Method, system and equipment for evaluating performance of copper-aluminum transition splicing sleeve under long-term working condition

Abstract

The invention provides a copper-aluminum transition splicing sleeve performance evaluation method, system and equipment under a long-term working condition, and the method comprises the steps: carrying out the material performance test of a to-be-tested pipe, and obtaining a material performance evaluation result; placing the plurality of to-be-tested tubes in a multi-loop parallel large-current test structure for synchronous electrical contact performance test, and performing temperature bidirectional compensation to obtain an electrical contact performance evaluation result; performing a stability simulation test on the to-be-tested pipe to obtain a long-term operation reliability evaluation result; synthesizing the three evaluation results of the to-be-tested pipe to obtain a comprehensive evaluation result of the to-be-tested pipe; according to the method and system, overall performance evaluation is achieved by comprehensively considering the aspects of material performance, electrical contact performance and long-term operation reliability, then temperature bidirectional compensation is carried out on the electrical contact performance of the multi-loop parallel large-current test structure, so that the precision of an electrical contact performance evaluation result is improved, local evaluation is achieved, and the reliability of the test structure is improved. And a set of complete high-precision copper-aluminum transition splicing sleeve performance evaluation method is formed.

Description

Technical Field

[0001] The present invention belongs to the technical field of performance evaluation of electrical engineering materials, and particularly relates to a method, system and equipment for evaluating the performance of copper-aluminum transition connecting pipes under long-term working conditions. Background Art

[0002] Copper-clad aluminum composite material is a kind of bimetallic composite material, which combines the excellent electrical conductivity of copper and the characteristics of low cost and light weight of aluminum. With the continuous progress of material preparation and processing technology, copper-clad aluminum composite materials are gradually developing towards high performance and integrated structural functions, and have become one of the key basic materials for lightweight, performance improvement, cost reduction and efficiency increase in fields such as communication navigation, new energy power generation, aerospace, rail transit, and electrical equipment. In the field of electric power, the transition joints made of copper-clad aluminum composite materials have the advantages of low transition resistance, low thermal resistance, strong corrosion resistance, good ductility and formability. Compared with pure copper busbars under the same current-carrying conditions, the comprehensive cost can be reduced by more than 20-30% during the whole life cycle. In the future, with the continuous construction of new energy supporting projects for power grids such as wind power and photovoltaic, and the continuous increase of the price of electrical engineering copper, high-performance copper-clad aluminum composite materials will have broad application prospects in the power industry, and the direct economic benefits will be more significant. However, at present, there is a lack of a systematic method for evaluating the performance of copper-aluminum transition connecting pipes in the industry, especially there are obvious deficiencies in the performance evaluation and reliability verification under long-term operating conditions. To develop long-term stable and reliable copper-aluminum transition connecting pipes for power cables, it is crucial to select suitable connector materials. Therefore, it is of great significance to establish a scientific and complete evaluation system. Summary of the Invention

[0003] To overcome the deficiencies of the above-mentioned prior art, the present invention proposes a method for evaluating the performance of copper-aluminum transition connecting pipes under long-term working conditions, including:

[0004] Conduct material performance tests on multiple test pipes of copper-aluminum transition connecting pipes respectively to obtain the material performance test results of each test pipe, and input the material performance test results of each test pipe into the material performance evaluation model to obtain the material performance evaluation results of each test pipe;

[0005] Place the multiple test pipes in a large-current test structure with multiple parallel circuits, synchronously conduct electrical contact performance tests to obtain the electrical contact performance test results of the multiple test pipes, and use a temperature compensation system to perform two-way temperature compensation on the electrical contact performance test results of the multiple test pipes to obtain the compensation results of the multiple test pipes, and input the compensation results of each test pipe into the electrical performance evaluation model to obtain the electrical contact performance evaluation results of each test pipe;

[0006] Place each of the tubes to be tested in a long-term operation simulation condition for stability simulation testing, obtain the simulation test results of each tube to be tested, and input the simulation test results of each tube to be tested into a reliability evaluation model to obtain the long-term operation reliability evaluation results of each tube to be tested;

[0007] Based on each tube to be tested, comprehensively consider the material property evaluation results, electrical contact property evaluation results, and long-term operation reliability evaluation results of the tube to be tested to obtain the comprehensive evaluation results of the tube to be tested.

[0008] Preferably, placing the multiple tubes to be tested in a large current test structure with multiple parallel circuits for synchronous electrical contact performance testing includes:

[0009] Place the multiple tubes to be tested in multiple parallel test circuits in the large current test structure, and apply a set test current to each tube to be tested synchronously through each test circuit; an electromagnetic shielding layer is provided between each test circuit.

[0010] Based on each tube to be tested, use the voltage measurement module in the large current test structure to measure the voltage difference between the whole tube to be tested and a locally set area, and calculate the resistance of the whole tube to be tested and the resistance of the locally set area according to the voltage difference to complete the electrical contact performance testing.

[0011] Preferably, the set test current includes multi-level stable currents and pulsed currents of different frequencies;

[0012] The locally set area includes the copper-aluminum interface transition area and the crimping deformation area of the tube to be tested.

[0013] Preferably, based on each tube to be tested, using the voltage measurement module in the large current test structure to measure the voltage difference between the whole tube to be tested and a locally set area includes:

[0014] Based on each tube to be tested, use the voltage measurement module in the large current test structure to move two probes in the voltage measurement module to contact both ends of the tube to be tested or both ends of the locally set area respectively, and measure the voltage difference between both ends of the tube to be tested or the voltage difference between both ends of the locally set area through a differential amplifier circuit connected to the probes;

[0015] Among them, the probe includes a probe body, and the end of the probe body for contact is a gold-plated contact end, and the probe body has an S-shaped elastic section.

[0016] Preferably, using a temperature compensation system to perform two-way temperature compensation on the electrical contact performance test results of the multiple tubes to be tested to obtain the compensation results of the multiple tubes to be tested includes:

[0017] Based on the main measurement circuit and the reference circuit in the temperature compensation system, measure the temperature of the test area covering all test loops and the ambient temperature, and calculate the temperature change rate of the test area and the ambient temperature change rate according to the temperature of the test area and the ambient temperature; the main measurement circuit includes a temperature sensor array arranged in the test area.

[0018] Based on the temperature change rate of the test area and the ambient temperature change rate, use the piecewise linear interpolation algorithm to calculate the temperature compensation value of the test area and the ambient temperature compensation value respectively.

[0019] Based on the historical test area temperature data and the historical ambient temperature data, correct the temperature compensation value of the test area and the ambient temperature compensation value respectively to obtain the corrected temperature compensation value of the test area and the corrected ambient temperature compensation value.

[0020] Based on the data fusion algorithm, fuse the corrected temperature compensation value of the test area and the corrected ambient temperature compensation value to obtain the comprehensive temperature compensation value.

[0021] Based on the relationship between temperature and resistance, use the comprehensive temperature compensation value to compensate the resistance of the whole of the multiple tubes to be tested and the resistance of a locally set area to obtain the compensation results of the multiple tubes to be tested; wherein, the relationship between temperature and resistance is established based on the polynomial fitting algorithm.

[0022] Preferably, inputting the compensation result of each tube to be tested into the electrical performance evaluation model to obtain the electrical contact performance evaluation result of each tube to be tested includes:

[0023] Construct an electrical evaluation index set based on the contact resistance index, temperature rise characteristic index and load capacity index of the tube to be tested.

[0024] Based on each tube to be tested, take the compensation result of the tube to be tested as the value of the contact resistance index, take the resistance change rate calculated according to the compensation result as the value of the load capacity index, and take the temperature change rate of the test area as the value of the temperature rise characteristic index.

[0025] Taking the value of the electrical evaluation index set as the input, output the electrical contact performance evaluation result of the tube to be tested through the electrical performance evaluation model.

[0026] Preferably, the material performance tests on multiple tubes to be tested of the copper-aluminum transition joint tube include:

[0027] Obtain the material specimens of each tube to be tested of the copper-aluminum transition joint tube.

[0028] Conduct tensile property tests, hardness tests and microstructure analyses on the material specimens of each tube to be tested.

[0029] Preferably, obtaining the material samples of each test tube of the copper-aluminum transition connecting tube includes:

[0030] Based on each test tube of the copper-aluminum transition connecting tube, according to the set hyperbolic equation, determine the hyperbolic profile between the clamping section and the gauge section of the material sample of the test tube, and manufacture the transition section of the material sample according to the hyperbolic profile;

[0031] Open gradient spiral grooves in the length direction of the clamping section, and the groove depth of the gradient spiral grooves gradually decreases towards the direction close to the transition section.

[0032] Preferably, placing each of the test tubes in a long-term operation simulation condition respectively, conducting a stability simulation test, obtaining the simulation test results of each test tube, and inputting the simulation test results of each test tube into a reliability evaluation model to obtain the long-term operation reliability evaluation results of each test tube, including:

[0033] Based on each of the test tubes, place the test tube in a variety of long-term operation simulation conditions;

[0034] Based on each long-term operation simulation condition, according to the long-term change trend of the resistance of the obtained test tube, calculate the resistance change rate and the fluctuation coefficient to obtain the electrical performance stability of the test tube under the long-term operation simulation condition;

[0035] According to the surface temperature of the obtained test tube, determine the temperature rise change law and the temperature distribution uniformity of the test tube to obtain the thermal characteristic stability of the test tube under the long-term operation simulation condition;

[0036] According to the surface stress of the obtained test tube, determine the structural adaptability of the test tube under the long-term operation simulation condition;

[0037] Input the electrical performance stability, thermal characteristic stability and structural adaptability of the test tube under a variety of long-term operation simulation conditions into a reliability evaluation model to obtain the long-term operation reliability evaluation results of the test tube;

[0038] The long-term operation simulation conditions include multiple ones among the rated load operation condition, the temperature cycle condition and the load fluctuation condition.

[0039] Preferably, based on each of the test tubes, comprehensively considering the material performance evaluation results, electrical contact performance evaluation results and long-term operation reliability evaluation results of the test tube to obtain the comprehensive evaluation results of the test tube, including:

[0040] Based on each of the tubes to be tested, when any one of the material property evaluation result, the electrical contact property evaluation result, and the long-term operation reliability evaluation result of the tube to be tested does not meet the set standard, the comprehensive evaluation result of the tube to be tested is determined as unqualified;

[0041] When the material property evaluation result, the electrical contact property evaluation result, and the long-term operation reliability evaluation result of the tube to be tested all meet the set standards, the material property evaluation result, the electrical contact property evaluation result, and the long-term operation reliability evaluation result are weighted and summed to obtain the comprehensive evaluation result of the tube to be tested; wherein, the weights of the long-term operation reliability evaluation result, the electrical contact property evaluation result, and the material property evaluation result decrease in sequence.

[0042] Based on the same inventive concept, the present invention further provides a performance evaluation system for copper-aluminum transition connecting tubes under long-term working conditions, including:

[0043] A material property evaluation module, configured to perform various material property tests on the tubes to be tested of the copper-aluminum transition connecting tubes, input the results of the various material property tests into a material property evaluation model, and obtain the material property evaluation results of the tubes to be tested;

[0044] An electrical contact property evaluation module, configured to place multiple tubes to be tested in a large-current test structure with multiple parallel circuits, perform electrical contact property tests synchronously, and use a temperature compensation system to perform two-way temperature compensation on the test results output by the large-current test structure, input the compensation results into an electrical property evaluation model, and obtain the electrical contact property evaluation results of multiple tubes to be tested;

[0045] A long-term operation reliability evaluation module, configured to place the tubes to be tested in various long-term operation simulation conditions, perform stability simulation tests, input the simulation test results into a reliability evaluation model, and obtain the long-term operation reliability evaluation results of the crimped copper-aluminum transition connecting tubes;

[0046] A data comprehensive processing module, configured to comprehensively process the material property evaluation results, the electrical contact property evaluation results, and the long-term operation reliability evaluation results of the tubes to be tested, and obtain the comprehensive evaluation results of the tubes to be tested.

[0047] Preferably, the electrical contact property evaluation module includes:

[0048] A current application unit, configured to place the multiple tubes to be tested in multiple parallel test circuits in the large-current test structure respectively, and synchronously apply a set test current to each tube to be tested through each test circuit; an electromagnetic shielding layer is provided between each test circuit;

[0049] A resistance measurement unit is configured to measure the voltage difference between the whole of the device under test and a locally set area based on each device under test, using the voltage measurement module in the high-current test structure, and calculate the resistance of the whole of the device under test and the resistance of the locally set area according to the voltage difference, thereby completing the electrical contact performance test.

[0050] Preferably, the set test current includes multiple levels of stable current and pulsed currents of different frequencies;

[0051] The locally set area includes the copper-aluminum interface transition area and the crimping deformation area of the device under test.

[0052] Preferably, the resistance measurement unit is specifically configured to:

[0053] Based on each device under test, using the voltage measurement module in the high-current test structure, move two probes in the voltage measurement module to contact the two ends of the device under test or the two ends of the locally set area respectively, and measure the voltage difference between the two ends of the device under test or the voltage difference between the two ends of the locally set area through a differential amplifier circuit connected to the probes;

[0054] Among them, the probe includes a probe body, and the end of the probe body for contact is a gold-plated contact end, and the probe body has an S-shaped elastic section.

[0055] Preferably, the electrical contact performance evaluation module further includes:

[0056] A temperature measurement unit is configured to measure the temperature of the test area covering all test loops and the ambient temperature based on the main measurement circuit and the reference circuit in the temperature compensation system, and calculate the temperature change rate of the test area and the temperature change rate of the ambient temperature according to the temperature of the test area and the ambient temperature; the main measurement circuit includes a temperature sensor array arranged in the test area;

[0057] A compensation value calculation unit is configured to calculate a test area temperature compensation value and an ambient temperature compensation value respectively using a piecewise linear interpolation algorithm based on the temperature change rate of the test area and the temperature change rate of the ambient temperature;

[0058] A correction value calculation unit is configured to correct the test area temperature compensation value and the ambient temperature compensation value respectively based on historical test area temperature data and historical ambient temperature data to obtain a test area temperature compensation correction value and an ambient temperature compensation correction value;

[0059] A data fusion unit is configured to perform data fusion on the test area temperature compensation correction value and the ambient temperature compensation correction value based on a data fusion algorithm to obtain a comprehensive temperature compensation value;

[0060] A temperature compensation unit, which is used to compensate the resistance of the whole of the multiple tubes under test and the resistance of a locally set area based on the relationship between temperature and resistance by using the comprehensive temperature compensation value, so as to obtain compensation results of the multiple tubes under test; wherein, the relationship between temperature and resistance is established based on a polynomial fitting algorithm.

[0061] Preferably, the electrical contact performance evaluation module further includes:

[0062] An index construction unit, which is used to construct an electrical evaluation index set based on the contact resistance index, temperature rise characteristic index and load capacity index of the tubes under test;

[0063] An index value acquisition unit, which is used to, based on each tube under test, use the compensation result of the tube under test as the value of the contact resistance index, use the resistance change rate calculated according to the compensation result as the value of the load capacity index, and use the temperature change rate of the test area as the value of the temperature rise characteristic index;

[0064] An electrical performance evaluation unit, which is used to take the values of the electrical evaluation index set as inputs and output the electrical contact performance evaluation results of the tubes under test through an electrical performance evaluation model.

[0065] Preferably, the material performance evaluation module includes:

[0066] A specimen acquisition unit, which is used to acquire material specimens of each tube under test of the copper-aluminum transition connecting tube;

[0067] A material performance testing unit, which is used to perform tensile property testing, hardness testing and microstructure analysis on the material specimens of each tube under test.

[0068] Preferably, the specimen acquisition unit is specifically used for:

[0069] Based on each tube under test of the copper-aluminum transition connecting tube, according to a set hyperbolic equation, determine the hyperbolic contour between the clamping section and the gauge section of the material specimen of the tube under test, and manufacture the transition section of the material specimen according to the hyperbolic contour;

[0070] Open gradient spiral grooves in the length direction of the clamping section, and the groove depth of the gradient spiral grooves gradually decreases towards the direction close to the transition section.

[0071] Preferably, the long-term operation reliability evaluation module is specifically used for:

[0072] Based on each tube under test, place the tube under test in a variety of long-term operation simulation conditions;

[0073] Based on each long-term operation simulation condition, according to the long-term change trend of the resistance of the pipe to be measured obtained, calculate the resistance change rate and the fluctuation coefficient, and obtain the electrical performance stability of the pipe to be measured under the long-term operation simulation condition;

[0074] According to the surface temperature of the pipe to be measured obtained, determine the temperature rise change law and the temperature distribution uniformity of the pipe to be measured, and obtain the thermal characteristic stability of the pipe to be measured under the long-term operation simulation condition;

[0075] According to the surface stress of the pipe to be measured obtained, determine the structural adaptability of the pipe to be measured under the long-term operation simulation condition;

[0076] Input the electrical performance stability, thermal characteristic stability and structural adaptability of the pipe to be measured under multiple long-term operation simulation conditions into the reliability evaluation model, and obtain the long-term operation reliability evaluation result of the pipe to be measured;

[0077] The long-term operation simulation conditions include multiple of rated load operation condition, temperature cycle condition and load fluctuation condition.

[0078] Preferably, the data comprehensive processing module is specifically used for:

[0079] Based on each of the pipes to be measured, when any one of the material performance evaluation result, electrical contact performance evaluation result and long-term operation reliability evaluation result of the pipe to be measured does not meet the set standard, make the comprehensive evaluation result of the pipe to be measured unqualified;

[0080] When the material performance evaluation result, electrical contact performance evaluation result and long-term operation reliability evaluation result of the pipe to be measured all meet the set standards, perform a weighted sum of the material performance evaluation result, the electrical contact performance evaluation result and the long-term operation reliability evaluation result to obtain the comprehensive evaluation result of the pipe to be measured; wherein, the weights of the long-term operation reliability evaluation result, the electrical contact performance evaluation result and the material performance evaluation result decrease in turn.

[0081] Based on the same inventive concept, the present invention also provides a computer device, including: one or more processors;

[0082] A memory for storing one or more programs;

[0083] When the one or more programs are executed by the one or more processors, implement a method for evaluating the performance of a copper-aluminum transition connecting pipe under a long-term condition as described above.

[0084] Based on the same inventive concept, the present invention also provides a computer-readable storage medium with a computer program stored thereon. When the computer program is executed, it realizes a method for evaluating the performance of a copper-aluminum transition connecting pipe under long-term working conditions as described above.

[0085] Compared with the closest prior art, the present invention has the following beneficial effects:

[0086] The present invention provides a method and system for evaluating the performance of a copper-aluminum transition connecting pipe under long-term working conditions, including: respectively performing material property tests on multiple test pipes of the copper-aluminum transition connecting pipe to obtain the material property test results of each test pipe, inputting the material property test results of each test pipe into a material property evaluation model to obtain the material property evaluation results of each test pipe; placing the multiple test pipes in a large current test structure with multiple parallel circuits to synchronously perform electrical contact property tests to obtain the electrical contact property test results of the multiple test pipes, and using a temperature compensation system to perform two-way temperature compensation on the electrical contact property test results of the multiple test pipes to obtain the compensation results of the multiple test pipes, inputting the compensation results of each test pipe into an electrical property evaluation model to obtain the electrical contact property evaluation results of each test pipe; placing each test pipe in a long-term operation simulation working condition to perform a stability simulation test to obtain the simulation test results of each test pipe, inputting the simulation test results of each test pipe into a reliability evaluation model to obtain the long-term operation reliability evaluation results of each test pipe; based on each test pipe, comprehensively considering the material property evaluation results, electrical contact property evaluation results and long-term operation reliability evaluation results of the test pipe to obtain the comprehensive evaluation results of the test pipe; the method and system achieve overall performance evaluation by comprehensively considering from aspects of material properties, electrical contact properties and long-term operation reliability, and achieve local evaluation by determining the material property evaluation results according to the material property test results, determining the long-term operation reliability evaluation results according to the stability simulation test results under the long-term operation simulation working condition, and performing two-way temperature compensation on the electrical contact properties of the large current test structure with multiple parallel circuits to improve the accuracy of the electrical contact property evaluation results, etc. The above process reflects a hierarchical evaluation strategy from the whole to the part, and the organic combination of these methods forms a complete and high-precision method for evaluating the performance of a copper-aluminum transition connecting pipe. Description of the Drawings

[0087] Figure 1 It is a schematic flow chart of a method for evaluating the performance of a copper-aluminum transition connecting pipe under long-term working conditions provided by the present invention;

[0088] Figure 2 It is a schematic structural diagram of a material sample provided by the present invention;

[0089] Figure 3Schematic diagram of the comparison of the cross-sectional dimensions of the clamping section, gauge section, transition section, and gauge section provided by the present invention;

[0090] Figure 4 Schematic diagram of the relationship between the curvature radius of the transition section and the actual radius of the transition section provided by the present invention;

[0091] Figure 5 Schematic diagram of the structure of the clamping section of the material specimen provided by the present invention;

[0092] Figure 6 Schematic diagram of the cross-sectional structure of the clamping section of the material specimen provided by the present invention;

[0093] Figure 7 Schematic diagram of the structure of the electrical contact performance test system provided by the present invention;

[0094] Figure 8 Schematic diagram of the differential amplifier circuit structure provided by the present invention;

[0095] Figure 9 Schematic diagram of the probe structure provided by the present invention;

[0096] Figure 10 Schematic diagram of the structure of the temperature compensation system provided by the present invention;

[0097] Figure 11 Schematic diagram of the principle of long-term operation reliability evaluation provided by the present invention;

[0098] Figure 12 Schematic diagram of the structure of a performance evaluation system for copper-aluminum transition connecting pipes under long-term working conditions provided by the present invention;

[0099] Figure 13 Schematic diagram of the structure of an electronic device provided by the present invention. Detailed implementation manners

[0100] The following further elaborates on the detailed implementation manners of the present invention with reference to the accompanying drawings.

[0101] Example 1:

[0102] A method for evaluating the performance of copper-aluminum transition connecting pipes under long-term working conditions provided by the present invention, as Figure 1 shown, includes:

[0103] S1. Conduct material property tests on multiple test pipes of the copper-aluminum transition connecting pipe respectively to obtain the material property test results of each test pipe, and input the material property test results of each test pipe into the material property evaluation model to obtain the material property evaluation results of each test pipe;

[0104] S2. Place multiple tubes to be tested in a large-current test structure with multiple parallel circuits, conduct electrical contact performance tests synchronously, obtain the electrical contact performance test results of multiple tubes to be tested, and use a temperature compensation system to perform two-way temperature compensation on the electrical contact performance test results of multiple tubes to be tested to obtain the compensation results of multiple tubes to be tested. Input the compensation result of each tube to be tested into the electrical performance evaluation model to obtain the electrical contact performance evaluation result of each tube to be tested;

[0105] S3. Place each tube to be tested in a long-term operation simulation condition respectively, conduct a stability simulation test, obtain the simulation test result of each tube to be tested, and input the simulation test result of each tube to be tested into the reliability evaluation model to obtain the long-term operation reliability evaluation result of each tube to be tested;

[0106] S4. Based on each tube to be tested, comprehensively consider the material performance evaluation result, electrical contact performance evaluation result and long-term operation reliability evaluation result of the tube to be tested to obtain the comprehensive evaluation result of the tube to be tested.

[0107] Considering that there is currently a lack of a systematic method for evaluating the performance of copper-aluminum transition connecting tubes, especially there are obvious deficiencies in the performance evaluation and reliability verification under long-term operation conditions. The present invention realizes the overall performance evaluation by comprehensively considering from aspects of material performance, electrical contact performance and long-term operation reliability. By determining the material performance evaluation result according to the material performance test result, determining the long-term operation reliability evaluation result according to the stability simulation test result under long-term operation simulation conditions, and performing two-way temperature compensation on the electrical contact performance of the large-current test structure with multiple parallel circuits to improve the accuracy of the electrical contact performance evaluation result, etc., to realize the local evaluation. The above process reflects the hierarchical evaluation strategy from the whole to the local. The organic combination of these methods forms a complete and high-precision method for evaluating the performance of copper-aluminum transition connecting tubes.

[0108] First of all, in terms of material performance evaluation, the present invention adopts innovative specimen design and testing methods. Material performance evaluation is a systematic analysis and evaluation of the performance of materials under various environmental conditions, and this process is crucial for ensuring that the materials of copper-aluminum transition connecting tubes can meet the requirements of specific applications.

[0109] In this embodiment, when performing material performance tests on multiple tubes to be tested of the copper-aluminum transition connecting tube in the above S1, it may include:

[0110] Obtain the material specimens of each tube to be tested of the copper-aluminum transition connecting tube;

[0111] Perform tensile property tests, hardness tests and microstructure analyses on the material specimens of each tube to be tested.

[0112] Considering the problems that the existing material specimens are prone to uneven stress distribution and excessive clamping force leading to excessive deformation during testing, when obtaining the material specimens in the above S1, different from the traditional arc transition section structure, a transition section with a hyperbolic profile is set between the clamping section and the gauge section, which can reduce the stress concentration coefficient from the traditional 1.08 to 1.02, improve the strain uniformity of the gauge section, reduce the strain distribution deviation of the gauge section by 50%, and at the same time improve the controllability of the specimen fracture position, so that more than 90% of the material specimens fracture in the middle of the gauge section, making the test results more accurate. In addition, gradient spiral grooves are provided in the clamping section. When the test fixture clamps the clamping section, the friction between the clamping section and the test fixture is increased, so as to provide better clamping force and avoid excessive deformation of the material specimen; the groove depth of some gradient spiral grooves near the transition section is smaller, which can avoid affecting the overall structure of the transition section and the gauge section, thus further ensuring the uniformity of the stress distribution during the test process.

[0113] Exemplarily, the present invention focuses on the research of the contact and long-term behavior of a new type of copper-aluminum transition joint tube for power cables. The research object is the crimp-type current-carrying connectors (copper-aluminum transition joint tubes) supporting three innovative aluminum alloy power cable conductors, with the models being EN AW-5754, EN AW-6082, and EN AW-2007 respectively.

[0114] In this embodiment, when obtaining the material specimens of each test tube of the copper-aluminum transition joint tube in the above S1, it may include:

[0115] Based on each test tube of the copper-aluminum transition joint tube, according to the set hyperbolic equation, determine the hyperbolic profile between the clamping section and the gauge section of the material specimen of the test tube, and fabricate the transition section of the material specimen according to the hyperbolic profile;

[0116] Gradient spiral grooves are opened in the length direction of the clamping section, and the groove depth of the gradient spiral grooves gradually decreases towards the direction close to the transition section.

[0117] It should be noted that as Figure 2 and Figure 3 shown, the structure of the material specimen includes a gauge section, two clamping sections respectively arranged at both ends of the gauge section, and a transition section arranged between the clamping section and the gauge section;

[0118] Among them, as Figure 4 shown, the transition section is a structure based on an optimized curve, and the outer contour adopts a special hyperbolic equation, and the entire transition section contour is defined by the hyperbolic equation. The hyperbolic equation is expressed as:

[0119] y = ±[(D - d) / 2]×[1 - (x / L) 2 ^(1 / 2);

[0120] Where: D is the diameter of the clamping section, d is the diameter of the gauge section, L is the length of the transition section, x is the distance from any point P on the center line of the transition section to the section of the transition section close to the clamping section; y is the radius value at the corresponding point of x, that is, the current radius of the transition section where point P is located, which is used to describe and determine the profile of the transition section, and represents the radial deviation value at any point of the transition section; Point P slides between the starting end P1 and the ending end P2 of the transition section.

[0121] Exemplarily, the ratio of the length L of the transition section to the diameter difference (D - d) is 2.5:1, and the ratio of the length L of the gauge section o to the diameter d of the gauge section is 5:1. The relationship between the curvature radius R of the transition section and the diameter difference (D - d) is R = (D - d) × 2.5;

[0122] Wherein, R is the curvature radius of the transition section, that is, a physical quantity describing the degree of curve bending. A larger R value indicates a gentler transition, and a smaller R value indicates a steeper transition. The R value is controlled by the proportional relationship with (D - d);

[0123] Through finite element analysis and optimization, such a structural dimension design realizes that the stress concentration coefficient Kt of the transition section ≤ 1.02, the deviation of the stress distribution uniformity of the gauge section ≤ 0.5%, and the stress gradient at the end ≤ 5 MPa / mm; thereby reducing the stress concentration coefficient, improving the strain uniformity of the gauge section, reducing the deviation of the strain distribution of the gauge section, and at the same time improving the controllability of the specimen fracture position.

[0124] When opening the gradient spiral groove, the depth of the spiral groove gradually decreases from the end to the middle, and the angle is kept at 45°. This structure not only ensures the clamping force but also avoids excessive deformation.

[0125] Specifically, as Figure 5 shown, the gradient spiral groove structure of the clamping section includes two parallel spiral grooves. The groove depth of the spiral groove gradually decreases from the end far from the gauge section to the middle. The relationship between the groove depths d1, d2, and d3 of the spiral groove is: d1 > d2 > d3; as shown in Figures 5 and Figure 6 shown, it shows the overall trend of the spiral structure, the distribution of the spiral grooves on the circular cross-section of the clamping section, the angle of the spiral groove, and the changing trend of the groove depth;

[0126] Exemplarily, the number of spiral grooves is 2, the spiral angle remains unchanged at 45°, the groove depth gradually decreases from the end to the middle, and the gradual change range of the groove depth is 0.5 mm to 1.5 mm, that is, the depths d1, d2, and d3 take values within the range of 0.5 mm to 1.5 mm;

[0127] In addition, the present invention adopts a dual surface treatment scheme of ultrasonic cleaning and plasma activation in the surface treatment process of material specimens, and uses special specimen preparation processes and testing schemes to achieve high-precision characterization of material properties, ensuring the accuracy and repeatability of test results. The specific steps are as follows:

[0128] First, clean with ultrasonic waves at a frequency of 40 kHz and a power of 300 W in acetone solution for 10 minutes; then perform surface activation treatment with argon plasma at a vacuum degree of 50 Pa for 5 minutes; finally, apply a special anti-oxidation coating with a thickness of 2 μm.

[0129] In terms of specimen size control, the present invention adopts a composite processing technology combining laser cutting and precision machining. First, perform rough machining with a laser, and then perform finish machining with a precision lathe. Through optimized process parameters, the tolerance of the key dimensions of the specimen is controlled within ±0.01 mm, and the surface roughness reaches Ra≤0.4 μm, which provides guarantee for the accuracy of subsequent tests.

[0130] Furthermore, in terms of tensile property testing, a stress relaxation testing mode with segmented loading is adopted. The specific operation is as follows: during the tensile process of the material specimen, every time the set stress level is reached, such as 20%, 40%, 60%, 80% of the initial yield strength, keep the displacement unchanged, observe the stress relaxation behavior for 60 s, and then continue to load. This testing method can more comprehensively reflect the mechanical property characteristics of the material. At the same time, a high-precision strain measurement system based on fiber Bragg grating is adopted, and the strain measurement accuracy is improved to ±0.1%.

[0131] In terms of hardness testing, a scanning indentation array testing method is adopted. The specific operation is as follows: arrange an indentation array of 15 mm×15 mm on the surface of the material specimen along the radial and axial directions respectively, with an indentation spacing of 0.5 mm. Automatically measure the indentation size through indentation image recognition software, and establish a three-dimensional model of hardness distribution. This method not only improves the testing efficiency, but more importantly, can comprehensively reflect the distribution characteristics of material hardness.

[0132] In terms of microstructure analysis, an in-situ strain-microstructure observation system is adopted, mainly using a micro-tensile stage equipped with a 500-fold microscope and a high-speed camera, which can observe the changes of the microstructure in real time during the loading process. The system adopts a multi-scale characterization method, which can not only observe macroscopic deformation, but also capture microscopic tissue evolution, providing an intuitive basis for understanding material properties.

[0133] The basic mechanical parameters such as tensile strength and elongation at break of the material specimen are determined through tensile property tests. At the same time, the Vickers hardness is measured through hardness tests and microstructure analysis is carried out. This method of material property testing can not only characterize the property differences between different materials, but also reflect the irregularities inside the material, providing a reliable basis for material selection.

[0134] In terms of data acquisition of the material property test results, based on the intelligent data acquisition and processing system, an adaptive sampling algorithm is adopted to automatically adjust the sampling frequency according to the change rate of the test signal, avoiding the generation of redundant data while ensuring data integrity.

[0135] When data processing is carried out after obtaining the material property test results of each material, a multi-parameter evaluation model of material properties based on machine learning, namely the material property evaluation model, is established. This material property evaluation model comprehensively considers multiple parameters such as strength, plasticity, and hardness, and can comprehensively evaluate the material properties.

[0136] The material evaluation method adopted in the present invention achieves the following technical effects:

[0137] 1) Significantly improved test accuracy: Through optimized material specimen design and advanced test methods, the measurement accuracy of tensile strength is increased to ±0.5%, the measurement accuracy of elongation at break is increased to ±0.2%, and the dispersion of hardness measurement is reduced by 50%.

[0138] 2) Greatly improved test efficiency: Thanks to the automated test system and intelligent data processing methods, the test time for a single specimen is shortened by 40%, the data processing time is reduced by 60%, and the overall test throughput is increased by 200%.

[0139] 3) Achieved high reliability of test results: The repeatability of test results reaches more than 95%, the recognition rate of abnormal data reaches 99%, and the stability of the test equipment is increased by 80%. The improvement of these indicators provides a reliable guarantee for material property evaluation.

[0140] Electrical contact performance evaluation is a process for evaluating the quality and reliability of electrical connections, which ensures that contact components in the electrical system, such as copper-aluminum transition joints, can meet the design requirements to guarantee the stability of the circuit and the normal operation of the equipment. In the above S2, by designing a large-current test structure with three parallel circuits, equipped with a high-precision voltage measurement device and a temperature two-way compensation mechanism, the accurate test of the electrical performance of the copper-aluminum transition joint is realized, and an innovative S-shaped flexible probe structure is adopted to solve the technical problem of long-term stable contact. During the test and evaluation process, the influence of the geometric dimension design of the crimp-type current-carrying connection component, that is, the copper-aluminum transition joint, on the electrical contact performance is mainly investigated, and the structural parameters of the crimping sleeve, that is, the copper-aluminum transition joint, that can ensure the best electrical contact performance are determined through systematic experiments.

[0141] Considering the limitations existing in the traditional electrical contact performance test, such as only being able to test a single sample at a time, low test efficiency, long test time, difficulty in comparing the performance of different samples under the same working conditions, and the comparison data between samples may be affected by factors such as test time and environment and thus not be comparable, etc., the present invention synchronously conducts the electrical contact performance test by placing multiple tubes to be tested in a large-current test structure with multi-loop parallel connection, so as to realize the simultaneous test of multiple samples, improve the test efficiency. The synchronous test process can ensure that the test conditions (temperature, humidity, power supply, etc.) are exactly the same, so that the comparison data of multiple samples is more comparable and it is more convenient to conduct the comparison and verification of material properties.

[0142] In this embodiment, when conducting the electrical contact performance test in the above S2, it may include:

[0143] Respectively place multiple tubes to be tested in multiple parallel test loops of the large-current test structure, and synchronously apply a set test current to each tube to be tested through each test loop; an electromagnetic shielding layer is provided between each test loop;

[0144] Based on each tube to be tested, use the voltage measurement module in the large-current test structure to measure the voltage difference between the whole and a locally set area of the tube to be tested, and calculate the resistance of the whole tube to be tested and the resistance of the locally set area according to the voltage difference, so as to complete the electrical contact performance test.

[0145] In this embodiment, the set test current includes multi-level stable currents and pulsed currents with different frequencies;

[0146] The locally set area includes the copper-aluminum interface transition area and the crimping deformation area of the tube to be tested.

[0147] The design of the above electrical contact performance test scheme adopts a hierarchical evaluation strategy. First, measure the overall resistance of the connector, that is, the tube to be tested. The set test current is gradually increased from 100A to 1000A, and the holding time of each level of current is 5 minutes, and the steady-state data is recorded. Then conduct the local resistance measurement, focusing on the resistance distribution in the copper-aluminum interface transition area and the crimping deformation area. Finally, conduct the transient characteristic test. By setting the set test current as pulsed currents with different frequencies, evaluate the performance of the connector under dynamic load, and the frequency range is between 50Hz and 1000Hz, and obtain the resistance change rate of the tube to be tested under pulsed currents with different frequencies according to the resistance change under dynamic load. During the subsequent two-way temperature compensation, by compensating the resistance under dynamic load, recalculate the resistance change rate to obtain the resistance change rate after two-way temperature compensation.

[0148] Specifically, the electromagnetic shielding layer is a magnetic shielding layer made of μ-metal material. The thickness of the magnetic shielding layer is 2 mm, and the magnetic permeability is greater than 50,000, achieving isolation between each test loop and reducing the interference between test loops to below -80 dB.

[0149] Exemplarily, as Figure 7 shown, it shows the core components of the overall electrical contact performance test system, including a large current transformer power supply system, three parallel test loops 1, loop 2, and loop 3, a control system, and a data acquisition system; the control system includes a temperature compensation system; among them, the wiring of each test loop is arranged symmetrically, and each test loop includes an independent current transformer, a sample installation area, a voltage measurement point, and a control unit; the system adopts a star-shaped power distribution structure to ensure the independence and stability of the power supply for each loop; multiple tubes to be tested are placed symmetrically as sample 1, sample 2, and sample 3 in each test loop, minimizing the influence of stray inductance, effectively suppressing the crosstalk between test loops, thus avoiding the electromagnetic interference problem of the large current test structure with multiple loops in parallel and ensuring the test accuracy.

[0150] When applying a set test current to each tube to be tested synchronously through each test loop, a 500 kVA large current transformer is used as the power supply. The secondary side of the transformer supplies power to each test loop through three groups of independent current transformers. An adjustable current device is set in each test loop, and the current magnitude can be continuously adjusted in the range of 0 - 1000 A, so as to ensure the balanced current distribution of the three test loops.

[0151] The above test method using three parallel test loops has about three times higher test efficiency than the traditional single loop test, better consistency of test conditions, more reliable sample comparison data, and can simultaneously obtain multiple groups of data for comparative analysis. Therefore, the multi-loop parallel test not only improves the test efficiency, but more importantly, improves the comparability and reliability of the test results.

[0152] Considering that the electrical contact performance test is greatly affected by temperature and the accuracy of voltage measurement, in terms of voltage measurement, the present invention uses a differential amplifier circuit, a probe, and a temperature compensation system to obtain the electrical contact performance test results.

[0153] In this embodiment, when measuring the voltage difference between the whole and the local set area of the tube to be tested by using the voltage measurement module in the above large current test structure, it may include:

[0154] Based on each tube to be tested, using the voltage measurement module in the large current test structure, move the two probes in the voltage measurement module to contact the two ends of the tube to be tested or the two ends of the local set area respectively, and measure the voltage difference between the two ends of the tube to be tested or the voltage difference between the two ends of the local set area through the differential amplifier circuit connected to the probe.

[0155] Among them, the probe includes a probe body. One end of the probe body for contact is a gold-plated contact end, and the probe body has an S-shaped elastic section.

[0156] Exemplarily, as Figure 8 shown, the differential amplifier circuit takes the high-precision operational amplifier AD8421 as the core, and cooperates with the sampling resistors Rs1 and Rs2 with an accuracy of 0.01%, achieving a microvolt-level measurement resolution. Among them, one end of the sampling resistors Rs1 and Rs2 are the input terminals V1 and V2 respectively. The input terminals are connected to the probe, and the other ends are connected to the operational amplifier AD8421. The output terminal of the operational amplifier AD8421 is Vout. The probe at the measurement end adopts a specially designed flexible probe structure. As Figure 9 shown, the probe body is made of beryllium copper alloy material, with a tensile strength of 450 MPa and good electrical conductivity. The contact end of the probe is plated with a 0.1 μm thick gold layer to form a gold-plated contact end, preventing oxidation and contamination, and ensuring long-term stable contact performance. The elastic section of the probe adopts a special S-shaped structure design to form an S-shaped elastic section. While ensuring a 5N contact pressure, it has a position adjustment margin of ±0.5 mm, controlling the measurement repeatability error within 0.5%, and significantly improving the test efficiency and accuracy.

[0157] Considering that the electrical contact performance test is greatly affected by the accuracy of temperature and voltage measurement, the present invention adopts an improved piecewise linear interpolation algorithm in the design of the temperature compensation system to perform two-way temperature compensation on the electrical contact performance test results. Compared with the problems in the traditional piecewise linear interpolation algorithm, such as possible discontinuity at the piecewise points, insufficient interpolation accuracy in the area with rapid temperature change, and no consideration of the influence of temperature historical data, the temperature compensation system of the present invention performs piecewise interpolation according to the temperature change rate and adds historical data for correction, thereby improving the accuracy of the test results.

[0158] In this embodiment, when using the temperature compensation system to perform two-way temperature compensation on the electrical contact performance test results of multiple tubes to be tested and obtaining the compensation results of multiple tubes to be tested in the above S2, it may include:

[0159] Based on the main measurement circuit and the reference circuit in the temperature compensation system, measure the temperature of the test area covering all test loops and the ambient temperature, and calculate the temperature change rate of the test area and the ambient temperature change rate according to the temperature of the test area and the ambient temperature; the main measurement circuit includes a temperature sensor array arranged in the test area;

[0160] Based on the temperature change rate of the test area and the ambient temperature change rate, calculate the temperature compensation value of the test area and the ambient temperature compensation value respectively by using the piecewise linear interpolation algorithm;

[0161] Based on the historical temperature data of the test area and the historical ambient temperature data, the temperature compensation value of the test area and the ambient temperature compensation value are respectively corrected to obtain the corrected temperature compensation value of the test area and the corrected ambient temperature compensation value;

[0162] Based on the data fusion algorithm, the corrected temperature compensation value of the test area and the corrected ambient temperature compensation value are fused to obtain the comprehensive temperature compensation value;

[0163] Based on the relationship between temperature and resistance, using the comprehensive temperature compensation value, the resistance of the whole of multiple tubes to be measured and the resistance of a locally set area are compensated to obtain the compensation results of the multiple tubes to be measured; among them, the relationship between temperature and resistance is established based on the polynomial fitting algorithm.

[0164] Specifically, the piecewise linear interpolation algorithm adopts an adaptive piecewise strategy, dynamically adjusts the piecewise interval according to the temperature change rate, increases the density of piecewise points at the places where the temperature changes violently, and appropriately reduces the piecewise points in the temperature-stable area to achieve adaptive segmentation;

[0165] Subsequently, a smooth transition function is added at the piecewise points to ensure the continuity of the first derivative, reduce the mutation of the compensation curve, and achieve the smooth transition processing of the piecewise points;

[0166] Fuse the temperature historical data, namely the historical temperature data of the test area and the historical ambient temperature data, to establish a temperature change trend model, and combine the historical data for predictive compensation to improve the dynamic response performance;

[0167] The specific algorithm process includes:

[0168] Input: real-time temperature measurement value T, historical temperature data sequence H;

[0169] Output: compensated temperature value T';

[0170] Step 1: Calculate the temperature change rate dT / dt according to the real-time temperature measurement value T;

[0171] Step 2: Determine the piecewise interval according to the change rate;

[0172] Step 3: Perform linear interpolation on each interval;

[0173] Step 4: Smooth the piecewise points;

[0174] Step 5: Add the historical data, namely the historical temperature data sequence H, for correction;

[0175] Step 6: Output the compensation result, that is, the compensated temperature value T'.

[0176] After the overall compensation is completed, the compensation accuracy can be increased by 50%, the dynamic response time can be shortened by 30%, and the discontinuity at the segmentation point can be reduced by 80%, solving the problems that occur in the traditional piecewise linear interpolation algorithm.

[0177] For example, Figure 10 As shown, in terms of structure, the temperature compensation system includes a main measurement circuit, a reference circuit, and a signal conditioning circuit;

[0178] Twenty PT100 temperature sensors are arranged in the main measurement circuit, forming 20 sampling points, which are distributed in a matrix pattern and cover the entire test area. Each sensor uses a four-wire connection method, with a sensor spacing of 10 mm, and the sensor matrix is distributed to cover the test area;

[0179] For example, the reference circuit is provided with a precision standard resistor with a temperature coefficient of ±0.5 ppm / °C. An excitation current is provided by a high-precision constant current source (stability better than 0.01%), and the voltage change across the standard resistor is monitored in real time to obtain information on the ambient temperature change for use as the ambient temperature reference;

[0180] For example, the signal conditioning circuit uses a high-precision 24-bit ADC (Analog-to-Digital Converter), model ADS1248 for data acquisition, and the temperature measurement accuracy is better than ±0.1°C. The four-wire connection method is used to eliminate the influence of lead resistance. The signal conditioning circuit system also includes a temperature compensation algorithm processing unit and a compensation result output module. The temperature compensation algorithm processing unit uses an improved piecewise linear interpolation algorithm for temperature compensation, and within the range of -20°C to 150°C, the measurement error after compensation is controlled within 0.1%; at the same time, a polynomial fitting algorithm is used to establish the corresponding relationship between temperature and resistance;

[0181] In summary, the temperature compensation system of the present invention adopts a two-way temperature compensation mechanism to achieve a high-precision temperature compensation function. This mechanism realizes precise local temperature monitoring through the PT100 sensor matrix in the main measurement circuit, and at the same time cooperates with the standard resistor in the reference circuit for overall temperature calibration. This two-way compensation structure improves the temperature measurement accuracy to ±0.1°C, and the temperature drift of the measurement system is controlled within 0.1% / °C. Through the optimized design of the temperature compensation algorithm, the system maintains high-precision measurement capabilities within a wide temperature range of -20°C to 150°C, providing a reliable temperature compensation basis for the performance evaluation of connectors. Through the evaluation of this system, the performance of crimped connectors can be accurately judged, providing a reliable basis for the design optimization and quality control of products.

[0182] The two-way temperature compensation technical solution proposed by the present invention specifically includes: the overall architecture design of the two-way temperature compensation system, which realizes high-precision temperature compensation through the cooperation of the main measurement circuit and the reference circuit; the optimized layout scheme of the PT100 sensor matrix, including the spatial distribution of sensors, signal acquisition and processing methods; the improved temperature compensation algorithm based on piecewise linear interpolation, which can achieve high-precision compensation in the range of -20°C to 150°C; the specific implementation technology of the standard resistance reference circuit, including the selection of standard resistors, the design of constant current sources and signal detection schemes.

[0183] In terms of data acquisition, simultaneous measurement of multiple test circuits is carried out through the data acquisition system in the overall test system, so as to ensure the measurement accuracy.

[0184] Specifically, in terms of data acquisition and processing, the data acquisition system adopts a hierarchical architecture design, including a data acquisition layer, a data preprocessing layer, a data analysis layer and a result output layer.

[0185] The data acquisition layer is equipped with a multi-channel synchronous acquisition card with a sampling rate of 1MS / s and a resolution of 16 bits. The collected parameters include voltage, current, temperature and waveform data. For example, the sampling rate of voltage acquisition is 1MS / s, the resolution is 16bit, the current acquisition uses a Hall sensor with a linearity better than 0.1%; the temperature acquisition uses 20 sampling points in parallel; the waveform acquisition supports transient process recording.

[0186] The data preprocessing layer uses wavelet transform for noise filtering and simultaneously performs outlier detection based on the 3σ criterion to standardize the data to ensure comparability.

[0187] In the data analysis layer, a performance evaluation model based on multiple parameters is established, which can also be called an electrical performance parameter evaluation model or an electrical performance evaluation model. The electrical performance evaluation model includes indicators such as contact resistance, temperature rise characteristics, and load capacity. Machine learning algorithms are used for trend analysis and prediction is carried out based on the life stress model.

[0188] In the result output layer, the system displays the test data in real time and automatically generates a test analysis report, including performance parameters, trend charts and warning information.

[0189] The system has shown excellent performance in practical applications: the measurement repeatability error is less than 0.5%, the temperature drift is less than 0.1% / °C, which can meet the requirements of engineering applications. Through the evaluation of this system, the performance of the crimped connectors can be accurately judged, providing a reliable basis for the design optimization and quality control of products.

[0190] Among them, in the data analysis layer, when the compensation results of each test tube are input into the electrical performance evaluation model to obtain the electrical contact performance evaluation results of each test tube, it may include:

[0191] Construct an electrical evaluation index set based on the contact resistance index, temperature rise characteristic index, and load capacity index of the tube under test;

[0192] Based on each tube under test, use the compensation result of the tube under test as the value of the contact resistance index, use the resistance change rate calculated based on the compensation result as the value of the load capacity index, and use the temperature change rate of the test area as the value of the temperature rise characteristic index;

[0193] Take the value of the electrical evaluation index set as the input, and output the electrical contact performance evaluation result of the tube under test through the electrical performance evaluation model.

[0194] In summary, the electrical performance test system of the present invention focuses on protecting the following technical solutions: the structural design of the three-loop parallel test system, including key technologies such as power distribution, current control, and signal isolation; the implementation technology of the μ-metal magnetic shielding layer, involving shielding material selection, hierarchical structure design, and installation method; the design scheme of the differential voltage measurement circuit, including operational amplifier selection, circuit layout, and anti-interference measures; the innovative structure of the S-shaped flexible probe, including probe material, geometric dimensions, and surface treatment process, which solves the technical problem of long-term stable contact.

[0195] Considering that in the traditional long-term operation reliability assessment process, usually only electrical performance (such as contact resistance) and temperature characteristics are mainly concerned, which cannot directly reflect the internal stress state of the material and are difficult to predict the trend of mechanical property deterioration. However, in fact, for connectors such as crimp-type copper-aluminum transition joints, stress changes also have an important impact on the long-term reliability of the connectors; for example, stress changes such as thermal stress accumulation caused by temperature cycling, stress generated by electromagnetic force during the current-carrying process, fatigue stress caused by mechanical vibration, residual stress during the crimping process, and stress relaxation caused by material creep. Introducing a stress monitoring system can real-time monitor the stress state changes of the connectors, warn of potential mechanical failure risks, and provide more comprehensive data support for life prediction. Therefore, the long-term operation reliability assessment method provided by the present invention conducts long-term tests on the crimp connection of cable conductors by simulating actual operating conditions to evaluate its stability under operating load. In the above S3, by continuously monitoring the change of the joint resistance, the electrical performance stability of the connector is evaluated to achieve the long-term stability assessment of the joint resistance; by observing the temperature change at the connection under the condition of simulating the actual operating load, its thermal stability is verified to achieve the temperature performance assessment; by conducting comparative tests on various connection designs, the performance differences of different structural designs are evaluated to achieve the comparison of multiple design schemes; by simulating various possible operating conditions (such as load fluctuations, ambient temperature changes, etc.), the adaptability of the connector is comprehensively evaluated to achieve the assessment of the adaptability of operating conditions; by simulating actual operating conditions, long-term performance monitoring and evaluation of the connector are carried out to comprehensively verify its operating stability and environmental adaptability.

[0196] Specifically, when performing the long-term operation reliability assessment for the above S3, it may include:

[0197] Based on each device under test, place the device under test in a variety of long-term operation simulation conditions;

[0198] Based on each long-term operation simulation condition, according to the long-term change trend of the resistance of the device under test obtained, calculate the resistance change rate and the fluctuation coefficient, and obtain the electrical performance stability of the device under test under the long-term operation simulation condition;

[0199] According to the surface temperature of the device under test obtained, determine the temperature rise change law and the temperature distribution uniformity of the device under test, and obtain the thermal characteristic stability of the device under test under the long-term operation simulation condition;

[0200] According to the surface stress of the device under test obtained, determine the structural adaptability of the device under test under the long-term operation simulation condition;

[0201] Input the electrical performance stability, thermal characteristic stability, and structural adaptability of the device under test under a variety of long-term operation simulation conditions into the reliability assessment model to obtain the long-term operation reliability assessment result of the device under test;

[0202] The long-term operation simulation conditions include multiple ones among the rated load operation condition, the temperature cycle condition, and the load fluctuation condition.

[0203] Exemplarily, as Figure 11 shown, in terms of the condition simulation design of the long-term operation simulation conditions, the present invention has established three typical operation conditions. First is the rated load operation condition. By applying an adjustable rated current of 500A - 1000A to the connecting piece, a long-term current-carrying test is realized, and the test time is not less than 5000 hours.

[0204] Second is the temperature cycle condition. The temperature range is set from -40°C to 150°C, each cycle period is 4 hours, which includes 1 hour of high-temperature holding and 1 hour of low-temperature holding, and the temperature rise and fall rate is controlled at 5°C / min, and the number of cycles is not less than 1000 times. Finally is the load fluctuation condition. Under the condition of the basic current-carrying, that is, 0.6 times the rated current, a periodic fluctuation of 0.2 times the rated current is superimposed, the fluctuation period is 10 minutes, and the duration is not less than 2000 hours.

[0205] The present invention adopts a multi-dimensional monitoring scheme for real-time parameter monitoring. In terms of electrical performance monitoring, a high-precision micro-ohmmeter is used to regularly measure the joint resistance, and the measurement point is set 1 cm away from the end of the joint. The micro-ohm level measurement accuracy is achieved through the four-terminal method. For temperature monitoring, a T-type thermocouple array is adopted, and 12 temperature measurement points are evenly arranged on the surface of the connector to accurately obtain the temperature field distribution. At the same time, a stress monitoring system is introduced to continuously monitor the stress state change at the connection through a strain gauge array, providing a basis for evaluating the mechanical performance.

[0206] In terms of constructing the comprehensive performance evaluation system, the present invention conducts a comprehensive evaluation from three dimensions: electrical performance stability, thermal characteristic stability, and structural adaptability. The electrical performance stability mainly examines the long-term change trend of the joint resistance, and a stability evaluation model based on time series analysis is established. This model quantitatively evaluates the electrical performance stability of the connector by calculating the resistance change rate and the fluctuation coefficient. The thermal characteristic stability evaluation adopts the temperature field analysis method, and evaluates the thermal stability performance of the connector by monitoring the temperature rise change law and the temperature distribution uniformity. The structural adaptability evaluation focuses on the adaptability of the connector under different working conditions, including temperature cycle adaptability, load fluctuation adaptability, etc.

[0207] The present invention also establishes a complete data analysis and evaluation system. The system uses high-speed data acquisition equipment with a sampling frequency of up to 1 kHz to achieve continuous monitoring of parameters. In terms of data processing, the analysis software can realize the automatic acquisition, storage, and analysis of test data. By establishing a performance degradation model, the life prediction and reliability evaluation of the connector are realized. At the same time, the system has a real-time monitoring and warning function. When the monitored parameters exceed the preset range, a warning message is automatically sent.

[0208] In summary, the long-term operation reliability evaluation method provided by the present invention first systematically designs a variety of typical working conditions, namely a variety of long-term operation simulation working conditions, to comprehensively simulate the actual operation environment; secondly, establishes a multi-dimensional parameter monitoring system to comprehensively characterize the performance of the connector; finally, constructs a complete long-term operation reliability evaluation index system. The indexes in the long-term operation reliability evaluation index system include electrical performance stability, thermal characteristic stability, and structural adaptability, providing a reliable basis for product performance evaluation. Through the application of this method, the long-term operation reliability of the crimp-type copper-aluminum transition joint can be accurately evaluated, providing important support for product design optimization and engineering applications.

[0209] The present invention also provides an intelligent data processing system based on a hierarchical architecture, which realizes the full-automatic management of the testing process. The system adopts high-speed sampling of 1MS / s and high resolution of 16 bits, and cooperates with an improved wavelet transform filtering algorithm to effectively improve the data quality. The innovative multi-parameter evaluation model comprehensively analyzes indicators such as resistance, temperature rise, and load capacity, and realizes performance prediction and life assessment through machine learning algorithms. The system has real-time monitoring and intelligent warning functions, with the data processing efficiency increased by 200% and the abnormal recognition accuracy reaching 99%, providing comprehensive technical support for product optimization and quality control. This innovative data processing solution makes the performance evaluation of the crimp-type copper-aluminum transition connecting pipe more accurate, efficient, and intelligent, and has significant engineering application value.

[0210] Considering that the performance evaluation results of the copper-aluminum transition connecting pipe are ultimately used to guide the selection, the long-term reliability of the copper-aluminum transition connecting pipe in use ultimately determines the product service life, the electrical contact performance ensures the realization of the basic functions, and the material performance is a necessary condition but not a sufficient condition; therefore, the importance of the above three performances is ranked as: long-term operation reliability > electrical contact performance > material performance, so as to obtain the comprehensive evaluation result.

[0211] In the above S4, when obtaining the comprehensive evaluation result of the pipe to be tested, it may include:

[0212] Based on each pipe to be tested, when any one of the material performance evaluation result, electrical contact performance evaluation result, and long-term operation reliability evaluation result of the pipe to be tested does not meet the set standard, the comprehensive evaluation result of the pipe to be tested is determined to be unqualified;

[0213] When the material performance evaluation result, electrical contact performance evaluation result, and long-term operation reliability evaluation result of the pipe to be tested all meet the set standards, the material performance evaluation result, electrical contact performance evaluation result, and long-term operation reliability evaluation result are weighted and summed to obtain the comprehensive evaluation result of the pipe to be tested; among them, the weights of the long-term operation reliability evaluation result, electrical contact performance evaluation result, and material performance evaluation result decrease in turn.

[0214] Exemplarily, the weight of the long-term operation reliability evaluation result is 50%, the weight of the electrical contact performance evaluation result is 30%, and the weight of the material performance evaluation result is 20%.

[0215] On this basis, determine the strategy for guiding the selection, specifically including:

[0216] (1) Hierarchical screening method: The first level: the material performance meets the standard; the second level: the electrical contact performance is qualified; the third level: the long-term reliability meets the requirements;

[0217] (2) When there are differences in the results: If the long-term reliability evaluation result is the best, it shall be preferentially adopted; if the electrical performance and material performance results are similar, the electrical performance shall prevail; when all indicators are similar, factors such as cost shall be considered comprehensively;

[0218] (3) Specific selection suggestions: The basic requirements of material performance must be met; the electrical contact performance should reach the design standard; long-term reliability is the ultimate determining factor.

[0219] The present invention realizes the systematization and standardization of the performance evaluation of copper-aluminum transition connecting pipes, providing reliable technical support for the performance optimization and quality control of power cable connectors. By establishing a complete evaluation system, it can effectively predict and ensure the reliability of connectors during long-term operation, which is of great significance for improving the safe and stable operation of power systems.

[0220] Embodiment 2:

[0221] Based on the same inventive concept, the present invention also provides a performance evaluation system for copper-aluminum transition connecting pipes under long-term working conditions, as Figure 12 shown, including:

[0222] A material performance evaluation module, configured to perform various material performance tests on a to-be-tested pipe of a copper-aluminum transition connecting pipe, input the results of the various material performance tests into a material performance evaluation model, and obtain a material performance evaluation result of the to-be-tested pipe;

[0223] An electrical contact performance evaluation module, configured to place multiple to-be-tested pipes in a large-current test structure with multiple parallel circuits, synchronously perform electrical contact performance tests, and use a temperature compensation system to perform two-way temperature compensation on the test results output by the large-current test structure, input the compensated results into an electrical performance evaluation model, and obtain electrical contact performance evaluation results of the multiple to-be-tested pipes;

[0224] A long-term operation reliability evaluation module, configured to place the to-be-tested pipe in various long-term operation simulation conditions, perform stability simulation tests, input the simulation test results into a reliability evaluation model, and obtain a long-term operation reliability evaluation result of a crimped copper-aluminum transition connecting pipe;

[0225] A data comprehensive processing module, configured to comprehensively process the material performance evaluation result, electrical contact performance evaluation result, and long-term operation reliability evaluation result of the to-be-tested pipe to obtain a comprehensive evaluation result of the to-be-tested pipe.

[0226] In this embodiment, the electrical contact performance evaluation module includes:

[0227] A current application unit, configured to place multiple to-be-tested pipes in multiple parallel test circuits in a large-current test structure respectively, and synchronously apply a set test current to each to-be-tested pipe through each test circuit; an electromagnetic shielding layer is provided between each test circuit;

[0228] A resistance measurement unit is configured to measure the voltage difference between the whole and a locally set area of a device under test based on each device under test, using a voltage measurement module in a large current test structure, and calculate the resistance of the whole device under test and the resistance of the locally set area according to the voltage difference, thereby completing the electrical contact performance test.

[0229] In this embodiment, the set test current includes multi-level stable currents and pulsed currents with different frequencies.

[0230] The locally set area includes the copper-aluminum interface transition area and the crimping deformation area of the device under test.

[0231] In this embodiment, the resistance measurement unit is specifically configured to:

[0232] Based on each device under test, using the voltage measurement module in the large current test structure, move two probes in the voltage measurement module to contact the two ends of the device under test or the two ends of the locally set area respectively, and measure the voltage difference between the two ends of the device under test or the voltage difference between the two ends of the locally set area through a differential amplifier circuit connected to the probes.

[0233] Among them, the probe includes a probe body, and the end of the probe body for contact is a gold-plated contact end, and the probe body has an S-shaped elastic section.

[0234] In this embodiment, the electrical contact performance evaluation module further includes:

[0235] A temperature measurement unit is configured to measure the temperature of the test area covering all test circuits and the ambient temperature based on the main measurement circuit and the reference circuit in the temperature compensation system, and calculate the temperature change rate of the test area and the temperature change rate of the ambient temperature according to the temperature of the test area and the ambient temperature; the main measurement circuit includes a temperature sensor array arranged in the test area.

[0236] A compensation value calculation unit is configured to calculate the temperature compensation value of the test area and the ambient temperature compensation value respectively by using a piecewise linear interpolation algorithm based on the temperature change rate of the test area and the temperature change rate of the ambient temperature.

[0237] A correction value calculation unit is configured to correct the temperature compensation value of the test area and the ambient temperature compensation value respectively based on the historical test area temperature data and the historical ambient temperature data to obtain the temperature compensation correction value of the test area and the temperature compensation correction value of the ambient temperature.

[0238] A data fusion unit is configured to perform data fusion on the temperature compensation correction value of the test area and the temperature compensation correction value of the ambient temperature based on a data fusion algorithm to obtain a comprehensive temperature compensation value.

[0239] A temperature compensation unit, which is used to compensate the resistance of multiple tubes under test as a whole and the resistance of a locally set area based on the relationship between temperature and resistance by using a comprehensive temperature compensation value, so as to obtain the compensation results of multiple tubes under test; wherein, the relationship between temperature and resistance is established based on a polynomial fitting algorithm.

[0240] In this embodiment, the electrical contact performance evaluation module further includes:

[0241] An index construction unit, which is used to construct an electrical evaluation index set based on the contact resistance index, temperature rise characteristic index and load capacity index of the tube under test.

[0242] An index value acquisition unit, which is used to, based on each tube under test, take the compensation result of the tube under test as the value of the contact resistance index, take the resistance change rate calculated according to the compensation result as the value of the load capacity index, and take the temperature change rate of the test area as the value of the temperature rise characteristic index.

[0243] An electrical performance evaluation unit, which is used to take the value of the electrical evaluation index set as the input and output the electrical contact performance evaluation result of the tube under test through an electrical performance evaluation model.

[0244] In this embodiment, the material performance evaluation module includes:

[0245] A specimen acquisition unit, which is used to acquire the material specimens of each tube under test of the copper-aluminum transition joint tube.

[0246] A material performance test unit, which is used to perform tensile performance tests, hardness tests and microstructure analyses on the material specimens of each tube under test.

[0247] In this embodiment, the specimen acquisition unit is specifically used for:

[0248] Based on each tube under test of the copper-aluminum transition joint tube, according to the set hyperbolic equation, determine the hyperbolic contour between the clamping section and the gauge section of the material specimen of the tube under test, and fabricate the transition section of the material specimen according to the hyperbolic contour.

[0249] Open gradient spiral grooves in the length direction of the clamping section, and the groove depth of the gradient spiral grooves gradually decreases towards the direction close to the transition section.

[0250] In this embodiment, the long-term operation reliability evaluation module is specifically used for:

[0251] Based on each tube under test, place the tube under test in a variety of long-term operation simulation conditions.

[0252] Based on each long-term operation simulation condition, calculate the resistance change rate and the fluctuation coefficient according to the long-term resistance change trend of the tube under test obtained, so as to obtain the electrical performance stability of the tube under test under the long-term operation simulation condition.

[0253] Based on the obtained surface temperature of the tube under test, determine the temperature rise change law and temperature distribution uniformity of the tube under test, and obtain the thermal characteristic stability of the tube under test under the long-term operation simulation conditions;

[0254] Based on the obtained surface stress of the tube under test, determine the structural adaptability of the tube under test under the long-term operation simulation conditions;

[0255] Input the electrical performance stability, thermal characteristic stability and structural adaptability of the tube under test under various long-term operation simulation conditions into the reliability evaluation model to obtain the long-term operation reliability evaluation result of the tube under test;

[0256] The long-term operation simulation conditions include multiple ones such as rated load operation conditions, temperature cycle conditions and load fluctuation conditions.

[0257] In this embodiment, the data comprehensive processing module is specifically used for:

[0258] Based on each tube under test, when any one of the material property evaluation result, electrical contact property evaluation result and long-term operation reliability evaluation result of the tube under test does not meet the set standard, the comprehensive evaluation result of the tube under test is determined to be unqualified;

[0259] When the material property evaluation result, electrical contact property evaluation result and long-term operation reliability evaluation result of the tube under test all meet the set standards, the material property evaluation result, electrical contact property evaluation result and long-term operation reliability evaluation result are weighted and summed to obtain the comprehensive evaluation result of the tube under test; among them, the weights of the long-term operation reliability evaluation result, electrical contact property evaluation result and material property evaluation result decrease in turn.

[0260] Embodiment 3

[0261] As Figure 13 shown, the present invention further provides an electronic device, which may be a computer device, a single-chip microcomputer device, a smart mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor and the transceiver component are connected by a bus; the memory can be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory can also be used to store data, and the data can be called and / or modified when the instructions are executed.

[0262] The processor may be a Central Processing Unit (CPU), or it may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a method for evaluating the performance of copper-aluminum transition connecting pipes under a long-term working condition in the above embodiments.

[0263] Embodiment 4

[0264] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device-readable storage medium (Memory). The electronic device-readable storage medium is a memory device in the electronic device, used to store programs and data. It can be understood that the storage medium here can include both the built-in storage medium in the electronic device, and of course, can also include the extended storage medium supported by the electronic device. The storage medium provides a storage space, and this storage space stores the operating system of the terminal. And, in this storage space, there are also stored one or more instructions suitable for being loaded and executed by the processor. These instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory, or a non-volatile memory, such as at least one disk memory. By the processor loading and executing one or more instructions stored in the storage medium, the steps of a method for evaluating the performance of copper-aluminum transition connecting pipes under a long-term working condition in the above embodiments can be implemented.

[0265] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0266] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one or more flows and / or blocks Figure 1 in one or more flows and / or blocks Figure 1 or in one or more blocks.

[0267] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implements the functions specified in one or more flows and / or blocks Figure 1 in one or more flows and / or blocks Figure 1 or in one or more blocks.

[0268] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows and / or blocks Figure 1 in one or more flows and / or blocks Figure 1 or in one or more blocks.

[0269] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the scope of its protection. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that after reading the present invention, various changes, modifications, or equivalent replacements can still be made to the specific implementation manners of the application. However, these changes, modifications, or equivalent replacements are all within the scope of the protection of the claims of the present invention.

Claims

1. A method for evaluating the performance of a copper-aluminum transition joint under long-term working conditions, characterized in that: include: Performing material property tests on multiple tubes to be tested of the copper-aluminum transition joint tubes respectively to obtain material property test results of each tube to be tested, and inputting the material property test results of each tube to be tested into a material property evaluation model to obtain material property evaluation results of each tube to be tested; Placing the multiple tubes to be tested in a multi-loop parallel high-current test structure, and synchronously performing electrical contact performance tests to obtain electrical contact performance test results of the multiple tubes to be tested, and using a temperature compensation system to perform temperature bidirectional compensation on the electrical contact performance test results of the multiple tubes to be tested to obtain compensation results of the multiple tubes to be tested, and inputting the compensation result of each tube to be tested into an electrical performance evaluation model to obtain an electrical contact performance evaluation result of each tube to be tested; Placing each of the tubes to be tested in a long-term operation simulation condition, respectively, and performing a stability simulation test to obtain a simulation test result of each tube to be tested, and inputting the simulation test result of each tube to be tested into a reliability evaluation model to obtain a long-term operation reliability evaluation result of each tube to be tested; Based on each of the tubes to be tested, the material performance evaluation results, electrical contact performance evaluation results and long-term operation reliability evaluation results of the tubes to be tested are comprehensively considered to obtain a comprehensive evaluation result of the tubes to be tested.

2. The method according to claim 1, characterized in that Placing the plurality of tubes to be tested in a multi-circuit parallel high current test structure and simultaneously conducting an electrical contact performance test includes: The plurality of tubes to be tested are respectively placed in a plurality of parallel test loops in the large current test structure, and a set test current is synchronously applied to each tube to be tested through each test loop; an electromagnetic shielding layer is provided between each test loop; Based on each of the tubes to be tested, the voltage measurement module in the high current test structure is used to measure the voltage difference between the entire tube to be tested and a local set area. The resistance of the entire tube to be tested and the resistance of the local set area are calculated based on the voltage difference to complete the electrical contact performance test.

3. The method according to claim 2, characterized in that The set test current includes multi-level stable current and pulse currents of different frequencies; The local setting area includes the copper-aluminum interface transition zone and the crimping deformation zone of the tube to be tested.

4. The method according to claim 2 or 3, characterized in that The method of measuring the voltage difference between the entire tube under test and a local set area of ​​the tube under test by using the voltage measurement module in the high current test structure based on each tube under test includes: Based on each of the tubes to be tested, using the voltage measurement module in the high current test structure, two probes in the voltage measurement module are respectively moved to the two ends of the tube to be tested or the two ends of the local set area to make contact, and the voltage difference between the two ends of the tube to be tested or the two ends of the local set area is measured through a differential amplifier circuit connected to the probes; The probe comprises a probe body, one end of the probe body used for contact is a gold-plated contact end, and the probe body has an S-shaped elastic section.

5. The method according to claim 2 or 3, characterized in that: The temperature compensation system is used to perform temperature bidirectional compensation on the electrical contact performance test results of the multiple tubes to be tested to obtain compensation results of the multiple tubes to be tested, including: Based on the main measurement circuit and the reference circuit in the temperature compensation system, the test area temperature and the ambient temperature covering all the test loops are measured, and the test area temperature change rate and the ambient temperature change rate are calculated according to the test area temperature and the ambient temperature; the main measurement circuit includes a temperature sensor array arranged in the test area; Based on the test area temperature change rate and the ambient temperature change rate, a piecewise linear interpolation algorithm is used to calculate the test area temperature compensation value and the ambient temperature compensation value respectively; Based on the historical test area temperature data and the historical environment temperature data, the test area temperature compensation value and the environment temperature compensation value are respectively corrected to obtain a test area temperature compensation correction value and an environment temperature compensation correction value; Based on a data fusion algorithm, the test area temperature compensation correction value and the ambient temperature compensation correction value are fused to obtain a comprehensive temperature compensation value; Based on the relationship between temperature and resistance, the comprehensive temperature compensation value is used to compensate for the overall resistance of the multiple tubes to be tested and the resistance of the local set area to obtain compensation results of the multiple tubes to be tested; wherein the relationship between temperature and resistance is established based on a polynomial fitting algorithm.

6. The method according to claim 5, characterized in that The step of inputting the compensation result of each tube to be tested into the electrical performance evaluation model to obtain the electrical contact performance evaluation result of each tube to be tested includes: Based on the contact resistance index, temperature rise characteristic index and load capacity index of the tube to be tested, an electrical evaluation index set is constructed; Based on each tube to be tested, the compensation result of the tube to be tested is used as the value of the contact resistance index, the resistance change rate calculated according to the compensation result is used as the value of the load capacity index, and the temperature change rate of the test area is used as the value of the temperature rise characteristic index; The values ​​of the electrical evaluation index set are used as input, and the electrical contact performance evaluation results of the tube to be tested are output through the electrical performance evaluation model.

7. The method according to any one of claims 1 to 3, characterized in that: The material performance tests are respectively performed on the multiple tubes to be tested of the copper-aluminum transition joint tube, including: Obtain material samples of each tube to be tested of the copper-aluminum transition joint tube; A tensile property test, a hardness test and a microstructure analysis are performed on each material sample of the tube to be tested.

8. The method according to claim 7, characterized in that The method of obtaining a material sample of each tube to be tested of the copper-aluminum transition joint tube comprises: Based on each tube to be tested of the copper-aluminum transition joint tube, the hyperbolic profile of the material sample of the tube to be tested between the clamping section and the gauge length section is determined according to a set hyperbolic equation, and the transition section of the material sample is obtained according to the hyperbolic profile; A gradient spiral groove is provided in the length direction of the clamping section, and the groove depth of the gradient spiral groove gradually decreases toward the direction approaching the transition section.

9. The method according to any one of claims 1 to 3, characterized in that: The steps of placing each of the tubes to be tested in a long-term operation simulation condition, performing a stability simulation test, obtaining a simulation test result of each tube to be tested, and inputting the simulation test result of each tube to be tested into a reliability evaluation model to obtain a long-term operation reliability evaluation result of each tube to be tested include: Based on each of the tubes to be tested, placing the tubes to be tested in a variety of long-term operation simulation conditions; Based on each long-term operation simulation condition, the resistance change rate and the fluctuation coefficient are calculated according to the acquired long-term change trend of the resistance of the tube to be tested, so as to obtain the electrical performance stability of the tube to be tested under the long-term operation simulation condition; According to the acquired surface temperature of the tube to be tested, the temperature rise variation law and temperature distribution uniformity of the tube to be tested are determined, and the thermal characteristic stability of the tube to be tested under the long-term operation simulation condition is obtained; Determining the structural adaptability of the pipe to be tested under the long-term operation simulation condition according to the acquired surface stress of the pipe to be tested; Inputting the electrical performance stability, thermal characteristic stability and structural adaptability of the tube to be tested under various long-term operation simulation conditions into a reliability evaluation model to obtain a long-term operation reliability evaluation result of the tube to be tested; The long-term operation simulation conditions include multiple types of rated load operation conditions, temperature cycle conditions and load fluctuation conditions.

10. The method according to any one of claims 1 to 3, characterized in that: Based on each of the tubes to be tested, the material performance evaluation results, electrical contact performance evaluation results and long-term operation reliability evaluation results of the tubes to be tested are comprehensively evaluated to obtain a comprehensive evaluation result of the tubes to be tested, including: Based on each of the tubes to be tested, when any one of the material performance evaluation result, the electrical contact performance evaluation result and the long-term operation reliability evaluation result of the tube to be tested does not meet the set standard, the comprehensive evaluation result of the tube to be tested is considered unqualified; When the material performance evaluation results, electrical contact performance evaluation results and long-term operation reliability evaluation results of the tube to be tested all meet the set standards, the material performance evaluation results, the electrical contact performance evaluation results and the long-term operation reliability evaluation results are weighted and summed to obtain a comprehensive evaluation result of the tube to be tested; wherein the weights of the long-term operation reliability evaluation result, the electrical contact performance evaluation result and the material performance evaluation result decrease in sequence.

11. A long-term working condition crimping type copper-aluminum transition joint evaluation system, characterized in that: include: A material performance evaluation module is used to perform various material performance tests on the copper-aluminum transition joint tube to be tested, input various material performance test results into a material performance evaluation model, and obtain material performance evaluation results of the tube to be tested; An electrical contact performance evaluation module is used to place multiple tubes to be tested in a multi-circuit parallel high-current test structure, perform electrical contact performance tests synchronously, and use a temperature compensation system to perform temperature bidirectional compensation on the test results output by the high-current test structure, input the compensation results into an electrical performance evaluation model, and obtain electrical contact performance evaluation results of the multiple tubes to be tested; The long-term operation reliability assessment module is used to place the pipe to be tested in a variety of long-term operation simulation conditions, conduct stability simulation tests, input the simulation test results into the reliability assessment model, and obtain the long-term operation reliability assessment results of the crimped copper-aluminum transition joint pipe; The data comprehensive processing module is used to comprehensively evaluate the material performance, electrical contact performance and long-term operation reliability of the tube to be tested, so as to obtain a comprehensive evaluation result of the tube to be tested.

12. The system according to claim 11, characterized in that The electrical contact performance evaluation module comprises: A current applying unit is used to place the multiple tubes to be tested in multiple parallel test loops in the large current test structure, and synchronously apply a set test current to each tube to be tested through each test loop; an electromagnetic shielding layer is provided between each test loop; The resistance measuring unit is used to measure the voltage difference between the entire tube to be tested and the local set area based on each of the tubes to be tested by using the voltage measuring module in the high current test structure, and calculate the overall resistance of the tube to be tested and the resistance of the local set area according to the voltage difference to complete the electrical contact performance test.

13. The system of claim 12, wherein: The set test current includes multi-level stable current and pulse currents of different frequencies; The local setting area includes the copper-aluminum interface transition zone and the crimping deformation zone of the tube to be tested.

14. The system according to claim 12 or 13, characterized in that The resistance measuring unit is specifically used for: Based on each of the tubes to be tested, using the voltage measurement module in the high current test structure, two probes in the voltage measurement module are respectively moved to the two ends of the tube to be tested or the two ends of the local set area to make contact, and the voltage difference between the two ends of the tube to be tested or the two ends of the local set area is measured through a differential amplifier circuit connected to the probes; The probe comprises a probe body, one end of the probe body used for contact is a gold-plated contact end, and the probe body has an S-shaped elastic section.

15. The system according to claim 12 or 13, characterized in that The electrical contact performance evaluation module also includes: A temperature measurement unit, for measuring the test area temperature and the ambient temperature covering all test loops based on the main measurement circuit and the reference circuit in the temperature compensation system, and calculating the test area temperature change rate and the ambient temperature change rate according to the test area temperature and the ambient temperature; the main measurement circuit includes a temperature sensor array arranged in the test area; A compensation value calculation unit, used to calculate the test area temperature compensation value and the ambient temperature compensation value respectively by using a piecewise linear interpolation algorithm based on the test area temperature change rate and the ambient temperature change rate; A correction value calculation unit, used to correct the test area temperature compensation value and the ambient temperature compensation value based on historical test area temperature data and historical ambient temperature data, respectively, to obtain a test area temperature compensation correction value and an ambient temperature compensation correction value; A data fusion unit, used for fusing the test area temperature compensation correction value and the ambient temperature compensation correction value based on a data fusion algorithm to obtain a comprehensive temperature compensation value; The temperature compensation unit is used to compensate the overall resistance of the multiple tubes to be tested and the resistance of the local set area based on the relationship between temperature and resistance and adopt the comprehensive temperature compensation value to obtain compensation results of the multiple tubes to be tested; wherein the relationship between temperature and resistance is established based on a polynomial fitting algorithm.

16. The system of claim 15, wherein: The electrical contact performance evaluation module also includes: An index building unit, used to build an electrical evaluation index set based on the contact resistance index, temperature rise characteristic index and load capacity index of the tube to be tested; An index value acquisition unit is used to use, based on each tube to be tested, the compensation result of the tube to be tested as the value of the contact resistance index, the resistance change rate calculated according to the compensation result as the value of the load capacity index, and the test area temperature change rate as the value of the temperature rise characteristic index; The electrical performance evaluation unit is used to take the value of the electrical evaluation index set as input and output the electrical contact performance evaluation result of the tube to be tested through the electrical performance evaluation model.

17. The system according to any one of claims 11 to 13, characterized in that: The material performance evaluation module comprises: A sample acquisition unit, used for acquiring a material sample of each tube to be tested of the copper-aluminum transition joint tube; The material performance testing unit is used to perform tensile performance testing, hardness testing and microstructure analysis on each material sample of the tube to be tested.

18. The system of claim 17, wherein: The sample acquisition unit is specifically used for: Based on each tube to be tested of the copper-aluminum transition joint tube, the hyperbolic profile of the material sample of the tube to be tested between the clamping section and the gauge length section is determined according to the set hyperbolic equation, and the transition section of the material sample is obtained according to the hyperbolic profile; A gradient spiral groove is provided in the length direction of the clamping section, and the groove depth of the gradient spiral groove gradually decreases toward the direction approaching the transition section.

19. The system according to any one of claims 11 to 13, characterized in that: The long-term operation reliability evaluation module is specifically used for: Based on each of the tubes to be tested, placing the tubes to be tested in a variety of long-term operation simulation conditions; Based on each long-term operation simulation condition, the resistance change rate and the fluctuation coefficient are calculated according to the acquired long-term change trend of the resistance of the tube to be tested, so as to obtain the electrical performance stability of the tube to be tested under the long-term operation simulation condition; According to the acquired surface temperature of the tube to be tested, the temperature rise variation law and temperature distribution uniformity of the tube to be tested are determined, and the thermal characteristic stability of the tube to be tested under the long-term operation simulation condition is obtained; Determining the structural adaptability of the pipe to be tested under the long-term operation simulation condition according to the acquired surface stress of the pipe to be tested; Inputting the electrical performance stability, thermal characteristic stability and structural adaptability of the tube to be tested under various long-term operation simulation conditions into a reliability evaluation model to obtain a long-term operation reliability evaluation result of the tube to be tested; The long-term operation simulation conditions include multiple types of rated load operation conditions, temperature cycle conditions and load fluctuation conditions.

20. The system according to any one of claims 11 to 13, characterized in that: The data comprehensive processing module is specifically used for: Based on each of the tubes to be tested, when any one of the material performance evaluation result, the electrical contact performance evaluation result and the long-term operation reliability evaluation result of the tube to be tested does not meet the set standard, the comprehensive evaluation result of the tube to be tested is considered unqualified; When the material performance evaluation results, electrical contact performance evaluation results and long-term operation reliability evaluation results of the tube to be tested all meet the set standards, the material performance evaluation results, the electrical contact performance evaluation results and the long-term operation reliability evaluation results are weighted and summed to obtain a comprehensive evaluation result of the tube to be tested; wherein the weights of the long-term operation reliability evaluation result, the electrical contact performance evaluation result and the material performance evaluation result decrease in sequence.

21. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, a method for evaluating a crimped copper-aluminum transition joint tube under long-term working conditions as described in any one of claims 1 to 10 is implemented.

22. A readable storage medium, characterized in that: An execution program is stored thereon, and when the execution program is executed, a method for evaluating a crimped copper-aluminum transition joint tube under long-term working conditions as described in any one of claims 1 to 10 is implemented.

Images