A collector line single-phase grounding fault distance measurement method, device and product

Abstract

The present invention discloses a method, device and product for measuring the distance of a single-phase grounding fault of a collector line. The present invention first obtains a traveling wave signal of a target transmission line, and extracts a traveling wave head signal in the traveling wave signal; then, a multi-scale wavelet transform is performed on the traveling wave head signal, so as to obtain wavelet decomposition coefficients at different scales; then, the ratio between the modulus maxima of the wavelet decomposition coefficients at two specific frequency scales is calculated; thus, based on the ratio, the frequency component amplitude ratio of the traveling wave head signal at two specific frequencies can be determined; finally, according to the electrical parameters of the line and the frequency component amplitude ratio, the distance between the single-phase grounding fault point and the traveling wave signal collection point can be calculated; and based on the fault distance, the specific position of the single-phase grounding fault point on the line can be determined; therefore, compared with the traditional technology, the present invention not only improves the detection effect and detection efficiency, but also reduces the detection cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of power fault detection, and in particular relates to a method, device and product for measuring the distance of a single-phase grounding fault of a collector line. Background Art

[0002] High-voltage AC transmission lines are responsible for the transmission of electrical energy between power generation and consumption, and play a vital role in the operation of the power system. Single-phase grounding fault is the main type of fault in high-voltage AC transmission lines. After a line fault occurs, quickly and accurately identifying the fault location can not only quickly repair the line and restore power supply, but also has very important significance for the economic, safe and stable operation of the power grid system.

[0003] At present, the detection of single-phase grounding faults in transmission lines mainly relies on impedance analysis and injection signal methods. Among them, the impedance analysis method refers to calculating the impedance parameters of the fault circuit through the voltage and current information measured at the measuring point, and then determining the distance from the fault point to the measuring point; however, due to the uncertainty of the transition resistance of the fault point, the arc resistance during arc grounding changes dramatically, so the detection effect of the impedance method is not ideal; and the injection signal method is to manually inject a specific signal into the fault circuit, and find the fault point by detecting the vanishing point of the signal. In practical application, this method requires more equipment, requires a high-voltage power supply to re-break down the fault point, and also requires handheld detection equipment to detect signals along the line. Its automation level is low and the efficiency is slow; therefore, based on the above-mentioned shortcomings, how to provide a single-phase grounding fault distance measurement method for collector lines with good detection effect, low cost and high efficiency has become a problem to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a collector line single-phase grounding fault distance measurement method, device and product to solve the problems of poor detection effect, high cost and low efficiency in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, a method for measuring the distance of a single-phase grounding fault of a collector line is provided, comprising:

[0007] Acquire the traveling wave signal of the target transmission line, and perform wave head detection processing on the traveling wave signal to obtain a traveling wave head signal;

[0008] Performing multi-scale wavelet transform processing on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales;

[0009] Based on the wavelet decomposition coefficients at different scales, the ratio between the modulus maxima of the wavelet decomposition coefficients at the scale whose center frequency is the first preset frequency and the second preset frequency is calculated to obtain the wavelet decomposition coefficient modulus ratio;

[0010] A frequency component amplitude mapping model is constructed, wherein the frequency component amplitude mapping model is trained by taking the wavelet decomposition coefficient modulus ratio of several sample traveling wave head signals as input and the frequency component amplitude ratio of each sample traveling wave head signal as output, and the frequency component amplitude ratio of any sample traveling wave head signal is the ratio between the component amplitude of the frequency of any sample traveling wave head at the first preset frequency and the component amplitude at the second preset frequency;

[0011] Inputting the wavelet decomposition coefficient modulus ratio of the traveling wave head signal into the frequency component amplitude mapping model to obtain the frequency component amplitude ratio of the traveling wave head signal;

[0012] Calculate the fault distance according to the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, wherein the fault distance is the distance between the single-phase grounding fault point on the target transmission line and the traveling wave signal collection point on the target transmission line;

[0013] Based on the fault distance, a single-phase grounding fault point on the target transmission line is determined.

[0014] Based on the above disclosed content, the present invention first obtains the traveling wave signal of the target transmission line, and extracts the traveling wave head signal in the traveling wave signal; then, a multi-scale wavelet transform is performed on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales; then, the ratio between the modulus maxima of the wavelet decomposition coefficients at two specific frequency scales is calculated, so as to determine the frequency component amplitude ratio of the traveling wave head signal at two specific frequencies according to the ratio; wherein, the present invention pre-constructs a frequency component amplitude mapping model with the modulus ratio of the wavelet decomposition coefficients of the sample traveling wave head signal as input and the corresponding frequency component amplitude ratio as output; based on this, when actually used, the ratio between the modulus maxima at the above two specific frequencies is directly input into the model, and the frequency component amplitude ratio of the traveling wave head signal can be obtained; finally, according to the electrical parameters of the line and the frequency component amplitude ratio, the distance between the single-phase grounding fault point and the traveling wave signal collection point can be calculated; and based on the fault distance, the specific location of the single-phase grounding fault point on the line can be determined.

[0015] Through the above design, the present invention adopts the traveling wave signal on the line to perform single-phase grounding fault detection, wherein the method is not affected by load changes, transition resistance of the grounding point and intermittent arc grounding, thereby improving the detection effect; at the same time, compared with the injection signal method, the present invention collects the traveling wave signal on the line to perform fault detection, and it does not need to inject a specific signal into the fault circuit, thus avoiding the problems of the traditional injection signal method of investing a lot of equipment and requiring handheld devices to detect signals along the line; based on this, the present invention not only reduces the detection cost, but also improves the detection efficiency; therefore, it is very suitable for large-scale application and promotion in the field of single-phase grounding fault detection technology for power lines.

[0016] In a possible design, performing wave head detection processing on the traveling wave signal to obtain a traveling wave head signal includes:

[0017] Obtaining a noise signal of a target transmission line when no fault occurs, and calculating the expectation and variance of the noise signal;

[0018] According to the expectation and variance of the noise signal, filtering the traveling wave signal to obtain a filtered signal;

[0019] Performing differential processing on the filter signal and the noise signal respectively to obtain a differential filter sequence and a differential noise sequence;

[0020] Based on the differential noise sequence, a wave head calibration value is calculated;

[0021] According to the wave head calibration value, a target differential filter value is determined from the differential filter sequence, wherein the target differential filter value is the first differential filter value in the differential filter sequence that is greater than the wave head calibration value;

[0022] The sampling time corresponding to the target differential filter value is used as the arrival time of the traveling wave head;

[0023] According to the arrival time of the traveling wave head, the traveling wave head signal is extracted from the traveling wave signal.

[0024] In a possible design, obtaining the noise signal of the target transmission line when no fault occurs includes:

[0025] Acquiring a traveling wave signal of the target transmission line when no fault occurs, as a calibration traveling wave signal;

[0026] Performing mean filtering on the calibrated traveling wave signal to obtain a filtered traveling wave signal;

[0027] From the filtered traveling wave signal, a first signal point whose signal amplitude is greater than a wave head threshold is selected as a calibration point;

[0028] Based on the calibration point, a noise end point is determined, wherein the noise end point is a signal point in the filtered traveling wave signal and located n times before the calibration point, and n is a positive integer greater than 1;

[0029] The signal between the starting point and the noise end point in the filtered traveling wave signal is used as the noise signal.

[0030] In a possible design, filtering the traveling wave signal according to the expectation and variance of the noise signal to obtain a filtered signal includes:

[0031] For the i-th signal point in the traveling wave signal, based on the variance and expectation of the noise signal, calculating the filtering control factor of the i-th signal point;

[0032] According to the filtering control factor, filtering is performed on the i-th signal point to obtain the i-th signal point after filtering;

[0033] Add 1 to i, and recalculate the filter control factor of the i-th signal point based on the variance and expectation of the noise signal until i is equal to m, and obtain m filtered signal points, wherein the initial value of i is 1, and m is the total number of signal points in the traveling wave signal;

[0034] The filtered signal is composed using m filtered signal points.

[0035] In one possible design, calculating the filter control factor of the i-th signal point based on the variance and expectation of the noise signal includes:

[0036] Obtain a first target amplitude, a second target amplitude, and a third target amplitude, wherein the first target amplitude is the signal amplitude of the i-1th signal point after filtering, the second target amplitude is the signal amplitude of the i+1th signal point, and the third target amplitude is the signal amplitude of the i+2th signal point;

[0037] Calculating a difference between the second target amplitude and the first target amplitude, a difference between the third target amplitude and the first target amplitude, and a difference between the signal amplitude of the i-th signal point and the first target amplitude, so as to obtain a first intermediate parameter, a second intermediate parameter, and a third intermediate parameter, respectively;

[0038] Calculating a first filter factor, a second filter factor, and a third filter factor respectively according to the variance and expectation of the noise signal, the first intermediate parameter, the second intermediate parameter, and the third intermediate parameter;

[0039] A filter control factor is calculated using the first filter factor, the second filter factor, and the third filter factor.

[0040] In a possible design, a first filter factor, a second filter factor, and a third filter factor are calculated respectively according to the variance and expectation of the noise signal, the first intermediate parameter, the second intermediate parameter, and the third intermediate parameter, including:

[0041] Calculating the first filter factor according to the first intermediate parameter, and the variance and expectation of the noise signal;

[0042] Calculating the second filter factor based on the second intermediate parameter, and the variance and expectation of the noise signal;

[0043] Calculating the third filter factor using the third intermediate parameter, and the variance and expectation of the noise signal;

[0044] The first filter factor is calculated according to the first intermediate parameter and the variance and expectation of the noise signal, including:

[0045] According to the following formula (1), the first filter factor is calculated;

[0046]

[0047] In the above formula (1), U1 represents the first filter factor, z1 represents the first intermediate parameter, μ represents the expectation of the noise signal, σ 2 represents the variance of the noise signal, s represents the integral variable, and the integral lower limit of s is -|z1|, and the integral lower limit of s is |z1|;

[0048] Correspondingly, calculating a filtering control factor using the first filtering factor, the second filtering factor and the third filtering factor includes:

[0049] According to the following formula (2), the filtering control factor is calculated;

[0050] U′=U1×U2×U3 (2)

[0051] In the above formula (2), U′ represents the filtering control factor, U2 represents the second filtering factor, and U3 represents the third filtering factor.

[0052] In a possible design, the fault distance is calculated according to the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, including:

[0053] Calculating, according to the electrical parameters of the target power transmission line, a first frequency characteristic factor of the traveling wave head signal at the first preset frequency and a second frequency characteristic factor at the second preset frequency;

[0054] The fault distance is calculated according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency, and the frequency component amplitude ratio of the traveling wave head signal.

[0055] In a possible design, the electrical parameters of the target power transmission line include: resistance, conductance, inductance and capacitance per unit length of the target power transmission line;

[0056] The step of calculating the first frequency characteristic factor of the traveling wave head signal at the first preset frequency according to the electrical parameters of the target transmission line includes:

[0057] According to the following formula (3), the first frequency characteristic factor is calculated;

[0058]

[0059] In the above formula (3), γ1 represents the first frequency characteristic factor, ω1 represents the first preset frequency, and R, G, L, and C represent the resistance, conductance, inductance, and capacitance per unit length of the target transmission line, respectively;

[0060] Correspondingly, calculating the fault distance according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency and the frequency component amplitude ratio of the traveling wave head signal includes:

[0061] According to the following formula (4), the fault distance is calculated;

[0062]

[0063] In the above formula (4), y represents the fault distance, ω′ represents the frequency component amplitude ratio of the traveling wave head signal, ω2 represents the second preset frequency, and γ2 represents the second frequency characteristic factor.

[0064] In a second aspect, a collector line single-phase grounding fault distance measuring device is provided, comprising:

[0065] An acquisition unit, used for acquiring a traveling wave signal of a target transmission line, and performing a wave head detection process on the traveling wave signal to obtain a traveling wave wave head signal;

[0066] A signal processing unit, used for performing multi-scale wavelet transform processing on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales;

[0067] The signal processing unit is further used to calculate the ratio between the modulus maxima of the wavelet decomposition coefficients at scales with a center frequency of the first preset frequency and the second preset frequency based on the wavelet decomposition coefficients at different scales, so as to obtain the wavelet decomposition coefficient modulus ratio;

[0068] A model building unit is used to build a frequency component amplitude mapping model, wherein the frequency component amplitude mapping model is trained by taking the wavelet decomposition coefficient modulus ratio of several sample traveling wave head signals as input and the frequency component amplitude ratio of each sample traveling wave head signal as output, and the frequency component amplitude ratio of any sample traveling wave head signal is the ratio between the component amplitude of the frequency of any sample traveling wave head at a first preset frequency and the component amplitude at a second preset frequency;

[0069] an amplitude ratio calculation unit, used for inputting the wavelet decomposition coefficient modulus ratio of the traveling wave head signal into the frequency component amplitude mapping model to obtain the frequency component amplitude ratio of the traveling wave head signal;

[0070] A fault detection unit, configured to calculate a fault distance according to electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, wherein the fault distance is the distance between a single-phase grounding fault point on the target transmission line and a traveling wave signal collection point on the target transmission line;

[0071] The fault detection unit is further used to determine the single-phase grounding fault point on the target transmission line based on the fault distance.

[0072] In a third aspect, another collector line single-phase grounding fault ranging device is provided. Taking the device as an electronic device as an example, the device includes a memory, a processor and a transceiver which are communicatively connected in sequence, wherein the memory is used to store computer programs, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the collector line single-phase grounding fault ranging method as described in the first aspect or any possible design of the first aspect.

[0073] In a fourth aspect, a storage medium is provided, on which instructions are stored. When the instructions are executed on a computer, the collector line single-phase grounding fault distance measurement method as described in the first aspect or any possible design of the first aspect is executed.

[0074] In a fifth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the collector line single-phase grounding fault location measurement method as described in the first aspect or any possible design of the first aspect.

[0075] Beneficial effects:

[0076] (1) The present invention uses the traveling wave signal on the line to detect single-phase grounding faults, wherein the method is not affected by load changes, transition resistance of the grounding point and intermittent arc grounding, thereby improving the detection effect; at the same time, compared with the injection signal method, the present invention performs fault detection by collecting the traveling wave signal on the line, and it is not necessary to inject a specific signal into the fault circuit, thus avoiding the problems of the traditional injection signal method of investing a lot of equipment and requiring handheld devices to detect signals along the line; based on this, the present invention not only reduces the detection cost, but also improves the detection efficiency; therefore, it is very suitable for large-scale application and promotion in the field of single-phase grounding fault detection technology for power lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 A schematic diagram of the steps of a method for measuring the distance between a collector line and a single-phase ground fault provided by an embodiment of the present invention;

[0078] Figure 2 A schematic diagram of the structure of a collector line single-phase grounding fault distance measuring device provided by an embodiment of the present invention;

[0079] Figure 3 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0080] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0081] It should be understood that although the terms first, second, etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another unit. For example, a first unit can be referred to as a second unit, and similarly, a second unit can be referred to as a first unit without departing from the scope of the exemplary embodiments of the present invention.

[0082] It should be understood that the term "and / or" that may appear in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" that may appear in this article describes another type of association object relationship, indicating that two relationships may exist. For example, A / and B can represent two situations: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0083] Example:

[0084] See also Figure 1 As shown, the collector line single-phase grounding fault distance measurement method provided in this embodiment first obtains the traveling wave signal of the target transmission line, and extracts the traveling wave head signal in the traveling wave signal; then, a multi-scale wavelet transform is performed on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales; then, the ratio between the modulus maxima of the wavelet decomposition coefficients at two specific frequency scales is calculated; thus, the frequency component amplitude ratio of the traveling wave head signal at two specific frequencies can be determined based on the ratio; finally, the distance between the single-phase grounding fault point and the traveling wave signal collection point can be calculated according to the electrical parameters of the line and the frequency component amplitude ratio; Based on the fault distance, the specific location of the single-phase grounding fault point on the line can be determined; therefore, the present invention uses the traveling wave signal on the line to perform single-phase grounding fault detection. Compared with the traditional technology, it is not affected by factors such as the transition resistance of the grounding point, and there is no need to invest too much equipment and use handheld devices for signal detection; therefore, the present invention not only improves the detection effect and detection efficiency, but also reduces the detection cost, and thus is very suitable for large-scale application and promotion; among them, for example, the method can be but not limited to running on the single-phase grounding fault detection end side, and optionally, the single-phase grounding fault detection end can be but not limited to a personal computer (personal computer, PC). It can be understood that the aforementioned execution subject does not constitute a limitation on the embodiments of the present application. Accordingly, the operation steps of the method can be but not limited to the following steps S1 to S7.

[0085] S1. Acquire the traveling wave signal of the target transmission line, and perform wave head detection processing on the traveling wave signal to obtain a traveling wave head signal; in the specific implementation, for example, but not limited to, a voltage transformer is set on the target transmission line, so as to use the voltage transformer to collect the voltage traveling wave signal of the target transmission line; then, the collected voltage traveling wave signal is sent to the single-phase grounding fault detection end, and then used as the traveling wave signal of the aforementioned target transmission line; currently, the installation position of the aforementioned voltage transformer is used as the collection point of the traveling wave signal, which can be used to determine the specific position of the single-phase grounding fault point in the future.

[0086] In specific applications, when using traveling wave signals for single-phase grounding fault detection, it is necessary to cut out the traveling wave head. Therefore, this embodiment needs to perform head detection processing to extract the traveling wave head signal from the traveling wave signal; among them, for example, but not limited to, the following steps S11 to S17 can be used to cut out the traveling wave head signal from the traveling wave head signal.

[0087] S11. Obtain the noise signal of the target transmission line when no fault occurs, and calculate the expectation and variance of the noise signal; in specific applications, this embodiment uses the traveling wave signal of the line when no single-phase grounding fault occurs to determine the system noise of the line; wherein, the noise signal acquisition process can be but is not limited to the following steps S11a~S11e as shown.

[0088] S11 a. Acquire the traveling wave signal of the target transmission line when no fault occurs, as the calibration traveling wave signal; in this embodiment, the acquisition process of the calibration traveling wave signal can refer to the aforementioned step S1, which will not be repeated here.

[0089] After the calibration traveling wave signal is obtained, it can be filtered, and the process is shown in the following step S11 b.

[0090] S11 b. Perform mean filtering on the calibrated traveling wave signal to obtain a filtered traveling wave signal; in the present embodiment, mean filtering is a commonly used technology for signal filtering and its principle will not be described in detail; after obtaining the filtered traveling wave signal, the wave head position can be determined so as to separate the noise signal from the calibrated traveling wave signal based on the wave head position; wherein, the process of determining the wave head position can be but is not limited to as shown in the following step S11c.

[0091] S11c. Filter out the first signal point whose signal amplitude is greater than the wave head threshold from the filtered traveling wave signal as a calibration point; in the present embodiment, it is equivalent to setting a wave head threshold greater than the noise amplitude to compare one by one with the amplitude of each signal point in the filtered traveling wave signal, so as to obtain the first signal point whose signal amplitude is greater than the wave head threshold; at this time, the position of the signal point is the wave head position, based on which, it can be used as a calibration point.

[0092] After the calibration points are obtained, the noise signal can be determined based on the calibration points. The process can be, but is not limited to, as shown in the following steps S11d and S11e.

[0093] S11d. Based on the calibration point, determine the noise end point, wherein the noise end point is a signal point in the filtered traveling wave signal and located n times before the calibration point, and n is a positive integer greater than 1; in specific applications, the calibration point is used as the starting point, and the reason for using the n signal points before the starting point as the noise end point is to eliminate data of a certain time length to ensure that the remaining data does not contain traveling wave signals; of course, the aforementioned elimination time length (that is, the value of n) can be specifically set according to actual use and is not specifically limited here.

[0094] After the noise end point is determined, the noise signal can be cut out from the filtered traveling wave signal based on the noise end point, and the process can be but not limited to the following step S11e.

[0095] S11e. The signal between the starting point and the noise end point in the filtered traveling wave signal is used as the noise signal; in this embodiment, it is equivalent to using the signal before the noise end point (including the noise end point) as the noise signal.

[0096] In this way, based on the aforementioned steps S11a~S11e, after determining the system noise when the target transmission line is not faulty, its corresponding expectation and variance can be calculated based on the system noise; wherein, it is equivalent to calculating its corresponding Gaussian distribution parameters, and the maximum likelihood method can be used to calculate them; of course, the aforementioned method is a commonly used technique for noise estimation, and its principle will not be repeated here.

[0097] After the variance and expectation of the noise signal of the target transmission line are obtained, the traveling wave signal can be filtered based on the variance and expectation. The filtering process of the traveling wave signal can be but is not limited to the following step S12.

[0098] S12. According to the expectation and variance of the noise signal, the traveling wave signal is filtered to obtain a filtered signal; in specific applications, the expectation and variance of the noise signal are first used to calculate the filtering control factor of each signal point in the traveling wave signal, and then, based on this, the filtering of each signal point is completed; wherein the aforementioned filtering process can be but is not limited to the following steps S12a to S12d.

[0099] S12a. For the i-th signal point in the traveling wave signal, the filter control factor of the i-th signal point is calculated based on the variance and expectation of the noise signal; in this embodiment, the filter control factor of the i-th signal point can be calculated by, for example but not limited to, the following steps S12a1 to S12a4.

[0100] S12a1. Obtain a first target amplitude, a second target amplitude and a third target amplitude, wherein the first target amplitude is the signal amplitude of the i-1th signal point after filtering, the second target amplitude is the signal amplitude of the i+1th signal point, and the third target amplitude is the signal amplitude of the i+2th signal point; in this embodiment, it is equivalent to using the adjacent signal points of the current signal point (i.e., the last two signal points) and the amplitude of the previous signal point after filtering to calculate the filtering control factor of the current signal point.

[0101] After obtaining the first target amplitude, the second target amplitude and the third target amplitude, the intermediate parameter for calculating the filter control factor can be determined, and the calculation process can be but not limited to the one shown in the following step S12a2.

[0102] S12a2. Calculate the difference between the second target amplitude and the first target amplitude, the difference between the third target amplitude and the first target amplitude, and the difference between the signal amplitude of the i-th signal point and the first target amplitude, so as to obtain a first intermediate parameter, a second intermediate parameter and a third intermediate parameter, respectively; in this embodiment, it is equivalent to first calculating the difference between the amplitude of the i-th signal point, the amplitude of the i+1-th signal point and the amplitude of the i+2-th signal point, and the amplitude of the i-1-th signal point after filtering, so as to use the difference as the intermediate parameter.

[0103] Thus, after the three intermediate parameters are calculated, the filter factor can be calculated based on the three intermediate parameters, so as to determine the filter control factor using the filter factor; wherein, the calculation process of the filter factor can be but is not limited to the following step S12a3.

[0104] S12a3. According to the variance and expectation of the noise signal, the first intermediate parameter, the second intermediate parameter and the third intermediate parameter, a first filter factor, a second filter factor and a third filter factor are calculated respectively; in a specific implementation, the first filter factor is calculated according to the first intermediate parameter and the variance and expectation of the noise signal; then, the second filter factor is calculated based on the second intermediate parameter and the variance and expectation of the noise signal; finally, the third filter factor can be calculated using the third intermediate parameter and the variance and expectation of the noise signal.

[0105] In this embodiment, the calculation process of the above three intermediate parameters is the same, and the first filter factor is taken as an example to be specifically explained below; wherein, the first filter factor can be calculated according to the following formula (1) but is not limited thereto.

[0106]

[0107] In the above formula (1), U1 represents the first filter factor, z1 represents the first intermediate parameter, μ represents the expectation of the noise signal, σ 2 represents the variance of the noise signal, s represents the integral variable, and the integral lower limit of s is -|z1|, and the integral lower limit of s is |z1|; in this embodiment, since the traveling wave signal is a voltage traveling wave, the amplitude of each signal point is actually a voltage. Based on this, s is equivalent to the integral variable of the voltage, and its integral upper and lower limits are the negative first intermediate parameter and the positive first intermediate parameter; in this way, the first filter factor can be calculated based on the above formula (1).

[0108] Similarly, by substituting the second intermediate parameter and the third intermediate parameter into the aforementioned formula (1), the second and third filter factors can be calculated; then, the aforementioned three filter factors can be used to calculate the filter control factor of the i-th signal point, and the process is shown in the following step S12a4.

[0109] S12a4. Calculate a filter control factor using the first filter factor, the second filter factor and the third filter factor. In a specific application, the filter control factor may be calculated using, but is not limited to, the following formula (2).

[0110] U′=U1×U2×U3 (2)

[0111] In the above formula (2), U′ represents the filtering control factor, U2 represents the second filtering factor, and U3 represents the third filtering factor.

[0112] Thus, through the aforementioned steps S12a1 to S12a4, the filtering control factor of the i-th signal point can be calculated; then, the filtering of the i-th signal point can be completed based on the filtering control factor, and the process is shown in the following step S12b.

[0113] S12b. According to the filtering control factor, the i-th signal point is filtered to obtain the i-th signal point after filtering; in this embodiment, the i-th signal point can be filtered by, but not limited to, the following formula (5).

[0114] V i ′=V i ' -1 +U′·(V i -V i ' -1 ) (5)

[0115] In the above formula (5), V i represents the signal amplitude (i.e. voltage amplitude) of the ith signal point, V i ' -1It represents the first target amplitude, V i ′ represents the i-th signal point after filtering (that is, the voltage amplitude of the i-th signal point after filtering); of course, when i is 1, the first target amplitude is the initial value and can be set to 0.

[0116] Thus, based on the aforementioned formula (5), the filtering process of the i-th signal point can be completed; then, using the same principle, the filtering of the remaining signal points can be completed; wherein, the cyclic filtering process can be but is not limited to the following step S12c.

[0117] S12c. Add 1 to i and recalculate the filtering control factor of the i-th signal point based on the variance and expectation of the noise signal until i is equal to m, and m filtered signal points are obtained, where the initial value of i is 1 and m is the total number of signal points in the traveling wave signal.

[0118] After the filtering of each signal point in the traveling wave signal is completed based on the aforementioned steps S12a to S12c, the filtered signal points can be used to form a filtered signal, and the process is shown in the following step S12d.

[0119] S12d. Use the m filtered signal points to compose the filtered signal.

[0120] Therefore, through the aforementioned steps S12a to S12d, the expectation and variance of the noise signal can be used to complete the filtering processing of the traveling wave signal; then, the filtered signal and the differential signal can be used to determine the arrival time of the wave head in the traveling wave signal, and the process can be but not limited to the following steps S13 to S16.

[0121] S13. Perform differential processing on the filter signal and the noise signal respectively to obtain a differential filter sequence and a differential noise sequence; in specific implementation, for example, but not limited to, performing first-order differential processing on the aforementioned filter signal and noise signal to obtain corresponding differential filter sequence and differential noise sequence; then, the wave head calibration value can be determined based on the differential noise sequence, and the process can be but not limited to as shown in the following step S14.

[0122] S14. Based on the differential noise sequence, a wave head calibration value is calculated; in the present embodiment, there are multiple noise differential values ​​in the differential noise sequence; thus, for example, but not limited to, the largest noise differential value is screened out from the differential noise sequence; then, a wave head calibration coefficient is obtained; finally, the product of the wave head calibration coefficient and the largest noise differential value is used as the aforementioned wave head calibration value.

[0123] Thus, after obtaining the wave head calibration value, the arrival time of the wave head of the trip wave can be determined from the differential filtering sequence based on the value, and the process can be but not limited to the following steps S15 and S16.

[0124] S15. According to the wave head calibration value, a target differential filter value is determined from the differential filter sequence, wherein the target differential filter value is the first differential filter value in the differential filter sequence that is greater than the wave head calibration value; in specific applications, it is equivalent to using the wave head calibration value to compare each differential filter value in the aforementioned differential filter sequence point by point, and then selecting the first differential filter value greater than the wave head calibration value as the target differential filter value; finally, based on this, the arrival time of the wave head of the travel wave can be determined, and the process can be but not limited to as shown in the following step S16.

[0125] S16. The sampling moment corresponding to the target differential filter value is used as the arrival moment of the traveling wave head. In the present embodiment, the sampling moment corresponding to the target differential filter value (i.e., the sampling moment of the signal point in the corresponding filtered signal) is used as the arrival moment of the head. Then, based on the arrival moment, the traveling wave head signal can be intercepted, and the process can be but is not limited to the following step S17.

[0126] S17. According to the arrival time of the traveling wave head, the traveling wave head signal is intercepted from the traveling wave signal; in the present embodiment, it is equivalent to taking the arrival time as the starting point to intercept the signal, thereby obtaining the traveling wave head signal.

[0127] In this way, through the aforementioned steps S11 to S17, the traveling wave header signal can be intercepted from the traveling wave signal; then, the single-phase grounding fault of the target transmission line can be detected based on the traveling wave header signal, and the process can be but not limited to the following steps S2 to S7.

[0128] S2. Perform multi-scale wavelet transform processing on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales; in this embodiment, continuous wavelet transform at different scales can decompose the signal into several frequency bands, and these frequency bands use the frequencies corresponding to their scales as center frequencies. Therefore, by calculating the modulus ratio of the wavelet coefficients at different specific scales, the frequency component amplitude ratio of the traveling wave head signal at a specific frequency can be fitted, and thus, the fault distance of the fault point on the target transmission line can be calculated based on the frequency component amplitude ratio at different specific frequencies; of course, the aforementioned wavelet transform is a commonly used technology for signal processing, and its principle will not be repeated here.

[0129] After completing the wavelet transform processing of the traveling wave head signal, the modulus ratio of the wavelet coefficients at a specific scale can be calculated, and the process can be but not limited to the following step S3.

[0130] S3. Based on the wavelet decomposition coefficients at different scales, calculate the ratio between the modulus maxima of the wavelet decomposition coefficients at scales with the center frequency being the first preset frequency and the second preset frequency to obtain the modulus value ratio of the wavelet decomposition coefficients; in specific implementation, the aforementioned first preset frequency and the second preset frequency can be, but are not limited to, 62500 Hz and 31250 Hz respectively; of course, the set frequency can be specifically set according to actual use, and is not limited to the aforementioned example.

[0131] In this way, it is equivalent to first obtaining the ratio between the modulus maxima of the wavelet coefficients at the center frequencies of 62500HZ and 31250HZ, and then fitting the ratio of the component amplitudes of the traveling wave head signal at the two frequencies based on the modulus maxima ratio of the wavelet coefficients at the two specific scales; wherein, this embodiment constructs a frequency component amplitude mapping model for mapping the two, so that in actual use, the ratio of the frequency component amplitudes can be directly obtained according to the model; optionally, the model construction process can be but is not limited to as shown in the following step S4.

[0132] S4. Construct a frequency component amplitude mapping model, wherein the frequency component amplitude mapping model is trained by taking the wavelet decomposition coefficient modulus ratio of several sample traveling wave head signals as input and the frequency component amplitude ratio of each sample traveling wave head signal as output, and the frequency component amplitude ratio of any sample traveling wave head signal is the ratio between the component amplitude of the frequency of any sample traveling wave head at the first preset frequency and the component amplitude at the second preset frequency; in this embodiment, the BP neural network can be used as an example but not limited to be used as the frequency component amplitude mapping model.

[0133] Among them, it is equivalent to obtaining the wavelet decomposition coefficient modulus ratio of the sample traveling wave head signal of the fault point at different positions (referring to the single-phase grounding fault) as the training data, and then, using the wavelet decomposition coefficient modulus ratio and the fault distance formula (that is, the distance between the fault point and the measurement point of the traveling wave signal is known, which can be calculated according to the fault distance formula, and the fault distance formula is explained below), calculate the frequency component amplitude ratio of the sample traveling wave head signal at the aforementioned two preset frequencies; then, use the frequency component amplitude ratio as the label data of the sample traveling wave head signal; finally, the BP neural network can be trained based on the aforementioned training data and the corresponding label data, so that after the training is completed, a frequency component amplitude mapping model is obtained.

[0134] After the frequency component amplitude ratio is constructed based on the aforementioned step S4, the model can be used to obtain the frequency component amplitude ratio of the traveling wave head signal, and the process is shown in the following step S5.

[0135] S5. Inputting the wavelet decomposition coefficient modulus ratio of the traveling wave head signal into the frequency component amplitude mapping model to obtain the frequency component amplitude ratio of the traveling wave head signal.

[0136] In this way, based on the aforementioned steps S4 and S5, the ratio between the modulus maxima of the wavelet coefficients of the traveling wave head signal at two specific scales and the ratio of the frequency component amplitudes of the traveling wave head signal at two specific frequencies can be completed; then, based on the frequency component amplitude ratio of the traveling wave head signal calculated in step S5, the distance between the single-phase grounding fault point on the target transmission line and the traveling wave signal collection point can be determined; wherein, the method for determining the fault distance is shown in the following step S6.

[0137] S6. Calculate the fault distance based on the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, wherein the fault distance is the distance between the single-phase grounding fault point on the target transmission line and the traveling wave signal collection point on the target transmission line; in a specific implementation, the electrical parameters of the target transmission line may include but are not limited to: resistance, conductance, inductance and capacitance within a unit length of the target transmission line.

[0138] In this way, the first frequency characteristic factor of the traveling wave head signal at the first preset frequency and the second frequency characteristic factor at the second preset frequency can be calculated according to the electrical parameters of the target transmission line; then, the fault distance can be calculated according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency and the frequency component amplitude ratio of the traveling wave head signal.

[0139] In specific applications, the calculation process of the first frequency characteristic factor and the second frequency characteristic factor is the same, and the first frequency characteristic factor is taken as an example for explanation below; wherein, the first frequency characteristic factor can be calculated according to, but not limited to, the following formula (3).

[0140]

[0141] In the above formula (3), γ1 represents the first frequency characteristic factor, ω1 represents the first preset frequency, and R, G, L, and C represent the resistance, conductance, inductance, and capacitance per unit length of the target transmission line, respectively.

[0142] Thus, based on the aforementioned formula (3), the first frequency characteristic factor and the second frequency characteristic factor on the target transmission line can be calculated; then, based on this and in combination with the frequency component amplitude ratio of the aforementioned traveling wave head signal, the fault distance can be calculated.

[0143] Optionally, the fault distance may be calculated by, for example but not limited to, the following formula (4).

[0144]

[0145] In the above formula (4), y represents the fault distance, ω′ represents the frequency component amplitude ratio of the traveling wave head signal, ω2 represents the second preset frequency, and γ2 represents the second frequency characteristic factor.

[0146] It can be seen from the above formula (4) that when the fault distance and the specific frequency are known, the two frequency characteristic factors can be calculated; therefore, by substituting the fault distance back into the above formula (4), the frequency component amplitude ratio can be calculated; based on this, the label data of the training data in the above step S4 can be obtained, thereby realizing the training of the above model.

[0147] After calculating the distance between the single-phase grounding fault point on the target transmission line and the traveling wave signal collection point, the location of the single-phase grounding fault point can be determined based on this, and the process can be but not limited to as shown in the following step S7.

[0148] S7. Based on the fault distance, determine the single-phase grounding fault point on the target transmission line; in the present embodiment, the traveling wave signal collection point is taken as the midpoint, and the position of the single-phase grounding fault point is determined in combination with the fault distance; wherein, when the fault distance is negative, it means that it is on the left side of the traveling wave signal collection point, and vice versa, when the fault distance is positive, it means that it is on the right side of the traveling wave signal collection point; if the fault distance is -5, then it means that the single-phase grounding fault point is 5m to the left of the traveling wave signal collection point; of course, when the fault distance is other values, the process of determining the position of the single-phase grounding fault point is the same as the above example, and will not be repeated here; in this way, after determining the position of the single-phase grounding fault point, an alarm can be issued so that maintenance personnel can arrive at the fault point in time to troubleshoot the fault.

[0149] Therefore, through the collector line single-phase grounding fault distance measurement method described in detail in the aforementioned steps S1 to S7, the present invention uses the traveling wave signal on the line to perform single-phase grounding fault detection. Compared with the traditional technology, it is not affected by factors such as the transition resistance of the grounding point, and there is no need to invest too much equipment and use handheld devices for signal detection; therefore, the present invention not only improves the detection effect and detection efficiency, but also reduces the detection cost, and thus is very suitable for large-scale application and promotion.

[0150] like Figure 2 As shown, the second aspect of this embodiment provides a hardware device for implementing the collector line single-phase grounding fault distance measurement method described in the first aspect of the embodiment, including:

[0151] The acquisition unit is used to acquire the traveling wave signal of the target transmission line and perform wave head detection processing on the traveling wave signal to obtain a traveling wave wave head signal.

[0152] The signal processing unit is used to perform multi-scale wavelet transform processing on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales.

[0153] The signal processing unit is also used to calculate the ratio between the modulus maxima of the wavelet decomposition coefficients at scales with a center frequency of the first preset frequency and the second preset frequency based on the wavelet decomposition coefficients at different scales to obtain the wavelet decomposition coefficient modulus ratio.

[0154] A model construction unit is used to construct a frequency component amplitude mapping model, wherein the frequency component amplitude mapping model is trained with the wavelet decomposition coefficient modulus ratio of several sample row wave head signals as input and the frequency component amplitude ratio of each sample row wave head signal as output, and the frequency component amplitude ratio of any sample row wave head signal is the ratio between the component amplitude of the frequency of any sample row wave head at a first preset frequency and the component amplitude at a second preset frequency.

[0155] The amplitude ratio calculation unit is used to input the modulus ratio of the wavelet decomposition coefficients of the traveling wave head signal into the frequency component amplitude mapping model to obtain the frequency component amplitude ratio of the traveling wave head signal.

[0156] A fault detection unit is used to calculate the fault distance based on the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, wherein the fault distance is the distance between the single-phase grounding fault point on the target transmission line and the traveling wave signal collection point on the target transmission line.

[0157] The fault detection unit is further used to determine the single-phase grounding fault point on the target transmission line based on the fault distance.

[0158] The working process, working details and technical effects of the device provided in this embodiment can be found in the first aspect of the embodiment and will not be described in detail here.

[0159] like Figure 3 As shown, the third aspect of this embodiment provides another collector line single-phase grounding fault ranging device, taking the device as an electronic device as an example, comprising: a memory, a processor and a transceiver that are communicatively connected in sequence, wherein the memory is used to store computer programs, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the collector line single-phase grounding fault ranging method as described in the first aspect of the embodiment.

[0160] For example, the memory may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out memory (FIFO) and / or first-in-last-out memory (FILO), etc. Specifically, the processor may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). At the same time, the processor may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state.

[0161] In some embodiments, the processor may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. For example, the processor may not be limited to a microprocessor of the STM32F105 series, a reduced instruction set computer (RISC) microprocessor, an X86 or other architecture processor, or a processor with an integrated embedded neural network processor (NPU); the transceiver may be, but is not limited to, a wireless fidelity (WIFI) wireless transceiver, a Bluetooth wireless transceiver, a general packet radio service technology (Genera l Packet Rad ioService, GPRS) wireless transceiver, a ZigBee protocol (a low-power LAN protocol based on the IEEE 802.15.4 standard, ZigBee) wireless transceiver, a 3G transceiver, a 4G transceiver and / or a 5G transceiver, etc. In addition, the device may also include, but is not limited to, a power module, a display screen and other necessary components.

[0162] The working process, working details and technical effects of the electronic device provided in this embodiment can be found in the first aspect of the embodiment and will not be described in detail here.

[0163] The fourth aspect of this embodiment provides a storage medium storing instructions for the collector line single-phase grounding fault distance measurement method described in the first aspect of the embodiment, that is, the storage medium stores instructions, and when the instructions are run on a computer, the collector line single-phase grounding fault distance measurement method described in the first aspect of the embodiment is executed.

[0164] The storage medium refers to a carrier for storing data, which may include but is not limited to a floppy disk, a CD, a hard disk, a flash memory, a USB flash drive and / or a memory stick, etc. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0165] The working process, working details and technical effects of the storage medium provided in this embodiment can be found in the first aspect of the embodiment and will not be described in detail here.

[0166] The fifth aspect of this embodiment provides a computer program product containing instructions, which, when executed on a computer, enables the computer to execute the collector line single-phase grounding fault distance measurement method as described in the first aspect of the embodiment, wherein the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0167] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for measuring the distance of a single-phase grounding fault in a collector line, characterized in that: include: Acquire the traveling wave signal of the target transmission line, and perform wave head detection processing on the traveling wave signal to obtain a traveling wave head signal; Performing multi-scale wavelet transform processing on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales; Based on the wavelet decomposition coefficients at different scales, the ratio between the modulus maxima of the wavelet decomposition coefficients at the scale whose center frequency is the first preset frequency and the second preset frequency is calculated to obtain the wavelet decomposition coefficient modulus ratio; A frequency component amplitude mapping model is constructed, wherein the frequency component amplitude mapping model is trained by taking the wavelet decomposition coefficient modulus ratio of several sample traveling wave head signals as input and the frequency component amplitude ratio of each sample traveling wave head signal as output, and the frequency component amplitude ratio of any sample traveling wave head signal is the ratio between the component amplitude of the frequency of any sample traveling wave head at the first preset frequency and the component amplitude at the second preset frequency; Inputting the wavelet decomposition coefficient modulus ratio of the traveling wave head signal into the frequency component amplitude mapping model to obtain the frequency component amplitude ratio of the traveling wave head signal; Calculate the fault distance according to the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, wherein the fault distance is the distance between the single-phase grounding fault point on the target transmission line and the traveling wave signal collection point on the target transmission line; Based on the fault distance, determining a single-phase grounding fault point on the target transmission line; Calculating the fault distance according to the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal includes: Calculating, according to the electrical parameters of the target power transmission line, a first frequency characteristic factor of the traveling wave head signal at the first preset frequency and a second frequency characteristic factor at the second preset frequency; Calculating the fault distance according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency, and the frequency component amplitude ratio of the traveling wave head signal; The electrical parameters of the target power transmission line include: resistance, conductance, inductance and capacitance per unit length of the target power transmission line; The step of calculating the first frequency characteristic factor of the traveling wave head signal at the first preset frequency according to the electrical parameters of the target transmission line includes: According to the following formula (3), the first frequency characteristic factor is calculated; （3） In the above formula (3), represents the first frequency characteristic factor, Indicates the first preset frequency, represents the resistance, conductance, inductance and capacitance per unit length of the target transmission line in sequence; Correspondingly, calculating the fault distance according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency and the frequency component amplitude ratio of the traveling wave head signal includes: According to the following formula (4), the fault distance is calculated; （4） In the above formula (4), represents the fault distance, represents the frequency component amplitude ratio of the traveling wave head signal, represents the second preset frequency, represents the second frequency characteristic factor.

2. The method according to claim 1, characterized in that Performing wave head detection processing on the traveling wave signal to obtain a traveling wave head signal includes: Obtaining a noise signal of a target transmission line when no fault occurs, and calculating the expectation and variance of the noise signal; According to the expectation and variance of the noise signal, filtering the traveling wave signal to obtain a filtered signal; Performing differential processing on the filter signal and the noise signal respectively to obtain a differential filter sequence and a differential noise sequence; Based on the differential noise sequence, a wave head calibration value is calculated; Determining a target differential filter value from the differential filter sequence according to the wave head calibration value, wherein the target differential filter value is the first differential filter value in the differential filter sequence that is greater than the wave head calibration value; The sampling time corresponding to the target differential filter value is used as the arrival time of the traveling wave head; According to the arrival time of the traveling wave head, the traveling wave head signal is extracted from the traveling wave signal.

3. The method according to claim 2, characterized in that Obtain the noise signal of the target transmission line when no fault occurs, including: Acquiring a traveling wave signal of the target transmission line when no fault occurs, as a calibration traveling wave signal; Performing mean filtering on the calibrated traveling wave signal to obtain a filtered traveling wave signal; From the filtered traveling wave signal, a first signal point whose signal amplitude is greater than a wave head threshold is selected as a calibration point; Based on the calibration point, a noise end point is determined, wherein the noise end point is a signal point in the filtered traveling wave signal and located n times before the calibration point, and n is a positive integer greater than 1; The signal between the starting point and the noise end point in the filtered traveling wave signal is used as the noise signal.

4. The method according to claim 2, characterized in that: According to the expectation and variance of the noise signal, filtering the traveling wave signal to obtain a filtered signal includes: For the i-th signal point in the traveling wave signal, based on the variance and expectation of the noise signal, calculating the filtering control factor of the i-th signal point; According to the filtering control factor, filtering is performed on the i-th signal point to obtain the i-th signal point after filtering; Add 1 to i, and recalculate the filter control factor of the i-th signal point based on the variance and expectation of the noise signal until i is equal to m, and obtain m filtered signal points, wherein the initial value of i is 1, and m is the total number of signal points in the traveling wave signal; The filtered signal is composed using m filtered signal points.

5. The method according to claim 4, characterized in that Calculating the filter control factor of the i-th signal point based on the variance and expectation of the noise signal includes: Obtain a first target amplitude, a second target amplitude, and a third target amplitude, wherein the first target amplitude is the signal amplitude of the i-1th signal point after filtering, the second target amplitude is the signal amplitude of the i+1th signal point, and the third target amplitude is the signal amplitude of the i+2th signal point; Calculating a difference between the second target amplitude and the first target amplitude, a difference between the third target amplitude and the first target amplitude, and a difference between the signal amplitude of the i-th signal point and the first target amplitude, so as to obtain a first intermediate parameter, a second intermediate parameter, and a third intermediate parameter, respectively; Calculating a first filter factor, a second filter factor, and a third filter factor respectively according to the variance and expectation of the noise signal, the first intermediate parameter, the second intermediate parameter, and the third intermediate parameter; A filter control factor is calculated using the first filter factor, the second filter factor, and the third filter factor.

6. The method according to claim 5, characterized in that According to the variance and expectation of the noise signal, the first intermediate parameter, the second intermediate parameter and the third intermediate parameter, respectively calculating a first filter factor, a second filter factor and a third filter factor, including: Calculating the first filter factor according to the first intermediate parameter, and the variance and expectation of the noise signal; Calculating the second filter factor based on the second intermediate parameter, and the variance and expectation of the noise signal; Calculating the third filter factor using the third intermediate parameter, and the variance and expectation of the noise signal; The first filter factor is calculated according to the first intermediate parameter and the variance and expectation of the noise signal, including: According to the following formula (1), the first filter factor is calculated; （1） In the above formula (1), represents the first filtering factor, represents the first intermediate parameter, represents the expectation of the noise signal, represents the variance of the noise signal, represents the integration variable, and The lower limit of the integral is , The lower limit of the integral is ; Correspondingly, calculating a filtering control factor using the first filtering factor, the second filtering factor and the third filtering factor includes: According to the following formula (2), the filtering control factor is calculated; （2） In the above formula (2), represents the filtering control factor, represents the second filtering factor, represents the third filter factor.

7. A collector line single-phase grounding fault distance measuring device, characterized in that: include: An acquisition unit, used for acquiring a traveling wave signal of a target transmission line, and performing a wave head detection process on the traveling wave signal to obtain a traveling wave wave head signal; A signal processing unit, used for performing multi-scale wavelet transform processing on the traveling wave head signal to obtain wavelet decomposition coefficients at different scales; The signal processing unit is further used to calculate the ratio between the modulus maxima of the wavelet decomposition coefficients at scales with a center frequency of the first preset frequency and the second preset frequency based on the wavelet decomposition coefficients at different scales, so as to obtain the wavelet decomposition coefficient modulus ratio; A model building unit is used to build a frequency component amplitude mapping model, wherein the frequency component amplitude mapping model is trained by taking the wavelet decomposition coefficient modulus ratio of several sample traveling wave head signals as input and the frequency component amplitude ratio of each sample traveling wave head signal as output, and the frequency component amplitude ratio of any sample traveling wave head signal is the ratio between the component amplitude of the frequency of any sample traveling wave head at a first preset frequency and the component amplitude at a second preset frequency; an amplitude ratio calculation unit, used for inputting the wavelet decomposition coefficient modulus ratio of the traveling wave head signal into the frequency component amplitude mapping model to obtain the frequency component amplitude ratio of the traveling wave head signal; A fault detection unit, configured to calculate a fault distance according to electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal, wherein the fault distance is the distance between a single-phase grounding fault point on the target transmission line and a traveling wave signal collection point on the target transmission line; The fault detection unit is further used to determine the single-phase grounding fault point on the target transmission line based on the fault distance; Calculating the fault distance according to the electrical parameters of the target transmission line and the frequency component amplitude ratio of the traveling wave head signal includes: Calculating, according to the electrical parameters of the target power transmission line, a first frequency characteristic factor of the traveling wave head signal at the first preset frequency and a second frequency characteristic factor at the second preset frequency; Calculating the fault distance according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency, and the frequency component amplitude ratio of the traveling wave head signal; The electrical parameters of the target power transmission line include: resistance, conductance, inductance and capacitance per unit length of the target power transmission line; The step of calculating the first frequency characteristic factor of the traveling wave head signal at the first preset frequency according to the electrical parameters of the target transmission line includes: According to the following formula (3), the first frequency characteristic factor is calculated; （3） In the above formula (3), represents the first frequency characteristic factor, Indicates the first preset frequency, represents the resistance, conductance, inductance and capacitance per unit length of the target transmission line in sequence; Correspondingly, calculating the fault distance according to the first frequency characteristic factor, the second frequency characteristic factor, the first preset frequency, the second preset frequency and the frequency component amplitude ratio of the traveling wave head signal includes: According to the following formula (4), the fault distance is calculated; （4） In the above formula (4), represents the fault distance, represents the frequency component amplitude ratio of the traveling wave head signal, represents the second preset frequency, represents the second frequency characteristic factor.

8. A computer program product comprising instructions, characterized in that When the instructions are executed on a computer, the computer is enabled to execute a collector line single-phase grounding fault distance measurement method as claimed in any one of claims 1 to 6.

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