Transformer oil chromatography high-precision online monitoring device

Abstract

The present invention discloses a high-precision online monitoring device for transformer oil chromatography, which belongs to the technical field of transformer monitoring. The device comprises: a transformer oil cylinder, an oil pump, an oil-gas separation module, a gas collection module, a gas chromatography identification module, a buffer oil return module, a first valve, a second valve, a third valve, a fourth valve, a communication module and a controller; the gas chromatography identification module comprises a chromatographic column and a thermal conductivity detector, and a mixed gas is separated by the chromatographic column. The gas outlet of the chromatographic column is connected to the thermal conductivity detector, and the components and concentration of the gas flowing out of the chromatographic column are converted into an electrical signal that can be collected by the thermal conductivity detector, and the collected chromatographic signal is sent to a server through the communication module. The server performs remote data analysis to detect the components and concentration of the mixed gas to monitor the status of the transformer.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer monitoring, and in particular relates to a high-precision online monitoring device for transformer oil chromatography. Background Art

[0002] Transformers are an important link in the power grid system. Once a fault occurs, it may cause major accidents and disasters in the entire power system. In the daily operation of the transformer, its operating status must be detected to provide early warning of transformer faults and timely detect potential transformer faults. This is crucial for the safe and reliable operation of the entire power system, reducing fault repair time and reducing economic losses.

[0003] Most high-voltage transformers, both domestically and internationally, use oil-immersed transformers. Transformer oil is a mixture of long-chain or cyclic hydrocarbon chains extracted from petroleum. When a transformer experiences certain faults, characteristic gases are generated within the oil. For example, electrical and thermal faults produce gases like hydrogen, ethylene, and acetylene. Transformer oil oxidation can also lead to the accumulation of carbon monoxide and carbon dioxide. Therefore, analyzing the composition and concentration of gases in transformer oil is one of the key criteria for diagnosing transformer faults. The concentrations of hydrogen, methane, ethane, ethylene, and acetylene are crucial indicators for determining internal faults in power transformers.

[0004] Traditional transformer monitoring methods often require operation and maintenance personnel to regularly visit each transformer one by one to conduct on-site inspection and maintenance of the transformer's operating status. Not only is the labor cost high, but human factors often lead to errors in the inspection results, making it difficult to accurately detect transformer faults. Summary of the Invention

[0005] To address the technical problem that traditional transformer monitoring methods often require operation and maintenance personnel to regularly visit each transformer to conduct on-site inspections and maintenance of the transformer's operating status, which not only has high labor costs but also often leads to errors in the inspection results due to human factors, making it difficult to accurately detect transformer faults, the present invention provides a high-precision online transformer oil chromatography monitoring device.

[0006] The present invention provides a transformer oil chromatogram high-precision online monitoring device, comprising: a transformer oil cylinder, an oil pump, an oil-gas separation module, a gas collection module, a gas chromatogram identification module, a buffer oil return module, a first valve, a second valve, a third valve, a fourth valve, a communication module and a controller;

[0007] The oil outlet of the transformer oil cylinder is connected to the oil inlet of the oil pump, the oil outlet of the oil pump is connected to the oil inlet of the oil-gas separation module through a first valve, the oil outlet of the oil-gas separation module is connected to the oil inlet of the buffer oil return module, and the oil outlet of the buffer oil return module is connected to the oil inlet of the oil cylinder; the gas outlet of the oil-gas separation module is connected to the gas inlet of the gas collection module through a second valve, the gas outlet of the gas collection module is connected to the gas inlet of the gas chromatogram identification module through a third valve, and the gas outlet of the gas chromatogram identification module is connected to the outside world through a fourth valve;

[0008] The gas chromatography identification module includes a chromatographic column and a thermal conductivity detector. The gas outlet of the gas collection module is connected to the gas inlet of the chromatographic column through the third valve. When the first valve, the second valve, the third valve and the fourth valve are opened under the control of the controller, the mixed gas is separated by the chromatographic column. The gas outlet of the chromatographic column is connected to the thermal conductivity detector. The thermal conductivity detector converts the components and concentration of the gas flowing out of the chromatographic column into an electrical signal that can be collected, and the collected chromatographic signal is sent to the server through the communication module. The server performs remote data analysis to detect the components and concentration of the mixed gas to monitor the status of the transformer.

[0009] Compared with the prior art, the present invention has at least the following beneficial effects:

[0010] In this invention, a gas mixture is separated using a chromatographic column. The column's outlet is connected to a thermal conductivity detector, which converts the composition and concentration of the gas flowing out of the column into a collectible electrical signal. This signal is then transmitted to a server via a communication module. The server performs remote data analysis, detecting the composition and concentration of the gas mixture for online monitoring of the transformer's status. This eliminates the need for regular visits to individual transformer sites, reducing labor costs while automating and mechanizing the gas mixture testing. This effectively eliminates human interference and enables high-precision testing of transformer oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The preferred embodiments will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0012] Figure 1 This is a structural schematic diagram of a transformer oil chromatogram high-precision online monitoring device provided by the present invention;

[0013] Figure 2 This is a structural schematic diagram of a magnetic stirrer provided by the present invention;

[0014] Figure 3 This is a structural diagram of a buffer net provided by the present invention;

[0015] Figure 4 It is a structural schematic diagram of a gas chromatography identification module provided by the present invention. DETAILED DESCRIPTION

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without inventive work.

[0017] To simplify the drawings, only portions relevant to the invention are schematically depicted in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one component with the same structure or function is schematically depicted or labeled. In this document, "one" not only means "only one" but also "more than one."

[0018] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0019] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0020] In addition, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0021] In one embodiment, the reference Figure 1 , a structural schematic diagram of a transformer oil chromatography high-precision online monitoring device provided by the present invention.

[0022] The present invention provides a high-precision online monitoring device for transformer oil chromatography, comprising: a transformer oil cylinder 1, an oil pump 2, an oil-gas separation module 3, a gas collection module 4, a gas chromatography identification module 5, a buffer oil return module 6, a first valve 7, a second valve 8, a third valve 9, a fourth valve 10, a communication module and a controller.

[0023] It should be noted that the oil-gas separation module 3 is used to separate the oil and gas in the oil sample to be tested. The gas collection module 4 is used to collect the separated gas. The gas chromatogram identification module 5 is used to identify the composition and concentration of the gas to be tested. The buffer oil return module 6 is used to return the separated oil to the transformer oil cylinder 1.

[0024] Specifically, the oil outlet of the transformer oil cylinder 1 is connected to the oil inlet of the oil pump 2, which is connected to the oil inlet of the oil-gas separation module 3 via a first valve 7. The oil outlet of the oil-gas separation module 3 is connected to the oil inlet of the buffer oil return module 6, which in turn is connected to the oil inlet of the oil cylinder. The gas outlet of the oil-gas separation module 3 is connected to the gas inlet of the gas collection module 4 via a second valve 8. The gas outlet of the gas collection module 4 is connected to the gas inlet of the gas chromatogram identification module 5 via a third valve 9. The gas outlet of the gas chromatogram identification module 5 is connected to the outside world via a fourth valve 10.

[0025] The gas chromatography identification module 5 includes a chromatographic column 51 and a thermal conductivity detector 52. The gas outlet of the gas collection module 4 is connected to the gas inlet of the chromatographic column 51 through the third valve 9. When the first valve 7, the second valve 8, the third valve 9 and the fourth valve 10 are opened at the same time under the control of the controller, the mixed gas is separated by the chromatographic column 51. The gas outlet of the chromatographic column 51 is connected to the thermal conductivity detector 52. The thermal conductivity detector 52 converts the components and concentration of the gas flowing out of the chromatographic column 51 into an electrical signal that can be collected, and the collected chromatographic signal is sent to the server through the communication module. The server performs remote data analysis to detect the components and concentration of the mixed gas to monitor the status of the transformer.

[0026] It should be noted that the gas chromatography identification module 5 can detect the gas composition and concentration in the gas to be tested. The concentration of gases such as CH4, C2H6, C2H4, C2H2, CO, CO2, and H2 contained in transformer oil is an important basis for judging internal faults of power transformers.

[0027] Common transformer failure types include overheating, partial discharge, spark discharge, and arc discharge. Different types of faults often produce different gases. Therefore, online server analysis of the composition and concentration of dissolved gases in transformer oil can determine whether a transformer fault has occurred and what type of fault it is. The server can then dispatch maintenance personnel to the transformer for verification and maintenance as needed, eliminating the need for regular visits to each transformer. This reduces labor costs and significantly reduces transformer failure rates.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] In the present invention, a chromatographic column 51 separates the mixed gas. The outlet of the chromatographic column 51 is connected to a thermal conductivity detector 52. The thermal conductivity detector 52 converts the composition and concentration of the gas flowing out of the chromatographic column 51 into a collectible electrical signal. The collected chromatographic signal is then transmitted to a server via a communication module. The server performs remote data analysis to detect the composition and concentration of the mixed gas, enabling online monitoring of the transformer's status. This eliminates the need for regular visits to each transformer, reducing labor costs while automating and mechanizing the testing of the mixed gas. This effectively eliminates human interference and achieves high-precision testing of transformer oil.

[0030] In a possible implementation, the transformer oil chromatogram high-precision online monitoring device further includes: a first vacuum pump 11 and a fifth valve 12 .

[0031] The first vacuum pump 11 is connected to the gas inlet of the gas collection module 4 through the fifth valve 12 .

[0032] The transformer oil cylinder 1, oil pump 2, first valve 7, oil-gas separation module 3, and buffer oil return module 6 form the oil circuit. The gas collection module 4, third valve 12, and gas chromatogram identification module 5 form the gas circuit. Second valve 8 isolates the oil circuit from the gas circuit.

[0033] Among them, under the control of the controller, when the first valve 7 is opened, the second valve 8 is closed, the third valve 9 is opened, the fourth valve 10 is opened, and the fifth valve 12 is opened, the oil pump 2 is turned on to clean the oil circuit, and the first vacuum pump 11 is turned on to clean the gas circuit.

[0034] Before the formal test begins, the oil pump 2 can be used to clean the oil circuit to avoid residual transformer oil from the previous test in the oil circuit, and the first vacuum pump 11 can be used to clean the gas circuit to avoid residual gas from the previous test in the gas chamber, thereby improving the accuracy of dissolved gas detection.

[0035] In a possible implementation, the oil-gas separation module 3 includes a degassing tank 31 , a first magnetic stirrer 32 , and a liquid level sensor 33 .

[0036] The oil outlet of the oil pump 2 is connected to the oil inlet of the degassing tank 31 through the first valve 7, the oil outlet of the degassing tank 31 is connected to the oil inlet of the buffer oil return module 6, and the air outlet of the degassing tank 31 is connected to the air inlet of the gas collection module 4 through the second valve 8.

[0037] The liquid level sensor 33 is disposed in the degassing tank 31 . When the liquid level sensor 33 detects that the liquid level in the degassing tank 31 has reached a preset liquid level, the first valve 7 is closed.

[0038] The liquid level sensor 33 and the first valve 7 cooperate to achieve accurate rated amount extraction of transformer oil during each test.

[0039] The first magnetic stirrer 32 is disposed at the bottom of the degassing tank 31 and is used to stir the transformer oil in the degassing tank 31 .

[0040] Reference Manual Figure 2 , a structural schematic diagram of a magnetic stirrer provided by the present invention.

[0041] The first magnetic stirrer 32 includes a stator 321 and a stirrer 322. The stator 321 includes a base 3211 and four electromagnetic assemblies 3212. The four electromagnetic assemblies 3212 are arranged in a 2×2 manner on the base 3211. The electromagnetic assembly 3212 includes a coil 32121, an iron core 32122 and a magnetic pole 32123. The coil 32121, the iron core 32122 and the magnetic pole 32123 constitute a magnetic circuit. The stirrer 322 is arranged on the four magnetic poles 32123. The stirrer 322 is a permanent magnet.

[0042] By changing the magnetic force generated by the four electromagnetic components 3212 and controlling the stirrer 322 to rotate smoothly, the transformer oil in the degassing tank 31 is stirred, so that the gas dissolved in the transformer oil is released as much as possible, thereby improving the accuracy of gas detection.

[0043] It should be noted that the magnetic stirrer does not need to come into contact with the transformer oil when stirring the transformer oil, which can avoid contamination of the transformer oil during the stirring process and avoid distortion of the test results.

[0044] In one possible embodiment, the transformer oil chromatogram high-precision online monitoring device further includes a sixth valve 13, and the gas collection module 4 includes a gas collecting tank 41 and a variable-diameter piston 42. A variable-diameter piston 42 is provided in the gas collecting tank 41. The variable-diameter piston 42 forms a gas collecting chamber at the top of the gas collecting tank 41, and the gas collecting chamber is provided with an air inlet and an air outlet. The air outlet of the oil-gas separation module 3 is connected to the air inlet of the gas collecting tank 41 through the second valve 8, and the air outlet of the gas collecting tank 41 is connected to the air inlet of the gas chromatogram identification module 5 through the third valve 9. The variable-diameter piston 42 forms a vacuum chamber at the bottom of the gas collecting tank 41, and the first vacuum pump 11 is connected to the vacuum chamber through the sixth valve 13.

[0045] To collect gas from the oil-gas separation module 3, the sixth valve 13 is opened, and the first vacuum pump 11 is activated to evacuate the vacuum chamber. The sixth valve 13 is then closed, and the second valve 8 is opened. The variable piston 42 then moves to its bottom, drawing gas from the oil-gas separation module 3 into the gas collection chamber. To transfer gas from the gas collection tank 41 to the gas chromatogram identification module 5, the second valve 8 is closed, and the third valve 9 is opened. The variable piston 42 then moves to its top, transferring gas from the gas collection tank 41 to the gas chromatogram identification module 5.

[0046] It should be noted that collecting gas by drawing vacuum from the gas collecting tank 41 through the first vacuum pump 11 can, on the one hand, avoid the mixing of other gases during the collection process that may cause distortion of the detection results, and on the other hand, ensure that the gas in the oil-gas separation module 3 is completely collected in the gas collecting tank 41.

[0047] In the present invention, the first vacuum pump 11 is used to clean the gas path on the one hand, and to evacuate the vacuum chamber of the gas collecting tank 41 on the other hand, so as to extract the gas separated in the oil-gas separation module 3 into the gas collecting chamber of the gas collecting tank 41 .

[0048] In one possible embodiment, the buffer oil return module 6 includes a buffer oil return tank 61, a second vacuum pump 62, a second magnetic stirrer 63, a funnel 64, a buffer screen 65, and a seventh valve 66. A degassing chamber 67 and an oil return chamber 68 are provided within the buffer oil return tank 61. The degassing chamber 67 is connected to the oil return chamber 68 via the seventh valve 66.

[0049] The second vacuum pump 62 is connected to the degassing chamber 67, and the second magnetic stirrer 63 is arranged at the bottom of the degassing chamber 67. The second vacuum pump 62 is used to further degas the transformer oil in the degassing chamber 67 to discharge the gas in the transformer oil as much as possible.

[0050] The funnel 64 is arranged in the oil return chamber 68 , the oil inlet of the oil return chamber 68 is opposite to the inclined wall of the funnel 64 , the buffer net 65 is arranged at the oil outlet of the funnel 64 , and a plurality of oil return holes 651 are provided on the buffer net 65 .

[0051] Reference Manual Figure 3 , a schematic structural diagram of a buffer net 65 provided by the present invention.

[0052] It should be noted that the transformer oil first flows down along the inclined wall of the funnel 64 to perform the first pressure relief buffering, and then the transformer oil passes through the buffer net 65 for the second pressure relief buffering, which can prevent the transformer oil pressure from being too high and causing damage to the transformer oil cylinder 1 when it is returned.

[0053] In one possible embodiment, the gas chromatogram identification module 5 further includes a constant-temperature chamber 53, a nitrogen cylinder 54, and a signal recorder 55. A chromatographic column 51 and a thermal conductivity detector 52 are located within the constant-temperature chamber 53. The outlet of the nitrogen cylinder 54 is connected to the gas inlet of the chromatographic column 51, providing carrier gas for the mixed gas. The signal recorder 55 is connected to the thermal conductivity detector 52 and is configured to convert the composition and concentration of the gas flowing out of the chromatographic column 51 into a collectible electrical signal. The collected chromatographic signal is then transmitted to a server via a communication module. The server performs remote data analysis to detect the composition and concentration of the mixed gas and monitor the transformer's status.

[0054] Reference Manual Figure 4 , a schematic structural diagram of a gas chromatographic identification module 5 provided by the present invention.

[0055] In a possible implementation, the controller is configured to perform the following steps S101 to S104:

[0056] S101: Processing the chromatographic signal by using a fuzzy clustering algorithm to detect the composition and concentration of the mixed gas.

[0057] S102: When the concentration of the target gas contained in the gas to be measured is greater than an alarm threshold, it is determined that the transformer is in a dangerous state.

[0058] The concentrations of hydrogen, methane, ethane, ethylene, and acetylene are important indicators for determining internal faults in power transformers. The target gas can be any one or more of hydrogen, methane, ethane, ethylene, and acetylene.

[0059] It should be noted that different types of gases with excessive concentrations will result in different causes of internal transformer failures. Therefore, the composition of the gas being tested is also an important measurement that can help diagnose the type of transformer failure.

[0060] S103: The server notifies the maintenance personnel to go to the destination to confirm and maintain the status of the transformer.

[0061] S104: Compare the actual result of the transformer status confirmed by the maintenance personnel after arriving at the destination with the detection result of the gas detection model, and modify the alarm threshold.

[0062] In this invention, a fuzzy clustering algorithm is used to process chromatographic signals to detect the composition and concentration of the mixed gas. If the concentration of the target gas in the measured gas exceeds the alarm threshold, the transformer is determined to be in a dangerous state. The server then notifies maintenance personnel to travel to the designated location to verify and maintain the transformer's condition. This eliminates the need for regular visits to each transformer, reducing labor costs and significantly reducing transformer failure rates.

[0063] In one possible implementation, in order to determine whether the gas to be tested contains corresponding gas components, the controller is specifically configured to:

[0064] Construct m cluster centers, including hydrogen cluster center, methane cluster center, ethane cluster center, ethylene cluster center and acetylene cluster center.

[0065] Calculate the cluster center y of the tested sample i j The similarity p ij :

[0066]

[0067] d ij =||x i -y j ||

[0068] Among them, p ij Represents the sample to be tested x i and cluster center y j The similarity between ij Represents the sample to be tested x i and cluster center y j The Euclidean distance between .

[0069] Calculate the sample x to be tested i For cluster center y j The membership degree u ij :

[0070]

[0071] Among them, the membership degree u ij is the sample to be tested x i and cluster center y j The ratio of the similarity of the cluster to the sum of the similarities of all cluster centers.

[0072] Construct the objective function J(U,Y):

[0073]

[0074] Among them, the objective function is the weighted sum of squares of errors within the class, U is the fuzzy partition matrix, Y is the cluster center vector, α is the weighting index, α∈[1,+∞), and n is the number of samples to be tested.

[0075] The Lagrange multiplier method is used to solve the problem so that J(U,Y) takes the minimum value, and the fuzzy clustering iteration formula is obtained as follows:

[0076]

[0077] Use the fuzzy clustering iterative formula to iterate until convergence to determine the sample x to be tested i specific ingredients.

[0078] In one possible implementation, in order to determine the gas concentration in the gas to be measured, the controller is specifically configured to:

[0079] It is determined that the mixed gas includes the first gas and the second gas.

[0080] The chromatographic signal is divided into a signal duration of the first gas and a signal duration of the second gas.

[0081] The respective ratios and concentrations of the first gas and the second gas in the gas mixture are determined by the signal duration of the first gas and the signal duration of the second gas.

[0082] It should be noted that the mixed gas may contain other gases besides the first gas and the second gas, and the proportion and concentration of other gases in the mixed gas can be determined by using the duration of the gas signal.

[0083] In a possible implementation, in order to modify the alarm threshold, the controller is specifically configured to:

[0084] Compare the test results with the actual results and evaluate the test results, wherein the evaluation results include: changing the safety detection to a dangerous result, changing the dangerous detection to a safe result, changing the safety detection to a safe result, and changing the dangerous detection to a dangerous result.

[0085] Let the number of times the safe class result is predicted as safe be TX, the number of times the safe class result is predicted as dangerous be FY, the number of times the dangerous class result is predicted as dangerous be TY, and the number of times the dangerous class result is predicted as safe be FX, then the proportion of safe samples that are predicted incorrectly is FY rate and the proportion of dangerous samples that are predicted correctly FX rate for:

[0086]

[0087]

[0088] Let the cost of predicting a safe result as dangerous be p, and the cost of predicting a dangerous result as safe be q, and modify the alarm threshold so that:

[0089]

[0090] The cost of predicting a safety outcome as a dangerous outcome is p, which can be quantified by the labor cost of the operation and maintenance personnel to confirm the outcome. The cost of predicting a dangerous outcome as a safe outcome is q, which can be quantified by the economic losses caused by the damage to the transformer and the suspension of production and business due to the power outage.

[0091] Balancing the cost of predicting a safe situation as a dangerous situation (p) with the cost of predicting a dangerous situation as a safe situation (q) can keep the alarm threshold at an appropriate value, avoiding both excessive and false warnings.

[0092] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A high-precision online monitoring device for transformer oil chromatography, characterized in that: include: Transformer oil cylinder, oil pump, oil-gas separation module, gas collection module, gas chromatography identification module, buffer oil return module, first valve, second valve, third valve, fourth valve, communication module and controller; The oil outlet of the transformer oil cylinder is connected to the oil inlet of the oil pump, the oil outlet of the oil pump is connected to the oil inlet of the oil-gas separation module through the first valve, the oil outlet of the oil-gas separation module is connected to the oil inlet of the buffer oil return module, and the oil outlet of the buffer oil return module is connected to the oil inlet of the oil cylinder; the gas outlet of the oil-gas separation module is connected to the gas inlet of the gas collection module through the second valve, the gas outlet of the gas collection module is connected to the gas inlet of the gas chromatogram identification module through the third valve, and the gas outlet of the gas chromatogram identification module is connected to the outside world through the fourth valve; The gas chromatographic identification module includes a chromatographic column and a thermal conductivity detector. The gas outlet of the gas collection module is connected to the gas inlet of the chromatographic column through the third valve. When the first valve, the second valve, the third valve, and the fourth valve are opened simultaneously under the control of the controller, the mixed gas is separated by the chromatographic column. The gas outlet of the chromatographic column is connected to the thermal conductivity detector. The thermal conductivity detector converts the components and concentration of the gas flowing out of the chromatographic column into an electrical signal that can be collected. The collected chromatographic signal is sent to the server through the communication module. The server performs remote data analysis to detect the components and concentration of the mixed gas to monitor the status of the transformer. Wherein, the transformer oil chromatogram high-precision online monitoring device further comprises: a first vacuum pump and a fifth valve; The first vacuum pump is connected to the gas inlet of the gas collection module through the fifth valve; The transformer oil cylinder, the oil pump, the first valve, the oil-gas separation module, and the buffer oil return module constitute an oil circuit; the gas collection module, the third valve, and the gas chromatography identification module constitute a gas circuit; Wherein, under the control of the controller, when the first valve is opened, the second valve is closed, the third valve is opened, the fourth valve is opened, and the fifth valve is opened, the oil pump is turned on to clean the oil circuit, and the first vacuum pump is turned on to clean the gas circuit; Wherein, the transformer oil chromatogram high-precision online monitoring device further comprises: a sixth valve, the gas collection module comprises a gas collecting tank and a variable-diameter piston; The gas collecting tank is provided with a variable diameter piston; The variable-diameter piston forms a gas collecting chamber at the top of the gas collecting tank, and the gas collecting chamber is provided with an air inlet and an air outlet. The air outlet of the oil-gas separation module is connected to the air inlet of the gas collecting tank through the second valve, and the air outlet of the gas collecting tank is connected to the air inlet of the gas chromatogram identification module through the third valve. The variable-diameter piston forms a vacuum chamber at the bottom of the gas collecting tank, and the first vacuum pump is connected to the vacuum chamber through the sixth valve; Among them, the sixth valve is opened, and the first vacuum pump is started to evacuate the vacuum chamber; the fifth valve is closed, and the second valve is opened, and the variable piston moves to the bottom to extract the gas in the oil-gas separation module into the gas collecting chamber; the second valve is closed, and the third valve is opened, and the variable piston moves to the top to send the gas in the gas collecting tank into the gas chromatography identification module.

2. The transformer oil chromatogram high-precision online monitoring device according to claim 1 is characterized in that: The oil-gas separation module includes a degassing tank, a first magnetic stirrer and a liquid level sensor; The oil outlet of the oil pump is connected to the oil inlet of the degassing tank through the first valve, the oil outlet of the degassing tank is connected to the oil inlet of the buffer oil return module, and the gas outlet of the degassing tank is connected to the gas inlet of the gas collection module through the second valve; The liquid level sensor is provided in the degassing tank, and closes the first valve when the liquid level sensor detects that the liquid level in the degassing tank reaches a preset liquid level; The first magnetic stirrer is arranged at the bottom of the degassing tank, and is used to stir the transformer oil in the degassing tank; The first magnetic stirrer includes a stator and a stirrer. The stator includes a base and four electromagnetic components. The four electromagnetic components are arranged in a 2×2 manner on the base. The electromagnetic components include a coil, an iron core and a magnetic pole. The coil, the iron core and the magnetic pole constitute a magnetic circuit. The stirrer is arranged on the four magnetic poles. The stirrer is a permanent magnet. The stirrer is controlled to rotate smoothly by the four electromagnetic components.

3. The transformer oil chromatogram high-precision online monitoring device according to claim 1 is characterized in that: The buffer oil return module includes: a buffer oil return tank, a second vacuum pump, a second magnetic stirrer, a funnel, a buffer net and a seventh valve; The buffer oil return tank is provided with a degassing chamber and an oil return chamber inside, and the degassing chamber is connected to the oil return chamber through the seventh valve; The second vacuum pump is connected to the degassing chamber, and the second magnetic stirrer is arranged at the bottom of the degassing chamber; The funnel is arranged in the oil return chamber, the oil inlet of the oil return chamber is opposite to the inclined wall of the funnel, the buffer net is arranged at the oil outlet of the funnel, and the buffer net is provided with a plurality of oil return holes.

4. The transformer oil chromatogram high-precision online monitoring device according to claim 1, characterized in that: The gas chromatogram identification module also includes: a constant temperature chamber, a nitrogen bottle and a signal recorder; The chromatographic column and the thermal conductivity detector are arranged in the constant temperature chamber; The outlet of the nitrogen bottle is connected to the gas inlet of the chromatographic column to provide carrier gas for the mixed gas; The signal recorder is connected to the thermal conductivity detector, and is used to convert the components and concentration of the gas flowing out of the chromatographic column into an electrical signal that can be collected, and send the collected chromatographic signal to the server through the communication module.

5. The transformer oil chromatogram high-precision online monitoring device according to claim 4 is characterized in that: The controller is used to: Processing the chromatographic signal by a fuzzy clustering algorithm to detect the composition and concentration of the mixed gas; When the concentration of the target gas contained in the gas to be tested is greater than the alarm threshold, determining that the transformer is in a dangerous state and reporting the detection result to the server; The server notifies the maintenance personnel to go to the destination to confirm and maintain the status of the transformer; The actual result of the maintenance personnel confirming the status of the transformer after arriving at the destination is compared with the detection result of the gas detection model, and the alarm threshold is corrected.

6. The transformer oil chromatogram high-precision online monitoring device according to claim 5, characterized in that: The controller is specifically used for: Build m Cluster centers, including hydrogen cluster center, methane cluster center, ethane cluster center, ethylene cluster center and acetylene cluster center; Calculate the sample to be tested x i The cluster center y j Similarity p ij : in, p ij Indicates the sample to be tested x i and cluster centers y j The similarities between d ij Indicates the sample to be tested x i and cluster centers y j The Euclidean distance between Calculate the sample to be tested x i The cluster center y j Membership u ij : Among them, the membership u ij For the sample to be tested x i and cluster centers y j The ratio of the similarity of to the sum of similarities of all cluster centers; Constructing the objective function J ( U , Y ): The objective function is the weighted sum of square errors within the class, U is the fuzzy partitioning matrix, Y is the cluster center vector, α is the weighted index, , n is the number of samples to be tested; The Lagrange multiplier method is used to solve J ( U , Y ) takes the minimum value, and the fuzzy clustering iteration formula is obtained as follows: The fuzzy clustering iterative formula is used to iterate until convergence to determine the sample to be tested. x i specific ingredients.

7. The transformer oil chromatogram high-precision online monitoring device according to claim 6, characterized in that: The controller is specifically used for: determining that the mixed gas includes a first gas and a second gas; dividing the chromatographic signal into a signal duration of the first gas and a signal duration of the second gas; The respective ratios and concentrations of the first gas and the second gas in the mixed gas are determined by the signal duration of the first gas and the signal duration of the second gas.

8. The transformer oil chromatogram high-precision online monitoring device according to claim 5, characterized in that: The controller is specifically used for: Comparing the detection result with the actual result, and evaluating the detection result, wherein the evaluation result includes: changing the safety detection to a dangerous result, changing the dangerous detection to a safe result, changing the safety detection to a safe result, and changing the dangerous detection to a dangerous result; Let the number of times the safety prediction is a safety result be TX , the number of times the safety prediction is changed to the dangerous result is FY , the number of times the danger is predicted as a dangerous result is TY , the number of times the danger is predicted to be a safe result is FX , then the proportion of safety samples that are predicted incorrectly is FY rate and the proportion of dangerous samples predicted correctly FX rate for: Let the cost of predicting safety as dangerous be p , the cost of predicting danger as a safe outcome is q , the alarm threshold is modified so that: 。

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