Cable fault location positioning method and device and electronic equipment

Abstract

The invention discloses a cable fault location positioning method and device and electronic equipment. The method relates to the technical field of cable tunnels, and comprises the following steps: acquiring first current signal information acquired by a first current transformer mounted at a first acquisition position in a cable line and second current signal information acquired by a second current transformer mounted at a second acquisition position in the cable line; respectively performing frequency domain conversion to obtain a first current spectrum and a second current spectrum; current amplitude sets matched with the at least one target characteristic harmonic wave are extracted from the first current frequency spectrum and the second current frequency spectrum respectively; under the condition that the target current amplitude greater than the target threshold exists in the current amplitude set, determining the time difference between the time when the signal arrives at the first acquisition position and the time when the signal arrives at the second acquisition position under the target characteristic harmonic; and determining a fault position on the cable line according to the time difference and the propagation speed of the signal. According to the invention, the problem of inaccurate cable fault position in the prior art is solved.

Description

Technical Field

[0001] This application relates to the field of cable tunnel technology, and more specifically, to a method, apparatus, and electronic device for locating cable faults. Background Technology

[0002] The buffer layer (also known as the shielding layer or sheath) is mainly used to provide mechanical protection, prevent moisture intrusion, and provide a uniform electric field. During long-term operation of the cable, especially under conditions such as overload, insulation aging, or manufacturing or installation defects, the buffer layer may be damaged or ablated. The development process of buffer layer ablation defects will generate electrical signals.

[0003] However, due to the weak and noisy nature of existing detection signals, and the weak electrical signals generated by ablation defects often mixed with power frequency interference, traditional sensors and signal processing techniques are prone to misjudgment or missed detection. Furthermore, existing technologies cannot achieve continuous online monitoring; most monitoring methods still rely on power outage sampling or disassembly analysis, lacking long-term deployment and real-time response capabilities, making it difficult to achieve real-time status perception. There is a lack of standardized feature extraction indicators, and a unified quantitative evaluation system for the electrical response characteristics of ablation defects has not yet been established, leading to reliance on experience in diagnosis and poor versatility. Currently, no effective solution has been proposed to address the technical problem of inaccurate cable fault location determination in related technologies. Summary of the Invention

[0004] The main objective of this application is to provide a method, apparatus, and electronic device for locating cable faults based on their locations, in order to solve the technical problem of inaccurate determination of the location of cable faults in related technologies.

[0005] To achieve the above objectives, according to one aspect of this application, a method for locating cable faults is provided. The method includes: performing frequency domain transformation on first current signal information collected by a first current transformer installed at a first acquisition location in the cable line, and second current signal information collected by a second current transformer installed at a second acquisition location in the cable line, respectively, to obtain a first current spectrum and a second current spectrum. The first and second acquisition locations are two adjacent joint locations on the cable line. The measurement frequencies of the first and second current transformers meet low-frequency response requirements. The first and second current signal information are used to indicate changes in current intensity. The method further includes: extracting sets of current amplitudes matching at least one target characteristic harmonic from the first and second current spectra, respectively, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency; determining the time difference between the arrival of the signal under the target characteristic harmonic at the first acquisition location and its arrival at the second acquisition location when a target current amplitude greater than a target threshold exists in the current amplitude set; and determining the fault location on the cable line based on the time difference and the signal propagation speed.

[0006] To achieve the above objectives, according to another aspect of this application, a cable fault location device is provided. The device includes: a current acquisition module, which performs frequency domain conversion on first current signal information acquired by a first current transformer installed at a first acquisition location in the cable line and second current signal information acquired by a second current transformer installed at a second acquisition location in the cable line to obtain a first current spectrum and a second current spectrum, wherein the first acquisition location and the second acquisition location are two adjacent joint locations on the cable line, the measurement frequencies of the first current transformer and the second current transformer meet low-frequency response requirements, and the first current signal information and the second current signal information are used to indicate changes in current intensity; a signal processing module, which extracts sets of current amplitude values ​​matching at least one target characteristic harmonic from the first current spectrum and the second current spectrum, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency; a time difference location module, which, when there is a target current amplitude value greater than a target threshold in the current amplitude value set, determines the time difference between the arrival of the signal under the target characteristic harmonic at the first acquisition location and its arrival at the second acquisition location; and a fault location module, which determines the fault location on the cable line based on the time difference and the signal propagation speed.

[0007] To achieve the above objectives, according to another aspect of this application, a computer-readable storage medium is provided, wherein a computer program is stored in the computer program, which is configured to execute the above-described method for locating the cable fault location when it is run.

[0008] To achieve the above objectives, according to another aspect of this application, a computer program product or computer program is provided, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the aforementioned method for locating the cable fault location.

[0009] To achieve the above objectives, according to another aspect of this application, a processor is provided for running a program, wherein the program executes the method for locating the cable fault location.

[0010] To achieve the above objectives, according to another aspect of this application, an electronic device is provided, including one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are run by the one or more processors, the one or more processors cause the one or more processors to perform the cable fault location location method.

[0011] This application employs the following steps: First, the first current signal information collected by the first current transformer installed at the first acquisition location in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition location in the cable line are respectively converted into the frequency domain to obtain the first current spectrum and the second current spectrum; from the first current spectrum and the second current spectrum, a set of current amplitude values ​​matching at least one target characteristic harmonic is extracted; if there is a target current amplitude value in the current amplitude set that is greater than the target threshold, the time difference between the arrival of the signal under the target characteristic harmonic at the first acquisition location and the arrival at the second acquisition location is determined; then, based on the time difference and the signal propagation speed, the fault location on the cable line is determined, thus solving the technical problem of inaccurate fault location in related technologies. Attached Figure Description

[0012] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0013] Figure 1 This is a flowchart of a cable fault location method provided according to an embodiment of this application;

[0014] Figure 2 This is a flowchart of another method for locating cable faults according to an embodiment of this application;

[0015] Figure 3 This is a schematic diagram of an optional cable fault location locating device provided according to an embodiment of this application;

[0016] Figure 4 This is a schematic diagram of an optional electronic device provided according to an embodiment of this application. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] The cable fault location method, device, and electronic equipment in this application can be used in the field of cable tunnel technology, and the application fields of the cable fault location method, device, and electronic equipment in this application are not limited.

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] It should be noted that all information and data disclosed herein are authorized by the user or fully authorized by all parties. The acquisition, storage, and processing of data involved in this application comply with relevant regulations. The collected information is authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of related data all comply with relevant laws, regulations, and standards of the relevant regions, necessary confidentiality measures have been taken, and there is no violation of public order and good morals. Corresponding access points are provided for users to choose to authorize or refuse authorization.

[0022] The present invention will now be described in conjunction with preferred implementation steps. Figure 1 This is a flowchart of a cable fault location method provided according to an embodiment of this application, such as... Figure 1 As shown, the method includes the following steps:

[0023] S102, the first current signal information collected by the first current transformer installed at the first acquisition position in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition position in the cable line are respectively converted into the frequency domain to obtain the first current spectrum and the second current spectrum. The first acquisition position and the second acquisition position are two adjacent joint positions on the cable line. The measurement frequency of the first current transformer and the second current transformer meets the low frequency response requirement. The first current signal information and the second current signal information are used to indicate the change of current intensity.

[0024] S104, extract the set of current amplitudes that match at least one target characteristic harmonic from the first current spectrum and the second current spectrum respectively, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency;

[0025] S106, if there is a target current amplitude greater than the target threshold in the current amplitude set, determine the time difference between the signal under the target characteristic harmonic reaching the first acquisition position and the second acquisition position;

[0026] S108 determines the location of the fault on the cable line based on the time difference and the speed of signal propagation.

[0027] In step S102 above, the first current signal information collected by the first current transformer installed at the first acquisition position in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition position in the cable line are respectively converted into the frequency domain to obtain the first current spectrum and the second current spectrum. The first acquisition position and the second acquisition position are two adjacent joint positions on the cable line. The measurement frequencies of the first current transformer and the second current transformer meet the low frequency response requirements. The first current signal information and the second current signal information are used to indicate the change in current intensity.

[0028] Optionally, this application employs a current transformer with good low-frequency response characteristics, installed at the grounding lead of the grounding box of the high-voltage cable intermediate joint, to collect grounding current signals in real time, enabling accurate measurement of current changes in the frequency range below 1kHz; the first current signal information and the second current signal information are the original time-domain signals of the current changes collected by the transformer, reflecting the change of current intensity over time; the frequency domain conversion can be achieved by using Fourier transform (FFT) to convert the time-domain signal to the frequency domain for analysis of frequency components.

[0029] As an optional implementation, low-frequency current transformers T1 and T2 are installed at two adjacent joints of the cable to ensure that the transformers operate in the frequency range of 0~1kHz to accurately capture harmonic currents. The transformers acquire grounding current signals in real time to obtain time-domain current sequences i_1(t) and i_2(t). Fourier transforms are performed on these two sets of current sequences to obtain their corresponding frequency-domain current spectra I_1(f) and I_2(f), where f is the frequency.

[0030] In step S104 above, a set of current amplitudes matching at least one target characteristic harmonic is extracted from the first current spectrum and the second current spectrum, respectively, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency; optionally, the target characteristic harmonic is, for example, a low-order harmonic such as the 5th harmonic or the 7th harmonic.

[0031] As an alternative implementation, in the frequency domain signals I_1(f) and I_2(f), the set of current amplitudes that match the frequencies of the 5th harmonic (5f0) and the 7th harmonic (7f0) are identified and denoted as {A_5-1,A_7-1} and {A_5-2,A_7-2}.

[0032] In step S106 above, if there is a target current amplitude greater than the target threshold in the current amplitude set, the time difference between the signal under the target characteristic harmonic reaching the first acquisition position and reaching the second acquisition position is determined. For example, the signal reaches the second acquisition position at time t2 and the first acquisition position at time t1, and the time difference Δt = t2 - t1.

[0033] As an optional implementation, a fault warning threshold of 1000A is set. For each characteristic harmonic (5th and 7th), if the amplitude of either {A_5-1,A_7-1} or {A_5-2,A_7-2} exceeds 1000A, the system determines that there is a potential fault in the cable. Signal analysis techniques, such as zero-crossing or peak detection, are further used to determine the arrival time of each characteristic harmonic signal at T1 and T2, and to determine the time difference between the signal arriving at T2 from the fault point and arriving at T1 from the fault point.

[0034] In step S108 above, the location of the fault on the cable line is determined based on the time difference and the speed of signal propagation.

[0035] It is understandable that the propagation time difference t2-t1 of the signal from the fault point to T1 and T2 is positive, indicating that the signal arrives at T2 later than it arrives at T1. That is, the signal generated at the fault point arrives at T1 first and then reaches T2. In this case, the fault point is located at a point between T1 and T2. Assuming the distance to T1 is (d), the straight-line distance of the signal from the fault point to T1 is (d), so the time required for the signal to reach T1 from the fault point is d / v. For the same signal, the distance from the fault point to T2 is (Ld), and the time required for the signal to reach T2 from the fault point is (Ld) / v. The time difference Δt=(Ld) / vd / v=(L-2d) / v, then d=(L-Δt×v) / 2.

[0036] When the time difference is negative, it means that the signal arrives at T2 earlier than it arrives at T1, indicating that the fault point is located outside T1. It is necessary to add a sampling point T3 on the other side of the cable to obtain the time information of the signal from the fault point to T3. Then, compare the time difference between T1 and T3, and between T2 and T3. Combined with the wave velocity of the cable signal, the actual position of the fault point relative to T1, T2 and T3 is calculated by the triangulation algorithm to locate the cable fault point.

[0037] The cable fault location method provided in this application performs frequency domain transformation on the first current signal information collected by the first current transformer installed at the first acquisition position in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition position in the cable line to obtain the first current spectrum and the second current spectrum, respectively. Through frequency domain transformation, specific harmonic components caused by cable faults are separated and identified, which improves the accuracy of signal analysis, reduces the impact of noise on measurement, and helps to more accurately detect the current frequency characteristics related to the fault. The method extracts the current amplitude set that matches at least one target characteristic harmonic from the first current spectrum and the second current spectrum, respectively, filtering out a large number of irrelevant frequency components and focusing attention on those signals that are highly correlated with the fault. When there is a target current amplitude greater than the target threshold in the current amplitude set, the time difference between the signal under the target characteristic harmonic reaching the first acquisition position and reaching the second acquisition position is determined. Based on the time difference and the signal propagation speed, the fault location on the cable line is determined, which solves the problem of coarse and inaccurate fault location in related technologies and realizes non-contact, real-time cable fault location.

[0038] As an optional approach, the above-mentioned frequency domain transformation of the first current signal information collected by the first current transformer installed at the first acquisition location in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition location in the cable line to obtain the first current spectrum and the second current spectrum respectively further includes:

[0039] S1, the first current transformer and the second current transformer sample based on the target sampling rate to obtain the first current signal information and the second current signal information, wherein the target sampling rate is greater than the first sampling rate threshold.

[0040] S2, perform Fast Fourier Transform on the first current signal information and the second current signal information respectively to obtain the corresponding first current spectrum and second current spectrum.

[0041] As an optional implementation, in S1, the first current transformer and the second current transformer sample based on the target sampling rate to obtain the first current signal information and the second current signal information. The target sampling rate is greater than the first sampling rate threshold. The first sampling rate threshold is a minimum sampling frequency requirement. If the frequency is lower than this, the system may not be able to accurately capture the details of the changes in low-frequency harmonic current in the cable, thereby affecting the accuracy and sensitivity of fault detection.

[0042] For example, a first current transformer is installed at position T1 to collect the grounding current signal in the cable in real time at a target sampling rate (e.g., 10kHz) to obtain the first current signal information i_1(t); similarly, a second current transformer is installed at position T2 to collect the current signal in real time at the same target sampling rate of 10kHz to obtain the second current signal information i_2(t).

[0043] As an optional implementation, in S2, the first current signal information and the second current signal information are subjected to Fast Fourier Transform (FFT) respectively to obtain the corresponding first current spectrum and second current spectrum. The Fast Fourier Transform (FFT) is used to convert the time-domain signal into a frequency-domain signal, that is, to decompose the time-varying current signal into components of different frequencies. The first current spectrum and the second current spectrum are frequency domain representations of the signals obtained by FFT conversion, which are used to describe the intensity distribution of the grounding current in the cable at different frequencies.

[0044] For example, the time-domain signal i_1(t) obtained from the first current transformer is subjected to a Fast Fourier Transform (FFT) to obtain the first current spectrum I_1(f) in the frequency domain; similarly, the time-domain signal i_2(t) obtained from the second current transformer is also subjected to a Fast Fourier Transform (FFT) to obtain the second current spectrum I_2(f). In this process, the signal can be preprocessed appropriately, such as denoising or filtering, to improve the clarity and reliability of the FFT results.

[0045] The cable fault location method provided in this application uses a target sampling rate higher than the threshold for data acquisition, which greatly improves signal quality and reduces information distortion and analysis errors caused by insufficient sampling. The spectrum analysis can highlight specific frequency components related to potential cable faults, and then by comparing the first current spectrum and the second current spectrum, abnormal frequency components can be quickly located.

[0046] As an optional approach, after extracting the set of current amplitudes matching at least one target characteristic harmonic from the first current spectrum and the second current spectrum respectively, the method further includes:

[0047] S1, if the first current amplitude corresponding to the first acquisition position and the second current amplitude corresponding to the second acquisition position in the current amplitude set are both greater than the target threshold, it is determined that there is a fault in the cable line.

[0048] As an optional implementation, the current amplitude set in step S1 is a set of current amplitudes corresponding to the target characteristic harmonic frequency extracted from the first current spectrum and the second current spectrum; in the first current spectrum and the second current spectrum after frequency domain conversion, the current amplitudes corresponding to the target characteristic harmonic frequency (such as the 5th harmonic and the 7th harmonic) are extracted to form the current amplitude set.

[0049] Check the current amplitude set, including the first current amplitude (A_5-1), (A_7-1) corresponding to the first acquisition position, and the second current amplitude (A_5-2), (A_7-2) corresponding to the second acquisition position. If the current amplitude at both the first and second acquisition positions exceeds the preset target threshold, it is determined that there is a fault or abnormality in the cable line, and an early warning signal is issued.

[0050] The cable fault location method provided in this application adopts a two-point current amplitude comparison method, which avoids the accidental false alarms that may be caused by single-point measurement and ensures the robustness and accuracy of fault judgment.

[0051] As an optional approach, after extracting the current amplitude sets matching at least one target characteristic harmonic from the first current spectrum and the second current spectrum respectively, the method further includes:

[0052] S1, obtain a continuous subset of data points from the current amplitude set according to the initial filtering window;

[0053] S2, determine the average amplitude based on the value of each data point in the subset of data points;

[0054] S3, use the average amplitude as the value of the data point at the center of the initial filter window;

[0055] S4. Move the initial filter window back one sampling point and repeat the above process until the initial filter window covers the current amplitude set.

[0056] As an optional implementation, assuming a set of current amplitude values ​​({A_1,A_2,A_3...A_{100}}), and the filter window size is set to 5 points, the filter window is initialized as follows: initially, the subset of data points covered by the window is ({A_1,A_2,A_3,A_4,A_5}); the average amplitude is calculated: the average value of these five data points (V_{avg_1}) can be obtained by adding them together and dividing by 5; the center point value is updated: (V...) Assign the value of _{avg_1} to (A_3) (center point) to achieve smoothing; Move the window and repeat the steps: Move the window one point backward, so that the window now covers ({A_2,A_3,A_4,A_5,A_6}), recalculate the average value, update the value of (A_4), and repeat this operation until the window covers the last five data points ({A_{96},A_{97},A_{98},A_{99},A_{100}}).

[0057] The cable fault location method provided in this application smooths all current amplitude values, reduces the impact of random noise, and improves the accuracy and reliability of subsequent fault identification.

[0058] As an alternative approach, determining the location of a fault on a cable line based on the time difference and the signal propagation speed includes:

[0059] S1, when the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is positive, determine the first distance between the first acquisition position and the second acquisition position, and determine the fault location based on the first distance, time difference and propagation speed;

[0060] Understandably, when a signal is detected at the first acquisition location and then at the second acquisition location, and the signal arrival time difference is positive, the precise location of the fault point can be determined based on the known first distance between the two acquisition points, the signal time difference, and the signal propagation speed in the cable.

[0061] As an optional implementation, based on the physical layout of the cable line, a first distance (L) between the first acquisition position and the second acquisition position is preset. When the signal is detected at the first position (T_1) and the second position (T_2), the arrival time (t1) and (t2) of the signal are recorded to obtain the time difference Δt=t2-t1. The distance (d) from the fault point to the first acquisition position is calculated using the formula d=(L-Δt×v) / 2, where (v) is the propagation speed of the signal in the cable.

[0062] S2, when the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is negative, determine the reference acquisition position in the cable line, and determine the fault location based on the time when the signal reaches the first acquisition position, the second acquisition position, and the reference acquisition position.

[0063] It is understandable that when the time difference of the signal is negative, it means that the signal arrives at the second acquisition position first and then at the first acquisition position. An additional reference position and its time information are needed to help determine the precise location of the fault.

[0064] As an optional implementation, a reference acquisition position is preset in the cable line, such as the other end of the cable or the third intermediate joint position (T_3) in the line. The arrival times of the signal at the first acquisition position, the second acquisition position, and the reference acquisition position are determined. The time difference Δt1=t3-t1 between the arrival of the signal at (T1) and (T3) and the time difference Δt2=t3-t2 between the arrival of the signal at (T2) and (T3) are calculated. Using Δt1, Δt2, and the propagation speed (v), combined with the distance information between (T1), (T2), and (T3), the precise location of the fault point is determined by a triangulation algorithm, including but not limited to solving a set of equations using linear algebra methods or applying a specific positioning algorithm model.

[0065] As an alternative approach, determining the fault location based on a first distance, time difference, and propagation speed also includes:

[0066] S1, calculate the product of the time difference and the signal propagation speed to obtain the first parameter value;

[0067] S2, determine the distance between the fault location and the first acquisition location based on the difference between the first distance and the first parameter value.

[0068] The above steps S1-S2 will be described in an optional implementation. It is assumed that the fault point is located between T1 and T2, and the signal arrives at T1 first and then at T2, that is, the time difference Δt=t2-t1>0, the above first parameter value=v×Δt, and the above first distance is the distance between T1 and T2.

[0069] It is understandable that, assuming the fault point is located between T1 and T2, the distance to T1 is (d), that is, the straight-line distance of the signal from the fault point to T1 is (d), so the time required for the signal to travel from the fault point to T1 is d / v; the distance for the same signal to travel from the fault point to T2 is (Ld), so the time required for the signal to travel from the fault point to T2 is (Ld) / v, the time difference Δt=(Ld) / vd / v=(L-2d) / v, then d=(L-Δt×v) / 2.

[0070] The cable fault location method provided in this application achieves precise geometric location of the fault point by accurately calculating the time difference and utilizing known signal propagation speed and distance. It no longer relies on fuzzy signal strength comparison or rough cable segmentation search, but directly calculates the straight-line distance from the fault point to the monitoring point, thus improving the accuracy of fault point location.

[0071] As an optional approach, the fault location is determined based on the time it takes for the signal to arrive at the first acquisition position, the second acquisition position, and the reference acquisition position, including:

[0072] S1, determine the time sequence of the signals arriving at the first acquisition position, the second acquisition position, and the reference acquisition position;

[0073] S2, determine the first time difference and the second time difference according to the time sequence;

[0074] S3. Determine the fault location based on the first time difference, the second time difference, and the signal propagation speed.

[0075] Optionally, the above time sequence refers to the order in which the signal arrives at the three different locations; for example, if the signal arrives at the first acquisition location first, then the first time difference could be t2-t1, and the second time difference could be t3-t1.

[0076] The above steps S1-S3 will be described using a complete implementation method:

[0077] Select a reference location in the cable line as the reference acquisition point, such as the third intermediate joint location (T3); if the signal arrives at the first acquisition location (T1) first, determine the first time difference Δt31 = t3 - t1 > 0 between the time the signal arrives at (T3) and the time the signal arrives at (T1), and the second time difference Δt21 = t2 - t1 > 0 between the time the signal arrives at (T2) and the time the signal arrives at (T1).

[0078] Assuming the speed of signal propagation in the cable is (v), and the straight-line distance between (T1) and (T3) is (L_13), the distance of the signal from the fault point to (T1) can be expressed as (d1), and the distance from the fault point to (T3) is (d3).

[0079] Based on Δt31=t3-t1, the distance difference d31=v×Δt31 between the signal from the fault point to (T3) and (T1) can be calculated.

[0080] Similarly, the distance difference from (T1) to (T2) is d21=v×Δt21.

[0081] At points (T1), (T2), and (T3), draw circles with radii d1, d2=d1+d21, and d3=d1+d31 respectively. Theoretically, these three circles should intersect at one or two points, one of which is the fault point.

[0082] The cable fault location method provided in this application embodiment can construct a three-dimensional location framework using three acquisition points. By utilizing the time difference of signals arriving at different points, geometric calculations or mathematical models can be used to more accurately determine the spatial location of the fault point.

[0083] The following describes this solution using a complete embodiment, such as... Figure 2 As shown:

[0084] S202, Grounding Current Acquisition: Real-time acquisition of grounding current signals at at least two intermediate joints in the cable line using a low-frequency current transformer.

[0085] Specifically, for example, low-frequency current transformers (measurement frequency range 0~1kHz, accuracy ±1%) are installed at two adjacent intermediate joints of a cable line, denoted as transformers T1 and T2, and the straight-line distance between them along the cable line is L (unit: m).

[0086] The current transformer acquires the grounding current signal in real time at a sampling frequency of not less than 10kHz, and obtains the time-domain current sequence i1(t) (acquired at T1) and i2(t) (acquired at T2), and transmits it to the data processing unit.

[0087] S204, Harmonic Feature Extraction: Perform Fourier transform on the grounding current signal to extract the current amplitude of characteristic harmonics.

[0088] Specifically, the data processing unit performs Fast Fourier Transform (FFT) on i1(t) and i2(t) respectively to obtain the frequency domain current spectra I1(f) and I2(f); extracts the current amplitudes A5-1 and A5-2 (corresponding to T1 and T2 respectively) corresponding to the 5th harmonic (5f0, f0 is the fundamental frequency of the power grid 50Hz) from the spectrum, and the current amplitudes A7-1 and A7-2 corresponding to the 7th harmonic (7f0); and performs smoothing filtering on the extracted harmonic amplitudes to eliminate high-frequency noise interference, with the filtering window size set to 5 sampling points.

[0089] S206, Fault Warning Judgment: Compare the extracted harmonic current amplitude with the preset threshold to determine whether there is a potential fault in the cable.

[0090] Specifically, this includes setting a fault warning threshold of 1000A; if A5-1≥1000A and A5-2≥1000A, or A7-1≥1000A and A7-2≥1000A, then the cable line is determined to have a potential fault; otherwise, return to step S202 to continue monitoring.

[0091] S208, Fault Location: When a potential fault is determined, the location of the fault point is calculated by using the time difference of the characteristic harmonic signals collected by the two sets of intermediate connectors.

[0092] Select the characteristic harmonic that triggers the warning in step S206 (if the 5th harmonic exceeds the standard, the 5th harmonic is used as the reference; if the 7th harmonic exceeds the standard, the 7th harmonic is used as the reference), and determine the time difference Δt (unit: s) between the arrival of the harmonic signal at T1 and T2. Δt is calculated by the time difference between the peak values ​​of the signals collected by the two current transformers.

[0093] Based on the propagation speed v of the harmonic in the cable (unit: m / s, v is calculated from the cable medium parameters, generally taken as 1.5×10^8~2×10^8 m / s), the distance d between the fault point and T1 is calculated as d=(L-Δt×v) / 2. It can be understood that if Δt is positive, it indicates that the fault point is located between T1 and T2; if Δt is negative, it indicates that the fault point is located outside T1, and another sampling point needs to be designed to determine the specific fault location.

[0094] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0095] This application also provides a cable fault location locating device. It should be noted that the cable fault location locating device of this application can be used to execute the cable fault location locating method provided in this application. The cable fault location locating device provided in this application is described below.

[0096] Figure 3 This is a schematic diagram of a cable fault location locating device according to an embodiment of this application. Figure 3 As shown, the device includes:

[0097] The current acquisition module 302 performs frequency domain conversion on the first current signal information acquired by the first current transformer installed at the first acquisition position in the cable line and the second current signal information acquired by the second current transformer installed at the second acquisition position in the cable line to obtain the first current spectrum and the second current spectrum, respectively. The first acquisition position and the second acquisition position are two adjacent joint positions on the cable line. The measurement frequencies of the first current transformer and the second current transformer meet the low frequency response requirements. The first current signal information and the second current signal information are used to indicate the change in current intensity.

[0098] The signal processing module 304 extracts sets of current amplitudes that match at least one target characteristic harmonic from the first current spectrum and the second current spectrum, respectively, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency.

[0099] The time difference positioning module 306 determines the time difference between the arrival of the signal under the target characteristic harmonic at the first acquisition position and the arrival at the second acquisition position when there is a target current amplitude greater than the target threshold in the current amplitude set.

[0100] The fault location module 308 determines the location of the fault on the cable line based on the time difference and the speed of signal propagation.

[0101] Optionally, the current acquisition module 302 is further configured to sample the first current transformer and the second current transformer based on a target sampling rate to obtain first current signal information and second current signal information, wherein the target sampling rate is greater than a first sampling rate threshold; and to perform fast Fourier transform on the first current signal information and the second current signal information respectively to obtain their respective first current spectrum and second current spectrum.

[0102] Optionally, the signal processing module includes: a first determining unit, used to determine that there is a fault in the cable line when the first current amplitude corresponding to the first acquisition position and the second current amplitude corresponding to the second acquisition position in the current amplitude set are both greater than a target threshold.

[0103] Optionally, the signal processing module 304 is further configured to obtain a continuous subset of data points from the current amplitude set according to the initial filtering window; determine the average amplitude according to the value of each data point in the subset of data points; use the average amplitude as the value of the data point at the center position of the initial filtering window; move the initial filtering window backward by one sampling point, and repeat the above process until the initial filtering window covers the current amplitude set.

[0104] Optionally, the fault location module 308 includes: a second determining unit, configured to: determine a first distance between the first acquisition position and the second acquisition position when the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is positive; and determine the fault location based on the first distance, the time difference, and the propagation speed; and determine a reference acquisition position in the cable line when the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is negative; and determine the fault location based on the time when the signal reaches the first acquisition position, the second acquisition position, and the reference acquisition position.

[0105] Optionally, the second determining unit includes: a third determining subunit, used to calculate the product of the time difference and the signal propagation speed to obtain a first parameter value; and to determine the distance between the fault location and the first acquisition location based on the difference between the first distance and the first parameter value.

[0106] Optionally, the second determining unit further includes: a fourth determining subunit, used to determine the time sequence of the signal arriving at the first acquisition position, the second acquisition position, and the reference acquisition position; determine the first time difference and the second time difference according to the time sequence; and determine the fault location based on the first time difference, the second time difference, and the signal propagation speed.

[0107] Optionally, in this embodiment, the implementation of each of the above-mentioned unit modules can be referred to the above-mentioned method embodiments, which will not be repeated here.

[0108] The cable fault location device provided in this application includes a current acquisition module that performs frequency domain conversion on the first current signal information acquired by a first current transformer installed at a first acquisition position in the cable line and the second current signal information acquired by a second current transformer installed at a second acquisition position in the cable line to obtain a first current spectrum and a second current spectrum, respectively. The first and second acquisition positions are two adjacent joint positions on the cable line. The measurement frequencies of the first and second current transformers meet low-frequency response requirements. The first and second current signal information are used to indicate changes in current intensity. A signal processing module extracts a set of current amplitude values ​​matching at least one target characteristic harmonic from the first and second current spectra, respectively. The frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency. A time difference location module determines the time difference between the arrival of the signal under the target characteristic harmonic at the first acquisition position and the arrival at the second acquisition position when a target current amplitude value greater than a target threshold exists in the current amplitude set. A fault location module determines the fault location on the cable line based on the time difference and the signal propagation speed.

[0109] The aforementioned cable fault location locating device includes a processor and a memory. The aforementioned current acquisition module, signal processing module, time difference location module, and fault location module are all stored as program units in the memory. The processor executes the aforementioned program units stored in the memory to achieve the corresponding functions.

[0110] A processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and adjusting kernel parameters can improve the efficiency of modifying and refining programs.

[0111] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0112] This invention provides a computer-readable storage medium storing a program that, when executed by a processor, implements a method for locating cable faults.

[0113] This invention provides a processor for running a program, wherein the program executes a method for locating the location of a cable fault.

[0114] This application also provides an electronic device for implementing the above-described cable fault location method. This electronic device can be, for example, as follows: Figure 4 The terminal device or server shown is illustrated in this embodiment. This example uses this electronic device for illustration. Figure 4As shown, the electronic device includes a memory 402 and a processor 404. The memory 402 stores a computer program, and the memory 402 may include, but is not limited to, the current acquisition module 302, signal processing module 304, time difference positioning module 306, and fault positioning module 308 in the cable fault location positioning device described above. The processor 404 is configured to execute the cable fault location positioning method described above through the computer program. When the processor 404 executes the program, it performs the following steps:

[0115] The first current signal information collected by the first current transformer installed at the first acquisition position in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition position in the cable line are respectively frequency domain transformed to obtain the first current spectrum and the second current spectrum. The first acquisition position and the second acquisition position are two adjacent joint positions on the cable line. The measurement frequencies of the first current transformer and the second current transformer meet the low frequency response requirements. The first current signal information and the second current signal information are used to indicate the change of current intensity. The current amplitude set matching at least one target characteristic harmonic is extracted from the first current spectrum and the second current spectrum, respectively. The frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency. If there is a target current amplitude greater than the target threshold in the current amplitude set, the time difference between the signal under the target characteristic harmonic reaching the first acquisition position and reaching the second acquisition position is determined. Based on the time difference and the signal propagation speed, the fault location on the cable line is determined.

[0116] The first current transformer and the second current transformer sample based on the target sampling rate to obtain the first current signal information and the second current signal information, wherein the target sampling rate is greater than the first sampling rate threshold; the first current signal information and the second current signal information are respectively subjected to fast Fourier transform to obtain their respective first current spectrum and second current spectrum.

[0117] If the first current amplitude corresponding to the first acquisition position and the second current amplitude corresponding to the second acquisition position in the current amplitude set are both greater than the target threshold, it is determined that there is a fault in the cable line.

[0118] Obtain a continuous subset of data points from the current amplitude set based on the initial filtering window; determine the average amplitude based on the value of each data point in the subset; use the average amplitude as the value of the data point at the center of the initial filtering window; move the initial filtering window back one sampling point, and repeat the above process until the initial filtering window covers the current amplitude set.

[0119] If the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is positive, determine the first distance between the first acquisition position and the second acquisition position, and determine the fault location based on the first distance, the time difference, and the propagation speed. If the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is negative, determine the reference acquisition position in the cable line, and determine the fault location based on the time when the signal arrives at the first acquisition position, the second acquisition position, and the reference acquisition position.

[0120] The first parameter value is obtained by multiplying the time difference by the signal propagation speed; the distance between the fault location and the first acquisition location is determined based on the difference between the first distance and the first parameter value.

[0121] Determine the time sequence of the signal arrival at the first acquisition position, the second acquisition position, and the reference acquisition position; determine the first time difference and the second time difference according to the time sequence; determine the fault location based on the first time difference, the second time difference, and the signal propagation speed.

[0122] The devices mentioned in this article can be servers, PCs, tablets, mobile phones, etc.

[0123] This application also provides a computer program product that, when executed on a data processing device, is adapted to perform the method steps in this application;

[0124] Alternatively, as those skilled in the art will understand, Figure 4 The structure shown is for illustrative purposes only. Electronic devices can also be smartphones, tablets, handheld computers, mobile internet devices (MIDs), PADs, and other terminal devices. Figure 4 This does not limit the structure of the aforementioned electronic devices. For example, the electronic device may also include components that are more... Figure 4 The more or fewer components shown (such as network interfaces, etc.), or having the same Figure 4 The different configurations shown.

[0125] The memory 402 can be used to store software programs and modules, such as the program instructions / modules corresponding to the cable fault location method and device in this embodiment. The processor 404 executes various functional applications and data processing by running the software programs and modules stored in the memory 402, thereby realizing the aforementioned cable fault location method. The memory 402 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 402 may further include memory remotely located relative to the processor 404, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. Specifically, the memory 402 may be used, but is not limited to, to store information such as circuit status.

[0126] Optionally, the aforementioned electronic device further includes a transmission device 406, which is used to receive or send data via a network. Specific examples of the network may include wired and wireless networks. In one example, the transmission device 406 includes a Network Interface Controller (NIC), which can be connected to other network devices and a router via a network cable to communicate with the Internet or a local area network. In another example, the transmission device 406 is a radio frequency (RF) module used to communicate wirelessly with the Internet.

[0127] In addition, the aforementioned electronic device also includes: a display 408 for displaying the aforementioned information; and a connection bus 410 for connecting the various module components in the aforementioned electronic device.

[0128] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0129] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0130] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0131] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0132] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0133] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0134] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0135] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0136] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0137] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for locating the position of a cable fault, characterized in that, include: The first current signal information collected by the first current transformer installed at the first acquisition position in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition position in the cable line are respectively frequency domain transformed to obtain the first current spectrum and the second current spectrum. The first acquisition position and the second acquisition position are two adjacent joint positions on the cable line. The measurement frequencies of the first current transformer and the second current transformer meet the low frequency response requirements. The first current signal information and the second current signal information are used to indicate the change of current intensity. Extract sets of current amplitudes that match at least one target characteristic harmonic from the first current spectrum and the second current spectrum, respectively, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency; If there is a target current amplitude greater than the target threshold in the set of current amplitudes, determine the time difference between the arrival of the target characteristic harmonic signal at the first acquisition position and the arrival at the second acquisition position. The location of the fault on the cable line is determined based on the time difference and the propagation speed of the signal.

2. The method according to claim 1, characterized in that, The method further includes performing frequency domain transformation on the first current signal information collected by the first current transformer installed at the first acquisition location in the cable line and the second current signal information collected by the second current transformer installed at the second acquisition location in the cable line to obtain the first current spectrum and the second current spectrum, respectively. The first current transformer and the second current transformer sample based on a target sampling rate to obtain the first current signal information and the second current signal information, wherein the target sampling rate is greater than a first sampling rate threshold; Perform Fast Fourier Transform on the first current signal information and the second current signal information respectively to obtain the corresponding first current spectrum and second current spectrum.

3. The method according to claim 2, characterized in that, After extracting the sets of current amplitudes matching at least one target characteristic harmonic from the first current spectrum and the second current spectrum respectively, the method further includes: If both the first current amplitude corresponding to the first acquisition location and the second current amplitude corresponding to the second acquisition location in the current amplitude set are greater than the target threshold, it is determined that there is a fault in the cable line.

4. The method according to claim 2, characterized in that, After extracting the sets of current amplitudes matching at least one target characteristic harmonic from the first current spectrum and the second current spectrum respectively, the method further includes: A continuous subset of data points is obtained from the current amplitude set according to the initial filtering window; The average amplitude is determined based on the value of each data point in the subset of data points; The average amplitude is used as the value of the data point at the center position of the initial filter window; The initial filtering window is moved back by one sampling point, and the above process is repeated until the initial filtering window covers the current amplitude set.

5. The method according to claim 1, characterized in that, Determining the location of the fault on the cable line based on the time difference and the propagation speed of the signal includes: If the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is positive, a first distance between the first acquisition position and the second acquisition position is determined, and the fault location is determined based on the first distance, the time difference and the propagation speed. If the time difference between the first moment when the signal reaches the first acquisition position and the second moment when the signal reaches the second acquisition position is negative, a reference acquisition position in the cable line is determined, and the fault location is determined based on the time when the signal arrives at the first acquisition position, the second acquisition position, and the reference acquisition position.

6. The method according to claim 5, characterized in that, The step of determining the fault location based on the first distance, the time difference, and the propagation speed further includes: The first parameter value is obtained by multiplying the time difference by the propagation speed of the signal. The distance between the fault location and the first acquisition location is determined based on the difference between the first distance and the first parameter value.

7. The method according to claim 5, characterized in that, Determining the fault location based on the time it takes for the signal to arrive at the first acquisition location, the second acquisition location, and the reference acquisition location includes: Determine the time sequence in which the signal arrives at the first acquisition position, the second acquisition position, and the reference acquisition position; The first time difference and the second time difference are determined according to the stated time sequence. The fault location is determined based on the first time difference, the second time difference, and the propagation speed of the signal.

8. A positioning device based on the location of a cable fault, characterized in that, include: The current acquisition module performs frequency domain conversion on the first current signal information acquired by the first current transformer installed at the first acquisition position in the cable line and the second current signal information acquired by the second current transformer installed at the second acquisition position in the cable line to obtain the first current spectrum and the second current spectrum, respectively. The first acquisition position and the second acquisition position are two adjacent joint positions on the cable line. The measurement frequencies of the first current transformer and the second current transformer meet the low frequency response requirements. The first current signal information and the second current signal information are used to indicate the change in current intensity. The signal processing module extracts sets of current amplitudes that match at least one target characteristic harmonic from the first current spectrum and the second current spectrum, respectively, wherein the frequency of the target characteristic harmonic is an integer multiple of the fundamental frequency; The time difference positioning module determines the time difference between the arrival of the target characteristic harmonic signal at the first acquisition position and the arrival at the second acquisition position when there is a target current amplitude greater than the target threshold in the current amplitude set. The fault location module determines the location of the fault on the cable line based on the time difference and the propagation speed of the signal.

9. A processor, characterized in that, The processor is used to run a program, wherein the program executes the method according to any one of claims 1 to 7 when it runs.

10. An electronic device, characterized in that, The method includes one or more processors and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the method of any one of claims 1 to 7.

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