Method and device for testing reusability of high-voltage cable

Abstract

The invention relates to a method and a device for testing the reusability of a high-voltage cable. The method comprises the following steps: carrying out a bending test on a to-be-tested high-voltage cable; under the condition that M bending tests are completed every time, an electrical performance test and a mechanical performance test are carried out on the high-voltage cable to be tested, an electrical performance test result and a mechanical performance test result are obtained, and M is a positive integer; judging whether the to-be-tested high-voltage cable fails or not according to the electrical performance test result and the mechanical performance test result; and if the test result does not fail, returning to the step of carrying out the bending test on the to-be-tested high-voltage cable, stopping the test until the bending test frequency reaches a preset test frequency or the to-be-tested high-voltage cable fails, integrating all test results, and generating a reusable performance test report. The method is beneficial to improving the reliability of a test result.

Description

Technical Field

[0001] The present application relates to the technical field of cable testing equipment, and in particular to a method and device for testing the reusability performance of a high-voltage cable. Background Art

[0002] In recent years, the problem of prolonged transmission line outages due to UHV construction, municipal relocation, and substation renovations has become prominent, posing risks and challenges to the safe operation of power grids. Therefore, to reduce on-site crossing and spanning construction costs, minimize on-site grid risks and protection costs, and meet the safe power supply needs of key users such as railway users, a reusable temporary short-circuit high-voltage cable has been developed.

[0003] Currently, performance verification of reusable, temporary short-circuit high-voltage cables remains significantly limited. In practical applications, high-voltage cables require frequent installation and removal, and as temporary power supply equipment, they frequently connect and disconnect circuits. However, the accuracy of performance evaluations of these cables in related technologies is insufficient, severely restricting their widespread adoption and application in power engineering.

[0004] Therefore, in order to further improve the performance evaluation system of reusable temporary short-circuit high-voltage cables and ensure their safe and reliable operation under complex working conditions, it is necessary to propose a reliable test method for the reusability performance test of high-voltage cables. Summary of the Invention

[0005] Based on this, it is necessary to provide a high-voltage cable reusability performance testing method and device that can improve the reliability of reusability performance testing in order to address the above technical problems.

[0006] In a first aspect, the present application provides a method for testing the reusability performance of a high-voltage cable, comprising:

[0007] Perform bending test on the high voltage cable to be tested;

[0008] After each M bending test is completed, the electrical performance test and the mechanical performance test are performed on the high-voltage cable to be tested, respectively, to obtain the electrical performance test results and the mechanical performance test results, wherein M is a positive integer;

[0009] Determine whether the high-voltage cable to be tested is faulty based on the electrical performance test results and mechanical performance test results;

[0010] If the high-voltage cable to be tested is not failed, returning to the step of performing a bending test on the high-voltage cable to be tested until the number of bending tests reaches a preset number of test times or the high-voltage cable to be tested fails, and then stopping the test;

[0011] Integrate electrical performance test results and mechanical performance test results to generate reusable performance test reports.

[0012] In a second aspect, the present application further provides a high-voltage cable reusability performance testing device, comprising a master control module, and a bending control module, an electrical performance testing module, and a mechanical performance testing module, each of which is communicatively connected to the master control module.

[0013] A bending control module, used for performing bending tests on the high-voltage cables to be tested;

[0014] Electrical performance test module, used to perform electrical performance test on the high-voltage cable to be tested;

[0015] Mechanical properties test module, used to perform mechanical properties test on the high-voltage cable to be tested;

[0016] The master control module is used to control the bending control module, the electrical performance test module and the mechanical performance test module to perform a reusable performance test on the high-voltage cable to be tested based on the steps in any of the above-mentioned high-voltage cable reusable performance test method embodiments to obtain the reusable performance test results.

[0017] The above-mentioned high-voltage cable reusability performance test method takes into account the usage characteristics of reusable temporary short-circuit high-voltage cables in actual applications and proposes a targeted reusability performance test method. By performing a bending test on the high-voltage cable to be tested, the bending conditions of the cable during use are simulated, which helps to verify its reliability and durability. After each M bending test, the high-voltage cable to be tested is simultaneously subjected to electrical performance test and mechanical performance test. On the one hand, the complex working conditions such as repeated bending, power on and off of the cable during actual use are simulated to obtain electrical performance test results and mechanical performance test results. This is conducive to evaluating the reusability performance of the high-voltage cable to be tested based on the electrical performance test results and mechanical performance test results, thereby improving the reliability of the test and evaluation. On the other hand, it speeds up the process of reusability performance test and improves the test efficiency. Therefore, by cycling the above-mentioned tests, it is conducive to comprehensively assessing the durability of the cable. Furthermore, it is conducive to predicting the maximum number of reuses of the high-voltage cable based on the pre-assessed reusability performance of the high-voltage cable, thereby reducing construction delays and grid safety risks caused by cable failure, and helping to promote the application of reusable cables in ultra-high voltage projects.

[0018] The aforementioned high-voltage cable reusability performance test device, taking into account the significant differences in the reusability performance of reusable temporarily short-circuited high-voltage cables under different operating conditions, proposes a reusable performance test device with a modular integrated design. The device includes a bending control module, an electrical performance test module, and a mechanical performance test module, which are respectively used to perform bending tests, electrical performance tests, and mechanical performance tests on high-voltage cables, thereby reducing the time cost associated with test switching. The master control module controls the bending control module, electrical performance test module, and mechanical performance test module to collaboratively perform automated, multi-dimensional performance testing, thereby improving the accuracy and test efficiency of the high-voltage cable's reusability performance test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A diagram showing an application environment of a method for testing the reusability of a high-voltage cable in one embodiment;

[0021] Figure 2 1 is a flow chart of a method for testing the reusability of a high-voltage cable in one embodiment;

[0022] Figure 3 A schematic flow chart of a method for testing the reusability of a high-voltage cable in a detailed embodiment;

[0023] Figure 4 1. A structural block diagram of a device for testing the reusability of a high-voltage cable according to an embodiment;

[0024] Figure 5 FIG. 4 is a structural block diagram of a device for testing the reusability performance of a high-voltage cable in another embodiment. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0026] The high voltage cable reusability performance testing method provided in the embodiment of the present application can be applied to Figure 1 In the high-voltage cable reusable performance test system shown in FIG, a host computer 102 communicates with a bending test device 104 , an electrical performance test device 106 , and a mechanical performance test device 108 via a network.

[0027] Specifically, the operator may set the number of tests through the host computer 102. The host computer 102 responds to the reusable performance test instruction initiated by the operator and controls the bending test device 104 to perform a bending test on the high-voltage cable to be tested. After each M bending test is completed, the electrical performance test device 106 and the mechanical performance test device 108 are controlled to perform electrical performance tests and mechanical performance tests on the high-voltage cable to be tested, respectively, to obtain electrical performance test results and mechanical performance test results. Then, the host computer 102 determines whether the high-voltage cable to be tested has failed based on the electrical performance test results and the mechanical performance test results. If it is determined that the high-voltage cable to be tested has failed, the bending test device 104, the electrical performance test device 106, and the mechanical performance test device 108 are controlled to stop the test. If the high-voltage cable to be tested has not failed, the bending test device 104, the electrical performance test device 106, and the mechanical performance test device 108 are controlled to execute the above test steps in a loop until the number of bending tests reaches the preset number of tests.

[0028] The host computer 102 may be, but is not limited to, various personal computers, laptops, smartphones, and tablet computers. The bending test device 104 may include, but is not limited to, a servo motor drive system, a cable bending tester, a tensile tester, or a universal testing machine and fixture. The electrical performance test device 106 is used to test the electrical characteristics of the cable, and the device may include, but is not limited to, a high-voltage power supply (AC / DC), a partial discharge detection device (including an HFCT sensor and a signal conditioning circuit), an insulation resistance tester, a withstand voltage test device (including current and voltage monitoring, a data acquisition card (DAQ), a grounding protection and safety interlock device, etc.). The mechanical performance test device 108 is used to test the mechanical properties of the cable under tension and bending, and the device may include, but is not limited to, a torque sensor, a strain sensor, and a three-dimensional scanner.

[0029] In an exemplary embodiment, Figure 2 As shown, a method for testing the reusability of high-voltage cables is provided. Figure 1 The high-voltage cable reusability performance test system in the example is used as an example to illustrate the following steps (hereinafter referred to as S) S100 to S500. Among them:

[0030] S100, performs bending test on the high voltage cable to be tested.

[0031] The high-voltage cable to be tested may be a temporarily short-circuited high-voltage cable. In other embodiments, the high-voltage cable to be tested may also be other cables such as a high-voltage cable and an ultra-high-voltage cable.

[0032] The bend test applies bending stress to the high-voltage cable under test, causing it to bend to simulate bending conditions that the cable may encounter in actual use, such as natural bending during installation and dynamic bending during equipment movement. It is understood that a single bend test may apply bending stress to all areas of the high-voltage cable under test.

[0033] For example, a pre-test calibration of the high-voltage cable to be tested is performed: the operator pre-sets the bending radius, bending speed, and number of test cycles (number of test cycles) via the host computer. The bending speed is determined based on actual operating conditions, for example, it can be adjusted between 0.1 and 2.0 m / s (meters per second); the bending radius can range from 9D to 25D (D is the outer diameter of the high-voltage cable to be tested); and the number of tests can be determined based on experience. For example, the bending radius is set to 12D (default value), the bending speed is set to 0.5 m / s, and the number of cycles is set to 30.

[0034] The bending test apparatus consists of a robotic arm, an adaptive fixture, a winding wheel, and a winder. The robotic arm is driven by a servo motor, and the winder incorporates a built-in dynamic load cell with a built-in PID control algorithm. This dynamic load cell can apply a dynamic tensile force of 0-50kN to simulate the tension changes during cable installation, record the number of bend tests, and control the winding wheel to adjust the bend radius. The winding wheel is driven by a motor. The adaptive fixture is equipped with a pressure feedback device to prevent axial displacement or torsion of the high-voltage cable under test during testing.

[0035] Pre-test calibration also includes: Before the bending test, the high-voltage cable to be tested is wound onto a take-up reel according to the cable model. The reel is then mounted on the take-up frame using a robotic arm and clamped with an adaptive clamp. The cable reel is then unwound and pulled onto the extension platform using a traction rope and cable connector, and the cable reel is then selected and secured according to the cable model.

[0036] In specific implementation, the bending test device responds to the control instructions of the host computer to perform a bending test on the high-voltage cable to be tested. Specifically:

[0037] The cable bending test motor can rotate forward and reverse. When the motor rotates forward, the cable reel rotates forward; when the motor rotates reverse, the cable reel rotates reverse. The linear speed of the motor's forward / reverse rotation is synchronized with the linear speed of the traction winder. This allows the high-voltage cable under test to perform a reciprocating cycle of reeling and unreeling between the reel and the stretching platform.

[0038] In one exemplary embodiment, the bending test can be performed by a bending test device, such as a cable bending tester. Specifically, the operator sets the bending test parameters of the bending test device in advance on the host computer, including the bending radius, etc. The bending radius can be adjusted according to the test requirements. For example, according to the standard test requirements of power cables (such as the GB / T 11017.1 standard), the bending range is set within the range of 9D to 25D (D is the outer diameter of the cable). Before the bending test, the cable is pre-installed on the fixture of the tester, and both ends of the cable are fixed. During the bending test, the drive motor of the cable bending tester is started to drive the bending mechanism to apply bending stress to the cable according to the set bending test parameters to perform the bending test.

[0039] S200 , performing electrical performance tests and mechanical performance tests on the high-voltage cable to be tested respectively after each completion of M bending tests, to obtain electrical performance test results and mechanical performance test results, wherein M is a positive integer.

[0040] Among them, M is set according to actual needs, M≥5, for example, M can be set to 5 or 10, and there is no unique limit. Electrical performance tests include but are not limited to insulation resistance tests, capacitance tests, and AC withstand voltage tests. Among them, the insulation resistance test is to test the resistance value of the cable insulation material to determine whether the quality of the insulation material meets the use requirements of the cable. The capacitance test is to test the capacitance value of the cable to determine the dielectric quality of the cable and whether there are problems such as insulation aging. Test whether the cable can operate normally under the rated voltage to determine whether the cable has good voltage resistance. The electrical performance test results may include whether different types of electrical performance tests are qualified and the electrical parameters of the high-voltage cable to be tested, such as whether the insulation resistance test is qualified and the resistance value of the high-voltage cable to be tested.

[0041] Mechanical performance testing can include detecting whether the structure of the high-voltage cable under test has deformed. For example, an image acquisition device captures an image of the external structure of the high-voltage cable under test and transmits it to a host computer. The host computer uses a visual algorithm to identify whether the structure of the high-voltage cable under test has deformed. The mechanical performance test results can include whether the structure of the high-voltage cable has deformed.

[0042] In one exemplary embodiment, the operator sets the execution timing of the electrical performance test and the mechanical performance test through the host computer. For example, if M is set to 5, the electrical performance test and the mechanical performance test are performed on the high-voltage cable to be tested after every 5 bending tests are completed to obtain the electrical performance test results and the mechanical performance test results.

[0043] S300: Determine whether the high-voltage cable to be tested is faulty based on the electrical performance test results and the mechanical performance test results.

[0044] In practical applications, the failure judgment condition for the high-voltage cable to be tested may be that at least one of the following conditions is met: the electrical performance test result indicates that the electrical performance of the high-voltage cable to be tested has failed, and the mechanical performance test result indicates that the mechanical performance of the high-voltage cable to be tested has failed. The host computer determines whether the high-voltage cable has failed based on the failure judgment condition. Among them, the electrical performance failure can be the failure of the electrical performance test. For example, following the above steps, the insulation resistance test result indicates that the cable insulation material does not meet the preset cable usage requirements; the capacitance test result indicates that the cable has insulation aging, etc. The mechanical performance failure can be the structural deformation of the high-voltage cable to be tested.

[0045] S400, when the high-voltage cable to be tested is not failed, returning to the step of performing a bending test on the high-voltage cable to be tested, and stopping the test until the number of bending tests reaches a preset number of test times or the high-voltage cable to be tested fails.

[0046] The preset number of tests is set according to the requirements, and the preset number of tests is ≥ 30. If the preset number of tests is set to 30 or 50, this application does not make a sole limitation thereto.

[0047] In actual application, if the high-voltage cable to be tested has not failed, the process returns to the step of performing the bending test on the high-voltage cable to be tested, with reference to the implementation of steps S100 to S300 above. The cable reusability performance test is repeated until the number of bending tests reaches the preset number of tests or the high-voltage cable to be tested fails, at which point the test is stopped.

[0048] S500 integrates electrical performance test results and mechanical performance test results to generate reusable performance test reports.

[0049] In actual applications, the host computer integrates the electrical performance test results and the mechanical performance test results, automatically compares the electrical performance test results and the mechanical performance test results before and after the bending test, determines the data inflection point and marks it, and generates a reusable performance test report. Among them, the data inflection point can be determined by the data that has changed significantly before and after the bending test. It can be for the data collected before and after the bending test, and the data inflection point is determined by the differential method, peak detection, etc. The data in the collected electrical performance test results and mechanical performance test results before and after the bending test are visualized, and a visualization file is generated, and the data inflection point is marked in the visualization file. For example, for the capacitance data in the electrical performance test results, a capacitance curve is generated by the drawing function library, the data inflection point is determined by the differential method, and the data inflection point is marked in the visualized capacitance curve file.

[0050] In the above-mentioned high-voltage cable reusability performance test method, taking into account the use characteristics of reusable temporary short-circuit high-voltage cables in actual applications, a targeted reusability performance test method is proposed. By performing a bending test on the high-voltage cable to be tested, the bending conditions of the cable during use are simulated, which helps to verify its reliability and durability. After each M bending test, the high-voltage cable to be tested is simultaneously subjected to electrical performance test and mechanical performance test. On the one hand, the complex working conditions such as repeated bending, power on and off of the cable during actual use are simulated to obtain electrical performance test results and mechanical performance test results. This is conducive to evaluating the reusability performance of the high-voltage cable to be tested based on the electrical performance test results and mechanical performance test results, thereby improving the reliability of the test and evaluation. On the other hand, it speeds up the process of reusability performance test and improves the test efficiency. Therefore, by cycling the above-mentioned tests, it is conducive to comprehensively assessing the durability of the cable. Further, it is conducive to predicting the maximum number of reuses of the high-voltage cable based on the pre-assessed reusability performance of the high-voltage cable, thereby reducing construction delays and grid safety risks caused by cable failure, and helping to promote the application of reusable cables in ultra-high voltage projects.

[0051] In an exemplary embodiment, performing an electrical performance test on a high-voltage cable to be tested and obtaining an electrical performance test result includes S210 to S240:

[0052] In this embodiment, the electrical performance test includes performing a partial discharge test and a voltage withstand test on the high-voltage cable to be tested.

[0053] S210 , increasing the voltage of the high-voltage cable to be tested to a preset partial discharge detection voltage, maintaining a preset partial discharge detection time, and collecting first current data of the high-voltage cable to be tested.

[0054] The partial discharge detection voltage and the partial discharge detection duration are parameters for performing partial discharge detection on the high-voltage cable under test. The first current data is current data of the high-voltage cable under test collected during the partial discharge detection process.

[0055] In practical applications, the partial discharge detection voltage and duration can be pre-set based on test requirements. For example, a withstand voltage test device can be used to gradually raise the voltage of the high-voltage cable under test to 1.75 U0 (U0 is the rated voltage of the cable) and maintain this voltage for 10 seconds, then slowly lower it to 1.5 U0. During this process, a partial discharge detection sensor, such as a high-frequency current sensor, is used to collect first current data from the high-voltage cable under test. The sensor transmits the collected first current data to a partial discharge signal acquisition unit, which amplifies, filters, and digitizes the received sensor data to ensure signal accuracy and reliability. The processed first current data is then transmitted to a host computer.

[0056] S220: Detect, based on the first current data, whether there is partial discharge in the high-voltage cable to be tested and whether the amount of partial discharge exceeds a preset partial discharge amount threshold, to obtain a partial discharge detection result.

[0057] The partial discharge detection result may include whether partial discharge exists in the high-voltage cable to be tested, and whether the amount of partial discharge exceeds a preset partial discharge amount threshold.

[0058] In practical applications, determining whether partial discharge exists in the high-voltage cable under test can be done by determining, based on the first current data, whether the current of the high-voltage cable under test exceeds a preset current threshold. This current threshold is set according to standard testing requirements for power cables. If the host computer detects that the current exceeds the preset current threshold, partial discharge is determined to exist in the high-voltage cable under test, and the amount of partial discharge is determined based on the first current data. In one exemplary embodiment, the amount of partial discharge can be determined based on the first current data by measuring the amount of partial discharge using a partial discharge tester. Assuming the partial discharge threshold is 5 pC (picocoulomb), the measured partial discharge amount is compared with the threshold to obtain a partial discharge detection result.

[0059] In other embodiments, the host computer generates a partial discharge spectrum according to the first current data, and the reusable performance test report includes the partial discharge spectrum.

[0060] S230 , increasing the voltage of the high-voltage cable to be tested to a preset target voltage and maintaining the voltage test for a preset duration, and collecting second current data and voltage data of the high-voltage cable to be tested.

[0061] The target voltage represents the test voltage of the withstand voltage test. The second current data is the current data collected during the withstand voltage test.

[0062] In actual application, the target voltage and duration of the withstand voltage test are set in advance according to the test requirements. For example, the target voltage is set to 2.5U0 and the withstand voltage test duration is 30 minutes. In specific implementation, the voltage of the high-voltage cable to be tested is gradually increased to 2.5U0 by the variable frequency series resonant AC withstand voltage device and maintained for 30 minutes, and the voltage data and second current data of the high-voltage cable to be tested are recorded. In other embodiments, before the withstand voltage test, a leakage current limit is set. During the process of increasing the voltage to the target voltage and maintaining the withstand voltage test duration, the leakage current is recorded. When the leakage current exceeds the limit, the test is stopped immediately and the voltage is slowly reduced to zero.

[0063] S240, detecting whether the high-voltage cable to be tested has flashover or breakdown based on the voltage data and the second current data, and obtaining a withstand voltage test result. The electrical performance test result includes a partial discharge detection result and a withstand voltage test result.

[0064] The withstand voltage test results may include whether the tested high-voltage cable has flashover or breakdown, as well as voltage data and second current data. Flashover refers to the discharge phenomenon that occurs on the insulation surface of the high-voltage cable.

[0065] In practical applications, the condition for determining whether a breakdown has occurred may be to analyze the current change trend and amplitude of the second current data. If the current change amplitude is higher than a preset change amplitude threshold, then the high-voltage cable under test is determined to have a breakdown. When a flashover occurs in a high-voltage cable, a sudden voltage drop and a sudden current increase may occur. To determine whether a flashover has occurred, a current limit and a voltage change threshold may be set in advance according to a test standard, and the voltage data and the second current data may be combined to determine whether a flashover has occurred. Specifically, when the current of the high-voltage cable under test is detected to be higher than a preset current limit and the voltage change is higher than a preset voltage change threshold, then the high-voltage cable under test is determined to have a flashover.

[0066] In this embodiment, electrical performance testing of the high-voltage cable to be tested is performed based on partial discharge detection results and a withstand voltage test, which is beneficial for evaluating the insulation performance of the cable, thereby facilitating evaluation of the reusability of the high-voltage cable to be tested based on the insulation performance.

[0067] In an exemplary embodiment, performing a mechanical property test on a high-voltage cable to be tested to obtain a mechanical property test result includes S250 to S280:

[0068] S250, obtaining external appearance data of the high-voltage cable to be tested.

[0069] The external shape data may be three-dimensional data of the outer sheath of the bent section of the high-voltage cable to be tested, or may be obtained by performing binocular stereo imaging of the outer sheath of the bent section of the high-voltage cable to be tested using a three-dimensional visual scanner to collect point cloud data of the outer sheath surface.

[0070] During specific implementation, the external shape data of the high-voltage cable to be tested is collected by a three-dimensional visual scanner, and the external shape data is sent to a host computer.

[0071] S260: Monitor the internal strain distribution of the high-voltage cable to be tested and obtain internal strain data.

[0072] Internal strain data can be obtained by using strain sensors to collect strain on the conductor and insulation layer of the high-voltage cable under test. The principle by which strain sensors detect stress distribution within cables is primarily based on the relationship between the mechanical and electrical properties of materials. When a cable is subjected to external forces, stress or strain is generated within it, causing changes in electrical parameters such as resistance, capacitance, and inductance. By measuring changes in these electrical parameters, strain sensors can indirectly infer the stress or strain values within the cable.

[0073] In specific implementation, the distributed strain sensor is arranged along the axial direction of the high-voltage cable to be tested, the strain distribution of the internal conductor and insulation layer of the high-voltage cable to be tested is monitored, the internal strain data is obtained, and the internal strain data is sent to the host computer.

[0074] S270: Detect whether the change in the internal strain data exceeds a preset strain mutation threshold, and obtain an internal strain detection result.

[0075] The internal strain detection result may include whether the change in the internal strain data exceeds a preset strain mutation threshold.

[0076] In practical applications, a strain mutation threshold is pre-set based on test requirements to detect whether a strain mutation has occurred in the high-voltage cable under test. Specifically, a host computer can analyze changes in internal strain data, determine the amount of change, and compare this change with a preset strain mutation threshold. If the threshold is exceeded, the high-voltage cable under test is considered to have experienced an internal strain mutation.

[0077] S280, performing three-dimensional modeling on the high-voltage cable to be tested based on the external morphology data to obtain a three-dimensional model of the high-voltage cable to be tested, detecting whether there are defects on the outside of the high-voltage cable to be tested based on the three-dimensional model, and obtaining an external defect detection result. The mechanical property test result includes an internal strain detection result and an external defect detection result.

[0078] The external defect detection result may include whether there are defects on the exterior of the high-voltage cable to be tested. The defects may be deformation, cracks, etc. of the outer sheath.

[0079] In practical applications, a standard, defect-free model of the cable sheath can be created in advance based on the model and specifications of the high-voltage cable to be tested as a reference. The resulting 3D model is then compared with the model to determine if there are any differences. The difference between the two models is then used to determine the deformation.

[0080] In this embodiment, by monitoring the internal strain data and external morphology data of the high-voltage cable, it is comprehensively detected whether the mechanical properties of the high-voltage cable to be tested have changed, thereby improving the accuracy of the reusable performance test.

[0081] In one embodiment, after obtaining the electrical performance test results and the mechanical performance test results, and before determining whether the high-voltage cable to be tested has failed based on the electrical performance test results and the mechanical performance test results, the method further includes:

[0082] After each N bending tests are completed, the high-voltage cable to be tested is subjected to a thermal cycle test and a bending test alternately according to a preset number of alternations to obtain a thermal cycle bending test result, wherein N is a positive integer and N is greater than M.

[0083] Thermal cycling testing simulates the temperature fluctuations experienced by cables during actual use, helping to evaluate their performance under these temperature variations. Thermal cycling bending test results can include parameters such as the conductor current during the final two hours of the heating cycle. The heating cycle can be set according to standard test requirements for power cables.

[0084] In one exemplary embodiment, a thermal cycle test can involve applying current to the high-voltage cable under test via a transformer and recording parameters such as the conductor current during the last two hours of the heating cycle. In practice, the current applied to the high-voltage cable under test can be adjusted to cause the cable to undergo a heating cycle, then maintain a high temperature, then cool down, and finally maintain a low temperature, completing a single thermal cycle test.

[0085] In one exemplary embodiment, the thermal cycle test can be performed by applying current to the high-voltage cable to be tested by an electrical performance testing device (module), causing the cable to undergo a process of heating, maintaining high temperature, cooling, and maintaining low temperature, and recording parameters such as the conductor current within the last 2 hours of the heating cycle to complete a single thermal cycle test.

[0086] In one exemplary embodiment, the operator sets the execution timing of the alternating thermal cycle test and the bending test through the host computer. For example, if N is set to 10, the thermal cycle-bending alternating test is performed on the high-voltage cable to be tested every time 10 bending tests are completed: after a single thermal cycle test, a single bending test is performed on the high-voltage cable to be tested again.

[0087] Generate reusable performance test reports, including:

[0088] Integrate electrical performance test results, mechanical performance test results, and thermal cycle bending test results to generate reusable performance test reports.

[0089] In actual applications, the host computer collects electrical performance test results, mechanical performance test results and thermal cycle bending test results, automatically compares the electrical performance test results, mechanical performance test results and thermal cycle bending test results before and after the bending test, determines the data inflection point and marks it, and generates a reusable performance test report. Among them, the data inflection point can be determined by the data that changes significantly before and after the bending test. It can be determined by the differential method, peak detection and other methods for the data collected before and after the bending test. The data in the electrical performance test results, mechanical performance test results and thermal cycle bending test results collected before and after the bending test are visualized, a visualization file is generated, and the data inflection point is marked in the visualization file. For example, for the capacitance data in the electrical performance test results, a capacitance curve is generated by the drawing function library, the data inflection point is determined by the differential method, and the data inflection point is marked in the visualized capacitance curve file.

[0090] In this embodiment, after every N bending tests, the high-voltage cable to be tested is subjected to thermal cycle tests and bending tests alternately to simulate the temperature fluctuations of the cable throughout the year or during the start-up and shutdown of the equipment, which is beneficial to improving the reliability of the reusable performance test.

[0091] In an exemplary embodiment, a thermal cycle test and a bending test are alternately performed on a high-voltage cable to obtain a thermal cycle bending test result, including:

[0092] The high-voltage cable to be tested is energized and heated to a preset first thermal cycle test temperature, and maintained for a preset thermal cycle test time.

[0093] During the process in which the temperature of the heated high-voltage cable to be tested drops to a preset second thermal cycle test temperature, conductor current data of the high-voltage cable to be tested is obtained.

[0094] When the temperature of the high-voltage cable to be tested drops to a preset second thermal cycle test temperature, a bending test is performed on the high-voltage cable to be tested, and the thermal cycle bending test result includes conductor current data.

[0095] The first thermal cycle test temperature is higher than the second thermal cycle test temperature, and the first thermal cycle test temperature, the thermal cycle test time, and the second thermal cycle test temperature are parameters of the thermal cycle test.

[0096] In actual applications, the first thermal cycle test temperature, thermal cycle test time and second thermal cycle test temperature are set in advance according to the test requirements. The high-voltage cable to be tested is securely connected to the thermal cycle test equipment (such as a power supply), and the first thermal cycle test temperature is set to 90 degrees, the thermal cycle test time is 8 hours, and the second thermal cycle test temperature is 30 degrees. In other embodiments, the electrical performance test device (module) can also perform a thermal cycle test on the high-voltage cable to be tested. Specifically, the electrical performance test device (module) is controlled by the host computer to raise the high-voltage cable to be tested to a preset thermal cycle test voltage (such as set to 2U0 voltage) and power on for heating to ensure that the test conditions are consistent with the actual power-on state. Use a temperature sensor to monitor the cable conductor temperature and heat the cable until it reaches 90 degrees. In the process of heating the conductor temperature of the high-voltage cable to be tested to 90 degrees, the conductor current data of the high-voltage cable to be tested can be obtained by the current sensor of the electrical performance test module.

[0097] After the cable reaches 90°C and maintains heating for 8 hours, the heating is stopped and the cable is allowed to cool naturally to 30°C. A bending test is performed on the high-voltage cable to verify the cable's flexibility and bending resistance in a fluctuating temperature environment. The bending test here refers to the steps in the above-mentioned embodiment of the bending test for the high-voltage cable under test and will not be repeated here.

[0098] In this embodiment, by alternately performing thermal cycle tests and bending tests on the high-voltage cable to be tested, it is beneficial to specifically evaluate the electrical and mechanical properties of the cable in actual application scenarios, thereby improving the accuracy of reusable performance evaluation.

[0099] In an exemplary embodiment, judging whether the high-voltage cable to be tested is failed according to the electrical performance test results and the mechanical performance test results includes:

[0100] When the partial discharge detection result indicates that the partial discharge amount of the high-voltage cable under test exceeds a preset partial discharge amount threshold, or the withstand voltage test result indicates that the high-voltage cable under test has flashover or breakdown, it is determined that the high-voltage cable under test has failed.

[0101] When the internal strain detection result indicates that the high-voltage cable under test has a sudden strain change, or the external defect detection result indicates that the high-voltage cable under test has an external defect, it is determined that the high-voltage cable under test has failed.

[0102] In practical applications, when determining whether a high-voltage cable under test has failed based on the electrical performance test results, the high-voltage cable under test is determined to have failed if at least one of the following two conditions is met: (1) The host computer detects that the partial discharge amount of the high-voltage cable under test exceeds a preset partial discharge amount threshold based on the partial discharge detection results, and determines that the high-voltage cable under test has partial discharge. (2) The host computer detects that the high-voltage cable under test has flashover or breakdown based on the withstand voltage test results.

[0103] Regarding the determination of cable failure based on the mechanical properties test results, the cable is determined to be failed if at least one of the following two conditions is met: (1) the change in the internal strain data in the internal strain detection results exceeds the preset strain mutation threshold. (2) the external defect detection results indicate that there are defects on the exterior of the high-voltage cable under test, and the high-voltage cable under test is determined to be failed.

[0104] In this embodiment, the cable failure judgment conditions based on electrical and mechanical multi-dimensional factors are conducive to accurately evaluating the status of the high-voltage cable.

[0105] In order to make a clearer description of the high-voltage cable reusability performance test method provided by this application, the following is a specific embodiment and the attached Figure 3 To illustrate, this specific embodiment includes the following steps:

[0106] Perform pre-test calibration on the high voltage cable to be tested.

[0107] S1, perform bending test on the high voltage cable to be tested.

[0108] S2, performing electrical performance test and mechanical performance test on the high-voltage cable to be tested respectively after completing M bending tests, to obtain electrical performance test results and mechanical performance test results, wherein M is a positive integer.

[0109] Specifically, electrical performance tests and mechanical performance tests are performed on the high-voltage cable to be tested, and the electrical performance test results and mechanical performance test results are obtained, including:

[0110] S2-1, raising the voltage of the high-voltage cable to be tested to a preset partial discharge detection voltage, maintaining the preset partial discharge detection time, and collecting first current data of the high-voltage cable to be tested.

[0111] S2-2: Detect, based on the first current data, whether there is partial discharge in the high-voltage cable to be tested and whether the amount of partial discharge exceeds a preset partial discharge amount threshold, and obtain a partial discharge detection result.

[0112] S2-3, increasing the voltage of the high-voltage cable to be tested to a preset target voltage and maintaining the preset withstand voltage test time, and collecting second current data and voltage data of the high-voltage cable to be tested.

[0113] S2-4, based on the voltage data and the second current data, detect whether the high-voltage cable to be tested has flashover or breakdown, and obtain the withstand voltage test result. The electrical performance test result includes the partial discharge detection result and the withstand voltage test result.

[0114] S2-5, obtaining external morphology data of the high-voltage cable to be tested.

[0115] S2-6, monitoring the internal strain distribution of the high-voltage cable to be tested and obtaining internal strain data.

[0116] S2-7, detecting whether the change in the internal strain data exceeds a preset strain mutation threshold, and obtaining an internal strain detection result.

[0117] S2-8, three-dimensional modeling of the high-voltage cable to be tested is performed based on the external morphology data to obtain a three-dimensional model of the high-voltage cable to be tested, and whether there are defects on the outside of the high-voltage cable to be tested is detected based on the three-dimensional model to obtain external defect detection results. The mechanical property test results include internal strain detection results and external defect detection results.

[0118] S3, after each N bending tests are completed, performing a thermal cycle test and a bending test alternately on the high-voltage cable to be tested according to a preset number of alternations to obtain a thermal cycle bending test result, wherein N is a positive integer and N is greater than M.

[0119] Specifically, a thermal cycle test and a bending test are alternately performed on the high-voltage cable to obtain thermal cycle bending test results, including:

[0120] S3-1, heating the high-voltage cable to be tested to a preset first thermal cycle test temperature and maintaining the temperature for a preset thermal cycle test time.

[0121] S3-2, when the temperature of the high-voltage cable to be tested drops to a preset second thermal cycle test temperature after being heated, obtaining conductor current data of the high-voltage cable to be tested.

[0122] S3-3, when the temperature of the high-voltage cable to be tested drops to a preset second thermal cycle test temperature, performing a bending test on the high-voltage cable to be tested.

[0123] S3-4, Thermal Cycling Bend Test Results including Conductor Current Data.

[0124] S4, judging whether the high-voltage cable to be tested is faulty based on the electrical performance test results and the mechanical performance test results.

[0125] Specifically, when the partial discharge detection result indicates that the partial discharge amount of the high-voltage cable under test exceeds a preset partial discharge amount threshold, or the withstand voltage test result indicates that the high-voltage cable under test has flashover or breakdown, it is determined that the high-voltage cable under test has failed.

[0126] When the internal strain detection result indicates that the high-voltage cable under test has a sudden strain change, or the external defect detection result indicates that the high-voltage cable under test has an external defect, it is determined that the high-voltage cable under test has failed.

[0127] S5, when the high-voltage cable to be tested has not failed, return to step S1, and stop the test until the number of bending tests reaches a preset number of tests or the high-voltage cable to be tested fails.

[0128] S6, integrates the electrical performance test results, mechanical performance test results and thermal cycle bending test results to generate a reusable performance test report.

[0129] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0130] Based on the same inventive concept, in an exemplary embodiment, Figure 4 As shown, a high-voltage cable reusable performance testing device is provided, including a master control module 120, and a bending control module 140, an electrical performance testing module 160, and a mechanical performance testing module 180 respectively connected to the master control module 120:

[0131] The bending control module 140 is used to perform a bending test on the high-voltage cable to be tested.

[0132] The electrical performance test module 160 is used to perform electrical performance testing on the high-voltage cable to be tested;

[0133] The mechanical properties testing module 180 is used to perform mechanical properties testing on the high-voltage cable to be tested.

[0134] The master control module 120 is used to control the bending control module 140, the electrical performance test module 160 and the mechanical performance test module 180 to perform a bending test on the high-voltage cable to be tested based on any of the above-mentioned high-voltage cable reusability performance test method embodiments to obtain a reusability performance test result.

[0135] In actual use, the operator pre-sets the timing for testing the high-voltage cable under test in the bending control module, electrical performance test module, and mechanical performance test module through the master control module. Parameters are also pre-set for each module based on the test content. For example, for the bending test module, the bending radius, bending speed, and number of test cycles (test cycles) are set. The bending speed is determined based on actual operating conditions, for example, it can be adjusted between 0.1 and 2.0 m / s (meters per second). The bending radius can range from 9D to 25D (D is the outer diameter of the high-voltage cable under test). The number of tests can be determined empirically. For example, the bending radius is set to 12D (default value), the bending speed is set to 0.5 m / s, and the number of cycles is set to 30. For the electrical and mechanical performance tests, execution is set to occur after M = 5 bending tests have been completed. The conditions for evaluating the electrical performance of the high-voltage cable under test are set based on the electrical performance test content, and the conditions for evaluating the mechanical performance of the high-voltage cable under test are set based on the mechanical performance test content.

[0136] During specific implementation, the main control module sends a control instruction to the bending test module, and the bending control module responds to the control instruction of the main control module, and the bending test device performs a bending test on the high-voltage cable to be tested. After completing 5 bending tests, the electrical performance test module and the mechanical performance test module are controlled to perform electrical performance tests and mechanical performance tests on the high-voltage cable to be tested, respectively, to obtain electrical performance test results and mechanical performance test results. The main control module determines whether the high-voltage cable to be tested has failed based on the electrical performance test results and the mechanical performance test results. In the case that the high-voltage cable to be tested has not failed, the control returns to the step of performing a bending test on the high-voltage cable to be tested by controlling the bending test module until the number of bending tests reaches the preset number of tests or the high-voltage cable to be tested fails, and the test is stopped. In this embodiment, the specific implementation method of the main control module, the bending control module, the electrical performance test module and the mechanical performance test module to perform the reusable performance test of the high-voltage cable to be tested refers to the steps in the above-mentioned embodiment of the high-voltage cable reusable performance test method, and will not be repeated here.

[0137] In this embodiment, considering the significant differences in the reusable performance of reusable temporarily short-circuited high-voltage cables under different operating conditions, a reusable performance testing device with a modular integrated design is proposed, including a bending control module, an electrical performance testing module, and a mechanical performance testing module, which are respectively used to perform bending tests, electrical performance tests, and mechanical performance tests on high-voltage cables, thereby reducing the time cost associated with test switching. The master control module controls the bending control module, electrical performance testing module, and mechanical performance testing module to collaboratively perform automated, multi-dimensional performance testing, thereby improving the accuracy and test efficiency of the reusable performance test results of the high-voltage cable.

[0138] In other embodiments, the bending control module 140 is further configured to perform a thermal cycle test on the high-voltage cable under test. In practical applications, an alternating sequence, a preset number of alternations, and an execution timing are set for the alternating thermal cycle test and bending test. For example, the execution timing is set to be every N = 10 bending tests, and the preset number of alternations is 20. After every 10 bending tests, the master control module 120 controls the electrical performance test module and the bending test module to perform the thermal cycle test and bending test alternately according to the preset number of alternations, thereby obtaining the thermal cycle bending test results.

[0139] In an exemplary embodiment, the high-voltage cable to be tested is wound on a take-up drum, the device further includes a stretching platform, and the bending control module 140 includes a winding machine, a winding wheel and a test motor connected to each other:

[0140] The test motor is used to control the rotation of the crimping wheel so that the crimping wheel bends the high-voltage cable to be tested;

[0141] The winding machine is used to pull the high-voltage cable to be tested from the winding wheel to the stretching platform for unwinding.

[0142] In practical applications, the specific structure of the high-voltage cable reusable performance test device is as follows: Figure 5 As shown, it includes: a winding machine 1, a dynamic load unit 2, an electrical control cabinet 3, a guide wheel 4, an extension platform 5, a strain sensor 6, a test motor 7, a winding wheel 8, a master control module 9, a 3D scanner 10, an adaptive fixture 11, a take-up reel 12, a multi-axis robotic arm 13, an electrical performance test module 14, a servo motor 15, and a torque sensor 16.

[0143] In an exemplary embodiment, the mechanical properties testing module also includes a high-precision torque / tension sensor 16 (accuracy ±0.1% FS) for measuring torque and axial tension during bending. The torque and axial tension data are transmitted to the master control module. Based on the torque, axial tension, and internal strain data, the master control module analyzes stress changes in the tested high-voltage cable at different bending levels, generates stress analysis results, and uses these stress analysis results to assess the reusability of the tested high-voltage cable.

[0144] In this embodiment, the bending control module includes a winding machine 1, a winding wheel 8 and a test motor 7 connected to each other. The bending control module also includes a multi-axis robot arm 13 and an adaptive clamp 11.

[0145] Among them, the multi-axis robotic arm 13 is driven by a servo motor 15, the dynamic load unit 2 is programmed to control the winding machine 1 to adjust the bending radius within the range of 9D to 25D (D is the outer diameter of the cable), the bending speed is adjusted between 0.1-2.0m / s according to actual working conditions, and the winding wheel 8 is driven by a test motor 7.

[0146] The adaptive fixture 11 is equipped with a pressure feedback device to ensure that the cable does not undergo axial displacement or torsion during the test.

[0147] Among them, the dynamic load unit 2 has a built-in PID control algorithm, which can apply a dynamic tensile force of 0-50kN to simulate the tension changes during cable laying, and automatically record the number of cycles to ensure that the number of test cycles is ≥30 times.

[0148] In practice, before the bending test, the high-voltage cable to be tested is wound onto a take-up reel according to the cable model. This reel is then mounted on a take-up frame using a multi-axis robotic arm and clamped with an adaptive clamp. The cable is then unwound and pulled onto the extension platform using a traction rope and cable connector, and then secured with a cable reel selected according to the cable model.

[0149] In a specific implementation, the bending test device responds to:

[0150] The cable bending test motor M (7) can rotate forward and reverse. When the cable bending test motor rotates forward, the cable winding wheel rotates forward; when the cable bending test motor rotates reversely, the cable winding wheel rotates reversely. The linear speed of the cable bending test motor M (7) in forward / reverse operation is synchronized with the linear speed of the traction winding machine 1 in forward / reverse operation. This allows the high-voltage cable to be tested to perform a reciprocating cycle of winding and unwinding on the winding wheel and the stretching platform.

[0151] In one exemplary embodiment, the bending test can be performed using a bending test device, such as a cable bending tester. Specifically, the operator pre-sets the bending test parameters of the bending test device on the master control module, including the bending radius. The bending radius can be adjusted according to the test requirements. For example, the bending range is set within the range of 9D to 25D (D is the outer diameter of the cable) according to the standard test requirements for power cables (such as the GB / T 11017.1 standard). Before the bending test, the cable is pre-installed on the fixture of the testing machine, and both ends of the cable are fixed. During the bending test, the drive motor of the cable bending tester is started to drive the bending mechanism to apply bending stress to the cable according to the set bending test parameters to perform the bending test.

[0152] In this embodiment, the bending test module is used to cyclically bend and unfold the cable to be tested, simulating the natural bending of the cable during laying and the dynamic bending during equipment movement, thereby improving the effectiveness of the bending test.

[0153] In an exemplary embodiment, the high-voltage cable reusability performance testing device also includes a limit travel switch arranged on the extension platform, which is used to control the test motor to change the bending direction of the high-voltage cable to be tested when the connector of the high-voltage cable to be tested contacts the limit travel switch.

[0154] Among them, the limit travel switch is a safety device used to control the range of motion of mechanical equipment. Figure 5 As shown, a limit travel switch (not numbered in the figure) is provided on the extension platform 5 for detecting whether the cable connector of the high-voltage cable to be tested has reached a preset position. When the cable connector reaches the preset position, the limit travel switch is triggered, and a signal is sent to the control system of the test motor to cause the motor to reversely bend the high-voltage cable to be tested, thereby realizing a cyclic bending test.

[0155] In practice, a limit switch can be pre-installed at each end of the extension platform, allowing it to be triggered during both the forward and reverse bending tests. When the cable connector reaches either end of the extension platform, the limit switch is triggered, sending a signal to the test motor control system to cause the motor to bend the high-voltage cable in the reverse direction, completing the cyclic bending test.

[0156] In an exemplary embodiment, the electrical performance test module 160 includes a partial discharge detection submodule and a voltage withstand test submodule respectively connected to the main control module 120:

[0157] The partial discharge detection submodule is used to collect first current data of the high-voltage cable to be tested and send the first current data to the main control module 120 when the voltage test submodule increases the voltage of the high-voltage cable to be tested to a preset partial discharge detection voltage and maintains the preset partial discharge detection time.

[0158] Among them, the partial discharge detection submodule includes a high-frequency current sensor (frequency response range 10kHz-30MHz (Hertz)) and a partial discharge signal acquisition unit, with a sensitivity of ≤5pC and a sampling rate of ≥100MS / s.

[0159] In actual applications, the partial discharge detection voltage and duration are pre-set based on test requirements. For example, the voltage of the high-voltage cable under test can be gradually increased to 1.75U0 (U0 is the rated voltage of the cable) using a withstand voltage test device and maintained for 10 seconds, then slowly decreased to 1.5U0. During this process, the high-frequency current sensor collects the first current data of the high-voltage cable under test and sends the collected first current data to the partial discharge signal acquisition unit. The partial discharge signal acquisition unit amplifies, filters, and digitizes the received sensor data to ensure signal accuracy and reliability, and then sends the processed first current data to the master control module.

[0160] Based on the first current data, the master control module determines whether the current of the high-voltage cable under test exceeds a preset current threshold, which is set according to the test standard. If the current exceeds the preset current threshold, partial discharge is determined to exist in the high-voltage cable under test. The amount of partial discharge is determined based on the first current data, and a partial discharge map is generated based on the first current data. In one exemplary embodiment, the amount of partial discharge can be determined based on the first current data by measuring the amount of partial discharge using a partial discharge tester. The partial discharge threshold is set to 5 pC (picocoulomb). The measured partial discharge amount is compared with the threshold to obtain a partial discharge detection result.

[0161] The withstand voltage test submodule is used to increase the voltage of the high-voltage cable to be tested to a preset target voltage and maintain a preset withstand voltage test duration, collect the second current data and voltage data of the high-voltage cable to be tested, and send the second current data and voltage data to the main control module 120.

[0162] Among them, the voltage withstand test submodule is a variable frequency series resonant AC voltage withstand device, which consists of a frequency conversion control unit, an excitation transformer, a reactor and a capacitive voltage divider. The output voltage range is 0-1000kV with an accuracy of ±1%.

[0163] In actual applications, the target voltage, frequency, and withstand voltage test duration are set in advance through the master control module. For example, the target voltage is set to 2.5U0 and the withstand voltage test duration is 30 minutes. In specific implementation, the voltage of the high-voltage cable to be tested is gradually increased to 2.5U0 through the variable frequency series resonant AC withstand voltage device and maintained for 30 minutes, the voltage data and the second current data of the high-voltage cable to be tested are recorded, and the recorded data are sent to the master control module. In other embodiments, before the withstand voltage test, a leakage current limit is set, and the leakage current is recorded in the process of rising to the target voltage and maintaining the withstand voltage test duration. When the leakage current exceeds the limit, the test is stopped immediately and the voltage is slowly reduced to zero.

[0164] The master control module analyzes the current change trend and amplitude of the second current data. If the current change amplitude exceeds a preset change amplitude threshold, it is determined that the high-voltage cable under test has a breakdown. To determine whether a flashover has occurred, the current limit and voltage change threshold can be pre-set according to the test standard. When a flashover occurs, a sudden voltage drop and a sudden current increase may occur. The determination of whether a flashover has occurred can be based on the voltage data and the second current data. If the current of the high-voltage cable under test is higher than the preset current limit and the voltage change is higher than the preset voltage change threshold, the high-voltage cable under test is determined to have a flashover. A withstand voltage curve is generated based on the voltage data and the second current data.

[0165] In an exemplary embodiment, the mechanical properties testing module 180 includes a strain sensor and a visual scanning unit respectively connected to the master control module 120:

[0166] The strain sensor is used to monitor the internal strain distribution of the high-voltage cable to be tested, obtain internal strain data, and send the internal strain data to the master control module 120 .

[0167] The visual scanning unit is used to collect external appearance data of the high-voltage cable to be tested and send the external appearance data to the master control module 120.

[0168] Among them, strain sensors (spatial resolution ≤ 1 cm) are arranged along the cable axis to monitor the strain distribution of the internal conductor and insulation layer, so as to detect whether the strain mutation threshold is ≥ 0.5%.

[0169] Among them, the 3D visual scanner 10 (binocular stereo imaging, accuracy ≤ 0.1mm) performs three-dimensional modeling of the outer sheath of the cable bending section, identifies deformation or crack defects through point cloud analysis, and provides real-time feedback to the master control module 9.

[0170] During specific implementation, a 3D visual scanner collects external morphology data of the high-voltage cable to be tested and sends the external morphology data to the master control module. The strain sensor collects the strain of the internal conductor and insulation layer of the high-voltage cable to be tested to obtain internal strain data, and sends the internal strain data to the master control module. The master control module determines the change in the internal strain data based on the change in the internal strain data, and compares the change with the preset strain mutation threshold of 0.5%. If the preset strain mutation threshold is exceeded, it is determined that the high-voltage cable to be tested has an internal strain mutation. A standard, defect-free standard model of the cable outer sheath is established in advance based on the model and specifications of the high-voltage cable to be tested as a reference. The three-dimensional model obtained by modeling based on the external morphology data is compared with it, and whether there is a defect is determined based on whether there is a difference. The difference between the two is calculated to determine the deformation amount.

[0171] In one embodiment, the master control module automatically identifies performance inflection points (e.g., the number of tests at which cracks first appeared) based on the integrated electrical withstand voltage curve, partial discharge map, strain distribution cloud diagram, and sheath deformation 3D model, and generates a PDF test report. If the high-voltage cable under test does not fail after reaching the preset number of tests, it is determined to meet the reusability performance requirements and the test report is marked as "passed."

[0172] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0173] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for testing the reusability of a high-voltage cable, characterized in that: The method comprises: Perform bending test on the high voltage cable to be tested; After each M bending test is completed, an electrical performance test and a mechanical performance test are performed on the high-voltage cable to obtain an electrical performance test result and a mechanical performance test result, wherein M is a positive integer; Determining whether the high-voltage cable to be tested is faulty based on the electrical performance test results and the mechanical performance test results; If the high-voltage cable to be tested has not failed, returning to the step of performing a bending test on the high-voltage cable to be tested, and stopping the test until the number of bending tests reaches a preset number of times or the high-voltage cable to be tested fails; The electrical performance test results and the mechanical performance test results are integrated to generate a reusable performance test report.

2. The method according to claim 1, characterized in that Performing an electrical performance test on the high-voltage cable to be tested to obtain an electrical performance test result, including: Increasing the voltage of the high-voltage cable to be tested to a preset partial discharge detection voltage, maintaining a preset partial discharge detection time, and collecting first current data of the high-voltage cable to be tested; Detecting, based on the first current data, whether partial discharge occurs in the high-voltage cable to be tested and whether the amount of partial discharge exceeds a preset partial discharge amount threshold, thereby obtaining a partial discharge detection result; Increasing the voltage of the high-voltage cable to be tested to the preset target voltage and maintaining the preset withstand voltage test time, and collecting second current data and voltage data of the high-voltage cable to be tested; Detecting whether the high-voltage cable to be tested has flashover or breakdown based on the voltage data and the second current data, and obtaining a withstand voltage test result; The electrical performance test results include the partial discharge test results and the voltage withstand test results.

3. The method according to claim 2, characterized in that Performing a mechanical property test on the high-voltage cable to be tested to obtain mechanical property test results includes: Acquiring external appearance data of the high-voltage cable to be tested; Monitoring the internal strain distribution of the high-voltage cable to be tested to obtain internal strain data; Detecting whether a change in the internal strain data exceeds a preset strain mutation threshold, and obtaining an internal strain detection result; Performing three-dimensional modeling on the high-voltage cable to be tested according to the external morphology data to obtain a three-dimensional model of the high-voltage cable to be tested, and detecting whether there are defects on the exterior of the high-voltage cable to be tested according to the three-dimensional model to obtain an external defect detection result; The mechanical property test results include the internal strain detection results and the external defect detection results.

4. The method according to claim 1, wherein After obtaining the electrical performance test results and the mechanical performance test results, and before determining whether the high-voltage cable to be tested has failed based on the electrical performance test results and the mechanical performance test results, the method further includes: After each N bending tests are completed, performing a thermal cycle test and a bending test on the high-voltage cable to be tested alternately according to a preset number of alternations to obtain a thermal cycle bending test result, wherein N is a positive integer and N is greater than M; The generating of the reusable performance test report further includes: The electrical performance test results, the mechanical performance test results, and the thermal cycle bending test results are integrated to generate a reusable performance test report.

5. The method according to claim 4, characterized in that The step of alternately performing a thermal cycle test and a bending test on the high-voltage cable to be tested to obtain a thermal cycle bending test result includes: The high-voltage cable to be tested is energized and heated to a preset first thermal cycle test temperature, and maintained for a preset thermal cycle test time; When the temperature of the heated high-voltage cable to be tested drops to a preset second thermal cycle test temperature, obtaining conductor current data of the high-voltage cable to be tested; When the temperature of the high-voltage cable to be tested drops to the preset second thermal cycle test temperature, performing a bending test on the high-voltage cable to be tested; The thermal cycle bending test results include the conductor current data.

6. The method according to claim 3, characterized in that The determining whether the high-voltage cable to be tested is failed according to the electrical performance test result and the mechanical performance test result includes: When the partial discharge detection result indicates that the partial discharge amount of the high-voltage cable to be tested exceeds the preset partial discharge amount threshold, or the withstand voltage test result indicates that the high-voltage cable to be tested has flashover or breakdown, determining that the high-voltage cable to be tested has failed; When the internal strain detection result indicates that the high-voltage cable to be tested has a sudden strain change, or the external defect detection result indicates that there is a defect on the exterior of the high-voltage cable to be tested, it is determined that the high-voltage cable to be tested has failed.

7. A high voltage cable reusability performance test device, characterized in that: The device includes a master control module, and a bending control module, an electrical performance test module, and a mechanical performance test module respectively connected to the master control module for communication; The bending control module is used to perform a bending test on the high-voltage cable to be tested; The electrical performance test module is used to perform an electrical performance test on the high-voltage cable to be tested; The mechanical properties testing module is used to perform a mechanical properties test on the high-voltage cable to be tested; The master control module is used to control the bending control module, the electrical performance test module and the mechanical performance test module to perform a reusable performance test on the high-voltage cable to be tested based on the high-voltage cable reusability performance test method as described in any one of claims 1 to 6, and obtain a reusable performance test result.

8. The device according to claim 7, characterized in that The high-voltage cable to be tested is wound on a take-up drum. The device further includes a stretching platform. The bending control module includes a winding machine, a winding wheel and a test motor connected to each other. The test motor is used to control the rotation of the crimping wheel so that the crimping wheel bends the high-voltage cable to be tested; The winding machine is used to pull the high-voltage cable to be tested from the winding wheel to the stretching platform for unfolding.

9. The device according to claim 8, characterized in that A limit travel switch is provided on the extension platform, and the master control module is used to control the test motor to change the bending direction of the high-voltage cable to be tested when the connector of the high-voltage cable to be tested contacts the limit travel switch.

10. The device according to claim 7, characterized in that The electrical performance test module includes a partial discharge detection submodule and a voltage withstand test submodule respectively connected to the main control module: The partial discharge detection submodule is configured to collect first current data of the high-voltage cable to be tested and send the first current data to the main control module while the voltage withstand test submodule increases the voltage of the high-voltage cable to be tested to a preset partial discharge detection voltage and maintains the voltage for a preset partial discharge detection time. The withstand voltage test submodule is used to increase the voltage of the high-voltage cable to be tested to the preset target voltage and maintain the preset withstand voltage test duration, collect the second current data and voltage data of the high-voltage cable to be tested, and send the second current data and the voltage data to the main control module.

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