Cable outer sheath damage detection method and system based on material surface electrothermal coupling sensing

Abstract

The invention relates to the technical field of cable outer sheath damage detection, in particular to a cable outer sheath damage detection method and system based on material surface electrothermal coupling sensing. Specifically, straight-through current sensors are arranged on the two sides of a cable to measure currents on the left side and the right side and calculate leakage current distribution; measuring the surface temperature distribution of the cable by arranging a thermocouple sensor, and positioning the damage position based on the difference temperature; based on the leakage current distribution information and the temperature distribution information, a D-S evidence theory information fusion model is established for damage detection, feature vectors are extracted through wavelet packet decomposition, and the recognition rate of each defect mode is obtained in combination with neural network training. Current detection and temperature detection are organically combined, a complete electrothermal coupling sensing system is constructed, accurate detection and positioning of cable outer sheath damage are realized, the detection time is shortened to the minute level from the hour level, the positioning precision is improved to the centimeter level, and a reliable diagnosis basis is provided for cable maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of cable outer sheath damage detection, and in particular to a cable outer sheath damage detection method and system based on material surface electrothermal coupling perception. Background Art

[0002] Traditional cable operation status monitoring technology determines the internal breakdown and aging of the cable by measuring parameters such as partial discharge signals, electric fields, and temperature. However, the multi-physical field coupling mechanism and characteristics when the cable outer sheath is damaged are not yet clear, and it is impossible to improve the accuracy and stability of feature extraction. Therefore, it is difficult for traditional sensors to accurately identify and locate the external damage area. Specifically, there are the following problems:

[0003] First, the existing technology mainly focuses on monitoring the insulation performance of the cable, and evaluates the cable status through single parameters such as partial discharge signal and dielectric loss factor. This method ignores the multi-physical field coupling effect caused by the damage of the outer sheath, resulting in insufficient detection accuracy. For example, when the outer sheath is slightly damaged, it is difficult to detect and accurately locate the fault point in time by relying on a single parameter.

[0004] Secondly, the traditional detection method lacks an effective information fusion mechanism. Although multiple parameters can be measured simultaneously, each parameter is independent of each other, and no correlation analysis between parameters has been established. This fragmented detection method cannot fully reflect the characteristics of outer sheath damage, resulting in misjudgment or missed judgment. For example, temperature anomalies may be caused by a variety of reasons, and it is difficult to determine whether the outer sheath is indeed damaged by relying solely on temperature data.

[0005] Third, the existing technology is insufficient in the positioning accuracy of outer sheath damage detection. Due to the lack of accurate measurement and correlation analysis of leakage current and temperature field distribution, it is difficult to accurately locate the damage position. This leads to low efficiency of maintenance work and increased maintenance costs.

[0006] Fourth, the existing detection methods generally lack theoretical support. There is a lack of in-depth research on the physical processes such as current leakage and temperature field changes caused by damage to the outer sheath, and no complete theoretical model has been established, which makes the detection methods lack scientific basis.

[0007] Therefore, it is urgent to propose a new detection method that can simultaneously obtain leakage current distribution and temperature field distribution information, and establish correlation analysis between multiple parameters through information fusion technology, so as to improve the accuracy and positioning accuracy of outer sheath damage detection. Traditional cable operation status monitoring technology determines the internal breakdown and aging of the cable by measuring parameters such as partial discharge signals, electric fields, and temperature. However, the multi-physical field coupling mechanism and characteristics when the outer sheath of the cable is damaged are not yet clear, and it is impossible to improve the accuracy and stability of the extracted feature quantity. Therefore, it is difficult for traditional sensors to accurately identify and locate the external damage area. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention is proposed.

[0009] The problem to be solved by the present invention is how to solve the problem of insufficient single parameter detection accuracy in traditional cable outer sheath damage detection; the lack of multi-parameter information fusion mechanism of electrothermal coupling in traditional detection methods, resulting in low reliability of detection results; and the problem of insufficient positioning accuracy of the outer sheath damage position in the existing technology.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] In a first aspect, an embodiment of the present invention provides a cable outer sheath damage detection method based on material surface electrothermal coupling perception, which includes obtaining leakage current distribution information of the cable outer sheath;

[0012] Obtain temperature distribution information of cable outer sheath;

[0013] Based on the leakage current distribution information and the temperature distribution information, an information fusion model is established to perform damage detection.

[0014] As a preferred solution of the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to the present invention, the step of obtaining leakage current distribution information of the cable outer sheath comprises:

[0015] Arrange through-type current sensors on both sides of the cable to measure the current on the left and right sides;

[0016] Based on the measured currents on the left and right sides, the leakage current distribution is calculated.

[0017] As a preferred solution of the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to the present invention, the step of obtaining the temperature distribution information of the cable outer sheath comprises:

[0018] Use thermocouple sensors to measure the cable surface temperature distribution;

[0019] The damaged part of the cable sheath can be located based on the temperature difference.

[0020] As a preferred solution of the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to the present invention, the step of establishing an information fusion model for damage detection includes:

[0021] Construct information fusion model based on DS evidence theory;

[0022] Get the identification result and determine the positioning criterion.

[0023] As a preferred solution of the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to the present invention, the information fusion model constructed based on DS evidence theory includes:

[0024] Construct an identification framework including scratch defect mode and breakage defect mode;

[0025] The leakage current characteristics and the differential temperature characteristics are selected as the evidence bodies.

[0026] As a preferred solution of the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to the present invention, the DS evidence theory information fusion model also includes:

[0027] Determine the basic credibility assignment for each body of evidence;

[0028] The characteristic vectors of leakage current and differential temperature are obtained by wavelet packet decomposition;

[0029] Perform weighted fusion of evidence.

[0030] As a preferred solution of the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to the present invention, the step of determining the basic credibility assignment of each evidence body includes:

[0031] Divide into training set and test set;

[0032] The recognition rate of each defect mode is obtained by neural network training.

[0033] In a second aspect, an embodiment of the present invention provides a cable outer sheath damage detection system based on material surface electrothermal coupling perception, which includes a current acquisition module to obtain leakage current distribution information of the cable outer sheath;

[0034] Temperature acquisition module, to obtain the temperature distribution information of the cable outer sheath;

[0035] The detection module establishes an information fusion model for damage detection based on the leakage current distribution information and the temperature distribution information.

[0036] In a third aspect, an embodiment of the present invention provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the cable outer sheath damage detection method based on material surface electrothermal coupling perception as described in the first aspect of the present invention are implemented.

[0037] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the cable sheath damage detection method based on material surface electrothermal coupling perception as described in the first aspect of the present invention are implemented.

[0038] The beneficial effects of the present invention are as follows: the present invention designs a fixed-point area detection sensor for local leakage current and differential temperature; the present invention proposes a fixed-point area sensing detection technology based on local leakage current and differential temperature of cable outer sheath damage, as well as a cable outer sheath damage detection criterion based on multi-sensor information fusion, to achieve accurate detection and identification of cable microscopic damage point defects, effectively improve the cable operation reliability, reduce maintenance workload, and reduce production losses caused by cable failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 It is a flow chart of the cable outer sheath damage detection method based on the electrothermal coupling perception of the material surface;

[0041] Figure 2 A computer device diagram of a cable sheath damage detection method based on material surface electrothermal coupling perception;

[0042] Figure 3 The cable structure diagram of the cable outer sheath damage detection method based on the electrothermal coupling perception of the material surface (taking a single-core cable as an example);

[0043] Figure 4 It is a cable outer sheath damage leakage current trend diagram of the cable outer sheath damage detection method based on the material surface electrothermal coupling perception;

[0044] Figure 5 Schematic diagram of the cable leakage current measured by the sensor of the cable sheath damage detection method based on the electrothermal coupling perception of the material surface;

[0045] Figure 6 This is a schematic diagram of the DS evidence theory multi-information fusion and recognition process of the cable sheath damage detection method based on material surface electrothermal coupling perception. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0047] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0048] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0049] Example 1

[0050] Reference Figure 1 to Figure 6 , which is the first embodiment of the present invention, provides a cable outer sheath damage detection method based on material surface electrothermal coupling perception, including:

[0051] S100: Obtain leakage current distribution information of the cable outer sheath;

[0052] Preferably, a through-type current sensor is used to measure the leakage current distribution when the outer sheath of the cable is damaged;

[0053] S101: The step of obtaining leakage current distribution information of the cable outer sheath comprises:

[0054] Arrange through-type current sensors on both sides of the cable to measure the current on the left and right sides;

[0055] Based on the measured currents on the left and right sides, the leakage current distribution is calculated.

[0056] Preferably, according to Figure 3 The cable structure diagram shown (taking a single-core cable as an example) consists of an inner semi-conductive layer, a main insulating layer and an outer semi-conductive layer. The cable outer sheath is surrounded by the metal sheath. When the cable outer sheath is damaged, the metal sheath will induce voltage to the ground. At this time, the leakage current will flow from the metal sheath at the damaged part through the outer sheath and the left and right brackets of the cable into the ground.

[0057] Taking a single-core cable as an example, the T-type equivalent circuit of its metal sheath and outer sheath is as follows: Figure 4 shown.

[0058] Among them, I leak is the leakage current in the outer sheath, Z L , Z R are the equivalent impedance of the outer sheath between the metal sheath and the cable support, Z1 is the equivalent impedance of the metal sheath, I L,I R They are the insulation current components on the left and right sides respectively, and U1 is the voltage to ground induced by the metal sheath due to the damage of the outer sheath. Figure 4 The T-type equivalent circuit shown in Figure 1 shows that I L ,I R and I leak The relationship is always satisfied:

[0059] I leak =I L +I R

[0060] Therefore, the sum of IL and IR is the leakage current of the outer sheath of the cable segment. Two through-hole Hall current sensors are clamped on both sides of the cable segment for measurement. The measurement diagram is shown in the figure. Figure 5 As shown. The current measurement values ​​I of the two through-type current sensors on the left and right LCT , I RCT They are

[0061] I LCT =I leak +I S -I L

[0062] I RCT =I leak +I S +I R

[0063] Therefore, the leakage current is

[0064] I leak =I LCT -I RCT

[0065] When the cable outer sheath is damaged, the detected I leak >0, otherwise the induced voltage U1=0, I leak = 0. Therefore, by judging whether the leakage current is zero, it can be judged whether the outer sheath of the cable is damaged.

[0066] S200: Acquire temperature distribution information of the outer sheath of the cable;

[0067] Preferably, a thermocouple sensor is used to measure the temperature distribution of the cable, and the damaged position of the cable outer sheath is located based on the differential temperature;

[0068] S201: The step of obtaining the temperature distribution information of the cable outer sheath comprises:

[0069] Use thermocouple sensors to measure the cable surface temperature distribution;

[0070] The damaged part of the cable sheath can be located based on the temperature difference.

[0071] Preferably, according to Figure 3 The structure diagram of a single-core cable, the equivalent capacitance C0 and conductance G0 per unit length of the outer sheath are

[0072]

[0073] Where ε and γ are the dielectric constant and conductivity of the outer sheath, respectively, and d1 and c1 are the outer diameter and inner diameter of the outer sheath, respectively. For a cable of length l, the heating power of the leakage current is

[0074]

[0075] For the heat conduction problem of solid medium (cable body), the heat conduction differential equation is as follows:

[0076]

[0077] in, Indicates solid density; C p represents the specific heat capacity at normal pressure; Q represents the heat source; k represents the thermal conductivity; and T represents the temperature.

[0078] The energy calculation formula for thermal radiation in air is:

[0079] Q=σδA1T 4

[0080] Among them, σ represents the emissivity of the object surface; δ represents the Stefan-Boltzmann constant; A1 represents the effective area.

[0081] Due to the leakage current in the outer sheath of the cable, the temperature at the damaged part is abnormally high, so the temperature measurement device can be used to measure the temperature distribution around the cable to locate the damaged part. Figure 5 shown.

[0082] S300: Based on the leakage current distribution information and the temperature distribution information, an information fusion model is established to perform damage detection.

[0083] Preferably, the differential current information and temperature information are integrated, and information fusion is performed based on the DS evidence theory to obtain the identification result, and the positioning criterion is obtained to achieve the purpose of detecting the damage of the cable outer sheath.

[0084] S301: The steps of establishing an information fusion model for damage detection include:

[0085] Construct information fusion model based on DS evidence theory;

[0086] Get the identification result and determine the positioning criterion.

[0087] S302: Constructing an information fusion model based on DS evidence theory includes:

[0088] Construct an identification framework including scratch defect mode and breakage defect mode;

[0089] The leakage current characteristics and the differential temperature characteristics are selected as the evidence bodies.

[0090] S303: The DS evidence theory constructs the information fusion model and also includes:

[0091] Determine the basic credibility assignment for each body of evidence;

[0092] The characteristic vectors of leakage current and differential temperature are obtained by wavelet packet decomposition;

[0093] Perform weighted fusion of evidence.

[0094] S304: The step of determining the basic credibility assignment of each body of evidence includes:

[0095] Divide into training set and test set;

[0096] The recognition rate of each defect mode is obtained by neural network training.

[0097] Preferably, DS evidence theory is one of the multi-sensor data fusion methods, which can reduce the information loss of a single detection method and improve the performance of intelligent detection systems with multiple detection methods. For the cable sheath damage detection scenario based on the electrothermal coupling perception of the material surface, the DS evidence theory method objectively handles fuzzy and uncertain information such as leakage current characteristics and temperature thermal field distribution, and obtains a higher confidence judgment result by fusing the independent judgments of multiple incompatible evidence bodies on the identification framework sub-propositions. Figure 6 As shown in the figure, the specific identification steps based on DS multi-source fusion are as follows:

[0098] (1) Construct the identification framework Θ. If the n typical insulation modes of the cable outer sheath are denoted as A1, A2, …A n , then its identification framework is Θ={A1,A2,…A n The cable outer sheath includes scratches and damages, so the identification framework is Θ = {A1, A2}, where A1 is the scratch defect mode and A2 is the damage defect mode.

[0099] (2) Select evidence. Use leakage current features for identification as evidence 1, and use temperature difference features for identification as evidence 2. Decompose the changes of leakage current and temperature difference over time into wavelet packets, and use the node energy of wavelet packet decomposition as its feature vectors e1 and e2.

[0100] (3) Determine the basic reliability assignment of each evidence body. Use part of the data as the training set and use the leakage current feature vector e1 of the training set to train the neural network of evidence body 1. Use the remaining data as the test set to test the neural network and obtain the recognition rate S1 (A) of each defect mode of evidence body 1. j ); Similarly, the recognition rate S2(A j ).

[0101] (4) The two pieces of evidence are weighted and fused to obtain the weighted confidence assignment m(A) for each typical pattern after the weighted fusion of the two pieces of evidence. j ) and its Bel(A j ) and Pl(A j ), thereby obtaining the positioning criteria and achieving the purpose of detecting cable outer sheath damage.

[0102] Furthermore, this embodiment also provides a cable outer sheath damage detection system based on material surface electrothermal coupling perception, including:

[0103] A current acquisition module is used to obtain the leakage current distribution information of the cable outer sheath;

[0104] Temperature acquisition module, to obtain the temperature distribution information of the cable outer sheath;

[0105] The detection module establishes an information fusion model for damage detection based on leakage current distribution information and temperature distribution information.

[0106] In summary, by arranging through-type current sensors on both sides of the cable to measure the leakage current distribution on the left and right sides, and combining the T-type equivalent circuit model to analyze the leakage current characteristics, the preliminary positioning of the damaged point of the cable outer sheath is achieved, overcoming the technical problem that traditional single-point measurement cannot determine the damaged position, and achieving the effect of quickly judging whether there is outer sheath damage.

[0107] By deploying a thermocouple sensor array to measure the surface temperature distribution of the cable, a corresponding relationship between temperature anomalies and damage locations was established based on the relationship between the Joule heat generated by the leakage current and the surrounding temperature difference. This solves the problem in the existing technology that it is difficult to determine the cause of the anomaly by relying solely on a single temperature parameter, and achieves accurate positioning of the damage location.

[0108] By establishing an information fusion model based on DS evidence theory, the leakage current characteristics and temperature distribution characteristics are taken as two independent evidence bodies for fusion analysis, and wavelet packet decomposition is introduced to extract feature vectors, thus realizing the complementary advantages of multi-source information and significantly improving the reliability of detection results. The detection accuracy rate reaches more than 95%.

[0109] By using neural network training to determine the basic reliability assignment of each body of evidence, the self-learning optimization of the detection system is achieved, the problem of poor adaptability of the traditional empirical threshold judgment method is solved, and the system has good generalization ability.

[0110] The present invention organically combines current detection and temperature detection to construct a complete electrothermal coupling sensing system, which can not only detect damage to the cable outer sheath in a timely manner, but also accurately identify the type of damage (scratches or damage), providing a comprehensive diagnostic basis for cable maintenance and achieving unexpected technical effects: the detection time is shortened from several hours of traditional manual inspection to minutes; the positioning accuracy is improved from meters to centimeters; and the damage type can be distinguished to avoid misjudgment and excessive repairs.

[0111] The implementation of the method of the present invention does not require changing the existing cable structure, and only requires adding a detection device externally. It has good engineering practicality and promotion value, can effectively reduce the power grid operation and maintenance costs, and improve power supply reliability.

[0112] Example 2

[0113] Reference Figure 2 - Figure 6 , which is the second embodiment of the present invention, provides a cable outer sheath damage detection method based on material surface electrothermal coupling perception. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0114] In order to verify the feasibility and advancement of the method of the present invention, a field test was carried out in a 220kV substation of a certain power grid company. The test site was selected in the incoming cable area of ​​the substation. The test object was a single-core high-voltage cable in operation, with an outer diameter of 180mm and an outer sheath thickness of 3mm. Three defects of different degrees were artificially created on the outer sheath of the cable: A was a slight scratch (depth 0.5mm, length 10mm), B was a moderate scratch (depth 1.5mm, length 20mm), and C was severely damaged (depth 2.5mm, area about 100mm 2 ).

[0115] In terms of experimental arrangement, a group of thermocouple sensors are arranged every 50cm along the length of the cable, with a total of 20 groups of temperature measurement points. T-type thermocouples are used, and the temperature measurement accuracy is ±0.1℃. Four sensors are evenly arranged along the circumference of the cable for each group of temperature measurement points to eliminate the uneven influence of ambient temperature. A through-hole Hall current sensor (model HST-200, range 0-200mA, accuracy 0.1mA) is installed 1m on both sides of the defect to measure the leakage current. All sensors are connected to the industrial computer through a data acquisition device (sampling frequency 1kHz) to collect data in real time.

[0116] The test process is divided into three stages: the first stage (0-2h) collects benchmark data under normal operating conditions; the second stage (2-4h) applies 1.2 times the rated voltage to the cable to accelerate the development of defects; the third stage (4-8h) restores normal voltage and continues monitoring. The collected raw data is decomposed and denoised by wavelet packets, and the feature vector is extracted and input into the pre-trained DS evidence theory fusion model for analysis.

[0117] A total of 50 groups of comparative experiments were conducted in the field test, each group of experiments lasted for 8 hours. The following table lists the performance comparison data of the method of the present invention and the traditional single parameter detection method:

[0118]

[0119] The following conclusions can be drawn from the analysis of experimental data:

[0120] In terms of detection time, the method of the present invention is significantly better than traditional single parameter detection. With the rapid positioning of the dual current sensors and the real-time monitoring of the temperature array, the average detection time is only 15 minutes, which is 66.7% shorter than the current method alone and 87.5% shorter than the temperature method. This efficiency improvement is due to the parallel monitoring strategy and intelligent data processing algorithm adopted by the present invention.

[0121] In terms of positioning accuracy, the method of the present invention achieves centimeter-level accuracy (3±1cm), which is far superior to traditional methods. This is due to the multi-dimensional positioning principle of electrothermal coupling: current measurement provides preliminary positioning, and temperature distribution provides precise positioning, and the two complement each other. Especially in the detection of moderate scratches at B, the spatial correlation between the temperature anomaly point and the leakage current keeps the positioning error within 2cm.

[0122] In terms of reliability indicators, the missed detection rate and false detection rate of the present invention are both less than 2%, and the comprehensive recognition accuracy rate reaches 97.3%. In contrast, the accuracy rate of single parameter detection methods is generally less than 85%. This significant improvement is attributed to the information fusion mechanism of DS evidence theory: when a temperature anomaly occurs at a certain place, the system will automatically analyze the leakage current characteristics of the place, and effectively reduce the probability of misjudgment through cross-validation.

[0123] In terms of fault type identification, the present invention can not only detect the location of damage, but also accurately distinguish damage of different degrees. For example, for a slight scratch at point A, the temperature rise is not obvious but there is a weak leakage current; severe damage at point C is manifested as obvious temperature abnormality and large leakage current. This hierarchical diagnosis capability provides an important basis for maintenance decisions.

[0124] In summary, a large amount of comparative test data proves that the method of the present invention has achieved significant breakthroughs in detection efficiency, accuracy and reliability, and has achieved unexpected technical effects. These improvements are not simply performance superposition, but produce beneficial effects through electrothermal coupling perception and information fusion, providing a new solution for power cable condition monitoring.

[0125] Example 3

[0126] This embodiment also provides a computer device, which is applicable to a cable outer sheath damage detection method based on material surface electrothermal coupling perception, and includes a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement a forced oscillation detection and positioning method for a distribution network as proposed in the above embodiment.

[0127] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, a method for detecting damage of a cable outer sheath based on electrothermal coupling perception of the material surface as proposed in the above embodiment is implemented.

[0128] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. 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 and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0129] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0130] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0131] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0132] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0133] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A cable outer sheath damage detection method based on material surface electrothermal coupling perception, characterized in that: include, Obtain leakage current distribution information of cable outer sheath; Obtain temperature distribution information of cable outer sheath; Based on the leakage current distribution information and the temperature distribution information, an information fusion model is established to perform damage detection.

2. The cable outer sheath damage detection method based on material surface electrothermal coupling perception as claimed in claim 1 is characterized by: The step of obtaining the leakage current distribution information of the cable outer sheath comprises: Arrange through-type current sensors on both sides of the cable to measure the current on the left and right sides; Based on the measured currents on the left and right sides, the leakage current distribution is calculated.

3. The cable outer sheath damage detection method based on material surface electrothermal coupling perception as claimed in claim 2 is characterized by: The step of obtaining the temperature distribution information of the cable outer sheath comprises: Use thermocouple sensors to measure the cable surface temperature distribution; The damaged part of the cable sheath can be located based on the temperature difference.

4. The cable outer sheath damage detection method based on material surface electrothermal coupling perception as claimed in claim 3 is characterized by: The step of establishing an information fusion model for damage detection includes: Construct information fusion model based on DS evidence theory; Get the identification result and determine the positioning criterion.

5. The cable outer sheath damage detection method based on material surface electrothermal coupling perception as claimed in claim 4 is characterized by: The information fusion model constructed based on DS evidence theory includes: Construct an identification framework including scratch defect mode and breakage defect mode; The leakage current characteristics and the differential temperature characteristics are selected as the evidence bodies.

6. The cable outer sheath damage detection method based on material surface electrothermal coupling perception as claimed in claim 5 is characterized by: The DS evidence theory constructs the information fusion model and further includes: Determine the basic credibility assignment for each body of evidence; The characteristic vectors of leakage current and differential temperature are obtained by wavelet packet decomposition; Perform weighted fusion of evidence.

7. The cable outer sheath damage detection method based on material surface electrothermal coupling perception as claimed in claim 6 is characterized by: The step of determining the basic credibility assignment of each body of evidence comprises: Divide into training set and test set; The recognition rate of each defect mode is obtained by neural network training.

8. A cable outer sheath damage detection system based on material surface electrothermal coupling perception, based on the cable outer sheath damage detection method based on material surface electrothermal coupling perception according to any one of claims 1 to 7, characterized in that: Also includes, A current acquisition module is used to obtain the leakage current distribution information of the cable outer sheath; Temperature acquisition module, to obtain the temperature distribution information of the cable outer sheath; The detection module establishes an information fusion model for damage detection based on the leakage current distribution information and the temperature distribution information.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the cable outer sheath damage detection method based on material surface electrothermal coupling perception as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the cable outer sheath damage detection method based on material surface electrothermal coupling perception as described in any one of claims 1 to 7 are implemented.

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