Alternative cable selection method

Abstract

The invention provides a replacement cable selection method, and relates to the technical field of cable replacement, and the method comprises the steps: calculating the conductor shielding field intensity of a to-be-replaced cable and the insulation shielding field intensity of the to-be-replaced cable; performing preliminary screening from existing selectable cables to obtain a sample cable set; obtaining all types of performance evaluation values of each sample cable in each monitoring period; constructing a performance comprehensive evaluation matrix corresponding to each monitoring period of each sample cable; a comprehensive performance evaluation value of each sample cable is calculated, and a replacement cable is selected based on the comprehensive performance evaluation value of each sample cable. The replacement cable is selected through systematic steps, the scientificity of the selection process of the replacement cable is ensured, the electrical performance parameters of the to-be-replaced cable are fully considered, the influence of the actual parameters and limiting conditions of the construction environment on the replacement cable is emphasized, the possibility of cable failure is reduced, and the construction efficiency is improved. And the total cost of laying and later maintenance is fully considered in the cable selection process, so that the operation cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of cable replacement, and in particular relates to a method for selecting a replacement cable. Background Art

[0002] Cables are key components of modern social infrastructure and energy transmission. With the continuous advancement of technology and the development of society, cable systems are facing the need for continuous updating and replacement. Traditional cable replacement methods often lack systematic steps, resulting in reliance on experience or a single standard when selecting replacement cables, which can easily cause the cable performance to not match the actual application environment, thereby affecting the use and safety of the cables. At the same time, existing methods may not fully consider the electrical performance parameters such as the conductor and insulation shielding field strength of the cable to be replaced, so that the selected cable may not meet specific electrical performance requirements, increasing the risk of failure. When selecting replacement cables, existing technologies may not pay enough attention to the actual parameters and restrictions of the construction environment, resulting in the selected cables not having good applicability in specific environments, increasing the possibility of cable failure. In the process of cable selection, existing technologies may not fully consider the total cost of laying and subsequent maintenance, which can easily lead to the final selected cables not having economic advantages and increasing operating costs. Summary of the invention

[0003] The present invention provides a replacement cable selection method to solve at least one of the above-mentioned technical problems.

[0004] In order to solve the above technical problems, the present invention discloses a method for selecting a replacement cable, comprising the following steps:

[0005] S1. Obtaining rated parameters of the cable to be replaced, and calculating the conductor shielding field strength of the cable to be replaced and the insulation shielding field strength of the cable to be replaced based on the rated parameters of the cable to be replaced;

[0006] S2. Collect environmental parameters of the construction environment and determine the limiting conditions of the current construction environment based on the collected results;

[0007] S3. Based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced, the insulation shielding field strength of the cable to be replaced and the restrictive conditions under the current construction environment, a preliminary screening is performed from the existing optional cables to obtain a sample cable set;

[0008] S4. Perform a performance test on the sample cables, collect the physical parameters of each sample cable in each monitoring cycle during the test, and obtain all types of performance evaluation values ​​of each sample cable in each monitoring cycle based on the physical parameters of each sample cable in each monitoring cycle during the test;

[0009] S5. Based on the physical parameters of each sample cable in each monitoring cycle during the test and all types of performance evaluation values ​​of each monitoring cycle, a comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable is constructed;

[0010] S6. Based on the comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable, calculate the comprehensive performance evaluation value of each sample cable, and select a replacement cable based on the comprehensive performance evaluation value of each sample cable.

[0011] Preferably, obtaining the rated parameters of the cable to be replaced, and calculating the conductor shielding field strength of the cable to be replaced and the insulation shielding field strength of the cable to be replaced based on the rated parameters of the cable to be replaced, comprises:

[0012] Conductor shielding field strength of the cable to be replaced:

[0013]

[0014] Insulation shielding field strength of the cable to be replaced:

[0015] Among them, E max is the conductor shielding field strength of the cable to be replaced, E min is the insulation shielding field strength of the cable to be replaced, U0 is the rated voltage of the cable to be replaced, D is the insulation outer radius of the cable to be replaced, d is the insulation inner radius of the cable to be replaced, and Ln is the logarithm with base e.

[0016] Preferably, collecting environmental parameters of the construction environment and judging the limiting conditions in the current construction environment based on the collected results include:

[0017] S21. Collect the temperature and humidity of the construction environment, the pH value of the cable contact environment, and the external forces on the cables;

[0018] S22, judging the restrictive conditions in the current construction environment based on the collected temperature, humidity, pH value of the cable contact environment, external force on the cable and preset reference ambient temperature, preset reference ambient humidity, preset reference cable contact environment pH value, and preset reference cable external force;

[0019] S23. Based on the constraints in the current construction environment, an upper limit value of the constraints is given.

[0020] Preferably, step S22 includes:

[0021] Compare the difference between the temperature of the construction environment and the preset reference environment temperature, the difference between the humidity of the construction environment and the preset reference environment humidity, the difference between the pH value of the cable contact environment in the construction environment and the preset reference cable contact environment pH value, and the difference between the external force of the cable in the construction environment and the preset reference cable;

[0022] If the difference between the temperature of the construction environment and the preset reference ambient temperature is greater than the preset temperature difference, the temperature adaptability of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the temperature adaptability range of the cable.

[0023] If the difference between the construction environment humidity and the preset reference environment humidity is greater than the preset humidity difference, the waterproof performance of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the waterproof performance range of the cable.

[0024] If the difference between the pH value of the cable contact environment in the construction environment and the preset reference cable contact environment pH value is greater than the preset pH value difference, the corrosion resistance of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the corrosion resistance range of the cable.

[0025] If the difference between the external force applied to the cable in the construction environment and the external force applied to the preset reference cable is greater than the preset external force difference, the mechanical strength performance of the cable will be used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the mechanical strength range of the cable.

[0026] Preferably, based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced, the insulation shielding field strength of the cable to be replaced and the constraints in the current construction environment, a preliminary screening is performed from the existing optional cables to obtain a sample cable set, including:

[0027] S31. Select a cable with the same rated parameters as the cable to be replaced from the available optional cables as a preliminary screening cable;

[0028] S32, selecting cables whose conductor shielding field strength and insulation shielding field strength are both higher than those of the cables to be replaced from the cables in the primary preliminary screening, as cables for the secondary preliminary screening;

[0029] S33. Screen out cables that meet the upper limit value of the restriction condition from the secondary preliminary screening cables as a sample cable set.

[0030] Preferably, step S4 comprises:

[0031] S41, laying each sample cable in a simulated construction environment arranged in advance in the same way as the replacement cable, and simulating the transmission signal of the cable to be replaced during actual working, and connecting each sample cable to an energy spectrum analyzer, a moisture tester, and an insulation resistance tester;

[0032] The environmental parameters of the simulated construction environment are the same as the laying environmental parameters of the cable to be replaced;

[0033] S42. Collect the percentage of copper oxygen content of each sample cable in each monitoring cycle during the test by using an energy spectrum analyzer;

[0034] The moisture content of each cable connector end of each sample during each monitoring cycle during the test is collected by a moisture tester;

[0035] The insulation resistance change of each sample cable in each monitoring cycle during the test is collected by an insulation resistance tester;

[0036] S43. Input the percentage of copper oxygen content of each sample cable in each monitoring cycle during the test, the moisture content of each sample cable connector in each monitoring cycle during the test, and the change in insulation resistance of each sample cable in each monitoring cycle during the test into the trained cable antioxidant performance evaluation model, cable waterproof performance evaluation model, and cable aging performance evaluation model, respectively, to obtain the cable antioxidant performance evaluation value, cable waterproof performance evaluation value, and cable aging performance evaluation value of each sample cable in each monitoring cycle.

[0037] Preferably, based on the physical parameters of each sample cable in each monitoring cycle during the test and all types of performance evaluation values ​​of each monitoring cycle, a comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable is constructed:

[0038] in, is the comprehensive performance evaluation matrix corresponding to the i-th sample cable, a i1 is the percentage of copper oxygen content in the first monitoring cycle of the i-th sample cable, a i2 is the percentage of copper oxygen content in the second monitoring cycle of the i-th sample cable, a in is the percentage of copper oxygen content in the i-th sample cable in the n-th monitoring cycle, b i1 is the moisture content at the cable joint of the ith sample cable in the first monitoring cycle, b i2 is the moisture content at the cable joint of the ith sample cable in the second monitoring cycle, b in is the moisture content at the cable joint end of the i-th sample cable in the n-th monitoring cycle, c i1 is the insulation resistance change of the ith sample cable in the first monitoring cycle, c i2 is the insulation resistance change of the ith sample cable in the second monitoring cycle, c in is the insulation resistance change of the i-th sample cable in the n-th monitoring cycle, A i1 is the cable antioxidant performance evaluation value of the ith sample cable in the first monitoring cycle, A i2 is the cable antioxidant performance evaluation value of the ith sample cable in the second monitoring cycle, A in is the cable antioxidant performance evaluation value of the i-th sample cable in the n-th monitoring cycle, B i1is the cable waterproof performance evaluation value of the ith sample cable in the first monitoring cycle, B i2 is the cable waterproof performance evaluation value of the ith sample cable in the second monitoring cycle, B in is the cable waterproof performance evaluation value of the i-th sample cable in the n-th monitoring cycle, C i1 is the cable aging performance evaluation value of the first monitoring cycle of the i-th sample cable, C i2 is the cable aging performance evaluation value of the second monitoring cycle of the i-th sample cable, C in It is the cable aging performance evaluation value of the i-th sample cable in the n-th monitoring cycle.

[0039] Preferably, based on the comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable, a comprehensive performance evaluation value of each sample cable is calculated, and a replacement cable is selected based on the comprehensive performance evaluation value of each sample cable, including:

[0040] S61. Based on the comprehensive performance evaluation matrix corresponding to each monitoring period of each sample cable, obtain the main influencing value and the secondary influencing value of the comprehensive performance evaluation value of each sample cable;

[0041] S62, calculating the comprehensive performance evaluation value of each sample cable based on the main influencing value of the comprehensive performance evaluation value of each sample cable and the secondary influencing value of the comprehensive performance evaluation value;

[0042] S63, comparing the comprehensive performance evaluation value of each sample cable, selecting the sample cables with the top two comprehensive performance evaluation values, comparing the total cost of laying and subsequent maintenance of the two sample cables, and if the difference between the total cost of laying and subsequent maintenance of the two sample cables is less than the preset cost difference, selecting the sample cable with the top one as the replacement cable;

[0043] Otherwise, the second-ranked sample cable is selected as the replacement cable.

[0044] Preferably, step S61 includes:

[0045] Delete each type of performance evaluation value and its corresponding monitoring data from the performance comprehensive evaluation matrix element corresponding to each monitoring cycle of each sample cable to obtain an evaluation matrix for each type of performance;

[0046] If the rank of the evaluation matrix of each type of performance of the sample cable is greater than the preset threshold of the corresponding type of performance evaluation value, then the performance evaluation value of the corresponding type in the last cycle of the sample cable is used as the main influencing value of the comprehensive performance evaluation value; otherwise, it is used as the secondary influencing value of the comprehensive performance evaluation value.

[0047] Preferably, the comprehensive performance evaluation value of each sample cable is calculated based on the main influencing value of the comprehensive performance evaluation value of each sample cable and the secondary influencing value of the comprehensive performance evaluation value:

[0048] in, is the comprehensive performance evaluation value of the i-th sample cable, u is the total number of main influencing values ​​of the comprehensive performance evaluation value of the i-th sample cable, X j is the jth main influencing value of the comprehensive performance evaluation value of the i-th sample cable, e is a natural number, and its value is 2.71, Y k It is the secondary influence value of the kth comprehensive performance evaluation value of the comprehensive performance evaluation value of the ith sample cable.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention provides a systematic procedure for selecting a replacement cable, avoiding the situation of relying on experience or a single standard. Through clear steps, it ensures that the selection process of the replacement cable is scientific and accurate, so as to improve the use effect and safety of the cable, and fully considers the electrical performance parameters of the cable to be replaced, such as the conductor and insulation shielding field strength, to ensure that the selected cable can meet the specific electrical performance requirements. In this way, the risk of failure can be reduced, the reliability of the cable system can be guaranteed, attention can be paid to the influence of the actual parameters and restrictions of the construction environment on the replacement cable, and the selected cable can be ensured to have good applicability in a specific environment, reduce the possibility of cable failure, improve the reliability of the system, and fully consider the total cost of laying and subsequent maintenance in the cable selection process. By comprehensively considering the economic efficiency, a replacement cable with a lower economic cost is selected, thereby reducing the operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0052] Figure 1 A flow chart of a replacement cable selection method proposed for the present invention. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0054] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0055] The present invention provides the following embodiments

[0056] Example 1

[0057] The embodiment of the present invention provides a method for selecting a replacement cable. Figure 1 As shown, the following steps are included:

[0058] S1. Obtaining rated parameters of the cable to be replaced, and calculating the conductor shielding field strength of the cable to be replaced and the insulation shielding field strength of the cable to be replaced based on the rated parameters of the cable to be replaced;

[0059] S2. Collect environmental parameters of the construction environment and determine the limiting conditions of the current construction environment based on the collected results;

[0060] S3. Based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced, the insulation shielding field strength of the cable to be replaced and the restrictive conditions under the current construction environment, a preliminary screening is performed from the existing optional cables to obtain a sample cable set;

[0061] S4. Perform a performance test on the sample cables, collect the physical parameters of each sample cable in each monitoring cycle during the test, and obtain all types of performance evaluation values ​​of each sample cable in each monitoring cycle based on the physical parameters of each sample cable in each monitoring cycle during the test;

[0062] S5. Based on the physical parameters of each sample cable in each monitoring cycle during the test and all types of performance evaluation values ​​of each monitoring cycle, a comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable is constructed;

[0063] S6. Based on the comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable, calculate the comprehensive performance evaluation value of each sample cable, and select a replacement cable based on the comprehensive performance evaluation value of each sample cable.

[0064] In this embodiment, the rated parameters of the cable to be replaced include rated voltage, insulation inner radius and insulation outer radius.

[0065] In this embodiment, the environmental parameters of the construction environment include the temperature and humidity of the construction environment, the pH value of the cable contact environment, and the external force exerted on the cable.

[0066] The working principle and beneficial effects of the above technical solution are as follows: the present invention can effectively improve the accuracy and reliability of cable replacement through systematic steps. During the implementation process, the rated parameters of the cable to be replaced are first obtained, and the conductor and insulation shielding field strengths are calculated to ensure that the newly selected cable can meet the corresponding electrical performance requirements. Subsequently, the environmental parameters of the construction environment are collected and the restriction conditions are evaluated to ensure the applicability of the selected cable in a specific environment. On this basis, combined with the preliminary screening of existing optional cables, a sample cable collection is formed, and performance tests are performed on the sample cables to obtain physical parameters and performance evaluation values. By constructing a comprehensive performance evaluation matrix, the comprehensive performance evaluation value of each sample cable is quantified, and a replacement cable with superior performance is selected, thereby achieving the purpose of optimizing cable selection, improving construction safety and reducing subsequent maintenance costs;

[0067] The present invention provides a systematic procedure for selecting a replacement cable, avoiding the situation of relying on experience or a single standard. Through clear steps, it ensures that the selection process of the replacement cable is scientific and accurate, so as to improve the use effect and safety of the cable, and fully considers the electrical performance parameters of the cable to be replaced, such as the conductor and insulation shielding field strength, to ensure that the selected cable can meet the specific electrical performance requirements. In this way, the risk of failure can be reduced, the reliability of the cable system can be guaranteed, attention can be paid to the influence of the actual parameters and restrictions of the construction environment on the replacement cable, and the selected cable can be ensured to have good applicability in a specific environment, reduce the possibility of cable failure, improve the reliability of the system, and fully consider the total cost of laying and subsequent maintenance in the cable selection process. By comprehensively considering the economic efficiency, a replacement cable with a lower economic cost is selected, thereby reducing the operating cost.

[0068] Example 2

[0069] On the basis of Embodiment 1, the rated parameters of the cable to be replaced are obtained, and the conductor shielding field strength of the cable to be replaced and the insulation shielding field strength of the cable to be replaced are calculated based on the rated parameters of the cable to be replaced, including:

[0070] Conductor shielding field strength of the cable to be replaced:

[0071]

[0072] Insulation shielding field strength of the cable to be replaced:

[0073] Among them, E maxis the conductor shielding field strength of the cable to be replaced, E min is the insulation shielding field strength of the cable to be replaced, U0 is the rated voltage of the cable to be replaced, D is the insulation outer radius of the cable to be replaced, d is the insulation inner radius of the cable to be replaced, and Ln is the logarithm with base e.

[0074] The working principle and beneficial effects of the above technical solution are as follows: the conductor shielding field strength and insulation shielding field strength obtained by calculation can be used as one of the bases for selecting replacement cables. Such a calculation method can more accurately evaluate the electrical performance of the cable to be replaced, thereby guiding the selection of more suitable replacement cables and improving the reliability and safety of the cable system.

[0075] Example 3

[0076] On the basis of Example 1, environmental parameters of the construction environment are collected, and based on the collected results, the limiting conditions in the current construction environment are determined, including:

[0077] S21. Collect the temperature and humidity of the construction environment, the pH value of the cable contact environment, and the external forces on the cables;

[0078] S22, judging the restrictive conditions in the current construction environment based on the collected temperature, humidity, pH value of the cable contact environment, external force on the cable and preset reference ambient temperature, preset reference ambient humidity, preset reference cable contact environment pH value, and preset reference cable external force;

[0079] S23. Based on the constraints in the current construction environment, an upper limit value of the constraints is given.

[0080] The working principle and beneficial effects of the above technical solution are as follows: by collecting and judging the parameters of the construction environment and giving the corresponding upper limit values ​​of the restriction conditions, the applicability and reliability of the cable to be replaced can be evaluated more accurately.

[0081] Example 4

[0082] Based on Example 3, step S22 includes:

[0083] Compare the difference between the temperature of the construction environment and the preset reference environment temperature, the difference between the humidity of the construction environment and the preset reference environment humidity, the difference between the pH value of the cable contact environment in the construction environment and the preset reference cable contact environment pH value, and the difference between the external force of the cable in the construction environment and the preset reference cable;

[0084] If the difference between the temperature of the construction environment and the preset reference ambient temperature is greater than the preset temperature difference, the temperature adaptability of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the temperature adaptability range of the cable.

[0085] If the difference between the construction environment humidity and the preset reference environment humidity is greater than the preset humidity difference, the waterproof performance of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the waterproof performance range of the cable.

[0086] If the difference between the pH value of the cable contact environment in the construction environment and the preset reference cable contact environment pH value is greater than the preset pH value difference, the corrosion resistance of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the corrosion resistance range of the cable.

[0087] If the difference between the external force applied to the cable in the construction environment and the external force applied to the preset reference cable is greater than the preset external force difference, the mechanical strength performance of the cable will be used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the mechanical strength range of the cable.

[0088] The working principle and beneficial effects of the above technical solution: By comparing the temperature, humidity, pH value of the cable contact environment and the difference between the external force of the cable and the preset reference environment, the influence of various environmental factors on the cable performance is systematically evaluated;

[0089] In step S22, if the difference between the temperature of the construction environment and the preset reference temperature exceeds the preset temperature difference, the temperature adaptability of the cable is included in the restriction condition, and the upper limit value of the restriction condition is set to the temperature adaptability range of the cable; if the difference between the humidity of the construction environment and the reference humidity exceeds the preset humidity difference, the waterproof performance of the cable becomes a restriction condition, and the upper limit value is the waterproof performance range of the cable; similarly, if the difference in pH of the environment in which the cable contacts exceeds the preset pH difference, the corrosion resistance of the cable is regarded as a restriction condition, and the upper limit value is set to its corrosion resistance range; finally, if the difference in the external force of the environment applied to the cable exceeds the preset external force difference, the mechanical strength performance of the cable is used as one of the restriction conditions, and its upper limit value is the mechanical strength range of the cable.

[0090] Through this detailed judgment and evaluation method, the impact of the construction environment on cable performance can be determined more comprehensively and accurately, thereby providing a more reliable basis for the selection of replacement cables, ensuring the applicability and safety of the newly selected cables in specific construction environments, and significantly improving the overall reliability and service life of the cable system.

[0091] Example 5

[0092] On the basis of Example 1, based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced, the insulation shielding field strength of the cable to be replaced and the constraints under the current construction environment, a preliminary screening is performed from the existing optional cables to obtain a sample cable set, including:

[0093] S31. Select a cable with the same rated parameters as the cable to be replaced from the available optional cables as a preliminary screening cable;

[0094] S32, selecting cables whose conductor shielding field strength and insulation shielding field strength are both higher than those of the cables to be replaced from the cables in the primary preliminary screening, as cables for the secondary preliminary screening;

[0095] S33. Screen out cables that meet the upper limit value of the restriction condition from the secondary preliminary screening cables as a sample cable set.

[0096] The working principle and beneficial effects of the above technical solution are as follows: cables with the same rated parameters as the cables to be replaced are screened out from the existing optional cables as the primary screening cables. This step ensures that the primary selected cables match the cables to be replaced in terms of electrical specifications, laying the foundation for subsequent screening. On the basis of the primary screening, cables with higher conductor shielding field strength and higher insulation shielding field strength than the cables to be replaced are further screened out as the secondary preliminary screening cables. This process ensures that the selected cables have a higher safety margin in shielding performance and can better adapt to possible electromagnetic interference. Cables that meet the upper limit value of the restriction conditions under the construction environment are selected from the secondary preliminary screening cables to form a final sample cable collection. By comprehensively considering the performance of the cables and the requirements of the construction environment, the selected sample cable collection will be more applicable and reliable.

[0097] Example 6

[0098] Based on Example 1, step S4 includes:

[0099] S41, laying each sample cable in a simulated construction environment arranged in advance in the same way as the replacement cable, and simulating the transmission signal of the cable to be replaced during actual working, and connecting each sample cable to an energy spectrum analyzer, a moisture tester, and an insulation resistance tester;

[0100] The environmental parameters of the simulated construction environment are the same as the laying environmental parameters of the cable to be replaced;

[0101] S42. Collect the percentage of copper oxygen content of each sample cable in each monitoring cycle during the test by using an energy spectrum analyzer;

[0102] The moisture content of each cable connector end of each sample during each monitoring cycle during the test is collected by a moisture tester;

[0103] The insulation resistance change of each sample cable in each monitoring cycle during the test is collected by an insulation resistance tester;

[0104] S43. Input the percentage of copper oxygen content of each sample cable in each monitoring cycle during the test, the moisture content of each sample cable connector in each monitoring cycle during the test, and the change in insulation resistance of each sample cable in each monitoring cycle during the test into the trained cable antioxidant performance evaluation model, cable waterproof performance evaluation model, and cable aging performance evaluation model, respectively, to obtain the cable antioxidant performance evaluation value, cable waterproof performance evaluation value, and cable aging performance evaluation value of each sample cable in each monitoring cycle.

[0105] The working principle and beneficial effects of the above technical solution are: to evaluate in detail the performance indicators such as copper oxygen content, moisture content and insulation resistance of each sample cable during the test, so as to accurately evaluate the cable's anti-oxidation performance, waterproof performance and aging performance. These evaluation values ​​will provide an important reference for the final cable selection to ensure that the selected cable can maintain stable and reliable performance in long-term use.

[0106] Example 7

[0107] On the basis of Example 6, based on the physical parameters of each sample cable in each monitoring cycle during the test and all types of performance evaluation values ​​of each monitoring cycle, a comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable is constructed:

[0108] in, is the comprehensive performance evaluation matrix corresponding to the i-th sample cable, a i1 is the percentage of copper oxygen content in the first monitoring cycle of the i-th sample cable, a i2 is the percentage of copper oxygen content in the second monitoring cycle of the i-th sample cable, a in is the percentage of copper oxygen content in the i-th sample cable in the n-th monitoring cycle, b i1 is the moisture content at the cable joint of the ith sample cable in the first monitoring cycle, b i2 is the moisture content at the cable joint of the ith sample cable in the second monitoring cycle, b in is the moisture content at the cable joint end of the i-th sample cable in the n-th monitoring cycle, c i1 is the insulation resistance change of the ith sample cable in the first monitoring cycle, c i2 is the insulation resistance change of the ith sample cable in the second monitoring cycle, c in is the insulation resistance change of the i-th sample cable in the n-th monitoring cycle, A i1 is the cable antioxidant performance evaluation value of the ith sample cable in the first monitoring cycle, A i2 is the cable antioxidant performance evaluation value of the ith sample cable in the second monitoring cycle, A inis the cable antioxidant performance evaluation value of the i-th sample cable in the n-th monitoring cycle, B i1 is the cable waterproof performance evaluation value of the ith sample cable in the first monitoring cycle, B i2 is the cable waterproof performance evaluation value of the ith sample cable in the second monitoring cycle, B in is the cable waterproof performance evaluation value of the i-th sample cable in the n-th monitoring cycle, C i1 is the cable aging performance evaluation value of the first monitoring cycle of the i-th sample cable, C i2 is the cable aging performance evaluation value of the second monitoring cycle of the i-th sample cable, C in It is the cable aging performance evaluation value of the i-th sample cable in the n-th monitoring cycle.

[0109] The working principle and beneficial effects of the above technical solution are as follows: by constructing a comprehensive performance evaluation matrix, multiple performance indicators of each sample cable under different monitoring cycles can be displayed in an intuitive way. Such a comprehensive evaluation matrix can help researchers and engineers to more comprehensively understand the performance of the sample cables and compare and evaluate them. By analyzing and comparing the matrix, the cable with the best performance can be selected as a replacement cable, thereby improving the reliability and service life of the cable system.

[0110] Example 8

[0111] On the basis of Example 1, based on the comprehensive performance evaluation matrix corresponding to each monitoring period of each sample cable, the comprehensive performance evaluation value of each sample cable is calculated, and a replacement cable is selected based on the comprehensive performance evaluation value of each sample cable, including:

[0112] S61. Based on the comprehensive performance evaluation matrix corresponding to each monitoring period of each sample cable, obtain the main influencing value and the secondary influencing value of the comprehensive performance evaluation value of each sample cable;

[0113] S62, calculating the comprehensive performance evaluation value of each sample cable based on the main influencing value of the comprehensive performance evaluation value of each sample cable and the secondary influencing value of the comprehensive performance evaluation value;

[0114] S63, comparing the comprehensive performance evaluation value of each sample cable, selecting the sample cables with the top two comprehensive performance evaluation values, comparing the total cost of laying and subsequent maintenance of the two sample cables, and if the difference between the total cost of laying and subsequent maintenance of the two sample cables is less than the preset cost difference, selecting the sample cable with the top one as the replacement cable;

[0115] Otherwise, the second-ranked sample cable is selected as the replacement cable.

[0116] Preferably, step S61 includes:

[0117] Delete each type of performance evaluation value and its corresponding monitoring data from the performance comprehensive evaluation matrix element corresponding to each monitoring cycle of each sample cable to obtain an evaluation matrix for each type of performance;

[0118] If the rank of the evaluation matrix of each type of performance of the sample cable is greater than the preset threshold of the corresponding type of performance evaluation value, then the performance evaluation value of the corresponding type in the last cycle of the sample cable is used as the main influencing value of the comprehensive performance evaluation value; otherwise, it is used as the secondary influencing value of the comprehensive performance evaluation value.

[0119] Preferably, the comprehensive performance evaluation value of each sample cable is calculated based on the main influencing value of the comprehensive performance evaluation value of each sample cable and the secondary influencing value of the comprehensive performance evaluation value:

[0120] in, is the comprehensive performance evaluation value of the i-th sample cable, u is the total number of main influencing values ​​of the comprehensive performance evaluation value of the i-th sample cable, χ j is the jth main influencing value of the comprehensive performance evaluation value of the i-th sample cable, e is a natural number, and its value is 2.71, Y k It is the secondary influence value of the kth comprehensive performance evaluation value of the comprehensive performance evaluation value of the ith sample cable.

[0121] The working principle and beneficial effects of the above technical solution are as follows: first, based on the comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable, the main influencing value and the secondary influencing value of the comprehensive performance evaluation value of each sample cable are determined; by deleting each performance evaluation value and its corresponding monitoring data in the comprehensive performance evaluation matrix of each sample cable, the evaluation matrix of each type of performance is obtained; according to the comparison result of the rank of each type of performance evaluation matrix with a preset threshold, the main influencing value and the secondary influencing value of the comprehensive performance evaluation value of each sample cable are determined; based on the main influencing value and the secondary influencing value of the comprehensive performance evaluation value of each sample cable, the comprehensive performance evaluation value of each sample cable is calculated; according to the calculation method in formula (4), the main influencing value and the secondary influencing value are combined to obtain the comprehensive performance evaluation value of each sample cable; the comprehensive performance evaluation value of each sample cable is compared; the sample cables with the top two comprehensive performance evaluation values ​​are selected; then, the total cost of laying and subsequent maintenance of the two sample cables is compared; if the difference between the total cost of laying and subsequent maintenance of the two sample cables is less than the preset cost difference, the sample cable ranked first is selected as the replacement cable. Otherwise, select the second-ranked sample cable as the replacement cable. Through this method, a replacement cable that better meets the requirements can be selected based on the comprehensive performance evaluation value. At the same time, by considering the total cost of laying and subsequent maintenance, performance and economy can be comprehensively considered to select the optimal replacement cable solution, thereby improving the reliability and economic benefits of the cable system.

[0122] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for selecting a replacement cable, characterized in that: The following steps are involved: S1. Obtaining rated parameters of the cable to be replaced, and calculating the conductor shielding field strength of the cable to be replaced and the insulation shielding field strength of the cable to be replaced based on the rated parameters of the cable to be replaced; S2. Collect environmental parameters of the construction environment and determine the limiting conditions of the current construction environment based on the collected results; S3. Based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced, the insulation shielding field strength of the cable to be replaced and the restrictive conditions under the current construction environment, a preliminary screening is performed from the existing optional cables to obtain a sample cable set; S4. Perform a performance test on the sample cables, collect the physical parameters of each sample cable in each monitoring cycle during the test, and obtain all types of performance evaluation values ​​of each sample cable in each monitoring cycle based on the physical parameters of each sample cable in each monitoring cycle during the test; S5. Based on the physical parameters of each sample cable in each monitoring cycle during the test and all types of performance evaluation values ​​of each monitoring cycle, a comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable is constructed; S6. Based on the comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable, calculate the comprehensive performance evaluation value of each sample cable, and select a replacement cable based on the comprehensive performance evaluation value of each sample cable.

2. A method for selecting a replacement cable according to claim 1, characterized in that: The rated parameters of the cable to be replaced are obtained, and based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced and the insulation shielding field strength of the cable to be replaced are calculated, including: Conductor shielding field strength of the cable to be replaced: Insulation shielding field strength of the cable to be replaced: Among them, E max is the conductor shielding field strength of the cable to be replaced, E min is the insulation shielding field strength of the cable to be replaced, U0 is the rated voltage of the cable to be replaced, D is the insulation outer radius of the cable to be replaced, d is the insulation inner radius of the cable to be replaced, and Ln is the logarithm with base e.

3. A method for selecting a replacement cable according to claim 1, characterized in that: Collect environmental parameters of the construction environment and determine the constraints of the current construction environment based on the collected results, including: S21. Collect the temperature and humidity of the construction environment, the pH value of the cable contact environment, and the external forces on the cables; S22, judging the restrictive conditions in the current construction environment based on the collected temperature, humidity, pH value of the cable contact environment, external force on the cable and preset reference ambient temperature, preset reference ambient humidity, preset reference pH value of the cable contact environment, and preset reference external force on the cable; S23. Based on the constraints in the current construction environment, an upper limit value of the constraints is given.

4. A method for selecting a replacement cable according to claim 3, characterized in that: Step S22 includes: Compare the difference between the temperature of the construction environment and the preset reference environment temperature, the difference between the humidity of the construction environment and the preset reference environment humidity, the difference between the pH value of the cable contact environment in the construction environment and the preset reference cable contact environment pH value, and the difference between the external force of the cable in the construction environment and the preset reference cable; If the difference between the temperature of the construction environment and the preset reference environment temperature is greater than the preset temperature difference, the temperature adaptability of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the temperature adaptability range of the cable. If the difference between the construction environment humidity and the preset reference environment humidity is greater than the preset humidity difference, the waterproof performance of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the waterproof performance range of the cable. If the difference between the pH value of the cable contact environment in the construction environment and the preset reference cable contact environment pH value is greater than the preset pH value difference, the corrosion resistance of the cable is used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the corrosion resistance range of the cable. If the difference between the external force applied to the cable in the construction environment and the external force applied to the preset reference cable is greater than the preset external force difference, the mechanical strength performance of the cable will be used as one of the restriction conditions. At this time, the upper limit value of the restriction condition is the mechanical strength range of the cable.

5. A method for selecting a replacement cable according to claim 1, characterized in that: Based on the rated parameters of the cable to be replaced, the conductor shielding field strength of the cable to be replaced, the insulation shielding field strength of the cable to be replaced and the constraints in the current construction environment, a preliminary screening is performed from the existing optional cables to obtain a sample cable set, including: S31. Select a cable with the same rated parameters as the cable to be replaced from the available optional cables as a preliminary screening cable; S32, selecting cables whose conductor shielding field strength and insulation shielding field strength are both higher than those of the cables to be replaced from the cables in the primary preliminary screening, as cables for the secondary preliminary screening; S33. Screen out cables that meet the upper limit value of the restriction condition from the secondary preliminary screening cables as a sample cable set.

6. A method for selecting a replacement cable according to claim 1, characterized in that: Step S4 includes: S41, laying each sample cable in a simulated construction environment arranged in advance in the same way as the replacement cable, and simulating the transmission signal of the cable to be replaced during actual working, and connecting each sample cable to an energy spectrum analyzer, a moisture tester, and an insulation resistance tester; The environmental parameters of the simulated construction environment are the same as the laying environmental parameters of the cable to be replaced; S42. Collect the percentage of copper oxygen content of each sample cable in each monitoring cycle during the test by using an energy spectrum analyzer; The moisture content of each cable connector end of each sample during each monitoring cycle during the test is collected by a moisture tester; The insulation resistance change of each sample cable in each monitoring cycle during the test is collected by an insulation resistance tester; S43. Input the percentage of copper oxygen content of each sample cable in each monitoring cycle during the test, the moisture content of each sample cable connector in each monitoring cycle during the test, and the change in insulation resistance of each sample cable in each monitoring cycle during the test into the trained cable antioxidant performance evaluation model, cable waterproof performance evaluation model, and cable aging performance evaluation model, respectively, to obtain the cable antioxidant performance evaluation value, cable waterproof performance evaluation value, and cable aging performance evaluation value of each sample cable in each monitoring cycle.

7. A method for selecting a replacement cable according to claim 6, characterized in that: Based on the physical parameters of each sample cable in each monitoring cycle during the test and all types of performance evaluation values ​​of each monitoring cycle, a comprehensive performance evaluation matrix corresponding to each sample cable in each monitoring cycle is constructed: in, is the comprehensive performance evaluation matrix corresponding to the i-th sample cable, a i1 is the percentage of copper oxygen content in the first monitoring cycle of the i-th sample cable, a i2 is the percentage of copper oxygen content in the second monitoring cycle of the i-th sample cable, a in is the percentage of copper oxygen content in the i-th sample cable in the n-th monitoring cycle, b i1 is the moisture content at the cable joint of the ith sample cable in the first monitoring cycle, b i2 is the moisture content at the cable joint of the ith sample cable in the second monitoring cycle, b in is the moisture content at the cable joint end of the i-th sample cable in the n-th monitoring cycle, c i1 is the insulation resistance change of the i-th sample cable in the first monitoring cycle, c i2 is the insulation resistance change of the ith sample cable in the second monitoring cycle, c in is the insulation resistance change of the i-th sample cable in the n-th monitoring cycle, A i1 is the cable antioxidant performance evaluation value of the ith sample cable in the first monitoring cycle, A i2 is the cable antioxidant performance evaluation value of the ith sample cable in the second monitoring cycle, A in is the cable antioxidant performance evaluation value of the i-th sample cable in the n-th monitoring cycle, B i1 is the cable waterproof performance evaluation value of the ith sample cable in the first monitoring cycle, B i2 is the cable waterproof performance evaluation value of the ith sample cable in the second monitoring cycle, B in is the cable waterproof performance evaluation value of the i-th sample cable in the n-th monitoring cycle, C i1 is the cable aging performance evaluation value of the first monitoring cycle of the i-th sample cable, C i2 is the cable aging performance evaluation value of the second monitoring cycle of the i-th sample cable, C in It is the cable aging performance evaluation value of the i-th sample cable in the n-th monitoring cycle.

8. A method for selecting a replacement cable according to claim 1, characterized in that: Based on the comprehensive performance evaluation matrix corresponding to each monitoring cycle of each sample cable, the comprehensive performance evaluation value of each sample cable is calculated, and a replacement cable is selected based on the comprehensive performance evaluation value of each sample cable, including: S61. Based on the comprehensive performance evaluation matrix corresponding to each monitoring period of each sample cable, obtain the main influencing value and the secondary influencing value of the comprehensive performance evaluation value of each sample cable; S62, calculating the comprehensive performance evaluation value of each sample cable based on the main influencing value of the comprehensive performance evaluation value of each sample cable and the secondary influencing value of the comprehensive performance evaluation value; S63, comparing the comprehensive performance evaluation value of each sample cable, selecting the sample cables with the top two comprehensive performance evaluation values, comparing the total cost of laying and subsequent maintenance of the two sample cables, and if the difference between the total cost of laying and subsequent maintenance of the two sample cables is less than the preset cost difference, selecting the sample cable with the top one as the replacement cable; Otherwise, the second-ranked sample cable is selected as the replacement cable.

9. A method for selecting a replacement cable according to claim 8, characterized in that: Step S61 includes: Delete each type of performance evaluation value and its corresponding monitoring data from the performance comprehensive evaluation matrix element corresponding to each monitoring cycle of each sample cable to obtain an evaluation matrix for each type of performance; If the rank of the evaluation matrix of each type of performance of the sample cable is greater than the preset threshold of the corresponding type of performance evaluation value, then the performance evaluation value of the corresponding type in the last cycle of the sample cable is used as the main influencing value of the comprehensive performance evaluation value; otherwise, it is used as the secondary influencing value of the comprehensive performance evaluation value.

10. A replacement cable selection method according to claim 1, characterized in that: The comprehensive performance evaluation value of each sample cable is calculated based on the main influencing value of the comprehensive performance evaluation value of each sample cable and the secondary influencing value of the comprehensive performance evaluation value: in, is the comprehensive performance evaluation value of the i-th sample cable, u is the total number of main influencing values ​​of the comprehensive performance evaluation value of the i-th sample cable, χ j is the jth main influencing value of the comprehensive performance evaluation value of the i-th sample cable, e is a natural number, and its value is 2.71, Y k It is the secondary influence value of the kth comprehensive performance evaluation value of the comprehensive performance evaluation value of the ith sample cable.

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