Cable aging test device and cable aging test method

Abstract

The invention discloses a cable aging test device and a cable aging test method. The cable aging test device comprises a test box, a tensile loading module, a bending loading module, a voltage output module, a salinity adjusting module and a temperature adjusting module. A containing cavity is formed in the test box, cable interfaces are formed in the two opposite box walls of the test box, the two cable interfaces are communicated with the containing cavity, the center lines of the two cable interfaces are coaxial, the two cable interfaces are used for being connected with a cable in a sealed mode so that the cable can be erected in the containing cavity, and the containing cavity is further used for being filled with simulated seawater to soak the cable. The cable testing device can be used for testing the performance of the cable under the coupling effect of different physical fields, and a high-fidelity and high-efficiency testing platform is provided for reliability evaluation of the high-voltage submarine cable.

Description

Technical Field

[0001] The present invention relates to the field of cable detection, and in particular to a cable testing device and a cable aging testing method. Background Art

[0002] Submarine cables are exposed to high voltage, high temperature, and alternating mechanical forces over long periods of time, which can easily cause the cable's insulation to age and fail. Therefore, cable aging testing is an important part of cable quality inspection.

[0003] In related technologies, submarine cable insulation aging tests only consider a single field loading mode: mechanical loading, temperature application, and electrical stress application are independent of each other, and cannot simulate the synergistic coupling of mechanical force, temperature, and voltage in actual operation. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one objective of the present invention is to provide a cable testing device capable of testing the performance of cables under the coupling of different physical fields, thereby providing a high-fidelity, high-efficiency testing platform for reliability assessment of high-voltage submarine cables.

[0005] The invention also provides a cable aging testing method.

[0006] The present invention provides a cable aging test device, which includes a test chamber, a tensile loading module, a bending loading module, a voltage output module, a salinity adjustment module, and a temperature adjustment module. The test chamber is provided with a housing chamber, and two opposite walls of the test chamber are provided with cable interfaces. The two cable interfaces are connected to the housing chamber, and the center lines of the two cable interfaces are coaxial. The two cable interfaces are used to seal and connect cables so that the cables are installed in the housing chamber. The housing chamber is also used to fill simulated seawater to soak the cables. The tensile loading module is provided outside the test chamber and is used to apply an axial tensile force parallel to the center line to the cables. The bending loading module is provided inside the housing chamber and includes an arc pressure block driving device and an arc pressure block. The arc pressure block driving device is used to drive the arc pressure block to press against the cable installed in the housing chamber. The voltage output module is provided outside the test chamber and is used to output voltage to the conductor of the cable. The salinity adjustment module is provided inside the housing chamber and is used to inject salt water or deionized water into the housing chamber. The temperature adjustment module is used to adjust the temperature of the simulated seawater in the housing chamber.

[0007] In some embodiments, the bending loading module further includes two cable support structures disposed in the accommodating cavity; the two cable support structures are spaced apart along the center line and are used for laying cables.

[0008] In some embodiments, the cable support structure includes a support column fixedly connected to the bottom of the accommodating cavity and a support wheel rotatably arranged on the top of the support column; a support V-shaped groove is defined on the circumferential surface of the support wheel and is used to apply a supporting force to the cable at least in the opposite direction to the bottom of the accommodating cavity; the arc pressure block driving device is used to drive the arc pressure block to move so that the cable arranged between the two cable support structures is close to or away from the bottom of the accommodating cavity.

[0009] In some embodiments, the bending loading module also includes a bending loading controller and a laser displacement sensor provided at the end of the arc pressure block in the arc extension direction; the laser displacement sensor is used to detect the curvature of the cable; the bending loading controller is communicatively connected to the laser displacement sensor and the arc pressure block driving device, and the bending loading controller is configured to control the arc pressure block driving device to change according to the set displacement or waveform based on the feedback curvature, thereby controlling the curvature of the cable.

[0010] In some embodiments, the tensile loading module includes a tensile drive device and a cable clamping assembly; the number of the cable clamping assemblies is two and they are respectively used to fix the two ends of the connecting cable; the tensile drive device is fixedly connected to at least one of the cable clamping assemblies and drives the cable clamping assembly to move along the center line to apply an axial tensile force parallel to the center line to the cable; wherein, the tensile loading module also includes a tensile loading controller and a high-precision load sensor; the high-precision load sensor is provided between the output end of the tensile drive device and the cable clamping assembly to collect the tensile force, and the tensile loading controller is connected to the high-precision load sensor and the tensile The tensile drive device is communicatively connected to control the driving force of the tensile drive device in a closed loop according to the feedback load force signal of the high-precision load sensor, thereby controlling the tensile force applied to the cable so that the force value changes according to a set value or waveform; and\or, the tensile loading module includes a tensile loading controller and an optical fiber strain sensor; the optical fiber strain sensor is arranged in the accommodating cavity to detect the strain of the cable; the tensile loading controller is communicatively connected to the optical fiber strain sensor and the tensile drive device to control the driving force of the tensile loading drive device in a closed loop according to the feedback strain signal of the optical fiber strain sensor, thereby directly controlling the strain of the cable so that the strain changes according to a set rate or waveform.

[0011] In some embodiments, the loading waveform of the tensile drive device includes a sine wave and a triangular wave; the loading waveform of the arc pressure block drive device includes a sine wave and a square wave; the cable aging test device also includes a phase difference controller; the phase difference controller is communicatively connected to the tensile drive device and the arc pressure block drive device respectively and is used to control the phase difference between the tensile drive device and the arc pressure block drive device to adjust the tensile-bending timing applied to the cable.

[0012] In some embodiments, the temperature regulation module includes a liquid inlet pipe, a liquid outlet pipe, a circulating heat exchange system, a temperature detection device and a PID temperature control module; the circulating heat exchange system is connected to the accommodating chamber through the liquid inlet pipe and the liquid outlet pipe to drive the simulated seawater in the accommodating chamber to circulate and be used to heat or cool the simulated seawater; the circulating heat exchange system and the temperature detection device are respectively communicatively connected to the PID temperature control module; the circulating heat exchange system responds to the control signal of the PID temperature control module and is used to adjust the temperature of the simulated seawater in the accommodating chamber by injecting liquid into the accommodating chamber.

[0013] In some embodiments, the salinity adjustment module includes a pressurized nozzle, a deionized water injection valve, and a stirring paddle installed at the bottom of the accommodating chamber, the pressurized nozzle is used to inject salt water into the accommodating chamber, the deionized water injection valve is used to inject deionized water into the accommodating chamber, and the stirring paddle is used to stir the simulated seawater inside the accommodating chamber.

[0014] In some embodiments, the voltage output module includes a high-frequency voltage generator and a conductor connection assembly; the conductor connection assembly includes a plurality of arc-shaped graphite pressing blocks, which are used to be arranged around the conductor of the cable and clamp the conductor of the cable with a preset pressure; the high-frequency voltage generator outputs voltage to the cable through the plurality of arc-shaped graphite pressing blocks.

[0015] The present invention also provides a cable aging test method, which is applied to the above-mentioned cable aging test device and comprises the following steps:

[0016] S1: Sample installation: After the two ends of the cable are respectively inserted into the cable interface of the test box, the test box is filled with simulated seawater;

[0017] S2: Composite stress loading and environmental control: applying axial tensile force to the cable through the tensile loading module; bending the cable through the bending loading module; outputting voltage to the cable through the voltage output module; controlling the salt concentration and temperature of the simulated seawater in which the cable is immersed through the salinity adjustment module and the temperature adjustment module;

[0018] S3: Process monitoring: Real-time acquisition of cable surface strain distribution through optical fiber strain sensors;

[0019] S4: Test endpoint detection:

[0020] The partial discharge detector disposed in the accommodating cavity records the discharge amount, and when the actual discharge amount of the partial discharge detector detected within a preset detection period reaches a discharge threshold, it is determined that the cable has a defect and the test is terminated;

[0021] Alternatively, the test is terminated when the combined stress is applied for a preset time.

[0022] In combination with the technical solution, it can be seen that the embodiment provided by the present invention has the following advantages: the cable aging test device can make the cable withstand the coupling of multiple physical fields such as mechanical, electrical, and environmental fields in the accommodating cavity at the same time, accelerate the aging process, and thus test its service life and reliability, providing a high-fidelity and high-efficiency testing platform for the reliability evaluation of high-voltage submarine cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 is a cross-sectional view of a cable aging test device according to an embodiment of the present invention;

[0025] Figure 2-Figure 3 is a partially enlarged view of a bending loading module according to an embodiment of the present invention;

[0026] Figure 4-Figure 5 2 is a schematic diagram of the overall structure of a cable aging test device according to an embodiment of the present invention;

[0027] Figure 6 FIG. 1 is a partial enlarged view of a cable clamp and a conductor connection assembly according to an embodiment of the present invention.

[0028] Reference numerals:

[0029] Cable aging test device 100, cable 200, conductor 201;

[0030] Test box 1, accommodating cavity 11, box wall 12, cable interface 13, dynamic sealing structure 14;

[0031] Tensile loading module 2, tensile driving device 21, cable clamping assembly 22, clamping hoop 221, adjustable bidirectional screw rod 222, fixing seat 23;

[0032] Bending loading module 3, arc-shaped pressing block driving device 31, arc-shaped pressing block 32, cable support structure 33, support column 331, support wheel 332, support V-shaped groove 3321, laser displacement sensor 333;

[0033] Voltage output module 4, conductor connection assembly 41, arc-shaped graphite pressing block 411;

[0034] Salinity adjustment module 5, pressurized nozzle 51, deionized water injection valve 52;

[0035] Temperature regulating module 6, liquid inlet pipe 61, liquid outlet pipe 62, circulating heat exchange system 63;

[0036] Central controller 7. DETAILED DESCRIPTION

[0037] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0040] Cable 200: A conductor 201 is formed by twisting or combining multiple conductors 201 (such as copper or aluminum) according to a certain rule. The outer layer of the conductor 201 is wrapped with an insulating material and a protective structure to form a wire assembly with insulation and mechanical protection functions.

[0041] Reference below Figures 1-6 A cable aging test apparatus 100 according to an embodiment of the present invention is described.

[0042] like Figure 1As shown, this embodiment provides a cable aging test device 100, which includes a test box 1, a tensile loading module 2, a bending loading module 3, a voltage output module 4, a salinity adjustment module 5 and a temperature adjustment module 6.

[0043] A accommodating chamber 11 is provided in the test box 1. Cable interfaces 13 are provided on two opposite walls 12 of the test box 1, that is, a cable interface 13 is provided on one of the two opposite walls 12 of the test box 1, and a cable interface 13 is provided on the other of the two opposite walls 12 of the test box 1. One cable interface 13 is connected to the accommodating chamber 11, and the other cable interface 13 is also connected to the accommodating chamber 11. The center lines of one cable interface 13 and the other cable interface 13 are coaxial. One cable interface 13 can seal and connect the cable 200, and the other cable interface 13 can also seal and connect the cable 200. Thus, the two cable interfaces 13 are respectively connected to different positions of the cable 200. By tightening the two ends of the cable 200, the cable 200 can be installed in the accommodating chamber 11. The accommodating chamber 11 can also be filled with simulated seawater to soak the cable 200.

[0044] The two opposing box walls 12 herein refer to two box walls 12 on the test box 1 that are distributed face to face and have a certain interval therebetween.

[0045] The tensile loading module 2 is disposed outside the test box 1 , and the tensile loading module 2 is capable of applying an axial tensile force parallel to the center line to the cable 200 .

[0046] The bending loading module 3 is disposed in the accommodating cavity 11 and includes an arc-shaped pressing block driving device 31 and an arc-shaped pressing block 32 . The arc-shaped pressing block driving device 31 can drive the arc-shaped pressing block 32 to press against the cable 200 mounted in the accommodating cavity 11 .

[0047] It should be further explained that the arc-shaped pressing block 32 is disposed in the accommodating cavity 11 and located between the two box walls 12 , that is, the arc-shaped pressing block 32 is located between the two cable interfaces 13 to form a three-point bending structure.

[0048] The voltage output module 4 is provided outside the test box 1 , and the voltage output module 4 is capable of outputting voltage to the conductor 201 of the cable 200 ;

[0049] The salinity adjustment module 5 is disposed in the accommodating chamber 11 . The salinity adjustment module 5 can inject salt water or deionized water into the accommodating chamber 11 , thereby adjusting the salinity of the simulated seawater in the accommodating chamber 11 and simulating the salinity conditions of different sea areas or environments.

[0050] The temperature adjustment module 6 can adjust the temperature of the simulated seawater in the accommodating chamber 11 .

[0051] Simulated seawater, as used here, refers to an artificial aqueous solution prepared based on the primary chemical components of natural seawater (such as salts and trace elements). Its salinity, ion composition, pH, and other parameters are similar to those of seawater, and is used to simulate the effects of the marine environment on objects. For example, the salinity of simulated seawater can range from 3.4% to 3.6%, which is the total mass of dissolved salts per unit mass of the aqueous solution.

[0052] In a specific application scenario, the cable 200 is passed through one cable interface 13, then through the accommodating chamber 11 and through another cable interface 13. The two cable interfaces 13 are sealed and connected at different positions of the cable 200. The cable 200 is then tightened at both ends to fix its position in the accommodating chamber 11. At this point, the cable 200 is roughly parallel to the centerline of the cable interface 13. Then, the accommodating chamber 11 is filled with simulated seawater, and the test chamber 1 is sealed.

[0053] At this time, a portion of the cable 200 is accommodated in the accommodating chamber 11 and immersed in simulated seawater, and a portion of the cable 200 passes through the accommodating chamber 11 through the cable interface 13. The tensile loading module 2 applies an axial tensile force parallel to the center line to the portion of the cable 200 that passes through the cable interface 13. The bending loading module 3 is arranged in the accommodating chamber 11, and the arc pressure block driving device 31 drives the arc pressure block 32 to press against the portion of the cable 200 located in the accommodating chamber 11 to cause the cable 200 to bend. Therefore, under the action of the tensile loading module 2 and the bending loading module 3, the cable 200 simulates the bending stress that the cable 200 is subjected to during laying or use, and the aging tolerance of the cable 200 is tested together with the tensile force.

[0054] The voltage output module 4 is electrically connected to the portion of the cable 200 located outside the accommodating cavity 11 , thereby energizing the voltage output module 4 and the cable 200 to simulate electrical stress during operation.

[0055] The salinity adjustment module 5 and the temperature adjustment module 6 adjust the temperature and salinity of the simulated seawater respectively to simulate the temperature, salinity and corrosive environment in which the submarine cable 200 is located.

[0056] It can be seen from the technical solution that the embodiments provided by the present invention have the following advantages:

[0057] The cable aging test device 100 enables the cable 200 to simultaneously withstand the coupling effects of multiple physical fields such as mechanical (axial tension and bending), electrical, and environmental (salinity and temperature) in the accommodating chamber 11, accelerating the aging process, thereby testing its service life and reliability, and providing a high-fidelity and high-efficiency testing platform for reliability assessment of high-voltage submarine cables 200.

[0058] like Figure 1As shown, in a specific embodiment, a water inlet is provided on the top of the test box 1, through which simulated seawater is injected into the test box 1, and a sealing cover can be provided to cover the water inlet to seal the test box 1. The test box 1 is a rectangular box body, the box wall 12 of the box body is made of high-strength glass, and the corners of the box body are reinforced with 316 stainless steel columns. The two opposite side walls of the test box 1 in the left and right directions are provided with a cable interface 13, and a dynamic sealing structure 14 is provided at the cable interface 13. The dynamic sealing structure 14 is arranged at the cable interface 13 and the cable 200 to achieve a sealed connection between the cable interface 13 and the cable 200. The dynamic sealing structure 14 includes a multi-stage rubber lubricating sealing ring, and the cable 200 can be displaced relative to the cable interface 13.

[0059] Example 2

[0060] like Figure 1 and Figure 2 As shown, the bending loading module 3 further includes two cable support structures 33. The cable support structures 33 are disposed within the accommodating cavity 11; the two cable support structures 33 are spaced apart along the centerline, with the cable 200 being mounted between the two cable support structures 33. The provision of two cable support structures 33 facilitates support for the cable 200, reducing wear between the cable 200 and the cable interface 13 during mechanical loading.

[0061] like Figure 1-Figure 3 As shown, further, the support structure includes a support column 331 and a support wheel 332. The support column 331 is fixedly connected to the bottom of the accommodating chamber 11, and the support wheel 332 is rotatably arranged on the top of the support column 331. A support V-shaped groove 3321 is provided on the circumferential surface of the support wheel 332, and the support V-shaped groove 3321 is conducive to the automatic positioning of the cable 200. The circumferential surface of the support wheel 332 can apply a supporting force to the cable 200 at least in the direction opposite to the bottom of the accommodating chamber 11. The arc-shaped pressure block driving device 31 is used to drive the arc-shaped pressure block 32 to move. The arc-shaped pressure block 32 causes the cable 200 mounted between the two support structures to approach or move away from the bottom of the accommodating chamber 11, thereby causing the cable 200 to bend within a preset curvature range.

[0062] The preset curvature range here is between 0.5m and 2m, that is, the curvature of the cable 200 can be 0.5m, 0.75m, 1.3m, 1.6m, 1.89m, etc., which are not listed here one by one. The specific curvature parameters can be set according to the needs of the experiment.

[0063] like Figure 3 As shown, further, the bending loading module 3 also includes a laser displacement sensor 333 . The laser displacement sensor 333 is provided at the end of the arc-shaped pressing block 32 in the arc extension direction. The laser displacement sensor 333 is used to detect the curvature of the cable 200 .

[0064] In some embodiments, the bending loading module 3 further includes a bending loading controller, which is communicatively connected to the laser displacement sensor 333 and the arc-shaped pressing block driving device 31. As can be seen from the above embodiments, the laser displacement sensor 333 obtains the curvature of the cable 200 and feeds the curvature back to the bending loading controller. The bending loading controller, based on the feedback of the curvature, controls the output direction and output displacement of the arc-shaped pressing block driving device 31 to control the movement direction and amplitude of the arc-shaped pressing block 32.

[0065] For example, the curved pressure block drive device 31 can employ a hydraulic servo drive, controlling the transmission of hydraulic energy through feedback signals. Mechanical motion is then output via a hydraulic actuator (hydraulic motor). A laser displacement sensor 333 provides real-time feedback on the motion state, forming a closed-loop control system. The curvature radius loading accuracy of the curved pressure block drive device 31 must be ±0.05 m⁻¹, and the curvature control accuracy must be ±1%.

[0066] For example, the bending loading module 3 has two loading modes: a static bending mode and a dynamic bending mode. In the static bending mode, the arc-shaped pressure block driving device 31 presses against the cable 200 via the arc-shaped pressure block 32 and applies a constant load to the cable 200, thereby fixing the cable 200 at a fixed curvature. In the dynamic bending mode, the arc-shaped pressure block driving device 31 presses against the cable 200 via the arc-shaped pressure block 32 and applies a periodically varying load to the cable 200, thereby causing the cable 200 to cyclically deform during bending and recovery. Specifically, in the dynamic bending mode, the bending loading module 3 can apply a sinusoidal wave load (the load amplitude varies sinusoidally over time) or a square wave load (the load amplitude switches instantaneously between maximum and minimum values, forming a rectangular wave) to the cable 200, with a frequency of 0.1-2 Hz.

[0067] For example, the detection accuracy of the laser displacement sensor 333 is ±0.1 mm.

[0068] Example 3

[0069] This embodiment is basically the same as the second embodiment, except that this embodiment provides a specific structure of a tensile loading module 2.

[0070] like Figure 4 As shown, the tensile loading module 2 further includes a tensile drive device 21 and a cable clamping assembly 22. There are two cable clamping assemblies 22, each of which is fixedly connected to the two ends of the cable 200. The tensile drive device 21 is fixedly connected to at least one cable clamping assembly 22, and the tensile drive device 21 drives the cable clamping assembly 22 to move along the centerline to apply an axial tensile force parallel to the centerline to the cable 200.

[0071] like Figure 4As shown, in a specific example, the tensile loading module 2 further includes a fixing base 23. The fixing base 23 and the tensile drive device 21 are symmetrically arranged on either side of the test chamber 1. The fixing base 23 is connected to one end of the cable 200 via a cable clamping assembly 22, and the tensile drive device 21 is connected to the other end of the cable 200 via another cable clamping assembly 22. The cable clamping assembly 22 clamps the armored protective layer of the cable 200 to secure the end of the cable 200. The tensile drive device 21 drives the cable clamping assembly 22 to move along the centerline to apply an axial tensile force parallel to the centerline to the cable 200.

[0072] like Figure 6 As shown, the cable clamp assembly 22 is composed of multiple welded stainless steel clamps embedded with a rubber buffer layer. The mounting opening of the stainless steel clamp is equipped with an adjustable bidirectional screw 222 to adjust the clamping force within a range of 10kN to 50kN. After the cable clamp assembly 22 is connected to the cable 200, it is encapsulated with epoxy resin for protection. This maintains IP68 protection even during dynamic loading.

[0073] For example, the tensile drive device 21 adopts a hydraulic servo device and is equipped with a high-precision encoder, so that its displacement resolution reaches 1 mm. The maximum output force of the hydraulic servo device is 500kN, and the displacement stroke of the hydraulic servo device is ±350mm. The output end of the hydraulic servo device is connected to the cable clamping assembly 22 through a high-strength flange, and the linear motion of the output end is converted into the tension exerted on the cable 200, so that the tensile drive device 21 can evenly transmit the force to the cable 200 during the dynamic loading process. Specifically, the output force resolution is 0.1kN. The hydraulic servo device is provided with an accumulator and a proportional valve, so that the hydraulic servo device can dynamically load the axis tensile force with a sine wave, a triangular wave or a custom waveform. The frequency range of the sine wave, the triangular wave or the custom waveform is 0.1-5Hz, and the dynamic load fluctuation is ≤±1% of the maximum output force.

[0074] Optionally, the tensile loading module 2 further includes a tensile loading controller and a high-precision load sensor. A high-precision load sensor is provided at the output of the hydraulic servo device and the cable clamping assembly 22 to collect tensile force. The tensile loading controller is communicatively connected with the high-precision load sensor and the hydraulic servo device to control the driving force of the hydraulic servo device in a closed-loop manner based on the load force feedback signal from the high-precision load sensor. This directly controls the tensile force applied to the cable 200, causing the force value to vary according to a set value or waveform.

[0075] The force setting range is 1-50kN, that is, the applied tensile force can be changed according to setting values ​​such as 1kN, 2kN, 10kN, 40kN, etc.

[0076] Optionally, the tensile loading module 2 includes a tensile loading controller and a fiber optic strain sensor. The fiber optic strain sensor is disposed in the accommodating cavity 11 to detect strain in the cable 200. The tensile loading controller is in communication with the fiber optic strain sensor and the hydraulic servo device to control the driving force of the hydraulic servo device in a closed-loop manner based on the strain signal feedback from the fiber optic strain sensor. This directly controls the strain of the tested cable 200, causing the strain to change at a set rate or waveform.

[0077] The range of the strain setting rate is 0.1%-1%, that is, the controlled strain can be changed according to the set value of 0.1%, 0.2%, etc.

[0078] Optionally, the tensile loading module 2 includes a tensile loading controller, a high-precision load sensor, and a fiber optic strain sensor. The tensile loading controller is communicatively connected to the fiber optic strain sensor, the high-precision load sensor, and the hydraulic servo device to implement a strain control mode or a load control mode. The switching condition between the strain control mode and the load control mode can be based on a load threshold or material properties.

[0079] For example, switching based on load threshold:

[0080] When the load is less than 1kN, it automatically switches to strain control mode;

[0081] When the load is ≥1kN and ≤50kN, load control is enabled.

[0082] For example, switching based on material properties:

[0083] The initial stage of stretching the cable 200 (elastic deformation stage) is controlled by load (force value increases linearly);

[0084] When entering the yield stage or plastic deformation stage (force growth slows down), it automatically switches to strain control (to ensure accurate deformation).

[0085] It should also be noted that both the strain control mode and the load control mode can be controlled using a closed-loop PID control algorithm.

[0086] Example 4

[0087] This embodiment is basically the same as the third embodiment, except that this embodiment provides a collaborative loading mode of a tensile loading module 2 and a bending loading module 3 .

[0088] Furthermore, the loading waveform of the tensile drive device 21 includes a sine wave and a triangular wave; the loading waveform of the arc pressure block drive device 31 includes a sine wave and a square wave; the cable aging test device also includes a phase difference controller; the phase difference controller is communicatively connected to the tensile drive device 21 and the arc pressure block drive device 31 respectively and is used to control the phase difference between the tensile drive device 21 and the arc pressure block drive device 31 to adjust the tensile-bending timing applied to the cable 200, simulating the wave impact coupling stress.

[0089] The tensile drive device 21 and the arc pressure block drive device 31 are synchronized in hard real time through a phase difference controller, with a time deviation of less than 0.1s, which greatly reduces the composite stress simulation error caused by timing misalignment and reduces the matching error between tensile strain and bending strain, thereby making the aging test closer to the actual service status of the cable 200.

[0090] Example 5

[0091] like Figure 5 As shown, further, the temperature adjustment module 6 includes a liquid inlet pipe 61, a liquid outlet pipe 62, a circulating heat exchange system 63, a temperature detection device and a PID temperature control module; the circulating heat exchange system 63 is connected to the accommodating chamber 11 through the liquid inlet pipe 61 and the liquid outlet pipe 62 to drive the simulated seawater in the accommodating chamber 11 to circulate and be used to heat or cool the simulated seawater; the circulating heat exchange system 63 and the temperature detection device are respectively communicatively connected to the PID temperature control module; the circulating heat exchange system 63 responds to the control signal of the PID temperature control module and is used to adjust the temperature of the simulated seawater in the accommodating chamber 11 by injecting liquid into the accommodating chamber 11.

[0092] The circulating heat exchange system 63 includes a heat exchanger, a compressor built into the heat exchanger, and a resistance heater built into the heat exchanger. The heat exchanger, which circulates ethylene glycol solution, connects to the test chamber 1 via an inlet pipe 61 and an outlet pipe 62, forming a simulated seawater circulation loop. The simulated seawater within the test chamber 1 is drawn into the heat exchanger via the inlet pipe 61 and then returned to the test chamber 1 via the outlet pipe 62 after being heated or cooled. The compressor and resistance heater built into the heat exchanger regulate the temperature of the simulated seawater by adjusting the refrigerant flow rate or heating power. The compressor drives the refrigeration cycle, while the resistance heater provides direct heating. Together, they keep the simulated seawater within the range of 0-50°C. Temperature sensors evenly distributed throughout the test chamber 1 collect real-time temperature data and transmit it to the control system. A PID algorithm adjusts the operating power of the compressor and resistance heater to ensure a temperature change rate of ≤1°C / min. The circulating flow rate is adjustable within the range of 10-30 L / min via a regulating device on the pipe to ensure heat exchange efficiency and temperature uniformity.

[0093] As can be seen from the above-mentioned Example 3, when tensile loading module 2 is loading in strain control mode, the feedback strain value needs to be dynamically corrected based on the real-time temperature value, with a compensation factor of 0.05% / °C. When tensile loading module 2 operates in strain control mode, the mechanical properties of the material will change due to temperature (such as thermal expansion and contraction or changes in elastic modulus), resulting in a deviation between the actual deformation and the theoretical value at the same target strain. In this case, the target strain needs to be dynamically corrected based on the real-time temperature value—for every 1°C change in temperature, the target strain value is adjusted by 0.05% (i.e., a compensation factor of 0.05% / °C). For example, if the temperature rises by 10°C, the original target strain of 0.5% needs to be corrected to 0.5% + 10 × 0.05% = 0.55% to offset the temperature-induced change in material length, ensure that the actual loading strain is consistent with the test requirements, and guarantee data accuracy. This mechanism achieves dynamic compensation of target parameters by collecting real-time temperature data and embedding it in a closed-loop control algorithm, making it suitable for temperature-sensitive materials.

[0094] Example 6

[0095] like Figure 4 As shown, further, the salinity adjustment module 5 includes a pressurized nozzle 51, a deionized water injection valve 52 and a stirring paddle installed at the bottom of the accommodating chamber 11, the pressurized nozzle 51 is used to inject salt water into the accommodating chamber 11, the deionized water injection valve 52 is used to inject deionized water into the accommodating chamber 11, and the stirring paddle is used to stir the simulated seawater inside the accommodating chamber 11.

[0096] For example, the salinity adjustment module 5 also includes a salinity sensor and a salinity adjustment controller. The salinity sensor is used to detect the salinity of the simulated seawater. The salinity adjustment controller is communicatively connected to the salinity sensor, the pressurized nozzle 51, and the deionized water injection valve 52. It controls the activation of the pressurized nozzle 51 or the deionized water injection valve 52 based on feedback from the salinity value to achieve dynamic correction.

[0097] For example, the pressurized nozzle 51 can inject an artificial seawater solution with a salinity of 5% into the test tank 1 at a rate of 1-10 L / min.

[0098] For example, during the experiment, the relative salinity of the simulated seawater was 3.5%±2%.

[0099] Example 7

[0100] like Figure 6 As shown, further, the voltage output module 4 includes a high-frequency voltage generator and a conductor connection assembly 41; the conductor connection assembly 41 includes a plurality of arc-shaped graphite pressing blocks 411, and the plurality of arc-shaped graphite pressing blocks 411 are used to surround the conductor 201 of the cable 200 in the circumferential direction and clamp the conductor 201 of the cable 200 with a preset pressure; the high-frequency voltage generator outputs voltage to the cable 200 through the plurality of arc-shaped graphite pressing blocks 411.

[0101] Furthermore, the high-frequency voltage generator is configured to have adjustable output voltage and output frequency.

[0102] For example, the insulation layer of the terminal section of cable 200 is stripped to expose conductor 201. The conductor connection assembly 41 utilizes several split, curved graphite pressing blocks 411. A hydraulic cylinder applies driving force, pressing these blocks 411 against the outer circumference of conductor 201 at a preset pressure of 10-50 kN. A built-in pressure sensor in the clamping mechanism between these blocks 411 and conductor 201 monitors clamping force fluctuations in real time and automatically adjusts the pressure if deviations are excessive. An arc-shaped groove is provided inside the curved graphite pressing blocks 411 to match the cross-section of conductor 201, enhancing electrical contact stability under dynamic loading.

[0103] The voltage output module 4 is used to apply an adjustable high-frequency voltage to the cable 200. The high-frequency voltage generator outputs the required composite voltage waveform to achieve continuous adjustment of the peak voltage from 0 to 220 kV.

[0104] The voltage output module 4 also includes a contact resistance detection module electrically connected to the conductor connection assembly 41, which is used to detect the contact resistance between the conductor connection assembly 41 and the conductor 201. When the contact resistance detection module detects a resistance deviation greater than 5%, it triggers a safety shutdown, ensuring the reliability and repeatability of the multi-field coupling test.

[0105] Example 6

[0106] like Figure 4 As shown, the cable aging test device 100 also includes a central controller 7, which is communicatively connected to the tensile loading module 2, the bending loading module 3, the voltage output module 4, the salinity adjustment module 5, and the temperature adjustment module 6 to synchronously control mechanical and electrical stresses and environmental parameters, with a control time deviation of less than 0.1s. The central controller 7 synchronously coordinates temperature, salinity parameters, tensile force, bending curvature, and output voltage with a time deviation of less than 0.1s. For example, when the temperature rises, the heating power is automatically reduced and the solution flow rate is increased to avoid the superposition of thermal stress and runaway, and an alarm is triggered in the event of an abnormality. This module uses a sophisticated PID control system to accurately reproduce the multi-factor synergistic aging effect on the seabed.

[0107] Example 5

[0108] This embodiment provides a cable aging test method, which is applied to the above-mentioned cable aging test device 100 and includes the following steps:

[0109] S1: Sample installation: After the two ends of the cable 200 are respectively inserted into the cable interface 13 of the test box 1, the test box 1 is filled with simulated seawater;

[0110] S2: Composite stress loading and environmental control: applying axial tensile force to the cable 200 via the tensile loading module 2; bending the cable 200 via the bending loading module 3; outputting voltage to the cable 200 via the voltage output module 4; and controlling the salt concentration and temperature of the simulated seawater in which the cable 200 is immersed via the salinity adjustment module 5 and the temperature adjustment module 6;

[0111] S3: Process monitoring: collecting the strain distribution on the surface of the cable 200 in real time through the optical fiber strain sensor;

[0112] S4: Test endpoint detection:

[0113] The partial discharge detector disposed in the accommodating cavity 11 records the discharge amount. When the actual discharge amount detected by the partial discharge detector reaches a discharge threshold within a preset detection period, the cable 200 is determined to be defective and the test is terminated.

[0114] Alternatively, the test is terminated when the combined stress is applied for a preset time.

[0115] The following combination Figures 1-6 A specific embodiment will be described below.

[0116] As can be seen from the above embodiment, the cable 200 is passed through the test box 1 , and the cable 200 is placed on two cable support structures 33 .

[0117] The conductors 201 at both ends of the cable 200, located outside the test chamber 1, were inserted into a number of split, curved graphite blocks 411. A hydraulic press applied a constant clamping force, maintaining a contact resistance of 0.05 mΩ or less. Subsequently, a series of stainless steel clamps 221 were adjusted to the cable 200 armor and tightened using an adjustable bidirectional screw 222, maintaining a clamping force greater than the set tensile parameter for the test.

[0118] After the end of the cable 200 is clamped, the target parameters are input through the industrial computer interface of the central controller 7: an axial tensile force is applied to the cable 200 through the tensile loading module 2; the cable 200 is bent through the bending loading module 3; a voltage is output to the cable 200 through the voltage output module 4; the salt concentration and temperature of the simulated seawater in which the cable 200 is immersed are controlled through the salinity adjustment module 5 and the temperature adjustment module 6; after the system self-test passes, the communication response time between each module and the central controller 7 and the sensor zero drift are verified.

[0119] Central controller 7 sends a synchronous trigger command, synchronously activating the tension drive device 21, the arc-shaped pressure block drive device 31, the high-frequency voltage generator, the salinity adjustment module 5, and the temperature adjustment module 6. Throughout the test, a fiber optic strain sensor located in chamber 11 collects surface strain distribution data on cable 200 at a sampling rate of 5 Hz, with a spatial resolution of 1 cm. This sensor generates a real-time strain-time curve and monitors bending strain gradient deviation.

[0120] The partial discharge detector records the discharge amount. When the discharge threshold is reached within a single cycle, it is determined that there is a defect in the insulation layer and a safety shutdown is triggered, or the machine is shut down after continuous loading for a preset aging time.

[0121] The shutdown process is as follows:

[0122] First, the high-frequency voltage output is interrupted, and then the clamp 221 releases the load, simultaneously adjusting the liquid in the chamber 11 to a normal temperature and salt-free state. Specifically, the central controller 7 sequentially executes the shutdown procedure: the voltage output module 4 is grounded and discharged to 0 kV, the tensile loading module and the bending loading module drive the cable 200 to their initial positions, the temperature and salinity control are disabled, and waste liquid discharge is initiated.

[0123] After unlocking the cable clamp assembly 22 and conductor connection assembly 41, slowly remove the cable 200 and immediately clean the contact surface of the conductor 201 with isopropyl alcohol to prevent residual corrosion. During the device reset phase, the residual medium in the environmental chamber is purged, the sensors are reset to standby mode, and a multi-source data integration report (including strain distribution, partial discharge, and corrosion rate curves) is generated, providing a quantitative basis for cable aging assessment.

[0124] Through the above design, this method can simultaneously reproduce the mechanical stress, electrical stress and temperature-humidity coupling effects in accelerated aging tests, providing high-fidelity experimental support for the design optimization and operation and maintenance strategy of submarine cables 200.

[0125] The present invention solves the problems of low multi-physical field coupling synchronization accuracy, poor dynamic sealing and long test cycle in submarine cable aging test devices in related technologies by integrating mechanical dynamic loading, high-frequency electrical stress output and environmental multi-parameter coupling control: the hard real-time synchronization technology of the central controller 7 is adopted to achieve precise coordinated loading of tensile / bending mechanical loads, high-frequency voltage and temperature and humidity seawater environment, and the matching error between tensile strain and bending curvature is small; the dynamic sealing structure 14 of the test box 1 is designed by combining multi-stage rubber and lubricating sealing rings to maintain a high sealing level under alternating loads, while the conductor 2 The 01 fixture uses a split graphite pressing block and a stainless steel clamp to ensure that the contact resistance fluctuation is less than 2% and the sample cable has no obvious slippage during continuous testing; the environmental control module uses the PID linkage adjustment of the heat exchanger and the seawater salinity compensator to achieve temperature changes of ≤1℃ / min and dynamic correction of salinity deviation. It can accurately reproduce the full-condition aging process of the submarine cable 200 from static bending during laying to dynamic impact during operation. The test cycle is shortened by more than 60% compared with traditional methods, and the data repeatability error is small, providing a high-fidelity and high-efficiency testing platform for the reliability evaluation of the high-voltage submarine cable 200.

[0126] The remaining components and operations of the cable aging tester 100 according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here. In the description of the present invention, "first feature" and "second feature" may include one or more of these features. The vertical, horizontal, and front-to-back directions are based on the vertical, horizontal, and front-to-back directions shown in the figure.

[0127] In the description of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature therebetween. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is at a higher level than the second feature.

[0128] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0129] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A cable aging test device, characterized in that: include: A test box (1) is provided with a accommodating chamber (11), and cable interfaces (13) are provided on two opposite walls (12) of the test box (1), the two cable interfaces (13) are connected to the accommodating chamber (11), and the center lines of the two cable interfaces (13) are coaxial, the two cable interfaces (13) are used to seal and connect cables (200) so that the cables (200) are installed in the accommodating chamber (11), and the accommodating chamber (11) is also used to fill simulated seawater to immerse the cables (200); a tensile loading module (2), disposed outside the test box (1) and used to apply an axial tensile force parallel to the centerline to the cable (200); A bending loading module (3) is provided in the accommodating cavity (11) and comprises an arc-shaped pressing block driving device (31) and an arc-shaped pressing block (32), wherein the arc-shaped pressing block driving device (31) is used to drive the arc-shaped pressing block (32) to press against the cable (200) arranged in the accommodating cavity (11); a voltage output module (4), disposed outside the test box (1) and used to output voltage to the conductor (201) of the cable (200); a salinity adjustment module (5), disposed in the accommodating chamber (11) and used for injecting salt water or deionized water into the accommodating chamber (11); The temperature regulating module (6) is used to regulate the temperature of the simulated seawater in the accommodating chamber (11).

2. The cable aging test device according to claim 1, characterized in that: The bending loading module (3) further includes two cable support structures (33) provided in the accommodating cavity (11); The two cable support structures (33) are spaced apart along the center line and are used for laying cables (200).

3. The cable aging test device according to claim 2, characterized in that: The cable support structure (33) comprises a support column (331) fixedly connected to the bottom of the accommodating cavity (11) and a support wheel (332) rotatably arranged on the top of the support column (331); A supporting V-shaped groove (3321) is defined on the circumferential surface of the supporting wheel (332) and is used to apply a supporting force to the cable (200) at least along a direction opposite to the bottom of the accommodating cavity (11); The arc-shaped pressing block driving device (31) is used to drive the arc-shaped pressing block (32) to move, so that the cable (200) mounted between the two cable support structures (33) moves closer to or farther from the bottom of the accommodating cavity (11).

4. The cable aging test device according to claim 1, characterized in that: The bending loading module (3) further includes a bending loading controller and a laser displacement sensor (333) provided at the end of the arc-shaped pressing block (32) in the arc-shaped extension direction; The laser displacement sensor (333) is used to detect the curvature of the cable (200); The bending loading controller is communicatively connected to the laser displacement sensor (333) and the arc-shaped pressing block driving device (31), and the bending loading controller is configured to control the arc-shaped pressing block driving device (31) to change according to a set displacement or waveform based on the feedback curvature, thereby controlling the curvature of the cable (200).

5. The cable aging test device according to claim 1 or 4, characterized in that: The tensile loading module (2) comprises a tensile driving device (21) and a cable clamping assembly (22); There are two cable clamping assemblies (22) and they are used to fix two ends of the connecting cable (200) respectively; The stretching drive device (21) is fixedly connected to at least one of the cable clamping assemblies (22) and drives the cable clamping assembly (22) to move along the center line to apply an axial tensile force parallel to the center line to the cable (200); The tensile loading module (2) further comprises a tensile loading controller and a high-precision load sensor; the high-precision load sensor is provided between the output end of the tensile driving device (21) and the cable clamping assembly (22) to collect the tensile force; the tensile loading controller is in communication with the high-precision load sensor and the tensile driving device (21) to control the driving force of the tensile driving device (21) in a closed loop according to the feedback load force signal of the high-precision load sensor, thereby controlling the tensile force applied to the cable (200) so that the force value changes according to a set value or waveform; And\or, the tensile loading module (2) includes a tensile loading controller and an optical fiber strain sensor; the optical fiber strain sensor is arranged in the accommodating cavity (11) to detect the strain of the cable (200); the tensile loading controller is in communication with the optical fiber strain sensor and the tensile driving device (21) to control the driving force of the tensile loading driving device in a closed loop according to the feedback strain signal of the optical fiber strain sensor, thereby directly controlling the strain of the cable (200) so that the strain changes according to a set rate or waveform.

6. The cable aging test device according to claim 5, characterized in that: The loading waveform of the stretching drive device (21) includes a sine wave and a triangle wave; The loading waveform of the arc-shaped pressing block driving device (31) includes a sine wave and a square wave; The cable aging test device further includes a phase difference controller; The phase difference controller is communicatively connected to the stretching drive device (21) and the arc-shaped pressing block drive device (31) and is used to control the phase difference between the stretching drive device (21) and the arc-shaped pressing block drive device (31) to adjust the stretching-bending timing applied to the cable (200).

7. The cable aging test device according to claim 1, characterized in that: The temperature regulating module (6) comprises a liquid inlet pipe (61), a liquid outlet pipe (62), a circulating heat exchange system (63), a temperature detection device and a PID temperature control module; The circulating heat exchange system (63) is connected to the accommodating chamber (11) via the liquid inlet pipe (61) and the liquid outlet pipe (62) to drive the simulated seawater in the accommodating chamber (11) to circulate and be used to heat or cool the simulated seawater; The circulating heat exchange system (63) and the temperature detection device are respectively communicatively connected to the PID temperature control module; The circulating heat exchange system (63) responds to the control signal of the PID temperature control module and is used to adjust the temperature of the simulated seawater in the accommodating chamber (11) by injecting liquid into the accommodating chamber (11).

8. The cable aging test device according to claim 1, characterized in that: The salinity adjustment module (5) comprises a pressurized nozzle (51), a deionized water injection valve (52), and a stirring paddle installed at the bottom of the accommodating chamber (11); the pressurized nozzle (51) is used to inject salt water into the accommodating chamber (11); the deionized water injection valve (52) is used to inject deionized water into the accommodating chamber (11); and the stirring paddle is used to stir the simulated seawater inside the accommodating chamber (11).

9. The cable aging test device according to claim 1, characterized in that: The voltage output module (4) includes a high-frequency voltage generator and a conductor connection component (41); The conductor connection assembly (41) comprises a plurality of arc-shaped graphite pressing blocks (411), wherein the plurality of arc-shaped graphite pressing blocks (411) are used to surround the conductor (201) of the cable (200) in a circumferential direction and clamp the conductor (201) of the cable (200) with a preset pressure; The high-frequency voltage generator outputs voltage to the cable (200) through the plurality of arc-shaped graphite pressing blocks (411).

10. A cable aging test method, applied to the cable aging test device according to any one of claims 1 to 9, comprising the following steps: S1: Sample installation: After the two ends of the cable (200) are respectively inserted into the cable interface (13) of the test box (1), the test box (1) is filled with simulated seawater; S2: composite stress loading and environmental control: applying an axial tensile force to the cable (200) through the tensile loading module (2); bending the cable (200) through the bending loading module (3); outputting a voltage to the cable (200) through the voltage output module (4); and controlling the salt concentration and temperature of the simulated seawater in which the cable (200) is immersed through the salinity adjustment module (5) and the temperature adjustment module (6); S3: process monitoring: collecting the strain distribution on the surface of the cable (200) in real time through an optical fiber strain sensor; S4: Test endpoint detection: The discharge amount is recorded by a partial discharge detector arranged in the accommodating cavity (11), and when the actual discharge amount of the partial discharge detector detected within a preset detection cycle reaches a discharge threshold, it is determined that the cable (200) has a defect and the test is terminated; Alternatively, the test is terminated after the load reaches the preset aging time.

Images