High-voltage cable accessory degradation acceleration tank device and degradation evaluation method

Abstract

The invention relates to the technical field of power cable degradation evaluation, and particularly discloses a high-voltage cable accessory degradation acceleration tank device and a degradation evaluation method.The high-voltage cable accessory degradation acceleration tank device comprises a tank body and electrolyte, a containing cavity used for installing a cable accessory is formed in the tank body, and the containing cavity is filled with the electrolyte; the two ends of the to-be-tested cable accessory are connected with the high-voltage cable. An observation window for observing cable accessories is arranged on the surface of the tank body; a temperature control module is arranged in the tank body and is used for adjusting the temperature, humidity and pressure in the tank body; and a liquid inlet and a liquid outlet which are communicated with the accommodating cavity are respectively formed in the top and the bottom of the tank body and are used for adjusting the pH value of the electrolyte and taking and discharging the electrolyte. According to the high-voltage cable accessory degradation acceleration tank device and the degradation evaluation method provided by the invention, the temperature and the pH value of the electrolyte and the pressure in the tank can be changed, various complex working conditions can be simulated, and the influence of a difference deterioration environment on the high-voltage cable accessory can be evaluated in a short time.

Description

Technical Field

[0001] The invention relates to a high-voltage cable accessory accelerated degradation tank device and an accelerated degradation method, belonging to the technical field of power cable degradation assessment. Background Art

[0002] Submarine cables are widely used in the power supply system from the mainland to the islands and in large-scale power transmission and transformation projects across rivers and seas. They are of great significance for the transmission of clean energy and improving the reliability of power supply to islands. Regional interconnection of island power supply systems is achieved through submarine cable projects of different voltage levels at home and abroad. When high-voltage submarine cables are in operation, the circulation is large and the heating phenomenon is prominent, which will cause the insulation medium performance of the submarine cables to gradually deteriorate during operation. The aging effect of electrothermal stress leads to irreversible decline in insulation performance, resulting in internal insulation problems of submarine cables and threatening the normal operation of submarine cables.

[0003] Previous studies have shown that in harsh environments such as immersion, high humidity, and high pollution, the metal parts (copper tail pipes, lead seals, and aluminum sleeves) of high-voltage cable accessories (joints and terminals) are very susceptible to corrosion and water degradation. The mechanism is mainly the oxidation reaction of the anode metal caused by the electrochemical / galvanic effect. The water-soluble electrolyte accelerates the process of the reaction, seriously affecting the safety and reliability of the accessories and the safety and stability of the grounding loop. Due to the particularity of the environment, submarine cables have the characteristics of difficult fault location, cumbersome maintenance, and huge time consumption. If a cable accessory accelerated aging device that simulates the working conditions of submarine cables can be established, it will be able to save a lot of costs and have important engineering value. However, the existing aging devices have relatively single functions and cannot truly and effectively simulate the complex working conditions of the seabed. Therefore, if an accelerated aging device with an adjustment device that can simulate a variety of submarine working conditions can be invented, and at the same time, based on the temperature and pressure control strategy, it can evaluate the impact of differentiated harsh environments on high-voltage cable accessories in a short time, it will be of great significance. Summary of the invention

[0004] In order to solve the problem in the prior art that it is impossible to simulate various working conditions and effectively accelerate the aging of submarine cable accessories, the present invention provides a high-voltage cable accessory accelerated degradation tank device and a degradation assessment method, which can change the temperature, pH value and tank pressure of the electrolyte, simulate various complex working conditions, and evaluate the impact of differential deterioration environments on high-voltage cable accessories in a short time.

[0005] The present invention adopts the following technical solution.

[0006] In the first aspect, the present invention provides a high-voltage cable accessory accelerated degradation tank device, comprising: a tank and an electrolyte, wherein the tank is provided with a containing cavity for installing cable accessories, and the electrolyte is filled in the containing cavity; both ends of the cable accessories to be tested are connected to the high-voltage cable; both ends of the tank located at the containing cavity are provided with an inlet and an outlet for the high-voltage cable to pass through, and sealing devices are provided at the inlet and the outlet; the surface of the tank is provided with an observation window for observing the cable accessories; a temperature control module is provided inside the tank for adjusting the temperature, humidity and pressure inside the containing cavity; the top and bottom of the tank are respectively provided with a liquid inlet and a liquid outlet connected to the containing cavity, so as to adjust the pH value of the electrolyte and to take in and out the liquid.

[0007] Preferably, the temperature control module comprises: a temperature measuring module; the temperature measuring module is arranged on both sides of the tank body near the inlet and the outlet, and is used to detect the ambient temperature of the accommodating cavity from multiple locations simultaneously.

[0008] Preferably, the temperature control module further comprises: a heating module; the heating modules are evenly arranged at equal intervals on the bottom of the accommodating cavity, so as to evenly heat the accommodating cavity.

[0009] Preferably, a pressure gauge is provided on the top of the tank body, and a detection end of the pressure gauge extends into the accommodating cavity to detect the pressure in the accommodating cavity.

[0010] Preferably, the tank body is further provided with an air intake port; the air intake port and the liquid inlet are the same port or two independent ports, and the air intake port is communicated with the interior of the accommodating cavity.

[0011] Preferably, the observation window is made of organic glass for use in ultrasonic flaw detection.

[0012] In a second aspect, the present invention provides a method for evaluating accelerated degradation of a high-voltage cable accessory, using the high-voltage cable accessory accelerated degradation tank device of the preceding claim, comprising the following steps:

[0013] Adjust the temperature inside the tank based on the temperature control module to test the aging degree of cable accessories at different temperatures;

[0014] Based on the liquid inlet and outlet, adjust the pH value of the electrolyte in the tank and test the aging degree of cable accessories under different pH values;

[0015] Based on the observation window, the cable accessory image data is collected, and the morphological edge detection algorithm is improved by using the non-local mean denoising algorithm. The collected cable accessory images are subjected to morphological edge denoising for subsequent identification of cable defective parts.

[0016] Preferably, the morphological edge detection algorithm is improved by using a non-local mean denoising algorithm, and morphological edge denoising is performed on the collected cable accessory image, including the following steps:

[0017] Perform preliminary denoising on the image based on morphological opening operation to obtain the reconstructed background image;

[0018] Performing a difference operation between the image to be tested and the reconstructed background image to obtain a desired image;

[0019] In the obtained expected image, a differential threshold is introduced to judge the normal part and the defective part of the cable, so as to determine the defective area of ​​the cable accessories.

[0020] Preferably, the differential threshold determination method is as follows:

[0021]

[0022] In the formula, f out (i, j) is the defect segmentation image with the difference threshold introduced, f(i, j) is the original image, g2(i, j) is the reconstructed background image, T SE is the set difference threshold;

[0023] If the pixel grayscale value of the image is less than the set differential threshold, the cable accessory is considered to be free of defects; if the pixel grayscale value of the image is greater than the set differential threshold, the cable accessory is considered to be defective.

[0024] Preferably, the degradation assessment method further comprises the following steps:

[0025] Using an observation window made of organic glass, ultrasonic flaw detection is performed on cable accessories based on the transmission of ultrasonic waves through the organic glass to detect internal defects of cable accessories.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention facilitates the adjustment of the pH value of the electrolyte inside the accommodating chamber by setting a liquid inlet and a liquid outlet on the tank body that are connected to the accommodating chamber, thereby facilitating the testing of the aging degree of the cable accessories under different pH values; by setting a temperature control module, it is not only convenient to adjust the temperature inside the accommodating chamber, but also to adjust the humidity and pressure inside the accommodating chamber, thereby simulating the aging degree of the cable accessories under complex working conditions of different temperatures, different humidity and different pressures. Through the changes in pH value, temperature, humidity and pressure, the aging of the cable accessories is analyzed from multiple angles, so as to evaluate the impact of different environments on the high-voltage cable accessories in a short time and find the environment that accelerates the aging of the cable accessories the fastest.

[0027] In addition, the tank body is also provided with a gas intake port, through which the gas inside the tank body can be collected for further qualitative analysis of the type and quantitative detection of the content.

[0028] In order to facilitate the detection of cable accessories, the present invention is also provided with an observation window made of organic glass, through which the internal defects of the cable accessories can be detected based on ultrasonic flaw detection. The cable accessory image is collected using the observation window, and the morphological edge denoising is performed on the collected cable accessory image using an improved morphological edge detection algorithm, which is conducive to the subsequent identification of cable defective parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a high-voltage cable accessory accelerated degradation tank device in the present invention.

[0030] Description of reference numerals:

[0031] 1. High-voltage cable; 2. Sealing device; 3. Temperature measuring module; 4. Liquid inlet; 5. Pressure gauge; 6. Pressure reducing valve; 7. Heating module; 8. Cable connector; 9. Observation window; 10. Electrolyte; 11. Liquid outlet. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0033] Example 1

[0034] Combination Figure 1 The embodiment of the present invention provides a design example of a high-voltage cable accessory accelerated degradation tank device. The degradation tank device is composed of a tank, a sealing device 2, a temperature measurement module 3, a heating module 7, a liquid inlet 4, a high-voltage cable 1, a cable connector 8, a barometer 5, a pressure reducing valve 6, a liquid outlet 11, an observation window 9, and an electrolyte 10.

[0035] Figure 1 In the embodiment, a accommodating cavity is provided inside the tank body, and high-voltage cable accessories (taking cable connector 8 as an example) are provided inside the tank body, and two ends thereof are respectively connected to two high-voltage cables 1. An inlet and an outlet for the two high-voltage cables 1 to pass through are respectively provided at both ends of the tank body. To ensure the sealing performance of the tank body, a sealing device 2 is added to the inlet and outlet of the tank body, and the inner wall of the sealing device 2 contacts and seals the outer surface of the high-voltage cable 2.

[0036] In a preferred but non-limiting embodiment of the present invention, the sealing device 2 is made of EPDM low-smoke halogen-free environmentally friendly material, and has flame retardant, sealing, fireproof, waterproof and other functions. The sealing device 2 is placed at the inlet and outlet of the cable passing through the tank body, which can achieve sealing protection against fire, water and gas leakage; the sealing device 2 is manufactured in a standardized manner and installed in an installation frame, a wedge block is added to the top of the installation frame, and a socket wrench is used to expand the wedge block, and the high-voltage cable 1 is fixed in place by squeezing.

[0037] Temperature measuring modules 3 are provided on both sides of the tank body close to the inlet and the outlet. By providing a plurality of temperature measuring modules 3, it is ensured that the temperature at various locations in the tank body can be accurately measured.

[0038] The interior of the tank cavity is filled with electrolyte 10, and the top of the tank is provided with a liquid inlet 4 and an air outlet connected to the cavity, which can be the same port or two independent ports, and the liquid inlet 4 and the air outlet are provided with corresponding valves.

[0039] A liquid outlet 11 is provided at the bottom of the tank body and near the outlet side. The liquid outlet 11 is also connected to the accommodating cavity. The liquid outlet 11 is provided with a valve to discharge the electrolyte 10 in the tank body. In addition, the liquid inlet 4 and the liquid outlet 11 cooperate with each other to change the composition, pH value, etc. of the electrolyte in the tank body, which is used to simulate the complex environment under different working conditions; the gas in the tank body can be enriched and collected through the gas extraction port, so as to detect the composition and content of the gas.

[0040] Furthermore, the tank body is also equipped with a pressure gauge 5, which is arranged on the top of the tank body, and its detection end extends into the interior of the accommodating cavity, so as to monitor the air pressure in the tank body in real time; in order to avoid excessive pressure in the tank body, an air outlet port is arranged at the rear end of the tank body (the end close to the outlet), and the air outlet port is provided with a pressure reducing valve 6.

[0041] A plurality of heating modules 7 are evenly arranged at the bottom of the tank's accommodating cavity, preferably three heating modules 7 are provided, and the heating modules 7 and the temperature measuring module 3 together constitute a temperature control module, which can be used to heat the temperature inside the tank. At the same time, when the temperature rises, the volatilization of the electrolyte is accelerated, which can change the humidity and pressure inside the tank. Through reasonable temperature, pressure, and humidity control strategies, the temperature, pressure, and humidity inside the tank can be changed to simulate a harsh environment and accelerate the aging of cable accessories.

[0042] In a preferred but non-limiting embodiment of the present invention, an observation window 9 made of organic glass is provided on the side wall of the tank body. The observation window 9 is arranged correspondingly in front of the high-voltage cable 1, so that the aging degree of the cable accessories can be easily observed.

[0043] Based on the developed device, by selecting reasonable control strategies, it is possible to evaluate the impact of differentiated harsh environments on high-voltage cable accessories in a short time, and explore the use of characteristic gas analysis, material composition analysis and other methods as effective means to evaluate the degradation of cable accessory grounding components.

[0044] Example 2

[0045] The embodiment of the present invention provides a method for evaluating the accelerated degradation of a high-voltage cable accessory, using the high-voltage cable accessory accelerated degradation tank device in Embodiment 1, comprising the following steps:

[0046] Based on the configured temperature measurement module 3, with the help of a signal converter, the temperature inside the tank can be transmitted to the control system in real time. In conjunction with the central controller, the heating module can be controlled to test the aging degree of cable accessories at different temperatures and clarify the mechanism of temperature aging cables.

[0047] Based on the liquid inlet 4 and the liquid outlet 11, the cable accessories aging test under different pH conditions can be traversed and the data can be saved. Based on the test data, the aging mechanism of the cable accessories under extreme conditions can be analyzed to fill the data gap in the industry.

[0048] Simulate complex working conditions, test the aging data of cable accessories under different temperatures, different pH values, and different currents, and organize and analyze the data to establish the insulation aging assessment rules for cable accessories;

[0049] Based on observation window 9, with the help of improved image recognition technology, through non-local mean denoising algorithm and improved morphological edge detection algorithm, the ability to focus on defective parts is improved, and the efficiency and accuracy of cable joint defect detection are improved;

[0050] The observation window is made of plexiglass, which transmits ultrasonic waves, making it convenient to use ultrasonic flaw detection equipment for non-destructive testing. It can detect defects inside cable accessories, such as internal cracks, voids, etc., and display the distribution of internal defects through images, with safety and defect detection capabilities.

[0051] Furthermore, the evaluation of insulation aging of cable accessories mainly involves the evaluation of the insulation status and life of the cable, which includes two aspects: detection method and life evaluation.

[0052] Insulation status detection method:

[0053] Insulation resistance test: By applying DC high voltage at both ends of the cable, the resistance value of the insulation layer is measured to determine whether the insulation condition is good. When there is a problem with the insulation condition, the insulation resistance value will drop significantly.

[0054] Dielectric strength test: By applying high voltage to detect the maximum voltage value that the cable can withstand, it can be visually determined whether the insulation is damaged.

[0055] Capacitance test: The insulation status is determined by measuring the change in capacitance. Insulation problems can cause capacitance changes.

[0056] Dielectric loss test: By measuring the loss of insulating materials in an AC electric field, aging damage can be detected in a timely manner.

[0057] Lifespan Assessment:

[0058] Material aging analysis: Determine the service life of the cable by analyzing the aging degree of the cable insulation material.

[0059] Thermal aging test: The cable is subjected to a long-term accelerated aging test in a high temperature environment to simulate long-term use in a high temperature environment.

[0060] Dynamic thermal response test: Rapidly change the cable temperature, observe changes in insulation status, and evaluate service life.

[0061] Dynamic electrical performance test: Evaluate the cable's short-term tolerance and observe the cable performance through rapid temperature changes.

[0062] Taking (4) as an example, using the observation window and based on the improved image recognition technology, the steps for detecting cable accessory defects are as follows:

[0063] Step 1: Data acquisition, collecting cable accessory image data.

[0064] In this step, on the one hand, the aging test can be carried out by the device of the present invention to collect data, and on the other hand, the data can be collected by on-site photography.

[0065] Step 2: Image preprocessing: perform morphological opening operation on the image to remove noise and obtain the reconstructed background image.

[0066] The present invention adopts non-local mean denoising, expands the traditional local and semi-local calculation models to non-local calculation models, and uses the similarity of two image blocks to calculate the filtering weights. This method can better remove noise while keeping important information such as texture and edges in the original image from being blurred:

[0067] For pixel i in the image, N(i) represents the image block with a range of n×n centered on i, and N(j) is the image block in the neighborhood of N(i). The Gaussian weighted Euclidean distance between N(i) and N(j) is used to measure the similarity between i and j.

[0068] Assume that the denoised image is g(i), and the image before denoising is f={f(i)|i∈Ω}, Ω is the image area, f(i) represents the gray value of pixel i, and the non-local mean can be expressed as:

[0069]

[0070] Among them, i represents a pixel in the image, N(i) represents an image block with a size of n×n centered on i, N(j) is an image block in the neighborhood of N(i), a represents the standard deviation of the Gaussian kernel function, d(i,j) represents the Euclidean distance between image blocks, h is the filtering parameter, and w(i,j) is the weight coefficient corresponding to pixel j.

[0071] On this basis, gamma correction is performed to improve the image contrast. A fixed γ value is selected to correct the image. When the γ value is greater than 1, the overall brightness of the image is increased; when the γ value is less than 1, the overall brightness of the image is reduced. After the image is gamma-corrected, due to the fixed γ value, the image can be brighter or darker overall. The definition of gamma correction is:

[0072]

[0073] Step 3: Build a dataset to create a labeled dataset containing various defect types for training and validating the model.

[0074] Step 4: Model improvement. Based on the improved morphological edge detection algorithm, morphological edge detection is performed on the collected cable accessory images to locate the positions of small defects. Then, threshold segmentation is performed to obtain a binary image, laying the foundation for subsequent defect identification.

[0075] The specific implementation method is as follows:

[0076] Perform a difference operation on the image to be tested and the reconstructed background image. During the difference operation, avoid directly subtracting the original image from the background image. Use a certain judgment method to determine whether the pixels in the image are background or defect areas, adaptively perform a difference operation on the image, and segment out the defect area.

[0077] Due to the discontinuity of the grayscale value at the edge, there will be a certain grayscale change at the edge of weak scratches or impurities. Based on this feature, in the process of differential operation between the image to be tested and the reconstructed background image, by adding a certain differential threshold for judgment, the background area and the defect area can be distinguished in the differential operation, and the original grayscale value of the area with a large grayscale value change, that is, the defect area, can be retained to prevent the information of weak scratches or impurities from being weakened during the differential operation.

[0078] The determination method of the difference threshold of this process is as follows:

[0079]

[0080] In the above formula, f out (i, j) is the defect segmentation image with the difference threshold introduced, f(i, j) is the original image, g2(i, j) is the reconstructed background image, T SE is the set difference threshold.

[0081] If the pixel grayscale value of the image is less than the set differential threshold, the cable accessory is considered to be free of defects; if the pixel grayscale value of the image is greater than the set differential threshold, the cable accessory is considered to be defective.

[0082] On this basis, the image is binarized and segmented to obtain a binary image, thereby determining the defect area.

[0083] The differential threshold helps to accurately distinguish the normal part of the cable from the defective part, and the differential threshold can be changed manually or adaptively according to the requirements of the cable application scenario. It is set according to the accuracy required for defect detection. If the accuracy is high, it is set to a smaller value; otherwise, it is set to a slightly larger value. Specifically: in occasions where the cable application is more stringent, that is, the accuracy required for cable detection is higher, the threshold can be set to a smaller value; and in some occasions where the requirements are not strict, the threshold can be appropriately increased. If the threshold is too small, there is a possibility of misjudgment, that is, non-defective areas or extremely small defects allowed are judged as defective areas, and if the threshold is too large, there is a possibility that the defective area cannot be detected. By modeling and training this value, the optimal solution of this value can be found to improve the accuracy of defective area judgment. Compared with the existing methods, this method avoids the defects of conventional constant value setting and can improve the accuracy of detection.

[0084] In the improved morphological difference method, when performing a difference operation between the original image and the reconstructed background image, the difference threshold T is used. SE Defective areas with certain grayscale changes in the image are identified. Therefore, in the difference operation, the pixel grayscale value of the weak defect area can be retained, while the grayscale value of the background area is reduced, increasing the grayscale difference between the background and the defect. Step 5: Train the model, use the constructed data set to train the improved model, and optimize the loss function to improve the detection performance.

[0085] Step 6: Model evaluation, evaluate the performance of the model on the validation set and adjust parameters to optimize accuracy and efficiency.

[0086] Step 7: Result analysis, organize and summarize the data, such as the type, location and severity of defects.

[0087] The beneficial effect of the present invention is that, compared with the prior art, the present invention facilitates the adjustment of the pH value of the electrolyte inside the accommodating chamber by setting a liquid inlet and a liquid outlet connected to the accommodating chamber on the tank body, thereby facilitating the testing of the aging degree of the cable accessories under different pH values; by setting a temperature control module, it is not only convenient to adjust the temperature inside the accommodating chamber, but also to adjust the humidity and pressure inside the accommodating chamber, thereby simulating the aging degree of the cable accessories under complex working conditions of different temperatures, different humidity and different pressures. Through the changes in pH value, temperature, humidity and pressure, the aging of the cable accessories is analyzed from multiple angles, so as to evaluate the impact of different environments on the high-voltage cable accessories in a short time and find the environment that accelerates the aging of the cable accessories the fastest.

[0088] In addition, the tank body is also provided with a gas intake port, through which the gas inside the tank body can be collected for further qualitative analysis of the type and quantitative detection of the content.

[0089] In order to facilitate the detection of cable accessories, the present invention is also provided with an observation window made of organic glass, through which the internal defects of the cable accessories can be detected based on ultrasonic flaw detection. The cable accessory image is collected using the observation window, and the morphological edge denoising is performed on the collected cable accessory image using an improved morphological edge detection algorithm, which is conducive to the subsequent identification of cable defective parts.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high-voltage cable accessory accelerated degradation tank device, comprising: The tank and electrolyte (10) are characterized in that: The tank body is provided with a receiving cavity for installing cable accessories, and the receiving cavity is filled with electrolyte; both ends of the cable accessories to be tested are connected to the high-voltage cable (1); both ends of the tank body located at the receiving cavity are provided with an inlet and an outlet for the high-voltage cable to pass through, and the inlet and the outlet are provided with sealing devices (2); the surface of the tank body is provided with an observation window (9) for observing the cable accessories; The tank body is provided with a temperature control module for adjusting the temperature, humidity and pressure inside the tank body; The top and bottom of the tank body are respectively provided with a liquid inlet (4) and a liquid outlet (11) which are connected to the accommodating cavity, so as to adjust the pH value of the electrolyte and to take in and out the electrolyte.

2. The high-voltage cable accessory accelerated degradation tank device according to claim 1 is characterized in that: The temperature control module comprises: a temperature measurement module (3); The temperature measurement module (3) is arranged on both sides of the tank body near the inlet and the outlet, and is used to detect the ambient temperature of the accommodating cavity from multiple locations simultaneously.

3. The high-voltage cable accessory accelerated degradation tank device according to claim 1, characterized in that: The temperature control module further comprises: a heating module (7); The heating modules (7) are evenly arranged at equal intervals on the bottom of the accommodating cavity, and are used to evenly heat the accommodating cavity.

4. The high-voltage cable accessory accelerated degradation tank device according to any one of claims 1 to 3, characterized in that: A pressure gauge (5) is arranged on the top of the tank body, and a detection end of the pressure gauge (5) extends into the accommodating cavity to detect the pressure in the accommodating cavity.

5. The high-voltage cable accessory accelerated degradation tank device according to any one of claims 1 to 3, characterized in that: The tank body is also provided with an air intake port; the air intake port and the liquid inlet (4) are the same port or two independent ports, and the air intake port is connected to the interior of the accommodating cavity.

6. The high-voltage cable accessory accelerated degradation tank device according to any one of claims 1 to 3, characterized in that: The observation window (9) is made of organic glass and is used for ultrasonic flaw detection.

7. A method for evaluating accelerated degradation of high-voltage cable accessories, using the high-voltage cable accessories accelerated degradation tank device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Adjust the temperature inside the tank based on the temperature control module to test the aging degree of cable accessories at different temperatures; Based on the liquid inlet (4) and the liquid outlet (11), the pH value of the electrolyte in the tank is adjusted to test the aging degree of the cable accessories under different pH values; Based on the observation window (9), the cable accessory image data is collected, and the morphological edge detection algorithm is improved by using the non-local mean denoising algorithm to perform morphological edge denoising on the collected cable accessory image, so as to subsequently identify the defective parts of the cable.

8. The method for evaluating accelerated degradation of high-voltage cable accessories according to claim 7, characterized in that: The morphological edge detection algorithm is improved by using the non-local mean denoising algorithm, and the morphological edge denoising is performed on the collected cable accessory image, including the following steps: Perform preliminary denoising on the image based on morphological opening operation to obtain the reconstructed background image; Performing a difference operation between the image to be tested and the reconstructed background image to obtain a desired image; In the obtained expected image, a differential threshold is introduced to judge the normal part and the defective part of the cable, so as to determine the defective area of ​​the cable accessories.

9. The method for evaluating accelerated degradation of high-voltage cable accessories according to claim 8, characterized in that: The difference threshold determination method is as follows: In the formula, f out (i, j) is the defect segmentation image with the difference threshold introduced, f(i, j) is the original image, g2(i, j) is the reconstructed background image, T SE is the set difference threshold; If the pixel grayscale value of the image is less than the set differential threshold, the cable accessory is considered to be free of defects; if the pixel grayscale value of the image is greater than the set differential threshold, the cable accessory is considered to be defective.

10. The method for evaluating accelerated degradation of high-voltage cable accessories according to claim 7, characterized in that: The degradation assessment method further comprises the following steps: An observation window (9) made of organic glass is used to transmit ultrasonic waves through the organic glass, so as to perform ultrasonic flaw detection on the cable accessories and detect internal defects of the cable accessories.

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