Power distribution cable defect detection method, device, system, equipment and medium based on current component characteristics

Abstract

The application relates to a power distribution cable defect detection method, device and system based on current component characteristics, computer equipment and a computer readable storage medium. The method comprises the following steps: acquiring a current phasor at a target position of a shielding layer of a cable and a grounding current at a detection position of the shielding layer; wherein the grounding current at the detection position is collected based on the position of a grounding current collection device; the current phasor is determined based on initial data collected by an eddy current collection device; the current phasor and the grounding current are collected at the same time; the detection position and the target position are different positions; the grounding current at the detection position of the shielding layer is phase compensated to obtain a grounding current component at the target position; the grounding current component at the target position in the current phasor at the target position of the shielding layer is eliminated to obtain an eddy current component; the eddy current component is subjected to cluster analysis, and defect information of the cable is determined according to an analysis result. The method can detect whether defects exist in a local part of the cable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detection, in particular to a power distribution cable defect detection method, device and system based on current component characteristics, computer equipment and computer readable storage medium. BACKGROUND

[0002] The proportion of cable lines in domestic urban power grids is increasing, and as the operating life increases, power distribution cable line faults also occur frequently. Since cables are mostly buried underground, it is very difficult to troubleshoot cable line faults. At present, there are a large number of technologies for cable defect diagnosis in order to detect cable faults in advance and eliminate hidden dangers. Cable defects generally produce sound, light, electricity, heat and other effects, and existing measurement technologies are based on these phenomena. For example, ultrasonic testing based on ultrasonic waves generated by defect discharge is weak and attenuated through the medium, so the sensitivity of this technology is not high. Temperature detection based on infrared still has the problem of low detection sensitivity. Since there is a metal shielding layer on the outer layer of the cable, the electric field generated by the defect is shielded and cannot be directly measured.

[0003] In traditional technologies, the current of the cable shielding layer or the grounding point is tested by a current sensor, and corresponding characteristic quantities are extracted to reflect the cable defect state.

[0004] However, the current cable defect detection method only evaluates the entire cable, reflects the aging or serious through defects of the entire cable, and is difficult to reflect or locate the local defects of the cable. SUMMARY

[0005] Therefore, it is necessary to provide a power distribution cable defect detection method, device, system, computer equipment and computer readable storage medium based on current component characteristics, which can detect whether there are defects in the local position of the cable.

[0006] In a first aspect, the present application provides a power distribution cable defect detection method based on current component characteristics, comprising:

[0007] Obtaining the current phasor at the target position of the shielding layer of the cable and the grounding current at the detection position of the shielding layer; wherein the grounding current at the detection position is collected based on the position of the grounding current collection device; the current phasor is determined based on the initial data collected by the eddy current collection device; the current phasor and the grounding current are collected at the same time; the detection position and the target position are different positions;

[0008] Phase compensation is performed on the grounding current at the detection position of the shielding layer to obtain the grounding current component at the target position;

[0009] eliminate the ground current component at the target position in the current phasor at the target position of the shielding layer to obtain an eddy current component;

[0010] perform cluster analysis on the eddy current component, and determine defect information of the cable according to an analysis result.

[0011] In one of the embodiments, the obtaining of the current phasor at the target position of the shielding layer of the cable comprises:

[0012] obtaining a proportional coefficient determined according to the current of the shielding layer and a magnetic field strength corresponding to the current;

[0013] obtaining a target magnetic field strength of the eddy current acquisition device at the target position of the shielding layer;

[0014] determining the current phasor at the target position of the shielding layer based on the proportional coefficient and the target magnetic field strength.

[0015] In one of the embodiments, the phase compensation of the ground current at the detection position of the shielding layer to obtain the ground current component at the target position comprises:

[0016] obtaining a phase shift constant and an electrical distance between the detection position and the target position;

[0017] determining the ground current component at the target position based on the ground current at the detection position of the shielding layer, the phase shift constant and the electrical distance between the detection position and the target position.

[0018] In one of the embodiments, the analysis result comprises abnormal data; and the determination of the defect information of the cable according to the analysis result comprises:

[0019] when the number of the abnormal data exceeds a defect number threshold, determining that the cable has defects;

[0020] obtaining reference defect information and an eddy current characteristic database;

[0021] determining the defect information of the cable according to the eddy current characteristic and the reference defect and eddy current characteristic database, wherein the defect information comprises a defect type and a degradation degree.

[0022] In a second aspect, the application provides a power distribution cable defect detection device based on current component characteristics, the device comprising:

[0023] The acquisition module is configured to acquire a current phasor at a target position of a shielding layer of a cable and a grounding current at a detection position of the shielding layer; the grounding current at the detection position is collected based on a position of the grounding current collection device; the current phasor is determined based on initial data collected by the eddy current collection device; the current phasor and the grounding current are collected at the same time; and the detection position and the target position are different positions.

[0024] The compensation module is configured to perform phase compensation on the grounding current at the detection position of the shielding layer to obtain a grounding current component at the target position.

[0025] The elimination module is configured to eliminate the grounding current component at the target position from the current phasor at the target position of the shielding layer to obtain an eddy current component.

[0026] The determination module is configured to perform clustering analysis on the eddy current component, and determine defect information of the cable according to an analysis result.

[0027] In a third aspect, the present application provides a power distribution cable defect detection system based on current component characteristics, which comprises: a power distribution cable defect detection device based on current component characteristics, an eddy current collection device, and a grounding current collection device; the eddy current collection device and the grounding current collection device are in communication connection with the power distribution cable defect detection device based on current component characteristics.

[0028] The eddy current collection device is configured to collect initial data at the target position of the shielding layer.

[0029] The grounding current collection device is configured to collect a grounding current at a detection position of a shielding layer, the detection position being a position of the grounding current collection device; the eddy current collection device and the grounding current collection device collect at the same time; and the detection position and the target position are different positions.

[0030] The power distribution cable defect detection device based on current component characteristics is configured to acquire a current phasor at a target position of a shielding layer of a cable and a grounding current at a detection position of the shielding layer; the grounding current at the detection position is collected based on a position of the grounding current collection device; the current phasor is determined based on initial data collected by the eddy current collection device; the current phasor and the grounding current are collected at the same time; and the detection position and the target position are different positions; the grounding current at the detection position of the shielding layer is phase compensated to obtain a grounding current component at the target position; the grounding current component at the target position is eliminated from the current phasor at the target position of the shielding layer to obtain an eddy current component; and the eddy current component is subjected to clustering analysis, and defect information of the cable is determined according to an analysis result.

[0031] In one embodiment, the eddy current acquisition device comprises:

[0032] A circular arc shell;

[0033] A magnetic sensor arranged inside the circular arc shell, configured to acquire initial data at a target position of the shielding layer, the initial data comprising magnetic field strength;

[0034] A pulley connected to a side of the sensor away from the inside of the circular arc shell, configured to move along the outer circumference of the cable or axially along the cable;

[0035] A first communication module in communication with the magnetic sensor, configured to transmit the current phasor to the power distribution cable defect detection device based on current component characteristics, and configured to receive acquisition time and defect information;

[0036] A first processor connected to the first communication module, configured to determine the current phasor according to the magnetic field strength;

[0037] A display module located outside the circular arc shell and connected to the first processor, configured to display the magnetic field strength and the defect information.

[0038] In one embodiment, the thickness of the circular arc shell is greater than or equal to 20 cm.

[0039] In a fourth aspect, the present application provides a computer device comprising a memory and a second processor, wherein the memory stores a computer program, and the second processor implements the steps of the above method when executing the computer program.

[0040] In a fifth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the above method when executed by a processor.

[0041] The power distribution cable defect detection method, device, system, computer equipment and computer readable storage medium based on current component characteristics provided by the application first acquire the current phasor at the target position of the shielding layer and the grounding current at the shielding layer detection position; the grounding current at the shielding layer detection position is compensated to obtain the grounding current component at the target position; the grounding current component at the target position in the current phasor at the target position of the shielding layer is eliminated to obtain the eddy current component; when a local defect occurs in the insulating layer of the cable, the magnetic flux in the local area changes, affecting the eddy current generated at the position, thereby causing the eddy current to be unbalanced, and the eddy current component appears in the external magnetic field; finally, the eddy current component is subjected to cluster analysis to determine the information of whether a defect exists at the target position of the cable. By measuring the eddy current component in the magnetic field outside the shielding layer, whether a local fault occurs in the cable is detected; the eddy current component is subjected to cluster analysis, and detailed information of the defect can be further obtained. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0043] Figure 1 An application environment diagram of the power distribution cable defect detection method based on current component characteristics in one embodiment;

[0044] Figure 2 A cable current analysis diagram in one embodiment;

[0045] Figure 3 A shielding layer magnetic field distribution diagram generated by a cable defect in one embodiment;

[0046] Figure 4 A flowchart of the power distribution cable defect detection method based on current component characteristics in one embodiment;

[0047] Figure 5 A flowchart of acquiring the current phasor at the target position in one embodiment;

[0048] Figure 6 A flowchart of determining the grounding current component at the target position in one embodiment;

[0049] Figure 7 A flowchart of determining the defect information of the cable according to the analysis result in one embodiment;

[0050] Figure 8 A cluster diagram of a normally operating cable in one embodiment;

[0051] Figure 9 For another embodiment, the defect cable clustering chart;

[0052] Figure 10 For an embodiment, the structure block diagram of the power distribution cable defect detection device based on the current component feature;

[0053] Figure 11 For an embodiment, the schematic diagram of the eddy current acquisition device and the cable position when collecting data;

[0054] Figure 12 For an embodiment, the framework diagram of the eddy current acquisition device;

[0055] Figure 13 For another embodiment, the framework diagram of the ground current acquisition device;

[0056] Figure 14 For an embodiment, the internal structure diagram of the computer device. DETAILED DESCRIPTION

[0057] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0058] The embodiments of the present application relate to a power distribution cable defect detection method based on current component features, such as Figure 1In the application environment shown, the current component feature-based power distribution cable defect detection device 106 can be a terminal device, a server or other device. The current component feature-based power distribution cable defect detection device 106 communicates with the eddy current acquisition device 102 and the grounding current acquisition device 104. The communication can be wireless or wired. The wireless communication can include, but is not limited to, antenna communication and WiFi communication. At the same time, the eddy current acquisition device 102 acquires initial data at the target position of the shielding layer of the cable 108, and the grounding current acquisition device 104 acquires the grounding current at the detection position of the shielding layer. The current component feature-based power distribution cable defect detection device 106 acquires the current phasor at the target position of the shielding layer and the grounding current at the detection position of the shielding layer. The grounding current at the detection position is acquired based on the position of the grounding current acquisition device. The current phasor is determined based on the initial data acquired by the eddy current acquisition device. The current phasor and the grounding current are acquired at the same time. The detection position and the target position are different positions. The grounding current component at the target position is obtained by phase compensation of the grounding current at the detection position of the shielding layer. The eddy current component is obtained by eliminating the grounding current component at the target position from the current phasor at the target position of the shielding layer. The eddy current component is subjected to cluster analysis, and the defect information of the cable is determined based on the analysis result.

[0059] As shown in Figure 2 , the cable includes a core, an insulation layer and a metal shielding layer, wherein the insulation layer wraps the core and the metal shielding layer wraps the insulation layer. Due to the influence of the cable metal shielding layer (referred to as shielding layer), some phenomena caused by insulation defects are shielded or blocked, making it difficult to perform local detection. However, the metal shielding layer is usually made of copper or aluminum, which has a certain attenuation to the magnetic field, but does not shield the magnetic field. Instead, due to the presence of leakage current components in the shielding layer, a corresponding magnetic field is generated on the outside. Figure 2 As shown in , the current components in the cable shielding layer mainly include leakage current components , induced current components and eddy current components . Under normal conditions, the eddy current components cancel each other out and do not propagate along the shielding layer, so the existing technology mainly uses leakage current and induced current. When a local defect occurs in the insulation, the magnetic flux in the local area will change, affecting the eddy current generated at that location, causing the eddy current to be unbalanced, and the eddy current component will appear in the external magnetic field. Based on this principle, the present technology measures the eddy current component in the magnetic field outside the metal shielding layer to detect whether a local fault has occurred in the cable.

[0060] When the medium of the cable is completely uniform, the distribution of eddy current is also uniform, and because of their symmetry and opposition, these currents cancel each other out on a macroscopic level. When the cable has an aging fault, the magnetic flux changes, and the eddy current in the local area changes and no longer cancels each other out, and a vortex component appears in the magnetic field. Figure 3 For a typical defect, the magnetic field distribution at the shielding layer, the insulation defect will cause a significant change in the magnetic field, thereby triggering the imbalance of the eddy current.

[0061] In an exemplary embodiment, as shown in Figure 4 , a power distribution cable defect detection method based on current component characteristics is provided. The method is applied to a server as an example and includes the following steps S402 to S408. Among them:

[0062] Step S402, obtaining the current phasor at the target position of the shielding layer of the cable and the grounding current at the detection position of the shielding layer.

[0063] Among them, the grounding current at the detection position is collected based on the position of the grounding current collection device; the target position is the position of the eddy current collection device; the current phasor is determined based on the initial data collected by the eddy current collection device; the initial data can include the magnetic field strength at the target position; the current phasor and the grounding current are collected at the same time; the detection position and the target position are different positions.

[0064] In actual application, the eddy current collection device and the grounding current collection device are arranged according to the requirements of the cable arrangement; the eddy current collection device is used to measure the magnetic field outside the shielding layer of the cable at time T1, and the data is sent back to the server; the grounding current collection device is used to test the leakage current and the induced current flowing through the shielding layer of the cable at the same time T2, and the data is sent back to the server. Among them, the grounding current collection device uses a core type current sensor; the eddy current collection device uses a patch type sensor.

[0065] Optionally, the server obtains the current phasor at the target position of the shielding layer of the cable , and the current phasor mainly includes a leakage current component , an induced current component and an eddy current component ; the server obtains the grounding current at the detection position of the shielding layer , and the grounding current mainly includes a leakage current component and an induced current component .

[0066] Step S404, phase compensation is performed on the grounding current at the detection position of the shielding layer to obtain the grounding current component at the target position.

[0067] Optionally, since the server acquires data simultaneously from both the grounding current acquisition device and the eddy current acquisition device, and there is a certain electrical distance between the target location and the detection location, there is a phase shift in the grounding current components between the two locations or points. Therefore, the server needs to perform phase compensation on the grounding current at the detection location of the shielding layer to obtain the grounding current component at the target location. .

[0068] Step S406: Eliminate the ground current component at the target location in the current phasor at the target location of the shielding layer to obtain the eddy current component.

[0069] Due to current phasor Mainly includes leakage current component induced current component and eddy current components Grounding current The grounding current mainly includes the leakage current component. induced current component That is, current phasor There is a grounding current component. To obtain the eddy current components at the target location of the shielding layer, the server needs to eliminate the current phasor at that location. Ground current component at the target location eddy current components are obtained. The server calculates the current phasor at the target location of the shielding layer using formula (1). Subtract the grounding current component at the target location Thus, the eddy current component at the target location is obtained. This is so that the eddy current component at the target location can be used to detect whether there are defects in the cable at that location.

[0070] Formula (1)

[0071] In the formula, Eddy current component at the target location , Let be the current phasor at the target location. This represents the grounding current component at the target location.

[0072] Step S408: Perform cluster analysis on the eddy current components and determine the cable defect information based on the analysis results.

[0073] Optionally, the server extracts the amplitude and phase of the eddy current components to obtain eddy current characteristic quantities; and performs cluster analysis on the eddy current characteristic quantities.

[0074] Optionally, after obtaining the eddy current feature quantity, the server performs formula (2) mean value normalization processing on the eddy current feature quantity, and uses a K-means clustering model to perform clustering analysis on the processed eddy current feature quantity.

[0075] Formula (2)

[0076] In the formula, X' is the normalized eddy current feature quantity; X is the eddy current feature quantity to be normalized; μ is the mean value of all eddy current feature quantities to be normalized; X max is the maximum eddy current feature quantity to be normalized; and X min is the minimum eddy current feature quantity to be normalized.

[0077] In actual applications, since the eddy currents are approximately balanced under normal conditions, the differences between them are small, and after clustering, they are generally single-centered or have unclear centers. When a local defect occurs in the cable, the eddy current in the defect area changes sharply, while the eddy current in the non-defect area remains balanced, so that after clustering, double centers or multiple centers appear.

[0078] In the above power distribution cable defect detection method based on current component features, first, the current phasor at the target position of the shielding layer and the ground current at the detection position of the shielding layer are obtained; the ground current at the detection position of the shielding layer is compensated to obtain the ground current component at the target position; second, the ground current component at the target position in the current phasor at the target position of the shielding layer is eliminated to obtain the eddy current component; when a local defect occurs in the insulation layer of the cable, the magnetic flux in the local area changes, affecting the eddy current generated at that position, causing the eddy current to be unbalanced, and the eddy current component appears in the external magnetic field; finally, the eddy current component is subjected to clustering analysis to determine whether there is a defect information at the target position of the cable. By measuring the eddy current component in the magnetic field outside the shielding layer, it is determined whether a local fault occurs in the cable; clustering analysis of the eddy current component can further obtain detailed information of the defect.

[0079] In one exemplary embodiment, as shown in Figure 5 , the current phasor at the target position of the shielding layer of the cable is obtained, including steps S502 to S506. Among them:

[0080] Step S502, a proportionality coefficient is obtained, which is determined according to the current of the cable shielding layer and the magnetic field strength corresponding to the current.

[0081] Wherein, the proportional coefficient is denoted as k, in the laboratory environment, the sample of the same model as the cable to be detected is selected, different currents 0.1A, 0.3A, 0.5A, 0.7A and 0.9A are respectively passed in the cable shielding layer, the eddy current collection device is arranged according to the test method, the output magnetic field intensity under different currents is obtained, and the average proportional coefficient between the current and the magnetic field intensity is established and denoted as k.

[0082] Optionally, the server acquires the pre-computed proportional coefficient k.

[0083] Step S504: acquiring the target magnetic field intensity of the eddy current collection device at the target position of the shielding layer.

[0084] In actual detection, the eddy current collection device is placed at the target position of the cable, and the eddy current collection device collects initial data such as a group of magnetic field intensities , ,……, ].

[0085] Step S506: determining the current phasor at the target position of the shielding layer based on the proportional coefficient and the target magnetic field intensity.

[0086] Since the eddy current collection device adopts a patch type sensor, the output characteristic is by default close to the surface of the conductor (i.e., the cable), but the eddy current collection device may not be able to completely adhere to the surface of the cable. Therefore, the measured current size at this position needs to be corrected.

[0087] Optionally, the server converts the collected magnetic field intensities , ,……, ] into current phasors , ,……, ] through the above proportional coefficient.

[0088] The eddy current collection device can also convert the initial data such as the magnetic field intensity into the current phasor by combining the proportional coefficient, and the eddy current collection device transmits the current phasor to the server for subsequent analysis.

[0089] In the embodiment, the magnetic field intensity collected by the eddy current collection device is converted into the current phasor through the proportional coefficient, which can improve the accuracy of the current phasor at the target position.

[0090] According to any one of the preceding embodiments, as shown in Figure 6 , the ground current at the shielding layer detection position is phase compensated to obtain the ground current component at the target position, including steps S602 to S604. Wherein:

[0091] Step S602, obtaining the phase shift constant, the electrical distance between the detection position and the target position.

[0092] Optionally, the server obtains the phase shift constant ; and the electrical distance l between the detection position and the target position.

[0093] Step S604, determining the ground current component at the target position based on the ground current at the detection position of the shielding layer, the phase shift constant, and the electrical distance between the detection position and the target position.

[0094] Optionally, the server determines the ground current component at the target position based on the ground current at the detection position of the shielding layer, the phase shift constant, and the electrical distance between the detection position and the target position by formula (3).

[0095] Formula (3)

[0096] In the formula, is the ground current component at the target position; is the ground current at the detection position; is the phase shift constant, which is obtained by consulting the actual cable parameters, l is the electrical distance between the detection point and the grounding point, which is obtained by measuring the drawing, and j is the imaginary unit.

[0097] In the embodiment, the ground current at the detection position is compensated by the phase shift constant and the electrical distance between the detection position and the target position to obtain the ground current component at the target position. The accuracy of the ground current component at the target position can be improved.

[0098] In one exemplary embodiment, as Figure 7 shown, the analysis result includes abnormal data; and the defect information of the cable is determined according to the analysis result, including steps S702 to S706. Wherein:

[0099] Step S702, when the number of abnormal data exceeds the defect number threshold, it is determined that the cable has defects.

[0100] Optionally, in order to determine the defects of the cable, the clustering is set to determine the occurrence of cable defects and record the data when the abnormal data exceeds one fourth, and the data is stored in the database.

[0101] The server can obtain the analysis result by principal component analysis. Dark points represent normal data, marked as 1; light points represent abnormal data, marked as 2; and × represents the data center. The cable normal operation clustering diagram is as Figure 8 shown. The defect cable clustering diagram is as Figure 9 shown.

[0102] Step S704, obtaining the reference defect information and the eddy current characteristic database.

[0103] The reference defect information and the eddy current characteristic database are obtained through experiments in advance.

[0104] In a laboratory environment, artificial simulation defect tests are performed on the cable. When the riser is used to apply different currents to the cable, the ground current signal and the eddy current signal are collected, and a typical defect and eddy current characteristic database is established for subsequent field comparison and identification.

[0105] Optionally, the server obtains the reference defect information and the eddy current characteristic database.

[0106] Step S706, determining the defect information of the cable according to the eddy current characteristic and the reference defect and eddy current characteristic database.

[0107] The defect information includes the defect type and the degradation degree.

[0108] Optionally, the server performs one-by-one matching according to the eddy current characteristic and the reference defect and eddy current characteristic database. If the matching is successful, the defect type and the degradation degree of the target position of the cable are determined.

[0109] Optionally, if the matching fails, it indicates that the reference defect and eddy current characteristic database does not exist for this type of defect. Therefore, this type of defect and the corresponding eddy current characteristic are added to the reference defect and eddy current characteristic database, so as to facilitate the server to determine the type and degradation degree of the defect of the local cable in the future.

[0110] In this embodiment, whether the local cable has a defect is determined through analysis results, and then the defect information of the cable is further determined according to the reference defect and eddy current characteristic database, which can improve the accuracy of the cable defect and also determine the type of the defect.

[0111] In an exemplary embodiment, the server obtains a proportionality coefficient k, the proportionality coefficient is determined according to the current of the cable shielding layer and the magnetic field strength corresponding to the current; obtains target magnetic field strengths [ , ,……, ] of the eddy current acquisition device at the target position of the shielding layer; determines the current phasor of the target position of the shielding layer based on the proportionality coefficient k and the target magnetic field strengths [ , ,……, ]; and obtains the ground current at the detection position of the shielding layer. The ground current The ground current is collected based on the position of the ground current collection device; the current phasor and the ground current are collected at the same time; the detection position and the target position are different positions;

[0112] The server obtains the phase shift constant , the electrical distance l between the detection position and the target position, and the ground current at the detection position based on the shielding layer , the phase shift constant , the electrical distance l between the detection position and the target position, and the ground current component at the target position are determined through formula (3) .

[0113] The server eliminates the current phasor at the target position of the shielding layer through formula (1) The ground current component at the target position , to obtain the eddy current component .

[0114] The server performs clustering analysis on the eddy current component, and the analysis result includes abnormal data; when the number of abnormal data exceeds a defect number threshold, it is determined that the cable has defects; reference defect information and an eddy current characteristic quantity database are obtained; and the defect information of the cable is determined according to the eddy current characteristic quantity and the reference defect and the eddy current characteristic quantity database, wherein the defect information includes a defect type and a degradation degree.

[0115] It should be understood that, although each step in the flowchart involved in each embodiment as described above is displayed in sequence according to the arrow, these steps are not necessarily executed in sequence according to the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other sequences. Moreover, at least part of the steps in the flowchart involved in each embodiment as described above can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or steps or stages in other steps.

[0116] Based on the same inventive concept, the embodiments of the present application also provide a current component feature-based power distribution cable defect detection device for implementing the current component feature-based power distribution cable defect detection method described above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more current component feature-based power distribution cable defect detection device embodiments provided below can refer to the limitations of the current component feature-based power distribution cable defect detection method described above, and will not be repeated here.

[0117] In one example embodiment, as shown in Figure 10 A power distribution cable defect detection device based on current component characteristics is provided, comprising: an acquisition module 1001, a compensation module 1002, a cancellation module 1003, and a determination module 1004, wherein:

[0118] The acquisition module 1001 is configured to acquire a current phasor at a target position of a shielding layer of a cable and a grounding current at a detection position of the shielding layer; wherein the grounding current at the detection position is acquired based on a position of a grounding current acquisition device; the current phasor is determined based on initial data acquired by an eddy current acquisition device; the current phasor and the grounding current are acquired at the same time; the detection position and the target position are different positions;

[0119] The compensation module 1002 is configured to perform phase compensation on the grounding current at the detection position of the shielding layer to obtain a grounding current component at the target position;

[0120] The cancellation module 1003 is configured to cancel the grounding current component at the target position from the current phasor at the target position of the shielding layer to obtain an eddy current component;

[0121] The determination module 1004 is configured to perform clustering analysis on the eddy current component and determine defect information of the cable according to an analysis result.

[0122] In one example embodiment, the acquisition module 1001 comprises:

[0123] A first acquisition unit is configured to acquire a proportional coefficient, which is determined according to a current of the shielding layer of the cable and a magnetic field strength corresponding to the current.

[0124] A second acquisition unit is configured to acquire a target magnetic field strength at the target position of the shielding layer by the eddy current acquisition device.

[0125] A current phasor determination unit is configured to determine the current phasor at the target position of the shielding layer based on the proportional coefficient and the target magnetic field strength.

[0126] In one example embodiment, the compensation module 1002 comprises:

[0127] A third acquisition unit is configured to acquire a phase shift constant and an electrical distance between the detection position and the target position.

[0128] A target position current determination unit is configured to determine the grounding current component at the target position based on the grounding current at the detection position of the shielding layer, the phase shift constant, and the electrical distance between the detection position and the target position.

[0129] In one example embodiment, the analysis result includes abnormal data; and the determination module 1004 comprises:

[0130] The judging unit is configured to determine that the cable has a defect when the number of abnormal data exceeds the defect number threshold.

[0131] The fourth obtaining unit is configured to obtain reference defect information and the eddy current characteristic quantity database.

[0132] The defect information determining unit is configured to determine defect information of the cable according to the eddy current characteristic quantity and the reference defect and eddy current characteristic quantity database, wherein the defect information includes a defect type and a degradation degree.

[0133] The above-mentioned various modules in the power distribution cable defect detection device based on current component characteristics can be realized by software, hardware and combinations thereof in whole or in part. The above-mentioned various modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned various modules.

[0134] Based on the same inventive concept, the embodiment of the present application also provides a power distribution cable defect detection system based on current component characteristics for implementing the above-mentioned power distribution cable defect detection method based on current component characteristics, as shown in Figure 1 The power distribution cable defect detection device based on current component characteristics, the eddy current acquisition device and the grounding current acquisition device are in communication connection.

[0135] Taking the power distribution cable defect detection device based on current component characteristics, the eddy current acquisition device and the grounding current acquisition device as an example, the communication mode is an antenna, in addition to the antenna communication, Bluetooth communication or WiFi communication can also be included.

[0136] The eddy current acquisition device is configured to acquire initial data at a target position of the shielding layer, wherein the initial data includes a magnetic field strength.

[0137] The grounding current acquisition device is configured to acquire a grounding current at a detection position of the shielding layer, the detection position being a position of the grounding current acquisition device; the eddy current acquisition device and the grounding current acquisition device acquire at the same time; and the detection position and the target position are different positions.

[0138] The device for detecting defects of power distribution cable based on current component characteristics is used for acquiring a current phasor at a target position of a shielding layer of a cable and a grounding current at a detection position of the shielding layer. The current phasor at the target position of the shielding layer is determined based on initial data. The current phasor and the grounding current are collected at the same time. The grounding current component at the target position is obtained by performing phase compensation on the grounding current at the detection position of the shielding layer. The eddy current component is obtained by eliminating the grounding current component at the target position from the current phasor at the target position of the shielding layer. The eddy current component is subjected to cluster analysis, and the defect information of the cable is determined according to an analysis result.

[0139] In an exemplary embodiment, the eddy current acquisition device comprises: a circular arc shell; a magnetic sensor arranged inside the circular arc shell and used for acquiring initial data at a target position of a shielding layer of a cable, the initial data comprising a magnetic field intensity; a pulley connected to a side of the sensor away from the inside of the circular arc shell and used for moving along an outer circumference of the cable or moving along an axial direction of the cable; a first communication module in communication with the magnetic sensor and used for transmitting a current phasor to the device for detecting defects of power distribution cable based on current component characteristics and receiving a collection time and defect information; and a first processor connected to the first communication module and used for determining the current phasor according to the magnetic field intensity. A display module is arranged outside the circular arc shell and connected to the first processor and used for displaying the magnetic field intensity and the defect information.

[0140] Optionally, as shown in Figure 11 the eddy current acquisition device is in contact with the outside of the cable and used for measuring the magnetic field intensity of the shielding layer of the cable.

[0141] Optionally, as shown in Figure 12 the circular arc shell 1 is designed in a quarter of a circle and made of plastic, and the inner diameter of the circular arc shell 1 is greater than the diameter of the cable.

[0142] A plurality of magnetic sensors 2 are arranged inside the circular arc shell 1 and used for acquiring initial data at a target position of a shielding layer of a cable, the initial data comprising a magnetic field intensity. The magnetic sensor 2 can be a tunnel magnetoresistance (TMR) sensor, which has high measurement accuracy and strong anti-interference capability. For example, 16 TMR sensors can be arranged inside the circular arc shell 1, and the detection direction of the magnetic field is the tangential direction of the circular arc.

[0143] A pulley 3 is connected to a side of the sensor 2 away from the inside of the circular arc shell 1 and used for moving along an outer circumference of the cable or moving along an axial direction of the cable, thereby facilitating determination of the defect position of the cable.

[0144] A first communication module 4 is in communication with the magnetic sensor 2 and used for transmitting a current phasor to the device for detecting defects of power distribution cable based on current component characteristics and receiving a collection time and defect information. The first communication module can be a communication antenna.

[0145] The first processor 5 is connected with the first communication module 4, and is used for determining the current phasor according to the magnetic field intensity.

[0146] The display module 6 is located outside the circular-arc shell 1, and is connected with the first processor 5, and is used for displaying the magnetic field intensity and the defect information.

[0147] In the above embodiment, the thickness of the circular-arc shell is greater than or equal to 20 cm. The metal material in the first processor 5 is away from the magnetic field of the cable to be measured, so as to reduce the interference.

[0148] The grounding current acquisition device, as shown in Figure 13 includes:

[0149] The current transformer 7 is used for measuring the grounding current at the detection position, that is, the leakage current and the induced current combined component.

[0150] The third processor 8 is used for storing and processing the grounding current at the detection position.

[0151] The second communication module 9 is connected with the third processor 8, and is used for sending the grounding current at the detection position measured by the current transformer 7 to the power distribution cable defect detection device based on the current component characteristics, and is also used for receiving the acquisition time.

[0152] The signal cable 10 is connected to the current transformer 7 at one end, and is connected to the third processor 8 at the other end.

[0153] In another embodiment, the grounding current acquisition device includes: a current transformer 7, which is used for measuring the grounding current at the detection position, that is, the leakage current and the induced current combined component; the current transformer 7 is further provided with a third processor 8 and a second communication module 9; the current transformer 7 is connected with the third processor 8; and the third processor 8 and the second communication module 9 are connected.

[0154] In an exemplary embodiment, a computer device is provided, which can be a server, and an internal structure diagram of the computer device can be as shown in Figure 14As shown in the figure. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through the system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capability. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store cable and cable defect data. The input / output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used to communicate with the terminal outside through the network connection. The computer program is executed by the processor to realize a power distribution cable defect detection method based on current component characteristics.

[0155] Those skilled in the art can understand that, Figure 14 The skilled in the art can understand that,

[0156] In one embodiment, a computer device is also provided, including a memory and a processor, the memory stores a computer program, and the processor executes the computer program to realize the steps in each of the above method embodiments.

[0157] In one embodiment, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by the processor to realize the steps in each of the above method embodiments.

[0158] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. The volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0159] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0160] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a specific manner, but should not be construed as limiting the scope of the patent of the present application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for detecting defects in distribution cables based on current component characteristics, characterized in that, The method includes: The method involves acquiring the current phasor at the target location of the cable's shielding layer and the grounding current at the detection location of the shielding layer; wherein the grounding current at the detection location is acquired based on the location of the grounding current acquisition device; the current phasor is determined based on the initial data acquired by the eddy current acquisition device; the current phasor and the grounding current are acquired at the same time; and the detection location and the target location are different locations. Phase compensation is performed on the grounding current at the detection location of the shielding layer to obtain the grounding current component at the target location; Subtract the ground current component at the target location from the current phasor at the target location of the shielding layer to obtain the eddy current component at the target location. The amplitude and phase of the eddy current components are extracted to obtain eddy current characteristic quantities; cluster analysis is performed on the eddy current characteristic quantities, and the defect information of the cable is determined based on the analysis results; the analysis results include abnormal data, including: When the number of abnormal data exceeds the defect number threshold, it is determined that the cable has a defect; Obtain reference defect information and eddy current characteristic quantity database; Based on the eddy current characteristic quantity and the reference defect and eddy current characteristic quantity database, the defect information of the cable is determined, wherein the defect information includes the defect type and the degree of degradation.

2. The method according to claim 1, characterized in that, The acquisition of the current phasor at the target location of the cable's shield layer includes: A proportionality coefficient is obtained, which is determined based on the current in the shielding layer and the magnetic field strength corresponding to the current. The eddy current acquisition device is used to obtain the target magnetic field strength at the target location of the shielding layer. Based on the proportionality coefficient and the target magnetic field strength, the current phasor at the target location of the shielding layer is determined.

3. The method according to claim 1, characterized in that, The step of performing phase compensation on the grounding current at the detection location of the shielding layer to obtain the grounding current component at the target location includes: Obtain the phase shift constant and the electrical distance between the detection position and the target position; Based on the grounding current at the detection location of the shielding layer, the phase shift constant, and the electrical distance between the detection location and the target location, the grounding current component at the target location is determined.

4. A defect detection device for distribution cables based on current component characteristics, characterized in that, The device includes: The acquisition module is used to acquire the current phasor at the target location of the cable's shield layer and the grounding current at the detection location of the shield layer; wherein, the grounding current at the detection location is acquired based on the location of the grounding current acquisition device; the current phasor is determined based on the initial data acquired by the eddy current acquisition device; the current phasor and the grounding current are acquired at the same time; the detection location and the target location are different locations; The compensation module is used to perform phase compensation on the grounding current at the detection location of the shielding layer to obtain the grounding current component at the target location; The elimination module is used to subtract the ground current component at the target location from the current phasor at the target location of the shielding layer to obtain the eddy current component at the target location. The determination module is used to extract the amplitude and phase of the eddy current components to obtain eddy current characteristic quantities; perform cluster analysis on the eddy current characteristic quantities, and determine the defect information of the cable based on the analysis results; the analysis results include abnormal data; The determining module includes: The judgment unit is used to determine that the cable has a defect when the number of abnormal data exceeds the defect number threshold; The fourth acquisition unit is used to acquire reference defect information and eddy current characteristic quantity database; The defect information determination unit is used to determine the defect information of the cable based on the eddy current characteristic quantity and the reference defect and eddy current characteristic quantity database, wherein the defect information includes defect type and degree of degradation.

5. The apparatus according to claim 4, characterized in that, The acquisition module includes: The first acquisition unit is used to acquire the proportional coefficient, which is determined based on the current in the cable shielding layer and the magnetic field strength corresponding to the current. The second acquisition unit is used to acquire the target magnetic field strength of the eddy current acquisition device at the target location of the shielding layer. The current phasor determination unit is used to determine the current phasor at the target location of the shielding layer based on the scaling factor and the target magnetic field strength.

6. A defect detection system for distribution cables based on current component characteristics, characterized in that, The system includes: a power distribution cable defect detection device based on current component characteristics, an eddy current acquisition device, and a grounding current acquisition device; the eddy current acquisition device and the grounding current acquisition device are communicatively connected to the power distribution cable defect detection device based on current component characteristics. The eddy current acquisition device is used to acquire initial data at the target location of the shielding layer; The grounding current acquisition device is used to acquire the grounding current at the detection location of the shielding layer, and the detection location is the location of the grounding current acquisition device; the eddy current acquisition device and the grounding current acquisition device acquire data at the same time; the detection location and the target location are different locations; The power distribution cable defect detection device based on current component characteristics is used to acquire the current phasor at the target location of the cable's shield layer and the grounding current at the detection location of the shield layer; wherein, the grounding current at the detection location is acquired based on the location of the grounding current acquisition device; the current phasor is determined based on the initial data acquired by the eddy current acquisition device; the current phasor and the grounding current are acquired at the same time; the detection location and the target location are different locations; phase compensation is performed on the grounding current at the detection location of the shield layer to obtain the grounding current component at the target location; the current phasor at the target location of the shield layer is... Subtracting the grounding current component at the target location from the measured value yields the eddy current component at the target location; the amplitude and phase of the eddy current component are extracted to obtain eddy current characteristic quantities; cluster analysis is performed on the eddy current characteristic quantities, and the defect information of the cable is determined based on the analysis results; the analysis results include abnormal data, including: when the number of abnormal data exceeds the defect number threshold, it is determined that the cable has a defect; a reference defect information and eddy current characteristic quantity database are obtained; based on the eddy current characteristic quantities and the reference defect and eddy current characteristic quantity database, the defect information of the cable is determined, wherein the defect information includes defect type and degree of degradation.

7. The system according to claim 6, characterized in that, The eddy current acquisition device includes: Arc-shaped shell; A magnetic sensor is disposed inside the arc-shaped housing to collect initial data at the target location of the shielding layer, the initial data including the magnetic field strength. A pulley, connected to the side of the sensor away from the inner side of the arc-shaped housing, is used to move along the outer circumference of the cable or along the axial direction of the cable; The first communication module communicates with the magnetic sensor to transmit the current phasor to the power distribution cable defect detection device based on current component characteristics, and to receive the acquisition time and defect information. A first processor, connected to the first communication module, is used to determine the current phasor based on the magnetic field strength; The display module, located on the outside of the arc-shaped housing and connected to the first processor, is used to display magnetic field strength and defect information.

8. The system according to claim 7, characterized in that, The thickness of the arc-shaped shell is greater than or equal to 20 cm.

9. A computer device comprising a memory and a second processor, wherein the memory stores a computer program, characterized in that, When the second processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 3.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

Images