Method for detecting foreign ions in buffer layer of high-voltage cable and evaluating ablation risk

Abstract

The invention discloses a method for detecting foreign ions in a buffer layer of a high-voltage cable and evaluating ablation risk, and belongs to the field of power cable detection.The method comprises the following steps that the buffer layer of the high-voltage cable is detected based on ion chromatography to obtain the foreign ions; determining risk ion species based on the impurity ions; constructing an ablation risk evaluation model based on the risk ion species; and obtaining an evaluation grade of the buffer layer to be evaluated based on the evaluation model of the ablation risk. The method can effectively control the product quality of the buffer layer of the high-voltage cable, prevents the ablation fault of the high-voltage cable, and is of great significance to the improvement of the manufacturing level of the high-voltage cable and the improvement of the operation reliability of a power system.

Description

Technical Field

[0001] This invention belongs to the field of power cable testing technology, and in particular relates to a method for detecting impurity ions and assessing ablation risk in the buffer layer of high-voltage cables. Background Technology

[0002] High-voltage cables are a critical component in power transmission, and high-voltage cable ablation failures pose a significant safety challenge. Past research on ablation failures has shown that electrochemical corrosion caused by moisture absorption of sodium polyacrylate water-blocking powder in the buffer layer is the root cause of the failure. However, impurity ions in the buffer layer are a crucial and unavoidable influencing factor. For example, halogen anions can cause pitting corrosion on the aluminum sheet surface, and the competitive adsorption of anions can significantly accelerate the electrochemical corrosion of the aluminum sheath, leading to the high-voltage cable being decommissioned after a short period of service due to ablation. Currently, there is a lack of methods for controlling the ionic composition of high-voltage cable buffer layers and quality evaluation standards, severely hindering the improvement of high-voltage cable manufacturing standards and operational safety. Therefore, this invention proposes a method for detecting impurity ions and assessing ablation risk in high-voltage cable buffer layers. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a method for detecting impurity ions and assessing ablation risk in the buffer layer of high-voltage cables, thereby resolving the issues present in the prior art.

[0004] To achieve the above objectives, this invention provides a method for detecting impurity ions and assessing ablation risk in the buffer layer of a high-voltage cable, comprising:

[0005] Impurity ions were detected in the buffer layer of high-voltage cables using ion chromatography.

[0006] The types of risk ions are determined based on the impurity ions;

[0007] Ablation risk assessment model is constructed based on the types of risk ions described.

[0008] The evaluation level of the buffer layer to be evaluated is obtained based on the ablation risk evaluation model.

[0009] Optionally, the process of obtaining impurity ions includes:

[0010] Ionic components were extracted from the buffer layer sample to obtain the impregnation solution after volume adjustment;

[0011] Ion chromatography was used to analyze the impregnation solution after volume adjustment to obtain the ion species and quantitative detection results;

[0012] Impurity ions are determined based on the types of ions and the quantitative detection results.

[0013] Optionally, the quantitative detection results include: the ion content of the high-voltage cable buffer layer;

[0014] The formula for calculating the ion content of the high-voltage cable buffer layer is as follows:

[0015]

[0016] In the formula, Q i denoted by , x represents the content of the i-th ion in the high-voltage cable buffer layer, n represents the amount of impregnation solution after the buffer layer sample is brought to a constant volume, and m represents the mass of the buffer layer sample.

[0017] Optionally, the types of risk ions include: F - Cl - NO3 - SO4 2- Wherein, the risk ions are the ion content of the high-voltage cable buffer layer.

[0018] Optionally, the process of constructing an ablation risk assessment model based on the types of risk ions includes:

[0019] The factor set is determined based on the ion content of the high-voltage cable buffer layer;

[0020] Determine the evaluation set and weight set;

[0021] The evaluation matrix is ​​determined based on the membership degree of the factors in the factor set to the evaluation levels in the evaluation set.

[0022] Based on the evaluation matrix, the fuzzy vectors on the factor set are transformed into fuzzy vectors on the evaluation set to obtain the ablation risk assessment model.

[0023] Optionally, the expression for transforming the fuzzy vector on the factor set into a fuzzy vector on the evaluation set is:

[0024] B = A·G

[0025] In the formula, B represents a fuzzy vector on the evaluation set, A represents a fuzzy vector on the factor set, and G represents the evaluation matrix.

[0026] Optionally, the evaluation level of the buffer layer to be evaluated is evaluated based on the maximum membership principle according to the ablation risk assessment model.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] This invention provides a method for detecting impurity ions and assessing ablation risk in the buffer layer of high-voltage cables, effectively improving the efficiency and accuracy of cable safety performance evaluation. Using ion chromatography, this method can accurately detect impurity ions in the buffer layer of high-voltage cables, thereby identifying the types of risk ions that may cause ablation. By constructing an ablation risk assessment model, this method can quantitatively assess the ablation risk of the cable buffer layer and provide a specific evaluation level. This process not only improves the accuracy of cable fault prediction but also helps optimize cable maintenance and replacement strategies, reducing economic losses and safety risks caused by cable faults, which is of great significance for the long-term stable operation of high-voltage cables. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0030] Figure 1 The risk ion components in the ablation buffer layer obtained by the ion chromatography method used in this embodiment of the invention;

[0031] Figure 2 This is a schematic diagram of a method for detecting impurity ions and assessing ablation risk in a high-voltage cable buffer layer according to an embodiment of the present invention. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0034] Example 1

[0035] Ion chromatography is a rapid and accurate method for detecting ionic components and concentrations. Using ion chromatography in the manufacturing process of buffer layers and high-voltage cables allows for the detection of ionic components in the buffer layer, controlling impurity ions and effectively controlling the product quality of high-voltage cable buffer layers. This prevents high-voltage cable burn-out failures and is of great significance for improving the manufacturing level of high-voltage cables and enhancing the reliability of power system operation.

[0036] This invention utilizes chromatographic testing to detect impurity ions in the buffer layer and selects impurity ions that pose a risk of ablation in the buffer layer as evaluation indicators of the buffer layer quality. This can effectively improve the quality of the buffer layer and prevent high-voltage cable ablation failures.

[0037] This invention proposes a method for detecting impurity ions in the buffer layer of high-voltage cables using ion chromatography. It identifies the ablation-risk ions present in the buffer layer and establishes an evaluation model using the content of these risk ions as an evaluation factor to assess the ablation risk of the high-voltage cable buffer layer after moisture absorption. The method evaluates the impact of ions in the buffer layer on its ablation, providing a more comprehensive assessment of the buffer layer's quality. This technical solution is beneficial for further improving the manufacturing level of buffer layers and mitigating the ablation problem in high-voltage cables.

[0038] like Figure 1 As shown in the figure, this embodiment provides a method for detecting impurity ions and assessing ablation risk in a high-voltage cable buffer layer, including the following steps: detecting impurity ions in the high-voltage cable buffer layer based on ion chromatography; determining the types of risk ions based on the impurity ions; constructing an ablation risk assessment model based on the types of risk ions; and obtaining the assessment level of the buffer layer to be evaluated based on the ablation risk assessment model.

[0039] As a specific implementation of this embodiment, in a first aspect, the present invention provides a method for detecting impurity ions in a high-voltage cable buffer layer, which includes the following steps: extracting ionic components from a buffer layer sample to obtain a fixed-volume impregnation solution; analyzing the fixed-volume impregnation solution using ion chromatography to obtain ion types and quantitative detection results; and determining impurity ions based on ion types and quantitative detection results.

[0040] Step S01, Selection of buffer layer sample: Select a flat and uniform buffer layer that is undamaged after drying, cut it into block samples, and proceed to step S02.

[0041] Step S02, Extraction of ionic components in buffer layer: Weigh mg of buffer layer sample into conical flask, add n ml of deionized water, soak at 25℃ for 24 h to obtain impregnation solution, filter the impregnation solution with a 0.22 μm filter membrane and then make up to n ml with deionized water, proceed to step S03;

[0042] Step S03, Ion Chromatography Test: Obtain ion chromatograms, and based on the retention time, area, and standard curve of the ion chromatographic peaks obtained from the ion chromatography detection, obtain the ion types and quantitative detection results.

[0043] Furthermore, in step S03, ion chromatography was performed using a Metrosep A Supp 5-250 / 4.0 column to analyze the anionic components in the impregnation solution. The column temperature was 40℃ and the flow rate was 0.7 ml / min.

[0044] Furthermore, if step S03 measures the content of a certain ion to be x ppm, then the content of that ion in the buffer layer is Q. i :

[0045]

[0046] Secondly, the present invention provides a method for assessing the risk of ablation of a high-voltage cable buffer layer after moisture absorption, taking into account impurity ion indicators, including:

[0047] Step S11: Determine the types of risk ions in the buffer layer that can trigger or promote cable ablation.

[0048] Step S12, the risk ion content Q i As evaluation factors, an evaluation model for assessing the risk of ablation of the buffer layer of high-voltage cables after moisture absorption is constructed based on these factors. This includes: determining a factor set based on the ion content of the high-voltage cable buffer layer; determining the evaluation set and weight set; calculating the evaluation matrix based on the membership degrees of factors in the factor set to evaluation levels in the evaluation set; and transforming the fuzzy vectors on the factor set into fuzzy vectors on the evaluation set based on the evaluation matrix to obtain the ablation risk assessment model.

[0049] Step S13: Obtain the evaluation level of the buffer layer to be evaluated through the model.

[0050] Furthermore, the types of hazardous ions should include, but are not limited to: F - Cl - NO3 - SO4 2- .

[0051] Furthermore, the risk ion content Q i The impurity ions in the high-voltage cable buffer layer were detected by the method provided by this invention.

[0052] Furthermore, an evaluation model for assessing the risk of ablation of the high-voltage cable buffer layer after moisture absorption, constructed based on the aforementioned evaluation factors, should include:

[0053] Step S121, determine the factor set U = {u1, u2, ..., u} n};

[0054] Step S122, determine the evaluation set V = {v1, v2, ..., v} n};

[0055] Step S123, determine the weight set A = {a1, a2, ..., a...} m};

[0056] Where n is the number of risk ions and m is the number of evaluation levels;

[0057] In the evaluation model for the risk of ablation of the buffer layer of a high-voltage cable after it becomes damp, the factor in factor set U is the risk ion content Q. i Determine the evaluation set V = {low risk, medium risk, high risk}.

[0058] Step S124, determine the evaluation matrix:

[0059] The membership function of factor u to evaluation level v is:

[0060] Smaller in size:

[0061]

[0062] Intermediate type:

[0063]

[0064] Larger size:

[0065]

[0066] Where x is the measured value of the evaluation factor;

[0067] a, b, and c are thresholds that characterize the degree of risk.

[0068] Evaluation Matrix g ij It represents the membership degree of the evaluation object x to the j-th evaluation level on the i-th evaluation factor.

[0069] Step S125, establish a comprehensive evaluation model:

[0070] The fuzzy vector on U is transformed into a fuzzy vector B = A·G on V through fuzzy transformation.

[0071] Step S126: Using the maximum membership principle, evaluate the risk of ablation of the buffer layer after it becomes damp.

[0072] This invention takes into account impurity ions in the buffer layer, which have not been previously considered. Impurity ions are a key factor affecting the quality of the buffer layer. The proposed method for detecting impurity ions in the buffer layer of high-voltage cables uses ion chromatography, which can accurately, effectively and conveniently test the content of impurity ions in the buffer layer.

[0073] This invention identifies ablation-risk ions present in the buffer layer and establishes an evaluation model using the content of these risk ions as an evaluation factor to assess the ablation risk of high-voltage cable buffer layers after moisture absorption. The model evaluates the impact of ions in the buffer layer on ablation and provides a more comprehensive assessment of the buffer layer's quality. This technical solution is beneficial for further improving the manufacturing level of buffer layers and mitigating the ablation problem in high-voltage cables.

[0074] Example 2

[0075] This embodiment provides the risk ions in the ablation buffer layer obtained by the ion chromatography method used in the invention. Specifically, F appears at a retention time of 6.82 min. - Ions, concentration 2.55 ppm; Cl appeared at 8.81 min. - The concentration of the ion was 1.67 ppm; NO3 appeared at 13.97 min. - The ion concentration was 2.11 ppm; SO4 appeared at 24.46 min. 2- Ions, concentration 6.54 ppm.

[0076] During testing, the buffer layer sample weighed 5g and was diluted to 100ml with deionized water. According to the formula in this invention, the ion content in the buffer layer is shown in Table 1 and... Figure 1 As shown:

[0077] Table 1

[0078]

[0079]

[0080] like Figure 2 As shown, this embodiment is to further illustrate the method for assessing the risk of ablation of a high-voltage cable buffer layer after moisture absorption, taking into account impurity ion indicators. An ablation risk assessment is performed on the buffer layer described in this embodiment.

[0081] Factor set U = {0.0051%, 0.0033%, 0.0042%, 0.0131%};

[0082] Evaluation set V = {low risk, medium risk, high risk};

[0083] The weight set A = {0.4, 0.4, 0.1, 0.1};

[0084] The risk thresholds for ion content are shown in Table 2:

[0085] Table 2

[0086]

[0087] Constructing the evaluation matrix:

[0088]

[0089] The fuzzy vector on U is transformed into a fuzzy vector on V by fuzzy transformation, which is B = A·G = {0.1, 0, 0.9}. Based on the maximum membership degree, the buffer layer is identified as high-risk.

[0090] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for detecting impurity ions and assessing ablation risk in a high-voltage cable buffer layer, characterized in that: The following steps are involved: The impurity ions are obtained by detecting the buffer layer of the high-voltage cable based on ion chromatography; determining risk ion types based on the impurity ions; Constructing an ablation risk assessment model based on the risk ion species; An evaluation grade of the buffer layer to be evaluated is obtained based on the evaluation model of the ablation risk.

2. The method according to claim 1, characterized in that The process of obtaining impurity ions includes: Extracting ion components in the buffer layer sample to obtain a fixed volume impregnation solution; The ion chromatography is used to analyze the immersion solution after the volume is fixed to obtain the ion types and quantitative detection results; The impurity ions are determined based on the ion species and the quantitative detection results.

3. The method according to claim 2, characterized in that The quantitative test results include: ion content of the high-voltage cable buffer layer; Among them, the calculation expression of the ion content of the high-voltage cable buffer layer is: In the formula, Q i It represents the content of the i-th ion in the buffer layer of the high-voltage cable, x represents the content of the i-th ion in the buffer layer sample, n represents the amount of the impregnation liquid after the buffer layer sample is fixed in volume, and m represents the mass of the buffer layer sample.

4. The method according to claim 3, characterized in that The risk ion types include: F - , Cl - , NO3 - , SO4 2- ; Among them, the risk ions are the ion content of the high-voltage cable buffer layer.

5. The method according to claim 4, characterized in that The process of constructing an ablation risk assessment model based on the risk ion species includes: Determining a factor set based on the ion content of the high voltage cable buffer layer; Determine the evaluation set and weight set; Determine an evaluation matrix based on the membership calculation of the factor set factors to the evaluation levels in the evaluation set; Based on the evaluation matrix, the fuzzy vector on the factor set is transformed into a fuzzy vector on the evaluation set to obtain an ablation risk evaluation model.

6. The method according to claim 5, characterized in that The expression for transforming the fuzzy vector on the factor set into the fuzzy vector on the evaluation set is: B=A·G In the formula, B represents the fuzzy vector on the evaluation set, A represents the fuzzy vector on the factor set, and G represents the evaluation matrix.

7. The method according to claim 6, characterized in that Based on the ablation risk assessment model, the maximum membership principle is adopted to evaluate the evaluation level of the buffer layer to be evaluated.

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