An overhead ground wire lightning resistance performance verification method based on operation characteristic comparison
Patent Information
- Application Number
- CN202611075702.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-20
- Publication Date
- 2026-10-20
AI Technical Summary
[0010]本发明的一个目的在于，提供一种基于运行特性对比的架空地线耐雷性能验证方法，能解决现有架空地线耐雷性能评估方法因忽略实际运行特性而导致的评估结果静态、理想化、与真实情况偏差大的问题
[0029]本发明的有益效果在于：提供一种基于运行特性对比的架空地线耐雷性能验证方法，包括：
Smart Images
Figure FT_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of power operation and maintenance technology, and in particular to a method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison. Background Technology
[0002] Overhead transmission lines are a crucial component of the power system, and their safe and stable operation directly impacts the reliability of the power grid. Overhead ground wires (also known as lightning protection wires) are installed above transmission lines, their primary function being to intercept direct lightning strikes and safely discharge the lightning current into the ground, thus protecting the transmission lines from lightning damage. Therefore, the lightning resistance performance of overhead ground wires is a key indicator for evaluating the lightning protection level of transmission lines.
[0003] Traditional methods for evaluating the lightning withstand performance of overhead ground wires primarily rely on theoretical calculations and laboratory simulations. Theoretical calculations are typically based on standard procedures or electromagnetic transient simulations, calculating indicators such as the ground wire's current shunting coefficient and backflashover withstand level by setting standard lightning current waveforms and line parameters. However, this method has the following limitations:
[0004] (1) Idealized assumptions: Theoretical calculations often ignore the changes in mechanical and electrical characteristics of the ground wire caused by long-term wind vibration, icing, corrosion and other factors during actual operation, such as increased ground wire sag, increased surface roughness and increased resistivity, which leads to a large deviation between the calculation results and the actual situation.
[0005] (2) Static assessment: Traditional methods are mostly one-time assessments, which cannot reflect the dynamic evolution of the lightning resistance performance of the ground wire throughout the entire service life, and are difficult to guide the differentiated operation and maintenance and transformation of the line.
[0006] (3) Lack of empirical evidence: Although laboratory simulations are controllable, their environmental conditions differ from the real complex field operating environment, making it difficult to fully reproduce the multi-physics coupling effect during lightning strikes.
[0007] With the development of online monitoring technology, although some operational data (such as lightning current amplitude and number of lightning strikes) can be obtained, these data are usually used in isolation to statistically analyze the lightning trip rate. They fail to establish an effective correlation with the operating characteristics of the ground wire itself (such as sag, tension, temperature, vibration, etc.), thus making it impossible to verify the true state and changing trend of the ground wire's lightning resistance performance from a mechanistic perspective.
[0008] Therefore, there is an urgent need for a method that can dynamically and accurately verify the lightning resistance performance of overhead ground wires by combining their actual operating characteristics, so as to make up for the shortcomings of existing technologies and provide a scientific basis for line lightning protection design and operation and maintenance.
[0009] The background information disclosed herein is for the purpose of assisting in understanding the background of this invention and does not constitute an admission of prior art known to those skilled in the art. Summary of the Invention
[0010] One objective of this invention is to provide a method for verifying the lightning resistance performance of overhead ground wires based on operational characteristic comparison, which can solve the problem that existing methods for evaluating the lightning resistance performance of overhead ground wires result in static, idealized evaluation results with large deviations from reality due to neglecting actual operational characteristics.
[0011] To achieve the above objectives, this invention provides a method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison, comprising:
[0012] Step S1: Obtain the operating characteristic parameters of the overhead ground wire to be verified at multiple historical time points. The operating characteristic parameters include at least the ground wire sag, ground wire tension, and ground wire temperature.
[0013] Step S2: Based on the operating characteristic parameters of the multiple historical time points, establish a model for the evolution of the ground wire operating characteristics over time;
[0014] Step S3: Obtain the instantaneous operating characteristic parameters of the overhead ground wire to be verified when the preset lightning strike event occurs, and record them as the lightning strike time parameters;
[0015] Step S4: Input the lightning strike time parameter into the evolution model to predict the theoretical lightning resistance performance index of the ground wire at the lightning strike time, which is denoted as the first performance index.
[0016] Step S5: Obtain the actual operating characteristic parameters of the ground wire under the same working conditions after the lightning strike event, and invert the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters, which is recorded as the second performance index.
[0017] Step S6: Compare the first performance index with the second performance index. If the deviation between the two exceeds a preset threshold, it is determined that the lightning resistance performance of the overhead ground wire has deteriorated; otherwise, it is determined to be normal.
[0018] Optionally, in step S1, the operating characteristic parameters may further include at least one of the following: the degree of corrosion on the ground wire surface, the ground wire vibration frequency, and the amplitude.
[0019] Optionally, in step S1, the operating characteristic parameters are obtained in real time through distributed optical fiber sensors or wireless sensor networks deployed on the ground wire.
[0020] Optionally, in step S2, the evolution model is a regression model based on time series analysis or a prediction model based on machine learning.
[0021] Optionally, in step S3, the preset lightning strike event is identified and triggered by a lightning location system or a lightning counter installed on the tower.
[0022] Optionally, in step S4, the evolution model also inputs recent meteorological condition parameters prior to the lightning strike event to improve the prediction accuracy of the first performance index.
[0023] Optionally, in step S4, the theoretical lightning resistance performance index includes at least one of the following: the ground wire current shunting coefficient, the ground wire backflash lightning resistance level, and the ground wire thermal stability.
[0024] Optionally, in step S5, obtaining the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters specifically includes:
[0025] Based on the sag change and tensile stress distribution of the ground wire after the lightning strike, and combined with the material properties of the ground wire, the actual energy absorbed by the ground wire under the lightning strike is calculated, and its thermal stability is evaluated accordingly.
[0026] Optionally, in step S6, the preset threshold is dynamically adjusted according to the importance level of the line and the service life of the ground wire.
[0027] Optionally, the method further includes:
[0028] Step S7: If it is determined that the lightning protection performance has deteriorated, an early warning message is generated and a corresponding operation and maintenance strategy is recommended. The operation and maintenance strategy includes adjusting the ground wire sag, replacing the ground wire, or installing lightning protection auxiliary devices.
[0029] The beneficial effects of this invention are: it provides a method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison, comprising:
[0030] Step S1: Obtain the operational characteristic parameters of the overhead ground wire to be verified at multiple historical time points. These operational characteristic parameters include at least ground wire sag, ground wire tension, and ground wire temperature. These parameters can be acquired in real time through distributed fiber optic sensors or wireless sensor networks deployed on the ground wire, reflecting the long-term changes of the ground wire in the actual service environment.
[0031] Step S2: Based on the operating characteristic parameters of the multiple historical time points, establish an evolution model of the ground wire operating characteristics over time. This model can be a regression model based on time series analysis or a prediction model based on machine learning, used to describe the dynamic evolution of the mechanical and thermodynamic states of the ground wire.
[0032] Step S3: Obtain the instantaneous operating characteristic parameters of the overhead ground wire to be verified when a preset lightning strike event occurs, and record them as the lightning strike time parameters. The lightning strike event can be identified and triggered by a lightning positioning system or a lightning counter on the tower.
[0033] Step S4: Input the lightning strike time parameter into the evolution model to predict the theoretical lightning resistance performance index of the ground wire at the lightning strike time, which is denoted as the first performance index. The theoretical lightning resistance performance index includes at least one of the ground wire current shunting coefficient, ground wire backflash lightning resistance level, and ground wire thermal stability.
[0034] Step S5: Obtain the actual operating characteristic parameters of the ground wire under the same working conditions after the lightning strike event, and invert the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters, which is recorded as the second performance index.
[0035] Step S6: Compare the first performance index with the second performance index. If the deviation between the two exceeds a preset threshold, it is determined that the lightning resistance performance of the overhead ground wire has deteriorated; otherwise, it is determined to be normal.
[0036] Through the above process, this method overcomes the limitations of idealized assumptions in traditional theoretical calculations, establishes a dynamic comparison mechanism using actual operating data, and can promptly detect the hidden degradation of ground wire lightning resistance performance, providing objective and real-time decision-making basis for line lightning protection operation and maintenance, and significantly improving the accuracy and practicality of the assessment.
[0037] Therefore, the overhead ground wire lightning resistance performance verification method based on operational characteristic comparison provided by the present invention can solve the problem that the existing overhead ground wire lightning resistance performance evaluation methods are static, idealized, and have large deviations from the actual situation due to ignoring actual operational characteristics. Attached Figure Description
[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0039] Figure 1 A flowchart of a method for verifying the lightning resistance performance of overhead ground wires based on operational characteristic comparison, provided for an embodiment. Detailed Implementation
[0040] In this invention, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of the invention. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this invention, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form a corresponding implementable technical solution.
[0041] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit the invention.
[0042] In the description of this invention, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " generally indicates that the preceding and following objects have an "or" logical relationship.
[0043] In this invention, terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy, or order between these entities or operations.
[0044] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this invention is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.
[0045] Similar to the understanding in the Examination Guidelines, in this invention, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments of this invention, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.
[0046] In the description of the embodiments of the present invention, the spatial related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of the present invention or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.
[0047] Unless otherwise explicitly stated or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this invention, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this invention according to the specific circumstances.
[0048] See Figure 1 This embodiment provides a method for verifying the lightning resistance performance of overhead ground wires based on operational characteristic comparison, including:
[0049] Step S1: Obtain the operational characteristic parameters of the overhead ground wire to be verified at multiple historical time points. These operational characteristic parameters include at least ground wire sag, ground wire tension, and ground wire temperature. These parameters can be acquired in real time through distributed fiber optic sensors or wireless sensor networks deployed on the ground wire, reflecting the long-term changes of the ground wire in the actual service environment.
[0050] Step S2: Based on the operating characteristic parameters of the multiple historical time points, establish an evolution model of the ground wire operating characteristics over time. This model can be a regression model based on time series analysis or a prediction model based on machine learning, used to describe the dynamic evolution of the mechanical and thermodynamic states of the ground wire.
[0051] Step S3: Obtain the instantaneous operating characteristic parameters of the overhead ground wire to be verified when a preset lightning strike event occurs, and record them as the lightning strike time parameters. The lightning strike event can be identified and triggered by a lightning positioning system or a lightning counter on the tower.
[0052] Step S4: Input the lightning strike time parameter into the evolution model to predict the theoretical lightning resistance performance index of the ground wire at the lightning strike time, which is denoted as the first performance index. The theoretical lightning resistance performance index includes at least one of the ground wire current shunting coefficient, ground wire backflash lightning resistance level, and ground wire thermal stability.
[0053] Step S5: Obtain the actual operating characteristic parameters of the ground wire under the same working conditions after the lightning strike event, and invert the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters, which is recorded as the second performance index.
[0054] Step S6: Compare the first performance index with the second performance index. If the deviation between the two exceeds a preset threshold, it is determined that the lightning resistance performance of the overhead ground wire has deteriorated; otherwise, it is determined to be normal.
[0055] Through the above process, this method overcomes the limitations of idealized assumptions in traditional theoretical calculations, establishes a dynamic comparison mechanism using actual operating data, and can promptly detect the hidden degradation of ground wire lightning resistance performance, providing objective and real-time decision-making basis for line lightning protection operation and maintenance, and significantly improving the accuracy and practicality of the assessment.
[0056] To further enrich the dimensions of the operational characteristic parameters and improve the accuracy of the evolution model in depicting changes in the ground wire state, this embodiment extends step S1. The operational characteristic parameters also include at least one of the following: ground wire surface corrosion degree, ground wire vibration frequency, and amplitude. The ground wire surface corrosion degree can be obtained through image recognition or electrochemical sensors, while the vibration frequency and amplitude can be measured by accelerometers or fiber optic vibration sensors. These parameters reflect the material degradation of the ground wire due to long-term exposure to the atmospheric environment, as well as dynamic behaviors such as wind vibration and galloping. These factors all affect the mechanical strength and electrical connection reliability of the ground wire, thus indirectly affecting its lightning resistance performance. By incorporating these parameters into the evolution model, the model can more comprehensively capture subtle changes in the ground wire's operational characteristics, thereby improving the prediction accuracy of the subsequent first performance index.
[0057] Optionally, the operational characteristic parameters are acquired in real time through distributed fiber optic sensors or wireless sensor networks deployed on the ground wire. Distributed fiber optic sensors have the advantages of resistance to electromagnetic interference and long-distance continuous measurement, and can simultaneously sense the temperature, strain, and vibration of the ground wire; wireless sensor networks are easy to deploy at key nodes such as poles and towers, achieving low-cost, high-density data aggregation. Using one or a combination of these two methods can achieve all-weather, automated monitoring of the ground wire's operational characteristics, avoiding the lag and blind spots of manual inspections, ensuring that the temporal resolution and spatial coverage of historical data meet the requirements for training the evolution model, and providing a reliable data foundation for subsequent steps.
[0058] This embodiment provides two optional implementations of the method for constructing the evolution model in step S2. The evolution model can be a regression model based on time series analysis or a predictive model based on machine learning. Regression models based on time series analysis (such as ARIMA, exponential smoothing, etc.) are suitable for scenarios with relatively small amounts of data and obvious trends, and can concisely fit the changes in parameters such as ground wire sag and tension over time. Predictive models based on machine learning (such as LSTM, random forest, XGBoost, etc.) are more suitable for handling multivariate, nonlinear, and complex interaction situations, and can automatically learn implicit patterns in historical data. Regardless of the model used, the core objective is to calculate the state of the ground wire at any future moment (especially at the instant of a lightning strike) based on historical operating characteristic parameters, thereby supporting subsequent theoretical lightning resistance performance prediction. Users can flexibly choose according to actual data characteristics and computing resources to achieve a balance between accuracy and efficiency.
[0059] In this embodiment, the preset lightning strike event is identified and triggered by a lightning location system or a lightning counter installed on a tower. The lightning location system can monitor lightning activity in the area in real time, accurately locate the coordinates and time of the lightning strike point, and automatically trigger the data acquisition process when the lightning strike point is detected to be near the corridor of the overhead ground wire to be verified. The lightning counter is directly installed on the tower and records the time and approximate amplitude of the lightning strike by sensing the changes in the magnetic or electric field generated by the lightning current. Both methods can ensure that the instantaneous operating characteristic parameters of the ground wire (i.e., the lightning strike time parameters) are obtained in a timely manner at the moment the lightning strike event occurs, avoiding data distortion caused by time asynchrony. This step is a key prerequisite for realizing the "comparison before and after lightning strike", ensuring that the first performance index and the second performance index correspond to the same lightning strike event, thus giving the subsequent comparison clear physical meaning.
[0060] To further improve the prediction accuracy of the first performance index, this embodiment optimizes step S4. The evolution model also inputs recent meteorological condition parameters prior to the lightning strike. Specifically, while inputting the lightning strike time parameters into the evolution model, meteorological data from a period prior to the lightning strike (e.g., the previous 24 hours or week) are simultaneously input. These meteorological condition parameters include, but are not limited to, ambient temperature, wind speed, wind direction, humidity, solar radiation intensity, and icing conditions. These meteorological conditions are important external factors affecting ground wire sag, tension, and temperature. For example, high temperatures increase ground wire sag and decrease tension, strong winds intensify ground wire vibration, and icing significantly increases the ground wire load. By incorporating recent meteorological condition parameters into the evolution model, the model can fully consider the immediate impact of the external environment when predicting theoretical lightning resistance performance indicators, making the prediction results closer to the actual physical state of the ground wire at the time of the lightning strike. This reduces the systematic deviation between the first and second performance indicators and improves the reliability of lightning resistance performance determination.
[0061] In this embodiment, the theoretical lightning resistance performance indicators include at least one of the following: ground wire shunting coefficient, ground wire backflashover resistance level, and ground wire thermal stability. The ground wire shunting coefficient refers to the proportion of lightning current shunted from the ground wire to adjacent towers when a lightning strikes a tower or ground wire; this coefficient directly affects the lightning resistance level of the ground wire and towers. The ground wire backflashover resistance level refers to the maximum lightning current amplitude that the ground wire can withstand without flashover, and is a key parameter for evaluating the ground wire's insulation coordination capability. The ground wire thermal stability refers to the ground wire's ability to withstand a lightning current without exceeding the material's allowable temperature rise, reflecting the ground wire's margin against the thermal effects of lightning current. These three indicators characterize the ground wire's lightning resistance performance from three dimensions: current distribution, insulation withstand capability, and heat capacity. In practical applications, one or more of these indicators can be selected as comparison objects based on the line's voltage level, ground wire type, and operating environment to comprehensively evaluate the ground wire's performance in lightning strike events.
[0062] In this embodiment, step S5, "obtaining the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters," specifically includes:
[0063] Based on the sag change and tensile stress distribution of the ground wire after the lightning strike, and combined with the material properties of the ground wire, the actual energy absorbed by the ground wire under the lightning strike is calculated, and its thermal stability is evaluated accordingly.
[0064] The working process is as follows: First, sensors deployed on the grounding wire acquire sag and tension data before and after a lightning strike, calculating the change in sag and the alteration of tensile stress distribution. Second, based on the grounding wire's material properties (such as elastic modulus, coefficient of linear expansion, specific heat capacity, density, and resistivity), a mechanical-thermal coupling model of the grounding wire is established. Then, this model is used to inversely calculate the energy absorbed by the grounding wire during the lightning strike, which is equal to the heat corresponding to the temperature rise caused by the Joule heating effect of the lightning current. Finally, by comparing the actual absorbed energy with the grounding wire's heat capacity threshold, the actual thermal stability of the grounding wire can be quantitatively assessed. This implementation combines macroscopic operating characteristic parameters (sag, tension) with microscopic material properties, achieving a physical inversion from operating data to lightning resistance performance indicators, avoiding complex electromagnetic transient simulations, and demonstrating strong engineering practicality.
[0065] In this embodiment, the preset threshold is dynamically adjusted based on the importance level of the line and the service life of the ground wire. Specifically, for lines bearing important loads (such as inter-regional interconnection lines and power plant transmission lines) or located in harsh environments (such as areas with strong lightning strikes or heavy pollution), their importance level is higher, and a smaller deviation threshold should be set to ensure early detection of lightning resistance degradation and reduce the risk of lightning-induced tripping. For general lines, the threshold can be appropriately relaxed to avoid unnecessary maintenance investment. Meanwhile, as the service life of the ground wire increases, material aging, corrosion, and fatigue damage will gradually accumulate, and the natural decline in lightning resistance is a normal phenomenon. Therefore, the threshold should be appropriately increased with the increase in service life to distinguish between normal aging and abnormal degradation. Through this dynamic adjustment mechanism, this method can adapt to the actual operation and maintenance needs and risk tolerance of different lines, avoiding misjudgments or omissions caused by a "one-size-fits-all" judgment standard, and improving the applicability and economy of the method.
[0066] This implementation adds step S7 to form a complete closed-loop operation and maintenance decision-making process:
[0067] Step S7: If step S6 determines that the lightning protection performance has deteriorated, then an early warning message is generated and a corresponding operation and maintenance strategy is recommended. The operation and maintenance strategy includes adjusting the ground wire sag, replacing the ground wire, or installing lightning protection auxiliary devices.
[0068] The working process is as follows: When the judgment result is deterioration, the system automatically generates early warning information including the degree of deterioration, deterioration index, deterioration location, and suggested handling time limit, and pushes it to the operation and maintenance personnel through the monitoring platform. At the same time, the system intelligently recommends the optimal operation and maintenance strategy based on the specific cause and severity of the deterioration. For example, if the deterioration is mainly caused by excessive sag, it is recommended to adjust the ground wire sag (such as tightening the ground wire); if the ground wire is severely corroded, resulting in a reduced cross-section, it is recommended to replace the ground wire; if the ground wire itself has acceptable performance but the overall lightning protection level is insufficient, it is recommended to install lightning protection auxiliary devices (such as line surge arresters, coupling ground wires, or grounding resistance reduction devices). Through this implementation method, this approach not only verifies lightning resistance performance but also directly translates into executable operation and maintenance actions, realizing a complete closed loop from "discovering the problem" to "solving the problem," greatly improving the intelligence level and response efficiency of line lightning protection management.
[0069] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.
Claims
1. A method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison, characterized in that, include: Step S1: Obtain the operating characteristic parameters of the overhead ground wire to be verified at multiple historical time points. The operating characteristic parameters include at least the ground wire sag, ground wire tension, and ground wire temperature. Step S2: Based on the operating characteristic parameters of the multiple historical time points, establish a model for the evolution of the ground wire operating characteristics over time; Step S3: Obtain the instantaneous operating characteristic parameters of the overhead ground wire to be verified when the preset lightning strike event occurs, and record them as the lightning strike time parameters; Step S4: Input the lightning strike time parameter into the evolution model to predict the theoretical lightning resistance performance index of the ground wire at the lightning strike time, which is denoted as the first performance index. Step S5: Obtain the actual operating characteristic parameters of the ground wire under the same working conditions after the lightning strike event, and invert the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters, which is recorded as the second performance index. Step S6: Compare the first performance index with the second performance index. If the deviation between the two exceeds a preset threshold, it is determined that the lightning resistance performance of the overhead ground wire has deteriorated; otherwise, it is determined to be normal.
2. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S1, the operating characteristic parameters also include at least one of the following: the degree of corrosion on the ground wire surface, the ground wire vibration frequency, and the amplitude.
3. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S1, the operating characteristic parameters are obtained in real time through distributed optical fiber sensors or wireless sensor networks deployed on the ground wire.
4. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S2, the evolution model is a regression model based on time series analysis or a prediction model based on machine learning.
5. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S3, the preset lightning strike event is identified and triggered by a lightning location system or a lightning counter installed on the tower.
6. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S4, the evolution model also inputs recent meteorological conditions parameters prior to the lightning strike to improve the prediction accuracy of the first performance index.
7. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S4, the theoretical lightning resistance performance index includes at least one of the following: the ground wire current shunting coefficient, the ground wire backflash lightning resistance level, and the ground wire thermal stability.
8. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S5, obtaining the actual lightning withstand performance index of the ground wire based on the actual operating characteristic parameters specifically includes: Based on the sag change and tensile stress distribution of the ground wire after the lightning strike, and combined with the material properties of the ground wire, the actual energy absorbed by the ground wire under the lightning strike is calculated, and its thermal stability is evaluated accordingly.
9. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, In step S6, the preset threshold is dynamically adjusted according to the importance level of the line and the service life of the ground wire.
10. The method for verifying the lightning withstand performance of overhead ground wires based on operational characteristic comparison according to claim 1, characterized in that, The method further includes: Step S7: If it is determined that the lightning protection performance has deteriorated, an early warning message is generated and a corresponding operation and maintenance strategy is recommended. The operation and maintenance strategy includes adjusting the ground wire sag, replacing the ground wire, or installing lightning protection auxiliary devices.