An intelligent evaluation method for lightning protection and grounding performance of power and communication shared towers

Abstract

The present application relates to the technical field of lightning protection and grounding performance detection, and specifically to an intelligent evaluation method for lightning protection and grounding performance of a power and communication shared iron tower, the method comprising: analyzing the difference in ground potential between each sampling point and each sampling point in its neighborhood and the difference in spatial position, as well as the distance between the sampling points, determining the potential distribution index, combining the difference between the current value of each sampling point at each acquisition moment and the current value distribution of the sampling point at all acquisition moments, constructing a lightning current attenuation value; clustering all sampling points, and determining a lightning protection performance evaluation coefficient based on the average distribution and discreteness of the lightning current attenuation values ​​of all sampling points in each clustering cluster, and evaluating the lightning protection and grounding performance of the iron tower to be evaluated. The present application aims to improve the reliability of lightning protection and grounding performance evaluation of power and communication shared iron towers.

Description

Technical Field

[0001] The present application relates to the technical field of lightning protection and grounding performance detection, and in particular to an intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower. Background Art

[0002] Power and communication shared towers refer to the installation of communication equipment on power poles and towers, and the attachment of communication facilities such as mobile antennas to the transmission tower body, so as to achieve resource sharing of power and communication infrastructure. Power and communication shared towers are widely distributed and have high building heights, making them extremely vulnerable to lightning damage. Different power and communication equipment are distributed in the steel components of the shared towers. When the shared tower is struck by lightning, the lightning current flows along the steel components and lightning conductors of the tower into the ground grid to avoid damage to the equipment, so as to ensure the safe operation of the shared tower.

[0003] The supporting structure of the power and communication shared tower is relatively complex, and there are different sizes of capacitance and inductance between different steel components. When the lightning strike point changes, the distribution of lightning current is affected by the capacitance and inductance at different positions in the tower. At present, the industry uses calculation software simulation methods to simulate the distribution of lightning current and potential on the tower body, ground grid and antenna cable when the power and communication shared tower is struck by lightning at a fixed position, thereby realizing the evaluation of the lightning protection and grounding performance of the shared tower. However, the differences in the distribution of lightning current and potential on the shared tower caused by different lightning strike points are not considered, and the calculation accuracy of the degree of influence of lightning strikes on power and communication equipment is insufficient, which leads to a decrease in the reliability of the evaluation of the lightning protection and grounding performance of the power and communication shared tower. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides an intelligent evaluation method for the lightning protection and grounding performance of a power and communication shared tower to solve the existing problems.

[0005] The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower in this application adopts the following technical solution:

[0006] An embodiment of the present application provides a method for intelligently evaluating lightning protection and grounding performance of a power and communication shared iron tower, the method comprising the following steps:

[0007] The power and communication shared tower is recorded as the tower, and multiple sampling points are set on each component of the tower to be evaluated. For the tower body in the component, each preset number of sampling points attacked by lightning are combined into a lightning strike vector, and the current value and ground potential of all sampling points on each component under each lightning strike vector at different collection times are obtained;

[0008] Analyze the difference in ground potential and spatial position between each sampling point and each sampling point in its neighborhood to determine the relative position vector of each sampling point at each acquisition time; based on the difference in ground potential between each sampling point and each sampling point in its neighborhood, the similarity in the relative position vector, and the distance between the sampling points, determine the potential distribution index of each sampling point at each acquisition time;

[0009] For each component under each lightning strike vector, based on the difference between the current value of each sampling point at each acquisition moment and the current value distribution of the sampling point at all acquisition moments, and combined with the potential distribution index, a lightning current attenuation value of each sampling point is constructed;

[0010] For each lightning strike vector, based on the distance between different sampling points and the difference in lightning current attenuation values, the attenuation characteristic distance between different sampling points on any component is determined, so as to cluster all sampling points and obtain all clusters of any component. Based on the average distribution and discreteness of the lightning current attenuation values ​​of all sampling points in each cluster, the lightning protection performance evaluation coefficient of any component under each lightning strike vector is determined.

[0011] The lightning protection performance evaluation coefficient of any component under all lightning strike vectors is iterated multiple times to obtain the minimum lightning protection performance evaluation coefficient of any component, and the lightning protection and grounding performance of the tower to be evaluated is evaluated.

[0012] Preferably, the method for determining the relative position vector of each sampling point at each acquisition moment is:

[0013] For each component under each lightning stroke vector, at the acquisition time n, the difference between the ground potential of the mth sampling point in the neighborhood of the sampling point k and the ground potential of the sampling point k is taken as the potential difference of the mth sampling point;

[0014] The spatial position coordinates of each sampling point are obtained, and the vector composed of the difference between the spatial position coordinates of the mth sampling point in the neighborhood of sampling point k and the corresponding elements of the spatial position coordinates of sampling point k is used as the relative position vector of the mth sampling point. All sampling points are traversed to obtain the relative position vector of each sampling point at each acquisition time.

[0015] Preferably, the method for determining the potential distribution index of each sampling point at each acquisition time is:

[0016] For each component under each lightning strike vector, take the absolute value of the potential difference of all sampling points in the neighborhood of each sampling point at each acquisition time, take the sampling point corresponding to the maximum value among all absolute values ​​as the feature point of each sampling point at each acquisition time, and calculate the similarity of the relative position vector between each sampling point and its feature point at each acquisition time;

[0017] Calculate the distance between each sampling point and each sampling point in its neighborhood at each acquisition time;

[0018] The product of the potential difference of each sampling point in the neighborhood of each sampling point at each acquisition time and the similarity is calculated, and the ratio of the product to the distance is used as the potential distribution index of each sampling point at each acquisition time.

[0019] Preferably, the expression of the lightning current attenuation value of each sampling point is: ; Indicates the lightning current attenuation value of the kth sampling point; Represents the maximum value of the current value of all sampling moments at the kth sampling point; Indicates the current value of sampling point k at acquisition time n; Represents the potential distribution index of the kth sampling point at the acquisition time n; Indicates the number of all acquisition moments; Represents an exponential function with a natural constant as base.

[0020] Preferably, the expression of the attenuation characteristic distance between different sampling points on any component is: ; In the formula, represents the attenuation characteristic distance between sampling point i and sampling point j on the mth block component; represents the distance between sampling point i and sampling point j on the mth block component; , They respectively represent the lightning current attenuation values ​​of sampling point i and sampling point j in the mth block component.

[0021] Preferably, obtaining all clusters of any component includes:

[0022] Under each lightning stroke vector, all sampling points of any component are used as the input of the clustering algorithm, in which the attenuation characteristic distance is set as the clustering distance between different samples, and all cluster clusters of any component are output.

[0023] Preferably, the method for determining the lightning protection performance evaluation coefficient of any component under each lightning strike vector is:

[0024] For any component under each lightning strike vector, the mean and standard deviation of the lightning current attenuation values ​​of all sampling points in each cluster are calculated respectively, and the ratio of the mean and the standard deviation is calculated. The cumulative sum of the ratios of all clusters is used as the lightning protection performance evaluation coefficient of any component under each lightning strike vector.

[0025] Preferably, obtaining the minimum lightning protection performance evaluation coefficient of any component includes:

[0026] For any component, a preset number of lightning strike vectors are used as the initial population of the whale optimization algorithm, wherein the lightning protection performance evaluation coefficients of all lightning strike vectors are set as the fitness of the whale optimization algorithm, the initial convergence factor is set to a preset value, and the lightning protection evaluation coefficients of all lightning strike vectors after the first iterative update are output to determine the convergence factor of any component in the next iteration;

[0027] The lightning protection evaluation coefficient of all lightning strike vectors after the first iteration is used as the fitness of the whale optimization algorithm in the next iteration. It is iterated in combination with the convergence factor of the next iteration until the preset maximum number of iterations is reached. The lightning protection performance evaluation coefficient of all lightning strike vectors after the iteration is output, and the minimum value is used as the minimum lightning protection performance evaluation coefficient of the corresponding component.

[0028] Preferably, the method for determining the convergence factor of any component in the next iteration is:

[0029] Convergence factor of component m at iteration v The expression is: ; represents the convergence factor of component m at the v-1th iteration; represents the lightning protection performance evaluation coefficient of component m under the w-th lightning strike vector after the v-1th iteration update; represents the minimum value of the lightning protection performance evaluation coefficient of component m under all lightning strike vectors after the v-1th iteration update; W represents the value of the preset number; norm() represents the normalization function; where, Represents the initial convergence factor of component m, which is a preset value.

[0030] Preferably, the step of evaluating the lightning protection and grounding performance of the tower to be evaluated includes:

[0031] For multiple iron towers with qualified lightning protection and grounding performance, the minimum lightning protection performance evaluation coefficients of all components of each iron tower with qualified lightning protection and grounding performance are obtained according to the method for obtaining the minimum lightning protection performance evaluation coefficient of any component on the iron tower to be evaluated, and the minimum value of all minimum lightning protection performance evaluation coefficients of each component is used as the evaluation coefficient threshold of each component;

[0032] If the minimum lightning protection performance of all components of the tower to be evaluated is greater than their corresponding evaluation coefficient thresholds, the lightning protection and grounding performance of the tower to be evaluated is qualified; otherwise, the lightning protection and grounding performance of the tower to be evaluated is unqualified.

[0033] This application has at least the following beneficial effects:

[0034] This application constructs a potential distribution index by analyzing the current difference and ground potential difference between the sampling point and the sampling points in its neighborhood, as well as the spatial position difference, which reflects the complexity of the tower support structure and electrical connection, as well as the influence of capacitance and inductance on lightning current discharge, and helps to more accurately evaluate the lightning current discharge capacity at different locations, thereby improving the accuracy of lightning protection and grounding performance evaluation; further, by analyzing the current value distribution of the sampling points and combining the potential distribution index, a lightning current attenuation value is constructed, which reflects the discharge performance of the tower at different locations when struck by lightning, thereby more accurately evaluating the lightning protection and grounding performance of the tower; further, by analyzing the difference in lightning current attenuation values ​​between different sampling points, and combining the distribution and discreteness of lightning current attenuation values ​​of the sampling point and its surrounding sampling points, a lightning protection performance evaluation coefficient is constructed, which can increase the proportion of local areas of the tower that are severely affected by lightning strikes when evaluating the lightning protection and grounding performance, thereby more accurately evaluating the lightning protection and grounding performance of the tower. This application analyzes the differences in lightning current and potential distribution on the tower, and combines the whale optimization algorithm to iteratively optimize the lightning protection grounding performance, thereby improving the reliability of the lightning protection grounding performance evaluation of the power and communication shared tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A flowchart of a method for intelligently evaluating lightning protection and grounding performance of a power and communication shared tower provided in one embodiment of the present application;

[0037] Figure 2 A structural diagram of a power and communication sharing tower provided in one embodiment of the present application;

[0038] Figure 3 A flowchart of the iterative process of lightning protection performance evaluation coefficients provided for one embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, describes in detail the specific implementation method, structure, features and effects of an intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower proposed in the present application. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0040] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0041] The specific scheme of the intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower provided by the present application is described in detail below with reference to the accompanying drawings.

[0042] An embodiment of the present application provides an intelligent evaluation method for lightning protection and grounding performance of a power and communication shared iron tower. Specifically, the following intelligent evaluation method for lightning protection and grounding performance of a power and communication shared iron tower is provided. Figure 1 , the method comprises the following steps:

[0043] Step S1: The power and communication shared tower is recorded as the tower, and multiple sampling points are set on each component of the tower to be evaluated. For the tower body in the component, each preset number of sampling points attacked by lightning are combined into a lightning strike vector, and the current values ​​and ground potentials of all sampling points on each component under each lightning strike vector at different collection times are obtained.

[0044] The structure diagram of the power and communication shared tower is as follows: Figure 2 As shown, serial number 1 represents the tower body, serial number 2 represents the communication room, serial number 3 represents the grounding network, serial number 4 represents the antenna cable, serial number 5 represents the mobile communication antenna, serial number 6 represents the insulating bracket, the mobile communication antenna is connected to the tower body with an insulating bracket, the mobile communication base station room is located under the tower body, the tower body and the indoor grounding wires of the communication base station room are connected to the grounding network together, and the lightning current is discharged along the grounding network.

[0045] According to the corresponding engineering parameters of the power and communication shared tower, the shared tower grounding model is established using the CDEGS grounding grid calculation software. The specific process of establishing the model is a technology well known to those skilled in the art and will not be repeated here. In this embodiment, the lightning current model uses the double exponential waveform in the IEC61312 standard, specifically:

[0046]

[0047] in, represents the current value of the lightning current at time t; A represents the peak value of the lightning current, which is 42000 in this embodiment; exp() represents an exponential function with a natural constant as the base; and They represent the wavefront attenuation coefficient and the waveback attenuation coefficient respectively, and in this embodiment, the values ​​are 2049.38 and 563758.3.

[0048] For ease of description, the following content refers to the power and communication shared iron tower as simply the iron tower, and all components on the iron tower in this embodiment include: the iron tower body, the grounding wire of the communication room, the grounding copper material and the antenna cable. One of the endpoints at the two ends of the bottom where the iron tower body intersects with the ground is used as the starting point, and the position at every distance d is used as a new sampling point, and sampling points are set on all steel materials of the iron tower body. At the same time, sampling points are set at every distance d on the grounding wire of the communication room, the grounding copper material and the antenna cable in the same way. In this way, the process of setting sampling points on all components of the iron tower is completed.

[0049] It should be noted that the value of the distance d is artificially set. In this embodiment, the value of the distance d is 0.1 m. The implementer can also set the distance interval d between the sampling points according to the specific situation. This embodiment does not impose any special restrictions.

[0050] Considering the situation where lightning strikes different positions of the tower body, the number of lightning strike points is set to L, and in this embodiment, L is 3. For the tower body in the component, each preset number of sampling points attacked by lightning is used to form a lightning strike vector. According to the established lightning current model and tower grounding model, the current value and ground potential of all sampling points on each component under each lightning strike vector at different collection times during the lightning day are obtained through the CDEGS grounding network calculation software.

[0051] Among them, the moment of lightning strike is taken as the initial moment, and the current value and ground potential output by the CDEGS grounding grid calculation software at the sampling point are collected every T moments, and the current value and ground potential at N collection moments are collected continuously.

[0052] It should be noted that the values ​​of the sampling interval T and all the acquisition times N are manually set. In this embodiment, the value of the sampling interval T is 0.1 microseconds and the value of N is 50. The implementer can also set them according to the specific situation. This embodiment does not impose any special restrictions.

[0053] It should be understood that when lightning strikes different positions on the tower, the current changes on the same component of the tower are also different. Therefore, in order to facilitate analysis and control the lightning strike intensity as much as possible, in this embodiment, every three lightning strike points on the tower are combined into a lightning strike vector, and the current and ground potential at each sampling point on any component under each lightning strike vector are analyzed.

[0054] For ease of understanding, an example is given below. Three sampling points on the tower body that are attacked by lightning are randomly selected. These three sampling points are marked as a, b, and c. When a, b, and c are attacked by lightning, the current and ground potential at all sampling points on each component of the tower are obtained at different acquisition times since the start of the lightning attack; then three more points are selected and the same operation is repeated to obtain the current value and ground potential at all sampling points on any component under each lightning strike vector at different acquisition times. Among them, the current value and ground potential of each sampling point on each component of the tower at different acquisition times when different lightning strike points are attacked by lightning can be obtained through the CDEGS grounding network calculation software. The CDEGS grounding network calculation software is a well-known content, and the specific process of using it to obtain the current value and ground potential will not be repeated.

[0055] Step S2: Analyze the difference in ground potential and spatial position between each sampling point and each sampling point in its neighborhood to determine the relative position vector of each sampling point at each acquisition time. Based on the difference in ground potential between each sampling point and each sampling point in its neighborhood, the similarity in the relative position vector, and the distance between the sampling points, determine the potential distribution index of each sampling point at each acquisition time.

[0056] The tower is tall and vulnerable to lightning damage. The formation of lightning discharge channels is highly random, which means that lightning discharges usually do not strike at one point. The simultaneous discharge of multiple lightning strike points causes large lightning currents to be distributed throughout the tower, and the lightning currents enter the ground grid through the steel components and lightning conductors of the tower to avoid equipment damage. Therefore, it is necessary to evaluate the lightning protection and grounding performance of the tower when it is struck by lightning at different lightning strike points to ensure the subsequent safe operation of the tower. In addition, due to the complex supporting structure of different parts of the tower, there are capacitors and inductors of different sizes in various parts of the tower, which hinder the discharge of lightning currents, and the hindering effect varies under the action of different lightning strike points.

[0057] Therefore, considering that the discharge of lightning current is affected by capacitance and inductance, it is necessary to evaluate the lightning protection and grounding performance of the tower body, ground grid, indoor grounding wire of the communication room and antenna cable respectively. By analyzing the difference in ground potential between the sampling point and its surrounding sampling points on the same component and the difference in spatial position, the potential distribution index of each sampling point at each acquisition time is determined to ensure that the lightning protection and grounding structure of the tower can simultaneously meet the normal operation of power and communication equipment at different locations. Specifically:

[0058] (1) Divide a neighborhood with each sampling point as the center, wherein the neighborhood radius is set to D. The value of the neighborhood radius D is artificially set. In this embodiment, the value of the neighborhood radius D is 1m. The implementer can also set it by himself according to the specific situation. This embodiment does not impose any special restrictions.

[0059] (2) Further, for each component under each lightning stroke vector, at the acquisition time n, the difference between the ground potential of the mth sampling point in the neighborhood of the sampling point k and the ground potential of the sampling point k is taken as the potential difference of the mth sampling point;

[0060] The spatial position coordinates of each sampling point are obtained, and the vector composed of the difference between the spatial position coordinates of the mth sampling point in the neighborhood of sampling point k and the corresponding elements of the spatial position coordinates of sampling point k is used as the relative position vector of the mth sampling point. All sampling points are traversed to obtain the relative position vector of each sampling point at each acquisition time.

[0061] (3) Further, for each component under each lightning strike vector, the absolute value of the potential difference of all sampling points in the neighborhood of each sampling point at each acquisition time is taken, and the sampling point corresponding to the maximum value among all absolute values ​​is taken as the feature point of each sampling point at each acquisition time, and the similarity of the relative position vector between each sampling point and its feature point at each acquisition time is calculated;

[0062] The distance between each sampling point and each sampling point in its neighborhood at each acquisition moment is calculated; the product of the potential difference and the similarity of each sampling point in the neighborhood of each sampling point at each acquisition moment is calculated, and the ratio of the product to the distance is used as the potential distribution index of each sampling point at each acquisition moment.

[0063] It should be noted that there are many methods for measuring the similarity between vectors. In this embodiment, the cosine similarity between the relative position vectors between each sampling point and its feature point is calculated to measure the similarity between the relative position vectors between the sampling point and the feature point. The implementer may also use other methods for measuring the similarity between vectors, such as the inverse of the Euclidean distance. This embodiment does not impose any special restrictions on the selection of methods for measuring the similarity between vectors.

[0064] The steps for calculating the cosine similarity are well-known techniques, and the specific calculation process will not be described in detail.

[0065] Furthermore, according to the potential distribution index of each sampling point at each acquisition time, it can be understood that the more sampling points there are in the neighborhood, the more complex the surrounding support structure and electrical connection structure are, the greater the influence of capacitance and inductance on the discharge of lightning current, and the greater the calculated potential distribution index. The position of the sampling point with the largest potential difference in the neighborhood reflects the direction of the largest change in the potential gradient of the central sampling point. When the distance between the sampling point and the sampling point located at the center of its neighborhood is closer, the potential difference is larger and closer to the direction of the potential gradient change, the electric field intensity generated by the potential distribution at the sampling point in the center of the neighborhood in the direction of the maximum potential gradient is greater, the breakdown risk caused to the surrounding equipment is greater, and the larger the capacitance value formed is, the greater the influence on the discharge performance of the tower is, so the calculated potential distribution index is greater; conversely, if the distance between the sampling point and the sampling point in the center of its neighborhood is greater, the similarity of the relative position vector between the sampling point and the sampling point in the center of its neighborhood is smaller, and the potential difference of the sampling point is smaller, then the calculated potential distribution index is smaller, indicating that the breakdown risk caused by lightning to the surrounding equipment is smaller.

[0066] Step S3: for each component under each lightning strike vector, construct the lightning current attenuation value of each sampling point according to the difference between the current value of each sampling point at each acquisition moment and the current value distribution of the sampling point at all acquisition moments, and in combination with the potential distribution index.

[0067] When the tower is struck by lightning at different positions, there are large differences in the charging and discharging states of the inductance and capacitance at different positions. In severe cases, this will increase the time that the lightning current energy is stored in the tower, causing the lightning current to decay more slowly and reducing the lightning protection and grounding performance of the tower.

[0068] Therefore, by analyzing the difference between the current value of each sampling point at each collection time and the current value distribution of the sampling point at all collection times, and combining the potential distribution index, the lightning attenuation current value of each sampling point is constructed, thereby reflecting the discharge performance of all sampling points on the tower when the tower is struck by lightning, specifically:

[0069] For each component under each lightning strike vector, the lightning current attenuation value of the kth sampling point The expression is: ; Indicates the lightning current attenuation value of the kth sampling point; Represents the maximum value of the current value of all sampling moments at the kth sampling point; Indicates the current value of sampling point k at acquisition time n; Represents the potential distribution index of the kth sampling point at the acquisition time n; Indicates the number of all acquisition moments; Represents an exponential function with a natural constant as base.

[0070] According to the lightning current attenuation value of each sampling point, it can be understood that the potential distribution index of the sampling point reflects the risk of damage to the tower caused by the potential difference formed by the lightning strike at the sampling point. The larger the potential distribution index, the greater the risk of damage to the tower caused by the same lightning current. At the same time, the larger the potential distribution index, the greater the obstacle to the discharge of lightning current by the surrounding inductance and capacitance. Therefore, the calculated lightning current attenuation value is smaller. And the maximum value of the current value of the sampling point at all acquisition times reflects the moment when the location is most affected by the lightning strike. The larger the maximum current value formed by the lightning strike, the longer the time required for the subsequent current value to be discharged, and the smaller the calculated lightning current attenuation value; in addition, the ratio of the current value to the maximum current value at all acquisition times reflects the area of ​​the lightning current waveform at the sampling point. The smaller the ratio of the current value to the maximum current value at all acquisition times, the slower the current value decays. The slower the ratio of the current value to the maximum current value decreases, the larger the waveform area, and the smaller the calculated lightning current attenuation value;

[0071] On the contrary, if the potential distribution index is smaller, the maximum value of the current value at all sampling moments at the sampling point is smaller, and the ratio of the current value at all sampling moments to the maximum current value is larger, then the lightning current attenuation value is larger, indicating that the lightning current decays faster and the risk of damage to the tower is smaller.

[0072] Step S4: For each lightning strike vector, based on the distance between different sampling points and the difference in lightning current attenuation values, determine the attenuation characteristic distance between different sampling points on any component, cluster all sampling points, and obtain all clustering clusters of any component. Based on the average distribution and discreteness of the lightning current attenuation values ​​of all sampling points in each clustering cluster, determine the lightning protection performance evaluation coefficient of any component under each lightning strike vector.

[0073] S401: For each lightning stroke vector, based on the distance between different sampling points and the difference in lightning current attenuation values, determine the attenuation characteristic distance between different sampling points on any component, so as to cluster all sampling points and obtain all clusters of any component.

[0074] Considering the different complexity of the supporting structure and electrical connection structure at different positions of the tower, there are differences in the discharge performance of lightning current, and different lightning strike positions exacerbate the expansion of this difference. Therefore, by analyzing the lightning current attenuation value and position distribution of the sampling points, the sampling points on different components of the tower are clustered, specifically:

[0075] First, according to the lightning current attenuation value, the attenuation value characteristic distance between different sampling points is calculated, specifically:

[0076] The expression of the attenuation characteristic distance between different sampling points on any component is: ; In the formula, represents the attenuation characteristic distance between sampling point i and sampling point j on the mth block component; represents the distance between sampling point i and sampling point j on the mth block component; , They respectively represent the lightning current attenuation values ​​of sampling point i and sampling point j in the mth block component.

[0077] Furthermore, under each lightning strike vector, all sampling points of any component are used as inputs of the clustering algorithm, wherein the attenuation characteristic distance is set as the clustering distance between different samples, and all clusters of any component are output.

[0078] It should be noted that there are many commonly used clustering algorithms. In this embodiment, the DBSCAN density clustering algorithm is used to cluster the sampling points of different parts of the tower. The implementer can also use other clustering methods such as the k-means clustering algorithm. This embodiment does not impose any special restrictions on the selection of clustering algorithms.

[0079] Among them, the DBSCAN density clustering algorithm is a well-known technology, and its specific clustering principle is not repeated here.

[0080] In particular, the outlier points after clustering are treated as clusters containing only one sampling point.

[0081] S402: Determine the lightning protection performance evaluation coefficient of any component under each lightning strike vector based on the average distribution and discreteness of the lightning current attenuation values ​​of all sampling points in each cluster.

[0082] Due to the poor lightning current discharge performance at some complex structural locations of the tower, the risk of damage to the equipment near this location is relatively high after being struck by lightning at different locations. In order to increase the weight of the local areas of the tower that are severely affected by lightning strikes when evaluating the lightning protection and grounding performance, the lightning protection performance evaluation coefficient is calculated based on the obtained clusters of different sampling points and the lightning current attenuation values, specifically:

[0083] For any component under each lightning strike vector, the mean and standard deviation of the lightning current attenuation values ​​of all sampling points in each cluster are calculated respectively, and the ratio of the mean and the standard deviation is calculated. The cumulative sum of the ratios of all clusters is used as the lightning protection performance evaluation coefficient of any component under each lightning strike vector.

[0084] According to the lightning protection performance evaluation coefficient of any component under each lightning strike vector, it can be understood that, on the one hand, the larger the mean value of the lightning current attenuation value of the sampling points in the cluster, the better the lightning current discharge performance at the location of the cluster, and the larger the lightning protection performance evaluation coefficient. On the other hand, the smaller the standard deviation of the lightning current attenuation value of the sampling points in the cluster, the more consistent the lightning protection performance distribution of the sampling points at the corresponding positions, and the larger the calculated lightning protection performance evaluation coefficient; on the contrary, if the mean value of the lightning current attenuation value of the sampling points in the cluster is smaller and the standard deviation is larger, the lightning protection performance evaluation coefficient is smaller, indicating that the lightning current discharge performance at the location of the sampling points in the cluster is worse.

[0085] Step S5: Iterate the lightning protection performance evaluation coefficient of any component under all lightning strike vectors for multiple times to obtain the minimum lightning protection performance evaluation coefficient of any component, and evaluate the lightning protection and grounding performance of the tower to be evaluated.

[0086] There are differences in the lightning protection and grounding performance of different components of the tower when struck by lightning at the same position. At the same time, the lightning protection and grounding performance of the same part after being struck by lightning at different positions is also different. In order to accurately evaluate the lightning protection and grounding performance of each component of the tower and ensure that it can still operate normally when it is most seriously affected by lightning, the whale optimization algorithm is used to obtain the minimum lightning protection performance evaluation coefficient of different components of the tower, specifically:

[0087] For any component, a preset number of lightning strike vectors are used as the initial population of the whale optimization algorithm, wherein the lightning protection performance evaluation coefficients of all lightning strike vectors are set as the fitness of the whale optimization algorithm, the initial convergence factor is set to a preset value, and the lightning protection evaluation coefficients of all lightning strike vectors after the first iterative update are output to determine the convergence factor of any component in the next iteration;

[0088] The lightning protection evaluation coefficient of all lightning strike vectors after the first iteration is used as the fitness of the whale optimization algorithm in the next iteration. It is iterated in combination with the convergence factor of the next iteration until the preset maximum number of iterations is reached. The lightning protection performance evaluation coefficient of all lightning strike vectors after the iteration is output, and the minimum value is used as the minimum lightning protection performance evaluation coefficient of the corresponding component.

[0089] It should be noted that the values ​​of the preset number and the preset maximum number of iterations are both manually set. In this embodiment, the value of the preset number is 30, and the value of the preset maximum number of iterations is 30. The implementer can also set them according to the specific situation. This embodiment does not impose any special restrictions.

[0090] Among them, the convergence factor of any component at the next iteration, that is, the convergence factor of any component at each iteration, is determined as follows:

[0091] Convergence factor of component m at iteration v The expression is: ; represents the convergence factor of component m at the v-1th iteration; It represents the lightning protection performance evaluation coefficient of component m under the w-th lightning strike vector after the v-1th iteration update; represents the minimum value of the lightning protection performance evaluation coefficient of component m under all lightning strike vectors after the v-1th iteration update; W represents the value of the preset number; norm() represents the normalization function; where, Represents the initial convergence factor of component m, which is a preset value.

[0092] Due to the complex structure of the tower, the influence of the change of the lightning protection performance evaluation coefficient on the position of the lightning strike point is relatively random. Therefore, in order to avoid the optimization process falling into the local optimum, at the beginning of the iteration, the ratio of the lightning protection performance evaluation coefficient of the lightning strike vector in the corresponding iteration to the minimum lightning protection performance evaluation coefficient in the iteration is used as the weight to reduce the rate of decrease of the convergence factor and expand the optimization range in the initial iteration. At the same time, at the end of the iteration, the impact of adjacent lightning strike points on the tower is close, at this time, the rate of decrease of the convergence factor is increased to improve the accuracy of the optimization.

[0093] It should be noted that the value of the initial convergence factor is a preset value, which is set manually. The value of the initial convergence factor of all components is 2, and the implementer can also set it according to the specific situation. This embodiment does not impose any special restrictions.

[0094] Preferably, the lightning protection performance evaluation coefficient iteration process flow chart provided in this embodiment is as follows: Figure 3 shown.

[0095] Further, according to the above steps S1-S5, Q iron towers with qualified lightning protection and grounding performance are obtained, and according to the method for obtaining the minimum lightning protection performance evaluation coefficient of any component on the iron tower to be evaluated, the minimum lightning protection performance evaluation coefficient of all components of each iron tower with qualified lightning protection and grounding performance is obtained, and the minimum value of all minimum lightning protection performance evaluation coefficients of each component is used as the evaluation coefficient threshold of each component;

[0096] If the minimum lightning protection performance of all components of the tower to be evaluated is greater than their corresponding evaluation coefficient thresholds, the lightning protection and grounding performance of the tower to be evaluated is qualified; otherwise, the lightning protection and grounding performance of the tower to be evaluated is unqualified.

[0097] Among them, the value of Q is set manually. In this embodiment, the minimum lightning protection performance evaluation coefficient of all components on 500 towers with qualified lightning protection and grounding performance is obtained. The implementer can also set the Q value according to the specific situation. This embodiment does not impose any special restrictions.

[0098] At this point, this embodiment analyzes the distribution differences of lightning current and potential at different sampling points to obtain the lightning protection and grounding performance when different components are most affected by lightning strikes. While enhancing the mutual applicability of the evaluation of different components of the shared tower, it also improves the reliability of the lightning protection and grounding performance evaluation of the power and communication shared tower.

[0099] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0100] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0101] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Modifications to the technical solutions recorded in the aforementioned embodiments, or equivalent replacement of some of the technical features therein, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An intelligent evaluation method for lightning protection and grounding performance of power and communication shared towers, characterized in that: The method comprises the following steps: The power and communication shared tower is recorded as the tower, and multiple sampling points are set on each component of the tower to be evaluated. For the tower body in the component, each preset number of sampling points attacked by lightning are combined into a lightning strike vector, and the current value and ground potential of all sampling points on each component under each lightning strike vector at different collection times are obtained; Analyze the difference in ground potential and spatial position between each sampling point and each sampling point in its neighborhood to determine the relative position vector of each sampling point at each acquisition time; for each component under each lightning strike vector, take the absolute value of the potential difference of all sampling points in the neighborhood of each sampling point at each acquisition time, record the sampling point corresponding to the maximum value among all absolute values ​​as a feature point, and calculate the similarity of the relative position vector between each sampling point and its feature point at each acquisition time; take the product of the potential difference of each sampling point in the neighborhood of each sampling point at each acquisition time and the similarity and the ratio of the distance between each sampling point at each acquisition time and each sampling point in its neighborhood as the potential distribution index of each sampling point at each acquisition time; Based on the difference in ground potential between each sampling point and each sampling point in its neighborhood, the similarity in relative position vector, and the distance between the sampling points, the potential distribution index of each sampling point at each acquisition time is determined; For each component under each lightning strike vector, based on the difference between the current value of each sampling point at each acquisition moment and the current value distribution of the sampling point at all acquisition moments, and combined with the potential distribution index, a lightning current attenuation value of each sampling point is constructed; For each lightning strike vector, based on the distance between different sampling points and the difference in lightning current attenuation values, the attenuation characteristic distance between different sampling points on any component is determined, so as to cluster all sampling points and obtain all clusters of any component. Based on the average distribution and discreteness of the lightning current attenuation values ​​of all sampling points in each cluster, the lightning protection performance evaluation coefficient of any component under each lightning strike vector is determined. Perform multiple iterations on the lightning protection performance evaluation coefficient of any component under all lightning strike vectors to obtain the minimum lightning protection performance evaluation coefficient of any component, and evaluate the lightning protection and grounding performance of the tower to be evaluated; The expression of the lightning current attenuation value of each sampling point is: ; Indicates the lightning current attenuation value of the kth sampling point; Represents the maximum value of the current value of all sampling moments at the kth sampling point; Indicates the current value of sampling point k at acquisition time n; Represents the potential distribution index of the kth sampling point at the acquisition time n; Indicates the number of all acquisition moments; represents an exponential function with a natural constant as base; The expression of the attenuation characteristic distance between different sampling points on any component is: ; In the formula, represents the attenuation characteristic distance between sampling point i and sampling point j on the mth block component; represents the distance between sampling point i and sampling point j on the mth block component; , They respectively represent the lightning current attenuation values ​​of sampling point i and sampling point j in the mth block component.

2. The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower according to claim 1, characterized in that: The method for determining the relative position vector of each sampling point at each acquisition moment is: For each component under each lightning stroke vector, at the acquisition time n, the difference between the ground potential of the mth sampling point in the neighborhood of the sampling point k and the ground potential of the sampling point k is taken as the potential difference of the mth sampling point; The spatial position coordinates of each sampling point are obtained, and the vector composed of the difference between the spatial position coordinates of the mth sampling point in the neighborhood of sampling point k and the corresponding elements of the spatial position coordinates of sampling point k is used as the relative position vector of the mth sampling point. All sampling points are traversed to obtain the relative position vector of each sampling point at each acquisition time.

3. The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower according to claim 1, characterized in that: The method obtains all clusters of any component, including: Under each lightning stroke vector, all sampling points of any component are used as the input of the clustering algorithm, in which the attenuation characteristic distance is set as the clustering distance between different samples, and all cluster clusters of any component are output.

4. The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower according to claim 1, characterized in that: The method for determining the lightning protection performance evaluation coefficient of any component under each lightning strike vector is: For any component under each lightning strike vector, the mean and standard deviation of the lightning current attenuation values ​​of all sampling points in each cluster are calculated respectively, and the ratio of the mean and the standard deviation is calculated. The cumulative sum of the ratios of all clusters is used as the lightning protection performance evaluation coefficient of any component under each lightning strike vector.

5. The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower according to claim 1, characterized in that: The minimum lightning protection performance evaluation coefficient of any component is obtained, including: For any component, a preset number of lightning strike vectors are used as the initial population of the whale optimization algorithm, wherein the lightning protection performance evaluation coefficients of all lightning strike vectors are set as the fitness of the whale optimization algorithm, the initial convergence factor is set to a preset value, and the lightning protection evaluation coefficients of all lightning strike vectors after the first iterative update are output to determine the convergence factor of any component in the next iteration; The lightning protection evaluation coefficient of all lightning strike vectors after the first iteration is used as the fitness of the whale optimization algorithm in the next iteration. It is iterated in combination with the convergence factor of the next iteration until the preset maximum number of iterations is reached. The lightning protection performance evaluation coefficient of all lightning strike vectors after the iteration is output, and the minimum value is used as the minimum lightning protection performance evaluation coefficient of the corresponding component.

6. The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower as claimed in claim 5, characterized in that: The method for determining the convergence factor of any component in the next iteration is: Convergence factor of component m at iteration v The expression is: ; represents the convergence factor of component m at the v-1th iteration; It represents the lightning protection performance evaluation coefficient of component m under the w-th lightning strike vector after the v-1th iteration update; represents the minimum value of the lightning protection performance evaluation coefficient of component m under all lightning strike vectors after the v-1th iteration update; W represents the value of the preset number; norm() represents the normalization function; where, Represents the initial convergence factor of component m, which is a preset value.

7. The intelligent evaluation method for lightning protection and grounding performance of a power and communication shared tower according to claim 1, characterized in that: The lightning protection and grounding performance of the tower to be evaluated is evaluated, including: For multiple iron towers with qualified lightning protection and grounding performance, the minimum lightning protection performance evaluation coefficients of all components of each iron tower with qualified lightning protection and grounding performance are obtained according to the method for obtaining the minimum lightning protection performance evaluation coefficient of any component on the iron tower to be evaluated, and the minimum value of all minimum lightning protection performance evaluation coefficients of each component is used as the evaluation coefficient threshold of each component; If the minimum lightning protection performance of all components of the tower to be evaluated is greater than their corresponding evaluation coefficient thresholds, the lightning protection and grounding performance of the tower to be evaluated is qualified; otherwise, the lightning protection and grounding performance of the tower to be evaluated is unqualified.

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