A cable fault detection method and detection system

Abstract

The invention discloses a cable fault detection method and a detection system, and relates to the technical field of fault detection. The invention comprises basic fault detection, basic fault positioning, position data analysis, precise fault positioning and precise fault identification. First, a cable is detected by a cable fault tester to determine whether a fault exists. Secondly, waveform data of the tester is collected and analyzed to obtain an initial fault detection position and a fault type. Then, according to the fault type, different methods are used to collect fault data and analyze to obtain a retest fault position. Then, the initial detection position, retest position and final detection position are analyzed to determine the precise fault position. Finally, a fault collection scheme is set according to the fault type and position, and fault data is collected and analyzed to determine the specific type of the fault. The invention obtains the precise position of the cable fault by analyzing the three types of position data, thereby improving the accuracy of the cable fault data analysis result.

Description

Technical Field

[0001] The present invention relates to the field of automation control technology, and in particular to a cable fault detection method and a detection system. Background Art

[0002] With the acceleration of urbanization, the scale of urban power grids continues to expand. As an important part of urban power grids, the safe and stable operation of cables is directly related to the quality of life of urban residents and the normal operation of cities. Cable failures will not only cause power supply interruptions, affecting the daily lives of residents and the production activities of enterprises, but may also cause safety accidents, resulting in economic losses and even casualties. Therefore, timely and accurate detection and positioning of cable faults are crucial to ensuring the continuity and reliability of urban power supply.

[0003] Prior art, such as the invention patent application with announcement number CN116519716A, discloses a cable fault detection method, which relates to the field of cable fault detection technology, including determining a division rule based on basic information of the cable to be detected, establishing a cable detection model according to the division rule; establishing an environmental impact model according to basic environmental information; constructing an original cable space model based on the cable detection model and the environmental impact model, connecting a transmitter and a receiver at both ends of the cable to be detected in a first direction, and obtaining a first cable space model; determining a plurality of first reflection signal information corresponding to the microwave signal based on the first cable space model; connecting a transmitter and a receiver at both ends of the cable to be detected in a second direction, and adjusting the original cable space model according to the second direction to obtain a second cable space model; determining the fault point information of the cable to be detected according to the first fault point information and the second fault point information. The accuracy of fault point detection is improved, and the reliability of detection is guaranteed, thereby improving the stability of safe operation of the cable.

[0004] With respect to the above scheme, the applicant of the present invention has found that the above scheme only measures the position of the fault point through microwave signals, and the microwave signals may be affected by other waves such as sound waves and electromagnetic waves, resulting in a decrease in the accuracy of the analysis results. The above scheme does not verify the analysis results of the microwave signals through other detection means, and the accuracy of the microwave signal data cannot be verified. At the same time, the above scheme confirms the information of a section of faulty cable through microwave signals at both ends of the fault point. The microwave signals use the same collection means, and do not combine and analyze multiple fault sections using multiple collection means, which reduces the accuracy of the analysis results. Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, an object of the present invention is to provide a cable fault detection method and a detection system.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a cable fault detection method, comprising the following steps: Step 1, basic fault detection: Use a cable fault tester to detect the cable to determine whether there is a fault.

[0007] Step 2: Basic fault location: When a fault occurs, collect the waveform data of the tester, and then analyze the waveform data of the tester to obtain the initial fault location and fault type. The fault type is divided into high-resistance fault and low-resistance fault.

[0008] Step 3: Position data analysis: When the fault type is a high-resistance fault, the high-resistance fault data is collected through the pulse reflection method, and the high-resistance fault data is analyzed to obtain the fault re-test position. When the fault type is a low-resistance fault, the low-resistance fault data is collected through the bridge method, and the low-resistance fault data is analyzed to obtain the fault re-test position.

[0009] Step 4. Accurately locate the fault: Analyze the initial measurement position and remeasurement position of the fault to obtain the remeasurement offset index. If the remeasurement offset index is less than or equal to the preset remeasurement offset index, the remeasurement position of the fault is recorded as the precise fault position. If the remeasurement offset index is greater than the preset remeasurement offset index, the final measurement position of the fault is obtained through the time domain reflection method. Based on the initial measurement position and remeasurement position of the fault, the final measurement position of the fault is analyzed to obtain the final measurement offset index and the initial measurement offset index, thereby determining the precise fault position.

[0010] Step 5: Accurately identify faults: According to the fault type and location, set up a fault collection plan, collect fault data, analyze the fault data, obtain the specific type of fault, and prompt the staff.

[0011] Preferably, the waveform data of the tester is analyzed, and the specific analysis process is as follows: the waveform data of the tester includes the starting fluctuation point distance, the fluctuation stable point distance and the fluctuation shape of the wavelet function image, the cable position where the tester is located is obtained from the database, the length of the starting fluctuation point distance of the cable position where the tester is located is extended in the current direction, and the position of the starting point of the cable fault initial measurement is obtained, the length of the fluctuation stable point distance of the cable position where the tester is located is extended in the current direction, and the position of the end point of the cable fault initial measurement is obtained. The cable fault initial measurement position is the cable position from the starting point to the end point of the cable fault initial measurement.

[0012] The fluctuation shape of the wavelet function image is divided into convex and concave. If the fluctuation shape of the wavelet function image is convex, the cable fault type is a high-resistance fault. If the fluctuation shape of the wavelet function image is concave, the cable fault type is a low-resistance fault.

[0013] Preferably, the initial measurement position and the re-measurement position of the fault are analyzed, and the specific analysis process is as follows: each reference point is set to obtain the position of each reference point, and the distances from each reference point position to the initial measurement position of the fault and the distances to the re-measurement position of the fault are obtained according to the initial measurement position and the re-measurement position of the fault, and the shortest distances from each reference point position to the initial measurement position of the fault and the shortest distances to the re-measurement position of the fault are substituted into the deviation index calculation formula The retest offset index is obtained , and are the shortest distances from the reference point a to the initial measurement position of the fault and the shortest distances to the re-measurement position of the fault, respectively. a is the number of each reference point. , , h is the preset standard deviation rate of initial measurement-retest, is the first weight factor of the preset reference point a, , .

[0014] Preferably, the final measured position of the fault is analyzed, and the specific analysis process is as follows: according to the final measured position of the fault, the distances from each reference point position to the final measured position of the fault are obtained, and the shortest distances from each reference point position to the final measured position of the fault are substituted into the final measured deviation index calculation formula: The final measured deviation index is obtained , is the shortest distance from the reference point a to the final measurement position of the fault, i is the preset standard deviation rate of final measurement-re-measurement, is the second weight factor of the preset reference point a, , .

[0015] Substitute the distance from each reference point to the final measurement position of the fault into the calculation formula of the initial measurement deviation index The initial measured deviation index is obtained , i is the preset standard deviation rate of final measurement - initial measurement, is the third weight factor of the preset reference point a, , .

[0016] Preferably, the specific judgment process of determining the fault location is as follows: if the final measurement offset index is less than or equal to the preset final measurement offset index, the final measurement location of the fault is recorded as the precise fault location; if the final measurement offset index is greater than the preset final measurement offset index and the initial measurement offset index is less than or equal to the preset initial measurement offset index, the re-measured location of the fault is recorded as the precise fault location; if the final measurement offset index is greater than the preset final measurement offset index and the initial measurement offset index is greater than the preset initial measurement offset index, the final measurement location of the fault is recorded as the precise fault location, thereby obtaining the precise fault location.

[0017] On the other hand, the present invention provides a cable fault detection system, comprising the following modules: a basic fault detection module, used to detect the cable using a cable fault tester to determine whether a fault exists.

[0018] The basic fault positioning module is used to collect the waveform data of the tester when a fault occurs, and then analyze the waveform data of the tester to obtain the initial fault location and fault type. The fault type is divided into high-resistance fault and low-resistance fault.

[0019] The position data analysis module is used to collect high-resistance fault data through the pulse reflection method when the fault type is a high-resistance fault, analyze the high-resistance fault data, and obtain the fault retest position; when the fault type is a low-resistance fault, it is used to collect low-resistance fault data through the bridge method, analyze the low-resistance fault data, and obtain the fault retest position.

[0020] The fault precise positioning module is used to analyze the initial measurement position and the remeasurement position of the fault to obtain the remeasurement offset index. If the remeasurement offset index is less than or equal to the preset remeasurement offset index, the remeasurement position of the fault is recorded as the precise fault position. If the remeasurement offset index is greater than the preset remeasurement offset index, the final measurement position of the fault is obtained by the time domain reflection method. Therefore, according to the initial measurement position and the remeasurement position of the fault, the final measurement position of the fault is analyzed to obtain the final measurement offset index and the initial measurement offset index, and then the precise fault position is determined.

[0021] The fault accurate identification module is used to set up the fault collection plan according to the fault type and location, collect fault data, analyze the fault data, obtain the specific type of fault, and prompt the staff.

[0022] The beneficial effects of the present invention are as follows: the present invention determines whether there is a fault in the cable through a tester, converts the tester data into a wavelet function when a fault occurs, collects waveform data through the function image of the wavelet function, and analyzes the waveform data to obtain the basic position of the cable fault and the basic type of the cable, selects different retest acquisition schemes according to the basic type of the cable, analyzes and obtains the retest position of the fault, and determines the precise position of the fault through the basic position and the retest position of the fault. If it cannot be determined, the final measurement position of the fault is obtained through the time domain reflection method, and the precise position of the fault is determined through the final measurement position of the fault. The present invention determines the precise position of the fault through three positions, thereby improving the accuracy and efficiency of fault detection, helping to repair cable faults in a timely manner, and ensuring the stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative work.

[0024] Figure 1 It is a schematic flow chart of the steps for implementing the method of the present invention;

[0025] Figure 2 It is a schematic diagram of the system structure connection of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0027] according to Figure 1 As shown, the present invention provides a cable fault detection method, comprising the following steps:

[0028] Step 1: Basic fault detection: Use a cable fault tester to detect the cable to determine whether there is a fault.

[0029] It should be noted that the cable fault tester is a voltage, current and electromagnetic intensity detector. Secondly, the detection is regular detection or active detection by staff.

[0030] In a specific embodiment, the judgment of whether there is a fault is specifically made as follows: signal data is collected through a cable fault tester, the cable signal data including the cable voltage, cable current and cable electromagnetic wave intensity within a preset time period, and each voltage, current and electromagnetic wave intensity at the time of the fault is obtained from a database. If the cable voltage is equal to a certain voltage at the time of the fault, the cable current is equal to a certain current at the time of the fault, or the cable electromagnetic wave intensity is equal to a certain electromagnetic wave intensity at the time of the fault, it indicates that a cable detection fault has occurred, and the fault duration of the cable in the preset time period is obtained by statistics. The maximum fault duration of the preset time period in the database when normal is selected and recorded as the standard fault duration of the preset time period. If the fault duration of the cable in the expected time period is greater than the standard fault duration of the preset time period, it indicates that the cable has a fault.

[0031] Step 2: Basic fault location: When a fault occurs, collect the waveform data of the tester, and then analyze the waveform data of the tester to obtain the initial fault location and fault type. The fault type is divided into high-resistance fault and low-resistance fault.

[0032] In a specific embodiment, the waveform data of the tester is collected, and the specific collection process is as follows: the voltage, current and electromagnetic wave intensity data of the cable are subjected to wavelet transformation to obtain the wavelet function of the cable, and then a function image of the wavelet function of the cable is made, and the waveform data of the tester is extracted from the function image of the wavelet function of the cable.

[0033] In a specific embodiment, the waveform data of the tester is analyzed, and the specific analysis process is as follows: the waveform data of the tester includes the starting fluctuation point distance, the fluctuation stable point distance and the fluctuation shape of the wavelet function image, the cable position where the tester is located is obtained from the database, the cable position where the tester is located is extended to the length of the starting fluctuation point distance in the current direction, and the position of the cable fault initial measurement starting point is obtained, the cable position where the tester is located is extended to the length of the fluctuation stable point distance in the current direction, and the position of the cable fault initial measurement end point is obtained. The cable fault initial measurement position is the cable position from the cable fault initial measurement starting point to the initial measurement end point.

[0034] The fluctuation shape of the wavelet function image is divided into convex and concave. If the fluctuation shape of the wavelet function image is convex, the cable fault type is a high-resistance fault. If the fluctuation shape of the wavelet function image is concave, the cable fault type is a low-resistance fault.

[0035] Step 3: Position data analysis: When the fault type is a high-resistance fault, the high-resistance fault data is collected through the pulse reflection method, and the high-resistance fault data is analyzed to obtain the fault re-test position. When the fault type is a low-resistance fault, the low-resistance fault data is collected through the bridge method, and the low-resistance fault data is analyzed to obtain the fault re-test position.

[0036] In a specific embodiment, the high-resistance fault data is collected by the pulse reflection method, and the specific collection process is as follows: the pulse meters at both ends of the initial measurement position of the fault are selected to emit pulses, and the pulse signals are received at the same time to obtain the reflection time of the starting point of the fault section and the reflection time of the end point of the fault.

[0037] In a specific embodiment, the high-resistance fault data is analyzed, and the specific analysis process is as follows: the high-resistance fault data includes the reflection time length of the starting point of the fault section and the reflection time of the fault endpoint , substitute the reflection time of the starting point of the fault section into the calculation formula of the first pulse reflection distance The distance between the fault starting point and the pulse point is obtained , substitute the reflection time of the fault endpoint into the second pulse reflection distance calculation formula The distance between the fault end point and the pulse point is obtained , H is the distance between the pulse instruments at both ends, v is the pulse signal speed, and then according to the cable position of the pulse point in the database, the cable fault retest starting position and end position in the case of high resistance fault are obtained. The fault retest position in the case of high resistance fault is the cable position from the cable fault retest starting point to the final test end point.

[0038] In a specific embodiment, the low-resistance fault data is collected by the bridge method, and the specific collection process is as follows: the bridge meters at both ends of the initial fault measurement position are activated, and the impedance of the cables at the bridge meter positions at both ends are collected at the same time to obtain the fault section starting impedance and fault section end impedance of the bridge at both ends.

[0039] In a specific embodiment, the low-resistance fault data is analyzed, and the specific analysis process is as follows: the low-resistance fault data includes the fault segment starting impedance and the fault segment end impedance of the two-end bridge. The low-resistance fault data is substituted into the first resistance abnormal distance formula The distance between the fault starting point and the bridge point is obtained , Substitute the low resistance fault data into the second resistance anomaly distance formula The distance between the fault end point and the bridge point is obtained , and are the fault section starting impedance and fault section ending impedance of the starting bridge respectively. and are the starting impedance and ending impedance of the fault section of the terminal bridge respectively, L is the distance between the bridge instruments at both ends in the database, and then according to the cable position of the bridge point in the database, the starting position and ending position of the cable fault remeasurement in the case of a low-resistance fault are obtained. The fault remeasurement position in the case of a low-resistance fault is the cable position from the starting point of the cable fault remeasurement to the final measurement end point.

[0040] Step 4. Accurately locate the fault: Analyze the initial measurement position and remeasurement position of the fault to obtain the remeasurement offset index. If the remeasurement offset index is less than or equal to the preset remeasurement offset index, the remeasurement position of the fault is recorded as the precise fault position. If the remeasurement offset index is greater than the preset remeasurement offset index, the final measurement position of the fault is obtained through the time domain reflection method. Based on the initial measurement position and remeasurement position of the fault, the final measurement position of the fault is analyzed to obtain the final measurement offset index and the initial measurement offset index, thereby determining the precise fault position.

[0041] In a specific embodiment, the initial measurement position and the re-measurement position of the fault are analyzed, and the specific analysis process is as follows: each reference point is set to obtain the position of each reference point, and the distances from each reference point position to the initial measurement position of the fault and the distances to the re-measurement position of the fault are obtained according to the initial measurement position and the re-measurement position of the fault, and the shortest distances from each reference point position to the initial measurement position of the fault and the shortest distances to the re-measurement position of the fault are substituted into the offset index calculation formula The retest offset index is obtained , and are the shortest distances from the reference point a to the initial measurement position of the fault and the shortest distances to the re-measurement position of the fault, respectively. a is the number of each reference point. , , h is the preset standard deviation rate of initial measurement-retest, is the first weight factor of the preset reference point a, , .

[0042] It should be noted that the reference point is the position of the collectors at both ends of the fault point. Generally, the two points of the cable where the first collector at the front end of the fault start point and the first collector at the back end of the fault end point are selected as the reference points. The maximum offset rate of the retest offset index of each accurate judgment in the database is selected as the standard offset rate of the initial measurement-retest, and the number of accurate judgments of the retest offset index of each reference point is selected. , .

[0043] In a specific embodiment, the final measured position of the fault is analyzed, and the specific analysis process is as follows: according to the final measured position of the fault, the distances from each reference point position to the final measured position of the fault are obtained, and the shortest distances from each reference point position to the final measured position of the fault are substituted into the final measured deviation index calculation formula The final measured deviation index is obtained , is the shortest distance from the reference point a to the final measurement position of the fault, i is the preset standard deviation rate of final measurement-re-measurement, is the second weight factor of the preset reference point a, , .

[0044] It should be noted that the maximum deviation rate of the final measurement deviation index of each accurate judgment is selected from the database as the standard deviation rate of the final measurement-re-measurement, and the number of accurate judgments of the final measurement deviation index of each benchmark point is selected. , .

[0045] Substitute the distance from each reference point to the final measurement position of the fault into the calculation formula of the initial measurement deviation index The initial measured deviation index is obtained , i is the preset standard deviation rate of final measurement - initial measurement, is the third weight factor of the preset reference point a, , .

[0046] It should be noted that the maximum deviation rate of the initial measurement deviation index of each accurate judgment selected from the database is the standard deviation rate of the final measurement minus the initial measurement, and the number of accurate judgments of the initial measurement deviation index of each reference point is selected. , .

[0047] In a specific embodiment, the fault location is determined by the following specific determination process: if the final measurement offset index is less than or equal to a preset final measurement offset index, the final measurement location of the fault is recorded as the precise fault location; if the final measurement offset index is greater than the preset final measurement offset index and the initial measurement offset index is less than or equal to the preset initial measurement offset index, the re-measured location of the fault is recorded as the precise fault location; if the final measurement offset index is greater than the preset final measurement offset index and the initial measurement offset index is greater than the preset initial measurement offset index, the final measurement location of the fault is recorded as the precise fault location, thereby obtaining the precise fault location.

[0048] Step 5: Accurately identify faults: According to the fault type and location, set up a fault collection plan, collect fault data, analyze the fault data, obtain the specific type of fault, and prompt the staff.

[0049] In a specific embodiment, the fault data is analyzed, and the specific analysis process is as follows: the fault data includes the cable fault location and the data of each cable fault collector, and the fault location of each specific type of fault and the data of each fault collector are obtained from the database. If the cable fault location is a certain fault location of a specific type of fault and the data of each cable fault collector are equal to certain data of each fault collector of the specific type of fault, it indicates that the cable fault is of the specific type of fault.

[0050] It should be noted that the specific fault type, fault location and required fault collector corresponding to each cable fault are obtained through the specific fault type and fault location, and then the required fault collectors for the cable fault are obtained. For example, if a fault is a line break, a drone is used to collect images.

[0051] according to Figure 2 As shown, the present invention provides a cable fault detection system, comprising the following modules: a basic fault detection module, a basic fault positioning module, a position data analysis module, a fault precise positioning module and a fault precise identification module.

[0052] The position data analysis module is connected to the basic fault detection module and the position data analysis module respectively, and the fault precise positioning module is connected to the position data analysis module and the fault precise identification module respectively.

[0053] The basic fault detection module is used to detect the cable using a cable fault tester to determine whether there is a fault when the cable is tested regularly or when the staff initiates preliminary testing.

[0054] The basic fault positioning module is used to collect the waveform data of the tester when a fault occurs, and then analyze the waveform data of the tester to obtain the initial fault location and fault type. The fault type is divided into high-resistance fault and low-resistance fault.

[0055] The position data analysis module is used to collect high-resistance fault data through the pulse reflection method when the fault type is a high-resistance fault, analyze the high-resistance fault data, and obtain the fault retest position; when the fault type is a low-resistance fault, it is used to collect low-resistance fault data through the bridge method, analyze the low-resistance fault data, and obtain the fault retest position.

[0056] The fault precise positioning module is used to analyze the initial measurement position and the remeasurement position of the fault to obtain the remeasurement offset index. If the remeasurement offset index is less than or equal to the preset remeasurement offset index, the remeasurement position of the fault is recorded as the precise fault position. If the remeasurement offset index is greater than the preset remeasurement offset index, the final measurement position of the fault is obtained by the time domain reflection method. Therefore, according to the initial measurement position and the remeasurement position of the fault, the final measurement position of the fault is analyzed to obtain the final measurement offset index and the initial measurement offset index, and then the precise fault position is determined.

[0057] The fault accurate identification module is used to set up the fault collection plan according to the fault type and location, collect fault data, analyze the fault data, obtain the specific type of fault, and prompt the staff.

[0058] The database is used to store various voltages at the time of fault, various currents at the time of fault, various electromagnetic wave intensities at the time of fault, the maximum fault duration in a preset time period under normal circumstances, the cable position of the tester, the cable position of the pulse point, the distance between the bridge instruments at both ends, the maximum offset rate of each accurately judged re-measurement offset index, the maximum offset rate of each accurately judged final measurement offset index, the maximum offset rate of each accurately judged initial measurement offset index, each fault location of each specific type of fault and each data of each fault collector of each specific type of fault.

[0059] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined in this specification, they shall all fall within the protection scope of the present invention.

Claims

1. A cable fault detection method, characterized in that: The steps include: Step 1: Basic fault detection: Use a cable fault tester to detect the cable to determine whether there is a fault; Step 2: Basic fault location: When a fault occurs, collect the waveform data of the tester, and then analyze the waveform data of the tester to obtain the initial fault location and fault type. The fault type is divided into high-resistance fault and low-resistance fault; Step 3: Position data analysis: When the fault type is a high-resistance fault, the high-resistance fault data is collected by the pulse reflection method, and the high-resistance fault data is analyzed to obtain the fault retest position. When the fault type is a low-resistance fault, the low-resistance fault data is collected by the bridge method, and the low-resistance fault data is analyzed to obtain the fault retest position. Step 4, accurate fault location: Analyze the initial measurement position and re-measurement position of the fault to obtain the re-measurement offset index. If the re-measurement offset index is less than or equal to the preset re-measurement offset index, the re-measurement position of the fault is recorded as the precise fault position. If the re-measurement offset index is greater than the preset re-measurement offset index, the final measurement position of the fault is obtained by time domain reflection method. According to the initial measurement position and re-measurement position of the fault, the final measurement position of the fault is analyzed to obtain the final measurement offset index and the initial measurement offset index, and then the precise fault position is determined. Step 5: Accurately identify faults: According to the fault type and location, set up a fault collection plan, collect fault data, analyze the fault data, obtain the specific type of fault, and prompt the staff; The waveform data of the tester is analyzed, and the specific analysis process is as follows: the waveform data of the tester includes the distance of the starting fluctuation point, the distance of the fluctuation stable point and the fluctuation shape of the wavelet function image, the cable position where the tester is located is obtained from the database, the length of the distance of the starting fluctuation point is extended in the current direction of the cable position where the tester is located, and the position of the starting point of the cable fault initial measurement is obtained, the length of the distance of the fluctuation stable point is extended in the current direction of the cable position where the tester is located, and the position of the end point of the cable fault initial measurement is obtained, and the cable fault initial measurement position is the cable position from the starting point of the cable fault initial measurement to the end point of the initial measurement; The fluctuation shape of the wavelet function image is divided into convex and concave. If the fluctuation shape of the wavelet function image is convex, the cable fault type is a high-resistance fault. If the fluctuation shape of the wavelet function image is concave, the cable fault type is a low-resistance fault. The initial measurement position and the re-measurement position of the fault are analyzed, and the specific analysis process is as follows: each reference point is set, and then the position of each reference point is obtained. According to the initial measurement position and the re-measurement position of the fault, each distance from each reference point position to the initial measurement position of the fault and each distance to the re-measurement position of the fault are obtained, and each shortest distance from each reference point position to the initial measurement position of the fault and each shortest distance to the re-measurement position of the fault are substituted into the offset index calculation formula The retest offset index is obtained , and are the shortest distances from the reference point a to the initial measurement position of the fault and the shortest distances to the re-measurement position of the fault, respectively. a is the number of each reference point. , , h is the preset standard deviation rate of initial measurement-retest, is the first weight factor of the preset reference point a, , ; The final measurement position of the fault is analyzed, and the specific analysis process is as follows: according to the final measurement position of the fault, the distances from each reference point position to the final measurement position of the fault are obtained, and the shortest distances from each reference point position to the final measurement position of the fault are substituted into the final measurement deviation index calculation formula The final measured deviation index is obtained , is the shortest distance from the reference point a to the final measurement position of the fault, i is the preset standard deviation rate of final measurement-re-measurement, is the second weight factor of the preset reference point a, , ; Substitute the distance from each reference point to the final measurement position of the fault into the calculation formula of the initial measurement deviation index The initial measured deviation index is obtained , i is the preset standard deviation rate of final measurement - initial measurement, is the third weight factor of the preset reference point a, , ; The specific judgment process of determining the fault position is as follows: if the final measurement offset index is less than or equal to the preset final measurement offset index, the final measurement position of the fault is recorded as the precise fault position; if the final measurement offset index is greater than the preset final measurement offset index and the initial measurement offset index is less than or equal to the preset initial measurement offset index, the re-measured position of the fault is recorded as the precise fault position; if the final measurement offset index is greater than the preset final measurement offset index and the initial measurement offset index is greater than the preset initial measurement offset index, the final measurement position of the fault is recorded as the precise fault position, thereby obtaining the precise fault position.

2. A cable fault detection method according to claim 1, characterized in that: The specific process of judging whether there is a fault is as follows: Signal data is collected through a cable fault tester. The cable signal data includes the cable voltage, cable current and cable electromagnetic wave intensity within a preset time period. The voltages, currents and electromagnetic wave intensities at the time of the fault are obtained from the database. If the cable voltage is equal to a certain voltage at the time of the fault, the cable current is equal to a certain current at the time of the fault, or the cable electromagnetic wave intensity is equal to a certain electromagnetic wave intensity at the time of the fault, it indicates that a cable detection fault has occurred. The fault duration of the cable in the preset time period is obtained by statistics. The maximum fault duration of the preset time period when normal in the database is selected and recorded as the standard fault duration of the preset time period. If the cable fault duration in the expected time period is greater than the standard fault duration of the preset time period, it indicates that the cable has a fault.

3. A cable fault detection method according to claim 1, characterized in that: The high resistance fault data is analyzed, and the specific analysis process is as follows: The high-resistance fault data includes the reflection time at the starting point of the fault section and the reflection time at the end point of the fault. The high-resistance fault data is substituted into the pulse reflection distance calculation formula to obtain the distance between the fault starting point and the pulse point and the distance between the fault end point and the pulse point. Then, according to the cable position of the pulse point in the database, the cable fault retest starting point and end point are obtained during the high-resistance fault. The fault retest position during the high-resistance fault is the cable position from the cable fault retest starting point to the retest end point.

4. A cable fault detection method according to claim 1, characterized in that: The low resistance fault data is analyzed, and the specific analysis process is as follows: The low-resistance fault data includes the impedance of the fault section starting point and the impedance of the fault section ending point of the bridge at both ends. The low-resistance fault data is substituted into the resistance anomaly distance formula to obtain the distance between the fault starting point and the bridge point and the distance between the fault ending point and the bridge point. Then, according to the cable position of the bridge point in the database, the cable fault retest starting point and end point are obtained during the low-resistance fault. The fault retest position during the low-resistance fault is the cable position from the cable fault retest starting point to the retest end point.

5. A cable fault detection method according to claim 1, characterized in that: The fault data is analyzed, and the specific analysis process is as follows: The fault data includes the cable fault location and the data of each cable fault collector. The fault location of each specific type of fault and the data of each fault collector are obtained from the database. If the cable fault location is a certain fault location of a specific type of fault and the data of each cable fault collector are equal to a certain data of each fault collector of the specific type of fault, it indicates that the cable fault is of the specific type of fault.

6. A cable fault detection system using the cable fault detection method according to any one of claims 1 to 5, characterized in that: Includes the following modules: A basic fault detection module is used to detect the cable using a cable fault tester to determine whether there is a fault; The basic fault location module is used to collect the waveform data of the tester when a fault occurs, and then analyze the waveform data of the tester to obtain the initial fault location and fault type. The fault type is divided into high-resistance fault and low-resistance fault; The position data analysis module is used to collect high-resistance fault data through the pulse reflection method when the fault type is a high-resistance fault, analyze the high-resistance fault data, and obtain the fault retest position; when the fault type is a low-resistance fault, collect low-resistance fault data through the bridge method, analyze the low-resistance fault data, and obtain the fault retest position; The fault precise positioning module is used to analyze the initial measurement position and the re-measurement position of the fault to obtain the re-measurement offset index. If the re-measurement offset index is less than or equal to the preset re-measurement offset index, the re-measurement position of the fault is recorded as the precise fault position. If the re-measurement offset index is greater than the preset re-measurement offset index, the final measurement position of the fault is obtained by the time domain reflection method. Thus, according to the initial measurement position and the re-measurement position of the fault, the final measurement position of the fault is analyzed to obtain the final measurement offset index and the initial measurement offset index, and then the precise fault position is determined. The fault accurate identification module is used to set up the fault collection plan according to the fault type and location, collect fault data, analyze the fault data, obtain the specific type of fault, and prompt the staff.

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