Cable buffer layer ablation defect positioning method and system and storage medium

Abstract

The invention relates to a cable buffer layer ablation defect positioning method and system and a storage medium, and the method comprises the steps: obtaining a real broadband impedance spectrum of a cable to be subjected to defect positioning through a broadband impedance method, and building N simulation cables with the same length as the cable to be subjected to defect positioning, fitting the N simulation cables and the cable to be subjected to defect positioning through a genetic algorithm to obtain a defect positioning simulation cable; and processing the defect positioning simulation cable through a broadband impedance spectroscopy method to obtain an ablation degree positioning curve of the cable to be subjected to defect positioning. According to the invention, fitting can be carried out on the cable with multiple buffer layer defects, identification of multiple defect points can be realized, and nondestructive testing and positioning can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of analyzing materials by testing impedance, and in particular to a method, system and storage medium for locating ablation defects in a cable buffer layer. Background Art

[0002] Cross-linked polyethylene (XLPE) cables, an indispensable component of modern power transmission systems, are widely used in power transmission and distribution projects due to their excellent electrical, mechanical, and thermal properties. These cables, insulated with XLPE, not only possess a high thermal resistance rating but also exhibit excellent dielectric properties and mechanical strength, making them adaptable to complex and changing operating environments. However, over the long term, the insulation performance of these cables is significantly affected by various environmental factors, including humidity fluctuations, chemical corrosion, and mechanical stress. These factors can lead to defects in the cable insulation, particularly erosion of the buffer layer. These defects manifest as decreased insulation resistance, increased dielectric loss, and intensified partial discharge, significantly increasing the likelihood of cable failure. To ensure the safe and reliable operation of power systems, extend cable service life, improve power transmission efficiency, and reduce power outages and economic losses caused by failures, it is essential to establish a comprehensive cable condition monitoring system that accurately identifies and locates the extent of buffer layer erosion.

[0003] Currently, cable fault detection technology primarily focuses on the precise location of cable defects, primarily employing frequency domain reflectometry (FDR). This method uses broadband impedance spectroscopy (BIS) to convert collected frequency domain data into intuitive location spectra through signal processing methods such as Fourier transform and wavelet transform, thereby accurately identifying and locating cable defects. Chinese invention patent application publication number CN118551345A discloses a method for diagnosing defects in high-voltage cable water-blocking buffer layers based on a U-NET structure. This method uses broadband impedance spectroscopy to simulate the characteristic impedance changes after a defect in the cable water-blocking buffer layer, generating a series of data labeled with cable defect severity. This data is then fed into a defect prediction model for training, and the trained defect prediction model is used to diagnose defects in the cable water-blocking buffer layer. While this method can diagnose defects in the cable water-blocking buffer layer, it relies heavily on data labeled with cable defect severity, requiring a large amount of data for model training, making the process cumbersome. Summary of the Invention

[0004] The present invention provides a method for locating ablation defects of a cable buffer layer, which can quickly and accurately locate the ablation defects of the cable buffer layer.

[0005] According to a first aspect of the present invention, a method for locating ablation defects in a cable buffer layer is provided, comprising the following steps:

[0006] Step 1: Using the broadband impedance spectrum method, the input frequency range of the cable to be located for buffer layer ablation defect location is The broadband signal is obtained to obtain the real broadband impedance spectrum of the cable to be defect-located. ;

[0007] Step 2: Establish N simulated cables of the same length as the cable to be defect located; obtain simulated cable ablation degree sequences of the N simulated cables, and obtain simulated capacitance sequences of the N simulated cables through the N simulated cable ablation degree sequences;

[0008] Step 3: Fitting the simulated cable ablation degree sequence and the simulated capacitance sequence to the cable to be defect located by a genetic algorithm to obtain N simulated cables for defect location;

[0009] Step 4: Simulate N defect location simulation cables using transmission line theory and process the simulation results to obtain a cable ablation degree sequence of the cable to be defect located;

[0010] Step 5: Use cubic spline interpolation method to form transition segments between n cable ablation degree values ​​in the cable ablation degree sequence to obtain the ablation degree location curve of the defect location simulation cable. , as shown in the following formula (1),

[0011] (1)

[0012] In formula (1), are the difference coefficients obtained by cubic spline interpolation method;

[0013] Select the ablation degree positioning curve Greater than the ablation defect judgment threshold The position is the position where the buffer layer ablation defect occurs in the cable to be defect located.

[0014] Furthermore, the specific process of obtaining the simulated cable ablation degree sequence of N simulated cables in step 2 is as follows: n random numbers are taken N times in the interval [0,1] and collected respectively to form the first sequence, the second sequence to the Nth sequence, and the first sequence, the second sequence to the Nth sequence are defined as the first simulated cable ablation defect degree sequence of the first simulated cable, the second simulated cable to the Nth simulated cable in the N simulated cables. , the second simulated cable ablation defect degree sequence To the Nth simulated cable ablation defect degree sequence .

[0015] Furthermore, the specific process of obtaining the simulated capacitance sequence of N simulated cables in step 2 is as follows: the first simulated cable ablation defect degree sequence , the second simulated cable ablation defect degree sequence To the Nth simulated cable ablation defect degree sequence Substitute the following formula (2) in sequence to calculate the first simulated capacitance sequence of the first simulated cable, the second simulated cable to the Nth simulated cable: , the second simulated capacitor sequence To the Nth analog capacitor sequence ,

[0016] (2)

[0017] In formula (2), is the e-th simulated capacitor sequence of the e-th simulated cable; is the capacitance sequence of a cable with the same length as the cable to be located and without defects, It is the defect degree sequence of the e-th simulated cable ablation degree of the e-th simulated cable.

[0018] Furthermore, the specific process of simulating N defect location simulation cables using transmission line theory in step 4 is as follows: N defect location simulation cables are sequentially input into Frequency of range changes , N simulated broadband impedance spectra are obtained by the following formula (3):

[0019] (3)

[0020] In formula (3), is the simulated broadband impedance spectrum of the e-th defect location simulation cable among the N defect location simulation cables; The simulated capacitance sequence of the e-th defect location simulated cable; is the imaginary part in the process of simulating broadband impedance spectroscopy; 、 and The resistance sequence, inductance sequence and conductance sequence of a cable with the same length as the cable to be located and without defects;

[0021] The specific process of processing the simulation results in step 4 to obtain the cable ablation degree sequence of the cable to be defect located is as follows: N simulated broadband impedance spectra obtained by simulating N defect location simulated cables are sequentially subtracted from the real broadband impedance spectrum, and the simulated cable ablation degree sequence of the defect location simulated cable corresponding to the simulated broadband impedance spectrum with the smallest difference is used as the cable ablation degree sequence of the cable to be defect located.

[0022] Furthermore, the specific fitting process in step 3 is as follows:

[0023] Step 3.1: Initialize the fitting number i so that the fitting number i is equal to 1; use the initial population as the first population when the fitting number i is equal to 1;

[0024] Step 3.2: Input the N simulated cables in the first group in turn. Frequency of range changes And the first judgment broadband impedance spectrum from the first simulation cable to the Nth simulation cable in the first population is obtained by the principle of formula (3): To the Nth judgment broadband impedance spectrum ;

[0025] Step 3.3: The first judgment broadband impedance spectrum of the first population To the Nth judgment broadband impedance spectrum and the real broadband impedance spectrum Substitute into the following formula (4) in turn to calculate the N residual values ​​between the first population and the cable to be located ,

[0026] (4)

[0027] In formula (4), is the e-th judgment broadband impedance spectrum among the N judgment broadband impedance spectra; is the With the The residual value between

[0028] If the N residual values ​​between the first population and the cable to be located are all less than the residual judgment threshold , then the first population is output as the optimal population, the fitting is stopped, and the following step 3.4 is executed;

[0029] If the N residual values ​​between the first population and the cable to be located are not less than the residual judgment threshold In the case of , the fitting times i is increased by 1, and the simulated cable ablation degree sequences of the N simulated cables in the first population are updated in sequence by the following formula (5), and the simulated cable ablation degree sequences of the N simulated cables when the fitting times i is equal to 2 are obtained.

[0030] (5)

[0031] In formula (5), is the crossover mutation update operator in the genetic algorithm; and are the simulated cable ablation degree sequences of the e-th simulated cable of the N simulated cables before and after the update;

[0032] The simulated cable ablation degree sequence of the N simulated cables when the fitting number i is equal to 2 is calculated using the principle of formula (2) to obtain the simulated capacitance sequence of the N simulated cables when the fitting number i is equal to 2; the simulated cable ablation degree sequence and the simulated capacitance sequence of the N simulated cables when the fitting number i is equal to 2 are used as the second population, and the following step 3.4 is continued;

[0033] Step 3.4: Replace the population obtained in step 3.3 with the population in step 3.2 and repeat steps 3.2 to 3.3 until the optimal population is obtained;

[0034] Step 3.5: The N simulated cables represented by the N simulated cable ablation degree sequences and simulated capacitance sequences in the optimal population obtained in step 3.4 are used as N defect location simulated cables.

[0035] According to a second aspect of the present invention, a cable buffer layer ablation defect positioning system equipped with the above positioning method is provided, comprising:

[0036] A real broadband impedance spectrum acquisition module is used to obtain the real broadband impedance spectrum of the cable to be defect-located;

[0037] A simulated cable generation module is used to generate a simulated cable with the same length as the cable with defect location and obtain physical parameters of the simulated cable;

[0038] A defect location simulation cable generation module is used to fit the simulation cable with the defect location cable to obtain the defect location simulation cable;

[0039] The ablation defect location module locates the degree of ablation defects of the defect location cable through the defect location simulation cable.

[0040] According to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, all steps of the above positioning method are implemented.

[0041] The present invention has the following beneficial effects:

[0042] The present invention creates N simulated cables of the same length as the cable to be defect-located and uses a genetic algorithm to fit these N simulated cables to the cable to be defect-located, thereby generating a simulated cable for defect location. The simulated cables are then processed using a broadband impedance spectroscopy method to generate a curve for the degree of ablation of the cable to be defect-located. This method can fit multiple buffer layer defects in cables, identify multiple defects, and achieve nondestructive testing and location. Furthermore, the present method for locating cable buffer layer ablation defects can be more easily applied to different scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is the overall process structure diagram of the present invention.

[0044] Figure 2 1 is a flow chart of a specific fitting process in an embodiment of the present invention.

[0045] Figure 3 Schematic diagram of the process of determining the broadband impedance spectrum obtained in an embodiment of the present invention.

[0046] Figure 4 It is an ablation degree positioning curve obtained by performing defect positioning on a specific defect positioning cable in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following further describes a method, system, and storage medium for locating ablation defects in a cable buffer layer according to the present invention in conjunction with specific embodiments and accompanying drawings.

[0048] A method for locating ablation defects of a cable buffer layer according to the present invention is as follows: Figure 1 The following steps are shown:

[0049] Step 1: Using the broadband impedance spectrum method, the input frequency range of the cable to be located for buffer layer ablation defect location is The broadband signal is used to obtain the real broadband impedance spectrum of the cable to be located. ;

[0050] Step 2: Create N simulated cables with the same length as the cable to be defect located; obtain simulated cable ablation degree sequences of the N simulated cables, and obtain simulated capacitance sequences of the N simulated cables through the N simulated cable ablation degree sequences;

[0051] The specific process of obtaining the simulated cable ablation degree sequence of N simulated cables is as follows: take n random numbers N times in the interval [0,1] and collect them to form the first sequence, the second sequence to the Nth sequence respectively, and define the first sequence, the second sequence to the Nth sequence as the first simulated cable ablation defect degree sequence of the first simulated cable, the second simulated cable to the Nth simulated cable in the N simulated cables. , the second simulated cable ablation defect degree sequence To the Nth simulated cable ablation defect degree sequence .

[0052] The specific process of obtaining the simulated capacitance sequence of N simulated cables is as follows: the first simulated cable ablation defect degree sequence , the second simulated cable ablation defect degree sequence To the Nth simulated cable ablation defect degree sequence Substitute the following formula (2) in sequence to calculate the first simulated capacitance sequence of the first simulated cable, the second simulated cable to the Nth simulated cable: , the second simulated capacitor sequence To the Nth analog capacitor sequence ,

[0053] (2)

[0054] In formula (2), is the e-th simulated capacitor sequence of the e-th simulated cable; is the capacitance sequence of a cable with the same length as the cable to be located and without defects, It is the defect degree sequence of the e-th simulated cable ablation degree of the e-th simulated cable.

[0055] Step 3: The N simulated cable ablation degree sequences and N simulated capacitance sequences of the N simulated cables are used as the initial population. The initial population is fitted with the cables to be defect located using a genetic algorithm to obtain an optimal population that is closest to the cables to be defect located. The N simulated cables represented by the N simulated cable ablation degree sequences and simulated capacitance sequences in the optimal population are used as the N simulated cables for defect location.

[0056] The specific fitting process in step 3 is as follows Figure 2 Shown, including:

[0057] Step 3.1: Initialize the number of fitting times i so that the number of fitting times i is equal to 1; use the initial population as the first population when the number of fitting times i is equal to 1;

[0058] Step 3.2: Input the N simulated cables in the first group in turn. Frequency of range changes And the first judgment broadband impedance spectrum from the first simulation cable to the Nth simulation cable in the first population is obtained by the principle of formula (3): To the Nth judgment broadband impedance spectrum ;

[0059] Step 3.3: Take the first judgment broadband impedance spectrum of the first population To the Nth judgment broadband impedance spectrum and true broadband impedance spectrum Substitute into the following formula (4) to calculate the N residual values ​​between the first population and the cable to be located ,

[0060] (4)

[0061] In formula (4), is the e-th judgment broadband impedance spectrum among the N judgment broadband impedance spectra; yes and The residual value between

[0062] If the N residual values ​​between the first population and the cable to be located are all less than the residual judgment threshold , then the first population is output as the optimal population, the fitting is stopped, and the following step 3.4 is executed;

[0063] If the N residual values ​​between the first group and the cable to be located are not less than the residual judgment threshold In the case of , the fitting times i is increased by 1, and the simulated cable ablation degree sequences of the N simulated cables in the first population are updated in sequence by the following formula (5), and the simulated cable ablation degree sequences of the N simulated cables when the fitting times i is equal to 2 are obtained.

[0064] (5)

[0065] In formula (5), It is the crossover mutation update operator in the genetic algorithm; and are the simulated cable ablation degree sequences of the e-th simulated cable of the N simulated cables before and after the update;

[0066] The simulated cable ablation degree sequence of the N simulated cables when the fitting number i is equal to 2 is calculated using the principle of formula (2) to obtain the simulated capacitance sequence of the N simulated cables when the fitting number i is equal to 2; the simulated cable ablation degree sequence and the simulated capacitance sequence of the N simulated cables when the fitting number i is equal to 2 are used as the second population, and the following step 3.4 is continued;

[0067] Step 3.4: Replace the population obtained in step 3.3 with the population in step 3.2 and repeat steps 3.2 to 3.3 until the optimal population is obtained;

[0068] Step 3.5: The N simulated cables represented by the N simulated cable ablation degree sequences and simulated capacitance sequences in the optimal population obtained in step 3.4 are used as N defect location simulated cables.

[0069] Step 4: Use transmission line theory to simulate N defect location simulation cables to obtain N simulated broadband impedance spectra of the N defect location simulation cables; subtract the N simulated broadband impedance spectra from the true broadband impedance spectrum in turn, and use the simulated cable ablation degree sequence of the defect location simulation cable corresponding to the simulated broadband impedance spectrum with the smallest difference as the cable ablation degree sequence of the cable to be defect located;

[0070] The specific process of obtaining the simulated broadband impedance spectrum of N defect location simulation cables in step 4 is as follows: input the N defect location simulation cables into Frequency of range changes , N simulated broadband impedance spectra are obtained by the following formula (3):

[0071] (3)

[0072] In formula (3), is the simulated broadband impedance spectrum of the e-th defect location simulation cable among the N defect location simulation cables; The simulated capacitance sequence of the e-th defect location simulated cable; It is the imaginary part in the process of simulating broadband impedance spectrum; 、 and It is the resistance series, inductance series, and conductance series of a cable with the same length as the cable to be located and without defects.

[0073] Step 5: Use cubic spline interpolation method to form transition segments between n cable ablation degree values ​​in the cable ablation degree sequence to obtain the ablation degree location curve of the defect location simulation cable. , as shown in the following formula (1),

[0074] (1)

[0075] In formula (1), are the difference coefficients obtained by cubic spline interpolation method;

[0076] Select the ablation degree positioning curve Greater than the ablation defect judgment threshold The position is the location where the buffer layer ablation defect occurs in the cable to be located.

[0077] Next, we will locate the buffer layer ablation defect of a specific cable to be defect-located.

[0078] In the first step, for a 3000m cable, a broadband impedance spectroscopy method is used. A sine wave voltage signal with a frequency range of 9kHz–200MHz and a number of 10,000 points is input. The instrument calculates the overall wave impedance spectrum of the tested product based on the amplitude and phase of the collected reflected voltage signal. ;

[0079] In the second step, 100 random numbers are taken 20 times in the interval [0,1] and collected to form the first sequence, the second sequence to the 20th sequence, which are used as the damage ablation defect degree sequence of 20 simulated cables (each divided into 100 segments). , and calculate its corresponding virtual capacitance using the following formula, and use it as the initial population (first generation population):

[0080]

[0081] The third step, such as Figure 3 As shown, the 9kHz-200MHz impedance spectra of the above 20 virtual cables are simulated and calculated using COMSOL transmission line theory, and the first judgment broadband impedance spectrum of the first simulated cable to the 20th simulated cable in the first group is obtained. To the Nth judgment broadband impedance spectrum .

[0082] The first judgment broadband impedance spectrum of the first population To the Nth judgment broadband impedance spectrum and true broadband impedance spectrum Substitute into the following formula (4) to calculate the 20 residual values ​​between the first population and the cable to be located , using the residual value as the objective function and the first population as the initial population. This population was then entered into a genetic algorithm program in Matlab. The population size was set to 20. The tournament method was used for selection, single-point crossover with a probability of 0.01 was used for crossover, and single-point reversal mutation with a probability of 0.05 was used for mutation. The algorithm was then executed, with the termination condition set to the objective function, i.e., the residual value was less than or equal to 50. The genetic algorithm was executed, with the program continuously performing selection, crossover, and mutation operations, with continuous updates, until the algorithm automatically terminated.

[0083] In the fourth step, the objective function of the population is finally obtained and the group with the smallest residual value is selected as the final fitting result, which is the optimal cable selection result.

[0084] The fifth step is to use the cubic spline interpolation method to form a transition segment between the 100 cable ablation degree values ​​in the cable ablation degree sequence to obtain the ablation degree positioning curve of the defect location simulation cable. , end fitting curve as Figure 4 shown.

[0085] The specific description of the cable buffer layer ablation defect positioning system of the present invention is as follows:

[0086] A cable buffer layer ablation defect positioning system can be used to implement the above-mentioned cable buffer layer ablation defect positioning method. Specifically, the cable buffer layer ablation defect positioning system includes:

[0087] A real broadband impedance spectrum acquisition module is used to obtain the real broadband impedance spectrum of the cable to be defect-located;

[0088] A simulated cable generation module is used to generate a simulated cable with the same length as the cable with defect location and obtain physical parameters of the simulated cable;

[0089] A defect location simulation cable generation module is used to fit the simulation cable with the defect location cable to obtain the defect location simulation cable;

[0090] The ablation defect location module locates the degree of ablation defects of the defect location cable through the defect location simulation cable.

[0091] All relevant contents of each step involved in the embodiment of the cable buffer layer ablation defect positioning method can be referred to the functional description of the functional modules corresponding to the cable buffer layer ablation defect positioning system in the embodiment of the present invention, and will not be repeated here.

[0092] The module division of the present invention is illustrative and represents only a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in various embodiments of the present invention may be integrated into a single processor, exist physically separately, or two or more modules may be integrated into a single module. The integrated modules may be implemented in either hardware or software form.

[0093] The present invention also provides a storage medium, specifically a computer-readable storage medium (Memory). This computer-readable storage medium is a memory device within a computer device, used to store programs and data. It is understood that the computer-readable storage medium herein may include both built-in storage media within the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides storage space, which stores the terminal's operating system. Furthermore, this storage space stores one or more instructions suitable for being loaded and executed by a processor. These instructions may be one or more computer programs (including program code). It should be noted that the computer-readable storage medium herein may be high-speed RAM memory or non-volatile memory, such as at least one disk drive. The processor may load and execute the one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the cable buffer layer ablation defect locating method described in the above-mentioned embodiment.

[0094] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0095] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0096] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1A step that specifies a function in one or more boxes.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for locating ablation defects in a cable buffer layer, characterized in that: The following steps are involved: Step 1: Using the broadband impedance spectrum method, the input frequency range of the cable to be located for buffer layer ablation defect location is The broadband signal is obtained to obtain the real broadband impedance spectrum of the cable to be defect-located. ; Step 2: Establish N simulated cables of the same length as the cable to be defect located; obtain simulated cable ablation degree sequences of the N simulated cables, and obtain simulated capacitance sequences of the N simulated cables through the N simulated cable ablation degree sequences; Step 3: Fitting the simulated cable ablation degree sequence and the simulated capacitance sequence to the cable to be defect located by a genetic algorithm to obtain N simulated cables for defect location; Step 4: Simulate N defect location simulation cables using transmission line theory and process the simulation results to obtain a cable ablation degree sequence of the cable to be defect located; Step 5: Use cubic spline interpolation method to form transition segments between n cable ablation degree values ​​in the cable ablation degree sequence to obtain the ablation degree location curve of the defect location simulation cable. , as shown in the following formula (1), （1） In formula (1), are the difference coefficients obtained by cubic spline interpolation method; n and N are natural numbers; Select the ablation degree positioning curve Greater than the ablation defect judgment threshold The position is the position where the buffer layer ablation defect occurs in the cable to be defect located.

2. The positioning method according to claim 1, wherein: The specific process of obtaining the simulated cable ablation degree sequence of N simulated cables in step 2 is as follows: take n random numbers N times in the interval [0, 1] and collect them respectively to form the first sequence, the second sequence to the Nth sequence, and define the first sequence, the second sequence to the Nth sequence as the first simulated cable ablation defect degree sequence of the first simulated cable, the second simulated cable to the Nth simulated cable in the N simulated cables. , the second simulated cable ablation defect degree sequence To the Nth simulated cable ablation defect degree sequence .

3. The positioning method according to claim 1, wherein: The specific process of obtaining the simulated capacitance sequence of N simulated cables in step 2 is as follows: , the second simulated cable ablation defect degree sequence To the Nth simulated cable ablation defect degree sequence Substitute the following formula (2) in sequence to calculate the first simulated capacitance sequence of the first simulated cable, the second simulated cable to the Nth simulated cable: , the second simulated capacitor sequence To the Nth analog capacitor sequence , （2） In formula (2), is the e-th simulated capacitor sequence of the e-th simulated cable; is the capacitance sequence of a cable with the same length as the cable to be located and without defects, It is the defect degree sequence of the e-th simulated cable ablation degree of the e-th simulated cable.

4. The positioning method according to claim 1, wherein: The specific process of simulating N defect location simulation cables using transmission line theory in step 4 is as follows: Frequency of range changes , N simulated broadband impedance spectra are obtained by the following formula (3): （3） In formula (3), is the simulated broadband impedance spectrum of the e-th defect location simulation cable among the N defect location simulation cables; The simulated capacitance sequence of the e-th defect location simulated cable; is the imaginary part in the process of simulating broadband impedance spectroscopy; 、 and The resistance sequence, inductance sequence and conductance sequence of a cable with the same length as the cable to be located and without defects; The specific process of processing the simulation results in step 4 to obtain the cable ablation degree sequence of the cable to be defect located is as follows: N simulated broadband impedance spectra obtained by simulating N defect location simulated cables are sequentially subtracted from the real broadband impedance spectrum, and the simulated cable ablation degree sequence of the defect location simulated cable corresponding to the simulated broadband impedance spectrum with the smallest difference is used as the cable ablation degree sequence of the cable to be defect located.

5. The positioning method according to claim 4, wherein: The specific fitting process in step 3 is as follows: Step 3.1: Initializing the fitting number i so that the fitting number i is equal to 1; using the N simulated cable ablation degree sequences and the N simulated capacitance sequences of the N simulated cables as the first population when the fitting number i is equal to 1; Step 3.2: Input the N simulated cables in the first group in turn. Frequency of range changes And the first judgment broadband impedance spectrum from the first simulation cable to the Nth simulation cable in the first population is obtained by the principle of formula (3): To the Nth judgment broadband impedance spectrum ; Step 3.3: performing residual update on the first population to obtain an updated population; Step 3.4: Replace the population in step 3.2 with the population obtained in step 3.3 and repeat steps 3.2 to 3.3 until the fitting stops; Step 3.5: Define the population obtained in steps 3 and 4 as the optimal population, and use the N simulated cables represented by the N simulated cable ablation degree sequences and simulated capacitance sequences in the optimal population as N defect location simulated cables.

6. The positioning method according to claim 5, wherein: The residual update process of step 3.3 is as follows: The first judgment broadband impedance spectrum of the first population To the Nth judgment broadband impedance spectrum and the real broadband impedance spectrum Substitute into the following formula (4) to calculate and obtain N residual values ​​between the first population and the cable to be defect-located, （4） In formula (4), is the e-th judgment broadband impedance spectrum among the N judgment broadband impedance spectra; is the With the The residual value between If the N residual values ​​between the first population and the cable to be located are all less than the residual judgment threshold , then the first population is output as the optimal population and fitting is stopped; If the N residual values ​​between the first population and the cable to be located are not less than the residual judgment threshold In the case of , the fitting times i is increased by 1, and the simulated cable ablation degree sequences of the N simulated cables in the first population are updated in sequence by the following formula (5), and the simulated cable ablation degree sequences of the N simulated cables when the fitting times i is equal to 2 are obtained. （5） In formula (5), is the crossover mutation update operator in the genetic algorithm; and are the simulated cable ablation degree sequences of the e-th simulated cable of the N simulated cables before and after the update; The simulated cable ablation degree sequence of the N simulated cables when the fitting number i is equal to 2 is calculated using the principle of formula (2) to obtain the simulated capacitance sequence of the N simulated cables when the fitting number i is equal to 2; the simulated cable ablation degree sequence and the simulated capacitance sequence of the N simulated cables when the fitting number i is equal to 2 are used as the second population, and step 3.4 is continued.

7. A cable buffer layer ablation defect positioning system equipped with the positioning method according to claim 1, characterized in that: include: The real broadband impedance spectrum acquisition module inputs a broadband signal to the cable to be located for buffer layer ablation defect location, and acquires the real broadband impedance spectrum of the cable to be located; A simulated cable generation module generates a simulated cable with the same length as the cable with defect location and obtains the physical parameters of the simulated cable; A defect location simulation cable generation module is used to fit the simulation cable with the cable to be defect located to obtain the defect location simulation cable; The ablation defect location module locates the degree of ablation defects of the defect location cable through the defect location simulation cable.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for locating ablation defects of a cable buffer layer as claimed in any one of claims 1 to 6 are implemented.

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