ total ;

[0029] Maximize the atmospheric window thermal emissivity ε IR ;

[0030] Minimize coating thickness δ;

[0031] The constraints are: δ≤100μm, Λ / h≥1.2.

[0032] In one embodiment, S4 specifically includes:

[0033] S41, input incident light parameters, coating particle parameters, aluminum surface microstructure parameters, current density, and environmental parameters, and output reflectivity, absorptivity, conductor surface temperature, and heat flux density;

[0034] S42, embedding physical constraints;

[0035] S43, obtaining a loss function of the optical simulation calculation model;

[0036] The physical constraints include optical constraints;

[0037] The optical constraint condition is: ρ+α+τ=1;

[0038] Among them, ρ is the reflectivity, α is the absorptivity, and τ is the transmittance.

[0039] In one embodiment, the loss function is as follows:

[0040]

[0041] in, is the mean square error between the measured value and the predicted value, is the residual of the physical equation;

[0042]

[0043] A second aspect of the present application provides a coating for high-voltage transmission lines, which is prepared according to any of the above-mentioned design methods.

[0044] The present application also provides a high-voltage transmission wire comprising the coating.

[0045] The technical solution of this application aims to overcome the defects of the existing technology and proposes a design method for self-cooling and volume-increasing coatings for high-voltage transmission conductors based on the "point scattering-surface reflection coupling" mechanism. The microstructure of the ultra-thin radiative cooling coating material is designed by combining FDTD and Monte Carlo ray tracing methods. The single application of FDTD method is only applicable to micro-nanoscale particle scattering. When calculating the surface structure, the grid volume explodes, resulting in excessively high computational costs. The Monte Carlo ray tracing method alone is difficult to accurately describe the wave optical effects of subwavelength structures, such as resonance enhancement. The strategy of combining FDTD with Monte Carlo ray tracing methods in this application essentially solves the multi-scale photothermal coupling problem in the design of high-voltage transmission conductor coatings. At the microscopic level, FDTD is used to analyze the scattering / resonance effects of nanoparticles to improve the optical efficiency of single particles. At the macroscopic level, Monte Carlo quantifies the multiple reflection paths of the surface to correct engineering-level optical deviations. This application forms a "modeling-optimization-verification" closed loop through experimental verification, thereby enhancing technical reliability. This application establishes a geometric model of the wire's spiral surface, combining Monte Carlo ray tracing with FDTD simulation to quantify the impact of curvature on the light field distribution. This not only corrects the microstructure arrangement angle but also reduces reflectivity deviation. The optimized microstructure design method in this application achieves a material reflectivity of ≥90% in the solar band (0.3-2.5μm) and a thermal emissivity of ≥93% at the atmospheric window (8-13μm), achieving excellent radiative heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the design process of the present invention. DETAILED DESCRIPTION

[0047] The embodiments of the present invention are described in detail below. The following embodiments are implemented based on the technical solutions of the present invention, and provide detailed implementation methods and specific operating procedures. However, the protection scope of the present invention is not limited to the following embodiments.

[0048] Example 1

[0049] The present invention provides a method for designing a high-voltage transmission line, which specifically includes the following steps:

[0050] A simulation model for the optical performance of the "high-voltage transmission line-coating" surface microstructure was established to analyze the coupling effect between particle point scattering within the synergistic coating and surface reflection on the aluminum stranded wire. First, the "high-voltage transmission line-coating" surface was geometrically modeled, and the conductor helical structure parameters and surface microstructure parameters were input to establish a high-precision surface model.

[0051] The surface compensation angle formula can be:

[0052] Microstructure axial compensation angle

[0053] The curvature radius R = 5-20mm, the pitch P = 50-200mm, the non-uniform rational B-spline (NURBS) is used to establish a high-precision surface model, the grid resolution is ≤ 10μm, and the initial value of the surface reflectivity of the aluminum stranded wire is ρ Al =48.9%, pit period Λ=1-5μm, depth h=0.5-2μm.

[0054] Analysis of the optical coupling effect of the "high-voltage transmission line-coating" curved surface; input parameters of the coating material particles, such as particle size d = 100-500nm, volume concentration φ = 20-40%, and gradient distribution Δφ from the surface to the bottom layer = 10-20%.

[0055] The finite difference time domain (FDTD) method is used to calculate the equivalent scattering coefficient S eq , scattering efficiency η sca , grid size Δx=λ min / 20,

[0056]

[0057] in, is the scattered power per unit solid angle, P in is the incident light power;

[0058] Simulate the multiple reflection paths of the wire-coating surface microstructure and calculate the photon paths by Monte Carlo ray tracing. The number of photons is N = 10. 6 , calculate the total reflectivity of the coating;

[0059] ρ total =ρ 颗粒 +ρ Al -ρ 颗粒 ·ρ Al =96.6%

[0060] Among them, ρ 颗粒 Reflectivity contributed by scattering of coating particles, ρ Alis the surface reflectivity of aluminum stranded wire.

[0061] Based on the coupling analysis, the result set of microstructure parameters of “high-voltage transmission line-coating” was obtained, and the multi-objective genetic algorithm NSGA-II (population size = 50, number of iterations = 500) was used to optimize the parameters of the optical performance simulation calculation model.

[0062] The objective function is:

[0063] Maximize the solar band reflectivity ρ total ;

[0064] Maximize the atmospheric window thermal emissivity ε IR ;

[0065] Minimize coating thickness δ;

[0066] The constraints are: δ≤100μm, Λ / h≥1.2.

[0067] Pareto optimal solution set screening criteria: hypervolume index (HV) ≥ 0.8, Λ = 1.0-1.2 μm, h = 0.6-0.8 μm;

[0068] The optimization results are:

[0069] Pareto optimal solution: Λ=1.1μm, h=0.7μm, δ=75μm;

[0070] Prediction performance: ρ total =92.1%,∈ IR =0.92, T s =60℃.

[0071] Prepare coating materials based on the optimization results, and conduct optical performance tests to verify the materials; verify the microstructure morphology, and measure with white light interferometer: Λ 实际 =1.12±0.05μm,h 实际 =0.72±0.03μm, surface roughness Ra=0.15μm.

[0072] The performance test verification is as follows:

[0073]

[0074] Input the predicted values and experimental values, fuse the simulation and experimental data through the physical information neural network, correct the optical simulation calculation model and output the optimization plan.

[0075] Input incident light parameters, coating particle parameters, aluminum surface microstructure parameters, current density, and environmental parameters, and output reflectivity, absorptivity, wire surface temperature, and heat flux density;

[0076] Embed physical constraints; physical constraints include optical constraints;

[0077] The optical constraints are: ρ + α + τ = 1;

[0078] Among them, ρ is the reflectivity, α is the absorptivity, and τ is the transmittance;

[0079] Obtain the loss function of the optical simulation calculation model.

[0080] The loss function is as follows:

[0081]

[0082] in, is the mean square error between the measured value and the predicted value, is the residual of the physical equation;

[0083]

[0084] Among them, λ=0.5, N=1000, M=500.

[0085] Generate a data set based on COMSOL and train with the Adam optimizer, with a prediction error of ≤3%; output the coating parameter optimization solution.

[0086] This design approach reduces coating thickness to 75μm, a 62.5% reduction compared to conventional solutions (>200μm). The conductor's operating temperature is reduced by 13.5°C, while current carrying capacity is increased by 16.2%. Solar reflectivity exceeds 91%, and thermal emissivity exceeds 93%. By coupling point scattering with surface reflection, the conductor's aluminum substrate reflectivity contribution is increased from 10% with conventional technology to 42%. Furthermore, through surface adaptive design, the reflectivity prediction error is controlled to <1%, while the uncompensated model error exceeds 12%.

[0087] Example 2

[0088] Compared with Example 1, the time taken to establish the optical performance simulation calculation model using the finite difference time domain (FDTD) method alone is longer, requiring two days to complete, and has high requirements for equipment, while Example 1 can be completed in just 1-2 hours.

[0089] Example 3

[0090] Compared with the first embodiment, the optical performance simulation calculation model established by the Monte Carlo ray tracing method alone can only be calculated for uniform structures, and cannot be accurately calculated for the special curved surface structure of the high-voltage transmission line, resulting in a large actual error.

[0091] The above describes in detail the preferred embodiments of the present invention. It should be understood that numerous modifications and variations based on the concepts of the present invention are possible by those skilled in the art without inventive effort. Therefore, any technical solution that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for designing a coating for a high-voltage transmission line, characterized in that: The following steps are involved: S1. Establish a simulation model for the optical performance of the curved microstructure of a high-voltage transmission line-coating. Analyze the coupling effect between particle point scattering within the synergistic coating and surface reflection on the aluminum stranded wire surface. Simulate the effects of different coating microstructures on light scattering, thermal emission, and optical coupling. S2. Based on the coupled analysis of step S1, determine the enhancement mechanism of scattering by micro-nano fillers and microstructure design, strengthen the optical resonance effect between the functional fillers and the metal substrate, enhance the thermal radiation capability in the atmospheric window band, obtain the microstructure parameter result set of "high-voltage transmission line-coating", and perform multi-objective parameter optimization; S3. preparing a coating material according to the optimization result of step S2, and performing an optical performance test to verify the material; S4. Input the predicted value and experimental value, fuse the simulation and experimental data through the physical information neural network, correct the optical simulation calculation model and output the optimization solution.

2. The method for designing a coating for a high-voltage transmission line according to claim 1, characterized in that: S1 specifically includes: S11, geometrically modeling the "high-voltage transmission wire-coating" surface, inputting wire spiral structure parameters and surface microstructure parameters, and establishing a high-precision surface model; S12. Analyze the optical coupling effect of the "high-voltage transmission line-coating" curved surface and calculate equivalent interface parameters; the equivalent interface parameters include but are not limited to: equivalent scattering and absorption characteristics; S13. Count the photon paths, calculate the total emissivity, absorptivity and emissivity of the coating, and simulate the multiple reflection paths of the conductor-coating surface microstructure.

3. The design method of a coating for a high-voltage transmission line according to claim 2, characterized in that: The wire helical structure parameters include but are not limited to: curvature radius and pitch; the surface microstructure parameters include but are not limited to: pit period and depth.

4. The method for designing a coating for a high-voltage transmission line according to claim 2, characterized in that: The equivalent scattering parameter calculation process is as follows: Input the parameters of the coating material particles and use the finite difference time domain method to calculate the equivalent scattering coefficient S eq , scattering efficiency η sca , in, is the scattered power per unit solid angle, P in is the incident light power; The parameters of the coating material particles include but are not limited to: particle size, volume concentration, and gradient distribution from the surface layer to the bottom layer.

5. The method for designing a coating for a high-voltage transmission line according to claim 2, characterized in that: Step S13 calculates the total reflectivity of the coating by counting photon paths through Monte Carlo ray tracing; r total =ρ 颗粒 +r 导线 -r 颗粒 ·r 导线 Among them, ρ 颗粒 Reflectivity contributed by scattering of coating particles, ρ 导线 is the reflectivity of the metal surface of the high-voltage transmission line.

6. The method for designing a coating for a high-voltage transmission line according to claim 1, characterized in that: In step S2, a multi-objective genetic algorithm is used to optimize the parameters. The objective function is: Maximize the solar band reflectivity ρ total ; Maximize the atmospheric window thermal emissivity ε IR ; Minimize coating thickness δ; The constraints are: δ≤100μm, Λ / h≥1.2, and Λ is the pit period.

7. The method for designing a coating for a high-voltage transmission line according to claim 1, characterized in that: S4 specifically includes: S41, input incident light parameters, coating particle parameters, aluminum surface microstructure parameters, current density, and environmental parameters, and output reflectivity, absorptivity, conductor surface temperature, and heat flux density; S42, embedding physical constraints; S43, obtaining a loss function of the optical simulation calculation model; The physical constraints include optical constraints; The optical constraint condition is: ρ+α+τ=1; Among them, ρ is the reflectivity, α is the absorptivity, and τ is the transmittance.

8. The method for designing a coating for a high-voltage transmission line according to claim 7, characterized in that: The loss function is as follows: in, is the mean square error between the measured value and the predicted value, is the residual of the physical equation; 9. A coating for high-voltage transmission lines, characterized in that: Made according to any one of the design methods described in claims 1-8.

10. A high voltage transmission line, characterized in that: Comprising the coating according to claim 9.

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