Insulation structure deterioration degree evaluation method based on dielectric constant and related equipment

Abstract

The embodiment of the invention discloses a dielectric constant-based insulation structure deterioration degree evaluation method and related equipment, and relates to the technical field of cable quality detection, a scattering vector is obtained according to a first dielectric constant, a second dielectric constant and scattering intensity, the coupling influence of interface phase thickness change and material deterioration is effectively decoupled, and the evaluation accuracy is improved. The optimal interface phase thickness parameter is screened through scattering intensity and scattering vector optimization, and the optimal interface phase thickness parameter can accurately represent the microstructure degradation state of cable insulation, so that the structure degradation degree of the cable insulation material to be evaluated is evaluated by using the optimal interface phase thickness parameter. And the degradation condition of the cable insulation material can be accurately reflected.

Description

Technical Field

[0001] The present invention relates to the technical field of cable quality detection, and in particular to a dielectric constant-based insulation structure degradation degree assessment method and related equipment. Background Art

[0002] The interfacial thickness of cable insulation materials is a key parameter affecting their electrical performance and mechanical stability. Traditional testing methods, such as microscopic observation or ultrasonic measurement, struggle to accurately characterize interfacial thickness and its degradation at the micro- and nanoscale. This is particularly true when the dielectric constant of cable insulation changes or microstructural damage due to long-term operation. Existing technologies cannot effectively distinguish the coupled effects of interfacial thickness changes and material degradation, leading to significant errors in the assessment results. Summary of the Invention

[0003] In view of this, the present invention provides a method for evaluating the degree of insulation structure degradation based on dielectric constant and related equipment.

[0004] The specific technical solution of the first embodiment of the present invention is: a method for evaluating the degree of insulation structure degradation based on dielectric constant, the method comprising: performing a small-angle scattering experiment on the cable insulation material to be evaluated to obtain the scattering intensity of the cable insulation material to be evaluated; obtaining the first dielectric constant of the first interface layer of the cable insulation material to be evaluated, and the second dielectric constant of the second interface layer of the standard cable insulation material that has not been degraded; obtaining a scattering vector of the scattering intensity based on the first dielectric constant, the second dielectric constant and the scattering intensity; selecting an optimal interface phase thickness parameter from multiple preset interface phase thickness parameters based on the scattering intensity and the scattering vector; the optimal interface phase thickness parameter is the actual interface phase thickness parameter of the cable insulation material to be evaluated; the interface phase thickness parameter is the thickness of the transition region between the crystalline phase and the adjacent amorphous phase of the cable insulation material; and evaluating the degree of structural degradation of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter.

[0005] Preferably, the scattering vector of the scattering intensity is obtained using the following formula:

[0006] in, is the scattering intensity, For the first interface layer at position The first dielectric constant at the interface layer and the second dielectric constant at the interface layer The difference in the second dielectric constant, is an imaginary number, is the scattering vector.

[0007] Preferably, selecting the optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters based on the scattering intensity and the scattering vector includes: constructing a first relationship curve between the scattering intensity, the scattering vector and the interface phase thickness parameter of the cable insulation material to be evaluated; and determining the optimal interface phase thickness parameter among the different preset interface phase thickness parameters using different preset interface phase thickness parameters, the first relationship curve and a preset scattering vector range.

[0008] Preferably, the method of using different preset interface phase thickness parameters, the first relationship curve and the preset scattering vector range to determine the optimal interface phase thickness parameter among the different preset interface phase thickness parameters includes: correcting the first relationship curve using different preset interface phase thickness parameters to obtain a second relationship curve corresponding to each preset interface phase thickness parameter; fitting the second relationship curve within the preset scattering vector range to obtain a fitting straight line for each second relationship curve; and determining the optimal interface phase thickness parameter based on the fitting straight line and the second relationship curve.

[0009] Preferably, the preset scattering vector range is obtained by the following method: obtaining a scattering vector range corresponding to the structure at the microscopic level of the cable insulation material to be evaluated; and the square value of the scattering vector range constitutes the preset scattering vector range.

[0010] Preferably, the first relationship curve is obtained using the following formula:

[0011] in, is a preset constant, is the correlation distance, which is a measure of the heterogeneity of a two-phase system. is the interface phase thickness parameter, is the scattering vector, is the scattering intensity.

[0012] Preferably, the evaluating the degree of structural degradation of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter includes: obtaining the transition interface phase thickness of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter; the transition interface phase thickness is the transition interface thickness from the crystalline region to the amorphous region of the cable insulation material to be evaluated; evaluating the degree of structural degradation of the cable insulation material to be evaluated based on the transition interface phase thickness and preset evaluation rules; wherein the preset evaluation rules include that the smaller the transition interface phase thickness, the more serious the degree of structural degradation of the cable insulation material to be evaluated, and the larger the transition interface phase thickness, the lighter the degree of structural degradation of the cable insulation material to be evaluated.

[0013] The specific technical solution of the second embodiment of the present invention is: a dielectric constant-based insulation structure degradation degree assessment system, the system comprising: a scattering intensity acquisition module, a dielectric constant acquisition module, a scattering vector acquisition module, an optimal selection module and an evaluation module; the scattering intensity acquisition module is used to perform a small-angle scattering experiment on the cable insulation material to be evaluated to obtain the scattering intensity of the cable insulation material to be evaluated; the dielectric constant acquisition module is used to obtain the first dielectric constant of the first interface layer of the cable insulation material to be evaluated, and the second dielectric constant of the second interface layer of the standard cable insulation material that has not been degraded; the scattering vector acquisition module is used to obtain a scattering vector of the scattering intensity based on the first dielectric constant, the second dielectric constant and the scattering intensity; the optimal selection module is used to select an optimal interface phase thickness parameter from multiple preset interface phase thickness parameters based on the scattering intensity and the scattering vector; the optimal interface phase thickness parameter is the actual interface phase thickness parameter of the cable insulation material to be evaluated; the interface phase thickness parameter is the thickness of the transition region between the crystalline phase and the adjacent amorphous phase of the cable insulation material; and the evaluation module is used to evaluate the structural degradation degree of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter.

[0014] The specific technical solution of the third embodiment of the present invention is: a device for evaluating the degree of degradation of an insulation structure based on dielectric constant, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method described in any one of the first embodiments of the present application.

[0015] The specific technical solution of the fourth embodiment of the present invention is: a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the method described in any one of the first embodiments of the present application.

[0016] The implementation of the present invention will have the following beneficial effects: The present invention obtains the scattering intensity through a small-angle scattering experiment, and derives the scattering vector by combining the first dielectric constant of the insulating material to be evaluated with the second dielectric constant of the standard insulating material, and selects the optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters according to the scattering intensity and the scattering vector, and evaluates the degree of structural degradation of the cable insulation material to be evaluated according to the optimal interface phase thickness parameter. Different degrees of degradation result in different structures and interface phase thicknesses of the materials, resulting in different dielectric constants and scattering intensities. Therefore, the scattering vector is obtained according to the first dielectric constant, the second dielectric constant and the scattering intensity, and the coupling effect of the interface phase thickness change and the material degradation is effectively decoupled. The optimal interface phase thickness parameter is optimized and screened by the scattering intensity and the scattering vector. The optimal interface phase thickness parameter can accurately characterize the microstructural degradation state of the cable insulation. Therefore, the optimal interface phase thickness parameter is used to evaluate the degree of structural degradation of the cable insulation material to be evaluated, which can accurately reflect the degradation of the cable insulation material. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 A flowchart of the steps of a method for evaluating the degree of insulation structure degradation based on dielectric constant; Figure 2 Schematic diagram of the scattering intensity curve of cable insulation materials after different heat treatment times; Figure 3 is a schematic diagram of a second relationship curve after correction of a cable insulation material that has not been heat-treated; Figure 4 A schematic diagram of a second relationship curve after correction of cable insulation materials subjected to different heat treatment times; Figure 5 Schematic diagram of the thickness change of the transition interface from the crystalline region to the amorphous region of the cable insulation material at different heat treatment stages; Figure 6 The schematic diagram of the insulation structure degradation degree assessment system based on dielectric constant; Among them, 201 is a scattering intensity acquisition module; 202 is a dielectric constant acquisition module; 203 is a scattering vector acquisition module; 204 is an optimal selection module; and 205 is an evaluation module. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] The terms "first," "second," and the like in the specification, claims, and drawings of this application are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or modules is not limited to the listed steps or modules but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to the process, method, product, or apparatus.

[0021] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] See also Figure 1 , is a flowchart of a method for evaluating the degree of insulation structure degradation based on dielectric constant in the first embodiment of the present application, which can accurately reflect the degradation of cable insulation materials. The method includes: Step 101: Perform a small-angle scattering experiment on the cable insulation material to be evaluated to obtain the scattering intensity of the cable insulation material to be evaluated; Step 102: Obtain a first dielectric constant of a first interface layer of the cable insulation material to be evaluated, and a second dielectric constant of a second interface layer of a standard cable insulation material that has not been degraded; Step 103: Obtain a scattering vector of the scattering intensity according to the first dielectric constant, the second dielectric constant, and the scattering intensity; Step 104: selecting an optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters based on the scattering intensity and the scattering vector; the optimal interface phase thickness parameter is an actual interface phase thickness parameter of the cable insulation material to be evaluated; the interface phase thickness parameter is a thickness of a transition region between a crystalline phase and an adjacent amorphous phase of the cable insulation material; Step 105: Evaluate the structural degradation degree of the cable insulation material to be evaluated according to the optimal interface phase thickness parameter.

[0023] Specifically, the cable insulation material to be evaluated is tested using a small-angle scattering experimental technique to accurately obtain its scattering intensity distribution data. The first dielectric constant of the cable insulation material to be evaluated is simultaneously collected, and the second dielectric constant of a standard cable insulation material that has not degraded is obtained. A scattering vector is obtained based on the scattering intensity data and the first and second dielectric constants. The optimal interface phase thickness parameter is selected from multiple preset interface phase thickness parameters based on the scattering vector and scattering intensity. The optimal thickness parameter is compared and analyzed with the interface phase thickness of the standard cable insulation material. If the thickness parameter deviates significantly from the standard value, it indicates that the cable insulation material to be evaluated has degraded interface layer structure. This method selects the optimal parameter from multiple preset interface phase thickness parameters based on the scattering intensity and scattering vector. This method combines experimental data with theoretical models, making the determined optimal interface phase thickness parameter closer to actual conditions.

[0024] The method in this embodiment obtains the scattering intensity through a small-angle scattering experiment, and derives the scattering vector by combining the first dielectric constant of the insulating material to be evaluated with the second dielectric constant of the standard insulating material, and selects the optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters based on the scattering intensity and the scattering vector, and evaluates the degree of structural degradation of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter. Different degrees of degradation result in different structures and interface phase thicknesses of the materials, resulting in different dielectric constants and scattering intensities. Therefore, the scattering vector is obtained based on the first dielectric constant, the second dielectric constant and the scattering intensity, effectively decoupling the coupling effects of the interface phase thickness change and material degradation. The optimal interface phase thickness parameter is optimized and screened by the scattering intensity and the scattering vector. The optimal interface phase thickness parameter can accurately characterize the microstructural degradation state of the cable insulation. Therefore, the use of the optimal interface phase thickness parameter to evaluate the degree of structural degradation of the cable insulation material to be evaluated can accurately reflect the degradation of the cable insulation material.

[0025] In a specific embodiment, the scattering vector of the scattering intensity is obtained using the following formula:

[0026] in, is the scattering intensity, For the first interface layer at position The first dielectric constant at the interface layer and the second dielectric constant at the interface layer The difference in the second dielectric constant, is an imaginary number, is the scattering vector. Specifically, based on the first interface layer at position The first dielectric constant at the interface layer and the second dielectric constant at the interface layer The difference in the second dielectric constant and other parameters can more accurately calculate the scattering vector related to the interface phase thickness, which helps to extract information related to the key structural parameter of the interface phase thickness from the complex scattering signal, and thus lay the foundation for determining the optimal interface phase thickness parameter.

[0027] In a specific embodiment, selecting the optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters based on the scattering intensity and the scattering vector includes: constructing a first relationship curve between the scattering intensity, the scattering vector and the interface phase thickness parameter of the cable insulation material to be evaluated; and determining the optimal interface phase thickness parameter among the different preset interface phase thickness parameters using different preset interface phase thickness parameters, the first relationship curve and a preset scattering vector range.

[0028] Specifically, construct the scattering intensity I ( q ), scattering vector q Interface phase thickness parameters of the cable insulation material to be evaluated The first relationship curve between them; starting from 0 and gradually taking different value, and calibrate the first relationship curve within the preset scattering vector range to determine the optimal interface phase thickness parameter , the structural degradation degree of the cable insulation material to be evaluated is evaluated based on the optimal interface phase thickness parameter.

[0029] In a specific embodiment, the method of using different preset interface phase thickness parameters, the first relationship curve, and a preset scattering vector range to determine the optimal interface phase thickness parameter among the different preset interface phase thickness parameters includes: correcting the first relationship curve using different preset interface phase thickness parameters to obtain a second relationship curve corresponding to each preset interface phase thickness parameter; fitting the second relationship curve within the preset scattering vector range to obtain a fitting straight line for each second relationship curve; and determining the optimal interface phase thickness parameter based on the fitting straight line and the second relationship curve.

[0030] Specifically, the first relationship curve is corrected. The correction method is: starting from 0 and gradually taking different Different second relationship curves are obtained, and the obtained second relationship curves are linearly fitted at the preset interface phase thickness parameters. When the standard deviation of the linear fitting is the smallest, the optimal interface phase thickness parameter is obtained. .

[0031] In a specific embodiment, the crystal structure of the insulating material is characterized by Linear fitting is performed on the value segment to obtain different The fitting line of the corresponding second relationship curve is traversed through all preset interface phase thickness parameters. The second relationship curve with the smallest standard deviation is selected as the optimal relationship curve. The corresponding target preset interface phase thickness parameter is the actual interface phase thickness parameter of the cable insulation material to be evaluated. If multiple candidate parameters have similar standard deviations, a scattering intensity gradient consistency constraint is further introduced (for example, the scattering intensity gradient ∇I(q) deviates from the theoretical gradient by less than 10%). By using the scattering vector range constraint and goodness of fit evaluation, the impact of noise interference on thickness parameter inversion is effectively reduced, improving the robustness and accuracy of interface phase thickness screening.

[0032] In a specific embodiment, the preset scattering vector range is obtained by: obtaining a scattering vector range corresponding to the structure at the microscopic level of the cable insulation material to be evaluated; and the square value of the scattering vector range constitutes the preset scattering vector range.

[0033] Specifically, cable insulation materials of different materials have significant differences in microstructure. By first determining the cable insulation material to be evaluated, then obtaining the corresponding scattering vector range based on the material microstructure, and using the square value of the range to form a preset scattering vector range, this method fully considers the influence of material properties on the scattering vector, so that the preset scattering vector range is closely related to the actual characteristics of the cable to be evaluated.

[0034] In a specific embodiment, the first relationship curve is obtained using the following formula:

[0035] in, is a preset constant, is the correlation distance, which is a measure of the heterogeneity of a two-phase system. is the interface phase thickness parameter, is the scattering vector, is the scattering intensity.

[0036] Specifically, by scattering vector and scattering intensity The coupling relationship between the interface phase thickness parameter The interface phase thickness heterogeneity parameter is directly correlated with the scattering experimental data, achieving quantitative inversion from scattering signals to microstructure parameters, breaking through the limitations of traditional methods that rely solely on empirical comparisons. Introduced The attenuation effect on the scattering intensity can effectively suppress high frequency noise (large q The interference of the value area) on the thickness inversion is improved under the condition of low signal-to-noise ratio. As a measure of the heterogeneity of the microstructure of the interface layer, the term and scattering vector The quadratic correlation can sensitively capture the spatial correlation of electron density fluctuations within the interface phase, providing key information for evaluating the degree of degradation of insulating materials (such as local defects or uneven aging). It can be flexibly adjusted to adapt to the microstructural regularity of different cable materials (such as polyethylene, cross-linked polyethylene, etc.), making the formula universal and at the same time calibrated by experiments and The accuracy of thickness screening can be further optimized.

[0037] In a specific embodiment, the evaluating the degree of structural degradation of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter includes: obtaining the transition interface phase thickness of the cable insulation material to be evaluated based on the optimal interface phase thickness parameter; the transition interface phase thickness is the transition interface thickness from the crystalline region to the amorphous region of the cable insulation material to be evaluated; evaluating the degree of structural degradation of the cable insulation material to be evaluated based on the transition interface phase thickness and preset evaluation rules; wherein the preset evaluation rules include that the smaller the transition interface phase thickness, the more serious the degree of structural degradation of the cable insulation material to be evaluated, and the larger the transition interface phase thickness, the lighter the degree of structural degradation of the cable insulation material to be evaluated.

[0038] Specifically, an intuitive quantitative evaluation metric was established by analyzing the positive correlation between the thickness of the transition interface phase and the degree of structural degradation. A decrease in the thickness of the transition interface phase indicates a blurred boundary between the crystalline and amorphous regions and increased segment disorder (e.g., due to crystalline damage caused by thermal aging or electrical stress), directly reflecting the intensification of microstructural degradation in the insulating material. Conversely, a greater thickness indicates a denser interface structure and greater crystalline integrity. This principle simplifies degradation diagnosis logic and avoids the complexity of traditional methods requiring comprehensive multi-parameter analysis.

[0039] Specifically, an embodiment of evaluating the degree of insulation structure degradation based on dielectric constant is as follows: 1. Sample preparation: In this embodiment, a 500kV cable insulation XLPE layer is selected as a sample, and an XLPE sample with a thickness of 0.2~0.4mm is obtained by ring cutting. The sample is placed in an ultrasonic cleaner filled with anhydrous ethanol and cleaned for 30 minutes, and then placed in a 60℃ oven to dry for 4 hours. Several samples are then selected and heat treated at 135℃ for 336h, 672h, 1008h and 1344h. Square samples with a width of about 10mm are cut from the sample for later use. The first dielectric constant of the first interface layer of the sample and the second dielectric constant of the second interface layer of the standard cable insulation material that has not been degraded are obtained.

[0040] 2. Perform X-ray scattering test on the sample: the test angle range is set to 0°~4°, and the wavelength of the double-slit collimated Cu-Kα X-ray source is λ=1.542 Å. The obtained scattering image is integrated after deducting the background scattering, and the scattering intensity vector is obtained using the first dielectric constant, the second node constant and the scattering intensity. Then the scattering vector is obtained. Scattering intensity The one-dimensional curve of Figure 2 As shown by Figure 2 It can be seen that with the increase of heat treatment time, the scattering intensity peak first increases and then decreases.

[0041] 3. Obtained scattering intensity The parameters are mathematically transformed to obtain the square of the scattering vector right The mathematical transformation is based on the Debye formula for small-angle scattering in the quasi-two-phase structure of semi-crystalline polymers to determine the scattering intensity. and the scattering vector Establish the following relationship:

[0042] 4. For the obtained The correction method is: starting from 0 and gradually taking different Worth different Curve, the obtained curve is used to characterize the XLPE crystal structure The linear fitting is performed on the value segment. When the standard deviation of the linear fitting is the smallest, the desired value. Figure 3 Shows the unheated XLPE test The corrected curve changes in the process from 2.24 to 2.30. The corrected curve is used to characterize the XLPE crystal structure. The linear fitting is performed in the range of 0.20 to 0.80, and the minimum standard deviation (root mean square error) of the fitting is determined. The standard deviation of the fitting is shown in Table 1. When it is 2.27, the error is the smallest, so this The value is the desired value.

[0043] Table 1: Standard deviation of the squares of different optimal interfacial phase thickness parameters for unheat-treated cable insulation

[0044] The same method was used to analyze the XLPE samples at different heat treatment stages. The curve is corrected to obtain the required Value, the result is Figure 4 As shown by Figure 4 It can be seen that after the curve is corrected, The linear relationship is more obvious in the range of 0.2-0.8.

[0045] 5. Calculate the thickness of the transition interface phase from the XLPE crystalline region to the amorphous region based on the obtained σ value , the calculation formula is as follows: .

[0046] The calculation results are as follows Figure 5 As shown in the figure, after a short period of heat treatment, the XLPE sample undergoes molecular chain recrystallization, causing some of the amorphous molecular chains to refold and arrange regularly into the crystalline region, resulting in an increase in the thickness of the transition interface. This also indicates that the arrangement of the XLPE molecular chains tends to become more regular in the early stages of heat treatment, and its microstructural quality has improved. Instead of deteriorating, it has improved. As the heat treatment time increases, the XLPE molecular chains are gradually destroyed, the crystalline structure defects gradually increase, the transition interface thickness gradually decreases, and the XLPE microstructure gradually deteriorates. Therefore, the degree of degradation of the XLPE microstructure can be accurately assessed based on the change in the transition interface thickness E value: The larger the value, the less severe the degradation of XLPE microstructure and the better the performance quality of XLPE; The smaller the value, the more serious the deterioration of the XLPE microstructure and the worse the performance quality.

[0047] In a specific embodiment, the second embodiment of the present application provides a structural schematic diagram of a dielectric constant-based insulation structure degradation degree evaluation system, the system comprising: a scattering intensity acquisition module 201, a dielectric constant acquisition module 202, a scattering vector acquisition module 203, an optimal selection module 204, and an evaluation module 205; the scattering intensity acquisition module 201 is used to perform a small-angle scattering experiment on the cable insulation material to be evaluated to obtain the scattering intensity of the cable insulation material to be evaluated; the dielectric constant acquisition module 202 is used to obtain the first dielectric constant of the first interface layer of the cable insulation material to be evaluated, and the second dielectric constant of the second interface layer of the standard cable insulation material that has not been degraded. constant; the scattering vector acquisition module 203 is used to obtain the scattering vector of the scattering intensity according to the first dielectric constant, the second dielectric constant and the scattering intensity; the optimal selection module 204 is used to select the optimal interface phase thickness parameter from multiple preset interface phase thickness parameters according to the scattering intensity and the scattering vector; the optimal interface phase thickness parameter is the actual interface phase thickness parameter of the cable insulation material to be evaluated; the interface phase thickness parameter is the thickness of the transition region between the crystalline phase and the adjacent amorphous phase of the cable insulation material; the evaluation module 205 is used to evaluate the degree of structural degradation of the cable insulation material to be evaluated according to the optimal interface phase thickness parameter.

[0048] The system in this embodiment obtains the scattering intensity through a small-angle scattering experiment, and derives the scattering vector by combining the first dielectric constant of the insulating material to be evaluated with the second dielectric constant of the standard insulating material. Based on the scattering intensity and the scattering vector, the optimal interface phase thickness parameter is selected from a plurality of preset interface phase thickness parameters, and the degree of structural degradation of the cable insulation material to be evaluated is evaluated based on the optimal interface phase thickness parameter. Different degrees of degradation result in different structures and interface phase thicknesses of the materials, resulting in different dielectric constants and scattering intensities. Therefore, the scattering vector is obtained based on the first dielectric constant, the second dielectric constant and the scattering intensity, effectively decoupling the coupling effects of the interface phase thickness change and material degradation. The optimal interface phase thickness parameter is optimized and screened by the scattering intensity and the scattering vector. The optimal interface phase thickness parameter can accurately characterize the microstructural degradation state of the cable insulation. Therefore, the use of the optimal interface phase thickness parameter to evaluate the structural degradation degree of the cable insulation material to be evaluated can accurately reflect the degradation of the cable insulation material.

[0049] In a specific embodiment, the third embodiment of the present application provides an insulation structure degradation degree assessment device based on dielectric constant, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described in any one of the first embodiments of the present application.

[0050] In a specific embodiment, the fourth embodiment of the present application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor performs the steps of the method described in any one of the first embodiments of the present application.

[0051] The above embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0052] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any person skilled in the art may utilize the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification, equivalent change, and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for evaluating the degree of insulation structure degradation based on dielectric constant, characterized in that: The method comprises: Performing a small-angle scattering experiment on the cable insulation material to be evaluated to obtain the scattering intensity of the cable insulation material to be evaluated; Obtaining a first dielectric constant of a first interface layer of the cable insulation material to be evaluated, and a second dielectric constant of a second interface layer of a standard cable insulation material that has not been degraded; Obtaining a scattering vector of the scattering intensity according to the first dielectric constant, the second dielectric constant, and the scattering intensity; selecting an optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters according to the scattering intensity and the scattering vector; the optimal interface phase thickness parameter is an actual interface phase thickness parameter of the cable insulation material to be evaluated; the interface phase thickness parameter is a thickness of a transition region between a crystalline phase and an adjacent amorphous phase of the cable insulation material; The structural degradation degree of the cable insulation material to be evaluated is evaluated according to the optimal interface phase thickness parameter.

2. The method for evaluating the degree of insulation structure degradation based on dielectric constant according to claim 1, wherein: The scattering vector of the scattering intensity is obtained using the following formula: in, is the scattering intensity, For the first interface layer at position The first dielectric constant at the interface layer and the second dielectric constant at the interface layer The difference in the second dielectric constant, is an imaginary number, is the scattering vector.

3. The method for evaluating the degree of insulation structure degradation based on dielectric constant according to claim 1, wherein: The selecting an optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters according to the scattering intensity and the scattering vector comprises: Constructing a first relationship curve between the scattering intensity, the scattering vector and an interface phase thickness parameter of the cable insulation material to be evaluated; By using different preset interface phase thickness parameters, the first relationship curve and a preset scattering vector range, an optimal interface phase thickness parameter is determined among the different preset interface phase thickness parameters.

4. The method for evaluating the degree of insulation structure degradation based on dielectric constant according to claim 3, wherein: The method of using different preset interface phase thickness parameters, the first relationship curve, and a preset scattering vector range to determine an optimal interface phase thickness parameter among the different preset interface phase thickness parameters includes: Correcting the first relationship curve using different preset interface phase thickness parameters to obtain a second relationship curve corresponding to each preset interface phase thickness parameter; Fitting the second relationship curve within a preset scattering vector range to obtain a fitting straight line for each second relationship curve; An optimal interface phase thickness parameter is determined based on the fitting straight line and the second relationship curve.

5. The method for evaluating the degree of insulation structure degradation based on dielectric constant according to claim 4, wherein: The preset scattering vector range is obtained by the following method: Obtaining a scattering vector range corresponding to the structure of the cable insulation material to be evaluated at a microscopic level; The square value of the scattering vector range constitutes the preset scattering vector range.

6. The method for evaluating the degree of insulation structure degradation based on dielectric constant according to claim 3, wherein: The first relationship curve is obtained using the following formula: in, is a preset constant, is the correlation distance, which is a measure of the heterogeneity of a two-phase system. is the interface phase thickness parameter, is the scattering vector, is the scattering intensity.

7. The method for evaluating the degree of insulation structure degradation based on dielectric constant according to claim 1, wherein: The evaluating the structural degradation degree of the cable insulation material to be evaluated according to the optimal interface phase thickness parameter includes: Obtaining the transition interface phase thickness of the cable insulation material to be evaluated according to the optimal interface phase thickness parameter; the transition interface phase thickness is the transition interface thickness from the crystalline region to the amorphous region of the cable insulation material to be evaluated; The degree of structural degradation of the cable insulation material to be evaluated is evaluated based on the thickness of the transition interface phase and preset evaluation rules; wherein the preset evaluation rules include that the smaller the thickness of the transition interface phase, the more severe the degree of structural degradation of the cable insulation material to be evaluated, and the larger the thickness of the transition interface phase, the lighter the degree of structural degradation of the cable insulation material to be evaluated.

8. A dielectric constant-based insulation structure degradation assessment system, characterized in that: The system includes: a scattering intensity acquisition module, a dielectric constant acquisition module, a scattering vector acquisition module, an optimal selection module and an evaluation module; The scattering intensity acquisition module is used to perform a small-angle scattering experiment on the cable insulation material to be evaluated to obtain the scattering intensity of the cable insulation material to be evaluated; The dielectric constant acquisition module is used to obtain a first dielectric constant of a first interface layer of the cable insulation material to be evaluated, and a second dielectric constant of a second interface layer of a standard cable insulation material that has not been degraded; The scattering vector acquisition module is used to obtain the scattering vector of the scattering intensity according to the first dielectric constant, the second dielectric constant and the scattering intensity; The optimal selection module is used to select an optimal interface phase thickness parameter from a plurality of preset interface phase thickness parameters according to the scattering intensity and the scattering vector; the optimal interface phase thickness parameter is the actual interface phase thickness parameter of the cable insulation material to be evaluated; the interface phase thickness parameter is the thickness of the transition region between the crystalline phase and the adjacent amorphous phase of the cable insulation material; The evaluation module is used to evaluate the structural degradation degree of the cable insulation material to be evaluated according to the optimal interface phase thickness parameter.

9. A device for evaluating the degree of insulation structure degradation based on dielectric constant, comprising a memory and a processor, characterized in that: The memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

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