Standard oil verification device and method for transformer oil chromatography on-line monitoring

Abstract

The invention relates to the technical field of transformer oil chromatography detection, in particular to a standard oil verification device and method for transformer oil chromatography online monitoring. A mobile platform is used for bearing an oil tank, a control unit and a detection unit; the oil tank is used for storing standard oil samples with different concentrations and is provided with a control valve; the detection unit comprises an off-line oil chromatography detection device and a to-be-detected on-line oil chromatography detection device, and is used for outputting a detection result according to a standard oil sample in an oil tank and sending the detection result to the control unit; the control unit is used for sequentially sending standard oil samples with different concentrations into the detection unit through a control valve, and verifying the reliability of the online monitoring device by comparing detection results output by the offline oil chromatography detection device and the online oil chromatography detection device. The oil chromatography online monitoring device can be verified in an automatic mode, manual oil sample switching and cleaning and related sample feeding, sample discharging and other operations in the traditional verification process are reduced, and therefore verification efficiency is improved.

Description

Technical Field

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

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

[0003] Oil-immersed transformers are transformers that use transformer oil as a cooling and insulating medium. Transformer oil will gradually deteriorate and deteriorate as the transformer is running. Therefore, it is necessary to regularly or irregularly inspect the quality of the transformer to master the performance of the transformer. Chromatographic detection is a common method. Before inputting the sample transformer oil for testing, it is necessary to calibrate the chromatographic detection instrument with a standard oil sample to ensure that the peaks of each component are normal. The inspection process requires that standard oil samples of different concentrations be sent to the chromatographic detection instrument. In order to obtain sufficient detection accuracy for the chromatographic detection instrument, multiple calibrations are often required, which is time-consuming. In addition, in some online monitoring operations of transformer oil, high-altitude operations and live-line operations may also be involved. There are risks in performing high-altitude operations and live-line operations for a long time. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a standard oil calibration device and method for online monitoring of transformer oil chromatography, which pre-configures standard oil samples of different concentrations and stores them in a storage container, realizes automatic switching sampling of transformer standard oil samples by controlling corresponding valves, and realizes calibration of the oil chromatography online monitoring device by comparing the data of the online monitoring device with the offline detection device.

[0005] In order to achieve the above object, the present invention adopts the following technical embodiments:

[0006] The first aspect of the present invention provides a standard oil calibration device for online monitoring of transformer oil chromatography, comprising:

[0007] Mobile platform for carrying oil tank, control unit and detection unit;

[0008] Oil tanks are used to store standard oil samples of different concentrations and are equipped with control valves;

[0009] The detection unit includes an offline oil chromatographic detection device and an online oil chromatographic detection device to be tested, and is used to output the detection result according to the standard oil sample in the oil tank and send it to the control unit;

[0010] The control unit is configured to: send standard oil samples of different concentrations into the detection unit in sequence through the control valve, compare the detection results output by the offline oil chromatography detection device and the online oil chromatography detection device in sequence, and if the error exceeds the set value, calibrate the online device according to the chromatogram peak data in the offline device detection data, and after the calibration is completed, switch to the next set of standard oil samples of concentration for verification.

[0011] Furthermore, the control unit includes a control module connected to the CPU, and the control module is configured to: send an action instruction to the control valve, switch the standard oil samples of different concentrations in the oil tank in turn, and send them to the online oil chromatography detection device and the offline oil chromatography detection device to be tested, so as to obtain the detection results corresponding to a group of standard oil samples of a certain concentration.

[0012] Further, the control unit also includes a verification module connected to the CPU, and the CPU receives and compares the detection results output by the online oil chromatography detection device and the offline oil chromatography detection device;

[0013] If the error exceeds the set value, the online device is calibrated using the calibration module based on the chromatogram peak data in the offline device detection data;

[0014] If the error does not exceed the set value, the control module switches to the next set of standard oil samples of concentration to continue calibration.

[0015] Furthermore, the control unit also includes a communication module connected to the CPU, which is used to communicate with the communication device and transmit the data results during the verification period.

[0016] Furthermore, the control valve and the off-line oil chromatography detection device, as well as the control valve and the on-line oil chromatography detection device to be tested are respectively connected through pipelines.

[0017] Furthermore, the mobile platform is a motor vehicle.

[0018] A second aspect of the present invention provides a standard oil calibration method for online monitoring of transformer oil chromatography, comprising the following steps:

[0019] A standard oil sample of the required concentration is prepared in advance and stored in an oil tank. The control valve of the oil tank is connected to the online oil chromatography monitoring device to be tested through a pipeline, and the control valve is connected to the offline oil chromatography monitoring device through a pipeline;

[0020] Exhaust and flush the residual oil left over from the last test in the online oil chromatography monitoring device to be tested;

[0021] The offline oil chromatogram monitoring device is connected to the online oil chromatogram monitoring device to be tested by communication, and the same set of standard oil samples are tested and the obtained output data are used for comparison. If the error exceeds the set value, the online oil chromatogram monitoring device is calibrated according to the chromatogram peak data in the test data of the offline oil chromatogram monitoring device; if the error does not exceed the set value, the next set of standard oil samples of the concentration is switched to continue the calibration;

[0022] When the calibration of the standard oil sample of the current concentration is completed, a trigger signal is issued to switch to the next set of standard oil samples of the concentration for calibration until the calibration of the standard oil samples of all concentrations is completed.

[0023] Furthermore, a standard oil sample of a desired concentration is obtained by mixing the standard oil with characteristic gases having different component contents.

[0024] Furthermore, before the control valve of the oil tank is connected to the online oil chromatogram monitoring device to be tested through a pipeline, the network connection of the online oil chromatogram monitoring device to be tested and the oil circuit connection with the transformer are disconnected.

[0025] Furthermore, the online device verification was completed, the field equipment connection was restored, the pipeline was flushed with the original transformer oil and the network connection was restored.

[0026] Compared with the prior art, one or more of the above technical embodiments have the following beneficial effects:

[0027] By pre-configuring standard oil samples of different concentrations and storing them in storage containers, the mobile platform carrying all the components arrives at the transformer site, and then automatically switching the transformer standard oil samples is achieved by controlling the valves corresponding to the containers. The data of the online monitoring device and the offline detection device corresponding to each group of standard oil samples of concentration are compared in turn to verify the reliability of the online monitoring device and perform calibration. After the calibration is completed, the valve corresponding to the container is controlled to switch to the next group of standard oil samples of concentration for detection. Through multiple iterative detections, the calibration of the oil chromatography online monitoring device is achieved in an automated manner, which can reduce the manual switching, cleaning, and related injection and output operations of oil samples in the traditional calibration process, thereby improving the calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0029] Figure 1 A schematic diagram of the structure of a standard oil calibration device for online monitoring of transformer oil chromatography provided by one or more embodiments of the present invention;

[0030] Figure 2A schematic diagram of a standard oil calibration process for online monitoring of transformer oil chromatography provided by one or more embodiments of the present invention. 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 invention. 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 invention belongs.

[0033] As introduced in the background art, the calibration work involved in the chromatographic online monitoring of transformer oil is time-consuming, thereby amplifying the risks brought by the high-altitude and live-line work involved during the online monitoring.

[0034] Therefore, the following embodiments provide a standard oil calibration device and a working method for online monitoring of transformer oil chromatography, by pre-configuring standard oil samples of different concentrations and storing them in a storage container, using a controller and a control valve to realize automatic switching sampling of transformer standard oil samples, and by comparing the data of the online monitoring device with the offline detection device, the calibration of the oil chromatography online monitoring device is realized.

[0035] Embodiment 1:

[0036] like Figure 1 As shown, the standard oil calibration device for online monitoring of transformer oil chromatography includes:

[0037] Mobile platform for carrying oil tank, control unit and detection unit;

[0038] Oil tanks are used to store standard oil samples of different concentrations and are equipped with control valves;

[0039] The detection unit includes an offline oil chromatographic detection device and an online oil chromatographic detection device to be tested, and is used to output the detection result according to the standard oil sample in the oil tank and send it to the control unit;

[0040] The control unit is configured to: send standard oil samples of different concentrations into the detection unit in sequence through the control valve, compare the detection results output by the offline oil chromatography detection device and the online oil chromatography detection device in sequence, and if the error exceeds the set value, calibrate the online device according to the chromatogram peak data in the offline device detection data, and after the calibration is completed, switch to the next set of standard oil samples of concentration for verification.

[0041] The basic working principle of the calibration is the standard oil comparison calibration method. A gas with a fault characteristic concentration is prepared in advance and injected into the standard oil for mixing and modulation. Standard oil samples of different concentrations are obtained and stored in an oil tank. After the standard oil in the oil tank is tested by an oil chromatography online monitoring device, the analyzed fault characteristic gas data is compared with the calibration oil data to determine the reliability of the gas detection by the online monitoring device.

[0042] Among them, the calibration oil data is the data recorded when the standard oil is configured, which is objectively correct data. The fault characteristic gas data analyzed by the oil chromatography monitoring device will change with the environment in which the oil chromatography monitoring device is located, such as temperature and humidity, and the detection performance will change accordingly, which will cause errors. At this time, the calibration oil data is needed to calibrate the oil chromatography monitoring device.

[0043] Based on the above theoretical analysis, the current calibration method of online monitoring devices requires relevant staff to work on-site, manually input standard oils of different concentrations into the online test device through the oil inlet pipe and verify the gas components through on-site tests. This involves complicated operations such as preparation, metering, flushing, injection and output of standard oil samples.

[0044] In this embodiment, the control unit includes a control module, a test module and a communication module which are respectively connected to the CPU. The control module switches the standard oil samples of different concentrations in the oil tank by controlling the valve, and sends them to the online oil chromatography detection device and the offline oil chromatography detection device. The output detection results are compared. If they do not meet the requirements, they are sent to the CPU. The chromatogram peaks obtained by the two detection devices are compared by the verification module, and the calibration coefficient is calculated, so as to calibrate the coefficient of the online oil chromatography detection device. When the requirements are met, the next set of standard oil samples of concentration are calibrated, and the data during the verification is transmitted to the required communication equipment through the communication module.

[0045] The above device can realize automatic control. For example, the oil inlet pipe input can be switched autonomously through the control module. During the first standard oil detection, the instruction to start the operation of the device is transmitted to the CPU through the communication module. After a fixed concentration standard oil detection is completed, a trigger signal is sent through the control module. The signal acts on the control valve to control the control valve of the oil tank to switch to standard oil of other concentrations, and perform the calibration of the next set of standard oil of concentration. The action is repeated until all standard oils (standard oil samples) of various concentrations are detected, and a termination signal is sent to close the valve.

[0046] After controlling the input of standard oil, the standard oil is input into both online and offline devices at the same time, and the equipment accuracy is verified through data comparison.

[0047] The structures of the offline oil chromatography detection device and the online oil chromatography detection device can be the same or different. Both are devices in the prior art that use chromatography to detect the content of gas components in transformer oil. The specific structural type is not limited in this embodiment. The difference lies in the application scenarios of the two.

[0048] Offline oil chromatography detection devices are usually used in laboratories, and are usually calibrated or calibrated at regular intervals to maintain their detection accuracy. Online oil chromatography detection devices are used near transformers in operation on site. Oil in the transformer is usually forced to circulate and sampled for degassing by an oil pump, and the degassed gas is sent to the online oil chromatography detection device for online detection. Since the online oil chromatography detection device is located at the transformer operation site and operates in an electric environment or even a high-altitude environment for a long time, it is difficult to perform frequent accuracy calibration. Therefore, the accuracy of the offline detection device is more guaranteed. Therefore, this embodiment is used as a comparison device for the online monitoring device.

[0049] In this embodiment, the configured standard oils are stored in oil tanks respectively. When the calibration is performed, the standard oil samples of the same concentration are input into the online monitoring device and the offline detection device for detection respectively. After the calibration is completed, the results of each gas component are derived, and the two sets of result data are calculated for relative error to determine whether they meet the 30% error standard. If they do not meet the standard, the coefficient of the online device is calibrated according to the gas peak data in the chromatogram. The whole process does not require manual participation, which solves the problem of waste of human resources in traditional calibration work and realizes unmanned calibration of the chromatographic device.

[0050] In the above device, the online oil chromatography detection device in the detection unit is the target to be calibrated, and the remaining components are integrated on a mobile platform. The mobile platform is not limited to a specific structural type, for example, it can be a motor vehicle, so that the device forms a calibration vehicle, the calibration vehicle drives to the vicinity of the online oil chromatography detection device to be tested on site, connects the oil tank and the online oil chromatography detection device to be tested with a pipeline, and connects the control unit and the online oil chromatography detection device to be tested with a data cable, thereby realizing unmanned calibration of the online oil chromatography detection device to be tested, reducing the manual oil sample switching, cleaning and related sample injection and sample output operations in the traditional calibration process, thereby improving efficiency.

[0051] Embodiment 2:

[0052] like Figure 2 As shown, the standard oil calibration method for transformer oil chromatographic online monitoring includes the following steps:

[0053] Step 1: Prepare standard oil sample of required concentration and store it in oil tank.

[0054] The standard oil sample of required concentration is obtained by mixing standard oil + characteristic gas with different component contents.

[0055] Before preparation, it is necessary to ensure that the standard oil used for preparation has been vacuum degassed or eluted with 99.99% pure nitrogen, prepare the gas with fault characteristic concentration, inject it into the standard oil, mix and modulate it, and then store it in the oil tank. After the standard oil is prepared, it needs to be left to exhaust, and then the content of each gas component is determined according to the existing specifications, such as GB / T 17623-2017 "Gas Chromatography Determination of Dissolved Gas Component Content in Insulating Oil". The standard oil is transported to a fully sealed oil tank through the oil inlet pipe for storage. The storage environment should be cool and non-humid. The standard oil should not be stored for too long after preparation. For example, it needs to be re-determined if it exceeds 1 week;

[0056] Step 2: Connect with the online oil chromatography monitoring device to be tested.

[0057] When conducting on-site operations for the calibration of the online oil chromatography monitoring device, disconnect the network connection and close the valve. Use oil pipes to connect the online monitoring device to this device, ensure that the inlet and outlet oil valves do not leak oil, and obtain a suitable power supply for the oil tank; when the mobile platform in this device is a motor vehicle, it forms a fully automatic calibration vehicle, and uses oil pipes to connect the online monitoring device to the fully automatic calibration vehicle.

[0058] Step 3: Exhaust and flush the residual oil left over from the previous test in the online oil chromatography monitoring device.

[0059] After power is taken off, the oil tank outlet switch is switched through the control module, and the oil in the oil tank flows into the air pipe to exhaust the air, so that the inlet and outlet oil pipes are free of impurities; because there is residual oil left in the oil chromatogram online monitoring equipment from the last transformer oil test, the internal pipeline of the device needs to be flushed with standard oil at least 3 times;

[0060] Step 4: Connect the offline oil chromatography monitoring device with the online oil chromatography monitoring device to be tested, detect the same set of standard oil samples through the online device and the offline device, and compare the obtained output data. If the error does not exceed the set value, switch to the next set of standard oil samples of concentration to continue the calibration. If the error exceeds the set value, calibrate the online device according to the chromatogram peak data in the offline device detection data.

[0061] For example, the oil chromatogram online monitoring equipment and the oil chromatogram offline monitoring equipment connected by computer software are set up with a calibration program to detect the standard oil concentration. After the calibration is completed, the software exports each gas component, calculates the relative error of the two sets of data obtained, and determines whether it meets the 30% error standard. If it meets the standard, it will be fed back to the central control for the next calibration; if it does not meet the standard, it will be fed back to the CPU to call up the chromatograms of the online device and the offline device, and calibrate the coefficient of the online device according to the gas peak data in the chromatogram.

[0062] Step 5: After the calibration of the standard oil sample of the current concentration is completed, a trigger signal is issued to switch to the next set of standard oil samples of the next concentration for calibration until the calibration of the standard oil samples of all concentrations is completed.

[0063] In this embodiment, after the fourth step is completed, the system determines the time at this time. When the time is greater than the set value, a trigger signal is sent to the internal control module, and the signal acts on the control valve to control the oil tank oil outlet switch to switch to other concentrations of standard oil, and repeat the third and fourth steps. Until all concentrations of standard oil are detected, the system sends a termination signal.

[0064] Step 6: After the online device verification is completed, restore the on-site equipment connection, use the original transformer oil to flush the pipeline and restore the equipment network connection.

[0065] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A standard oil calibration device for online monitoring of transformer oil chromatography, characterized in that: include: Mobile platform for carrying oil tank, control unit and detection unit; Oil tanks are used to store standard oil samples of different concentrations and are equipped with control valves; The detection unit includes an offline oil chromatographic detection device and an online oil chromatographic detection device to be tested, and is used to output the detection result according to the standard oil sample in the oil tank and send it to the control unit; The control unit is configured to: send standard oil samples of different concentrations into the detection unit in sequence through the control valve, compare the detection results output by the offline oil chromatography detection device and the online oil chromatography detection device in sequence, and if the error exceeds the set value, calibrate the online device according to the chromatogram peak data in the offline device detection data, and after the calibration is completed, switch to the next set of standard oil samples of concentration for verification.

2. The standard oil calibration device for online monitoring of transformer oil chromatography according to claim 1, characterized in that: The control unit includes a control module connected to the CPU, and the control module is configured to: send an action instruction to the control valve, switch the standard oil samples of different concentrations in the oil tank in turn, send them to the online oil chromatography detection device and the offline oil chromatography detection device to be tested, and obtain the detection results corresponding to a group of standard oil samples of a certain concentration.

3. The standard oil calibration device for online monitoring of transformer oil chromatography according to claim 1, characterized in that: The control unit also includes a verification module connected to the CPU, and the CPU receives and compares the detection results output by the online oil chromatography detection device and the offline oil chromatography detection device; If the error exceeds the set value, the online device is calibrated using the calibration module based on the chromatogram peak data in the offline device detection data; If the error does not exceed the set value, the control module switches to the next set of standard oil samples of concentration to continue calibration.

4. The standard oil calibration device for online monitoring of transformer oil chromatography according to claim 1, characterized in that: The control unit also includes a communication module connected to the CPU, which is used to communicate with the communication device and transmit the data results during the verification period.

5. The standard oil calibration device for online monitoring of transformer oil chromatography according to claim 1, characterized in that: The control valve and the off-line oil chromatography detection device are connected through pipelines, and the control valve and the on-line oil chromatography detection device to be tested are connected respectively.

6. The standard oil calibration device for online monitoring of transformer oil chromatography according to claim 1, characterized in that: The mobile platform is a motor vehicle.

7. A method for checking standard oil based on the device according to any one of claims 1 to 6, characterized in that: The following steps are involved: A standard oil sample of the required concentration is prepared in advance and stored in an oil tank. The control valve of the oil tank is connected to the online oil chromatography monitoring device to be tested through a pipeline, and the control valve is connected to the offline oil chromatography monitoring device through a pipeline; Exhaust and flush the residual oil left over from the last test in the online oil chromatography monitoring device to be tested; The offline oil chromatogram monitoring device is connected to the online oil chromatogram monitoring device to be tested by communication, and the same set of standard oil samples are tested and the obtained output data are used for comparison. If the error exceeds the set value, the online oil chromatogram monitoring device is calibrated according to the chromatogram peak data in the test data of the offline oil chromatogram monitoring device; if the error does not exceed the set value, the next set of standard oil samples of the concentration is switched to continue the calibration; When the calibration of the standard oil sample of the current concentration is completed, a trigger signal is issued to switch to the next set of standard oil samples of the concentration for calibration until the calibration of the standard oil samples of all concentrations is completed.

8. The standard oil calibration method for online monitoring of transformer oil chromatogram according to claim 7, characterized in that: The standard oil sample of required concentration is obtained by mixing the standard oil with characteristic gases of different component contents.

9. The standard oil calibration method for online monitoring of transformer oil chromatogram according to claim 7, characterized in that: Before the control valve of the oil tank is connected to the online oil chromatogram monitoring device to be tested through a pipeline, the network connection of the online oil chromatogram monitoring device to be tested and the oil circuit connection with the transformer are disconnected.

10. The standard oil calibration method for transformer oil chromatogram online monitoring according to claim 7, characterized in that: After the online device verification is completed, the on-site equipment connection is restored, the pipeline is flushed with the original transformer oil and the network connection is restored.

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