Method for calculating aerodynamic coefficient of split conductor of ultra-high voltage transmission line

Abstract

The invention relates to the technical field of electric power engineering, in particular to an ultra-high voltage transmission line split conductor aerodynamic coefficient calculation method which comprises the following steps: (1) parametric modeling; (2) programmed surrounding flow field analysis; (3) performing automatic data processing and model optimization; (4) calculating aerodynamic coefficients of the split conductors of the ultra-high voltage transmission line under different icing conditions; (5) analyzing an aerodynamic coefficient; and (6) result verification and application optimization. According to the method, rapid and accurate calculation of the aerodynamic characteristics under the complex environment condition is achieved, the calculation efficiency is effectively improved, human intervention is reduced, and reliable technical support is provided for optimization design and safety evaluation of the ultra-high voltage transmission line.

Description

Technical Field

[0001] The invention relates to the technical field of electric power engineering, and in particular to a method for calculating aerodynamic coefficients of split conductors of an ultra-high voltage transmission line. Background Art

[0002] With the continuous growth of global electricity demand, UHV transmission lines have become one of the main means of long-distance power transmission due to their advantages in efficiently transmitting large-capacity electric energy. However, UHV transmission lines face serious safety and stability challenges during operation, especially under extreme climatic conditions such as high altitude, low temperature and ice cover. As an important part of UHV transmission lines, the performance of the aerodynamic characteristics of split conductors in extreme environments is particularly critical.

[0003] Under the action of wind, the split conductors of UHV transmission lines will produce complex aerodynamic effects, which can cause the conductors to vibrate, swing, and even structural damage. Especially under low-temperature icing conditions, the irregular ice layer formed on the surface of the conductors further increases the complexity of the aerodynamic forces and affects the aerodynamic coefficients of the conductors (including drag coefficient, lift coefficient, and torque coefficient). Accurate calculation of these aerodynamic coefficients is crucial to ensure the design safety and operational stability of transmission lines.

[0004] Existing methods for calculating aerodynamic coefficients usually rely on manual modeling and step-by-step analysis, which is not only time-consuming and laborious, but also easily affected by human factors, resulting in insufficient accuracy and consistency of the calculation results. In addition, when dealing with aerodynamic changes under different ice shapes and thicknesses and various wind attack angles, traditional methods often require repeated adjustments to models and calculation parameters, which is inefficient and difficult to meet the needs of large-scale engineering applications.

[0005] In view of this, developing a method that can realize automatic and programmed calculation of the aerodynamic coefficient of split conductors of UHV transmission lines has become the key to solving the above problems. Summary of the invention

[0006] The present invention provides a method for calculating the aerodynamic coefficient of split conductors of an ultra-high voltage transmission line, which aims to achieve efficient and accurate aerodynamic analysis in a parameterized and programmed manner.

[0007] A method for calculating aerodynamic coefficients of split conductors of an ultra-high voltage transmission line according to the present invention comprises the following steps:

[0008] (1) Parametric modeling;

[0009] (2)Programmed flow field analysis;

[0010] (3) Automated data processing and model optimization;

[0011] (4) Calculate the aerodynamic coefficients of split conductors of UHV transmission lines under different icing conditions;

[0012] (5) Aerodynamic coefficient analysis;

[0013] (6) Result verification and application optimization.

[0014] Preferably, in step (1), a mesh model of split conductors of an ultra-high voltage transmission line is established using Gambit software; the model is constructed based on a parametric design method, covering different cross-sectional shapes, lengths, material properties of the conductors, and various possible ice coating shapes and thicknesses; the mesh model is refined, taking into account the complex geometric features of the conductor surface details and the ice coating area.

[0015] Preferably, in step (2), the flow field analysis of the established grid model is performed using Fluent software to obtain the split conductor aerodynamic model;

[0016] First, an automated analysis is performed, including setting different wind attack angles and wind speed conditions, as well as different ice cover shapes and thicknesses. Then, a numerical simulation is performed to calculate the flow pressure field and velocity field of the conductor under various conditions, and to obtain the aerodynamic data of the drag coefficient, lift coefficient, and torque coefficient.

[0017] Preferably, in step (3), after the numerical simulation is generated, the aerodynamic data is processed, including data extraction, format conversion, error analysis and result screening; then the aerodynamic model is calibrated; finally, the model parameters are further adjusted by comparison and verification with the measured data.

[0018] Preferably, in step (4), a calculation program is developed based on the Vb.net programming language to calculate the aerodynamic coefficients of the split conductors of the ultra-high voltage transmission line under different icing conditions, the aerodynamic coefficients including the drag coefficient, lift coefficient and torque coefficient data under different wind attack angles and icing conditions; the calculation program accepts input parameters and automatically calls the optimized aerodynamic model for calculation; the input parameters include wind attack angle, wind speed, ice shape and thickness.

[0019] Preferably, in step (5), the calculation program automatically plots a curve of aerodynamic coefficient variation for analyzing the effects of different ice coating shapes and thicknesses on the aerodynamic characteristics of the conductor.

[0020] Preferably, in step (6), the calculation results are compared with measured data to verify the calculation method; based on the verification results, the calculation method and model parameters are further optimized; and finally, the aerodynamic coefficient calculation method is applied to the design optimization of UHV transmission lines.

[0021] The present invention realizes the rapid and accurate calculation of aerodynamic characteristics under complex environmental conditions by introducing parametric modeling and programmed numerical simulation technology. The present invention targets different ice shapes (such as crescent, D-shape, etc.) and thickness conditions, and rapidly calculates the aerodynamic coefficients of the split conductor, including the drag coefficient, lift coefficient and torque coefficient, through automated modeling, numerical simulation, data processing and result analysis. This effectively improves the calculation efficiency, reduces human intervention, and provides reliable technical support for the optimal design and safety assessment of UHV transmission lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of a method for calculating aerodynamic coefficient of split conductors of a UHV transmission line in an embodiment;

[0023] Figure 2 A schematic diagram of a grid model of split conductors of an ultra-high voltage transmission line based on Gambit software in an embodiment;

[0024] FIG3( a ) is a schematic diagram of the flow pressure field around a crescent-shaped ice-covered six-split conductor at a wind attack angle of 0° in an embodiment;

[0025] FIG3( b ) is a schematic diagram of the flow pressure field around a crescent-shaped ice-covered six-split conductor at a wind attack angle of 45° in an embodiment;

[0026] FIG3( c ) is a schematic diagram of the flow pressure field around a crescent-shaped ice-covered six-split conductor at a 90° wind attack angle in the embodiment;

[0027] FIG3( d ) is a schematic diagram of the flow pressure field around a crescent-shaped ice-covered six-split conductor at a wind attack angle of 135° in an embodiment;

[0028] FIG4( a ) is a schematic diagram of the flow velocity field around a crescent-shaped ice-covered six-split conductor at a wind attack angle of 0° in an embodiment;

[0029] FIG4( b ) is a schematic diagram of the flow velocity field around a crescent-shaped ice-covered six-split conductor at a wind attack angle of 45° in an embodiment;

[0030] FIG4( c ) is a schematic diagram of the flow velocity field of the crescent-shaped ice-covered six-split conductor at a wind attack angle of 90° in the embodiment;

[0031] FIG4(d) is a schematic diagram of the velocity field of the flow around the crescent-shaped ice-covered six-split conductor at a wind attack angle of 135° in the embodiment;

[0032] FIG5( a ) is a schematic diagram of a curve showing a change in the drag coefficient of a split conductor under different wind attack angles in an embodiment;

[0033] FIG5( b ) is a schematic diagram of a curve showing a variation of the lift coefficient of a split conductor under different wind attack angles in an embodiment;

[0034] FIG5( c ) is a schematic diagram of a curve showing a change in the torque coefficient of the split conductor under different wind attack angles in the embodiment. DETAILED DESCRIPTION

[0035] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0036] Example

[0037] like Figure 1 As shown, this embodiment provides a method for calculating the aerodynamic coefficient of a split conductor of an ultra-high voltage transmission line, which includes the following steps:

[0038] (1) Parametric modeling;

[0039] Use Gambit software to build a grid model of split conductors of UHV transmission lines, such as Figure 2 As shown in the figure, the geometric model of the split conductor of the UHV transmission line and its mesh division details are generated based on the Gambit software for subsequent numerical simulation calculations. Figure 2 On the left is the grid around the six-split crescent-shaped ice-covered wire. Figure 2 On the right is the local grid around a single sub-conductor.

[0040] The model is built based on a parametric design method, covering different cross-sectional shapes, lengths, material properties of the conductors, as well as various possible ice shapes (such as crescent and D-shaped) and thicknesses (such as 10mm, 20mm, 30mm).

[0041] To ensure high-precision calculations, the mesh model is refined to take into account the complex geometric features of the conductor surface details and ice-covered areas. The mesh model can quickly generate the corresponding geometric structure by inputting different parameters, reducing the time and error of manual modeling.

[0042] (2)Programmed flow field analysis;

[0043] Fluent software is used to analyze the flow field around the established grid model and obtain the aerodynamic model of the split conductor.

[0044] Through script programming, we first conduct automated analysis, including setting different wind attack angles (such as 0°, 45°, 90°, 135°, etc.) and wind speed conditions, as well as conditions of different ice shapes and thicknesses; then we perform numerical simulations to calculate the flow pressure field and velocity field of the wire under various conditions, and obtain the aerodynamic data of the drag coefficient, lift coefficient, and torque coefficient. All calculation processes are completed automatically, avoiding the tedious steps of manually setting and adjusting parameters.

[0045] Figures 3(a), 3(b), 3(c) and 3(d) are the flow pressure fields around the crescent-shaped iced six-split conductor under typical wind attack angles established based on the Fluent software. They show the flow pressure field distribution around the split conductors of the UHV transmission line under typical wind attack angles, especially the case of the crescent-shaped iced six-split conductor, and are used to analyze the influence of different wind attack angles on the aerodynamic force distribution.

[0046] Figures 4(a), 4(b), 4(c) and 4(d) show the velocity fields around the crescent-shaped ice-covered six-split conductor under typical wind attack angles, showing the distribution of the velocity fields around the split conductor at different wind attack angles, and illustrating the effect of wind speed changes on the aerodynamic characteristics around the conductor.

[0047] (3) Automated data processing and model optimization;

[0048] After the numerical simulation is generated, the aerodynamic data is processed using the built-in data processing program, including data extraction, format conversion, error analysis and result screening; the aerodynamic model is then calibrated using a preset optimization algorithm to improve the accuracy of the model prediction; finally, the model parameters are further adjusted by comparison with the measured data to enable it to more accurately reflect the aerodynamic characteristics under actual environmental conditions.

[0049] (4) Calculate the aerodynamic coefficients of split conductors of UHV transmission lines under different icing conditions;

[0050] A calculation program was developed based on the Vb.net programming language to calculate the aerodynamic coefficients of the split conductors of the UHV transmission line under different icing conditions. The aerodynamic coefficients included the drag coefficient, lift coefficient and torque coefficient data under different wind attack angles and icing conditions. The calculation program accepted input parameters and automatically called the optimized aerodynamic model for calculation. The input parameters included wind attack angle, wind speed, ice shape and thickness.

[0051] The program integrates the entire process of automated operations from data input, calculation execution to result output, supports batch processing of multiple working conditions, and quickly generates curves and related reports on the change of aerodynamic coefficients with wind angle of attack.

[0052] (5) Aerodynamic coefficient analysis;

[0053] The calculation program automatically draws the aerodynamic coefficient variation curve to analyze the influence of different ice shapes and thicknesses on the aerodynamic characteristics of the conductor.

[0054] Based on the calculation results, the adaptability and stability of the design scheme of UHV transmission lines under different climatic conditions can be quickly evaluated, especially considering the impact of icing conditions on the safety performance of conductors.

[0055] As shown in Figures 5(a), 5(b) and 5(c), the aerodynamic coefficient variation curves of the split conductor under different wind attack angles are shown, which show the variation trends of the drag coefficient, lift coefficient and torque coefficient of the split conductor under different wind attack angles, and are used to analyze the influence of wind attack angle on the aerodynamic characteristics of the conductor.

[0056] (6) Result verification and application optimization.

[0057] The calculated results are compared with the measured data to verify the accuracy and reliability of the calculation method. Based on the verification results, the calculation method and model parameters are further optimized to improve the versatility and applicability of the method. Finally, the aerodynamic coefficient calculation method is applied to the design optimization of UHV transmission lines, especially anti-icing measures and conductor structure design under extreme climatic conditions, to provide technical support for the safe and stable operation of the power system.

[0058] Extended Application

[0059] The method of this embodiment is not only applicable to the existing design of UHV transmission lines, but also can be used for the development and evaluation of new conductor designs. By improving the calculation process and optimizing the design parameters, the application scope of this method in different power engineering projects is further expanded.

[0060] The present invention transforms the traditional manual modeling and calculation process into a parametric and programmed automatic operation, significantly improving the calculation efficiency and accuracy, and avoiding a large amount of manual setting and data processing work. By using Gambit software for three-dimensional parametric modeling of the conductor, combined with the programmed fluid dynamics analysis of Fluent software, the aerodynamic characteristics under different wind attack angles and icing conditions are automatically calculated. At the same time, a fast calculation program based on Vb.net was developed to further simplify the calculation process and realize full automation from input parameters to output results.

[0061] Through the method of this embodiment, the design and operation safety of UHV transmission lines can be quickly and accurately evaluated under extreme climatic conditions, especially the analysis of the aerodynamic characteristics of conductors under icing and high wind speed environments. This method is not only applicable to the optimization design of existing UHV transmission lines, but can also be extended to the research and development and evaluation of new conductors, providing scientific basis and technical support for the safe and stable operation of power systems.

[0062] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A method for calculating the aerodynamic coefficient of split conductors of an ultra-high voltage transmission line, characterized in that: The following steps are involved: (1) Parametric modeling; (2)Programmed flow field analysis; (3) Automated data processing and model optimization; (4) Calculate the aerodynamic coefficients of split conductors of UHV transmission lines under different icing conditions; (5) Aerodynamic coefficient analysis; (6) Result verification and application optimization.

2. The method for calculating the aerodynamic coefficient of split conductors of a UHV transmission line according to claim 1, characterized in that: In step (1), the Gambit software is used to establish a mesh model of the split conductor of the UHV transmission line; the model is constructed based on a parametric design method, covering the different cross-sectional shapes, lengths, material properties of the conductors, and various possible ice shapes and thicknesses; the mesh model is refined to take into account the complex geometric features of the conductor surface details and the ice-covered area.

3. The method for calculating the aerodynamic coefficient of split conductors of a UHV transmission line according to claim 2, characterized in that: In step (2), the flow field analysis of the established grid model is performed using Fluent software to obtain the split conductor aerodynamic model; First, an automated analysis is performed, including setting different wind attack angles and wind speed conditions, as well as different ice cover shapes and thicknesses. Then, a numerical simulation is performed to calculate the flow pressure field and velocity field of the conductor under various conditions, and to obtain the aerodynamic data of the drag coefficient, lift coefficient, and torque coefficient.

4. The method for calculating the aerodynamic coefficient of split conductors of a UHV transmission line according to claim 3, characterized in that: In step (3), after the numerical simulation is generated, the aerodynamic data is processed, including data extraction, format conversion, error analysis and result screening; then the aerodynamic model is calibrated; finally, the model parameters are further adjusted by comparing and verifying with the measured data.

5. The method for calculating the aerodynamic coefficient of split conductors of a UHV transmission line according to claim 4, characterized in that: In step (4), a calculation program is developed based on the Vb.net programming language to calculate the aerodynamic coefficients of the split conductors of the ultra-high voltage transmission line under different icing conditions, wherein the aerodynamic coefficients include the drag coefficient, lift coefficient and torque coefficient data under different wind attack angles and icing conditions; the calculation program accepts input parameters and automatically calls the optimized aerodynamic model for calculation; the input parameters include wind attack angle, wind speed, ice shape and thickness.

6. A method for calculating aerodynamic coefficients of split conductors of UHV transmission lines according to claim 5, characterized in that: In step (5), the calculation program automatically draws a curve of aerodynamic coefficient variation, which is used to analyze the influence of different ice shapes and thicknesses on the aerodynamic characteristics of the conductor.

7. A method for calculating aerodynamic coefficients of split conductors of UHV transmission lines according to claim 6, characterized in that: In step (6), the calculation results are compared with the measured data to verify the calculation method; based on the verification results, the calculation method and model parameters are further optimized; and finally, the aerodynamic coefficient calculation method is applied to the design optimization of UHV transmission lines.

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