A cable fault locating method and device, electronic equipment and storage medium

Abstract

The application discloses a cable fault positioning method and device, electronic equipment and storage medium. It relates to the technical field of power grid. The method comprises the following steps: obtaining the impedance spectrum of a to-be-tested cable, and determining a target positioning spectrum diagram according to the impedance spectrum, wherein the target positioning spectrum diagram is used for representing the impedance abnormal state of the to-be-tested cable; sliding a first preset window on the target positioning spectrum diagram, and processing the spectrum diagram region at each sliding time by using the window function corresponding to the first preset window to obtain a first positioning spectrum diagram; and determining the fault position of the to-be-tested cable according to the first positioning spectrum diagram. The scheme provided by the application can improve the sensitivity of fault identification, avoid misjudgment and missed judgment of weak faults, and thus realizes global evaluation of the cable.

Description

Technical Field

[0001] The present invention relates to the field of power grid technology, and in particular to a cable fault locating method, device, electronic equipment and storage medium. Background Art

[0002] Grid construction involves a large number of cables. Due to various factors (such as the cable laying environment and cable aging), cable failures may occur, seriously affecting the stable operation of the power system and causing inconvenience and losses to residents. Therefore, locating cable faults is of great significance to ensuring the stable operation of the power system and extending the service life of cables.

[0003] Currently, the main methods for locating cable faults include time domain reflectometry (TDR) and frequency domain reflectometry (FDR). However, because TDR injects narrow pulse signals into the cable, these signals decay rapidly in the time domain, resulting in low fault identification sensitivity. FDR, on the other hand, is limited in its accuracy for early-stage cables or long cable lengths due to interference from ambient noise, making it impossible to fully assess the cable. Summary of the Invention

[0004] The present invention provides a cable fault location method, device, electronic device and storage medium, which can improve the sensitivity of fault identification, avoid misjudgment and omission of weak faults, and thus realize global evaluation of cables.

[0005] According to one aspect of the present invention, a cable fault location method is provided, comprising: obtaining an impedance spectrum of a cable to be tested, and determining a target location spectrum based on the impedance spectrum, wherein the target location spectrum is used to characterize an abnormal impedance state of the cable to be tested; sliding a first preset window on the target location spectrum, and processing the spectrum region at each sliding using a window function corresponding to the first preset window to obtain a first location spectrum; and determining the fault location of the cable to be tested based on the first location spectrum.

[0006] Optionally, a vector network analyzer is provided at the head end of the cable to be tested; obtaining the impedance spectrum of the cable to be tested includes: inputting incident waves of different frequencies from the head end of the cable to be tested, and collecting the impedance spectrum measured by the vector network analyzer, wherein the frequency range of the incident wave is 100KHz-50MHz.

[0007] Optionally, a target positioning spectrum is determined based on the impedance spectrum, including: performing discrete Fourier transform on the imaginary part of the impedance spectrum to obtain multiple impedance mutation points; normalizing all impedance mutation points based on an impedance mutation point with the largest reflection peak value to obtain an original positioning spectrum; and performing wavelet transform on the original positioning spectrum to obtain a target positioning spectrum.

[0008] Optionally, after obtaining the first positioning spectrum, it also includes: using a second preset window to slide on the target positioning spectrum, and using the window function corresponding to the second preset window to process the spectrum area at each sliding to obtain a second positioning spectrum; determining whether the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold; if the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to the preset threshold, continuing to execute the step of determining the fault location of the cable to be tested based on the first positioning spectrum; if the similarity between the first positioning spectrum and the second positioning spectrum is less than the preset threshold, returning to execute the step of obtaining the impedance spectrum of the cable to be tested, or using the second positioning spectrum to correct the first positioning spectrum, continuing to execute the step of determining the fault location of the cable to be tested based on the first positioning spectrum.

[0009] Optionally, the first preset window is a Blackman window; the second preset window is any one of the following: Cassel window, Gaussian window, flat-top window, rectangular window, Hanning window, and Hamming window.

[0010] Optionally, the window function corresponding to the Blackman window is the Blackman window function. The Blackman window function is Wherein, n=1, 2, ..., N-1, N represents the total length of the Blackman window function, and M represents the effective length of the Blackman window function.

[0011] Optionally, determining the fault location of the cable under test according to the first positioning spectrum includes: obtaining a peak point in the first positioning spectrum; determining the distance of the peak point relative to the head end of the cable under test, and using the distance as the fault location of the cable under test.

[0012] According to another aspect of the present invention, a cable fault locating device is provided, comprising: a measurement module, a spectrum determination module, a windowing module, and a positioning module; wherein the measurement module is used to obtain the impedance spectrum of the cable to be tested; the spectrum determination module is used to determine a target positioning spectrum based on the impedance spectrum, wherein the target positioning spectrum is used to characterize the impedance abnormality state of the cable to be tested; the windowing module is used to slide on the target positioning spectrum using a first preset window, and use a window function corresponding to the first preset window to process the spectrum area during each sliding to obtain a first positioning spectrum; and the positioning module is used to determine the fault location of the cable to be tested based on the first positioning spectrum.

[0013] According to another aspect of the present invention, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the cable fault location method according to any embodiment of the present invention.

[0014] According to another aspect of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium stores computer instructions, which are used to enable a processor to implement the cable fault location method according to any embodiment of the present invention when executed.

[0015] The technical solution of the embodiment of the present invention obtains the impedance spectrum of the cable to be tested and determines the target positioning spectrum used to characterize the impedance abnormality state of the cable to be tested, thereby using a first preset window to slide on the target positioning spectrum, and using the window function corresponding to the first preset window to process the spectrum area during each sliding to obtain a first positioning spectrum, and further determine the fault location of the cable to be tested based on the first positioning spectrum. On the one hand, this cable fault location method determines the target positioning spectrum through the impedance spectrum of the cable to be tested, which can realize the extraction of the impedance abnormality state of the cable to be tested and provide data support for subsequent processes. On the other hand, by performing a windowing operation on the target positioning spectrum, since the window function has the characteristics of simple form and low sidelobe peak, it can enhance the waveform of the fault location without increasing the difficulty of implementation, while suppressing the high-frequency sidelobe interference in the waveform diagram, thereby improving the sensitivity of subsequent fault identification, avoiding misjudgment and omission of weak faults, and realizing a global evaluation of the cable, which has good generalizability.

[0016] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are 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.

[0018] Figure 1 This is a flow chart of a cable fault location method provided by an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a model for locating a fault in a cable under test provided by an embodiment of the present invention;

[0020] Figure 3 1 is a flow chart of another cable fault location method provided by an embodiment of the present invention;

[0021] Figure 4 This is a time domain characteristic diagram of a Blackman window provided by an embodiment of the present invention;

[0022] Figure 5 This is a Blackman window normalized frequency characteristic diagram provided by an embodiment of the present invention;

[0023] Figure 6 This is a comparison diagram of results after Blackman window processing and without Blackman window processing provided by an embodiment of the present invention;

[0024] Figure 7 This is a flow chart of another cable fault location method provided by an embodiment of the present invention;

[0025] Figure 8 1 is a schematic structural diagram of a cable fault locating device provided by an embodiment of the present invention;

[0026] Figure 9 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", "target", "original", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] Figure 1This is a flow chart of a cable fault location method provided by an embodiment of the present invention. This embodiment is applicable to the situation of locating the fault position of a cable. The method can be executed by a cable fault location device. The cable fault location device can be implemented in the form of hardware and / or software. The cable fault location device can be configured in an electronic device (such as a computer device, a server, etc.). Figure 1 As shown, the method includes:

[0030] S110: Obtain an impedance spectrum of the cable to be tested, and determine a target positioning spectrum according to the impedance spectrum, wherein the target positioning spectrum is used to characterize an abnormal impedance state of the cable to be tested.

[0031] The cable fault location method provided by the present invention is suitable for locating faults in cables that are offline. The offline state refers to a cable that is powered off and inactive. In this state, the cable carries no current, ensuring safety and accurate location. The cable under test is any cable for which fault location is to be performed, and the present invention imposes no restrictions on the length or type of the cable under test.

[0032] Figure 2 This is a schematic diagram of a model for locating a fault in a cable under test provided by an embodiment of the present invention. Figure 2 As shown, the cable under test has two ends: one is the head end and the other is the tail end. The cable length is l. Assuming a fault point on the cable under test, based on transmission line theory, an incident wave input from the head end of the cable under test will change the transmission characteristics at the fault point, and the impedance spectrum of the cable under test will also change accordingly. Therefore, the impedance spectrum of the cable under test can be used to identify and locate the fault type of the cable under test. In one embodiment, fault types include but are not limited to insulation aging, insulation breakdown, connector failure, and conductor breakage.

[0033] In one embodiment, the impedance spectrum of the cable under test can be directly measured using a vector network analyzer (VNA), a radio frequency measurement instrument used to measure the performance parameters of high-frequency devices, circuits, and systems. Specifically, because the cable under test is offline, the head end of the cable under test can be directly connected to the VNA. By inputting incident waves of varying frequencies through the head end of the cable under test and directly acquiring the impedance spectrum measured by the VNA, the impedance spectrum of the cable under test can be acquired.

[0034] Optionally, the frequency of the incident wave can be selected according to actual needs, such as selecting the signal frequency when the cable to be tested is working.

[0035] After acquiring the impedance spectrum, it can be analyzed using Fourier transform to determine the target location spectrum. The target location spectrum is used to characterize the impedance anomaly of the cable under test. In other words, if the cable under test has a fault point, the impedance anomaly at the fault point will be reflected in the target location spectrum.

[0036] The Fourier transform is a method for converting a time (or space) function into a frequency function, thereby analyzing the frequency components of a signal. In the present invention, the Fourier transform can be any one of an inverse Fourier transform, a continuous Fourier transform, a discrete Fourier transform, and a fast Fourier transform.

[0037] S120 , using a first preset window to slide on the target positioning spectrum, and using a window function corresponding to the first preset window to process the spectrum area during each sliding to obtain a first positioning spectrum.

[0038] The preset window mentioned in the embodiment of the present invention is a tool for performing localized processing on a signal in the frequency domain, which can reduce the impact of discontinuities at both ends of the signal, thereby reducing spectrum leakage.

[0039] For example, the first preset window can be any of the following: Blackman window, Cassel window, Gaussian window, flat-top window, rectangular window, Hanning window, or Hamming window. Each window has its advantages and disadvantages, and the selection can be based on actual needs. For example, if spectral leakage needs to be reduced, a Hanning window or a Hamming window may be selected; if smoother window edges are required, a Gaussian window may be selected.

[0040] Preferably, the first preset window is a Blackman window. The Blackman window has the characteristics of simple form and low sidelobe peak, so it can enhance the waveform of the target positioning spectrum (especially the fault location) without increasing the difficulty of implementation, while suppressing high-frequency sidelobe interference in the waveform.

[0041] In one embodiment, the window function corresponding to the Blackman window is the Blackman window function. The Blackman window function is Wherein, n=1, 2, ..., N-1, N represents the total length of the Blackman window function, and M represents the effective length of the Blackman window function.

[0042] S130: Determine the fault location of the cable to be tested according to the first positioning spectrum.

[0043] Specifically, the first positioning spectrum can be analyzed to determine whether there is a peak in the first positioning spectrum. If there is a peak, it indicates that there is a fault in the cable under test. The distance from the peak to the beginning of the cable under test is then determined; this distance is the fault location of the cable under test. Conversely, if there is no peak in the first positioning spectrum, it indicates that there is no fault in the cable under test, and the process ends.

[0044] An embodiment of the present invention provides a cable fault location method, comprising: obtaining an impedance spectrum of a cable under test, and determining a target location spectrum based on the impedance spectrum, wherein the target location spectrum is used to characterize the impedance anomaly of the cable under test; sliding a first preset window on the target location spectrum, and processing the spectrum area during each sliding using a window function corresponding to the first preset window to obtain a first location spectrum; and determining the fault location of the cable under test based on the first location spectrum. The technical solution of the embodiment of the present invention obtains the impedance spectrum of the cable under test and determines a target location spectrum used to characterize the impedance anomaly of the cable under test, thereby sliding a first preset window on the target location spectrum, and processing the spectrum area during each sliding using a window function corresponding to the first preset window to obtain a first location spectrum, and further determining the fault location of the cable under test based on the first location spectrum. On the one hand, this cable fault location method can extract the impedance anomaly of the cable under test by determining the target location spectrum based on the impedance spectrum of the cable under test, providing data support for subsequent processes. On the other hand, by performing a windowing operation on the target positioning spectrum, due to the characteristics of the window function such as simple form and low sidelobe peak, it is possible to enhance the waveform of the fault location without increasing the difficulty of implementation, while suppressing the high-frequency sidelobe interference in the waveform, thereby improving the sensitivity of subsequent fault identification, avoiding misjudgment and omission of weak faults, and realizing a global evaluation of the cable with good scalability.

[0045] In the first possible implementation, Figure 3 This is a flow chart of another cable fault location method provided by an embodiment of the present invention. Based on the above embodiment, this embodiment introduces an optimization mechanism for the target location spectrum and a verification mechanism for the first location spectrum. Figure 3 As shown, the method includes:

[0046] S301 , inputting incident waves of different frequencies from the head end of the cable to be tested, and collecting impedance spectra measured by a vector network analyzer.

[0047] The cable fault location method provided by the present invention is based on transmission line theory. A transmission line is part of an electrical circuit, connecting a generator and a load. The performance of a transmission line depends on the ratio of its length to the wavelength λ of the electrical signal (i.e., the incident wave) entering it. λ = v / f, where v is the velocity of the electrical signal in the cable (also known as the phase velocity) and f is the frequency of the electrical signal. In the present invention, the frequency of the incident wave is typically within a wide frequency range, such as 100 kHz to 50 MHz.

[0048] When the transmission line length is much shorter than the wavelength, such as when the cable is short (i.e., a few meters) and the signal frequency is low (i.e., a few kilohertz), the line has no effect on the behavior of the circuit. Then, from the power supply side, the circuit impedance is equal to the load impedance at all times.

[0049] However, if the line length is higher than the signal wavelength (l ≥ λ), the line characteristics play an important role and the circuit impedance seen from the power supply side does not match the load, except in some very special cases.

[0050] The voltage V and current I on the cable are determined by the following differential equations, which are called telegraph equations:

[0051]

[0052] Where ω is the signal angular frequency, R is the conductor resistance, L is the inductance, C is the capacitance, and G is the insulation conductivity, all relative to the unit of cable length. These four parameters fully describe the cable's characteristics when a high-frequency signal passes through it.

[0053] In transmission line theory, the behavior of a transmission line is usually described as a function of two complex numbers. The first is the propagation function The second is the characteristic impedance

[0054] The propagation function is usually written as γ = α + jβ; where the real part α is the line attenuation constant and the imaginary part β is the propagation constant, which is related to the phase velocity v, angular frequency ω, and wavelength λ.

[0055] According to the propagation function and characteristic impedance The telegraph equation can be solved to obtain the line impedance at a distance d from the cable head end: Among them, Γ d is the generalized reflection coefficient, Γ d =Γ L e -2γd , Γ L is the load reflection coefficient, Z L is the load impedance connected at the end of the line.

[0056] It can be seen from this that when the load matches the characteristic impedance, Γ d =Γ L =0, Z d =Z0=Z L ; In all other cases, line impedance is a complex variable.

[0057] By directly connecting a vector network analyzer to the head end of the cable to be tested, inputting incident waves of different frequencies from the head end of the cable to be tested, and directly collecting the amplitude and phase of the line impedance measured by the vector network analyzer, the impedance spectrum can be obtained, thereby realizing the acquisition of the impedance spectrum of the cable to be tested.

[0058] S302 , performing discrete Fourier transform on the imaginary part of the impedance spectrum to obtain multiple impedance mutation points.

[0059] When performing Fourier transform on the impedance spectrum, the imaginary part of the impedance spectrum can be selected for discrete Fourier transform, which can reduce the computational complexity while ensuring data accuracy.

[0060] The multiple impedance mutation points obtained by performing discrete Fourier transform on the imaginary part of the impedance spectrum are caused by multiple refractions and reflections of the incident wave in the cable to be tested. The reflection peaks of the multiple impedance mutation points usually increase gradually.

[0061] S303 , taking the impedance mutation point with the largest reflection peak as a benchmark, normalizing all impedance mutation points to obtain an original positioning spectrum.

[0062] The impedance discontinuity point with the largest reflection peak is usually located at the end of the cable to be tested.

[0063] S304: Perform wavelet transform on the original positioning spectrum to obtain a target positioning spectrum.

[0064] Because slight changes in cable distribution parameters caused by subtle defects / latent defects in the normalized original positioning spectrum are difficult to observe in the spectrum, they may lead to misjudgment or missed judgment. Therefore, a wavelet transform can be performed on the original positioning spectrum to eliminate noise interference in the original positioning spectrum and obtain the target positioning spectrum.

[0065] S305 , using a first preset window to slide on the target positioning spectrum, and using a window function corresponding to the first preset window to process the spectrum area during each sliding to obtain a first positioning spectrum.

[0066] In this implementation, the first preset window is the Blackman window. Figure 4 is a time domain characteristic diagram of a Blackman window provided by an embodiment of the present invention, Figure 5 This is a Blackman window normalized frequency characteristic diagram provided by an embodiment of the present invention.

[0067] The window function corresponding to the Blackman window is the Blackman window function. The Blackman window function is Wherein, n=1, 2, ..., N-1, N represents the total length of the Blackman window function, and M represents the effective length of the Blackman window function.

[0068] The Blackman window has the characteristics of simple form and low sidelobe peak. Therefore, it can enhance the waveform of the target positioning spectrum (especially the fault location) without increasing the difficulty of implementation, while suppressing high-frequency sidelobe interference in the waveform. Figure 6 This is a comparison chart of the results of Blackman window processing and those without Blackman window processing provided by an embodiment of the present invention. Figure 6 As shown in the figure, after the Blackman window processing, two faults are located in the cable under test (such as Figure 6 The cable under test without Blackman window treatment has four faults located, that is, there are more Figure 6 The red circle in the middle shows these two faults. However, these two faults are actually misjudgments caused by high-frequency sidelobe interference. This shows that using the Blackman window to process the target positioning spectrum can significantly improve identification accuracy.

[0069] S306 , using a second preset window to slide on the target positioning spectrum, and using a window function corresponding to the second preset window to process the spectrum area during each sliding to obtain a second positioning spectrum.

[0070] In this implementation, the second preset window is any one of the following: Cassel window, Gaussian window, flat-top window, rectangular window, Hanning window, and Hamming window.

[0071] By using the second preset window to obtain the second positioning spectrum, the first positioning spectrum obtained using the first preset window can be verified to ensure the accuracy of positioning.

[0072] S307: Determine whether the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold. If so, execute S308; if not, return to execute S301.

[0073] When the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to the preset threshold, it means that the first positioning spectrum and the second positioning spectrum are basically similar, and the same fault can be located. At this time, the subsequent steps of determining the fault position of the cable to be tested can be directly executed; when the similarity between the first positioning spectrum and the second positioning spectrum is less than the preset threshold, it means that the similarity between the first positioning spectrum and the second positioning spectrum is low, and different faults may be located. At this time, in order to achieve accurate positioning, it is necessary to return to the step of obtaining the impedance spectrum of the cable to be tested to re-position.

[0074] In one embodiment, the value of the preset threshold can be set according to actual needs, such as 60%, 70%, 75%, 80%, 85%, 90%, etc.

[0075] S308: Obtain peak points in the first positioning spectrum.

[0076] S309: Determine the distance between the peak point and the head end of the cable to be tested, and use the distance as the fault location of the cable to be tested.

[0077] As can be seen from steps S308 and S309, the first positioning spectrum is analyzed to determine whether there is a peak in the spectrum. If there is a peak, it indicates a fault in the cable under test. The distance from the peak to the beginning of the cable under test is then determined; this distance is the fault location. Conversely, if there is no peak in the first positioning spectrum, it indicates no fault in the cable under test, and the process ends.

[0078] In the second possible implementation, Figure 7 This is a flow chart of another cable fault location method provided by an embodiment of the present invention. Based on the above embodiment, this embodiment introduces an optimization mechanism for the target positioning spectrum and another verification mechanism for the first positioning spectrum. Figure 7 As shown, the method includes:

[0079] S701. Input incident waves of different frequencies from the head end of the cable to be tested, and collect impedance spectra measured by a vector network analyzer.

[0080] The frequency range of the incident wave is 100KHz-50MHz.

[0081] S702 , performing discrete Fourier transform on the imaginary part of the impedance spectrum to obtain multiple impedance mutation points.

[0082] S703 , taking an impedance mutation point with the largest reflection peak as a reference, normalizing all impedance mutation points to obtain an original positioning spectrum.

[0083] S704: Perform wavelet transform on the original positioning spectrum to obtain a target positioning spectrum.

[0084] S705 , using a first preset window to slide on the target positioning spectrum, and using a window function corresponding to the first preset window to process the spectrum area during each sliding to obtain a first positioning spectrum.

[0085] S706 , using a second preset window to slide on the target positioning spectrum, and using a window function corresponding to the second preset window to process the spectrum area during each sliding to obtain a second positioning spectrum.

[0086] The related technologies of steps S701-S706 are similar to those of the above steps S301-S306. Please refer to the description of the above steps S301-S306. For the sake of brevity, they will not be repeated here.

[0087] S707: Determine whether the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold. If not, execute S708; if so, execute S709.

[0088] When the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold, it means that the first positioning spectrum and the second positioning spectrum are basically similar, and the same fault can be located. At this time, the subsequent steps of determining the fault position of the cable to be tested can be directly executed; when the similarity between the first positioning spectrum and the second positioning spectrum is less than the preset threshold, it means that the similarity between the first positioning spectrum and the second positioning spectrum is low, and different faults may be located. At this time, in order to achieve accurate positioning, the first positioning spectrum can be corrected.

[0089] In one embodiment, the value of the preset threshold can be set according to actual needs, such as 60%, 70%, 75%, 80%, 85%, 90%, etc.

[0090] S708: Use the second positioning spectrum to correct the first positioning spectrum.

[0091] Specifically, the method of correcting the first positioning spectrum using the second positioning spectrum may include but is not limited to: fusing the second positioning spectrum with the first positioning spectrum, and retaining only the fault waveforms shared by the second positioning spectrum and the first positioning spectrum.

[0092] S709: Obtain peak points in the first positioning spectrum.

[0093] S710: Determine the distance between the peak point and the head end of the cable to be tested, and use the distance as the fault location of the cable to be tested.

[0094] As can be seen from steps S709 and S710, the first positioning spectrum is analyzed to determine whether there is a peak in the spectrum. If there is a peak, it indicates a fault in the cable under test. The distance from the peak to the beginning of the cable under test is then determined; this distance is the fault location. Conversely, if there is no peak in the first positioning spectrum, it indicates no fault in the cable under test, and the process ends.

[0095] An embodiment of the present invention provides a cable fault location method, comprising: obtaining an impedance spectrum of a cable under test, and determining a target location spectrum based on the impedance spectrum, wherein the target location spectrum is used to characterize the impedance anomaly of the cable under test; sliding a first preset window on the target location spectrum, and processing the spectrum area during each sliding using a window function corresponding to the first preset window to obtain a first location spectrum; and determining the fault location of the cable under test based on the first location spectrum. The technical solution of the embodiment of the present invention obtains the impedance spectrum of the cable under test and determines a target location spectrum used to characterize the impedance anomaly of the cable under test, thereby sliding a first preset window on the target location spectrum, and processing the spectrum area during each sliding using a window function corresponding to the first preset window to obtain a first location spectrum, and further determining the fault location of the cable under test based on the first location spectrum. On the one hand, this cable fault location method can extract the impedance anomaly of the cable under test by determining the target location spectrum based on the impedance spectrum of the cable under test, providing data support for subsequent processes. On the other hand, by performing a windowing operation on the target positioning spectrum, due to the characteristics of the window function such as simple form and low sidelobe peak, it is possible to enhance the waveform of the fault location without increasing the difficulty of implementation, while suppressing the high-frequency sidelobe interference in the waveform, thereby improving the sensitivity of subsequent fault identification, avoiding misjudgment and omission of weak faults, and realizing a global evaluation of the cable with good scalability.

[0096] Figure 8 FIG. 1 is a schematic diagram of the structure of a cable fault location device provided by an embodiment of the present invention. Figure 8 As shown, the device includes: a measurement module 801, a spectrum determination module 802, a windowing module 803 and a positioning module 804.

[0097] The measurement module 801 is used to obtain the impedance spectrum of the cable to be tested;

[0098] The spectrum determination module 802 is used to determine a target positioning spectrum according to the impedance spectrum, wherein the target positioning spectrum is used to characterize the impedance abnormality state of the cable to be tested;

[0099] A windowing module 803 is configured to slide a first preset window on the target positioning spectrum, and process the spectrum region during each sliding using a window function corresponding to the first preset window to obtain a first positioning spectrum;

[0100] The positioning module 804 is configured to determine the fault location of the cable under test according to the first positioning spectrum.

[0101] Optionally, a vector network analyzer is provided at the head end of the cable to be tested; the measurement module 801 is specifically used to input incident waves of different frequencies from the head end of the cable to be tested and collect the impedance spectrum measured by the vector network analyzer, wherein the frequency range of the incident wave is 100KHz-50MHz.

[0102] Optionally, the spectrum determination module 802 is specifically used to perform discrete Fourier transform on the imaginary part of the impedance spectrum to obtain multiple impedance mutation points; normalize all impedance mutation points based on the impedance mutation point with the largest reflection peak value to obtain an original positioning spectrum; and perform wavelet transform on the original positioning spectrum to obtain a target positioning spectrum.

[0103] Optionally, the windowing module 803 is further used to slide on the target positioning spectrum using a second preset window, and use the window function corresponding to the second preset window to process the spectrum area during each sliding to obtain a second positioning spectrum; determine whether the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold; if the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to the preset threshold, the positioning module 804 continues to execute the step of determining the fault location of the cable to be tested based on the first positioning spectrum; if the similarity between the first positioning spectrum and the second positioning spectrum is less than the preset threshold, the measurement module 801 returns to execute the step of obtaining the impedance spectrum of the cable to be tested, or after correcting the first positioning spectrum using the second positioning spectrum, the positioning module 804 continues to execute the step of determining the fault location of the cable to be tested based on the first positioning spectrum.

[0104] Optionally, the first preset window is a Blackman window;

[0105] The second preset window is any one of the following: Cassel window, Gaussian window, flat-top window, rectangular window, Hanning window, and Hamming window.

[0106] Optionally, the window function corresponding to the Blackman window is the Blackman window function. The Blackman window function is

[0107] Wherein, n=1, 2, ..., N-1, N represents the total length of the Blackman window function, and M represents the effective length of the Blackman window function.

[0108] Optionally, the positioning module 804 is specifically configured to obtain a peak point in the first positioning spectrum; determine a distance between the peak point and the head end of the cable to be tested, and use the distance as the fault location of the cable to be tested.

[0109] The cable fault locating device provided in the embodiment of the present invention can execute the cable fault locating method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0110] Figure 9 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0111] like Figure 9 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., which is communicatively connected to the at least one processor 11. The memory stores a computer program that can be executed by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. Various programs and data required for the operation of the electronic device 10 can also be stored in the RAM 13. The processor 11, ROM 12, and RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0112] Multiple components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0113] The processor 11 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any other suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the cable fault location method.

[0114] In some embodiments, the cable fault location method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the cable fault location method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to execute the cable fault location method in any other suitable manner (e.g., via firmware).

[0115] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0116] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0117] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0118] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0119] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0120] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. Servers can be cloud servers, also known as cloud computing servers or cloud hosts, which are a host product in the cloud computing service system to solve the defects of great management difficulty and weak business scalability in traditional physical hosts and VPS services.

[0121] The embodiment of the present application also provides a computer program product comprising a computer program which, when executed by a processor, implements the cable fault locating method provided by any of the embodiments of the present application.

[0122] The computer program product can be written in one or more programming languages or combinations of languages including object-oriented languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0123] It should be understood that the various forms of flow shown above can be re-ordered, added to, or deleted from without departing from the scope of the present application. For example, the steps recited in the present application can be performed in parallel, in series, or in a different order, and the present application is not limited in this regard.

[0124] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A cable fault location method, characterized in that: include: Obtaining an impedance spectrum of the cable to be tested, and determining a target positioning spectrum according to the impedance spectrum, wherein the target positioning spectrum is used to characterize an abnormal impedance state of the cable to be tested; Sliding a first preset window on the target positioning spectrum, and processing the spectrum area during each sliding using a window function corresponding to the first preset window to obtain a first positioning spectrum; determining a fault location of the cable under test according to the first positioning spectrum; After obtaining the first positioning spectrum, the method further includes: Sliding a second preset window on the target positioning spectrum, and processing the spectrum area during each sliding using a window function corresponding to the second preset window to obtain a second positioning spectrum; Determining whether a similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold; If the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold, then continuing to perform the step of determining the fault location of the cable to be tested according to the first positioning spectrum; If the similarity between the first positioning spectrum and the second positioning spectrum is less than a preset threshold, the process returns to the step of obtaining the impedance spectrum of the cable to be tested, or after correcting the first positioning spectrum using the second positioning spectrum, the process continues to determine the fault location of the cable to be tested based on the first positioning spectrum.

2. The cable fault location method according to claim 1, characterized in that: The head end of the cable to be tested is provided with a vector network analyzer; the step of obtaining the impedance spectrum of the cable to be tested includes: Incident waves of different frequencies are input from the head end of the cable to be tested, and the impedance spectrum measured by the vector network analyzer is collected, wherein the frequency range of the incident wave is 100KHz-50MHz.

3. The cable fault location method according to claim 1, characterized in that: Determining a target positioning spectrum according to the impedance spectrum includes: Performing a discrete Fourier transform on the imaginary part of the impedance spectrum to obtain a plurality of impedance mutation points; Taking the impedance mutation point with the largest reflection peak as the benchmark, all impedance mutation points are normalized to obtain the original positioning spectrum; Performing wavelet transform on the original positioning spectrum to obtain the target positioning spectrum.

4. The cable fault location method according to claim 1, characterized in that: The first preset window is a Blackman window; The second preset window is any one of the following: Cassel window, Gaussian window, flat-top window, rectangular window, Hanning window, and Hamming window.

5. The cable fault location method according to claim 4, characterized in that: The window function corresponding to the Blackman window is the Blackman window function, and the Blackman window function is: ; in, , represents the total length of the Blackman window function, represents the effective length of the Blackman window function.

6. The cable fault location method according to claim 1, characterized in that: Determining the fault location of the cable to be tested according to the first positioning spectrum includes: Obtaining a peak point in the first positioning spectrum; The distance between the peak point and the head end of the cable to be tested is determined, and the distance is used as the fault location of the cable to be tested.

7. A cable fault locating device, characterized in that: include: Measurement module, spectrum determination module, windowing module and positioning module; among them, The measuring module is used to obtain the impedance spectrum of the cable to be tested; The spectrum determination module is used to determine a target positioning spectrum according to the impedance spectrum, wherein the target positioning spectrum is used to characterize the impedance abnormality state of the cable to be tested; The windowing module is configured to slide a first preset window on the target positioning spectrum, and process the spectrum area during each sliding using a window function corresponding to the first preset window to obtain a first positioning spectrum; The positioning module is configured to determine the fault location of the cable under test according to the first positioning spectrum; The windowing module is further used to slide on the target positioning spectrum using a second preset window, and use the window function corresponding to the second preset window to process the spectrum area during each sliding to obtain a second positioning spectrum; determine whether the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to a preset threshold; if the similarity between the first positioning spectrum and the second positioning spectrum is greater than or equal to the preset threshold, the positioning module continues to execute the step of determining the fault position of the cable to be tested based on the first positioning spectrum; if the similarity between the first positioning spectrum and the second positioning spectrum is less than the preset threshold, the measurement module returns to execute the step of obtaining the impedance spectrum of the cable to be tested, or after correcting the first positioning spectrum using the second positioning spectrum, the positioning module continues to execute the step of determining the fault position of the cable to be tested based on the first positioning spectrum.

8. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor. The computer program is executed by the at least one processor to enable the at least one processor to perform the cable fault locating method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the cable fault location method according to any one of claims 1 to 6 when executed.

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