Main transformer oil chromatography online monitoring method and device

Abstract

The invention discloses a main transformer oil chromatography on-line monitoring method and device. The method comprises the following steps: sampling from a transformer and carrying out preliminary separation; after the separated gas is mixed with constant-flow carrier gas generated by a carrier gas generator, sample gas uniformly flows out; qualitative and quantitative analysis of the gas is realized; and displaying in the forms of a Dawei triangle state, a gas content data histogram state and a main gas three-ratio state. The combination of gravity and centrifugal separation and the application of an ultrasonic technology ensure that an oil sample extracted from the transformer can be subjected to accurate and deep separation treatment; the carrier gas with constant flow is mixed with the separated gas, so that the uniformity and consistency of the sample gas flowing into the gas chromatograph are ensured, analysis results are summarized and reported in three visual and easy-to-understand forms, the accuracy and efficiency of fault detection are improved, and the detection efficiency is improved. Powerful technical support is provided for preventive maintenance and fault early warning of the transformer, and safe and stable operation of a power system is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of transformer online monitoring, and in particular to a main transformer oil chromatogram online monitoring method and device. Background Art

[0002] With the rapid development of power systems, transformers, as core equipment for power transmission and distribution, have a direct impact on the safety and reliability of the power grid due to their operational stability. However, during long-term operation, transformers will produce various dissolved gases due to factors such as aging, overheating, and discharge of insulating materials. The types and content of these gases can reflect the health of the transformer. Therefore, online monitoring of dissolved gases in transformer oil is of great significance for preventing transformer failures.

[0003] The existing transformer oil chromatography online monitoring method mainly relies on regular offline sampling and analysis, which is not only time-consuming and labor-intensive, but also unable to reflect the gas changes inside the transformer in real time, and has a certain lag. In addition, although the traditional gas chromatography analysis method can realize the qualitative and quantitative analysis of gas, it is complicated to operate, has high requirements on environmental conditions, and is difficult to realize automation and intelligence. It can be seen that the existing technology still needs to be improved and enhanced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a main transformer oil chromatogram online monitoring method and device, which is used to solve the problem in the prior art that transformer oil chromatogram monitoring results have obvious lag and are difficult to automate.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a main transformer oil chromatographic online monitoring method, comprising the following steps: S1. A certain amount of transformer oil is regularly and accurately extracted from the transformer through a sampling valve, and the oil and gas are preliminarily separated by a method combining gravity separation and centrifugal separation; S2. A temperature and humidity sensor and an electronic control system are used to monitor and adjust the temperature and humidity in the monitoring room in real time to keep the temperature in the monitoring room constant; S3. The ultrasonic frequency is adjusted according to the characteristics of the oil sample and the separation requirements, and ultrasonic technology is used to further accelerate the release of dissolved gas in the oil; S4. The separated gas is mixed with a constant flow carrier gas generated by a carrier gas generator, and the sample gas flows out evenly after maintaining a constant pressure; S5. The sample gas enters the gas chromatograph, and through the separation effect of the chromatographic column, the qualitative and quantitative analysis of the gas is achieved according to the different distribution coefficients of each component between the stationary phase and the mobile phase; S6. The analysis results are automatically processed by software to generate a detection report containing gas component concentrations and change trend information, and are displayed in the form of David triangle status, gas content data histogram status and main gas three ratio status.

[0006] In one embodiment of the present invention, step S1 includes that the sample oil first enters a pretreatment unit, and the pretreatment unit uses a filter to remove impurities and particles in the oil.

[0007] The beneficial effects of the above embodiments are that the filter removes impurities and particulate matter in the oil, improves the efficiency and accuracy of oil-gas separation, and reduces interference in subsequent analysis.

[0008] In one embodiment of the present invention, step S2 includes installing a temperature and humidity sensor, a vibration sensor, and an electromagnetic interference sensor to measure the environmental parameters in the monitoring room in real time and record the data; when the monitored environmental parameters exceed the alarm threshold, the alarm system is triggered.

[0009] The beneficial effects of the above embodiments are: real-time monitoring and adjustment of the temperature and humidity in the monitoring room to ensure the stability of the analysis environment; at the same time, by installing a variety of sensors, an alarm is triggered when environmental parameters are abnormal, thereby ensuring the safety and reliability of the analysis process.

[0010] In one embodiment of the present invention, step S4 includes: the separated gas sample is connected to the injection valve and the gas sample is introduced; the carrier gas generator generates a constant flow of carrier gas and introduces it through the channel of the injection valve; the gas sample and the carrier gas are mixed in the mixing chamber of the injection valve; the internal pressure of the mixing chamber is adjusted according to the flow generated by the carrier gas generator to evenly flow out the mixed sample gas.

[0011] The beneficial effects of the above embodiment are: the separated gas sample is mixed with a carrier gas of a constant flow rate, and by adjusting the internal pressure of the mixing chamber, a uniform outflow of the sample gas is achieved, providing a stable gas source for subsequent chromatographic analysis and maintaining the stability of continuous monitoring.

[0012] In one embodiment of the present invention, in step S5, the chromatograph is equipped with a hydrogen flame ionization detector FID or a mass spectrometer detector MSD to improve the detection limit and resolution, record the chromatogram in real time, and automatically calculate the concentration of each component through a built-in algorithm.

[0013] In order to achieve the above-mentioned purpose, the present invention also adopts the following technical scheme: a main transformer oil chromatographic online monitoring device, comprising: a sampling valve, fixed to the oil output port at the bottom of the transformer, used to extract the transformer oil in the transformer; a degassing module, connected to the transformer through the sampling valve, and using a combination of gravity separation and centrifugal separation to perform preliminary separation of oil and gas; a carrier gas generator, generating a stable and constant flow carrier gas for mixing with the gas after oil and gas separation; an injection valve, the injection port of which is respectively connected to the degassing module and the carrier gas generator, and the carrier gas and the sample gas are mixed in the built-in mixing chamber; a chromatographic column, connected to the sample outlet port of the injection valve, separating and detecting the mixed gas to be detected, and determining the components and content of the gas to be detected; a data processing module, collecting the gas data to be detected obtained by quantitative analysis of the chromatographic column, and forming David's triangle state, gas content data histogram state and main gas three ratio state respectively and displaying them interactively.

[0014] In one embodiment of the present invention, the degassing module includes an ultrasonic unit, and an ultrasonic transducer in the ultrasonic unit converts an electrical signal generated by an ultrasonic generator into mechanical vibration, and transmits the mechanical vibration to the transformer oil for oil-gas separation.

[0015] In one embodiment of the present invention, the data processing module includes a David's Triangle status unit to display the relative contents of hydrogen, alkane and acetylene gases and identify the aging or fault type of the transformer oil.

[0016] The beneficial effect of the above embodiment is that by displaying the relative contents of hydrogen, alkane and acetylene gases, the aging or fault type of transformer oil can be intuitively identified, providing an important basis for the maintenance and management of the transformer.

[0017] In one embodiment of the present invention, an oil return valve is further included. The oil return valve is fixed to the oil input port at the bottom of the transformer. The degassing module re-inputs the separated transformer oil into the transformer through the oil return valve.

[0018] In one embodiment of the present invention, a solenoid valve control module unit is also included, which is respectively connected to the sampling valve, the oil return valve and the injection valve signal to control the opening and closing degree of the valve body.

[0019] In one embodiment of the present invention, the data processing module includes a David's triangle state unit, which displays the relative content of hydrogen, alkane and acetylene gases to identify the aging or fault type of transformer oil; a gas content data histogram unit, which clearly presents the specific concentration value of each gas component to facilitate quantitative analysis; and a gas three-ratio state unit, which calculates and displays the three ratios of C2H2 / C2H4, CH4 / H2, and C2H6 / C2H4 in the reference standard.

[0020] The beneficial effects of the above embodiment are: clearly presenting the specific concentration value of each gas component, facilitating quantitative analysis, and providing detailed data support for transformer fault diagnosis. In addition, by calculating and displaying the three ratios of C2H2 / C2H4, CH4 / H2, and C2H6 / C2H4 in the reference standard, the fault type and severity of the transformer can be more accurately judged, providing a scientific basis for the maintenance and replacement of the transformer.

[0021] As described above, the main transformer oil chromatography online monitoring method and device of the present invention have the following beneficial effects: the combination of gravity and centrifugal separation and the use of ultrasonic technology ensure that the oil sample extracted from the transformer can be accurately and deeply separated and processed, effectively improving the extraction accuracy of the gas components; on this basis, through the precise regulation of the temperature and humidity sensor and the electronic control system, the constant temperature and pressure state of the monitoring room environment is maintained, providing stable and reliable conditions for subsequent chromatographic analysis, and the constant flow of carrier gas is mixed with the separated gas to ensure the uniformity and consistency of the sample gas when it flows into the gas chromatograph, and realize the precise qualitative and quantitative analysis of the gas components, which not only reveals the specific composition of the dissolved gas in the transformer oil, but also reflects the internal state and potential problems of the transformer through the concentration change trend; the analysis results are summarized and reported in three intuitive and easy-to-understand forms: David triangle state, gas content data histogram state, and main gas three ratio state. Through multi-dimensional data display, the operating state of the transformer can be fully and real-time reflected; not only the accuracy and efficiency of fault detection are improved, but also strong technical support is provided for preventive maintenance and fault warning of transformers, ensuring the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A flow chart of the main transformer oil chromatogram online monitoring method provided by the present invention; Figure 2 This is a schematic diagram of the main transformer oil chromatography online monitoring device provided by the present invention.

[0024] Component number description 1 transformer, 2 sampling valve, 3 degassing module, 4 carrier gas generator, 5 injection valve, 6 chromatographic column, 7 data processing module, 8 oil return valve, 9 data diagnosis unit, 10 early warning unit. DETAILED DESCRIPTION

[0025] The present invention provides a main transformer oil chromatogram online monitoring method and device. In order to make the purpose, technical scheme and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples.

[0026] In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "up, down, left, right, etc." are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and should not be understood as limitations on the present invention; in addition, the terms "installation" and "connection" should be understood in a broad sense, and ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0027] Embodiment 1 See also Figure 1 The present invention provides a main transformer oil chromatographic online monitoring method, comprising the following steps: S1. extracting a certain amount of transformer oil from the transformer regularly and accurately through a sampling valve, and performing preliminary separation of oil and gas through a method combining gravity separation and centrifugal separation; the sample oil first enters a pretreatment unit, and the pretreatment unit uses a filter to remove impurities and particulate matter in the oil. The filter removes impurities and particulate matter in the oil, thereby improving the efficiency and accuracy of oil and gas separation and reducing interference in subsequent analysis.

[0028] S2. Use temperature and humidity sensors and electronic control systems to monitor and adjust the temperature and humidity in the monitoring room in real time to keep the temperature in the monitoring room constant; install temperature and humidity sensors, vibration sensors and electromagnetic interference sensors to measure the environmental parameters in the monitoring room in real time and record the data; when the monitored environmental parameters exceed the alarm threshold, trigger the alarm system, monitor and adjust the temperature and humidity in the monitoring room in real time, and ensure the stability of the analysis environment; at the same time, by installing multiple sensors, trigger the alarm when the environmental parameters are abnormal, ensuring the safety and reliability of the analysis process.

[0029] S3. Adjust the ultrasonic frequency according to the characteristics of the oil sample and the separation requirements, and use ultrasonic technology to further accelerate the release of dissolved gas in the oil; specifically, for oil samples with higher viscosity, a lower ultrasonic frequency may be required to generate a stronger impact force to help gas molecules escape from the oil; and for oil samples with more dissolved gas types or higher concentrations, it may be necessary to increase the ultrasonic frequency to accelerate the release rate of different types of gas and improve the separation efficiency. In addition, the use of ultrasonic technology needs to be combined with other separation methods such as gravity separation and centrifugal separation to form a complete oil and gas separation system. In this system, ultrasonic technology plays a key acceleration role, making the entire separation process more efficient and accurate.

[0030] S4. The separated gas is mixed with the constant flow carrier gas generated by the carrier gas generator, and the sample gas flows out evenly after maintaining a constant pressure; specifically, the separated gas sample is connected to the injection valve and the gas sample is introduced; the carrier gas generator generates a constant flow carrier gas which is introduced through the channel of the injection valve; the gas sample and the carrier gas complete gas mixing in the mixing chamber of the injection valve; the internal pressure of the mixing chamber is adjusted according to the flow generated by the carrier gas generator to evenly flow out the mixed sample gas, the separated gas sample is mixed with the constant flow carrier gas, and the internal pressure of the mixing chamber is adjusted to achieve even outflow of the sample gas, thereby providing a stable gas source for subsequent chromatographic analysis and maintaining the stability of continuous monitoring.

[0031] S5. The sample gas enters the gas chromatograph, and through the separation effect of the chromatographic column, the qualitative and quantitative analysis of the gas is achieved according to the different distribution coefficients of each component between the stationary phase and the mobile phase; wherein the chromatograph is equipped with a hydrogen flame ionization detector FID or a mass spectrometer detector MSD to improve the detection limit and resolution, record the chromatogram in real time, and automatically calculate the concentration of each component through a built-in algorithm.

[0032] S6. The analysis results are automatically processed by the software to generate a test report containing gas component concentration and change trend information, and are displayed in the form of David triangle status, gas content data histogram status, and main gas three ratio status. That is, after the analysis results are automatically processed by a highly intelligent software system, a detailed and comprehensive test report can be quickly generated. This report not only contains the precise concentration data of various gas components in the transformer oil, but also deeply analyzes the change trend of these gas components over time, providing technicians with important reference information on the operating status of the transformer. More detailed, the report adopts a variety of intuitive and easy-to-understand display forms. Among them, the David triangle state diagram displays the relative content of hydrogen, alkane and acetylene gases, allowing technicians to quickly identify the degree of aging of the transformer oil and possible fault types. The graphical expression method not only improves the efficiency of data analysis, but also lowers the threshold for technicians' professional knowledge. In addition, the gas content data histogram status clearly presents the specific concentration values ​​of each gas component in the form of a bar chart, allowing technicians to intuitively see the distribution of each gas component in the transformer oil, which helps technicians to conduct more precise quantitative analysis and thus more accurately judge the operating status of the transformer. At the same time, the report also shows the three ratios of the main gases, namely the ratios of C2H2 / C2H4, CH4 / H2, and C2H6 / C2H4 in the reference standard. These ratios are an important basis for transformer fault diagnosis, which can help technicians understand the chemical changes inside the transformer more deeply, so as to more accurately determine the type and severity of the fault.

[0033] Embodiment 2 See also Figure 2 The present invention provides a main transformer oil chromatographic online monitoring device, including: a sampling valve 2, fixed to the oil output port at the bottom of the transformer 1, used to extract the transformer oil in the transformer 1; a degassing module 3, connected to the transformer 1 through the sampling valve 2, and using a method combining gravity separation and centrifugal separation to perform preliminary separation of oil and gas; a carrier gas generator 4, generating a stable and constant flow carrier gas for mixing with the gas after oil and gas separation; an injection valve 5, the injection port is respectively connected to the degassing module 3 and the carrier gas generator 4, and the carrier gas and the sample gas are mixed in the built-in mixing chamber; a chromatographic column 6, connected to the sample outlet port of the injection valve 5, separates and detects the mixed gas to be detected, and determines the components and content of the gas to be detected; a data processing module 7, collects the gas data to be detected obtained by quantitative analysis of the chromatographic column 6, and respectively forms David triangle state, gas content data histogram state and main gas three ratio state and displays interactively. The device is closely connected to the oil output port at the bottom of the transformer 1 through the sampling valve 2, and can regularly and accurately extract the transformer oil inside the transformer 1 as an analysis sample.

[0034] In the oil-gas separation stage, the device adopts an efficient method combining gravity separation and centrifugal separation to ensure the initial separation effect of oil and gas. Furthermore, in order to accelerate the release of gas molecules dissolved in the oil, an ultrasonic unit is specially added to the degassing module 3. The ultrasonic unit efficiently converts the electrical signal generated by the ultrasonic generator into mechanical vibration through its internal ultrasonic transducer, which directly acts on the transformer oil, thereby achieving further optimization of oil-gas separation.

[0035] The sample gas after preliminary separation is then fully mixed with the stable and constant flow carrier gas generated by the carrier gas generator 4 in the gas mixing chamber of the injection valve 5. This step ensures the uniformity and stability of the sample gas and provides a reliable gas source for subsequent chromatographic analysis. In this embodiment, the carrier gas generator 4 is an integrated generator of high-purity hydrogen and zero-grade air carrier gas, which can stably produce zero-grade air carrier gas with a total hydrocarbon content of less than 50ppb, a flow rate of more than 1L / min, and a pressure stability of better than 1%. It can replace the traditional bottled high-pressure carrier gas and avoid the cross-field operation occupation requirements of the maintenance personnel to operate the gas cylinder.

[0036] The chromatographic column 6 is filled with an efficient separation medium, which can accurately and quickly separate and detect the mixed gas to be detected. By measuring parameters such as the retention time and peak area of ​​each gas component, the chromatographic column 6 can accurately determine the component and content of the gas to be detected.

[0037] It also includes an oil return valve 8, which is fixed to the oil input port at the bottom of the transformer 1. The degassing module 3 re-inputs the separated transformer oil into the transformer 1 through the oil return valve 8. It also includes an electromagnetic valve control module unit, which is respectively connected to the sampling valve 2, the oil return valve 8 and the injection valve 5 by signal to control the opening and closing degree of the valve body.

[0038] The data processing module 7 is responsible for collecting the quantitative analysis data output by the chromatographic column 6 and performing in-depth processing through advanced algorithms and models. This module can not only generate a detailed detection report containing information such as gas component concentration and change trend, but also clearly present the analysis results in a variety of intuitive and easy-to-understand display forms such as David's triangle state, gas content data histogram, and main gas three ratio states.

[0039] The David Triangle state unit provides technicians with an important basis for intuitively judging transformer oil aging or fault types by displaying the relative contents of hydrogen, alkanes and alkynes. The gas content data histogram unit clearly and accurately presents the specific concentration values ​​of each gas component, making it easier for technicians to conduct in-depth quantitative analysis and fault diagnosis.

[0040] In addition, as an important part of the data processing module 7, the gas three ratio state unit provides technicians with a more accurate and scientific basis for judging the fault type and severity of the transformer 1 by calculating and displaying the ratios of C2H2 / C2H4, CH4 / H2, and C2H6 / C2H4 in the reference standard. The realization of this function not only improves the accuracy and reliability of transformer 1 fault diagnosis, but also provides a strong scientific basis for the maintenance and replacement of the transformer 1.

[0041] In this embodiment, the data processing module 7 includes a data diagnosis unit 9 and an early warning unit 10. The data diagnosis unit 9 performs analysis and diagnosis based on the quantitative analysis data output by the chromatographic column 6, and warns the operator or the system through the early warning unit 10 when the normal operating state is exceeded.

[0042] In summary, the main transformer oil chromatography online monitoring method and device of the present invention, the combination of gravity and centrifugal separation and the application of ultrasonic technology ensure that the oil sample extracted from the transformer can be accurately and deeply separated and processed, and the extraction accuracy of the gas components is effectively improved; on this basis, through the precise regulation of the temperature and humidity sensor and the electronic control system, the constant temperature and pressure state of the monitoring room environment is maintained, which provides stable and reliable conditions for subsequent chromatographic analysis, and the constant flow of carrier gas is mixed with the separated gas to ensure the uniformity and consistency of the sample gas when it flows into the gas chromatograph, and realizes the accurate qualitative and quantitative analysis of the gas components, which not only reveals the specific composition of the dissolved gas in the transformer oil, but also reflects the internal state and potential problems of the transformer through the concentration change trend; the analysis results are summarized and reported in three intuitive and easy-to-understand forms: David triangle state, gas content data histogram state and main gas three ratio state, and the operating state of the transformer is comprehensively and real-timely reflected through multi-dimensional data display; not only the accuracy and efficiency of fault detection are improved, but also strong technical support is provided for the preventive maintenance and fault warning of the transformer, ensuring the safe and stable operation of the power system. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0043] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A main transformer oil chromatogram online monitoring method, characterized in that: The steps include: S1. Regularly and accurately extract a certain amount of transformer oil from the transformer through a sampling valve, and perform preliminary separation of oil and gas by combining gravity separation with centrifugal separation; S2. Use temperature and humidity sensors and electronic control systems to monitor and adjust the temperature and humidity in the monitoring room in real time to keep the temperature in the monitoring room constant; S3. Adjust the ultrasonic frequency according to the oil sample characteristics and separation requirements, and use ultrasonic technology to further accelerate the release of dissolved gas in the oil; S4. The separated gas is mixed with a constant flow carrier gas generated by a carrier gas generator, and the sample gas flows out uniformly after maintaining a constant pressure; S5. The sample gas enters the gas chromatograph and is separated by the chromatographic column to achieve qualitative and quantitative analysis of the gas according to the different distribution coefficients of each component between the stationary phase and the mobile phase; S6. The analysis results are automatically processed by the software to generate a test report containing gas component concentrations and change trend information, and are displayed in the form of David triangle status, gas content data histogram status and main gas three ratio status.

2. The main transformer oil chromatogram online monitoring method according to claim 1 is characterized in that: Step S1 includes that the sample oil first enters a pretreatment unit, and the pretreatment unit uses a filter to remove impurities and particulate matter in the oil.

3. The main transformer oil chromatogram online monitoring method according to claim 1 is characterized in that: Step S2 includes installing temperature and humidity sensors, vibration sensors and electromagnetic interference sensors to measure the environmental parameters in the monitoring room in real time and record the data; when the monitored environmental parameters exceed the alarm threshold, the alarm system is triggered.

4. The main transformer oil chromatogram online monitoring method according to claim 1 is characterized in that: Step S4 includes: The separated gas sample is connected to the injection valve and the gas sample is introduced; the carrier gas generator generates a constant flow of carrier gas which is introduced through the channel of the injection valve; The gas sample and the carrier gas are mixed in the mixing chamber of the injection valve; the internal pressure of the mixing chamber is adjusted according to the flow rate generated by the carrier gas generator to evenly flow out the mixed sample gas.

5. The main transformer oil chromatogram online monitoring method according to claim 1 is characterized in that: In step S5, the chromatograph is equipped with a hydrogen flame ionization detector FID or a mass spectrometer detector MSD to improve the detection limit and resolution, record the chromatogram in real time, and automatically calculate the concentration of each component through a built-in algorithm.

6. A main transformer oil chromatography online monitoring device, characterized in that: include: The sampling valve is fixed to the oil output port at the bottom of the transformer and is used to extract the transformer oil in the transformer; The degassing module is connected to the transformer through a sampling valve and uses a combination of gravity separation and centrifugal separation to perform preliminary separation of oil and gas; A carrier gas generator generates a stable and constant flow of carrier gas for mixing with the gas after oil and gas separation; Injection valve, the injection port is connected to the degassing module and the carrier gas generator respectively, and the carrier gas and the sample gas are mixed in the built-in gas mixing chamber; The chromatographic column is connected to the sample outlet port of the injection valve to separate and detect the mixed gas to be detected, and to determine the components and content of the gas to be detected; The data processing module collects the gas data to be detected obtained by quantitative analysis of the chromatographic column, forms David triangle state, gas content data histogram state and main gas three ratio state respectively and displays them interactively.

7. The main transformer oil chromatogram online monitoring device according to claim 6 is characterized in that: The degassing module comprises an ultrasonic unit, in which an ultrasonic transducer converts an electrical signal generated by an ultrasonic generator into mechanical vibration and transmits the mechanical vibration to the transformer oil for oil-gas separation.

8. The main transformer oil chromatogram online monitoring device according to claim 6 is characterized in that: It also includes an oil return valve, which is fixed to the oil input port at the bottom of the transformer. The degassing module re-inputs the separated transformer oil into the transformer through the oil return valve.

9. The main transformer oil chromatogram online monitoring device according to claim 8, characterized in that: It also includes an electromagnetic valve control module unit, which is respectively connected to the sampling valve, the oil return valve and the injection valve signal to control the opening and closing degree of the valve body.

10. The main transformer oil chromatogram online monitoring device according to claim 6, characterized in that: The data processing module includes a David's Triangle status unit, which displays the relative contents of hydrogen, alkane and acetylene gases and identifies the aging or fault type of transformer oil; a gas content data histogram unit, which clearly presents the specific concentration value of each gas component for quantitative analysis; and a gas three-ratio status unit, which calculates and displays the three ratios of C2H2 / C2H4, CH4 / H2 and C2H6 / C2H4 in the reference standard.

Images