Lightning stroke point positioning system and device for power transmission line in alpine region

Abstract

The invention relates to the technical field of power transmission line lightning protection, in particular to a lightning stroke point positioning system and device for a power transmission line in an alpine region, and the system comprises a power transmission line voltage waveform signal obtaining module which obtains a power transmission line voltage waveform signal; the power transmission line fault waveform analysis module is used for judging a zero-mode component and a line-mode component of the voltage waveform signal of the power transmission line to obtain a lightning stroke fault moment; the lightning stroke short-circuit fault waveform analysis module analyzes the distribution condition and frequency components of the lightning stroke voltage fault signals, determines the confusion degree of voltage waveform frequency in combination with the influence of temperature data of the power transmission line at all lightning stroke fault moments on the lightning stroke voltage fault signals, and determines the confusion degree of the voltage waveform frequency based on the number of wave heads of the lightning stroke voltage fault signals of the power transmission line. Determining a traveling wave signal decomposition sub-band component value; and the lightning stroke point positioning module obtains the moment when the fault traveling wave arrives at the two ends of the power transmission line and positions the lightning stroke point. The invention aims to accurately position the fault traveling wave lightning stroke point.

Description

Technical Field

[0001] This application relates to the field of lightning protection technology for power transmission lines, specifically to a lightning strike location system and device for power transmission lines in cold regions. Background Technology

[0002] Transmission lines bear the crucial responsibility of power transmission and are the largest and most frequently faulty electronic components in the power system. Transmission lines traverse diverse and complex terrains, and as the area covered by electricity continues to expand, the location of transmission line faults and the difficulty of troubleshooting are constantly increasing. Because lightning strikes produce mostly negative polarity pulses with rapid rise and decay rates and contain a large amount of high-frequency energy, they can cause significant interference to transmission lines, leading to high-voltage transmission line tripping.

[0003] Transient lightning currents have high-frequency components and large amplitudes. Current technologies often rely on traveling wave ranging to compare and analyze the traveling and amplitude characteristics of lightning currents generated before and after a lightning strike on a high-voltage transmission line, enabling rapid location of the strike point. However, because the lightning wave generated by the strike undergoes multiple reflections and attenuations during its transmission through the busbars on both sides of the line, the arrival time of the fault traveling wavefront at the detection point cannot be accurately captured, thus causing significant interference to the location of the lightning strike point on the transmission line. Summary of the Invention

[0004] In view of the above, it is necessary to provide a lightning strike location system and device for power transmission lines in high-altitude and cold regions to solve the above problems.

[0005] The first aspect of this application provides a lightning strike location system for power transmission lines in high-altitude and cold regions, the system comprising: The transmission line voltage waveform signal acquisition module is used to acquire the transmission line voltage waveform signal, perform phase-mode transformation, and obtain the zero-mode component and line-mode component of the transmission line. The transmission line fault waveform analysis module is used to analyze the voltage waveform signal of the transmission line when a fault occurred in history. Based on the data difference between the zero-mode component and the line-mode component at the same position, a threshold segmentation method is used to obtain the optimal threshold. Based on the optimal threshold, the zero-mode component and the line-mode component of the transmission line voltage waveform signal are judged to obtain the time of the lightning strike fault. The lightning short-circuit fault waveform analysis module is used to assemble the voltage waveform signals at all lightning fault moments into a lightning voltage fault signal, analyze the distribution and frequency components of the lightning voltage fault signal, and determine the joint entropy of the transmission line lightning voltage fault signal; analyze the influence of the temperature data of the transmission line at all lightning fault moments on the lightning voltage fault signal, and determine the frequency disorder of the voltage waveform; based on the number of wavefronts of the transmission line lightning voltage fault signal, combined with the voltage waveform frequency disorder, determine the values ​​of the traveling wave signal decomposed sub-band components; The lightning strike location module decomposes the lightning voltage fault signal based on the numerical values ​​of the sub-band components of the traveling wave signal, and combines the signal energy changes of the components to obtain the time when the fault traveling wave arrives at both ends of the transmission line, thereby locating the lightning strike point.

[0006] Preferably, the specific process of obtaining the optimal threshold using the threshold segmentation method is as follows: Obtain the voltage waveform signal of the transmission line when a fault occurred in history, calculate the ratio of the zero-mode component to the line-mode component at the corresponding position element, and record it as the phase-mode component ratio. The optimal threshold is obtained by using the maximum inter-class variance method for all phase-mode component ratios, and the coefficient of variation of the phase-mode component ratios of the two types of voltage waveform signals segmented based on the optimal threshold is less than 1.

[0007] Preferably, the lightning strike fault time is specifically the time when the phase-mode component ratio of the transmission line voltage waveform signal is greater than the optimal threshold.

[0008] Preferably, the step of determining the joint entropy of the transmission line lightning voltage fault signal is as follows: A Hankel matrix is ​​constructed for the lightning voltage fault signal of the transmission line, and the singular values ​​of the matrix are calculated to obtain the Shannon entropy of the non-zero singular values. The approximate entropy of the lightning voltage fault signal of the transmission line is calculated and positively fused with the obtained Shannon entropy to obtain the joint entropy of the lightning voltage fault signal.

[0009] Preferably, determining the frequency disorder of the voltage waveform specifically involves: The average temperature of the transmission line at all times of lightning strikes is normalized, and the negative correlation mapping result of the normalized result is positively fused with the joint entropy to determine the frequency disorder of the voltage waveform.

[0010] Preferably, the specific process for determining the values ​​of the sub-band components of the traveling wave signal decomposition is as follows: Obtain the number of wavefronts of the lightning voltage fault signal of the transmission line; Calculate the sum of the natural number 1 and the frequency disorder of the voltage waveform, and take the result of the positive fusion of the sum and the number of wavefronts as the value of the sub-band component of the traveling wave signal.

[0011] Preferably, the step of decomposing the lightning voltage fault signal based on the traveling wave signal decomposed sub-band component values ​​specifically involves: using the traveling wave signal decomposed sub-band component values ​​as the number of lightning voltage fault signal decomposers, and using a decomposition algorithm to decompose the signal to obtain the lightning voltage waveform components.

[0012] Preferably, obtaining the arrival time of the fault traveling wave at both ends of the transmission line specifically involves: The energy value of each individual component obtained through the decomposition algorithm is calculated to obtain the instantaneous power spectrum; The moment when the fault traveling wave arrives at both ends of the transmission line is recorded as the moment when the fault traveling wave arrives at both ends of the transmission line.

[0013] Preferably, the specific formula for locating the lightning strike point is as follows: In the above formula, Indicates the total length of the transmission line. This indicates the propagation speed of the traveling wave from a transmission line fault. , These represent the times when the fault traveling wave arrives at the left and right ends of the transmission line, respectively. , These represent the distances between the lightning strike point and the left and right detection points, respectively.

[0014] Secondly, this application also provides a lightning strike point location device for transmission lines in cold regions, which is implemented through the aforementioned lightning strike point location system for transmission lines in cold regions.

[0015] This application has at least the following beneficial effects: The transmission line voltage waveform signal acquisition module in this application is used to acquire the transmission line voltage waveform signal and perform phase-mode transformation to decompose the signal into zero-mode and line-mode components. This transforms the complex voltage waveform signal into components that are easier to analyze, facilitating subsequent processing. Through phase-mode transformation, different mode components can be extracted from the complex voltage signal, which helps to identify potential fault modes. Especially in environments with lightning strike faults and strong electrical noise, separating the zero-mode and line-mode components helps to reduce interference and improve the accuracy of fault detection.

[0016] The power transmission line fault waveform analysis module analyzes the voltage waveform signals at historical fault times. By comparing the data differences at the same positions of the zero-mode component and the line-mode component, and using the maximum inter-class variance method to obtain the optimal threshold, the fault time can be determined. By calculating the optimal threshold, the fault type such as lightning strike can be quickly detected and determined when the fault occurs. The occurrence time of lightning strike faults can be obtained in real time and accurately, reducing the bias of human analysis and improving automation and accuracy.

[0017] The lightning short-circuit fault waveform analysis module analyzes the voltage waveform signal at the moment of a lightning strike. Based on its distribution and frequency components, it determines the joint entropy of the lightning voltage fault signal. Combining the influence of temperature data on the fault signal, it determines the frequency disorder, further providing a basis for decomposing the traveling wave signal into sub-band components. Joint entropy analysis can measure the uncertainty and complexity of the lightning voltage signal, while the calculation of frequency disorder helps identify abnormal fluctuations in the signal. These analyses help clarify the characteristics of the lightning voltage fault signal, further improving the accuracy of lightning strike location. The correlation analysis between temperature data and the fault signal enhances the reliability of the analysis model and strengthens the system's environmental adaptability.

[0018] The lightning strike location module decomposes the lightning voltage fault signal by analyzing the sub-band components of the traveling wave signal. It then combines this analysis with changes in component energy to determine the arrival times of the fault traveling wave at both ends of the transmission line, ultimately pinpointing the lightning strike point. Through signal decomposition and energy change analysis, the module accurately tracks the propagation process of the fault traveling wave and locates the lightning strike point. Combined with time analysis, this effectively reduces misjudgments and ensures precise lightning strike location. Attached Figure Description

[0019] Figure 1 A block diagram of a lightning strike location system for power transmission lines in high-altitude and cold regions, provided as an embodiment of this application; Figure 2 This is a flowchart illustrating the specific process of locating a lightning strike point according to one embodiment of this application. Detailed Implementation

[0020] In the description of the embodiments in this application, the words "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary," "or," and "for example" is intended to present the relevant concepts in a specific manner.

[0021] Unless otherwise defined, 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. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0022] It should also be noted that the terms "first" and "second" in this application and its accompanying drawings are used to distinguish similar objects, rather than to describe a specific order or sequence. The methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the method. Without departing from the scope of protection of this application, the execution order of multiple steps can be interchanged, and some steps can also be deleted.

[0023] Unless otherwise defined, 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 pertains.

[0024] The following description, in conjunction with the accompanying drawings, details the specific scheme of the lightning strike location system and device for power transmission lines in high-altitude and cold regions provided in this application.

[0025] Please see Figure 1 The illustration shows a system block diagram of a lightning strike location system for transmission lines in high-altitude and cold regions according to an embodiment of this application. The system includes: a transmission line voltage waveform signal acquisition module, a transmission line fault waveform analysis module, a lightning short-circuit fault waveform analysis module, and a lightning strike location module.

[0026] Transmission line voltage waveform signal acquisition module: acquires the transmission line voltage waveform signal, performs phase-mode transformation, and obtains the zero-mode component and line-mode component of the transmission line.

[0027] When a lightning strike short-circuit fault occurs on a high-voltage transmission line, a voltage traveling wave propagates from the point of impact to both sides of the transmission line. This traveling wave is reflected when it encounters line impedance. Voltage waveform signals are acquired using lightning interference identification elements within the transmission line, with a time window length of 2ms set for each moment. Implementers can adjust this according to actual conditions.

[0028] The lightning voltage signal generated by thunderclouds and lightning waves is mostly negative. When the lightning strikes a positive transmission line, it is equivalent to superimposing a negative polarity power source. Therefore, a phase-mode transformation is performed on the entire voltage waveform signal of the transmission line. In this embodiment, the Karrenbauer phase-mode transformation is used to obtain the zero-mode and line-mode components of the transmission line. The zero-mode component represents the relationship between each phase voltage and the ground, while the line-mode component represents the relationship between the phase voltages. The Karrenbauer phase-mode transformation is a well-known technique, and its specific calculation process will not be elaborated further.

[0029] Transmission line fault waveform analysis module: Analyzes the voltage waveform signal of the transmission line when a fault occurred in history. Based on the data difference between the zero-mode component and the line-mode component at the same position, a threshold segmentation method is used to obtain the optimal threshold. Based on the optimal threshold, the zero-mode component and the line-mode component of the transmission line voltage waveform signal are judged to obtain the time of the lightning strike fault.

[0030] Because transmission lines experience short circuits when struck by lightning, these short circuits can be either ordinary short circuits or lightning-induced short circuits. Current traveling wave ranging technology for fault location analysis of transmission lines is hampered by ordinary short circuits, which can interfere with the analysis and judgment of lightning-induced short circuits. Therefore, distinguishing between ordinary short circuits and lightning-induced short circuits in transmission lines can be achieved by calculating the optimal threshold for the phase-mode ratio of the transmission line.

[0031] When a transmission line experiences a common short-circuit fault, the voltage waveforms between different phases differ. Due to the rapid decay of the zero-mode component, it is usually smaller than the line-mode component. Furthermore, when a three-phase ground fault occurs, the zero-mode component of the transmission line is zero at the corresponding moment. However, when lightning strikes a transmission line, it is equivalent to applying a negative polarity voltage. In this case, the zero-mode and line-mode components of the transmission line have the same polarity and similar amplitude. Therefore, by analyzing the magnitudes of the zero-mode and line-mode components of the transmission line during each historical fault, the optimal threshold can be obtained, enabling rapid differentiation between common short-circuit faults and lightning-induced short-circuit faults when a transmission line fault occurs.

[0032] The specific steps are as follows: Obtain the voltage waveform signal of the transmission line when a historical fault occurred; calculate the ratio of the zero-mode component to the line-mode component at corresponding positions, denoted as the phase-mode component ratio; use the sequence of all obtained phase-mode component ratios as the transmission line phase-mode sequence; use the mean of all elements in the transmission line phase-mode sequence as the initial threshold; calculate the probability that an element is greater than or equal to the corresponding threshold, denoted as the first probability, and the probability that an element is less than the corresponding threshold, denoted as the second probability; obtain the objective function for the transmission line phase-mode ratio threshold based on the probabilities:

[0033] In the above formula: This represents the first probability of the transmission line phase mode sequence during the i-th calculation. This represents the second probability of the transmission line phase mode sequence during the i-th calculation; , , representing the average ratio of phase mode components for ordinary short-circuit faults and lightning short-circuit faults of transmission lines during the i-th calculation process; This represents the average of the ratios of all phase mode components in the phase mode sequence of a transmission line. This represents the objective function of the transmission line in the i-th calculation. , These represent the coefficients of variation of the phase-mode component ratios for ordinary short-circuit faults and lightning-induced short-circuit faults in transmission lines, respectively.

[0034] Under optimal threshold conditions, the phase mode component ratio can be used to accurately distinguish between lightning short-circuit faults and ordinary short-circuit faults in transmission lines. By traversing different data in the phase mode sequence of the transmission line, the maximum value of the objective function of the phase mode ratio threshold of the transmission line is calculated. When the objective function reaches its maximum value, it is determined that the objective function of the transmission line has converged, and the phase mode ratio corresponding to the convergence of the objective function is taken as the optimal threshold.

[0035] It should be understood that if the coefficient of variation is greater than 1, it indicates that the overall deviation of the data is small and the degree of aggregation is high. This embodiment calculates the coefficient of variation of the phase modulus data based on the lightning short-circuit fault phase modulus ratio data and the ordinary short-circuit fault phase modulus ratio data obtained after thresholding, and uses this as a constraint to distinguish fault types, ensuring the accuracy of thresholding and avoiding interference from ordinary short-circuit faults on lightning short-circuit faults.

[0036] The voltage waveform of the transmission line is analyzed using an optimal threshold. If the ratio of the zero-mode component to the line-mode component of the current transmission line is greater than the optimal threshold, it indicates that the fault type of the transmission line is a lightning short-circuit fault. Conversely, if the ratio of the zero-mode component to the line-mode component of the current transmission line is less than or equal to the optimal threshold, it indicates that the fault type of the transmission line is a normal short-circuit fault.

[0037] The lightning short-circuit fault waveform analysis module: This module assembles the voltage waveform signals at all lightning fault moments into a lightning voltage fault signal, analyzes the distribution and frequency components of the signal, and determines the joint entropy of the transmission line's lightning voltage fault signal; it also analyzes the impact of temperature data on the transmission line at all lightning fault moments on the lightning voltage fault signal, determining the voltage waveform frequency disorder; and based on the number of wavefronts in the transmission line's lightning voltage fault signal, combined with the voltage waveform frequency disorder, it determines the values ​​of the traveling wave signal decomposed into sub-band components.

[0038] When a lightning strike occurs on a transmission line, the high-voltage flashover generated at the lightning point breaks down the insulators, creating a current path to ground. In this case, the location of the lightning strike point and the short-circuit fault point on the transmission line coincide. However, if the amplitude of the lightning current is small and no high-voltage flashover occurs at the lightning strike point, the lightning current will propagate along the transmission line, causing a flashover at a weaker point in the insulation, thus forming a short-circuit fault. In this case, the lightning strike point and the lightning short-circuit fault point will not coincide. This short-circuit fault caused by the propagation of the lightning current can significantly hinder the location of the lightning current point on the transmission line. Therefore, this application analyzes the fault voltage waveform generated by the transmission line to distinguish between the lightning strike point and the short-circuit fault point in the transmission line.

[0039] When a transmission line experiences a lightning strike, a fault traveling wave is generated along the line. Since the impedance varies at different locations on the line, the fault traveling wave is reflected. Additionally, due to the inherent electromagnetic characteristics of the transmission line, noise interference signals may occur during the actual propagation process. Therefore, it is necessary to decompose and analyze the fault waveform of the transmission line.

[0040] Under normal circumstances, the impedance of transmission lines is quite sensitive to temperature changes. As temperature increases, the impedance rises, while in cold and high-altitude regions, the impedance decreases. When a fault traveling wave propagates through a transmission line with lower impedance, its signal attenuation is reduced. In cold and high-altitude regions, the impedance of the transmission line is lower than that under normal operating conditions, resulting in a more complex voltage waveform signal. Therefore, the analysis of the voltage waveform signal of the transmission line begins with an analysis of the complexity of the voltage waveform signal.

[0041] Obtain the transmission line voltage waveform signals at all times when a lightning strike fault is identified, as the lightning voltage fault signal. Construct a Hankel matrix with 4 columns and perform singular value decomposition on it to obtain the singular values ​​of the lightning voltage fault signal. Denote the number of non-zero singular values ​​as m, and calculate the joint entropy of the transmission line lightning voltage fault signal. The specific formula is as follows:

[0042] In the above formula, The approximate entropy representing the lightning voltage fault signal; This represents the frequency of the j-th non-zero singular value corresponding to the lightning voltage fault signal. Represents the logarithmic function with base 2. The joint entropy of the lightning voltage fault signal; Shannon entropy is a non-zero singular value.

[0043] Approximate entropy can reflect the frequency component state of a transmission line lightning voltage fault signal, but it is a biased estimator. Due to the discrepancy between the lightning strike point and the fault point, and the low impedance of the transmission line under extreme cold conditions, multiple reflections occur within the line. In such cases, the lightning voltage fault signal contains numerous frequency components, and approximate entropy alone cannot characterize the frequency component state. Conversely, fewer frequency components in the transmission line lightning voltage fault signal result in fewer non-zero singular values. Therefore, by decomposing the non-zero singular values ​​of the signal, the frequency component state can be obtained. When a lightning fault occurs on a transmission line, a superimposed traveling wave is generated between the fault point and the lightning strike point, leading to a more complex frequency component situation. Under these circumstances, the calculated number of non-zero singular values ​​is large, resulting in a higher joint entropy for the lightning voltage fault signal. The values ​​will also be relatively large.

[0044] In high-altitude and cold regions, the impedance of transmission lines decreases due to the drop in temperature. At this time, the lightning voltage fault signal of the transmission line will be reflected multiple times. The frequency disorder of the transmission line voltage waveform is calculated based on the temperature changes of the transmission line. Specifically, the average temperature of the transmission line at all lightning fault times is normalized. The negative correlation mapping result of the normalized result is positively fused with the joint entropy to determine the frequency disorder of the voltage waveform. In this embodiment, the normalization method uses the maximum-minimum value normalization method; the negative correlation mapping result of variable A is... The calculation is performed in the form of, where, It represents an exponential function with the natural constant as the base; it uses a multiplication method to positively combine multiple variables.

[0045] When the location of the lightning strike is different from the location of the fault, the impedance of the transmission line decreases due to the low temperature in high-altitude and cold regions. At this time, the traveling wave of the transmission line will be reflected multiple times, resulting in a more chaotic received voltage waveform signal. The calculated frequency disorder value of the transmission line voltage waveform is also relatively large.

[0046] Furthermore, the frequency disorder of the voltage waveform obtained at each time step is normalized, and the values ​​of the sub-band components of the traveling wave signal are calculated: , The normalized value representing the frequency disorder of the voltage waveform is normalized using the range method in this embodiment to ensure that its value lies within the range. superior; This indicates the number of wavefronts in the overall lightning voltage fault signal of the transmission line; simultaneously, a floor function is used. Ensure that the value of K is an integer.

[0047] Lightning strike point location module: Based on the numerical values ​​of the sub-band components of the traveling wave signal, the lightning voltage fault signal is decomposed, and combined with the signal energy changes of the components, the time when the fault traveling wave arrives at both ends of the transmission line is obtained, and the lightning strike point is located.

[0048] The VMD decomposition algorithm is used to obtain the sub-band component signal of the transmission line by decomposing the traveling wave signal into the sub-band component values ​​as the number of decompositions of the lightning voltage fault signal. When a lightning fault occurs in a transmission line, multiple waveform reflections will occur in the line. Therefore, this application uses VMD signals to decompose the voltage waveform of the transmission line under lightning conditions to obtain the lightning voltage waveform components of the transmission line. The VMD decomposition algorithm is a well-known existing technology, and this application will not elaborate on it.

[0049] When a lightning strike occurs on a transmission line, multiple voltage waveform reflections occur between the lightning strike point and the fault point. The wavefront of the fault traveling wave can be extracted using the VMD algorithm with adaptive subband number decomposition. The Teager energy value of a single component after VMD decomposition is calculated to obtain the instantaneous power spectrum. The first peak moment on the instantaneous power spectrum is the moment when the fault traveling wave arrives at both ends of the transmission line.

[0050]

[0051] In the above formula, Indicates the total length of the transmission line. This indicates the propagation speed of the traveling wave from a transmission line fault. , These represent the times when the fault traveling wave arrives at the left and right ends of the transmission line, respectively. , These represent the distances between the lightning strike point and the left and right detection points, respectively.

[0052] Thus, the location of the lightning strike point on the transmission line in the high-altitude and cold region is obtained. The specific flowchart for locating the lightning strike point is as follows: Figure 2 As shown.

[0053] Based on the same inventive concept as the above method, this application embodiment also provides a lightning strike point location device for transmission lines in high-altitude and cold regions, which is implemented through the aforementioned lightning strike point location system for transmission lines in high-altitude and cold regions.

[0054] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description; sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

[0055] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from its essential characteristics. Therefore, the embodiments described above should be considered exemplary and non-limiting in all respects; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some technical features, without causing the essence of the corresponding technical solutions to deviate from the scope of the technical solutions in the embodiments of this application, should all be included within the protection scope of this application.

Claims

1. A lightning strike location system for power transmission lines in high-altitude and cold regions, characterized in that, The system includes: The transmission line voltage waveform signal acquisition module is used to acquire the transmission line voltage waveform signal, perform phase-mode transformation, and obtain the zero-mode component and line-mode component of the transmission line. The transmission line fault waveform analysis module is used to analyze the voltage waveform signal of the transmission line when a fault occurred in history. Based on the data difference between the zero-mode component and the line-mode component at the same position, a threshold segmentation method is used to obtain the optimal threshold. Based on the optimal threshold, the zero-mode component and the line-mode component of the transmission line voltage waveform signal are judged to obtain the time of the lightning strike fault. The lightning short-circuit fault waveform analysis module is used to assemble the voltage waveform signals at all lightning fault moments into a lightning voltage fault signal, analyze the distribution and frequency components of the lightning voltage fault signal, and determine the joint entropy of the transmission line lightning voltage fault signal; analyze the influence of the temperature data of the transmission line at all lightning fault moments on the lightning voltage fault signal, and determine the frequency disorder of the voltage waveform; based on the number of wavefronts of the transmission line lightning voltage fault signal, combined with the voltage waveform frequency disorder, determine the values ​​of the traveling wave signal decomposed sub-band components; The lightning strike location module decomposes the lightning voltage fault signal based on the numerical values ​​of the sub-band components of the traveling wave signal, and combines the signal energy changes of the components to obtain the time when the fault traveling wave arrives at both ends of the transmission line, thereby locating the lightning strike point.

2. The lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The specific process of obtaining the optimal threshold using the threshold segmentation method is as follows: Obtain the voltage waveform signal of the transmission line when a fault occurred in history, calculate the ratio of the zero-mode component to the line-mode component at the corresponding position element, and record it as the phase-mode component ratio. The optimal threshold is obtained by using the maximum inter-class variance method for all phase-mode component ratios, and the coefficient of variation of the phase-mode component ratios of the two types of voltage waveform signals segmented based on the optimal threshold is less than 1.

3. The lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 2, characterized in that, The specific time of the lightning strike fault is the moment when the phase-mode component ratio of the transmission line voltage waveform signal is greater than the optimal threshold.

4. The lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The steps for determining the joint entropy of the transmission line lightning voltage fault signal are as follows: A Hankel matrix is ​​constructed for the lightning voltage fault signal of the transmission line, and the singular values ​​of the matrix are calculated to obtain the Shannon entropy of the non-zero singular values. The approximate entropy of the lightning voltage fault signal of the transmission line is calculated and positively fused with the obtained Shannon entropy to obtain the joint entropy of the lightning voltage fault signal.

5. A lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The determination of the voltage waveform frequency disorder is specifically as follows: The average temperature of the transmission line at all times of lightning strikes is normalized, and the negative correlation mapping result of the normalized result is positively fused with the joint entropy to determine the frequency disorder of the voltage waveform.

6. A lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The specific process for determining the values ​​of the sub-band components of the traveling wave signal is as follows: Obtain the number of wavefronts of the lightning voltage fault signal of the transmission line; Calculate the sum of the natural number 1 and the frequency disorder of the voltage waveform, and take the result of the positive fusion of the sum and the number of wavefronts as the value of the sub-band component of the traveling wave signal.

7. A lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The specific steps of decomposing the lightning voltage fault signal based on the traveling wave signal decomposition sub-band component values ​​are as follows: the traveling wave signal decomposition sub-band component values ​​are used as the number of lightning voltage fault signal decompositions, and a decomposition algorithm is used to decompose the signal to obtain the lightning voltage waveform components.

8. A lightning strike location system for power transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The specific steps for obtaining the arrival times of the fault traveling wave at both ends of the transmission line are as follows: The energy value of each individual component obtained through the decomposition algorithm is calculated to obtain the instantaneous power spectrum; The moment when the fault traveling wave arrives at both ends of the transmission line is recorded as the moment when the fault traveling wave arrives at both ends of the transmission line.

9. A lightning strike location system for transmission lines in high-altitude and cold regions as described in claim 1, characterized in that, The specific formula for locating the lightning strike point is as follows: In the above formula, Indicates the total length of the transmission line. This indicates the propagation speed of the traveling wave from a transmission line fault. , These represent the times when the fault traveling wave arrives at the left and right ends of the transmission line, respectively. , These represent the distances between the lightning strike point and the left and right detection points, respectively.

10. A lightning strike location device for power transmission lines in high-altitude and cold regions, characterized in that, The device is implemented using a lightning strike point location system for power transmission lines in cold regions as described in claim 1.

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