Device for accelerated degradation detection of on-line monitoring device for dissolved gases in insulating oil

Abstract

The application provides an equipment for accelerated degradation detection of an on-line monitoring device for dissolved gas in insulating oil, comprising a control module, a characteristic gas component saturated dissolving tank and a plurality of oil sample cylinders containing mixed component oil samples with known standard concentrations; the characteristic gas component saturated dissolving tank is connected with the on-line monitoring device for dissolved gas in insulating oil to be detected; the on-line monitoring device for dissolved gas in insulating oil performs high-frequency and high-intensity saturated concentration component characteristic gas detection operation under the control of the control module, so as to accelerate the degradation of the on-line monitoring device for dissolved gas in insulating oil, and then the oil sample cylinders are detected after the degradation is completed; the control module evaluates the quality of the monitored device according to the working condition data of the monitored device in the accelerated degradation process and after the degradation; the application can perform accelerated degradation treatment on the on-line monitoring device for dissolved gas in insulating oil, and evaluate the operation reliability of the device according to the working condition performance of the monitored device in the treatment process and after the treatment.

Description

Technical Field

[0001] This invention relates to the field of online monitoring devices for large power transformers, and in particular to equipment for accelerated degradation detection in online monitoring devices for dissolved gases in insulating oil. Background Technology

[0002] As the most important equipment in the power grid, the main transformer (referred to as the main transformer) is always a key inspection target. The main transformer contains a large amount of insulating oil for insulation and cooling. When an overheating or discharge fault occurs inside the main transformer, the insulating oil around the fault point will undergo corresponding pyrolysis or cracking reactions due to the high temperature heat or discharge energy at the fault point, producing corresponding fault characteristic gases such as methane, ethane, ethylene, acetylene, hydrogen, carbon monoxide, and carbon dioxide. The more severe the fault and the longer the time, the more gases are produced.

[0003] During normal operation of a main transformer, the content of characteristic gases dissolved in the insulating oil inside is very low or non-existent. By using an online monitoring device for dissolved gases in the insulating oil to detect and analyze the content, proportion, and growth trend of these characteristic gases dissolved in the oil, it is possible to accurately determine whether a fault has occurred inside the main transformer, as well as the type, severity, and development trend of the fault. Currently, instruments for detecting dissolved gases in the insulating oil inside the main transformer are divided into two types: offline detection instruments and online monitoring devices. Offline detection instruments mainly use offline chromatographs and offline spectrometers for detection. The advantages are high detection accuracy and stable and reliable equipment. The disadvantages are that manual sampling is required at the substation main transformer, and the samples are then taken back to the laboratory for detection and analysis using the above offline detection instruments. Typically, testing is conducted every three months. For the detection of the large number of substation main transformers in the power system, this requires a lot of manpower, material resources, and time. Moreover, the test data from offline detection instruments is seriously delayed, especially when a sudden accident occurs in the main transformer, making timely detection impossible and affecting the safe operation of the main transformer.

[0004] In actual operation, the online monitoring device for dissolved gases in insulating oil is installed near the main transformer in the substation. Its sampling tube is directly connected to the inside of the main transformer. The advantage is that it can automatically test every day, and can detect internal faults in the main transformer in a timely manner, saving a lot of manpower and material resources. The disadvantage is that the detection accuracy is relatively low, and the stability and reliability are not as good as offline testing instruments. Online monitoring devices for dissolved gases in insulating oil are mainly divided into online chromatographic monitoring devices, selective characteristic gas sensor detectors, and online spectral monitoring devices. In the field of dissolved gas detection in insulating oil, online monitoring is the development direction. Through technological progress and continuous improvement of product quality, it is expected to replace offline testing instruments in the future. However, at present, the product quality of some manufacturers is not up to standard. It may be okay in the initial use, but the degradation rate is very fast. After a period of use, various problems often occur, resulting in inaccurate test data, poor equipment stability, and affecting the safe operation of the main transformer.

[0005] Among the aforementioned operational issues, the online chromatographic monitoring device of the dissolved gas monitoring device in insulating oil mainly exhibits accelerated degradation in the adsorption material, thermal conductivity detector, sampling and degassing unit within the chromatographic column, as the number of detections and the concentration of fault characteristic gas increase. Similarly, for the online characteristic gas sensor detector and the online spectral monitoring device, the sampling and degassing unit, sensing unit, and spectral detection unit will also age faster with the increase in the number of detections and the concentration of fault characteristic gas.

[0006] If a testing platform and testing method can be invented to quickly verify the degradation of existing online monitoring devices for dissolved gases in insulating oil, and to screen out excellent online monitoring devices for dissolved gases in insulating oil, it will be of great significance to ensuring the safe operation of main transformers.

[0007] This invention proposes a solution to the above problems. Summary of the Invention

[0008] This invention proposes a device for accelerated degradation detection of online dissolved gas monitoring devices in insulating oil. It can perform accelerated degradation treatment on online dissolved gas monitoring devices in insulating oil and evaluate the operational reliability of such devices based on the performance of the tested devices during and after the treatment.

[0009] The present invention adopts the following technical solution.

[0010] The device is used for accelerated degradation detection of online monitoring devices for dissolved gases in insulating oil. It can perform accelerated degradation detection on online monitoring devices for dissolved gases in insulating oil. The device includes a control module, a characteristic gas component saturated dissolution tank (1), and multiple oil sample cylinders containing oil samples (24) of known standard concentration mixed components. The characteristic gas component saturated dissolution tank is used to simulate transformer equipment containing insulating oil. It is connected to the online monitoring device (10) for dissolved gases in insulating oil to be tested via a solenoid valve. The characteristic gas component saturated dissolution tank contains pre-prepared insulating oil with a saturated concentration of characteristic gas components, i.e., according to... The insulating oil sample (2) is prepared with a saturated concentration of single-component or multi-component characteristic gas or interfering component to be detected. Under the control of the control module, the online monitoring device for dissolved gases in the insulating oil performs high-frequency and high-intensity detection of characteristic gas components with saturated concentration in the oil sample of the characteristic gas component saturated dissolution tank, so as to accelerate the degradation of the online monitoring device for dissolved gases in the insulating oil. After the degradation is completed, the oil sample cylinder is tested again. The control module evaluates the quality of the online monitoring device for dissolved gases in the insulating oil based on the operating condition data of the online monitoring device for dissolved gases in the insulating oil during the accelerated degradation process and after degradation.

[0011] The online monitoring device for dissolved gases in the insulating oil to be tested is connected to multiple oil sample cylinders containing mixed component oil samples (24) with known standard concentrations. The oil sample cylinders include standard high-concentration characteristic gas component oil sample cylinders (11), standard medium-concentration characteristic gas component oil sample cylinders (12), and standard low-concentration characteristic gas component oil sample cylinders (13) connected together.

[0012] The standard high-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing standard known high-concentration characteristic gas components;

[0013] The standard medium-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing a standard medium-concentration characteristic gas component;

[0014] The standard low-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing standard known low-concentration characteristic gas components;

[0015] The online monitoring device for dissolved gases in the insulating oil to be tested is connected to a multi-channel switching valve.

[0016] A flexible corrugated expansion joint (6) is vertically installed at the top center of the characteristic gas component saturated dissolution tank to balance and compensate for changes in the tank pressure. When the pressure inside the tank increases, the flexible corrugated expansion joint stretches and expands. When the pressure inside the tank decreases, the flexible corrugated expansion joint contracts. When the equipment performs a detection operation, the saturated concentration insulating oil sample in the characteristic gas component saturated dissolution tank is consumed by the detection operation, causing the flexible corrugated expansion joint to retract to the lowest position. At this time, saturated concentration insulating oil sample is added to the tank.

[0017] The top of the characteristic gas component saturated dissolution tank is also equipped with a first solenoid valve (5) for injecting the prepared saturated concentration characteristic gas component oil sample into the tank; the saturated concentration characteristic gas component oil sample is a single-component or multi-component mixed saturated concentration characteristic gas component oil sample.

[0018] The bottom of the saturated dissolution tank for the characteristic gas components is equipped with a stirrer; the stirrer is a magnetic stirrer or a circulating pump; the magnetic stirrer includes a magnetic stirring rod (3) wrapped in PTFE material inside the tank.

[0019] A second solenoid valve (7) is provided on the lower side wall of the saturated dissolution tank for the characteristic gas components; the second solenoid valve is connected to the second channel of the multi-channel switching valve.

[0020] When conducting accelerated degradation testing on the online dissolved gas monitoring device in the insulating oil to be tested, the second solenoid valve of the characteristic gas component saturated dissolution tank is opened, allowing the saturated concentration of characteristic gas component oil sample in the dissolution tank to enter the online dissolved gas monitoring device in the insulating oil to be tested. The online dissolved gas monitoring device in the insulating oil is subjected to accelerated degradation testing. This is achieved by conducting an intensive test every 60 minutes, with each test using the insulating oil at the highest dissolved concentration of the characteristic gas component at saturation for 240 consecutive hours, or by conducting an intensive test according to the limit test requirements that the main transformer online monitoring device can withstand, in order to accelerate the degradation rate of the online dissolved gas monitoring device in the insulating oil to expose its existing internal hidden dangers and defects.

[0021] The accelerated degradation detection also includes a process for assessing the degradation rate of the online dissolved gas monitoring device in insulating oil. This involves subjecting the device to a period of time to intensive testing with high-frequency, highest-concentration (saturated dissolved gas concentration) characteristic gases in the insulating oil. Then, the device is switched to test pre-prepared mixed insulating oil samples containing standard known high-concentration characteristic gas components, standard known medium-concentration characteristic gas components, and standard known low-concentration characteristic gas components. The degradation rate of the online dissolved gas monitoring device is assessed based on its accuracy, precision, and linearity. If the detection data of the online dissolved gas monitoring device for the above high, medium, and low standard known concentration characteristic gas component mixed insulating oil samples exceeds the calibrated values ​​and linearity limits, or if the detection precision does not meet the requirements, the device is considered degraded and needs to be recalibrated or replaced.

[0022] The oil sample cylinder includes a vertical cylindrical body (20), a piston (21), a miniature solenoid valve (23), and a micro-elastic spring (22). The vertical cylindrical body and the piston are both made of PTFE material and are combined into a cylindrical piston matching structure similar to that of a medical syringe.

[0023] The miniature solenoid valve is installed at the center of the bottom of the vertical cylinder, the piston is inserted into the vertical cylinder through the upper part of the opening of the vertical cylinder and can slide inside the vertical cylinder; the micro-elastic spring is installed and fixed at both ends of the top of the oil sample cylinder;

[0024] When storing oil samples in the oil sample cylinder, a pre-prepared mixed component oil sample of known standard concentration is injected into the piston oil sample cylinder without air bubbles through a micro solenoid valve, and an oil film seal is formed between the outer wall of the piston and the inner wall of the vertical cylinder. The micro elastic spring maintains a clamping force between the piston and the vertical cylinder to prevent the leakage of gas dissolved in the standard concentration component oil sample, so as to ensure the accuracy of the standard concentration component oil sample.

[0025] A high-concentration micro solenoid valve is installed at the bottom of the standard high-concentration characteristic gas component oil sample cylinder, a medium-concentration micro solenoid valve is installed at the bottom of the standard medium-concentration characteristic gas component oil sample cylinder, and a low-concentration micro solenoid valve is installed at the bottom of the standard low-concentration characteristic gas component oil sample cylinder.

[0026] A high-concentration miniature solenoid valve is connected via a pipeline to the fourth channel of the multi-channel switching valve of the online dissolved gas monitoring device for the insulating oil under test; a medium-concentration miniature solenoid valve is connected via a pipeline to the fifth channel of the same device; and a low-concentration miniature solenoid valve is connected via a pipeline to the sixth channel. The oil sample cylinders containing the above standard high, medium, and low concentration characteristic gas components are pre-filled with standard high, medium, and low concentration characteristic gas component oil samples of known concentrations.

[0027] The control module controls the online dissolved gas monitoring device in the insulating oil to detect these three oil samples with different known concentrations of characteristic gas components, in order to evaluate the accuracy, detection precision and linearity of the online dissolved gas monitoring device in the insulating oil, thereby inferring the degradation status of the online dissolved gas monitoring device in the insulating oil.

[0028] The multi-channel switching valve of the online monitoring device for dissolved gases in the insulating oil to be tested is a six-way switching valve (9); the online monitoring device for dissolved gases in the insulating oil is an online chromatographic monitoring device, a selective characteristic gas sensor detector, or an online spectral monitoring device;

[0029] The second channel (15) of the six-way switching valve is connected to the second solenoid valve of the characteristic gas component saturated dissolution tank, and the first channel (14) of the six-way switching valve is connected to the external discharge port. A collection tank (8) is placed under the external discharge port. The collection tank is used to collect the discharged insulating oil for centralized treatment.

[0030] The fourth channel (17) of the six-way switching valve is connected to the high-concentration micro solenoid valve, the fifth channel (18) of the six-way switching valve is connected to the medium-concentration micro solenoid valve, the sixth channel (19) of the six-way switching valve is connected to the low-concentration micro solenoid valve, and the third channel (16) of the six-way switching valve is used as a spare channel or a transfer channel.

[0031] During accelerated degradation detection, the online monitoring device for dissolved gases in insulating oil detects the content of each component of the mixed characteristic gases contained in the insulating oil sample and transmits the detection data to the control module in real time.

[0032] The multi-channel switching valve of the online monitoring device for dissolved gases in the insulating oil to be tested is a six-way switching valve; the control module is also connected to the alarm, and the control module is pre-set with a control program for accelerating degradation detection, specifically including:

[0033] A1. A program that controls the main transformer online equipment to automatically detect the concentration of characteristic gas components in the saturated dissolution tank every 60 minutes;

[0034] A2. The program for automatically detecting standard high, medium and low known concentration characteristic gas components in oil samples of insulating oil by switching the online monitoring device for dissolved gas in the insulating oil at 240-hour intervals. When this program is executed, the automatic detection of the characteristic gas concentration of saturated components in the saturated dissolution tank of characteristic gas components is stopped.

[0035] A3. Automatic alarm setting program for the online monitoring device for dissolved gases in insulating oil under test, detecting high, medium and low concentration characteristic gas components in oil samples, and setting the accuracy deviation range of the oil sample;

[0036] A4. Automatic alarm setting program for the linear fit deviation range of oil sample in high, medium and low concentration characteristic gas components of the online monitoring device for dissolved gases in insulating oil;

[0037] The input terminal of the control module is electrically connected to the data output terminal of the online dissolved gas monitoring device in the insulating oil to be tested and the output terminal of the external time relay, respectively. The output terminal of the control module is electrically connected to the six-way switching valve of the online dissolved gas monitoring device in the insulating oil to be tested, the first solenoid valve and the second solenoid valve of the characteristic gas component saturated dissolution tank, the magnetic stirrer of the characteristic gas component saturated dissolution tank, the high-concentration miniature solenoid valve of the standard high-concentration characteristic gas component oil sample cylinder, the medium-concentration miniature solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder, the low-concentration miniature solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder, and the input terminal of the alarm.

[0038] The accelerated degradation detection includes the following detection items;

[0039] Project A involves using an online dissolved gas monitoring device to perform high-volume testing on saturated insulating oil containing characteristic gas components, in order to accelerate its aging process.

[0040] Project B involves using an online monitoring device to control dissolved gases in accelerated aging insulating oil. This device compares and tests standard oil samples containing known concentrations of characteristic gases of high, medium, and low components within the oil sample cylinder to evaluate the device's performance after aging.

[0041] Project A includes the following steps;

[0042] Step A1: Add the prepared characteristic gas component saturated solution insulating oil sample to the characteristic gas component saturated dissolution tank through the first solenoid valve, and close the first solenoid valve after filling.

[0043] Step A2: The flexible corrugated expansion joint installed on the top of the characteristic gas component saturated dissolution tank is used to balance and compensate for the pressure change inside the saturated dissolution tank. When the pressure inside the dissolution tank increases, the corrugated expansion joint stretches and expands, and conversely, it contracts and descends. When the saturated concentration insulating oil sample inside the characteristic gas component saturated dissolution tank is consumed by the detection process, causing the flexible corrugated expansion joint to retract to the lowest position, the saturated concentration insulating oil sample is added to the tank.

[0044] Step A3: Turn on the magnetic stirrer in the dissolving tank (4);

[0045] Step A4: Open the second solenoid valve of the dissolving tank;

[0046] Step A5: Turn on the online monitoring device for dissolved gas in the insulating oil to be tested;

[0047] Step A6: After the online monitoring device for dissolved gas in the tested insulating oil is running stably, switch the operating condition of the six-way switching valve to the first channel of the six-way switching valve to connect to the second solenoid valve of the saturated dissolving tank, use a small amount of saturated solution insulating oil sample in the dissolving tank to flush the pipeline, and discharge the flushing oil into the collection tank (8) through the external discharge port of the first channel of the six-way valve.

[0048] Step A7: After rinsing, switch the operating condition of the six-way switching valve to the second channel (15) of the six-way switching valve and connect it to the second solenoid valve of the saturated dissolving tank. After the saturated solution insulating oil sample in the dissolving tank is quantitatively extracted by the online monitoring device for dissolved gas in the insulating oil being tested, close the second solenoid valve and close the magnetic stirrer.

[0049] Step A8: During the detection process, the gas or liquid sample released from the saturated solution insulating oil sample is detected by the adsorption column, detector or sensing unit of the online monitoring device for dissolved gases in the insulating oil being tested.

[0050] Step A9: After the online monitoring device for dissolved gases in the tested insulating oil has completed its detection, it should be automatically shut down.

[0051] Step A10: After the time since the last test reaches the set 60-minute interval, the same work of steps A4 to A9 will be automatically repeated until 240 hours, so as to accelerate the aging of the online monitoring device for dissolved gas in the tested insulating oil.

[0052] Step A11: In the above steps, the online monitoring device for dissolved gases in the insulating oil being tested transmits the detection data to the control module in real time. When the deviation of the detection data exceeds the set value, the control module controls the alarm to sound.

[0053] Project B includes the following steps;

[0054] Step B1: The online monitoring device for dissolved gases in the insulating oil under test performs accelerated aging treatment by testing the saturated solution insulating oil sample. After the aging treatment time reaches 240 hours, the online monitoring device for dissolved gases in the insulating oil under test is turned on, and the solenoid valve of the first channel (14) of the six-way switching valve is connected to the standard low concentration characteristic gas component oil sample cylinder (13).

[0055] Step B2: Open the solenoid valve of the standard low concentration characteristic gas component oil sample cylinder, first use a small amount of low concentration standard mixed oil sample in the standard low concentration characteristic gas component oil sample cylinder to flush the pipeline, and discharge the flushing oil to the collection tank (8) through the external discharge port of the first channel (14) of the six-way switching valve.

[0056] Step B3: Switch the sixth channel (19) of the six-way switching valve to be connected to the solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder. After the online monitoring device for dissolved gas in the tested insulating oil quantitatively extracts the known standard low-concentration insulating oil in the standard low-concentration characteristic gas component oil sample cylinder, it closes the miniature solenoid valve of the oil sample cylinder.

[0057] Step B4: At this point, the gas or liquid sample containing a known low concentration of dissolved gas from the insulating oil is quantitatively detected by the adsorption column, detector, or sensor of the online monitoring device for dissolved gases in the insulating oil being tested, and the detection data is transmitted to the control module in real time.

[0058] Step B5: After the online monitoring device for dissolved gases in the insulating oil under test has completed the test on the insulating oil sample containing a known low concentration, the solenoid valve of the first channel (14) of the six-way switching valve is switched to connect with the solenoid valve of the standard medium concentration characteristic gas component oil sample cylinder (12).

[0059] Step B6: Open the solenoid valve of the standard medium concentration characteristic gas component oil sample cylinder (12), first flush the pipeline with a small amount of known medium concentration standard mixed oil sample, and discharge the flushing oil to the collection tank through the external discharge port of the first channel of the six-way switching valve.

[0060] Step B7: Switch the second channel (15) of the six-way switching valve to the solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder (12). After the online monitoring device for dissolved gas in insulating oil quantitatively extracts the known medium-concentration insulating oil in the standard medium-concentration characteristic gas component oil sample cylinder (12), close the miniature solenoid valve of the oil sample cylinder.

[0061] Step B8: At this point, the gas or liquid sample containing a known medium concentration of dissolved gas from the insulating oil is quantitatively detected by the adsorption column, detector, or sensor of the online monitoring device for dissolved gases in the insulating oil being tested, and the detection data is transmitted to the control module in real time.

[0062] Step B9: Similar to the above steps, the online monitoring device for dissolved gases in the insulating oil under test detects and transmits the detection data of the known high-concentration characteristic gas component oil sample in the standard high-concentration characteristic gas component oil sample cylinder (11).

[0063] Step B10: If the accuracy, precision, and linearity of the detection data of the online monitoring device for dissolved gases in the insulating oil exceed the set range for the three different known concentrations of characteristic gas components in the oil sample, the alarm will sound, indicating to the staff that the online monitoring device for dissolved gases in the insulating oil can no longer meet the performance requirements after accelerated degradation treatment and is not suitable for practical use.

[0064] The advantages of this invention are as follows:

[0065] 1) The detection equipment described in this invention can automatically use characteristic gas components to saturate the insulating oil sample, thereby accelerating the degradation process of the online monitoring device for dissolved gases in the insulating oil;

[0066] 2) This invention includes a standard insulating oil sample comparison test device containing high, medium and low known component concentrations, which can meet the requirements for inspecting the degree of degradation after the online monitoring device for dissolved gases in insulating oil undergoes accelerated degradation test;

[0067] 3) The device described in this invention can operate for a long time to perform accelerated degradation detection of the online monitoring device for dissolved gases in insulating oil.

[0068] This invention is the first of its kind in the field of online monitoring devices for large power transformers. By conducting a high-frequency intensive test for 240 hours using an insulating oil sample with the highest concentration of characteristic gas components (saturated concentration) every 60 minutes, the degradation rate of the online monitoring device for dissolved gases in insulating oil can be greatly accelerated. In particular, it can quickly expose the existing hidden dangers and quality defects in the online monitoring device for dissolved gases in insulating oil, thereby achieving the purpose of screening and evaluating power grid equipment.

[0069] This invention can assess the degradation rate of online dissolved gas monitoring devices in insulating oil. It involves periodically conducting enhanced testing of the device with high-frequency, highest-concentration characteristic gases in the insulating oil, followed by testing of pre-prepared mixed insulating oil samples containing standard high-concentration, medium-concentration, and low-concentration characteristic gas components. The accuracy, precision, and linearity of the detection are then evaluated to effectively reflect the degradation rate of dissolved gases in the insulating oil. The degradation status of the online gas dissolved gas monitoring device is assessed. When the detection data of the online gas dissolved gas monitoring device for the mixed insulating oil sample with high, medium, and low standard concentrations of characteristic gas components do not meet the requirements of the calibrated values ​​and linear ratios, or when the detection accuracy exceeds the allowable error, it is considered that the online gas dissolved gas monitoring device for the insulating oil has degraded and needs to be recalibrated or replaced. Conversely, the same applies. In this way, substandard online gas dissolved gas monitoring devices for insulating oil can be identified in a short time, and high-quality and qualified products can be selected, effectively ensuring the safe operation of the main transformer. Attached Figure Description

[0070] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0071] Appendix Figure 1 This is a schematic diagram of the detection platform layout according to the present invention;

[0072] Appendix Figure 2 This is a schematic diagram of the operation of the solution described in this invention;

[0073] Appendix Figure 3 This is a schematic diagram of the structure and operation of the oil sample cylinder according to the present invention;

[0074] Appendix Figure 4 This is a schematic diagram of each channel of the six-way switching valve according to the present invention;

[0075] Appendix Figure 5 This is a block diagram illustrating the control principle of the control module of the solution described in this invention;

[0076] In the diagram: 1-Saturated dissolution vessel for characteristic gas components; 2-Saturated concentration insulating oil sample; 3-Magnetic stirring rod; 4-Magnetic stirrer; 5-First solenoid valve; 6-Flexible corrugated expansion joint; 7-Second solenoid valve; 8-Collection tank; 9-Six-way switching valve;

[0077] 10-Online monitoring device for dissolved gases in insulating oil; 11-Standard high-concentration characteristic gas component oil sample cylinder; 12-Standard medium-concentration characteristic gas component oil sample cylinder; 13-Standard low-concentration characteristic gas component oil sample cylinder; 14-First channel; 15-Second channel; 16-Third channel; 17-Fourth channel; 18-Fifth channel; 19-Sixth channel;

[0078] 20 - Vertical cylindrical body; 21 - Piston; 22 - Micro-elastic spring; 23 - Miniature solenoid valve; 24 - Oil sample of mixed components with known standard concentration. Detailed Implementation

[0079] As shown in the figure, the equipment for accelerated degradation detection of the online monitoring device for dissolved gases in insulating oil can perform accelerated degradation detection on the online monitoring device for dissolved gases in insulating oil. The equipment includes a control module, a characteristic gas component saturated dissolution tank 1, and multiple oil sample cylinders storing oil samples 24 with known standard concentrations of mixed components. The characteristic gas component saturated dissolution tank is used to simulate transformer equipment containing insulating oil. It is connected to the online monitoring device 10 for dissolved gases in insulating oil to be tested via a solenoid valve. The characteristic gas component saturated dissolution tank contains pre-prepared insulating oil with saturated concentrations of characteristic gas components. The insulating oil sample 2 is prepared according to the saturated concentration of single-component or multi-component characteristic gas or interfering component as required for detection; under the control of the control module, the online dissolved gas monitoring device in the insulating oil performs high-frequency and high-intensity detection of characteristic gas components in the oil sample of the characteristic gas component saturated dissolution tank, so as to accelerate the degradation of the online dissolved gas monitoring device in the insulating oil, and after the degradation is completed, the oil sample cylinder is tested again. The control module evaluates the quality of the online dissolved gas monitoring device in the insulating oil based on the operating condition data of the online dissolved gas monitoring device in the insulating oil during the accelerated degradation process and after degradation.

[0080] The online monitoring device for dissolved gases in the insulating oil to be tested is connected to multiple oil sample cylinders containing mixed components of known standard concentrations 24. The oil sample cylinders include standard high-concentration characteristic gas component oil sample cylinder 11, standard medium-concentration characteristic gas component oil sample cylinder 12, and standard low-concentration characteristic gas component oil sample cylinder 13.

[0081] The standard high-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing standard known high-concentration characteristic gas components;

[0082] The standard medium-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing a standard medium-concentration characteristic gas component;

[0083] The standard low-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing standard known low-concentration characteristic gas components;

[0084] The online monitoring device for dissolved gases in the insulating oil to be tested is connected to a multi-channel switching valve.

[0085] A flexible corrugated expansion joint 6 is vertically installed at the top center of the characteristic gas component saturated dissolution tank to balance and compensate for changes in the tank pressure. When the pressure inside the tank increases, the flexible corrugated expansion joint stretches and expands; when the pressure inside the tank decreases, the flexible corrugated expansion joint contracts. When the equipment performs a detection operation, the saturated concentration insulating oil sample in the characteristic gas component saturated dissolution tank is consumed by the detection operation, causing the flexible corrugated expansion joint to retract to its lowest position, and then the saturated concentration insulating oil sample is added back into the tank.

[0086] The top of the characteristic gas component saturated dissolution tank is also equipped with a first solenoid valve 5 for injecting the prepared saturated concentration characteristic gas component oil sample into the tank; the saturated concentration characteristic gas component oil sample is a single-component or multi-component mixed saturated concentration characteristic gas component oil sample.

[0087] The bottom of the saturated dissolution tank for the characteristic gas components is equipped with a stirrer; the stirrer is a magnetic stirrer or a circulating pump; the magnetic stirrer includes a magnetic stirring rod 3 wrapped with PTFE material inside the tank;

[0088] A second solenoid valve 7 is provided on the lower side wall of the saturated dissolution tank for the characteristic gas components; the second solenoid valve is connected to the second channel of the multi-channel switching valve.

[0089] When conducting accelerated degradation testing on the online dissolved gas monitoring device in the insulating oil to be tested, the second solenoid valve of the characteristic gas component saturated dissolution tank is opened, allowing the saturated concentration of characteristic gas component oil sample in the dissolution tank to enter the online dissolved gas monitoring device in the insulating oil to be tested. The online dissolved gas monitoring device in the insulating oil is subjected to accelerated degradation testing. This is achieved by conducting an intensive test every 60 minutes, with each test using the insulating oil at the highest dissolved concentration of the characteristic gas component at saturation for 240 consecutive hours, or by conducting an intensive test according to the limit test requirements that the main transformer online monitoring device can withstand, in order to accelerate the degradation rate of the online dissolved gas monitoring device in the insulating oil to expose its existing internal hidden dangers and defects.

[0090] The accelerated degradation detection also includes a process for assessing the degradation rate of the online dissolved gas monitoring device in insulating oil. This involves subjecting the device to a period of time to intensive testing with high-frequency, highest-concentration (saturated dissolved gas concentration) characteristic gases in the insulating oil. Then, the device is switched to test pre-prepared mixed insulating oil samples containing standard known high-concentration characteristic gas components, standard known medium-concentration characteristic gas components, and standard known low-concentration characteristic gas components. The degradation rate of the online dissolved gas monitoring device is assessed based on its accuracy, precision, and linearity. If the detection data of the online dissolved gas monitoring device for the above high, medium, and low standard known concentration characteristic gas component mixed insulating oil samples exceeds the calibrated values ​​and linearity limits, or if the detection precision does not meet the requirements, the device is considered degraded and needs to be recalibrated or replaced.

[0091] The oil sample cylinder includes a vertical cylindrical body 20, a piston 21, a miniature solenoid valve 23, and a micro-elastic spring 22. The vertical cylindrical body and the piston are both made of PTFE material and are combined into a cylindrical piston matching structure similar to that of a medical syringe.

[0092] The miniature solenoid valve is installed at the center of the bottom of the vertical cylinder, the piston is inserted into the vertical cylinder through the upper part of the opening of the vertical cylinder and can slide inside the vertical cylinder; the micro-elastic spring is installed and fixed at both ends of the top of the oil sample cylinder;

[0093] When storing oil samples in the oil sample cylinder, a pre-prepared mixed component oil sample of known standard concentration is injected into the piston oil sample cylinder without air bubbles through a micro solenoid valve, and an oil film seal is formed between the outer wall of the piston and the inner wall of the vertical cylinder. The micro elastic spring maintains a clamping force between the piston and the vertical cylinder to prevent the leakage of gas dissolved in the standard concentration component oil sample, so as to ensure the accuracy of the standard concentration component oil sample.

[0094] A high-concentration micro solenoid valve is installed at the bottom of the standard high-concentration characteristic gas component oil sample cylinder, a medium-concentration micro solenoid valve is installed at the bottom of the standard medium-concentration characteristic gas component oil sample cylinder, and a low-concentration micro solenoid valve is installed at the bottom of the standard low-concentration characteristic gas component oil sample cylinder.

[0095] A high-concentration miniature solenoid valve is connected via a pipeline to the fourth channel of the multi-channel switching valve of the online dissolved gas monitoring device for the insulating oil under test; a medium-concentration miniature solenoid valve is connected via a pipeline to the fifth channel of the same device; and a low-concentration miniature solenoid valve is connected via a pipeline to the sixth channel. The oil sample cylinders containing the above standard high, medium, and low concentration characteristic gas components are pre-filled with standard high, medium, and low concentration characteristic gas component oil samples of known concentrations.

[0096] The control module controls the online dissolved gas monitoring device in the insulating oil to detect these three oil samples with different known concentrations of characteristic gas components, in order to evaluate the accuracy, detection precision and linearity of the online dissolved gas monitoring device in the insulating oil, thereby inferring the degradation status of the online dissolved gas monitoring device in the insulating oil.

[0097] The multi-channel switching valve of the online monitoring device for dissolved gases in the insulating oil to be tested is a six-way switching valve 9; the online monitoring device for dissolved gases in the insulating oil is an online chromatographic monitoring device, a selective characteristic gas sensor detector, or an online spectral monitoring device;

[0098] The second channel 15 of the six-way switching valve is connected to the second solenoid valve of the characteristic gas component saturated dissolution tank, and the first channel 14 of the six-way switching valve is connected to the external discharge port. A collection tank 8 is placed under the external discharge port. The collection tank is used to collect the discharged insulating oil for centralized treatment.

[0099] The fourth channel 17 of the six-way switching valve is connected to the high-concentration miniature solenoid valve, the fifth channel 18 of the six-way switching valve is connected to the medium-concentration miniature solenoid valve, the sixth channel 19 of the six-way switching valve is connected to the low-concentration miniature solenoid valve, and the third channel 16 of the six-way switching valve is used as a spare channel or a transfer channel.

[0100] During accelerated degradation detection, the online monitoring device for dissolved gases in insulating oil detects the content of each component of the mixed characteristic gases contained in the insulating oil sample and transmits the detection data to the control module in real time.

[0101] The multi-channel switching valve of the online monitoring device for dissolved gases in the insulating oil to be tested is a six-way switching valve; the control module is also connected to the alarm, and the control module is pre-set with a control program for accelerating degradation detection, specifically including:

[0102] A1. A program that controls the main transformer online equipment to automatically detect the concentration of characteristic gas components in the saturated dissolution tank every 60 minutes;

[0103] A2. The program for automatically detecting standard high, medium and low known concentration characteristic gas components in oil samples of insulating oil by switching the online monitoring device for dissolved gas in the insulating oil at 240-hour intervals. When this program is executed, the automatic detection of the characteristic gas concentration of saturated components in the saturated dissolution tank of characteristic gas components is stopped.

[0104] A3. Automatic alarm setting program for the online monitoring device for dissolved gases in insulating oil under test, detecting high, medium and low concentration characteristic gas components in oil samples, and setting the accuracy deviation range of the oil sample;

[0105] A4. Automatic alarm setting program for the linear fit deviation range of oil sample in high, medium and low concentration characteristic gas components of the online monitoring device for dissolved gases in insulating oil;

[0106] The input terminal of the control module is electrically connected to the data output terminal of the online dissolved gas monitoring device in the insulating oil to be tested and the output terminal of the external time relay, respectively. The output terminal of the control module is electrically connected to the six-way switching valve of the online dissolved gas monitoring device in the insulating oil to be tested, the first solenoid valve and the second solenoid valve of the characteristic gas component saturated dissolution tank, the magnetic stirrer of the characteristic gas component saturated dissolution tank, the high-concentration miniature solenoid valve of the standard high-concentration characteristic gas component oil sample cylinder, the medium-concentration miniature solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder, the low-concentration miniature solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder, and the input terminal of the alarm.

[0107] The accelerated degradation detection includes the following detection items;

[0108] Project A involves using an online dissolved gas monitoring device to perform high-volume testing on saturated insulating oil containing characteristic gas components, in order to accelerate its aging process.

[0109] Project B involves using an online monitoring device to control dissolved gases in accelerated aging insulating oil. This device compares and tests standard oil samples containing known concentrations of characteristic gases of high, medium, and low components within the oil sample cylinder to evaluate the device's performance after aging.

[0110] Project A includes the following steps;

[0111] Step A1: Add the prepared characteristic gas component saturated solution insulating oil sample to the characteristic gas component saturated dissolution tank through the first solenoid valve, and close the first solenoid valve after filling.

[0112] Step A2: The flexible corrugated expansion joint installed on the top of the characteristic gas component saturated dissolution tank is used to balance and compensate for the pressure change inside the saturated dissolution tank. When the pressure inside the dissolution tank increases, the corrugated expansion joint stretches and expands, and conversely, it contracts and descends. When the saturated concentration insulating oil sample inside the characteristic gas component saturated dissolution tank is consumed by the detection process, causing the flexible corrugated expansion joint to retract to the lowest position, the saturated concentration insulating oil sample is added to the tank.

[0113] Step A3: Turn on the magnetic stirrer 4 of the dissolving tank;

[0114] Step A4: Open the second solenoid valve of the dissolving tank;

[0115] Step A5: Turn on the online monitoring device for dissolved gas in the insulating oil to be tested;

[0116] Step A6: After the online monitoring device for dissolved gas in the tested insulating oil has been running stably, switch the operating mode of the six-way switching valve to the first channel of the six-way switching valve to connect to the second solenoid valve of the saturated dissolving tank. Use a small amount of saturated solution insulating oil sample from the dissolving tank to flush the pipeline, and discharge the flushing oil into the collection tank 8 through the external discharge port of the first channel of the six-way valve.

[0117] Step A7: After rinsing, switch the six-way switching valve to the second channel 15 of the six-way switching valve to connect to the second solenoid valve of the saturated dissolving tank. After the saturated solution insulating oil sample in the dissolving tank is quantitatively extracted by the online monitoring device for dissolved gas in the insulating oil being tested, close the second solenoid valve and turn off the magnetic stirrer.

[0118] Step A8: During the detection process, the gas or liquid sample released from the saturated solution insulating oil sample is detected by the adsorption column, detector or sensing unit of the online monitoring device for dissolved gases in the insulating oil being tested.

[0119] Step A9: After the online monitoring device for dissolved gases in the tested insulating oil has completed its detection, it should be automatically shut down.

[0120] Step A10: After the time since the last test reaches the set 60-minute interval, the same work of steps A4 to A9 will be automatically repeated until 240 hours, so as to accelerate the aging of the online monitoring device for dissolved gas in the tested insulating oil.

[0121] Step A11: In the above steps, the online monitoring device for dissolved gases in the insulating oil being tested transmits the detection data to the control module in real time. When the deviation of the detection data exceeds the set value, the control module controls the alarm to sound.

[0122] Project B includes the following steps;

[0123] Step B1: The online monitoring device for dissolved gases in the insulating oil under test performs accelerated aging treatment by testing the saturated solution insulating oil sample. After the aging treatment time reaches 240 hours, the online monitoring device for dissolved gases in the insulating oil under test is turned on, and the solenoid valve of the first channel 14 of the six-way switching valve is connected to the standard low concentration characteristic gas component oil sample cylinder 13.

[0124] Step B2: Open the solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder, first use a small amount of low-concentration standard mixed oil sample in the standard low-concentration characteristic gas component oil sample cylinder to flush the pipeline, and discharge the flushing oil to the collection tank 8 through the external discharge port of the first channel 14 of the six-way switching valve.

[0125] Step B3: Switch the sixth channel 19 of the six-way switching valve to the solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder. After the online monitoring device for dissolved gas in the tested insulating oil quantitatively extracts the known standard low-concentration insulating oil in the standard low-concentration characteristic gas component oil sample cylinder, close the miniature solenoid valve of the oil sample cylinder.

[0126] Step B4: At this point, the gas or liquid sample containing a known low concentration of dissolved gas from the insulating oil is quantitatively detected by the adsorption column, detector, or sensor of the online monitoring device for dissolved gases in the insulating oil being tested, and the detection data is transmitted to the control module in real time.

[0127] Step B5: After the online monitoring device for dissolved gases in the tested insulating oil has completed the test on the insulating oil sample containing a known low concentration, the solenoid valve of the first channel 14 of the six-way switching valve is switched to connect with the solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder 12.

[0128] Step B6: Open the solenoid valve of the standard medium concentration characteristic gas component oil sample cylinder 12, first flush the pipeline with a small amount of known medium concentration standard mixed oil sample, and discharge the flushing oil to the collection tank through the external discharge port of the first channel of the six-way switching valve.

[0129] Step B7: Switch the second channel 15 of the six-way switching valve to the solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder 12. After the online monitoring device for dissolved gas in insulating oil quantitatively extracts the known medium-concentration insulating oil in the standard medium-concentration characteristic gas component oil sample cylinder 12, close the miniature solenoid valve of the oil sample cylinder.

[0130] Step B8: At this point, the gas or liquid sample containing a known medium concentration of dissolved gas from the insulating oil is quantitatively detected by the adsorption column, detector, or sensor of the online monitoring device for dissolved gases in the insulating oil being tested, and the detection data is transmitted to the control module in real time.

[0131] Step B9: Similar to the above steps, the online monitoring device for dissolved gases in the insulating oil under test detects and transmits the detection data of the known high-concentration characteristic gas component oil sample in the standard high-concentration characteristic gas component oil sample cylinder 11.

[0132] Step B10: If the accuracy, precision, and linearity of the detection data of the online monitoring device for dissolved gases in the insulating oil exceed the set range for the three different known concentrations of characteristic gas components in the oil sample, the alarm will sound, indicating to the staff that the online monitoring device for dissolved gases in the insulating oil can no longer meet the performance requirements after accelerated degradation treatment and is not suitable for practical use.

Claims

1. Equipment for accelerated degradation detection of online dissolved gas monitoring devices in insulating oil, characterized in that: The device includes a control module, a characteristic gas component saturated dissolution tank (1), and multiple oil sample cylinders containing mixed component oil samples (24) with known standard concentrations. The characteristic gas component saturated dissolution tank is used to simulate transformer equipment containing insulating oil. It is connected to the online monitoring device (10) for dissolved gases in the insulating oil to be tested via a solenoid valve. The characteristic gas component saturated dissolution tank contains pre-prepared insulating oil with saturated concentrations of characteristic gas components, i.e., saturated concentrations of single-component or multi-component characteristic gases or interfering components prepared according to the testing requirements (2). Under the control of the control module, the online monitoring device for dissolved gases in the insulating oil performs high-frequency and high-intensity saturated concentration component characteristic gas detection operations on the oil sample in the characteristic gas component saturated dissolution tank to accelerate the degradation of the online monitoring device for dissolved gases in the insulating oil. After degradation, the oil sample cylinder is tested. The control module evaluates the quality of the online monitoring device for dissolved gases in the insulating oil based on the operating data of the online monitoring device for dissolved gases in the insulating oil during the accelerated degradation process and after degradation. The online monitoring device for dissolved gases in the insulating oil to be tested is connected to multiple oil sample cylinders containing mixed component oil samples (24) with known standard concentrations. The oil sample cylinders include standard high-concentration characteristic gas component oil sample cylinders (11), standard medium-concentration characteristic gas component oil sample cylinders (12), and standard low-concentration characteristic gas component oil sample cylinders (13) connected together. The standard high-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing standard known high-concentration characteristic gas components; The standard medium-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing a standard medium-concentration characteristic gas component; The standard low-concentration characteristic gas component oil sample cylinder contains a mixed insulating oil sample containing standard known low-concentration characteristic gas components; The online monitoring device for dissolved gases in the insulating oil to be tested is connected to a multi-channel switching valve; a flexible corrugated expansion joint (6) for balancing and compensating for changes in pressure inside the tank is vertically installed at the top center of the characteristic gas component saturated dissolution tank. When the pressure inside the tank increases, the flexible corrugated expansion joint stretches and expands; when the pressure inside the tank decreases, the flexible corrugated expansion joint contracts. When the equipment performs a detection operation, the saturated concentration of insulating oil sample in the characteristic gas component saturated dissolution tank is consumed by the detection operation, causing the flexible corrugated expansion joint to retract to the lowest position, and then the saturated concentration of insulating oil sample is added to the tank. The top of the characteristic gas component saturated dissolution tank is also equipped with a first solenoid valve (5) for injecting the prepared saturated concentration characteristic gas component oil sample into the tank; the saturated concentration characteristic gas component oil sample is a single-component or multi-component mixed saturated concentration characteristic gas component oil sample. The bottom of the saturated dissolution tank for the characteristic gas components is equipped with a stirrer; the stirrer is a magnetic stirrer or a circulating pump; the magnetic stirrer includes a magnetic stirring rod (3) wrapped in PTFE material inside the tank.

2. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 1, characterized in that: A second solenoid valve (7) is provided on the lower side wall of the saturated dissolution tank for the characteristic gas components; the second solenoid valve is connected to the second channel of the multi-channel switching valve. When conducting accelerated degradation testing on the online dissolved gas monitoring device in the insulating oil to be tested, the second solenoid valve of the characteristic gas component saturated dissolution tank is opened, allowing the saturated concentration of characteristic gas component oil sample in the dissolution tank to enter the online dissolved gas monitoring device in the insulating oil to be tested. The online dissolved gas monitoring device in the insulating oil is subjected to accelerated degradation testing. This is achieved by conducting an intensive test every 60 minutes, with each test using the insulating oil at the highest dissolved concentration of the characteristic gas component at saturation for 240 consecutive hours, or by conducting an intensive test according to the limit test requirements that the main transformer online monitoring device can withstand, in order to accelerate the degradation rate of the online dissolved gas monitoring device in the insulating oil to expose its existing internal hidden dangers and defects. The accelerated degradation detection also includes a process for assessing the degradation rate of the online dissolved gas monitoring device in insulating oil. This involves subjecting the device to a period of time to intensive testing with high-frequency, highest-concentration (saturated dissolved gas concentration) characteristic gases in the insulating oil. Then, the device is switched to test pre-prepared mixed insulating oil samples containing standard known high-concentration characteristic gas components, standard known medium-concentration characteristic gas components, and standard known low-concentration characteristic gas components. The degradation rate of the online dissolved gas monitoring device is assessed based on its accuracy, precision, and linearity. If the detection data of the online dissolved gas monitoring device for the above high, medium, and low standard known concentration characteristic gas component mixed insulating oil samples exceeds the calibrated values ​​and linearity limits, or if the detection precision does not meet the requirements, the device is considered degraded and needs to be recalibrated or replaced.

3. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 1, characterized in that: The oil sample cylinder includes a vertical cylindrical body (20), a piston (21), a miniature solenoid valve (23), and a micro-elastic spring (22). The vertical cylindrical body and the piston are both made of PTFE material and are combined into a cylindrical piston matching structure similar to that of a medical syringe. The miniature solenoid valve is installed at the center of the bottom of the vertical cylinder, the piston is inserted into the vertical cylinder through the upper part of the opening of the vertical cylinder and can slide inside the vertical cylinder; the micro-elastic spring is installed and fixed at both ends of the top of the oil sample cylinder; When storing oil samples in the oil sample cylinder, a pre-prepared mixed component oil sample of known standard concentration is injected into the piston oil sample cylinder without air bubbles through a micro solenoid valve, and an oil film seal is formed between the outer wall of the piston and the inner wall of the vertical cylinder. The micro elastic spring maintains a clamping force between the piston and the vertical cylinder to prevent the leakage of gas dissolved in the standard concentration component oil sample, so as to ensure the accuracy of the standard concentration component oil sample. A high-concentration micro solenoid valve is installed at the bottom of the standard high-concentration characteristic gas component oil sample cylinder, a medium-concentration micro solenoid valve is installed at the bottom of the standard medium-concentration characteristic gas component oil sample cylinder, and a low-concentration micro solenoid valve is installed at the bottom of the standard low-concentration characteristic gas component oil sample cylinder. A high-concentration miniature solenoid valve is connected via a pipeline to the fourth channel of the multi-channel switching valve of the online dissolved gas monitoring device for the insulating oil under test; a medium-concentration miniature solenoid valve is connected via a pipeline to the fifth channel of the same device; and a low-concentration miniature solenoid valve is connected via a pipeline to the sixth channel. The oil sample cylinders containing the above standard high, medium, and low concentration characteristic gas components are pre-filled with standard high, medium, and low concentration characteristic gas component oil samples of known concentrations. The control module controls the online dissolved gas monitoring device in the insulating oil to detect these three oil samples with different known concentrations of characteristic gas components, in order to evaluate the accuracy, detection precision and linearity of the online dissolved gas monitoring device in the insulating oil, thereby inferring the degradation status of the online dissolved gas monitoring device in the insulating oil.

4. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 1, characterized in that: The multi-channel switching valve of the online monitoring device for dissolved gases in insulating oil to be detected is a six-way switching valve (9); the online monitoring device for dissolved gases in insulating oil is an online chromatographic monitoring device, a selective characteristic gas sensor detector, or an online spectral monitoring device; The second channel (15) of the six-way switching valve is connected to the second solenoid valve of the characteristic gas component saturated dissolution tank, and the first channel (14) of the six-way switching valve is connected to the external discharge port. A collection tank (8) is placed under the external discharge port. The collection tank is used to collect the discharged insulating oil for centralized treatment. The fourth channel (17) of the six-way switching valve is connected to the high-concentration micro solenoid valve, the fifth channel (18) of the six-way switching valve is connected to the medium-concentration micro solenoid valve, the sixth channel (19) of the six-way switching valve is connected to the low-concentration micro solenoid valve, and the third channel (16) of the six-way switching valve is used as a spare channel or a transfer channel. During accelerated degradation detection, the online monitoring device for dissolved gases in insulating oil detects the content of each component of the mixed characteristic gases contained in the insulating oil sample and transmits the detection data to the control module in real time.

5. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 1, characterized in that: The multi-channel switching valve of the online monitoring device for dissolved gases in the insulating oil to be detected is a six-way switching valve; the control module is also connected to the alarm, and the control module is pre-set with a control program for accelerating degradation detection, specifically including: A1. A program that controls the main transformer online equipment to automatically detect the concentration of characteristic gas components in the saturated dissolution tank every 60 minutes; A2. The program for automatically detecting standard high, medium and low known concentration characteristic gas components in oil samples of insulating oil by switching the online monitoring device for dissolved gas in the insulating oil at 240-hour intervals. When this program is executed, the automatic detection of the characteristic gas concentration of saturated components in the saturated dissolution tank of characteristic gas components is stopped. A3. Automatic alarm setting program for the online monitoring device for dissolved gases in insulating oil under test, detecting high, medium and low concentration characteristic gas components in oil samples, and setting the accuracy deviation range of the oil sample; A4. Automatic alarm setting program for the linear fit deviation range of oil sample in high, medium and low concentration characteristic gas components of the online monitoring device for dissolved gases in insulating oil; The input terminal of the control module is electrically connected to the data output terminal of the online dissolved gas monitoring device in the insulating oil to be tested and the output terminal of the external time relay, respectively. The output terminal of the control module is electrically connected to the six-way switching valve of the online dissolved gas monitoring device in the insulating oil to be tested, the first solenoid valve and the second solenoid valve of the characteristic gas component saturated dissolution tank, the magnetic stirrer of the characteristic gas component saturated dissolution tank, the high-concentration miniature solenoid valve of the standard high-concentration characteristic gas component oil sample cylinder, the medium-concentration miniature solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder, the low-concentration miniature solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder, and the input terminal of the alarm.

6. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 1, characterized in that: The accelerated degradation detection includes the following detection items; Project A involves using an online dissolved gas monitoring device to perform high-volume testing on saturated insulating oil containing characteristic gas components, in order to accelerate its aging process. Project B involves using an online monitoring device to control dissolved gases in accelerated aging insulating oil. This device compares and tests standard oil samples containing known concentrations of characteristic gases of high, medium, and low components within the oil sample cylinder to evaluate the device's performance after aging.

7. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 6, characterized in that: Project A includes the following steps; Step A1: Add the prepared characteristic gas component saturated solution insulating oil sample to the characteristic gas component saturated dissolution tank through the first solenoid valve, and close the first solenoid valve after filling. Step A2: The flexible corrugated expansion joint installed on the top of the characteristic gas component saturated dissolution tank is used to balance and compensate for the pressure change inside the saturated dissolution tank. When the pressure inside the dissolution tank increases, the corrugated expansion joint stretches and expands, and conversely, it contracts and descends. When the saturated concentration insulating oil sample inside the characteristic gas component saturated dissolution tank is consumed by the detection process, causing the flexible corrugated expansion joint to retract to the lowest position, the saturated concentration insulating oil sample is added to the tank. Step A3: Turn on the magnetic stirrer in the dissolving tank (4); Step A4: Open the second solenoid valve of the dissolving tank; Step A5: Turn on the online monitoring device for dissolved gas in the insulating oil to be tested; Step A6: After the online monitoring device for dissolved gas in the tested insulating oil is running stably, switch the operating condition of the six-way switching valve to the first channel of the six-way switching valve to connect to the second solenoid valve of the saturated dissolving tank, use a small amount of saturated solution insulating oil sample in the dissolving tank to flush the pipeline, and discharge the flushing oil into the collection tank (8) through the external discharge port of the first channel of the six-way valve. Step A7: After rinsing, switch the operating condition of the six-way switching valve to the second channel (15) of the six-way switching valve and connect it to the second solenoid valve of the saturated dissolving tank. After the saturated solution insulating oil sample in the dissolving tank is quantitatively extracted by the online monitoring device for dissolved gas in the insulating oil being tested, close the second solenoid valve and close the magnetic stirrer. Step A8: During the detection process, the gas or liquid sample released from the saturated solution insulating oil sample is detected by the adsorption column, detector or sensing unit of the online monitoring device for dissolved gases in the insulating oil being tested. Step A9: After the online monitoring device for dissolved gases in the tested insulating oil has completed its detection, it should be automatically shut down. Step A10: After the time since the last test reaches the set 60-minute interval, the same work of steps A4 to A9 will be automatically repeated until 240 hours, so as to accelerate the aging of the online monitoring device for dissolved gas in the tested insulating oil. Step A11: In the above steps, the online monitoring device for dissolved gases in the insulating oil being tested transmits the detection data to the control module in real time. When the deviation of the detection data exceeds the set value, the control module controls the alarm to sound.

8. The device for accelerated degradation detection in an online monitoring device for dissolved gases in insulating oil according to claim 7, characterized in that: Project B includes the following steps; Step B1: The online monitoring device for dissolved gases in the insulating oil under test performs accelerated aging treatment by testing the saturated solution insulating oil sample. After the aging treatment time reaches 240 hours, the online monitoring device for dissolved gases in the insulating oil under test is turned on, and the solenoid valve of the first channel (14) of the six-way switching valve is connected to the standard low concentration characteristic gas component oil sample cylinder (13). Step B2: Open the solenoid valve of the standard low concentration characteristic gas component oil sample cylinder, first use a small amount of low concentration standard mixed oil sample in the standard low concentration characteristic gas component oil sample cylinder to flush the pipeline, and discharge the flushing oil to the collection tank (8) through the external discharge port of the first channel (14) of the six-way switching valve. Step B3: Switch the sixth channel (19) of the six-way switching valve to be connected to the solenoid valve of the standard low-concentration characteristic gas component oil sample cylinder. After the online monitoring device for dissolved gas in the tested insulating oil quantitatively extracts the known standard low-concentration insulating oil in the standard low-concentration characteristic gas component oil sample cylinder, it closes the miniature solenoid valve of the oil sample cylinder. Step B4: At this point, the gas or liquid sample containing a known low concentration of dissolved gas from the insulating oil is quantitatively detected by the adsorption column, detector, or sensor of the online monitoring device for dissolved gases in the insulating oil being tested, and the detection data is transmitted to the control module in real time. Step B5: After the online monitoring device for dissolved gases in the insulating oil under test has completed the test on the insulating oil sample containing a known low concentration, the solenoid valve of the first channel (14) of the six-way switching valve is switched to connect with the solenoid valve of the standard medium concentration characteristic gas component oil sample cylinder (12). Step B6: Open the solenoid valve of the standard medium concentration characteristic gas component oil sample cylinder (12), first flush the pipeline with a small amount of known medium concentration standard mixed oil sample, and discharge the flushing oil to the collection tank through the external discharge port of the first channel of the six-way switching valve. Step B7: Switch the second channel (15) of the six-way switching valve to the solenoid valve of the standard medium-concentration characteristic gas component oil sample cylinder (12). After the online monitoring device for dissolved gas in insulating oil quantitatively extracts the known medium-concentration insulating oil in the standard medium-concentration characteristic gas component oil sample cylinder (12), close the miniature solenoid valve of the oil sample cylinder. Step B8: At this point, the gas or liquid sample containing a known medium concentration of dissolved gas from the insulating oil is quantitatively detected by the adsorption column, detector, or sensor of the online monitoring device for dissolved gases in the insulating oil being tested, and the detection data is transmitted to the control module in real time. Step B9: Similar to the above steps, the online monitoring device for dissolved gases in the insulating oil under test detects and transmits the detection data of the known high-concentration characteristic gas component oil sample in the standard high-concentration characteristic gas component oil sample cylinder (11). Step B10: If the accuracy, precision, and linearity of the detection data of the online monitoring device for dissolved gases in the insulating oil exceed the set range for the three different known concentrations of characteristic gas components in the oil sample, the alarm will sound, indicating to the staff that the online monitoring device for dissolved gases in the insulating oil can no longer meet the performance requirements after accelerated degradation treatment and is not suitable for practical use.

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