Cross-section grading anti-vibration design method for key wire of ice-coated power transmission line and related equipment

Abstract

The invention relates to the technical field of wind-induced vibration analysis and anti-vibration design of power transmission lines, and discloses a cross-section grading anti-vibration design method for key wires of an ice-coated power transmission line and related equipment. Constructing a multi-point time history of the non-uniform wind field of the complex terrain based on the tower-line coupled three-dimensional finite element model, and setting load working condition parameters; performing transient dynamic analysis on the tower-line coupled three-dimensional finite element model, and constructing a response database; identifying a key conductor in a conductor group scale based on the response database, and evaluating interphase response discreteness; quantifying the low-order frequency band energy gathering and power selective amplification effect at the key lead scale, and determining a key phase; and identifying a dangerous section in the along-span and component scale, generating a cross-section grading anti-vibration design strategy, and carrying out cross-section grading anti-vibration design on the key conductor of the ice-coated power transmission line according to the cross-section grading anti-vibration design strategy. According to the invention, adaptability and precision of wind-induced vibration protection of the ice-coated power transmission line in the complex terrain are improved.

Description

Technical Field

[0001] This invention relates to the field of wind-induced vibration analysis and vibration prevention design technology for transmission lines, specifically a graded vibration prevention design method and related equipment for key conductor spans of icing transmission lines. Background Technology

[0002] Under the combined influence of strong winter winds and complex terrain wind fields, icing transmission lines are highly susceptible to low-frequency, large-deflection, and long-duration wind-induced vibrations. Typical forms include conductor galloping and similar large-amplitude swaying random vibrations. These wind-induced vibrations significantly increase conductor tension and tower internal forces, and induce prolonged high-level vibrations in localized sections. This leads to rapid accumulation of fatigue damage to fittings and conductors, and in severe cases, can cause conductor strand breakage, insulator string damage, or even tower instability, posing a significant threat to the safe and stable operation of the power grid in icy areas.

[0003] Regarding the wind-induced vibration mechanism of icing conductors, existing technologies have formed a relatively systematic research foundation in related fields such as aerodynamic theory, aeroelastic wind tunnel testing, and finite element numerical analysis. In aeroelastic wind tunnel testing, numerous studies have conducted galloping performance tests on icing conductors and tower-line systems, revealing the influence of key factors such as ice type, wind angle of attack, wind speed range, and multi-span coupling on the initiation wind speed and vibration trajectory. These studies have also clearly pointed out significant differences between multi-span systems and single-span conditions in core characteristics such as critical wind speed and amplitude evolution. In finite element numerical analysis, with the continuous development of tower-line coupled finite element models, researchers have gradually shifted their focus to the overall dynamic response of tower-line systems under the combined action of multiple loads such as wind, ice, earthquakes, and broken conductors. This has confirmed that local analysis of a single tower or single span is insufficient to accurately reflect the structural stress state and vibration characteristics in actual engineering scenarios.

[0004] Despite the progress made in existing research, several technical limitations remain to be addressed in practical engineering applications. These limitations manifest in three main aspects: First, in wind field modeling, existing technologies often employ uniform wind field models along the span or stochastic wind field models that only consider simplified spatial correlations. These models fail to accurately depict the significant three-dimensionality, local amplification effects, and non-uniform distribution characteristics of wind fields in complex terrains such as mountainous areas and canyons, leading to significant discrepancies between wind field simulations and actual operating conditions. Second, regarding structural layout adaptability, existing research primarily focuses on transmission lines with relatively regular span lengths and tower heights. The research on the three-tower, two-span asymmetrical arrangement, where the central tower is located in a valley and the two side towers are located on a high slope or ridge, is not given enough attention. The research results are difficult to apply directly to such irregular lines. Thirdly, in terms of performance evaluation indicators, a considerable number of studies only focus on overall macroscopic indicators such as tower top acceleration, maximum conductor tension, or maximum amplitude at mid-span. They lack multi-scale, fine-grained quantitative characterization of "which specific conductor, which span, and which section along the span" is in an unfavorable working state under the influence of random wind fields for a long time, and cannot provide a targeted basis for precise vibration prevention design.

[0005] Especially in irregular transmission line systems with three towers and two spans and significant tower height differences, the combined effects of non-uniform wind fields and structural geometric asymmetry can easily trigger a phenomenon of "dynamic selective amplification," where the vibrations of a few conductors in the low-order frequency band are continuously amplified, while the vibrations of the remaining conductors remain at background levels for extended periods. Currently, existing technologies lack a systematic framework for identifying critical hazardous conductors, prioritizing phases, and implementing segment-level vibration isolation design, making it difficult to meet the engineering requirements for precise protection of icing transmission lines in complex terrain. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a graded vibration protection design method and related equipment for key conductor segments of icing transmission lines, so as to solve the technical problems of poor adaptability and low accuracy of the existing technology in wind-induced vibration protection of icing transmission lines in complex terrain.

[0007] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a graded vibration isolation design method for key conductor spans of icing transmission lines, comprising: A tower-line coupled three-dimensional finite element model was constructed. Based on the tower-line coupled three-dimensional finite element model, a multi-point time history of a non-uniform wind field in complex terrain was constructed and load condition parameters were set. Transient dynamic analysis was performed on a tower-line coupled three-dimensional finite element model, and a response database was constructed. Identify key conductors at the conductor group scale based on the response database and evaluate the interphase response dispersion. Quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the key phase; By identifying hazardous sections along the span and at the component scale, a graded vibration prevention design strategy for the span is generated, and graded vibration prevention design for the critical conductor span of the icing transmission line is carried out based on the graded vibration prevention design strategy for the span.

[0008] Preferably, the specific process of constructing the tower-line coupled three-dimensional finite element model includes using a combination of pole elements, beam elements and cable elements to establish a three-dimensional tower-line coupled finite element model containing towers, conductors, ground wires and insulator strings, and introducing initial conductor tension, tower top connection constraints and suspension point boundary conditions to make the three-dimensional tower-line coupled finite element model have geometric and boundary condition asymmetry.

[0009] Preferably, the specific process of constructing multi-point time histories of non-uniform wind fields in complex terrain based on a tower-line coupled three-dimensional finite element model and setting load condition parameters includes: By combining digital elevation models and topographic mapping data, the macroscopic and micro-topographic features of the area where the transmission line is located are identified, and the statistical parameters of average wind speed profile, turbulence intensity and integral scale at different heights and cross-sectional locations are determined. Based on the relationship between the target self-spectrum and cross-spectrum, a spatial correlation function is constructed to generate random wind speed time histories of multiple representative nodes, simulating the non-uniform wind speed field in the entire space of the three towers and two spans. The average wind speed profile was defined using a power-law model, the distribution of turbulence intensity along the height was determined based on the reference height turbulence intensity, and the one-dimensional power spectrum of the fluctuating wind was defined using a modified von Kármán model. A transverse equivalent radial uniform icing model is used to characterize the ice layer attached to the conductor and ground wire. The equivalent line mass after icing is calculated, a composite volumetric force density is applied, and the initial sag and tension state are determined by geometric nonlinear static analysis.

[0010] Preferably, the specific process of performing transient dynamic analysis on the tower-line coupled three-dimensional finite element model and constructing a response database includes: A numerical integration method suitable for long-term wind vibration analysis is selected, and the integration time step, total analysis time, damping model, and convergence criterion are set. Apply multiple wind loads and solve the time histories of acceleration, displacement and internal forces of the tower, conductor and ground wire during the analysis period; The original time history is detrended, filtered, and resampled, and then stored in an indexed manner by tower location, span, phase, location along the span, and response type to construct a response database.

[0011] Preferably, the specific process for identifying key conductors at the conductor group scale based on the response database and evaluating the interphase response dispersion includes: The acceleration time histories at the mid-span positions of each span and each phase conductor are extracted, and the root mean square value is calculated as an index of wind-induced vibration intensity. Construct indicators of interphase response dispersion such as maximum / minimum ratio, standard deviation, or coefficient of variation; Set the threshold and sorting rules for critical conductors, screen critical conductors with significantly amplified responses, and determine the comparison conductors.

[0012] Preferably, the specific process of quantifying the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale and determining the key phase includes: Frequency domain analysis was performed on the acceleration time histories of the key conductor and the comparison conductor to calculate the energy spectrum or power spectral density curves and identify the main frequency components and energy distribution characteristics in the low-order frequency band. Within the target low-order frequency band, calculate the frequency band energy and frequency band energy ratio of the key conductor and the comparison conductor; The dynamic selectivity amplification factor is constructed, and the key phase is determined by combining it with a preset threshold.

[0013] Preferably, the specific process of identifying hazardous sections along the span and at the component scale, and generating a segment-level vibration isolation design strategy includes: Calculate the root mean square of acceleration or displacement statistics along the critical conductor at each representative node to identify unfavorable amplitude sections; Extract the peak internal forces of conductors, fittings, and tower components in the area near the tower, and identify the concentrated sections of peak internal forces. Based on relevant indicators, vibration resistance levels are classified, and strategies for damper arrangement, vibration isolation device configuration, and reinforcement verification of near-tower components are proposed.

[0014] Secondly, the present invention also provides a graded vibration prevention design system for critical conductor spans of icing transmission lines, comprising: The model and wind field construction module is used to construct a tower-line coupled three-dimensional finite element model, and based on the tower-line coupled three-dimensional finite element model, construct the multi-point time history of the non-uniform wind field in complex terrain and set the load condition parameters. The dynamic analysis module is used to perform transient dynamic analysis on the tower-line coupled three-dimensional finite element model and build a response database; The conductor group identification module is used to identify key conductors at the conductor group scale based on the response database and to evaluate the interphase response dispersion. The critical conductor quantization module is used to quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale, and to determine the critical phase; The vibration prevention strategy generation module is used to identify dangerous sections along the span and component scale, generate a segment-level vibration prevention design strategy, and carry out segment-level vibration prevention design for critical conductors of icing transmission lines based on the segment-level vibration prevention design strategy.

[0015] Thirdly, the present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the graded vibration prevention design method for key conductor segments of icing transmission lines as described above.

[0016] Fourthly, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the graded vibration prevention design method for key conductor spans of icing transmission lines as described above.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a graded vibration prevention design method for key conductor spans in icing transmission lines. By constructing a tower-line coupled three-dimensional finite element model that closely reflects the complex terrain and asymmetric structural characteristics, and combining multi-point time-history construction of non-uniform wind fields in complex terrain with load condition parameter settings, it overcomes the limitations of traditional wind field modeling (homogenization) and structural analysis (localization), providing a precise computational foundation for subsequent multi-scale dynamic response analysis. Through transient dynamic analysis of the tower-line coupled system and the construction of a structured response database, it overcomes the shortcomings of traditional research that relies on single macroscopic indicators such as tower top acceleration and maximum amplitude at mid-span, providing comprehensive data support for multi-dimensional, fine-grained dynamic response identification. It also identifies key conductors at the conductor group scale and evaluates the interphase response discreteness. This technology enables precise initial screening of conductors with prominent dynamic responses within the overall conductor group, effectively distinguishing the differences in wind-induced vibration responses among conductors of different phases and spans, avoiding the misconception of homogeneous judgment of conductor group responses in traditional methods. It quantifies the energy accumulation and dynamic selective amplification effects in low-order frequency bands at the key conductor scale and identifies key phases, accurately capturing the dynamic selective amplification phenomenon caused by the coupling of non-uniform wind fields and geometric asymmetry under complex terrain, solving the problem that existing technologies cannot locate the core conductor phase controlled by low-order vibrations. Furthermore, it identifies dangerous sections along the span and at the component scale and generates segment-level vibration prevention design strategies, achieving precise location of sections with unfavorable amplitude and areas of concentrated internal forces near the tower, overcoming the limitations of traditional vibration prevention designs that lack tiered targeting and are difficult to adapt to complex terrain lines. Overall, this method conducts a systematic analysis at three levels: conductor group scale, critical conductor scale, and span and component scale. It can comprehensively and accurately identify the dynamically unfavorable conductors, dangerous sections, and near-tower force concentration areas of icy transmission lines in complex terrain. It provides a directly applicable technical process for the segment-level vibration prevention design, critical phase identification, and near-tower component verification of lines in complex icy terrain. It effectively improves the adaptability and accuracy of wind-induced vibration protection for icy transmission lines, significantly enhances the ability of the power grid in icy areas to resist wind-induced vibration risks, and ensures the safe and stable operation of the power grid. Attached Figure Description

[0018] Figure 1 This is a flowchart of the graded vibration prevention design method for key conductor segments of icing transmission lines in an embodiment of the present invention; Figure 2 This is a schematic diagram of tower line modeling in an embodiment of the present invention; Figure 3 This is a schematic diagram of the displacement-time history of the span in the critical conductor in an embodiment of the present invention; Figure 4 This is a schematic diagram of the acceleration-time history of the span in the critical conductor in an embodiment of the present invention; Figure 5 This is a velocity-time history diagram of the span in the critical conductor in an embodiment of the present invention; Figure 6 This is an accelerated spectrum of the span in the critical conductor in an embodiment of the present invention; Figure 7 This is a schematic diagram of the acceleration variation along the critical conductor in an embodiment of the present invention; Figure 8 This is a schematic diagram of the displacement-time history of the conductor span in an embodiment of the present invention; Figure 9 This is a schematic diagram of the velocity-time history of the conductor span in an embodiment of the present invention; Figure 10 This is a schematic diagram of the acceleration-time history of the conductor span in an embodiment of the present invention; Figure 11 This is a schematic diagram of the graded vibration prevention design system for key conductor segments of icing transmission lines in an embodiment of the present invention. The diagram shows: 1. Model and wind field construction module; 2. Dynamic analysis module; 3. Conductor group identification module; 4. Critical conductor quantification module; 5. Vibration prevention strategy generation module. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] The purpose of this invention is to provide a graded vibration protection design method and related equipment for key conductor segments of icing transmission lines, so as to solve the technical problems of poor adaptability and low accuracy of existing technologies in wind-induced vibration protection of icing transmission lines in complex terrain.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See Figure 1 In one embodiment of the present invention, a graded vibration isolation design method for critical conductor spans of icing transmission lines is provided, comprising: Step 1: Construct a tower-line coupled three-dimensional finite element model, and based on the tower-line coupled three-dimensional finite element model, construct a multi-point time history of a non-uniform wind field in complex terrain and set load condition parameters. This embodiment takes a typical mountainous three-tower, two-span icing transmission line as the object. It geometrically abstracts the spatial arrangement of the middle tower being located at a low altitude and the two side towers being located in areas with significant elevation increases. It clarifies the tower height difference, span length combination, phase arrangement of conductors and ground wires, and coordinates of suspension points, providing a topological basis for the tower-line coupled finite element model.

[0023] Based on typical icing conditions and line design data, the icing thickness, density, and ice type parameters of each conductor and ground wire are determined. An equivalent cross-section and material model considering the added mass, stiffness, and aerodynamic characteristic corrections of icing are constructed to reflect the changes in conductor dynamic characteristics caused by ice-wind coupling at the numerical level.

[0024] Specifically, the process of constructing a tower-line coupled three-dimensional finite element model includes using a suitable combination of rod elements, beam elements, and cable elements to establish a three-dimensional tower-line coupled finite element model containing towers, conductors, ground wires, and insulator strings. Initial conductor tension, tower top connection constraints, and suspension point boundary conditions are introduced to give the model significant geometric and boundary condition asymmetry, providing a computational platform for subsequent dynamic analysis. Figure 2 As shown.

[0025] Specifically, the process of constructing multi-point time histories of non-uniform wind fields in complex terrain based on a tower-line coupled three-dimensional finite element model and setting load condition parameters includes: By combining digital elevation models and topographic mapping data, the macro- and micro-topographic features of mountainous or canyon areas where transmission lines are located are identified. Based on specifications or measured data, statistical parameters such as average wind speed profiles, turbulence intensity, and integral scales at different heights and cross-sectional locations are determined to characterize the three-dimensionality and local amplification effect of wind fields under complex terrain.

[0026] Based on the relationship between the target self-spectrum and cross-spectrum, a spatial correlation function is constructed. Taking into account the differences between spans, the differences between phases, and the non-uniformity in the height direction, random wind speed time histories of multiple representative nodes are generated to realize the random simulation of the non-uniform wind speed field in the entire space of the three towers and two spans.

[0027] The average wind speed profile was defined using a power-law model, the distribution of turbulence intensity along the height was determined based on the reference height turbulence intensity, and the one-dimensional power spectrum of the fluctuating wind was defined using a modified von Kármán model. The formula for the power-law model is as follows:

[0028] in, Let z be the average wind speed at height z; z is the target height at which the average wind speed is to be calculated. The average wind speed at the reference height; For reference height; The power exponent characterizing ground roughness.

[0029] Based on typical wind energy and wind engineering literature, the power exponent corresponding to open-low vegetation terrain is generally taken as... The roughness of urban-woodland terrain is significantly greater. Considering the study area's predominantly open mountainous terrain with localized topographic uplift and increased roughness, this application takes... This represents open hilly terrain with moderate roughness.

[0030] The formula for calculating turbulence intensity is as follows:

[0031] in, Let z be the longitudinal turbulence intensity at height z; Let z be the standard deviation of the longitudinal fluctuating wind speed at height z.

[0032] A transverse equivalent radial uniform icing model is used to characterize the ice layer attached to the conductor and ground wire. The equivalent line mass after icing is calculated, a composite volumetric force density is applied, and the initial sag and tension state are determined by geometric nonlinear static analysis.

[0033] In engineering, the turbulence intensity at a reference height of 10m is often used. The "turbulence" level describes the terrain's turbulence level; typical values ​​for flat, open terrain are approximately 0.10–0.15, while complex terrain and near-surface layers in urban areas can reach above 0.20. Referring to the parameter range for "medium-to-high turbulence" conditions in the IEC standard, this paper uses... A value of around 0.14 represents a moderate to high turbulence intensity in mountainous areas.

[0034] The turbulence intensity was simplified by extrapolation along the height using the same exponent as the power law, and the expression is as follows:

[0035] in, The longitudinal turbulence intensity at the reference height; The calculated height is arbitrary; For height The average wind speed at that location.

[0036] This ensures that the variation in turbulence intensity over the tower height range remains on the same order of magnitude as the mean wind profile. The one-dimensional power spectrum of the fluctuating wind employs a modified von Kármán model. For the longitudinal fluctuating velocity at a given height... Its one-dimensional power spectral density is approximately expressed as follows:

[0037] in, For the longitudinal integration scale, this application takes Magnitude The reference wind speed is 10m. This form is consistent with the classical von Kármán turbulence model in terms of asymptotic characteristics at low and high frequencies, and can well characterize the turbulent energy distribution under free-flow conditions.

[0038] In icing conditions, a transverse equivalent radial uniform icing model is used to parametrically characterize the ice layers attached to the conductors and ground wires. First, based on the meteorological icing zone level where the line is located, the climatic icing thickness given in the specifications is used. The nominal radial icing thickness is selected from the wind-ice joint design values ​​for the return period. And by using the relationship between material density and cross-sectional geometry, it is transformed into an incremental expression for the mass per unit length of wire:

[0039] Where D is the nominal outer diameter of the conductor. This is the equivalent ice density.

[0040] Therefore, the equivalent linear mass expression after icing is as follows:

[0041] in, This refers to the quality of the bare wire.

[0042] This treatment treats the ice layer as an equivalent, continuous, and isotropic annular sheath concentric with the conductor, neglecting the second-order effects of higher-order effects such as local ice ridges and eccentric icing on the bending-torsional coupling stiffness. Subsequently, under the influence of gravity, the expression for the combined volumetric force density is constructed as follows:

[0043] An application along the arc length of the conductor to the tower-line coupled system is performed, and the expression is satisfied by geometric nonlinear static analysis. Self-equilibrium displacement field This determines the initial sag and tension state, providing a baseline configuration for subsequent incremental wind vibration analysis.

[0044] It should be noted that actual icing in mountainous areas often exhibits a strongly non-stationary, strongly spatially correlated random field across the entire axis, and its thickness is expressed as follows:

[0045] in, This is a zero-mean random disturbance term. If this random field is also included in the modeling of wind field spatial inhomogeneity, it will introduce dual random source coupling and a high-dimensional parameter space in the numerical model, significantly increasing the difficulty of mechanism interpretation.

[0046] Step 2: Perform transient dynamic analysis on the tower-line coupled three-dimensional finite element model and construct a response database; Specifically, the process is as follows: Numerical integration methods suitable for long-term wind vibration analysis are selected, and the integration time step, total analysis time, damping model, and convergence criterion are set to ensure the numerical stability and computational accuracy of the transient dynamic solution of the tower-line system under multi-point non-uniform wind field excitation.

[0047] Multi-point wind loads were applied to the constructed finite element model, and the acceleration, displacement, and internal force time histories of the tower, conductor, and ground wire were solved throughout the analysis period. Multi-channel response data covering each span, each phase, and typical nodes along the span were obtained, such as... Figure 3 and Figure 4 As shown.

[0048] The original time history is detrended, filtered, and resampled as necessary. It is then indexed and stored according to key information such as "tower location – span – phase – location along the span – response type," constructing an efficiently accessible response database. This provides a unified data foundation for subsequent multi-scale identification and statistical analysis. Figure 5 As shown.

[0049] Step 3: Identify key conductors at the conductor group scale based on the response database and evaluate the interphase response dispersion; Specifically, the process is as follows: At the conductor group scale, the acceleration time histories at the mid-span positions of each span and phase conductor are extracted, and their root mean square values ​​are calculated as wind-induced vibration intensity indicators. This yields preliminary quantitative comparison results of wind-induced vibration levels of different conductors under the same external wind field excitation. Figure 6 and Figure 7 As shown.

[0050] Based on the root mean square results of the mid-span acceleration of each conductor, inter-phase response dispersion indices such as maximum / minimum ratio, standard deviation, or coefficient of variation are constructed to quantitatively characterize the non-uniformity and degree of difference in wind-induced vibration response within the conductor group across phases and spans.

[0051] Based on the root mean square acceleration at mid-span and the discreteness of interphase response, a threshold and ranking rules for determining critical conductors were set. Conductors with significantly amplified responses were selected from multiple iced conductors as critical conductors. The conductor with the weakest response or a representative weak-response conductor was chosen as a comparison object, providing a set of target conductors for subsequent frequency domain analysis and selective amplification quantization. Figure 8 and Figure 9 As shown.

[0052] Step 4: Quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the key phase; Specifically, the process is as follows: Frequency domain analysis was performed on the acceleration time histories of the key conductor and the comparison conductor to calculate their energy spectrum or power spectral density curves, and to identify the main frequency components and energy distribution characteristics of each in the low-order frequency band and its neighborhood.

[0053] Within the target low-order frequency band of 0.5–2Hz, the frequency band energy and frequency band energy ratio of the key conductor and the comparison conductor are calculated to quantitatively characterize the contribution of the low-order vibration components of each conductor to the overall response and the energy accumulation characteristics.

[0054] The "dynamic selective amplification factor" is constructed between the critical conductor and the control conductor, including the low-order frequency band energy ratio and energy proportion ratio. Combined with preset thresholds, this provides the final identification criteria for the critical phase, determining the conductor phase controlled by low-order vibration selective amplification under the coupling effect of geometric asymmetry and non-uniform wind fields. This provides precise targets for vibration damping design and monitoring point placement. Figure 10 As shown.

[0055] Step 5: Identify hazardous sections along the span and at the component scale, generate a segment-level vibration prevention design strategy, and carry out segment-level vibration prevention design for critical conductors of icing transmission lines based on the segment-level vibration prevention design strategy.

[0056] Specifically, the specific process includes: At the critical conductor scale, the root mean square of acceleration or displacement statistics of representative nodes along the span are calculated to form the amplitude distribution curve along the span, identify the "unfavorable amplitude section" that has been at a high amplitude level for a long time, and analyze its spatial relationship with the mid-span and near-tower areas.

[0057] The peak values ​​of internal forces in conductors, fittings, and tower components near the three-base tower were extracted, and their distribution characteristics along the tower height and along the line were statistically analyzed. The component sections with significantly concentrated peak internal forces were identified and spatially compared with the unfavorable amplitude sections to reveal the possible misalignment between the amplitude control zone and the internal force control zone.

[0058] Based on indicators such as the dynamic selectivity amplification factor, the length of the unfavorable section of amplitude along the span, and the peak level of internal force, the conductors of each span in the three-tower two-span system are divided into different vibration protection levels. A damper arrangement, vibration protection device configuration, and near-tower component strengthening verification strategy are proposed for key conductors and key sections, forming a segment-level vibration protection design method suitable for icy transmission lines in complex terrain in icy areas.

[0059] In summary, this embodiment provides a graded vibration isolation design method for critical conductor spans of icing transmission lines. By constructing a tower-line coupled three-dimensional finite element model, introducing multi-point non-uniform wind field time histories, and conducting long-term transient analysis, it identifies dynamically unfavorable objects at multiple scales: conductor groups, individual conductors, and along the span and structural members. This provides a systematic technical means for vibration isolation configuration and near-tower component safety verification of transmission lines in complex icy terrain. This method can systematically identify dynamically unfavorable conductors, dangerous sections, and near-tower force concentration areas at three levels: conductor group scale, critical conductor scale, and along the span and structural member scale. It provides a directly applicable technical process for graded vibration isolation design, critical phase identification, and near-tower component verification of transmission lines in complex icy terrain.

[0060] Example 2 according to Figure 11 As shown, the present invention also provides a graded vibration isolation design system for critical conductor spans of icing transmission lines, comprising: Model and wind field construction module 1 is used to construct a tower-line coupled three-dimensional finite element model, construct a multi-point time history of a non-uniform wind field in complex terrain based on the tower-line coupled three-dimensional finite element model, and set load condition parameters. Dynamic analysis module 2 is used to perform transient dynamic analysis on the tower-line coupled three-dimensional finite element model and build a response database; The conductor group identification module 3 is used to identify key conductors at the conductor group scale based on the response database and to evaluate the interphase response dispersion. Critical conductor quantization module 4 is used to quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the critical phase; The vibration prevention strategy generation module 5 is used to identify dangerous sections along the span and component scale, generate a segment-level vibration prevention design strategy, and carry out segment-level vibration prevention design for key conductors of icing transmission lines based on the segment-level vibration prevention design strategy.

[0061] Example 3 The present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, such as a graded vibration prevention design program for critical conductor segments of icing transmission lines.

[0062] When the processor executes the computer program, it implements the steps of the above-mentioned graded vibration prevention design method for key conductor segments of icing transmission lines, for example: A tower-line coupled three-dimensional finite element model was constructed. Based on the tower-line coupled three-dimensional finite element model, a multi-point time history of a non-uniform wind field in complex terrain was constructed and load condition parameters were set. Transient dynamic analysis was performed on a tower-line coupled three-dimensional finite element model, and a response database was constructed. Identify key conductors at the conductor group scale based on the response database and evaluate the interphase response dispersion. Quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the key phase; By identifying hazardous sections along the span and at the component scale, a graded vibration prevention design strategy for the span is generated, and graded vibration prevention design for the critical conductor span of the icing transmission line is carried out based on the graded vibration prevention design strategy for the span.

[0063] Alternatively, when the processor executes the computer program, it implements the functions of each module in the above system, for example: Model and wind field construction module 1 is used to construct a tower-line coupled three-dimensional finite element model, construct a multi-point time history of a non-uniform wind field in complex terrain based on the tower-line coupled three-dimensional finite element model, and set load condition parameters. Dynamic analysis module 2 is used to perform transient dynamic analysis on the tower-line coupled three-dimensional finite element model and build a response database; The conductor group identification module 3 is used to identify key conductors at the conductor group scale based on the response database and to evaluate the interphase response dispersion. Critical conductor quantization module 4 is used to quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the critical phase; The vibration prevention strategy generation module 5 is used to identify dangerous sections along the span and component scale, generate a segment-level vibration prevention design strategy, and carry out segment-level vibration prevention design for key conductors of icing transmission lines based on the segment-level vibration prevention design strategy.

[0064] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the mobile terminal.

[0065] For example, the computer program can be divided into a model and wind field construction module 1, a dynamic analysis module 2, a conductor group identification module 3, a key conductor quantification module 4, and a vibration prevention strategy generation module 5; The specific functions of each module are as follows: Model and wind field construction module 1 is used to construct a tower-line coupled three-dimensional finite element model, construct a multi-point time history of a non-uniform wind field in complex terrain based on the tower-line coupled three-dimensional finite element model, and set load condition parameters. Dynamic analysis module 2 is used to perform transient dynamic analysis on the tower-line coupled three-dimensional finite element model and build a response database; The conductor group identification module 3 is used to identify key conductors at the conductor group scale based on the response database and to evaluate the interphase response dispersion. Critical conductor quantization module 4 is used to quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the critical phase; The vibration prevention strategy generation module 5 is used to identify dangerous sections along the span and component scale, generate a segment-level vibration prevention design strategy, and carry out segment-level vibration prevention design for key conductors of icing transmission lines based on the segment-level vibration prevention design strategy.

[0066] The mobile terminal can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The mobile terminal may include, but is not limited to, a processor and memory.

[0067] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the mobile terminal, connecting various parts of the mobile terminal via various interfaces and lines.

[0068] The memory can be used to store the computer program and / or module. The processor implements various functions of the mobile terminal by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0069] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function (such as sound playback, image playback, etc.). The data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory and non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital cards (SD cards), flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0070] Example 4 The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the graded vibration prevention design method for key conductor spans of icing transmission lines.

[0071] If the modules / units integrated in the mobile terminal are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0072] Based on this understanding, all or part of the processes in the above method can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-described aggregated reinforcement learning resource scheduling method. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate form.

[0073] The computer-readable medium may include any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0074] It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A graded vibration isolation design method for key conductor spans of icing transmission lines, characterized in that, include: A tower-line coupled three-dimensional finite element model was constructed. Based on the tower-line coupled three-dimensional finite element model, a multi-point time history of a non-uniform wind field in complex terrain was constructed and load condition parameters were set. Transient dynamic analysis was performed on a tower-line coupled three-dimensional finite element model, and a response database was constructed. Identify key conductors at the conductor group scale based on the response database and evaluate the interphase response dispersion. Quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale to determine the key phase; By identifying hazardous sections along the span and at the component scale, a graded vibration prevention design strategy for the span is generated, and graded vibration prevention design for the critical conductors of the icing transmission line is carried out based on the graded vibration prevention design strategy for the span.

2. The graded vibration isolation design method for key conductor spans of icing transmission lines according to claim 1, characterized in that, The specific process of constructing a tower-line coupled three-dimensional finite element model includes using a combination of pole elements, beam elements and cable elements to establish a three-dimensional tower-line coupled finite element model containing towers, conductors, ground wires and insulator strings. Initial tension of the conductor, connection constraints at the top of the tower and boundary conditions at the suspension point are introduced to make the three-dimensional tower-line coupled finite element model have geometric and boundary condition asymmetry.

3. The graded vibration isolation design method for key conductor spans of icing transmission lines according to claim 1, characterized in that, The specific process of constructing multi-point time histories of non-uniform wind fields in complex terrain and setting load condition parameters based on a tower-line coupled three-dimensional finite element model includes: By combining digital elevation models and topographic mapping data, the macroscopic and micro-topographic features of the area where the transmission line is located are identified, and the statistical parameters of average wind speed profile, turbulence intensity and integral scale at different heights and cross-sectional locations are determined. Based on the relationship between the target self-spectrum and cross-spectrum, a spatial correlation function is constructed to generate random wind speed time histories of multiple representative nodes, simulating the non-uniform wind speed field in the entire space of the three towers and two spans. The average wind speed profile was defined using a power-law model, the distribution of turbulence intensity along the height was determined based on the reference height turbulence intensity, and the one-dimensional power spectrum of the fluctuating wind was defined using a modified von Kármán model. A transverse equivalent radial uniform icing model is used to characterize the ice layer attached to the conductor and ground wire. The equivalent line mass after icing is calculated, a composite volumetric force density is applied, and the initial sag and tension state are determined by geometric nonlinear static analysis.

4. The graded vibration isolation design method for key conductor spans of icing transmission lines according to claim 1, characterized in that, The specific process of performing transient dynamic analysis on a tower-line coupled three-dimensional finite element model and constructing a response database includes: A numerical integration method suitable for long-term wind vibration analysis is selected, and the integration time step, total analysis time, damping model, and convergence criterion are set. Apply multiple wind loads and solve the time histories of acceleration, displacement and internal forces of the tower, conductor and ground wire during the analysis period; The original time history is detrended, filtered, and resampled, and then stored in an indexed manner by tower location, span, phase, location along the span, and response type to construct a response database.

5. The graded vibration isolation design method for key conductor spans of icing transmission lines according to claim 1, characterized in that, The specific process of identifying key conductors at the conductor group scale based on a response database and evaluating the interphase response dispersion includes: The acceleration time histories at the mid-span positions of each span and each phase conductor are extracted, and the root mean square value is calculated as an index of wind-induced vibration intensity. Construct indicators of interphase response dispersion such as maximum / minimum ratio, standard deviation, or coefficient of variation; Set the threshold and sorting rules for critical conductors, screen critical conductors with significantly amplified responses, and determine the comparison conductors.

6. The graded vibration isolation design method for key conductor spans of icing transmission lines according to claim 1, characterized in that, The specific process of quantifying low-order frequency energy accumulation and dynamic selective amplification effects at the critical conductor scale, and determining the key phase, includes: Frequency domain analysis was performed on the acceleration time histories of the key conductor and the comparison conductor to calculate the energy spectrum or power spectral density curves and identify the main frequency components and energy distribution characteristics in the low-order frequency band. Within the target low-order frequency band, calculate the frequency band energy and frequency band energy ratio of the key conductor and the comparison conductor; The dynamic selectivity amplification factor is constructed, and the key phase is determined by combining it with a preset threshold.

7. The graded vibration isolation design method for key conductor spans of icing transmission lines according to claim 1, characterized in that, The specific process of identifying hazardous sections along the span and at the component scale, and generating a graded vibration isolation design strategy for the span, includes: Calculate the root mean square of acceleration or displacement statistics along the critical conductor at each representative node to identify unfavorable amplitude sections; Extract the peak internal forces of conductors, fittings, and tower components in the area near the tower, and identify the concentrated sections of peak internal forces. Based on relevant indicators, vibration resistance levels are classified, and strategies for damper arrangement, vibration isolation device configuration, and reinforcement verification of near-tower components are proposed.

8. A graded vibration damping design system for key conductor spans in icing transmission lines, characterized in that, include: The model and wind field construction module is used to construct a tower-line coupled three-dimensional finite element model, and based on the tower-line coupled three-dimensional finite element model, construct the multi-point time history of the non-uniform wind field in complex terrain and set the load condition parameters. The dynamic analysis module is used to perform transient dynamic analysis on the tower-line coupled three-dimensional finite element model and build a response database; The conductor group identification module is used to identify key conductors at the conductor group scale based on the response database and to evaluate the interphase response dispersion. The critical conductor quantization module is used to quantify the energy accumulation and dynamic selective amplification effect in the low-order frequency band at the critical conductor scale, and to determine the critical phase; The vibration prevention strategy generation module is used to identify dangerous sections along the span and component scale, generate a segment-level vibration prevention design strategy, and carry out segment-level vibration prevention design for critical conductors of icing transmission lines based on the segment-level vibration prevention design strategy.

9. A mobile terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the graded vibration prevention design method for critical conductor segments of icing transmission lines as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the graded vibration prevention design method for critical conductor segments of icing transmission lines as described in any one of claims 1-7.

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