A lightning fault locating method and device for a multi-branch power distribution line and a storage medium

Abstract

This invention relates to the field of lightning protection technology for power transmission and distribution lines, and discloses a method, device, and storage medium for locating lightning faults in multi-branch control lines. The invention analyzes the attenuation law of lightning current amplitude and the polarity relationship of lightning current on the main line based on distributed monitoring data of the multi-branch control lines to determine the lightning strike interval. Target monitoring points are determined based on the peak lightning current collected by distributed lightning current monitoring terminals within the lightning strike interval. Wavelet transform is performed on the lightning current waveform data corresponding to each target monitoring point, and the time point of the wavelet transform maxima is taken as the arrival time of the traveling wave of the lightning fault. The distance from the lightning fault point to the corresponding target monitoring point is calculated to determine the set of lightning fault points corresponding to each target monitoring point. The intersection of all determined sets of lightning fault points is calculated to eliminate false lightning fault points. This invention enables rapid and accurate location and identification of lightning faults in multi-branch control lines.

Description

Technical Field

[0001] This invention relates to the field of lightning protection technology for power transmission and distribution lines, and in particular to a method, device, and storage medium for locating lightning strike faults in multi-branch power transmission lines. Background Technology

[0002] Lightning strikes have always been a significant threat to the safe and stable operation of power systems, with 60-70% of tripping incidents on overhead transmission lines caused by lightning. Compared to overhead transmission lines, multi-branch transmission lines are more likely to experience power outages due to lightning strikes because of factors such as lower insulation levels, wider distribution, and poor tower grounding conditions.

[0003] Currently, research on lightning fault location methods for overhead transmission lines is relatively mature both domestically and internationally. However, research on lightning fault location and identification technologies for multi-branch transmission lines is scarce. Lightning fault location for overhead transmission lines mostly employs traveling wave theory. However, multi-branch transmission lines typically consist of complex multi-branch lines. After a lightning strike, these multi-branch lines generate complex traveling wave reflections, resulting in waveforms and parameters that differ significantly from those of transmission lines. Simply applying traditional traveling wave theory cannot achieve rapid and accurate fault location.

[0004] Therefore, it is necessary to provide a solution that can quickly and accurately locate and identify lightning strike faults in multi-branch power lines. Summary of the Invention

[0005] This invention provides a method, device, and storage medium for locating lightning faults in multi-branch control lines, solving the technical problem of how to quickly and accurately locate and identify lightning faults in multi-branch control lines.

[0006] The first aspect of this invention provides a method for locating lightning faults in multi-branch power lines, wherein multiple monitoring points are spaced apart on the main line of the multi-branch power line, and one monitoring point is arranged on each branch line. Each monitoring point is equipped with a distributed lightning current monitoring terminal. The method includes:

[0007] Acquire lightning current waveform data collected by each distributed lightning current monitoring terminal, analyze the lightning current amplitude attenuation law of the multi-branch power line and the polarity relationship of the lightning current on the main line based on the lightning current waveform data, and determine the lightning strike interval based on the analysis results.

[0008] Based on the peak value of the lightning current collected by the distributed lightning current monitoring terminal within the lightning strike interval, target monitoring points are selected from each monitoring point within the lightning strike interval.

[0009] Perform wavelet transform on the lightning current waveform data corresponding to each target monitoring point, take the time point when the maximum value of the wavelet transform appears as the arrival time of the lightning strike fault traveling wave, and calculate the distance from the lightning strike fault point to the corresponding target monitoring point;

[0010] According to the distance from the lightning strike fault point to the corresponding target monitoring point, determine the set of lightning strike fault points corresponding to each target monitoring point, find the intersection of all determined sets of lightning strike fault points, and use the obtained intersection result as the lightning strike fault point of the multi-branch distribution line.

[0011] According to an achievable manner of the first aspect of the present invention, the determining the lightning strike interval according to the obtained analysis result includes:

[0012] Take the interval between two adjacent monitoring points on the main line as a monitoring interval, and determine the interval type to which each monitoring interval belongs according to the number of branch lines connected to the main line section within the monitoring interval. The interval types include an interval where the main line section has no connected branch lines, an interval where the main line section is connected to one branch line, and an interval where the main line section is connected to multiple branch lines;

[0013] Calculate the average value of the lightning current amplitude attenuation rate corresponding to each interval type according to the lightning current amplitude attenuation law, calculate the difference between the lightning current amplitude attenuation rate corresponding to each monitoring interval and the average value of the lightning current amplitude attenuation rate corresponding to the interval type to which it belongs, and take the monitoring interval with a difference greater than the preset threshold as the alternative lightning strike interval;

[0014] Determine the lightning strike interval from each of the alternative lightning strike intervals according to the lightning current polarity relationship on the main line.

[0015] According to an achievable manner of the first aspect of the present invention, the screening out of target monitoring points from each monitoring point within the lightning strike interval according to the peak value of the lightning current collected by the distributed lightning current monitoring terminal within the lightning strike interval includes:

[0016] Sort the corresponding monitoring points in descending order according to the peak value of the lightning current collected by the distributed lightning current monitoring terminal within the lightning strike interval;

[0017] Select the first n monitoring points as target monitoring points, where n < N, and N is the number of monitoring points within the lightning strike interval.

[0018] According to an achievable manner of the first aspect of the present invention, the method further includes:

[0019] Determine the lightning current waveform characteristics and variation laws of the multi-branch distribution line under lightning strikes of different types through simulation analysis, and extract typical characteristics for identifying the lightning strike type according to the lightning current waveform characteristics and variation laws;

[0020] Extract the lightning current waveform features corresponding to the lightning strike interval, and compare the extracted lightning current waveform features with each of the typical features to determine the lightning strike type;

[0021] If the determined lightning strike type is induced lightning or direct lightning, determine whether a flashover has occurred on the line in the lightning strike interval, and output the corresponding line flashover determination result.

[0022] A second aspect of the present invention provides a lightning fault location device for a multi-branch power line, wherein multiple monitoring points are arranged at intervals on the main line of the multi-branch power line, and one monitoring point is arranged on each branch line. Each monitoring point is equipped with a distributed lightning current monitoring terminal. The device includes:

[0023] The lightning strike interval determination module is used to acquire lightning current waveform data collected by each distributed lightning current monitoring terminal, analyze the lightning current amplitude attenuation law of the multi-branch power line and the polarity relationship of the lightning current on the main line based on the lightning current waveform data, and determine the lightning strike interval based on the analysis results.

[0024] The target monitoring point screening module is used to screen target monitoring points from each monitoring point in the lightning strike interval based on the peak value of the lightning current collected by the distributed lightning current monitoring terminal in the lightning strike interval.

[0025] The lightning fault point distance calculation module is used to perform wavelet transform on the lightning current waveform data corresponding to each target monitoring point, take the time point when the maximum value of the wavelet transform appears as the arrival time of the traveling wave of the lightning fault, and calculate the distance from the lightning fault point to the corresponding target monitoring point.

[0026] The lightning fault location module is used to determine the set of lightning fault points corresponding to each target monitoring point based on the distance from the lightning fault point to the corresponding target monitoring point, find the intersection of all determined sets of lightning fault points, and use the obtained intersection result as the lightning fault point of the multi-branch power line.

[0027] According to one achievable method of the second aspect of the present invention, the lightning strike interval determination module includes:

[0028] The interval classification unit is used to classify the interval between two adjacent monitoring points on the main line as a monitoring interval, and to determine the interval type of each monitoring interval according to the number of branch lines connected to the main line segment within the monitoring interval. The interval type includes intervals where the main line segment has no connected branch lines, intervals where the main line segment is connected to one branch line, and intervals where the main line segment is connected to multiple branch lines.

[0029] A first interval determination unit, configured to calculate an average value of lightning current amplitude attenuation rates corresponding to each interval type according to the lightning current amplitude attenuation law, calculate a difference between the lightning current amplitude attenuation rate corresponding to each of the monitoring intervals and the average value of the lightning current amplitude attenuation rates corresponding to the interval type to which it belongs, and use the monitoring intervals with a difference greater than a preset threshold as alternative lightning strike intervals;

[0030] A second interval determination unit, configured to determine a lightning strike interval from each of the alternative lightning strike intervals according to the lightning current polarity relationship on the main line.

[0031] According to an implementable manner of the second aspect of the present invention, the target monitoring point screening module includes:

[0032] A monitoring point sorting unit, configured to sort the corresponding monitoring points in descending order of the peak lightning current collected by the distributed lightning current monitoring terminals within the lightning strike interval;

[0033] A monitoring point screening unit, configured to select the first n monitoring points as target monitoring points, where n < N, and N is the number of monitoring points within the lightning strike interval.

[0034] According to an implementable manner of the second aspect of the present invention, the device further includes:

[0035] A simulation analysis module, configured to determine the lightning current waveform characteristics and change laws of the multi-branch distribution line under lightning strikes of different types through simulation analysis, and extract typical characteristics for identifying the lightning strike type according to the lightning current waveform characteristics and change laws;

[0036] A lightning strike type determination module, configured to extract the lightning current waveform characteristics corresponding to the lightning strike interval, and compare the extracted lightning current waveform characteristics with each of the typical characteristics to determine the lightning strike type;

[0037] A line flashover judgment module, configured to judge whether the line on the lightning strike interval has a flashover when the determined lightning strike type is an induced lightning or a direct lightning strike, and output a corresponding line flashover determination result.

[0038] The third aspect of the present invention provides a multi-branch distribution line lightning fault location device, including:

[0039] A memory, configured to store instructions; wherein, the instructions are used to implement the multi-branch distribution line lightning fault location method described in any one of the above implementable manners;

[0040] A processor, configured to execute the instructions in the memory.

[0041] The fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for locating lightning strike faults in multi-line circuits as described in any of the above embodiments.

[0042] As can be seen from the above technical solutions, the present invention has the following advantages:

[0043] This invention monitors multi-branch control lines using distributed lightning current monitoring. Based on the monitored lightning current waveform data, it analyzes the attenuation law of the lightning current amplitude in the multi-branch control lines and the polarity relationship of the lightning current on the main line. Based on the analysis results, it determines the lightning strike interval. Then, based on the peak lightning current collected by the distributed lightning current monitoring terminals within the lightning strike interval, it selects target monitoring points from the monitoring points within the interval. Next, it performs wavelet transform on the lightning current waveform data corresponding to each target monitoring point, taking the time point of the wavelet transform maxima as the arrival time of the traveling wave of the lightning fault. It calculates the distance from the lightning fault point to the corresponding target monitoring point, and finally determines the set of lightning fault points corresponding to each target monitoring point based on the calculated distances. The intersection of all determined sets of lightning fault points is then calculated, and the intersection result is used as... This invention identifies lightning strike fault points in multi-branch 10kV distribution lines. It combines the attenuation law of lightning current amplitude in multi-branch distribution lines with the polarity relationship of lightning current on the main line to determine the lightning strike interval, improving the accuracy of interval determination. By selecting target monitoring points from each monitoring point within the lightning strike interval, and locating the lightning strike fault point based on the set of lightning strike fault points at the target monitoring points, efficiency is improved compared to locating the lightning strike fault point based on the set of lightning strike fault points at all monitoring points within the lightning strike interval. Finally, by finding the intersection of all determined lightning strike fault point sets, false lightning strike fault points are eliminated, further improving the accuracy of lightning strike fault point location. This enables rapid and accurate location and identification of lightning strike faults in multi-branch 10kV distribution lines, providing a foundation for quickly troubleshooting faults in multi-branch 10kV distribution networks and rapidly restoring power supply. Attached Figure Description

[0044] 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.

[0045] Figure 1 A schematic diagram of the arrangement of distributed lightning current monitoring terminals on multiple branch lines in a distributed monitoring system provided in an optional embodiment of the present invention;

[0046] Figure 2A flowchart of a method for locating lightning strike faults in multi-line substations, provided as an optional embodiment of the present invention;

[0047] Figure 3 A flowchart of a method for locating lightning strike faults in multi-line control systems, provided as another optional embodiment of the present invention;

[0048] Figure 4 This is a structural connection block diagram of a multi-branch power line lightning fault location device provided in an optional embodiment of the present invention;

[0049] Figure 5 The diagram below shows the structural connection of a multi-branch power line lightning fault location device, which is provided as an optional embodiment of the present invention.

[0050] Figure label:

[0051] 1-Lightning strike interval determination module; 2-Target monitoring point screening module; 3-Lightning strike fault point distance calculation module; 4-Lightning strike fault point location module; 5-Simulation analysis module; 6-Lightning strike type determination module; 7-Line flashover judgment module. Detailed Implementation

[0052] This invention provides a method, apparatus, and storage medium for locating lightning faults in multi-branch control lines, which addresses the technical problem of how to quickly and accurately locate and identify lightning faults in multi-branch control lines.

[0053] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0054] It should be noted that this invention is based on a distributed monitoring system. Specifically, when implementing the method and apparatus of this invention, multiple monitoring points are spaced out on the main line of the multi-branch power line requiring lightning fault location, and one monitoring point is arranged on each branch line. Each monitoring point is equipped with a distributed lightning current monitoring terminal, such as... Figure 1 As shown, M1, M2, ..., M are arranged on the main line of the multi-branch control line. w There are N1, N2, ..., N6 distributed lightning current monitoring terminals, with one distributed lightning current monitoring terminal deployed on each branch line. wThis invention uses data from distributed lightning current monitoring terminals to locate lightning strike faults in multi-line distribution systems. To ensure the effectiveness of data acquisition, the deployed distributed lightning current monitoring terminals must meet bandwidth requirements and ensure clock synchronization among all terminals.

[0055] This invention provides a method for locating lightning strike faults in multi-branch power lines.

[0056] Please see Figure 2 , Figure 2 The flowchart of a method for locating lightning strike faults in multi-branch power lines provided by an embodiment of the present invention is shown.

[0057] This invention provides a method for locating lightning strike faults in multi-branch power lines, comprising:

[0058] Step S1: Obtain the lightning current waveform data collected by each distributed lightning current monitoring terminal; analyze the lightning current amplitude attenuation law of the multi-branch power line and the polarity relationship of the lightning current on the main line based on the lightning current waveform data; and determine the lightning strike interval based on the analysis results.

[0059] In one feasible approach, determining the lightning strike zone based on the obtained analysis results includes:

[0060] The interval between two adjacent monitoring points on the main line is taken as a monitoring interval. The interval type of each monitoring interval is determined according to the number of branch lines connected to the main line segment within the monitoring interval. The interval type includes intervals where the main line segment has no connected branch lines, intervals where the main line segment is connected to one branch line, and intervals where the main line segment is connected to multiple branch lines.

[0061] Calculate the average lightning current amplitude attenuation rate corresponding to each interval type according to the lightning current amplitude attenuation law, calculate the difference between the lightning current amplitude attenuation rate corresponding to each monitoring interval and the average lightning current amplitude attenuation rate corresponding to the interval type, and select the monitoring interval with the difference greater than the preset threshold as the candidate lightning strike interval.

[0062] The lightning strike interval is determined from each of the candidate lightning strike intervals based on the polarity relationship of the lightning current on the main line.

[0063] According to the attenuation law of lightning current amplitude on multi-branch 10kV distribution lines, the attenuation rate of the lightning current peak value varies depending on the number of branches in each section of the multi-branch line. Furthermore, when a lightning strike occurs in a monitoring section, the attenuation rate of the line lightning current peak value also differs between adjacent and more distant sections. For example, in each monitoring section of the main line, when the lightning current passes through a section of the main line without connecting branches, the peak attenuation is less than 20%. However, when a lightning strike occurs in a section adjacent to a section of the main line without connecting branches, the attenuation of the lightning current amplitude in that section is 27.7%. The average attenuation rate of the line lightning current amplitude in sections of the main line connected to one branch does not exceed 40%, while when a lightning strike occurs in a nearby section, the peak attenuation of the lightning current peak value in that section is 59.8%. For sections of the main line connected to multiple branches, the average attenuation rate of the current peak value does not exceed 80%, while when a lightning strike occurs in a nearby section, the attenuation rate of the lightning current peak value in that section reaches 90%.

[0064] Based on the above principles, in this embodiment, by calculating the difference between the lightning current amplitude attenuation rate corresponding to each monitoring interval and the average lightning current amplitude attenuation rate corresponding to the interval type, monitoring intervals with a difference greater than a preset threshold are selected as candidate lightning strike intervals, thus achieving preliminary determination of the lightning strike interval. Then, based on the lightning current polarity relationship on the main line, the lightning strike interval is determined from each candidate lightning strike interval, achieving final determination of the lightning strike interval. By combining the lightning current amplitude attenuation pattern of multi-branch power lines with the lightning current polarity relationship on the main line to determine the lightning strike interval, the accuracy of lightning strike interval identification can be effectively improved, laying a good foundation for accurate location of lightning faults in the future.

[0065] The lightning strike interval is determined from each of the candidate lightning strike intervals based on the polarity relationship of the lightning current on the main line. Specifically, it is determined by whether the polarities of the lightning currents at the two ends of the candidate lightning strike interval are opposite. When the polarities of the lightning currents are opposite, it indicates that the candidate lightning strike interval contains a lightning fault point, and in this case, the candidate lightning strike interval is determined to be a lightning strike interval. When the polarities of the lightning currents are the same, it indicates that the candidate lightning strike interval does not contain a lightning fault point, and in this case, the candidate lightning strike interval is determined not to be a lightning strike interval.

[0066] It should be noted that the polarity of the lightning current can be determined using any existing method, such as the polarity of the first wavefront of the transient current line mode component of the lightning strike. This embodiment of the invention does not limit this approach.

[0067] Step S2: Based on the peak value of the lightning current collected by the distributed lightning current monitoring terminal in the lightning strike interval, select the target monitoring point from each monitoring point in the lightning strike interval.

[0068] In one possible implementation, screening out target monitoring points from each monitoring point within the lightning strike interval according to the peak value of the lightning current collected by the distributed lightning current monitoring terminals within the lightning strike interval includes:

[0069] Sorting the corresponding monitoring points in descending order of the peak value of the lightning current collected by the distributed lightning current monitoring terminals within the lightning strike interval;

[0070] Selecting the first n monitoring points before sorting as target monitoring points, where n < N, and N is the number of monitoring points within the lightning strike interval.

[0071] Step S3: Performing wavelet transform on the lightning current waveform data corresponding to each target monitoring point, taking the time point when the maximum value of the wavelet transform appears as the arrival time of the lightning fault traveling wave, and calculating the distance from the lightning fault point to the corresponding target monitoring point.

[0072] As a specific implementation, the formula for performing wavelet transform on the lightning current waveform data corresponding to each target monitoring point is as follows:

[0073]

[0074] In the formula, Wf(a,b) refers to the transform value when the frequency is a and the time is b after performing wavelet transform on the signal f(t), ψ(t) is the mother wavelet function, a is the scale factor (corresponding to frequency information), b is the translation factor (corresponding to spatio-temporal information), and ψ * (t) is the complex conjugate of ψ(t).

[0075] As a specific implementation, the calculation formula for the distance from the lightning fault point to the corresponding target monitoring point is:

[0076] L c = vt δ

[0077] In the formula, L c is the distance from the lightning fault point to the corresponding target monitoring point, v is the propagation speed of the current wave along the line, and t δ is the arrival time of the lightning fault traveling wave.

[0078] In the simulation program, set the propagation speed v of the current wave along the line to the speed of light, and t δ is obtained according to the time point when the modulus maximum value in the wavelet transform appears.

[0079] Because there are many reflections and refractions of traveling waves in multi-channel transmission lines, direct time-domain readings will have a large number of errors. In this implementation, the time point of occurrence of the wavelet transform modulus maximum is used as the arrival time of the current traveling wave front. The arrival time of the current traveling wave front at the target monitoring point is extracted, and the distance between the lightning fault point and the selected target monitoring point is calculated, which can improve the accuracy of lightning fault point location.

[0080] Step S4: Based on the distance from the lightning fault point to the corresponding target monitoring point, determine the set of lightning fault points corresponding to each target monitoring point, find the intersection of all determined sets of lightning fault points, and use the obtained intersection result as the lightning fault point of the multi-branch power line.

[0081] For a specific target monitoring point in a multi-branch distribution network, there may be multiple points at the same distance where the lightning current traveling waves arrive at that point at the same time. This means that using traveling wave theory might identify multiple lightning strike fault points. For example, for target monitoring point M1, the calculation result is a set containing 3 lightning strike fault points. For target monitoring points N2 and N3, the calculation result is a set containing 2 lightning strike fault points each. The intersection of the lightning strike fault point sets calculated for these three target monitoring points is taken as the final lightning strike fault point, thus eliminating other false lightning strike fault points.

[0082] In one feasible way, such as Figure 3 As shown, the method further includes:

[0083] Step S5: Through simulation analysis, determine the characteristics and variation law of lightning current waveforms of multi-branch control lines under different types of lightning strikes, and extract typical features for identifying lightning strike types based on the characteristics and variation law of lightning current waveforms.

[0084] The types of lightning strikes include induced lightning, direct lightning, and backflash lightning. When executing step S5, a simulation analysis model of induced lightning, direct lightning, and backflash lightning overvoltages can be established based on the actual topology and parameters of the multi-branch control line. The simulation analyzes the characteristics and variation patterns of the lightning current waveform on the line under the three types of lightning strikes, such as the lightning current amplitude and attenuation pattern, wavefront time and variation pattern, polarity and variation pattern, and pulse width and variation pattern. Typical characteristics of the lightning current waveform at each monitoring point are extracted as the basis for judging the three types of lightning strikes.

[0085] Step S6: Extract the lightning current waveform features corresponding to the lightning strike interval, and compare the extracted lightning current waveform features with each of the typical features to determine the lightning strike type.

[0086] Typical features and waveform characteristics of lightning currents can be extracted based on the characteristics of different lightning strike types. For example, the characteristics of induced lightning, direct lightning, and backflashover lightning include: when induced lightning occurs, the three-phase polarity of the wavefront collected by adjacent distributed lightning current monitoring terminals is the same; when a direct lightning strike occurs, the polarity of the current in the struck phase is opposite to that in the non-struck phase; and when a backflashover occurs, the wavefront steepness of the line current is greater due to flashover. Therefore, the three-phase polarity and steepness of the wavefront can be extracted as characteristics to determine the three types of lightning strikes.

[0087] Step S7: If the determined lightning strike type is induced lightning or direct lightning strike, determine whether a flashover has occurred on the line in the lightning strike interval, and output the corresponding line flashover determination result.

[0088] When determining whether a flashover has occurred after a lightning strike on a line, if the integral of the square of the conductor current monitored by the distributed lightning current monitoring terminal exceeds the threshold, it is determined that the corresponding line has not flashed over; otherwise, it is determined that the corresponding line has flashed over. Furthermore, the type of lightning strike is determined to be induced lightning or direct lightning strike from the perspective of lightning current polarity and three-phase balance. When induced lightning occurs, the three-phase polarity of the wavefront collected by adjacent distributed lightning current monitoring terminals is the same; when direct lightning strike occurs, the current polarity of the struck phase and the non-struck phase is opposite.

[0089] It should be noted that line flashover detection can also be achieved based on existing line flashover detection methods. This embodiment of the invention does not limit this approach.

[0090] The present invention also provides a lightning strike fault location device for multi-channel power lines.

[0091] Please see Figure 4 , Figure 4 The diagram shows a structural connection block diagram of a lightning strike fault location device for multi-line control systems provided in an embodiment of the present invention.

[0092] This invention provides a lightning strike fault location device for multi-branch power lines, comprising:

[0093] The lightning strike interval determination module 1 is used to acquire lightning current waveform data collected by each distributed lightning current monitoring terminal, analyze the lightning current amplitude attenuation law of the multi-branch power line and the polarity relationship of the lightning current on the main line based on the lightning current waveform data, and determine the lightning strike interval based on the analysis results.

[0094] The target monitoring point screening module 2 is used to screen target monitoring points from each monitoring point in the lightning strike interval based on the peak value of the lightning current collected by the distributed lightning current monitoring terminal in the lightning strike interval.

[0095] A lightning strike fault point distance calculation module 3, which is used to perform wavelet transform on the lightning current waveform data corresponding to each target monitoring point, take the time point when the maximum value of the wavelet transform appears as the arrival time of the lightning strike fault traveling wave, and calculate the distance from the lightning strike fault point to the corresponding target monitoring point;

[0096] A lightning strike fault point positioning module 4, which is used to determine the set of lightning strike fault points corresponding to each target monitoring point according to the distance from the lightning strike fault point to the corresponding target monitoring point, find the intersection of all determined sets of lightning strike fault points, and use the obtained intersection result as the lightning strike fault point of the multi-branch distribution line.

[0097] In an implementable manner, the lightning strike interval determination module 1 includes:

[0098] An interval classification unit, which is used to take the interval between two adjacent monitoring points on the main line as a monitoring interval, and determine the interval type to which each monitoring interval belongs according to the number of branch lines connected to the main line section within the monitoring interval. The interval types include an interval where no branch line is connected to the main line section, an interval where one branch line is connected to the main line section, and an interval where multiple branch lines are connected to the main line section;

[0099] A first interval determination unit, which is used to calculate the average value of the lightning current amplitude attenuation rate corresponding to each interval type according to the lightning current amplitude attenuation law, calculate the difference between the lightning current amplitude attenuation rate corresponding to each monitoring interval and the average value of the lightning current amplitude attenuation rate corresponding to the interval type to which it belongs, and take the monitoring interval with a difference greater than the preset threshold as the alternative lightning strike interval;

[0100] A second interval determination unit, which is used to determine the lightning strike interval from each alternative lightning strike interval according to the lightning current polarity relationship on the main line.

[0101] In an implementable manner, the target monitoring point screening module 2 includes:

[0102] A monitoring point sorting unit, which is used to sort the corresponding monitoring points in descending order of the lightning current peak value collected by the distributed lightning current monitoring terminals within the lightning strike interval;

[0103] A monitoring point screening unit, which is used to select the first n monitoring points as target monitoring points, where n < N, and N is the number of monitoring points within the lightning strike interval.

[0104] In an implementable manner, as Figure 5 shown, the device further includes:

[0105] Simulation analysis module 5 is used to determine the characteristics and variation law of lightning current waveforms of multi-branch power lines under different types of lightning strikes through simulation analysis, and to extract typical features for identifying lightning strike types based on the characteristics and variation law of lightning current waveforms.

[0106] The lightning strike type determination module 6 is used to extract the lightning current waveform features corresponding to the lightning strike interval, and compare the extracted lightning current waveform features with each of the typical features to determine the lightning strike type.

[0107] The line flashover judgment module 7 is used to determine whether a line in the lightning strike interval has flashed when the determined lightning strike type is induced lightning or direct lightning, and output the corresponding line flashover judgment result.

[0108] The present invention also provides a lightning strike fault location device for multi-line control systems, comprising:

[0109] A memory for storing instructions; wherein the instructions are used to implement the lightning fault location method for multi-branch control lines as described in any of the above embodiments;

[0110] A processor for executing instructions in the memory.

[0111] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for locating lightning strike faults in multi-line substations as described in any of the above embodiments.

[0112] The above embodiments of the present invention, by combining the attenuation law of lightning current amplitude of multi-branch distribution lines and the polarity relationship of lightning current on the main line to determine the lightning strike interval, can improve the accuracy of lightning strike interval determination. By screening target monitoring points from each monitoring point within the lightning strike interval, and locating the lightning fault point based on the lightning fault point set of the target monitoring points, the efficiency is improved compared to locating the lightning fault point based on the lightning fault point set of all monitoring points within the lightning strike interval. Finally, by finding the intersection of all determined lightning fault point sets, false lightning fault points are screened, further improving the accuracy of lightning fault point location. Thus, it is possible to achieve rapid and accurate location and identification of lightning faults in multi-branch distribution lines, providing a foundation for quickly troubleshooting faults in multi-branch 10kV distribution networks and rapidly restoring power supply.

[0113] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and the specific beneficial effects of the above-described device and module can be referred to the corresponding beneficial effects in the foregoing method embodiments, and will not be repeated here.

[0114] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0115] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0116] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0117] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0118] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for locating lightning faults in a multi-branch control line, wherein multiple monitoring points are spaced apart on the main line of the multi-branch control line, and one monitoring point is arranged on each branch line, and a distributed lightning current monitoring terminal is installed at each monitoring point, characterized in that, The method includes: Acquire lightning current waveform data collected by each distributed lightning current monitoring terminal, analyze the lightning current amplitude attenuation law of the multi-branch power line and the polarity relationship of the lightning current on the main line based on the lightning current waveform data, and determine the lightning strike interval based on the analysis results. Based on the peak value of the lightning current collected by the distributed lightning current monitoring terminal within the lightning strike interval, target monitoring points are selected from each monitoring point within the lightning strike interval. Wavelet transform is performed on the lightning current waveform data corresponding to each target monitoring point. The time point when the maximum value of the wavelet transform appears is taken as the arrival time of the traveling wave of the lightning fault. The distance from the lightning fault point to the corresponding target monitoring point is calculated. Based on the distance from the lightning fault point to the corresponding target monitoring point, determine the set of lightning fault points corresponding to each target monitoring point, find the intersection of all determined sets of lightning fault points, and use the obtained intersection result as the lightning fault point of the multi-branch power line. The process of determining the lightning strike zone based on the obtained analysis results includes: The interval between two adjacent monitoring points on the main line is taken as a monitoring interval. The interval type of each monitoring interval is determined according to the number of branch lines connected to the main line segment within the monitoring interval. The interval type includes intervals where the main line segment has no connected branch lines, intervals where the main line segment is connected to one branch line, and intervals where the main line segment is connected to multiple branch lines. Calculate the average lightning current amplitude attenuation rate corresponding to each interval type according to the lightning current amplitude attenuation law, calculate the difference between the lightning current amplitude attenuation rate corresponding to each monitoring interval and the average lightning current amplitude attenuation rate corresponding to the interval type, and select the monitoring interval with the difference greater than the preset threshold as the candidate lightning strike interval. The lightning strike interval is determined from each of the candidate lightning strike intervals based on the polarity relationship of the lightning current on the main line.

2. The method for locating lightning strike faults in multi-branch power lines according to claim 1, characterized in that, The step of selecting target monitoring points from among the monitoring points within the lightning strike interval based on the peak lightning current collected by the distributed lightning current monitoring terminals within the lightning strike interval includes: The monitoring points are sorted from largest to smallest based on the peak lightning current collected by the distributed lightning current monitoring terminals within the lightning strike zone. Select before sorting One monitoring point was selected as the target monitoring point, among which , This represents the number of monitoring points within the lightning strike zone.

3. The method for locating lightning strike faults in multi-branch power lines according to claim 1, characterized in that, The method further includes: The characteristics and variation patterns of lightning current waveforms in multi-channel power lines under different types of lightning strikes were determined through simulation analysis. Based on these characteristics and variation patterns, typical features for identifying lightning strike types were extracted. Extract the lightning current waveform features corresponding to the lightning strike interval, and compare the extracted lightning current waveform features with each of the typical features to determine the lightning strike type; If the determined lightning strike type is induced lightning or direct lightning, determine whether a flashover has occurred on the line in the lightning strike interval, and output the corresponding line flashover determination result.

4. A lightning fault location device for a multi-branch control line, wherein multiple monitoring points are arranged at intervals on the main line of the multi-branch control line, and one monitoring point is arranged on each branch line, and a distributed lightning current monitoring terminal is installed at each monitoring point, characterized in that, The device includes: The lightning strike interval determination module is used to acquire lightning current waveform data collected by each distributed lightning current monitoring terminal, analyze the lightning current amplitude attenuation law of the multi-branch power line and the polarity relationship of the lightning current on the main line based on the lightning current waveform data, and determine the lightning strike interval based on the analysis results. The target monitoring point screening module is used to screen target monitoring points from each monitoring point in the lightning strike interval based on the peak value of the lightning current collected by the distributed lightning current monitoring terminal in the lightning strike interval. The lightning fault point distance calculation module is used to perform wavelet transform on the lightning current waveform data corresponding to each target monitoring point, take the time point when the maximum value of the wavelet transform appears as the arrival time of the traveling wave of the lightning fault, and calculate the distance from the lightning fault point to the corresponding target monitoring point. The lightning fault point location module is used to determine the set of lightning fault points corresponding to each target monitoring point based on the distance from the lightning fault point to the corresponding target monitoring point, find the intersection of all determined sets of lightning fault points, and use the obtained intersection result as the lightning fault point of the multi-branch power line. The lightning strike zone determination module includes: The interval classification unit is used to classify the interval between two adjacent monitoring points on the main line as a monitoring interval, and to determine the interval type of each monitoring interval according to the number of branch lines connected to the main line segment within the monitoring interval. The interval type includes intervals where the main line segment has no connected branch lines, intervals where the main line segment is connected to one branch line, and intervals where the main line segment is connected to multiple branch lines. The first interval determination unit is used to calculate the average value of the lightning current amplitude attenuation rate corresponding to each interval type according to the lightning current amplitude attenuation law, calculate the difference between the lightning current amplitude attenuation rate corresponding to each monitoring interval and the average value of the lightning current amplitude attenuation rate corresponding to the interval type, and take the monitoring interval with the difference greater than the preset threshold as the candidate lightning strike interval. The second interval determination unit is used to determine the lightning strike interval from each of the candidate lightning strike intervals based on the polarity relationship of the lightning current on the main line.

5. The multi-channel power line lightning strike fault location device according to claim 4, characterized in that, The target monitoring point screening module includes: The monitoring point sorting unit is used to sort the corresponding monitoring points in descending order of the peak lightning current collected by the distributed lightning current monitoring terminal within the lightning strike interval. The monitoring point filtering unit is used to select points before sorting. One monitoring point was selected as the target monitoring point, among which , This represents the number of monitoring points within the lightning strike zone.

6. The multi-line lightning strike fault location device according to claim 4, characterized in that, The device further includes: The simulation analysis module is used to determine the characteristics and variation patterns of lightning current waveforms in multi-branch control lines under different types of lightning strikes through simulation analysis, and to extract typical features for identifying lightning strike types based on the characteristics and variation patterns of the lightning current waveforms. The lightning strike type determination module is used to extract the lightning current waveform features corresponding to the lightning strike interval, and compare the extracted lightning current waveform features with each of the typical features to determine the lightning strike type. The line flashover determination module is used to determine whether a line in the lightning strike interval has flashed when the lightning strike type is determined to be induced lightning or direct lightning, and output the corresponding line flashover determination result.

7. A lightning strike fault location device for multi-channel distribution power lines, characterized in that, include: A memory for storing instructions; wherein the instructions are used to implement the method for locating lightning strike faults in multi-branch power lines as described in any one of claims 1-3; A processor for executing instructions in the memory.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method for locating lightning strike faults in multi-line substations as described in any one of claims 1-3.

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