Comparison and calibration device and method for online monitoring device of dissolved gas in main transformer oil

Abstract

The present invention relates to a comparison and calibration device and method for an online monitoring device for dissolved gas in oil of a main transformer. The device comprises a main transformer body, an online monitoring device for dissolved gas in oil, a four-way switching valve, a dynamic preparation characteristic gas component standard oil sample device and a control module. The online monitoring device for dissolved gas in oil is installed beside the main transformer body, and its oil sampling tube extends into the main transformer body. A four-way switching valve is installed on the oil sampling tube. The first channel of the four-way switching valve is connected to the online monitoring device for dissolved gas in oil, the second channel is connected to the dynamic preparation characteristic gas component standard oil sample device, the third channel is connected to the main transformer body, and the fourth channel is connected to an external discharge barrel; the control module is electrically connected to the online monitoring device for dissolved gas in oil, the four-way switching valve, and the dynamic preparation characteristic gas component standard oil sample device, respectively, to control the coordinated work of each part. The device and method are conducive to quickly and accurately performing online comparison and calibration on the online monitoring device for dissolved gas in oil of the main transformer.

Description

Technical Field

[0001] The invention belongs to the field of power transformers, and in particular relates to a comparison and calibration device and method for an online monitoring device for dissolved gas in main transformer oil. Background Art

[0002] In order to timely detect overheating and discharge faults in the main transformer, most large main transformers in the power system are now equipped with online monitoring devices for dissolved gases in oil. When overheating or discharge faults occur inside the main transformer, high temperature or high-energy discharge will occur at the fault point, causing the transformer oil around the fault point to crack and produce: hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide and other gases, collectively referred to as main transformer fault characteristic gases. These fault characteristic gases will be partially dissolved in the transformer oil. Through the online monitoring device for dissolved gases in oil, the component content and proportion of the characteristic gases in the transformer oil inside the main transformer can be analyzed online, so as to timely detect overheating or discharge faults inside the main transformer and judge the fault type and development trend. However, due to technical and equipment reasons, many online monitoring devices for dissolved gas in oil of main transformers have deviated after being used for a period of time, which affects the accuracy of the test and causes lags, misjudgments and overreactions in the detection of main transformer faults. The current approach is to manually take samples of main transformer oil and bring them back to the central laboratory every once in a while, and use offline chromatographic instruments for comparison tests. If the error is found to exceed the allowable range, the online monitoring device for dissolved gas in oil is calibrated and compared at the main transformer site of the substation through a fixed standard concentration characteristic gas. These have seriously affected the reliable use of the online monitoring device for dissolved gas in oil of the main transformer, and also affected the safe operation of the main transformer. Therefore, it is of great significance to develop a device that can accurately compare and calibrate the online monitoring device for dissolved gas in oil of the main transformer in a timely manner. Summary of the invention

[0003] The object of the present invention is to provide a comparison and calibration device and method for an online monitoring device for dissolved gas in main transformer oil, which is conducive to quickly and accurately performing online comparison and calibration on the online monitoring device for dissolved gas in main transformer oil.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a comparison and calibration device for an online monitoring device of dissolved gas in oil of a main transformer, comprising a main transformer body, an online monitoring device of dissolved gas in oil, a four-way switching valve, a dynamic preparation of a standard oil sample device for characteristic gas components and a control module, wherein the online monitoring device of dissolved gas in oil is installed next to the main transformer body, and its oil sampling tube extends into the main transformer body, and a four-way switching valve is installed on the oil sampling tube, and the first channel of the four-way switching valve is connected to the online monitoring device of dissolved gas in oil through the oil sampling tube, the second channel is connected to the dynamic preparation of a standard oil sample device for characteristic gas components, the third channel is connected to the main transformer body through the oil sampling tube, and the fourth channel is connected to an external discharge barrel; the control module is electrically connected to the online monitoring device of dissolved gas in oil, the four-way switching valve, and the dynamic preparation of a standard oil sample device for characteristic gas components, respectively, to control the coordinated work of each part.

[0005] Furthermore, components including windings, iron cores, and high-voltage leads are installed inside the main transformer body and filled with transformer oil so as to insulate these components through the transformer oil; when overheating or discharge fault occurs inside the main transformer, high-temperature or high-energy discharge occurs at the fault point, causing the transformer oil around the fault point to crack and produce fault characteristic gas, wherein the fault characteristic gas is partially dissolved in the transformer oil, and the more gas cracked, the more gas is dissolved in the transformer oil; the online monitoring device for dissolved gas in oil analyzes the concentration of each component of the fault characteristic gas in the transformer oil online, thereby discovering the overheating or discharge fault occurring inside the main transformer, and judging the fault type and development trend.

[0006] Furthermore, the online monitoring device for dissolved gas in oil is a gas chromatograph or a spectrometer, which is equipped with an electrochemical sensor, a semiconductor detector, a thermal conductivity detector or a photoacoustic detector to detect the concentration of each component of the fault characteristic gas in the transformer oil.

[0007] Furthermore, the dynamic preparation of characteristic gas component standard oil sample device includes multiple single-component dynamic piston cylinders and a mixed sample cylinder. The multiple single-component dynamic piston cylinders are connected in parallel through a parallel connecting tube and are connected to the input end of the mixed sample cylinder. The output end of the mixed sample cylinder is connected to the second channel of the four-way switching valve. The output end of the single-component dynamic piston cylinder and the input end and output end of the mixed sample cylinder are all provided with oil outlet solenoid valves.

[0008] Furthermore, the device for dynamically preparing characteristic gas component standard oil samples includes eight single-component dynamic piston cylinders, wherein the first to seventh single-component dynamic piston cylinders are respectively pre-installed with single-component oil samples containing known high-concentration standard characteristic gases, namely: the first: a dynamic piston cylinder containing a known high-concentration hydrogen oil sample; the second: a dynamic piston cylinder containing a known high-concentration methane oil sample; the third: a dynamic piston cylinder containing a known high-concentration ethane oil sample; the fourth: a dynamic piston cylinder containing a known high-concentration ethylene oil sample; the fifth: a dynamic piston cylinder containing a known high-concentration acetylene oil sample; the sixth: a dynamic piston cylinder containing a known high-concentration carbon monoxide oil sample; the seventh: a dynamic piston cylinder containing a known high-concentration carbon dioxide oil sample; the eighth single-component dynamic piston cylinder is a dynamic piston cylinder pre-installed with a pure transformer oil sample.

[0009] Furthermore, the single-component dynamic piston cylinder includes a cylinder body, a piston and a driving device, and the driving device is connected to the piston to drive the piston to move back and forth in the cylinder body.

[0010] Furthermore, the driving device includes a micro-driving motor, a driving gear and a driving rack structure. The front end of the driving rack structure is fixedly connected to the rear end of the piston, and the output end of the micro-driving motor is fixedly connected to the driving gear, so that the forward and reverse rotation of the motor drives the forward and reverse rotation of the driving gear, and then the driving gear drives the driving rack structure and the piston to move forward and backward.

[0011] Furthermore, the dynamic preparation characteristic gas component standard oil sample device is also equipped with an ultrasonic device, which includes an ultrasonic generator and a miniature ultrasonic vibrator. The miniature ultrasonic vibrator is installed on the lower side wall of the mixing and sampling cylinder and connected to the ultrasonic generator to perform ultrasonic oscillation on the mixed oil sample in the cylinder to make it evenly mixed.

[0012] Furthermore, the comparison and calibration device also includes an alarm, and the control module is electrically connected to the online monitoring device for dissolved gas in oil, the four-way switching valve, the alarm, each oil outlet solenoid valve, each micro drive motor, and the ultrasonic generator, respectively, to control the operation of the online monitoring device for dissolved gas in oil and obtain its detection data, control the switching channel of the four-way switching valve, control the device to alarm, control the switching of each oil outlet solenoid valve, control the operation of each micro drive motor, and control the operation of the ultrasonic generator.

[0013] The present invention also provides a comparison and calibration method for an online monitoring device for dissolved gas in main transformer oil based on the above comparison and calibration device, characterized in that oil samples containing various known high-concentration standard characteristic gas single components and pure transformer oil samples are pre-installed in each single-component dynamic piston cylinder of the device for dynamically preparing characteristic gas component standard oil samples, and then the online monitoring device for dissolved gas in oil is compared and calibrated according to the following steps:

[0014] 1) Switch the four-way switching valve to connect the third channel and the fourth channel, and flush the pipeline with the transformer oil in the main transformer body; after flushing the pipeline, switch the four-way switching valve to connect the first channel and the third channel;

[0015] 2) Turn on the online monitoring device for dissolved gas in oil and draw transformer oil samples from the main transformer body;

[0016] 3) The online monitoring device for dissolved gas in oil detects the transformer oil sample taken, and sends the detection data of the concentration of each characteristic gas component obtained by the detection to the control module;

[0017] 4) The control module automatically controls the dynamic preparation of characteristic gas component standard oil sample device according to the detection data to prepare a mixed oil sample with the same component concentration;

[0018] 5) Switch the four-way switching valve to connect the second channel and the fourth channel, open the oil outlet solenoid valve of the mixed sample preparation cylinder of the dynamic preparation characteristic gas component standard oil sample device, and flush the pipeline with the mixed oil sample in the mixed sample preparation cylinder; then, close the oil outlet solenoid valve of the mixed sample preparation cylinder, and discharge the flushing oil to the external discharge barrel through the fourth channel;

[0019] 6) Turn on the online monitoring device for dissolved gas in oil, and then switch the four-way switching valve to connect the first channel and the second channel; then, open the oil outlet solenoid valve of the mixed sample preparation cylinder, and after the online monitoring device for dissolved gas in oil absorbs the mixed oil sample in the mixed sample preparation cylinder, close the oil outlet solenoid valve of the mixed sample preparation cylinder;

[0020] 7) The online monitoring device for dissolved gas in oil detects the mixed oil sample. If the difference between the detection data and the detection data in step 3) is within the allowable range, it means that the detection data of the online monitoring device for dissolved gas in oil is accurate. Otherwise, it means that the detection of the online monitoring device for dissolved gas in oil is inaccurate and the device alarms.

[0021] 8) Use the mixed oil sample of known concentration in the mixed sample tube to compare and calibrate the online monitoring device for dissolved gas in oil, so that its detection error is restored to the allowable range, and then turn off the online monitoring device for dissolved gas in oil;

[0022] 9) Switch the four-way switching valve to connect the second channel and the fourth channel, open the oil outlet solenoid valve of the mixed sample preparation cylinder and the single-component dynamic piston cylinder pre-installed with pure transformer oil sample, and clean the pipeline with pure transformer oil sample; then, close the dynamic preparation of characteristic gas component standard oil sample device;

[0023] 10) The comparison and calibration of the online monitoring device for dissolved gas in oil is completed.

[0024] Compared with the prior art, the present invention has the following beneficial effects: the present invention designs and develops a device and method for online comparison and calibration of an online monitoring device for dissolved gas in oil of a large power transformer using a device for dynamically preparing a characteristic gas component standard oil sample, which can quickly prepare a mixed oil sample of similar concentration according to the component content of characteristic gas generated when an overheating or discharge fault occurs inside the large power transformer, and can quickly and accurately analyze and compare the online monitoring device for dissolved gas in oil, thus overcoming the shortcomings of the use of the traditional online monitoring device for dissolved gas in oil of the main transformer, and effectively ensuring the safe operation of the large power transformer. Therefore, the present invention has strong practicality and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 2 is a schematic structural diagram of a comparison and calibration device for an online monitoring device for dissolved gas in main transformer oil according to an embodiment of the present invention;

[0026] Figure 2 2 is a schematic diagram of the structure of a device for dynamically preparing a standard oil sample of characteristic gas components in an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of the structure of a single-component dynamic piston cylinder in an embodiment of the present invention;

[0028] Figure 4 2 is a schematic diagram of the structure of a mixing and sample preparation cartridge according to an embodiment of the present invention;

[0029] Figure 5 It is a control principle block diagram of the control module in an embodiment of the present invention.

[0030] In the figure: 1-main transformer body; 2-winding; 3-transformer oil; 4-device for dynamically preparing standard oil samples of characteristic gas components; 5-ultrasonic generator; 6-online monitoring device for dissolved gas in oil; 7-four-way switching valve; 8-first channel of four-way switching valve; 9-second channel of four-way switching valve; 10-third channel of four-way switching valve; 11-fourth channel of four-way switching valve; 12-exhaust barrel; 131-dynamic piston cylinder containing oil sample with known high concentration of hydrogen; 132-dynamic piston cylinder containing oil sample with known high concentration of methane; 133-dynamic piston cylinder containing oil sample with known high concentration of ethane; 134-dynamic piston cylinder containing oil sample with known high concentration of ethylene; 135-dynamic piston cylinder containing oil sample with known high concentration of hydrogen; Dynamic piston cylinder containing acetylene oil sample with known high concentration; 136-dynamic piston cylinder containing oil sample with known high concentration of carbon monoxide; 137-dynamic piston cylinder containing oil sample with known high concentration of carbon dioxide; 138-dynamic piston cylinder pre-installed with pure transformer oil sample; 14-dynamic piston cylinder oil outlet solenoid valve; 15-parallel connecting pipe; 16-oil outlet solenoid valve at the input end of the mixed sample cylinder; 17-mixed sample cylinder; 18-micro ultrasonic vibrator; 19-oil outlet solenoid valve at the output end of the mixed sample cylinder; 20-micro drive motor; 21-drive gear; 22-drive rack structure; 23-single component oil sample containing known high concentration of standard characteristic gas; 24-configured mixed oil sample with known concentration; 25-ultrasound. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] like Figure 1As shown, this embodiment provides a comparison and calibration device for an online monitoring device for dissolved gas in oil of a main transformer, comprising a main transformer body 1, an online monitoring device for dissolved gas in oil 6, a four-way switching valve 7, a dynamic preparation of a characteristic gas component standard oil sample device 4 and a control module, wherein the online monitoring device for dissolved gas in oil 6 is installed beside the main transformer body 1, and its oil sampling tube extends into the main transformer body, and a four-way switching valve 7 is installed on the part of the oil sampling tube outside the main transformer body, and the first channel 8 of the four-way switching valve 7 is connected to the online monitoring device for dissolved gas in oil 6 through the oil sampling tube, the second channel 9 is connected to the dynamic preparation of a characteristic gas component standard oil sample device 4, the third channel 10 is connected to the main transformer body 1 through the oil sampling tube, and the fourth channel 11 is connected to an external discharge barrel 12. The control module is electrically connected to the online monitoring device for dissolved gas in oil, the four-way switching valve, and the dynamic preparation of a characteristic gas component standard oil sample device, respectively, to control the coordinated work of each part.

[0035] The main transformer body 1 is internally installed with components including windings 2, iron cores, and high-voltage leads and is filled with transformer oil 3 to insulate these components through the transformer oil; when overheating or discharge fault occurs inside the main transformer, high-temperature or high-energy discharge occurs at the fault point, causing the transformer oil around the fault point to crack and produce fault characteristic gases such as hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, and carbon dioxide. The fault characteristic gases are partially dissolved in the transformer oil, and the more gas is cracked, the more gas is dissolved in the transformer oil; the online monitoring device for dissolved gas in oil analyzes the concentration of each component of the fault characteristic gas in the transformer oil online, thereby discovering the overheating or discharge fault inside the main transformer and judging the fault type and development trend.

[0036] In this embodiment, the online monitoring device for dissolved gas in oil can be a gas chromatograph or a spectrometer, which is equipped with an electrochemical sensor, a semiconductor detector, a thermal conductivity detector or a photoacoustic detector, etc., to detect the concentration of each component of the fault characteristic gas in the transformer oil.

[0037] like Figure 2-4 As shown, the dynamic preparation characteristic gas component standard oil sample device 4 includes a plurality of single-component dynamic piston cylinders and a mixed sample cylinder 17. The plurality of single-component dynamic piston cylinders are connected in parallel through a parallel connecting tube 15 and are connected to the input end of the mixed sample cylinder 17. The output end of the mixed sample cylinder 17 is connected to the second channel 9 of the four-way switching valve 7. The output end of the single-component dynamic piston cylinder and the input end and output end of the mixed sample cylinder are all provided with oil outlet solenoid valves.

[0038] like Figure 2As shown, in this embodiment, the dynamic preparation characteristic gas component standard oil sample device 4 includes eight single-component dynamic piston cylinders 131-138, wherein the first to seventh single-component dynamic piston cylinders 131-137 are respectively pre-installed with single-component oil samples containing known high concentrations of standard characteristic gases, namely: the first: a dynamic piston cylinder 131 containing a known high concentration hydrogen oil sample; the second: a dynamic piston cylinder 132 containing a known high concentration methane oil sample; the third: a dynamic piston cylinder 133 containing a known high concentration ethane oil sample; the fourth: a dynamic piston cylinder 134 containing a known high concentration ethylene oil sample; the fifth: a dynamic piston cylinder 135 containing a known high concentration acetylene oil sample; the sixth: a dynamic piston cylinder 136 containing a known high concentration carbon monoxide oil sample; the seventh: a dynamic piston cylinder 137 containing a known high concentration carbon dioxide oil sample; the eighth single-component dynamic piston cylinder is a dynamic piston cylinder 138 pre-installed with a pure transformer oil sample (i.e., only transformer oil does not contain the above-mentioned other components).

[0039] like Figure 3 As shown, the single-component dynamic piston cylinder includes a cylinder body, a piston and a driving device, and the driving device is connected to the piston to drive the piston to move forward and backward in the cylinder body. In this embodiment, the driving device includes a micro-drive motor 20, a drive gear 21 and a drive rack structure 22, the front end of the drive rack structure 22 is fixedly connected to the rear end of the piston, and the output end of the micro-drive motor 20 is fixedly connected to the drive gear 21, so that the forward and reverse rotation of the motor 20 drives the forward and reverse rotation of the drive gear 21, and then the drive gear 21 drives the drive rack structure 22 and the piston to move forward and backward.

[0040] like Figure 4 As shown, the dynamic preparation characteristic gas component standard oil sample device is also equipped with an ultrasonic device, which includes an ultrasonic generator 5 and a miniature ultrasonic vibrator 18. The miniature ultrasonic vibrator 18 is installed on the lower side wall of the mixing sample cylinder 17 and is connected to the ultrasonic generator 5 to perform ultrasonic oscillation on the mixed oil sample in the cylinder to make it evenly mixed.

[0041] In this embodiment, each single-component dynamic piston cylinder is made of high-quality polytetrafluoroethylene material and is cylindrical, and an oil outlet solenoid valve is installed in the center of the end of the cylinder. The mixed sample cylinder is made of high-quality polytetrafluoroethylene material and is also cylindrical, and an oil outlet micro solenoid valve is also installed in the center of its bottom. The upper part of the mixed sample cylinder is connected to one side of the parallel connecting pipe through the oil outlet solenoid valve, and the other side of the parallel connecting pipe is connected in parallel to the oil outlet solenoid valves of the first to eighth dynamic piston cylinders, and the two ends of the parallel connecting pipe are sealed. The oil samples in the first to eighth dynamic piston cylinders first enter the parallel connecting pipe through the oil outlet solenoid valve at the end, and then enter the mixed sample cylinder through the oil outlet micro solenoid valve of the parallel connecting pipe to prepare the standard mixed oil sample. The ultrasonic oscillator installed on the lower side wall of the mixed sample cylinder performs ultrasonic oscillation and uniform mixing on the mixed oil sample entering the cylinder, and the micro ultrasonic vibrator is connected to the nearby external ultrasonic generator through a connecting line.

[0042] The comparison and calibration device also includes an alarm. Figure 5 As shown, the control module is electrically connected to the online monitoring device for dissolved gas in oil, the four-way switching valve, the alarm, each oil outlet solenoid valve, each micro drive motor, and the ultrasonic generator, respectively, to control the operation of the online monitoring device for dissolved gas in oil and obtain its detection data, control the switching channel of the four-way switching valve, control the device to alarm, control the switch of each oil outlet solenoid valve, control the operation of each micro drive motor, and control the operation of the ultrasonic generator.

[0043] The working principle of dynamic preparation of this device is as follows: after receiving the signal from the control module that a mixed component concentration oil sample needs to be prepared, the dynamic preparation device for characteristic gas component standard oil sample will inject the oil samples containing known single-component special gas concentrations and pure oil products in the first to eighth dynamic piston cylinders into the mixed sample preparation cylinder through parallel connecting pipes according to the pre-prepared known high-concentration single-component characteristic gases in proportion, and then the online monitoring device for dissolved gas in oil will perform chromatographic analysis on the oil samples with known characteristic gas component concentrations prepared in the mixed sample preparation cylinder. If the test result is within the allowable error range of the known oil sample data, it means that the online monitoring device for dissolved gas in oil is accurate. If it is outside the error range, the online monitoring device for dissolved gas in oil needs to be re-compared and calibrated according to the oil samples with known characteristic gas component concentrations.

[0044] The control module is pre-programmed with: 1) setting the error range of the online monitoring device for dissolved gas in oil to perform a test on the main transformer body oil and the comparison of the test data of the oil sample with known component concentration configured by the dynamic preparation of the characteristic gas component standard oil sample device. When the comparison error exceeds the setting, the online monitoring device for dissolved gas in oil is compared and calibrated according to the data of the prepared standard mixed oil sample containing the characteristic gas with known concentration; 2) controlling the control program of each solenoid valve and drive motor in the dynamic preparation of the characteristic gas component standard oil sample device. The output end of the online monitoring device for dissolved gas in oil is electrically connected to the input end of the control module, and the output end of the control module is electrically connected to: the input end of each micro solenoid valve, the input end of each micro motor driver, the input end of the alarm, the input end of the ultrasonic generator, etc. The output end of the control module is also fed back and electrically connected to the input end of the online monitoring device for dissolved gas in oil, which is used to control the calibration of the online monitoring device for dissolved gas in oil when the detection data error exceeds the setting range.

[0045] The online monitoring device for dissolved gas in oil sends the data of the content of each characteristic gas component dissolved in the transformer oil to the control module. The control module analyzes and diagnoses the content of each characteristic gas component detected by the online monitoring device for dissolved gas in oil according to the pre-set and programmed diagnostic program, thereby determining the type, severity and development trend of the main transformer failure. When it is necessary to compare and calibrate the online monitoring device for dissolved gas in oil, a characteristic gas oil sample with a known concentration of a standard gas component is dynamically prepared through a dynamic preparation device, and a characteristic gas oil sample with a known standard component concentration is dynamically prepared, and the online monitoring device for dissolved gas in oil is dynamically calibrated and compared.

[0046] This embodiment also provides a comparison and calibration method for the main transformer oil dissolved gas online monitoring device based on the above comparison and calibration device. Oil samples containing various known high-concentration standard characteristic gas single components and pure transformer oil samples are pre-installed in each single-component dynamic piston cylinder of the dynamic preparation characteristic gas component standard oil sample device, and then the oil dissolved gas online monitoring device is compared and calibrated according to the following steps:

[0047] 1) Switch the four-way switching valve 7 to connect the third channel 10 and the fourth channel 11, and flush the pipeline with the transformer oil 3 in the main transformer body 1; after flushing the pipeline, switch the four-way switching valve 7 to connect the first channel 8 and the third channel 10.

[0048] 2) Turn on the online monitoring device 6 for dissolved gas in oil and absorb the transformer oil sample in the main transformer body 1.

[0049] 3) The online monitoring device 6 for dissolved gas in oil detects the transformer oil sample taken, and sends the detection data of the concentration of each characteristic gas component obtained by the detection to the control module.

[0050] 4) The control module automatically controls the dynamic preparation of characteristic gas component standard oil sample device according to the detection data to prepare a mixed oil sample with the same component concentration. The specific preparation process is as follows:

[0051] 4.1) The oil outlet solenoid valve 14 of the first oil sample dynamic piston cylinder 131 and the oil outlet solenoid valve 16 of the parallel connection pipe 15 are opened respectively. The control module starts the first drive motor 20 according to the test data of the concentration of hydrogen components contained in the main transformer body oil sample detected by the online monitoring device for dissolved gas in oil. The drive motor 20 drives the piston to compress, and quantitatively injects the oil sample with high concentration of hydrogen in the first oil sample dynamic piston cylinder 131 through the first oil outlet solenoid valve 14, the parallel connection pipe 15, and the oil outlet solenoid valve 16 into the mixed sample cylinder 17. After the quantitative injection, the first oil outlet solenoid valve 14 and the first drive motor 20 are closed;

[0052] 4.2) Similarly, the oil outlet solenoid valves and drive motors of the second to seventh oil sample dynamic piston cylinders 132-137 are opened respectively. The control module starts the second to seventh drive motors respectively according to the test data of the concentration of components such as methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, etc. contained in the main transformer body oil sample detected by the online monitoring device for dissolved gas in oil, and the oil samples with high concentration of gas contained in the second to seventh oil sample dynamic piston cylinders 132-137 are quantitatively injected into the mixed sample cylinder 17 through the second to seventh oil outlet solenoid valves, parallel connecting pipes 15 and oil outlet solenoid valves 16. After each quantitative oil injection work is completed, the corresponding oil outlet solenoid valves and drive motors are closed at the same time;

[0053] 4.3) Open the eighth oil outlet solenoid valve and the eighth drive motor of the eighth oil sample dynamic piston cylinder 138, and quantitatively inject the pure transformer oil in the eighth oil sample dynamic piston cylinder 138 into the mixed sample cylinder 17 through the eighth oil outlet solenoid valve, the parallel connection pipe 15, and the oil outlet solenoid valve 16, and close the eighth oil outlet solenoid valve, the eighth drive motor, and the oil outlet solenoid valve 16;

[0054] 4.4) Start the micro ultrasonic generator 5, and the micro ultrasonic vibrator 18 installed in the mixing sample tube 17 oscillates the mixed oil sample. After the mixed oil sample is evenly mixed, turn off the ultrasonic generator 5 and stop the mixing oscillation. At this time, the standard mixed oil sample 24 has been prepared;

[0055] 5) Switch the four-way switching valve 7 to connect the second channel 9 and the fourth channel 11, open the oil outlet solenoid valve 19 of the mixed sample cylinder 17 of the dynamic preparation device of the characteristic gas component standard oil sample, and flush the pipeline with the mixed oil sample 24 in the mixed sample cylinder; then, close the oil outlet solenoid valve 19 of the mixed sample cylinder, and discharge the flushing oil to the external discharge barrel 12 through the fourth channel 11.

[0056] 6) Open the online monitoring device for dissolved gas in oil 6, and then switch the four-way switching valve 7 to connect the first channel 8 and the second channel 9; then, open the oil outlet solenoid valve 19 of the mixed sample cylinder, and after the online monitoring device for dissolved gas in oil 6 absorbs the mixed oil sample 24 in the mixed sample cylinder, close the oil outlet solenoid valve 19 of the mixed sample cylinder.

[0057] 7) The online monitoring device for dissolved gas in oil 6 detects the mixed oil sample 24. If the difference between the detection data and the detection data in step 3) is within the allowable range, it means that the detection data of the online monitoring device for dissolved gas in oil 6 is accurate. Otherwise, it means that the detection of the online monitoring device for dissolved gas in oil is inaccurate and the device alarms.

[0058] 8) Use the mixed oil sample 24 of known concentration in the mixed sample tube 17 to compare and calibrate the online monitoring device for dissolved gas in oil, so that its detection error is restored to the allowable range, and then close the online monitoring device for dissolved gas in oil 6.

[0059] 9) Switch the four-way switching valve 7 to connect the second channel 9 and the fourth channel 11, open the oil outlet solenoid valve 19 of the mixed sample cylinder and the single-component dynamic piston cylinder pre-installed with pure transformer oil sample, and clean the pipeline with pure transformer oil sample; then, close the dynamic preparation of characteristic gas component standard oil sample device.

[0060] 10) The comparison and calibration of the online monitoring device for dissolved gas in oil is completed.

[0061] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A comparison and calibration device for an online monitoring device for dissolved gas in main transformer oil, characterized in that: It includes a main transformer body, an online monitoring device for dissolved gas in oil, a four-way switching valve, a dynamic preparation of a characteristic gas component standard oil sample device and a control module. The online monitoring device for dissolved gas in oil is installed beside the main transformer body, and its oil sampling tube extends into the main transformer body. The four-way switching valve is installed on the oil sampling tube. The first channel of the four-way switching valve is connected to the online monitoring device for dissolved gas in oil through the oil sampling tube, the second channel is connected to the dynamic preparation of a characteristic gas component standard oil sample device, the third channel is connected to the main transformer body through the oil sampling tube, and the fourth channel is connected to the external discharge barrel; the control module is electrically connected to the online monitoring device for dissolved gas in oil, the four-way switching valve, and the dynamic preparation of a characteristic gas component standard oil sample device, respectively, to control the coordinated work of each part; The main transformer body is internally installed with components including windings, iron cores, and high-voltage leads and filled with transformer oil to insulate these components through the transformer oil; when an overheating or discharge fault occurs inside the main transformer, a high-temperature or high-energy discharge phenomenon is generated at the fault point, causing the transformer oil around the fault point to crack and generate fault characteristic gas, wherein the fault characteristic gas is partially dissolved in the transformer oil, and the more cracked gas is, the more the content dissolved in the transformer oil is; the online monitoring device for dissolved gas in oil analyzes the concentration of each component of the fault characteristic gas in the transformer oil online, thereby discovering the overheating or discharge fault occurring inside the main transformer, and judging the fault type and development trend; The dynamic preparation characteristic gas component standard oil sample device includes multiple single-component dynamic piston cylinders and a mixed sample cylinder. The multiple single-component dynamic piston cylinders are connected in parallel through a parallel connecting tube and are connected to the input end of the mixed sample cylinder. The output end of the mixed sample cylinder is connected to the second channel of the four-way switching valve. The output end of the single-component dynamic piston cylinder and the input end and output end of the mixed sample cylinder are all provided with oil outlet solenoid valves.

2. The comparison and calibration device for the online monitoring device for dissolved gas in main transformer oil according to claim 1 is characterized in that: The on-line monitoring device for dissolved gas in oil is a gas chromatograph or a spectrometer, which is equipped with an electrochemical sensor, a semiconductor detector, a thermal conductivity detector or a photoacoustic detector to detect the concentration of each component of the fault characteristic gas in the transformer oil.

3. The comparison and calibration device for the online monitoring device of dissolved gas in main transformer oil according to claim 1 is characterized in that: The dynamic preparation characteristic gas component standard oil sample device comprises eight single-component dynamic piston cylinders, wherein the first to seventh single-component dynamic piston cylinders are respectively pre-installed with known high-concentration standard characteristic gas single-component oil samples, namely: the first: a dynamic piston cylinder containing a known high-concentration hydrogen oil sample; the second: a dynamic piston cylinder containing a known high-concentration methane oil sample; the third: a dynamic piston cylinder containing a known high-concentration ethane oil sample; the fourth: a dynamic piston cylinder containing a known high-concentration ethylene oil sample; The fifth one: a dynamic piston cylinder containing an oil sample with a known high concentration of acetylene; The sixth one: a dynamic piston cylinder containing an oil sample with a known high concentration of carbon monoxide; The seventh one: a dynamic piston cylinder containing a known high-concentration carbon dioxide oil sample; the eighth single-component dynamic piston cylinder is a dynamic piston cylinder pre-installed with a pure transformer oil sample.

4. The comparison and calibration device for the online monitoring device for dissolved gas in main transformer oil according to claim 1 is characterized in that: The single-component dynamic piston cylinder comprises a cylinder body, a piston and a driving device, wherein the driving device is connected to the piston to drive the piston to move back and forth in the cylinder body.

5. The comparison and calibration device for the online monitoring device for dissolved gas in main transformer oil according to claim 4 is characterized in that: The driving device includes a micro-driving motor, a driving gear and a driving rack structure. The front end of the driving rack structure is fixedly connected to the rear end of the piston, and the output end of the micro-driving motor is fixedly connected to the driving gear, so that the forward and reverse rotation of the motor drives the forward and reverse rotation of the driving gear, and then the driving gear drives the driving rack structure and the piston to move forward and backward.

6. The comparison and calibration device for the online monitoring device for dissolved gas in main transformer oil according to claim 5 is characterized in that: The dynamic preparation characteristic gas component standard oil sample device is also equipped with an ultrasonic device, which includes an ultrasonic generator and a micro ultrasonic vibrator. The micro ultrasonic vibrator is installed on the lower side wall of the mixing and sampling cylinder and is connected to the ultrasonic generator to perform ultrasonic oscillation on the mixed oil sample in the cylinder to make it mixed evenly.

7. The comparison and calibration device for the online monitoring device for dissolved gas in main transformer oil according to claim 6 is characterized in that: The comparison and calibration device also includes an alarm. The control module is electrically connected to the online monitoring device for dissolved gas in oil, the four-way switching valve, the alarm, each oil outlet solenoid valve, each micro drive motor, and the ultrasonic generator, respectively, to control the operation of the online monitoring device for dissolved gas in oil and obtain its detection data, control the switching channel of the four-way switching valve, control the device to alarm, control the switching of each oil outlet solenoid valve, control the operation of each micro drive motor, and control the operation of the ultrasonic generator.

8. A comparison and calibration method of an online monitoring device for dissolved gas in main transformer oil based on the device according to any one of claims 1 to 7, characterized in that: Pre-install oil samples containing various known high-concentration standard characteristic gas single components and pure transformer oil samples in each single-component dynamic piston cylinder of the dynamic preparation characteristic gas component standard oil sample device, and then perform comparison and calibration on the online monitoring device for dissolved gas in oil according to the following steps: 1) Switch the four-way switching valve to connect the third channel and the fourth channel, and flush the pipeline with the transformer oil in the main transformer body; after flushing the pipeline, switch the four-way switching valve to connect the first channel and the third channel; 2) Turn on the online monitoring device for dissolved gas in oil and draw transformer oil samples from the main transformer body; 3) The online monitoring device for dissolved gas in oil detects the transformer oil sample taken, and sends the detection data of the concentration of each characteristic gas component obtained by the detection to the control module; 4) The control module automatically controls the dynamic preparation of characteristic gas component standard oil sample device according to the detection data to prepare a mixed oil sample with the same component concentration; 5) Switch the four-way switching valve to connect the second channel and the fourth channel, open the oil outlet solenoid valve of the mixed sample preparation cylinder of the dynamic preparation characteristic gas component standard oil sample device, and flush the pipeline with the mixed oil sample in the mixed sample preparation cylinder; then, close the oil outlet solenoid valve of the mixed sample preparation cylinder, and discharge the flushing oil to the external discharge barrel through the fourth channel; 6) Turn on the online monitoring device for dissolved gas in oil, and then switch the four-way switching valve to connect the first channel and the second channel; then, open the oil outlet solenoid valve of the mixed sample preparation cylinder, and after the online monitoring device for dissolved gas in oil absorbs the mixed oil sample in the mixed sample preparation cylinder, close the oil outlet solenoid valve of the mixed sample preparation cylinder; 7) The online monitoring device for dissolved gas in oil detects the mixed oil sample. If the difference between the detection data and the detection data in step 3) is within the allowable range, it means that the detection data of the online monitoring device for dissolved gas in oil is accurate. Otherwise, it means that the detection of the online monitoring device for dissolved gas in oil is inaccurate and the device alarms. 8) Use the mixed oil sample of known concentration in the mixed sample tube to compare and calibrate the online monitoring device for dissolved gas in oil, so that its detection error is restored to the allowable range, and then turn off the online monitoring device for dissolved gas in oil; 9) Switch the four-way switching valve to connect the second channel and the fourth channel, open the oil outlet solenoid valve of the mixed sample preparation cylinder and the single-component dynamic piston cylinder pre-installed with pure transformer oil sample, and clean the pipeline with pure transformer oil sample; then, close the dynamic preparation of characteristic gas component standard oil sample device; 10) The comparison and calibration of the online monitoring device for dissolved gas in oil is completed.

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