Gas calibration method and system for on-line monitoring device of dissolved gas in insulating oil

Abstract

The application discloses a kind of insulating oil dissolved gas on-line monitoring device's mark gas self-calibration method and system, comprising: under the condition of normal mark gas pressure, continuous mark gas calibration is carried out;Determine the relative standard deviation of gas component concentration or peak height / peak area under continuous mark gas calibration, if the relative standard deviation is not less than the set threshold, continue to carry out mark gas calibration until the relative standard deviation is less than the set threshold, and the number of continuous calibration does not exceed the maximum calibration number;If the maximum calibration number is reached, the relative standard deviation still does not meet the requirements, then trigger calibration abnormal alarm;When the relative standard deviation meets the requirements, the average concentration of gas components or the average value of peak height / peak area is obtained, which is compared with the last calibration data and the first calibration data, and the termination calibration process, correction mark gas coefficient or trigger calibration abnormal alarm operation is carried out according to the comparison result. Periodic mark gas calibration of monitoring devices with different detection principles is realized, and the operation and maintenance workload is reduced.

Description

Technical Field

[0001] This invention relates to the field of automated online monitoring technology for power equipment, and in particular to a self-calibration method and system for a calibration gas of an online monitoring device for dissolved gases in insulating oil. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Online monitoring devices for dissolved gases in insulating oil are widely used in substations, converter stations, power plants, and other locations because they can identify faults in oil-filled electrical equipment in real time and quickly, and issue alarms. During operation, these devices often experience increased measurement errors and reduced stability due to aging, malfunctions, or damage to components, as well as improper operation and maintenance, rendering them ineffective for online monitoring. Currently, reference oil samples are required for device testing. However, due to the large number of installed units in the field, testing is time-consuming and labor-intensive, and a testing cycle of 1-2 years is insufficient to complete the testing of all devices. Furthermore, the test results often show that about half of the devices do not meet the standard requirements. Therefore, relying solely on preparing reference oil samples for device testing is clearly insufficient; it is necessary to shorten the testing cycle and promptly identify the main problems in the devices.

[0004] Regardless of whether the detection principle is gas chromatography or photoacoustic spectroscopy, the core component of the device is the detection module, which is also the part most prone to aging or damage. Regular calibration with standard gases can promptly identify and quickly resolve problems. However, existing standard gas calibration technologies are difficult to integrate due to differences in components and systems from different manufacturers, and there is a lack of standardized operation and maintenance strategies, so they have not yet been implemented. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes a self-calibration method and system for online monitoring devices of dissolved gases in insulating oil. This system enables periodic automatic calibration of online monitoring devices for dissolved gases in insulating oil based on different detection principles, automatically detects problems such as abnormalities and aging of the device's detection module, and impure gas production by the carrier gas pump, effectively reducing the workload of operation and maintenance management.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a self-calibration method for a calibration gas of an online monitoring device for dissolved gases in insulating oil, comprising:

[0008] Perform continuous calibration with standard gas under normal standard gas pressure.

[0009] Determine the relative standard deviation of gas component concentration or peak height / peak area under continuous standard gas calibration. If the relative standard deviation is not less than the set threshold, continue the standard gas calibration until the relative standard deviation is less than the set threshold and the number of continuous calibrations does not exceed the maximum number of calibrations. If the relative standard deviation still does not meet the requirements when the maximum number of calibrations is reached, trigger a calibration anomaly alarm.

[0010] Obtain the average concentration of gas components or the average peak height / peak area when the relative standard deviation meets the requirements, and compare it with the previous calibration data and the first calibration data. Based on the comparison results, terminate the calibration process, correct the calibration gas coefficient, or trigger a calibration anomaly alarm.

[0011] As an alternative implementation, it is determined whether the calibration gas pressure is normal. If the calibration gas pressure is less than the first threshold and decreases by the second threshold compared to the previous calibration gas pressure, the calibration gas pressure is abnormal, an alarm is triggered, and the calibration process is terminated; otherwise, continuous calibration gas calibration is performed if the calibration gas pressure is normal.

[0012] As an alternative implementation method, a single standard gas process includes:

[0013] Based on the principle of gas chromatography detection, the following steps are performed in sequence: chromatographic preheating, baseline stabilization, standard gas purging, injection, chromatographic sampling, spectral analysis, and determination of the retention time of standard gas components.

[0014] If the deviation between the retention time of the standard gas component and the initial calibration exceeds the third threshold, the retention time is abnormal and an alarm is issued. At this time, the retention time of the standard gas component is modified to the retention time of the currently calibrated standard gas component; otherwise, the single standard gas calibration is terminated.

[0015] As an alternative implementation method, based on the principle of gas chromatography detection, chromatographic preheating is first performed, and then the baseline is determined to be stable. If the baseline is not stable and the preheating time has not been exceeded, chromatographic preheating is continued until the baseline is stable.

[0016] If the warm-up timeout occurs, regardless of whether the baseline is stable, the warm-up timeout will be triggered and an alarm will be issued, terminating the calibration process.

[0017] If the baseline is stable and the preheating time has not exceeded the limit, then perform standard gas purging, sample injection, chromatographic sampling, spectral analysis, and determination of the retention time of standard gas components.

[0018] As an alternative implementation, the process of comparing the data with the previous calibration data and the initial calibration data includes:

[0019] If the relative standard deviation from the previous calibration data is not greater than the fifth threshold, and the relative standard deviation from the first calibration data is not greater than the sixth threshold, the calibration coefficient will not be modified, and the calibration process will be terminated.

[0020] If the relative standard deviation from the previous calibration data is between the fifth and seventh thresholds, and the relative standard deviation from the first calibration data is between the sixth and eighth thresholds, the calibration coefficient is corrected.

[0021] If the relative standard deviation from the previous calibration data is not less than the seventh threshold, and the relative standard deviation from the first calibration data is not less than the eighth threshold, a calibration anomaly alarm is triggered, and the process is terminated.

[0022] As an alternative implementation method, the modified standard gas coefficient is the initial calibration concentration or peak height / peak area divided by the current calibration concentration or peak height / peak area.

[0023] In a second aspect, the present invention provides a calibration gas self-calibration system for an online monitoring device for dissolved gases in insulating oil, comprising: a gas source module, a gas path module, and a control module;

[0024] The gas source module includes a standard gas cylinder, a pressure sensor, and a gas pressure reducing valve. The standard gas cylinder is connected to the gas pressure reducing valve, and a pressure sensor is installed between the standard gas cylinder and the gas pressure reducing valve.

[0025] The gas circuit module includes a vent pipe and a calibration valve. The gas pressure reducing valve is connected to the detection module of the dissolved gas online monitoring device through the vent pipe, and a calibration valve is installed on the vent pipe.

[0026] The control module is used to control the conduction of the calibration gas valve so that the gas source module and the detection module are connected during calibration gas calibration, and the calibration gas self-calibration method according to any one of claims 1-6 is performed.

[0027] As an alternative implementation, the standard gas cylinder is filled with a standard mixed gas, which is based on nitrogen and mixed with methane, ethylene, ethane, acetylene, hydrogen, carbon monoxide and carbon dioxide.

[0028] As an optional implementation method, the concentration ranges of each gas include: methane 30 μL / L to 200 μL / L, ethylene 30 μL / L to 200 μL / L, ethane 30 μL / L to 200 μL / L, acetylene 10 μL / L to 100 μL / L, hydrogen 200 μL / L to 1000 μL / L, carbon monoxide 300 μL / L to 2500 μL / L, and carbon dioxide 1000 μL / L to 4000 μL / L.

[0029] As an alternative implementation, the detection module is also connected to the degassing module via a vent pipe. When oil sample testing is performed, the control module controls the standard gas valve to be in a state where the degassing module and the detection module are connected.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The self-calibration method and system for online monitoring of dissolved gases in insulating oil proposed in this invention can perform periodic automatic calibration of online monitoring devices for dissolved gases in insulating oil with different detection principles. It is applicable to any detection principle device, has a simple structure, is easy to modify, has complete protection facilities, saves time and effort, and has a high degree of automation. It can detect abnormalities or aging of the core components of the device in a timely manner, has an automatic calibration function, and effectively reduces the workload of operation and maintenance management.

[0032] The self-calibration method and system for the online monitoring device of dissolved gases in insulating oil proposed in this invention can automatically detect problems such as abnormality and aging of the device's detection module and impurity of the carrier gas pump in a short time without relying on long-term detection of the reference oil sample. At the same time, it provides protection through graded alarms. It does not require complex calculations of sensitivity, resolution, etc. It only requires simple adjustment of the retention time, standard gas detection concentration or peak height / peak area according to the setting deviation value judgment rules to modify the coefficients, thereby achieving the function of calibrating the detection module.

[0033] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0035] Figure 1 This is a flowchart of the self-calibration method for standard gas provided in Embodiment 1 of the present invention;

[0036] Figure 2 This is a flowchart of a single calibration gas test provided in Embodiment 1 of the present invention;

[0037] Figure 3 This is a schematic diagram of the self-calibration system for calibration gas provided in Embodiment 2 of the present invention;

[0038] Figure 4 This is a verification data diagram of the self-calibration method for standard gas provided in Embodiment 2 of the present invention;

[0039] The components include: 1. Standard gas cylinder; 2. Pressure sensor; 3. Gas pressure reducing valve; 4. Standard gas valve. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0044] Example 1

[0045] This embodiment provides a self-calibration method for a calibration gas of an online monitoring device for dissolved gases in insulating oil, mainly including parameter setting, calibration process, graded alarm, and data correction; such as Figure 1 As shown, it specifically includes:

[0046] (1) After the online monitoring device for dissolved gases in insulating oil has completed the oil sample testing and reached the parameter setting number of oil tests, the self-calibration program for standard gas is started.

[0047] First, it is necessary to determine whether the standard gas pressure is normal. If the standard gas pressure is less than the first threshold and decreases by the second threshold compared to the previous standard gas pressure, the standard gas pressure is abnormal, and an alarm is issued with a "strong" warning level, terminating the process. Otherwise, continuous standard gas calibration is performed if the standard gas pressure is normal.

[0048] As an alternative implementation, the first threshold value ranges from 0.1 MPa to 0.3 MPa, and the second threshold value ranges from 0.02 MPa to 0.1 MPa; in this embodiment, the first threshold is 0.1 MPa and the second threshold is 0.05 MPa.

[0049] like Figure 2 As shown, a single standard gas process includes:

[0050] (1-1) According to the gas chromatography detection principle device, first perform chromatographic preheating, then determine whether the baseline is stable. If the baseline is not stable and the preheating time has not exceeded, continue chromatographic preheating until the baseline is stable.

[0051] (1-2) If the preheating timeout occurs, regardless of whether the baseline is stable, an alarm message "preheating timeout" will be displayed with a "strong" warning level, and the process will be terminated.

[0052] (1-3) If the baseline is stable and the preheating time has not exceeded, then perform standard gas purging, injection, chromatographic sampling, spectral analysis, and determination of the retention time of standard gas components;

[0053] (1-4) If the deviation between the retention time of the standard gas component and the first calibration exceeds the third threshold, an alarm will be triggered indicating "abnormal retention time" with a "weak" level, and the retention time of the standard gas component will be automatically modified to the retention time of the currently calibrated standard gas component; otherwise, the single standard gas calibration will be terminated directly.

[0054] As an optional implementation, the value range of the third threshold is ±5% to ±15%, and in this embodiment, the third threshold is ±10%.

[0055] (2) Repeat the single standard gas calibration multiple times (in this embodiment, the standard gas calibration is performed three times in succession first), and calculate the relative standard deviation (RSD) of the gas component concentration or peak height / peak area under the continuous standard gas calibration.

[0056] (3) If the RSD is not less than the fourth threshold, add one calibration gas calibration and continue to calculate the RSD of the last three consecutive calibrations until the RSD is less than the fourth threshold and the number of consecutive calibrations does not exceed the maximum number of calibrations; if the RSD still does not meet the requirements when the maximum number of calibrations is reached, an alarm message "calibration gas repeatability abnormal" will be issued with a warning level of "weak" and the process will be terminated.

[0057] As an alternative implementation, the fourth threshold value ranges from ±1% to ±5%, and in this embodiment, the fourth threshold value is ±3%.

[0058] As an alternative implementation method, the maximum number of calibrations in this embodiment is 6.

[0059] (4) Obtain the average concentration of gas components or the average peak height / peak area when the RSD meets the requirements, and compare it with the previous calibration data and the initial calibration data; specifically:

[0060] (4-1) If the relative standard deviation from the previous calibration data is not greater than the fifth threshold and the relative standard deviation from the first calibration data is not greater than the sixth threshold, the calibration coefficient is not modified and the calibration process is terminated.

[0061] (4-2) If the relative standard deviation from the previous calibration data is between the fifth and seventh thresholds, and the relative standard deviation from the first calibration data is between the sixth and eighth thresholds, then the calibration coefficient is corrected.

[0062] (4-3) If the relative standard deviation from the previous calibration data is not less than the seventh threshold and the relative standard deviation from the first calibration data is not less than the eighth threshold, a calibration anomaly alarm is triggered with a "strong" prompt level, and the process is terminated.

[0063] As an optional implementation, the value range of the fifth threshold is ±1% to ±5%, and in this embodiment, the fifth threshold is ±3%.

[0064] The value range of the sixth threshold is ±3% to ±10%, and in this embodiment, the sixth threshold is ±5%.

[0065] The value range of the seventh threshold is ±5% to ±10%, and in this embodiment, the seventh threshold is ±10%.

[0066] The value range of the eighth threshold is ±20% to ±40%, and in this embodiment, the eighth threshold is ±30%.

[0067] In this embodiment, the modified standard gas coefficient is: ki' = initial calibration concentration or peak height / peak area ÷ current calibration concentration or peak height / peak area.

[0068] In this embodiment, the above-mentioned standard gas self-calibration process is designed with a hierarchical alarm mode, with a total of 5 alarm situations:

[0069] First, when the standard gas pressure is less than the first threshold and decreases by the second threshold compared to the previous standard gas pressure, an alarm will be triggered indicating "abnormal standard gas pressure" with a "strong" alert level.

[0070] Second, when the preheating stability timeout is exceeded, an alarm message "preheating timeout" will be displayed, with the warning level being "strong".

[0071] Third, when the maximum number of calibrations is reached, if the relative standard deviation still does not meet the parameter tuning requirements, an alarm will be triggered indicating "abnormal repeatability of calibration gas", with the warning level being "weak".

[0072] Fourth, when the deviation between the standard gas detection retention time and the initial calibration does not meet the parameter tuning requirements, an alarm will be triggered indicating "abnormal retention time" with a "weak" warning level.

[0073] Fifth, when the concentration of standard gas components or peak height / peak area exceeds the parameter tuning requirements, an alarm will be triggered indicating "abnormal standard gas concentration" with a "strong" warning level.

[0074] In this embodiment, the above-mentioned standard gas self-calibration process is designed with a data correction mode, specifically including:

[0075] When the deviation between the retention time of the calibrated gas component and the initial calibration exceeds the parameter tuning requirements, the system automatically modifies the retention time to match the most recent retention time.

[0076] When the relative standard deviation of a calibration component concentration or peak height / peak area from the previous calibration data is between the fifth and seventh thresholds, and the relative standard deviation from the first calibration data is between the sixth and eighth thresholds, the standard curve coefficients are automatically modified.

[0077] Example 2

[0078] like Figure 3 As shown, this embodiment provides a calibration gas self-calibration system for an online monitoring device for dissolved gases in insulating oil, which implements the calibration gas self-calibration method described in Embodiment 1, and includes a gas source module, a gas path module, and a control module.

[0079] In this embodiment, the gas source module includes a standard gas cylinder 1, a pressure sensor 2, and a gas pressure reducing valve 3; the gas outlet of the standard gas cylinder 1 is connected to the gas pressure reducing valve 3, and the pressure sensor 2 is installed between the standard gas cylinder 1 and the gas pressure reducing valve 3.

[0080] The standard gas cylinder 1 is filled with a standard mixed gas, which is based on nitrogen and mixed with methane, ethylene, ethane, acetylene, hydrogen, carbon monoxide and carbon dioxide gases of known concentrations.

[0081] As an alternative implementation method, the concentration ranges of other gases are: methane 30 μL / L to 200 μL / L, ethylene 30 μL / L to 200 μL / L, ethane 30 μL / L to 200 μL / L, acetylene 10 μL / L to 100 μL / L, hydrogen 200 μL / L to 1000 μL / L, carbon monoxide 300 μL / L to 2500 μL / L, and carbon dioxide 1000 μL / L to 4000 μL / L.

[0082] As an alternative implementation, the standard gas cylinder 1 has a volume of 2L to 8L and a standard gas filling pressure of 10.5Mpa.

[0083] In this embodiment, the gas path module includes a vent pipe and a standard gas valve 4. The vent pipe is connected to a gas pressure reducing valve 3, a carrier gas module, a degassing module, and a detection module of an online dissolved gas monitoring device.

[0084] A standard gas valve 4 is installed between the gas pressure reducing valve 3, the carrier gas module, the detection module and the degassing module. The standard gas valve 4 is connected to the gas pressure reducing valve 3, the carrier gas module, the detection module and the degassing module respectively. The control module controls the opening of the standard gas valve 4 so that the standard gas from the gas source module or the sample gas from the degassing module can enter the detection module.

[0085] Specifically, when oil sample testing is required, the calibration gas valve is in a state where the degassing module and the testing module are connected; when calibration gas calibration is required, the calibration gas valve is in a state where the gas source module and the testing module are connected.

[0086] In this embodiment, the control module automatically controls all electrical components through a lower-level computer program, including functions such as calibration gas self-calibration process, calibration gas monitoring, alarm function, and parameter modification.

[0087] In this embodiment, the self-calibration system and method for standard gas are validated. A self-calibration system for standard gas is installed on the online monitoring device for dissolved gases in insulating oil. A 30L reference oil sample, prepared and stably stored for more than 7 days, is used. Offline chromatographic analysis is performed daily to ensure that the oil sample concentration remains essentially constant. The oil sample concentration and standard gas concentration are shown in Table 1.

[0088] Table 1 Concentration of oil sample and standard gas

[0089]

[0090]

[0091] The unit's oil sample monitoring cycle was set to 4 hours, and the standard gas cycle was set to calibrate after 6 oil measurements. It operated continuously for 5 days, performing a total of 5 standard gas self-calibrations. The operating data is as follows: Figure 4 As shown, the results indicate that the system and process are operating normally, the oil sample monitoring and standard gas calibration data are stable, and there is no cross-interference between the oil sample and the standard gas.

[0092] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A self-calibration method for calibration gas of an online monitoring device for dissolved gases in insulating oil, characterized in that, include: Perform continuous calibration with standard gas under normal standard gas pressure. A single standard gas process includes: Based on the principle of gas chromatography detection, the following steps are performed in sequence: chromatographic preheating, baseline stabilization, standard gas purging, injection, chromatographic sampling, spectral analysis, and determination of the retention time of standard gas components. If the deviation between the retention time of the standard gas component and the initial calibration exceeds the third threshold, the retention time is abnormal and an alarm is triggered. At this time, the retention time of the standard gas component is modified to the current calibrated retention time of the standard gas component; otherwise, the single standard gas calibration is terminated. Determine the relative standard deviation of gas component concentration or peak height / peak area under continuous standard gas calibration. If the relative standard deviation is not less than the set threshold, continue the standard gas calibration until the relative standard deviation is less than the set threshold and the number of continuous calibrations does not exceed the maximum number of calibrations. If the relative standard deviation still does not meet the requirements when the maximum number of calibrations is reached, trigger a calibration anomaly alarm. Obtain the average concentration of gas components or the average peak height / peak area when the relative standard deviation meets the requirements, and compare it with the previous calibration data and the first calibration data. Based on the comparison results, perform operations such as terminating the calibration process, correcting the standard gas coefficient, or triggering a calibration anomaly alarm. The process of comparing the data with the previous calibration data and the initial calibration data includes: If the relative standard deviation from the previous calibration data is not greater than the fifth threshold, and the relative standard deviation from the first calibration data is not greater than the sixth threshold, the calibration coefficient will not be modified, and the calibration process will be terminated. If the relative standard deviation from the previous calibration data is between the fifth and seventh thresholds, and the relative standard deviation from the first calibration data is between the sixth and eighth thresholds, the calibration coefficient is corrected. If the relative standard deviation from the previous calibration data is not less than the seventh threshold, and the relative standard deviation from the first calibration data is not less than the eighth threshold, a calibration anomaly alarm is triggered, and the process is terminated.

2. The self-calibration method for the online monitoring device of dissolved gases in insulating oil as described in claim 1, characterized in that, Determine if the calibration gas pressure is normal. If the calibration gas pressure is less than the first threshold and decreases by the second threshold compared to the previous calibration gas pressure, the calibration gas pressure is abnormal, an alarm is triggered, and the calibration process is terminated. Otherwise, perform continuous calibration with standard gas under normal standard gas pressure.

3. The self-calibration method for the online monitoring device of dissolved gases in insulating oil as described in claim 1, characterized in that, According to the principle of gas chromatography detection, chromatographic preheating is performed first, and then the baseline is determined to be stable. If the baseline is not stable and the preheating time has not been exceeded, chromatographic preheating is continued until the baseline is stable. If the warm-up timeout occurs, regardless of whether the baseline is stable, the warm-up timeout will be triggered and an alarm will be issued, terminating the calibration process. If the baseline is stable and the preheating time has not exceeded the limit, then perform standard gas purging, sample injection, chromatographic sampling, spectral analysis, and determination of the retention time of standard gas components.

4. The self-calibration method for the online monitoring device of dissolved gases in insulating oil as described in claim 1, characterized in that, The revised standard gas coefficient is the initial calibration concentration or peak height / peak area divided by the current calibration concentration or peak height / peak area.

5. A calibration system for an online monitoring device for dissolved gases in insulating oil, employing the calibration method for an online monitoring device for dissolved gases in insulating oil as described in any one of claims 1-4, characterized in that, include: Gas source module, gas path module, and control module; The gas source module includes a standard gas cylinder, a pressure sensor, and a gas pressure reducing valve. The standard gas cylinder is connected to the gas pressure reducing valve, and a pressure sensor is installed between the standard gas cylinder and the gas pressure reducing valve. The gas circuit module includes a vent pipe and a calibration valve. The gas pressure reducing valve is connected to the detection module of the dissolved gas online monitoring device through the vent pipe, and a calibration valve is installed on the vent pipe. The control module is used to control the opening of the calibration gas valve so that the gas source module and the detection module are connected during calibration gas calibration.

6. The calibration gas self-calibration system of the online monitoring device for dissolved gases in insulating oil as described in claim 5, characterized in that, The standard gas cylinder is filled with a standard mixed gas, which is based on nitrogen and mixed with methane, ethylene, ethane, acetylene, hydrogen, carbon monoxide and carbon dioxide.

7. The calibration gas self-calibration system of the online monitoring device for dissolved gases in insulating oil as described in claim 6, characterized in that, The concentration ranges for each gas are as follows: methane 30 μL / L~200 μL / L, ethylene 30 μL / L~200 μL / L, ethane 30 μL / L~200 μL / L, acetylene 10 μL / L~100 μL / L, hydrogen 200 μL / L~1000 μL / L, carbon monoxide 300 μL / L~2500 μL / L, and carbon dioxide 1000 μL / L~4000 μL / L.

8. The calibration gas self-calibration system of the online monitoring device for dissolved gases in insulating oil as described in claim 5, characterized in that, The detection module is also connected to the degassing module via a vent pipe. When oil sample testing is performed, the control module controls the standard gas valve to be in a state where the degassing module and the detection module are connected.

Images