Evaluation method and system for the ablation risk of buffer layer of high-voltage corrugated aluminum sheathed cables

Abstract

The present invention discloses a method and system for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable. The method comprises determining the buffer layer ablation starting temperature of the cable under test; measuring a first resistance value between the buffer layer and the aluminum sheath of the cable under test when the operating temperature of the buffer layer reaches the buffer layer ablation starting temperature; applying a test voltage using the buffer layer and the aluminum sheath of the cable under test as the positive and negative test electrodes, respectively, to measure a second resistance value between the buffer layer and the aluminum sheath of the cable under test; calculating the ratio of the second resistance value to the first resistance value to obtain a buffer layer ablation risk coefficient, and determining the relationship between the buffer layer ablation risk coefficient and a preset threshold value to determine whether the buffer layer of the cable under test has ablation risk. The present invention can accurately assess the ablation risk of the cable buffer layer.

Description

Technical Field

[0001] The present invention relates to the technical field of cable ablation risk assessment, and in particular to a method and system for assessing the ablation risk of a buffer layer of a high-voltage corrugated aluminum sheathed cable. Background Art

[0002] With the development of urban power grids and the increasing scarcity of land resources, high-voltage cables are becoming increasingly common. The insulation condition of these cables is directly related to the reliability and stability of the entire power network. However, in recent years, high-voltage cable buffer layer ablation failures have become frequent. This occurs on the semi-conductive buffer layer (referred to as the buffer layer) and white powder precipitates at the defects, gradually degrading the cable's main insulation and ultimately causing insulation breakdown. Buffer layer ablation defects are highly latent, develop over a long period of time, and have a wide impact range, severely impacting the safe operation of urban power transmission networks.

[0003] Current research on buffer layer ablation defects shows that the resistivity change of the damp semi-conductive water-resistant buffer layer strip leads to poor contact between the corrugated aluminum sheath and the insulating shielding layer, generating local electric field distortion at the contact point between the corrugated aluminum sheath trough and the insulating shielding layer, and gradually deteriorating the main insulation of the high-voltage cable.

[0004] The current buffer layer ablation risk assessment method uses a fuzzy comprehensive assessment of the buffer layer's condition based on multiple assessment factors, such as the cable's buffer layer's volume resistivity and moisture content. Using a modified analytic hierarchy process (AHP), each assessment factor is weighted to assess the buffer layer's condition and, consequently, the risk of buffer layer ablation. This method involves numerous and complex assessment factors, and does not include an assessment of the contact state between the cable's aluminum sheath and the buffer layer. The resulting buffer layer condition assessment method is not directly related to buffer layer ablation, and therefore cannot accurately assess the risk of buffer layer ablation. Summary of the Invention

[0005] The present invention aims to solve the technical problems in the related art at least to a certain extent. To this end, the first object of the present invention is to provide a method for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable, which can accurately evaluate the ablation risk of the buffer layer.

[0006] The second object of the present invention is to provide a system for evaluating the risk of ablation of the buffer layer of a high-voltage corrugated aluminum sheathed cable.

[0007] A third object of the present invention is to provide a computer-readable storage medium.

[0008] A fourth object of the present invention is to provide an electronic device.

[0009] To achieve the above object, the present invention is implemented through the following technical solutions:

[0010] A method for evaluating the ablation risk of a buffer layer of a high-voltage corrugated aluminum sheathed cable comprises:

[0011] Determine the starting ablation temperature of the buffer layer of the cable under test;

[0012] Measuring a first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature;

[0013] The buffer layer and the aluminum sheath of the cable to be tested are used as the positive and negative electrodes of the test respectively, a test voltage is applied, and a second resistance value between the buffer layer and the aluminum sheath of the cable to be tested is measured;

[0014] The ratio of the second resistance value to the first resistance value is calculated to obtain a buffer layer ablation risk coefficient, and the relationship between the buffer layer ablation risk coefficient and a preset threshold is determined to determine whether the buffer layer of the cable under test has ablation risk.

[0015] Preferably, determining the buffer layer ablation starting temperature of the cable to be tested includes:

[0016] Taking the buffer layer of the cable to be tested of a preset length as a test sample, and recording the surface morphology of the test sample before heating;

[0017] Based on the set temperature gradient, the test piece is heated for a preset time in sequence, and after each heating is completed, the surface morphology of the test piece is compared with the surface morphology of the test piece before heating to determine the starting ablation temperature of the buffer layer of the cable to be tested.

[0018] Preferably, measuring a first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature includes:

[0019] Determine the resistivity of the buffer layer of the cable under test at different deformation distances;

[0020] Determine the current density and temperature field of the buffer layer under different interference fit distances and different numbers of poor contact points of the cable to be tested, and determine the interference fit distance and the number of poor contact points when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature based on the determined current density and temperature field of the buffer layer;

[0021] The first resistance value is determined based on the resistivity of the buffer layer of the cable to be tested at different deformation distances, the interference fit distance when the operating temperature of the buffer layer reaches the initial ablation temperature of the buffer layer, and the number of poor contact points.

[0022] Preferably, determining the current density and temperature field of the buffer layer of the cable under test at different interference fit distances and different numbers of poor contact points includes:

[0023] Obtaining the physical parameter values ​​of each layer of the cable to be tested, the physical parameters including at least relative dielectric constant, resistivity, thermal conductivity, constant pressure heat capacity, density and outer diameter parameters;

[0024] An electrothermal coupling field simulation model of the cable to be tested is established based on the physical parameter values ​​of each layer of the cable to be tested;

[0025] Obtaining the annual flow rate, ambient temperature, convection heat dissipation coefficient and voltage level parameters of the cable to be tested in order to determine the boundary conditions of the electrothermal coupling field simulation model;

[0026] The electrothermal coupling field simulation model is solved based on the boundary conditions to obtain the buffer layer current density and temperature field under different interference fit distances and different numbers of poor contact points of the cable to be tested.

[0027] Preferably, determining the resistivity of the buffer layer of the cable to be tested at different deformation distances includes:

[0028] Take a buffer layer of preset area and preset thickness as a sample;

[0029] applying pressure to the sample and recording the deformation distance of the sample;

[0030] The resistance values ​​of the sample at different deformation distances are measured to obtain the resistivity of the buffer layer of the cable to be tested at different deformation distances.

[0031] Preferably, the interference fit distance is the radial distance that the aluminum sheath of the cable to be tested is pressed into the buffer layer of the cable to be tested; the number of poor contact points is the number of troughs where the aluminum sheath of the cable to be tested is not in contact with the buffer layer of the cable to be tested.

[0032] Preferably, judging the relationship between the buffer layer ablation risk coefficient and a preset threshold value to determine whether the buffer layer of the cable to be tested has ablation risk includes:

[0033] When the buffer layer ablation risk coefficient is greater than a preset threshold, it is determined that the buffer layer of the cable under test has ablation risk; otherwise, it is determined that the buffer layer of the cable under test does not have ablation risk.

[0034] To achieve the above-mentioned object, the second aspect of the present invention provides a system for evaluating the risk of ablation of the buffer layer of a high-voltage corrugated aluminum sheathed cable, comprising:

[0035] A determination module, used to determine the starting ablation temperature of the buffer layer of the cable to be tested;

[0036] A first measuring module is used to measure a first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature;

[0037] A second measuring module is configured to use the buffer layer and the aluminum sheath of the cable to be tested as the positive and negative electrodes for testing, apply a test voltage, and measure a second resistance value between the buffer layer and the aluminum sheath of the cable to be tested;

[0038] a calculation module, configured to calculate a ratio of the second resistance value to the first resistance value to obtain a buffer layer ablation risk coefficient;

[0039] A judgment module, configured to judge the relationship between the buffer layer ablation risk coefficient and a preset threshold;

[0040] The evaluation module is used to determine whether the buffer layer of the cable to be tested has ablation risk based on the size relationship judgment result.

[0041] To achieve the above objectives, the third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the above-mentioned method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable is implemented.

[0042] To achieve the above-mentioned objectives, the fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the above-mentioned method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable is implemented.

[0043] The present invention has at least the following technical effects:

[0044] (1) The evaluation method proposed in the present invention has practical physical significance, rather than a combination of multiple evaluation factors through weights. Since the main reason for the ablation of the buffer layer of the wrinkled aluminum sheath is the poor electrical contact between the aluminum sheath and the buffer layer, the present invention accurately reflects the electrical contact state between the two by the resistance value between the two. By reaching the starting ablation temperature of the buffer layer, the electrical contact state is limited, and the limit value of the resistance value between the aluminum sheath and the buffer layer of the cable to be tested, that is, the buffer layer ablation risk coefficient, is obtained. The buffer layer ablation risk is evaluated in this way, which can improve the accuracy of the evaluation results.

[0045] (2) Traditional evaluation methods require multiple test items on the cable, which is complex and likely to cause certain damage to the cable. However, in actual engineering, the present invention only needs to measure the resistance value between the aluminum sheath and the buffer layer, which causes less damage to the cable under test. Therefore, the present invention is simple to apply in actual engineering, causes less damage to the sample under test, and is economical. In addition, the evaluation method of the present invention only needs to measure the resistance value between the buffer layer and the aluminum sheath of the cable under test, which is easy to operate and has high reliability and repeatability.

[0046] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of a method for evaluating the ablation risk of a buffer layer of a high-voltage corrugated aluminum sheathed cable according to an embodiment of the present invention.

[0048] Figure 2 Schematic diagram of the structure of a cable to be tested according to an embodiment of the present invention.

[0049] Figure 3 FIG. 4 is a partial schematic diagram of a buffer layer of a cable to be tested according to an embodiment of the present invention.

[0050] Figure 4 Schematic diagram of a resistance calculation circuit model according to an embodiment of the present invention.

[0051] Figure 5 This is a simplified schematic diagram of a resistance calculation circuit model according to an embodiment of the present invention.

[0052] Figure 6 2 is a schematic diagram of a second resistance value test according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The present embodiment is described in detail below. Examples of the embodiment are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0054] The following describes the method and system for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable according to this embodiment with reference to the accompanying drawings.

[0055] Figure 1 Flow chart of the method for evaluating the risk of ablation of the buffer layer of a high-voltage corrugated aluminum sheathed cable according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0056] Step S1: determining the initial ablation temperature of the buffer layer of the cable to be tested.

[0057] In this embodiment, the structural diagram of the cable to be tested is as follows: Figure 2 As shown, the cable under test includes a conductor 1, a conductor shielding layer 2, an XLPE (cross-linked polyethylene) insulation layer 3, an insulation shielding layer 4, a buffer layer 5, a corrugated aluminum sheath 6, an air layer 7, and an outer sheath 8. It should be noted that this embodiment mainly determines the initial ablation temperature of the buffer layer.

[0058] In one embodiment of the present invention, determining the buffer layer ablation starting temperature of the cable to be tested includes:

[0059] Step S11: taking the buffer layer of a cable to be tested with a preset length as a test sample, and recording the surface morphology of the test sample before heating.

[0060] Step S12: Based on the set temperature gradient, the test piece is heated for a preset time in sequence, and after each heating is completed, the surface morphology of the test piece is compared with the surface morphology of the test piece before heating to determine the starting ablation temperature of the buffer layer of the cable to be tested.

[0061] Specifically, a predetermined length of the buffer layer used in the cable under test can be used as a test sample. The surface morphology of the buffer layer before ablation can be recorded. The sample is then heated in an oven at a temperature gradient of 5°C for 24 hours (a longer heating time is used because a short heating time does not produce significant changes in the buffer layer after ablation). The buffer layer's initial ablation temperature is then tested. The surface morphology of the heated buffer layer is recorded and compared with the surface morphology before heating to determine the initial ablation temperature of the buffer layer of the cable under test.

[0062] Step S2: measuring a first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer of the cable to be tested reaches the buffer layer starting ablation temperature.

[0063] In this embodiment, measuring a first resistance value between the buffer layer and the aluminum sheath of the cable under test when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature includes:

[0064] Step S21: determining the resistivity of the buffer layer of the cable to be tested at different deformation distances.

[0065] Among them, determining the resistivity of the buffer layer of the cable to be tested at different deformation distances includes: taking a buffer layer of a preset area and a preset thickness as a sample; applying pressure to the sample and recording the deformation distance of the sample; measuring the resistance value of the sample at different deformation distances, so as to obtain the resistivity of the buffer layer of the cable to be tested at different deformation distances.

[0066] Specifically, a buffer layer with a preset area of ​​S and a preset thickness of h1 can be used as a sample. A press is used to apply pressure to it, and a height gauge is used to measure its deformation distance x. A multimeter is used to measure its resistance value R(x) at different deformation distances. The deformation characteristics of the buffer layer resistivity are calculated based on the resistance value, sample size, and deformation distance. Its resistivity ρ(x) at different deformation distances is:

[0067]

[0068] Step S22: Determine the current density and temperature field of the buffer layer under different interference fit distances and different numbers of poor contact points of the cable to be tested, and determine the interference fit distance and the number of poor contact points when the buffer layer operating temperature reaches the buffer layer starting ablation temperature based on the determined buffer layer current density and temperature field.

[0069] Figure 3 It is a partial schematic diagram of the buffer layer of the cable to be tested. Figure 3 As shown, the interference fit distance is the radial distance x1 that the aluminum sheath of the cable to be tested is pressed into the buffer layer of the cable to be tested; the number of poor contact points is the number of troughs where the aluminum sheath of the cable to be tested is not in contact with the buffer layer of the cable to be tested, that is, the number of troughs in area 12.

[0070] In this embodiment, determining the current density and temperature field of the buffer layer of the tested cable under different interference fit distances and different numbers of poor contact points includes:

[0071] Step S221: obtaining the physical parameter values ​​of each layer of the cable to be tested, where the physical parameters at least include relative dielectric constant, resistivity, thermal conductivity, constant pressure heat capacity, density and outer diameter parameters.

[0072] Step S222: establishing an electrothermal coupling field simulation model of the cable to be tested based on the physical parameter values ​​of each layer of the cable to be tested.

[0073] Step S223: Obtain the annual flow rate, ambient temperature, convection heat dissipation coefficient and voltage level parameters of the cable to be tested, so as to determine the boundary conditions of the electrothermal coupling field simulation model.

[0074] Step S224: Solve the electrothermal coupling field simulation model based on the boundary conditions to obtain the current density and temperature field of the buffer layer under different interference fit distances and different numbers of poor contact points of the cable to be tested.

[0075] Specifically, the relative dielectric constant, resistivity, thermal conductivity, constant pressure heat capacity, density and outer diameter parameters of the physical layers of the cable conductor, conductor shield, XLPE insulation, insulation shield, buffer layer, aluminum sheath and outer sheath to be tested can be collected first, and then the electrothermal coupling field simulation model of a single contact point of the cable to be tested can be established. Furthermore, the annual flow rate, ambient temperature, convection heat dissipation coefficient and voltage level parameters of the cable to be tested can be collected as boundary conditions of the electrothermal coupling field simulation model. Afterwards, the buffer layer current density and temperature field of the electrothermal coupling field simulation model are calculated based on the boundary conditions to obtain the buffer layer current density and temperature field under different interference fit distances and different numbers of poor contact points, and the interference fit distance x1 and the number of poor contact points n when the operating temperature reaches the starting ablation temperature of the buffer layer are recorded.

[0076] Step S23: determining a first resistance value based on the resistivity of the tested cable buffer layer at different deformation distances, the interference fit distance when the operating temperature of the buffer layer reaches the initial ablation temperature of the buffer layer, and the number of poor contact points.

[0077] Specifically, a resistance calculation circuit model between the buffer layer and the aluminum sheath of the cable to be tested is established, as shown in FIG. Figure 4 As shown, the number of aluminum sheath nodes, that is, the total number of contact points, N = L / γ (L is the length of the cable to be tested, γ is the aluminum sheath pitch). In order to make the resistance value corresponding to the initial ablation temperature of the buffer layer more stringent, it is assumed that the good contact points are all close to the network port, that is, Figure 4 shown. Figure 4 In the equation, the total number of contact points is the one poor contact point on the right side of R1 plus the one good contact point on the right side of R3, so the total number of contact points N = 2. Of these, there is one poor contact point on the right side of R1, so n = 1. Therefore, the number of resistors R1 is N / 2 + n, or 2, and the number of resistors R2 is 2N, or 4. Therefore, the number of poor contact points n determines the number of resistors R1 in the resistance calculation circuit model, which in turn affects the equivalent resistance R.

[0078] Furthermore, based on the volume resistivity parameters of the buffer layer, the interference fit distance x1 between the buffer layer and the aluminum sheath, and the number of poor contact points n, the resistance values ​​of the resistors R1, R2, and R3 in the circuit are calculated, and then the equivalent resistance R of the local cable section is obtained.

[0079]

[0080]

[0081] l=l1-l2 (4)

[0082]

[0083]

[0084]

[0085] Among them, since the aluminum sheath is corrugated and can be similar to a sine function, Figure 2The horizontal axis represents the angle, so l1 and l2 are the coordinate values ​​of the two good contact points on the upper surface of the aluminum sheath and the buffer layer, which are expressed in angles; arcsin is the inverse sine function; h2 is the corrugation depth of the aluminum sheath; l is the axial distance of the aluminum sheath pressed into the buffer layer; R1 is the radial resistance of the part of the buffer layer that is not in contact with the aluminum sheath, R2 is the axial resistance between each contact point of the buffer layer, and R3 is the radial resistance of the part of the buffer layer in contact with the aluminum sheath; x is the deformation distance of the buffer layer; r is the distance from any point in the radial direction of the buffer layer to the insulating shielding layer; r1 and r2 are the outer diameters of the insulating shielding layer and the outer diameter of the buffer layer, respectively; ρ(x1) is the resistivity when the deformation distance is x1, and ρ(x=0) is the resistivity when the deformation distance is 0. Therefore, based on the resistance values ​​of resistors R1, R2 and R3, the equivalent circuit diagram can be used, i.e. Figure 4 The equivalent resistance R between the buffer layer and the aluminum sheath of the cable to be tested is obtained.

[0086] Furthermore, the resistance calculation circuit model is simplified, as shown in the following example: Figure 5 As shown, the network port resistance R after the Mth simplification M The network port resistance R after M-1 simplification M-1 The relationship between R M =(R M-1 +2R2) / / R3. Thus, based on the recursive relationship and the obtained interference fit distance x1 and the number of poor contact points n when the operating temperature reaches the buffer layer's initial ablation temperature, the first resistance value R0 between the aluminum sheath and the buffer layer of the entire cable under test when the operating temperature reaches the buffer layer's initial ablation temperature is obtained.

[0087] Step S3: using the buffer layer and the aluminum sheath of the cable to be tested as the positive and negative electrodes respectively, applying a test voltage, and measuring a second resistance value between the buffer layer and the aluminum sheath of the cable to be tested.

[0088] Figure 6 This is a schematic diagram for testing the second resistance value. Figure 6 As shown, the buffer layer and aluminum sheath of the cable to be tested are used as the positive and negative poles of the test respectively, and a multimeter is connected. The test voltage is slowly increased until it is sufficient to obtain a current reading, and a second resistance value R4 between the two is obtained.

[0089] Step S4: Calculate the ratio of the second resistance value to the first resistance value to obtain a buffer layer ablation risk coefficient, and determine the relationship between the buffer layer ablation risk coefficient and a preset threshold value to determine whether the buffer layer of the cable under test has ablation risk.

[0090] Among them, the relationship between the buffer layer ablation risk coefficient and the preset threshold is judged to determine whether the buffer layer of the cable under test has ablation risk, including: when the buffer layer ablation risk coefficient is greater than the preset threshold, it is determined that the buffer layer of the cable under test has ablation risk; otherwise, it is determined that the buffer layer of the cable under test does not have ablation risk.

[0091] Specifically, the buffer layer ablation risk coefficient, i.e., R4 / R0, is obtained by calculating the ratio of the second resistance value to the first resistance value. The larger the coefficient, for example, when it is greater than a preset threshold, the more likely the buffer layer is to be at risk of ablation. Conversely, the buffer layer of the cable to be tested is not likely to be at risk of ablation.

[0092] Therefore, the ablation risk assessment method proposed in this embodiment accurately reflects the electrical contact state between the buffer layer and the aluminum sheath, and physically assesses the ablation risk of the cable under test.

[0093] Furthermore, the present invention also provides a system for evaluating the ablation risk of a buffer layer of a high-voltage corrugated aluminum sheathed cable, comprising a determination module, a first measurement module, a second measurement module, a calculation module, a judgment module and an evaluation module connected in sequence.

[0094] Among them, the determination module is used to determine the starting ablation temperature of the buffer layer of the cable to be tested; the first measurement module is used to measure the first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer reaches the starting ablation temperature of the buffer layer; the second measurement module is used to use the buffer layer and the aluminum sheath of the cable to be tested as the positive and negative poles of the test respectively, apply the test voltage, and measure the second resistance value between the buffer layer and the aluminum sheath of the cable to be tested; the calculation module is used to calculate the ratio of the second resistance value to the first resistance value to obtain the buffer layer ablation risk coefficient; the judgment module is used to judge the size relationship between the buffer layer ablation risk coefficient and the preset threshold; the evaluation module is used to determine whether there is a ablation risk in the buffer layer of the cable to be tested based on the size relationship judgment result.

[0095] It should be noted that the specific implementation of the system for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable in an embodiment of the present invention can refer to the specific implementation of the method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable mentioned above. To avoid redundancy, it will not be repeated here.

[0096] In summary, the evaluation method proposed in the present invention has practical physical significance, rather than a combination of multiple evaluation factors through weights. Since the main reason for the ablation of the buffer layer of the corrugated aluminum sheath is the poor electrical contact between the aluminum sheath and the buffer layer, the present invention accurately reflects the electrical contact state between the two by the resistance value between the two. By reaching the starting ablation temperature of the buffer layer, the electrical contact state is limited, and the limit of the resistance value between the aluminum sheath and the buffer layer of the cable to be tested, that is, the buffer layer ablation risk coefficient, is obtained. In this way, the buffer layer ablation risk is evaluated, which can improve the accuracy of the evaluation results. In addition, the traditional method requires multiple test items to be performed on the cable during evaluation, the process is complicated, and it is easy to cause certain damage to the cable. However, in actual engineering, the present invention only needs to measure the resistance value between the aluminum sheath and the buffer layer, which has little damage to the cable to be tested. Therefore, the present invention is simple to apply in actual engineering, has little damage to the sample to be tested, and is economical. In addition, the evaluation method of the present invention only needs to detect the resistance value between the buffer layer and the aluminum sheath of the cable to be tested, which is easy to operate and has high reliability and repeatability.

[0097] Furthermore, the present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the above-mentioned method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable is implemented.

[0098] Furthermore, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the above-mentioned method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable is implemented.

[0099] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0100] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable, characterized in that: include: Determine the starting ablation temperature of the buffer layer of the cable under test; Measuring a first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature; The buffer layer and the aluminum sheath of the cable to be tested are used as the positive and negative electrodes of the test respectively, a test voltage is applied, and a second resistance value between the buffer layer and the aluminum sheath of the cable to be tested is measured; Calculating a ratio of the second resistance value to the first resistance value to obtain a buffer layer ablation risk coefficient, and determining a magnitude relationship between the buffer layer ablation risk coefficient and a preset threshold value to determine whether there is a risk of ablation for the buffer layer of the cable under test; The method of measuring the first resistance value between the buffer layer and the aluminum sheath of the cable to be tested when the operating temperature of the buffer layer reaches the buffer layer starting ablation temperature includes: Determine the resistivity of the buffer layer of the cable under test at different deformation distances; Determine the current density and temperature field of the buffer layer of the cable under test at different interference fit distances and different numbers of poor contact points, and determine the interference fit distance and number of poor contact points when the operating temperature of the buffer layer reaches the initial ablation temperature of the buffer layer based on the determined current density and temperature field of the buffer layer; wherein the interference fit distance is the radial distance that the aluminum sheath of the cable under test is pressed into the buffer layer of the cable under test; and the number of poor contact points is the number of troughs where the aluminum sheath of the cable under test is not in contact with the buffer layer of the cable under test; Determining the first resistance value based on the resistivity of the buffer layer of the cable to be tested at different deformation distances, the interference fit distance when the operating temperature of the buffer layer reaches the initial ablation temperature of the buffer layer, and the number of poor contact points; The determining of the current density and temperature field of the buffer layer of the tested cable under different interference fit distances and different numbers of poor contact points includes: Obtaining the physical parameter values ​​of each layer of the cable to be tested, the physical parameters including at least relative dielectric constant, resistivity, thermal conductivity, constant pressure heat capacity, density and outer diameter parameters; An electrothermal coupling field simulation model of the cable to be tested is established based on the physical parameter values ​​of each layer of the cable to be tested; Obtaining the annual flow rate, ambient temperature, convection heat dissipation coefficient and voltage level parameters of the cable to be tested in order to determine the boundary conditions of the electrothermal coupling field simulation model; Solving the electrothermal coupling field simulation model based on the boundary conditions to obtain the current density and temperature field of the buffer layer under different interference fit distances and different numbers of poor contact points of the tested cable; The determining of the resistivity of the buffer layer of the cable to be tested at different deformation distances includes: Take a buffer layer of preset area and preset thickness as a sample; applying pressure to the sample and recording the deformation distance of the sample; The resistance values ​​of the sample at different deformation distances are measured to obtain the resistivity of the buffer layer of the cable to be tested at different deformation distances.

2. The method for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable according to claim 1, characterized in that: Determine the buffer layer ablation starting temperature of the cable under test, including: Taking the buffer layer of the cable to be tested of a preset length as a test sample, and recording the surface morphology of the test sample before heating; Based on the set temperature gradient, the test piece is heated for a preset time in sequence, and after each heating is completed, the surface morphology of the test piece is compared with the surface morphology of the test piece before heating to determine the starting ablation temperature of the buffer layer of the cable to be tested.

3. The method for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable according to any one of claims 1 to 2, characterized in that: Determining the relationship between the buffer layer ablation risk coefficient and a preset threshold value to determine whether the buffer layer of the cable to be tested has ablation risk includes: When the buffer layer ablation risk coefficient is greater than a preset threshold, it is determined that the buffer layer of the cable under test has ablation risk; otherwise, it is determined that the buffer layer of the cable under test does not have ablation risk.

4. A system for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable, characterized in that: Used to implement the method for evaluating the ablation risk of the buffer layer of a high-voltage corrugated aluminum sheathed cable as claimed in claim 1.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable according to any one of claims 1 to 3 is implemented.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for evaluating the ablation risk of the buffer layer of the high-voltage corrugated aluminum sheathed cable according to any one of claims 1 to 3 is implemented.

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