A fault diagnosis system for an on-line monitoring device for dissolved gases in transformer oil

Abstract

This invention discloses a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil, relating to the field of online monitoring equipment technology. It includes a sampling unit, a detection unit, a backup oil outlet unit, a backup oil-gas separation device, a recovery oil tank, a common oil outlet pipe, and a common gas sampling pipe. The sampling unit includes first to third sampling units with identical structures, and the backup oil outlet unit includes first to third backup oil outlet units with identical structures. One end of the first sampling unit is connected to the common gas sampling pipe, and the other end is connected to the common oil outlet pipe via the first backup oil outlet unit. One end of the backup oil-gas separation device is connected to the common gas sampling pipe, and the other end is connected to the common oil outlet pipe. The backup oil-gas separation device is also connected to the recovery oil tank. Through the first to third backup oil outlet units, the backup oil-gas separation device, the recovery oil tank, the common oil outlet pipe, and the common gas sampling pipe, it prevents transformer oil mixing and can promptly locate faults in any oil-gas separation unit within the monitoring device.

Description

Technical Field

[0001] This invention relates to the field of online monitoring equipment technology, and in particular to a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil. Background Technology

[0002] Transformers are the most important main equipment in a power system, and their safe and stable operation is of great significance to ensuring the safe and stable operation of the power grid. The online dissolved gas monitoring device in transformer oil (hereinafter referred to as the monitoring device) can complete dissolved gas tests in transformer insulating oil several times a day, making it one of the most effective means of monitoring the operating status of transformers.

[0003] Due to the influence of the operating environment, monitoring devices frequently malfunction. When a monitoring device fails, the dissolved gas in the transformer oil loses its online monitoring capability, making it impossible to detect internal discharge faults in the transformer in a timely manner. Therefore, online oil chromatography monitoring devices should be given equal importance to relay protection. Equipping the protection system with one main and one backup monitoring device would significantly increase costs.

[0004] The 500kV substation in this power grid area contains at least six transformers, so the explanation will take the monitoring of dissolved gases in the oil of the six transformers as an example.

[0005] Currently, online monitoring devices are deployed in a way that one device measures the dissolved gases in the oil of only one main transformer. This results in a significant waste of resources. The reason is that when one monitoring device measures the dissolved gases in the oil of multiple transformers, the following technical problems arise:

[0006] 1. When the monitoring device malfunctions, it cannot be guaranteed that the device will resume operation as quickly as a protection device.

[0007] 2. The monitoring device mainly consists of three units: an oil-gas separation unit, a gas separation unit, and a gas detection unit. Oil mixing occurs in the oil-gas separation stage. Oil samples from different transformers entering the monitoring device's oil tank cause mixing. The gas separation and gas detection stages, which do not involve insulating oil, do not pose a risk of mixing. However, the most expensive parts of the monitoring device are precisely the gas separation and gas detection units. Different transformer oils flowing through the same online monitoring device pose a risk of mixing between different transformers, i.e., the transformer oil mixing problem. For example, if the first monitoring device simultaneously monitors dissolved gases in the oils of the first and second transformers, the insulating oils from the first and second transformers may mix in the first monitoring device's oil tank. This mixed oil may then flow into both transformers, causing contamination of the insulating oil in both transformers and preventing the device from reflecting the true operating status of the transformers.

[0008] 3. When an online monitoring device measures dissolved gases in the oil of multiple transformers simultaneously, it will inevitably increase the distance between the monitoring device and the transformer, and lengthen the oil pipe connecting the transformer and the monitoring device. The longer the oil pipe, the more oil sample remains in it. Thus, the oil in the test oil for dissolved gases is the oil sample remaining in the oil pipe, which cannot reflect the dissolved gas content in the insulating oil inside the transformer at the time of sampling.

[0009] 4. The monitoring device obtains the detection data and informs the processor. The processor compares the newly obtained detection data with the previous detection data. When an abnormality is found, it cannot promptly determine which of the three units of the monitoring device—the oil-gas separation unit, the gas separation unit, and the gas detection unit—has malfunctioned, i.e., it cannot locate the faulty part.

[0010] The application, published under CN115237023A, is titled "Auxiliary Control System for Online Monitoring Device of Dissolved Gases in Transformer Oil." It achieves cross-connection of multiple transformers through a three-way pipeline, allowing one online monitoring device to test different main transformers independently by controlling solenoid valves, and enabling multiple online monitoring devices to simultaneously measure a single main transformer, thus handling data anomalies. However, this method, due to the mixed oil circuits, is prone to cross-contamination of the insulating oil and cannot intelligently locate the fault location of the fault monitoring device.

[0011] The authorized notification number is CN115406839B, and the name is "Online Monitoring Device for Dissolved Gases in Transformer Oil." Through a degassing module, main control module, host computer module, and photoacoustic spectroscopy module within an intelligent cabinet, it continuously monitors the content and growth rate of characteristic gases such as H2, CO, CO2, CH4, C2H2, C2H4, and C2H6, as well as trace amounts of water, dissolved in transformer oil at preset intervals. However, this device can only monitor the content of these gases and water in a single transformer, and when a malfunction causes abnormal data, it cannot automatically locate and eliminate the fault. Summary of the Invention

[0012] This invention provides a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil, solving the technical problems of mixed oil in transformers and the inability to locate the faulty part of the monitoring device in a timely manner.

[0013] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0014] A fault diagnosis system for an online monitoring device for dissolved gases in transformer oil includes a sampling unit and a detection unit, as well as a backup oil outlet unit, a backup oil-gas separator, a recovery oil tank, a common oil outlet pipe, and a common gas sampling pipe. The sampling unit includes first to third sampling units with identical structures, and the backup oil outlet unit includes first to third backup oil outlet units with identical structures. One end of the first sampling unit is connected to the common gas sampling pipe, and the other end of the first sampling unit is connected to the common oil outlet pipe via the first backup oil outlet unit. One end of the backup oil-gas separator is connected to the common gas sampling pipe, and the other end of the backup oil-gas separator is connected to the common oil outlet pipe. The backup oil-gas separator is also connected to the recovery oil tank. The detection unit is connected to the common gas sampling pipe, and the control terminal of the detection unit is electrically connected to the control terminal of each sampling unit, each backup oil outlet unit, and each backup oil-gas separator individually.

[0015] A further technical solution is as follows: the sampling unit includes a transformer and an oil-gas separation device on the transformer side. The oil-gas separation device includes an oil-gas separation unit, a gas sampling tube, and a gas sampling valve. The output port of the oil-gas separation unit is connected to one end of the gas sampling tube, and the other end of the gas sampling tube is connected to a common gas sampling tube. The gas sampling valve is fixedly connected to the gas sampling tube. The standby oil-gas separation device has the same structure as the oil-gas separation device on the transformer side. The oil outlet of the transformer is connected back to the oil return port of the transformer via the oil-gas separation unit on the transformer side. The standby oil outlet unit includes a standby oil outlet pipe and a standby oil outlet valve. The oil outlet of the transformer is connected to one end of the standby oil outlet pipe, and the other end of the standby oil outlet pipe is connected to a common oil outlet pipe. The standby oil outlet valve is fixedly connected to the standby oil outlet pipe. The control terminal of the detection unit is electrically connected to the control terminal of each oil-gas separation unit, each gas sampling valve, and each standby oil outlet valve.

[0016] A further technical solution includes the following steps: First detection step: The detection unit controls each sampling unit to perform oil circulation, oil sampling and oil-gas separation, and the detection unit performs gas separation and gas detection and obtains detection data.

[0017] A further technical solution includes the following steps: First fault diagnosis step: When the detection unit learns that the detection data of not all sampling units is abnormal, the detection unit controls the backup oil-gas separator and the backup oil outlet unit of the sampling unit with abnormal detection data to work, and obtains new detection data. When it is learned that the data has been updated and returned to normal, it is learned that the oil-gas separator in the sampling unit is faulty, and outputs the information that the oil-gas separator of the sampling unit is faulty and should be replaced.

[0018] A further technical solution includes a common gas pipe. The detection unit comprises a separation input pipe, a separation input valve, a gas separation unit, a separation output pipe, a separation output valve, a detection input pipe, a detection valve, a gas detection unit, and a processor. The separation input pipe, gas separation unit, separation output pipe, detection input pipe, and gas detection unit are sequentially connected and conductive. The separation input valve is fixedly connected to the separation input pipe, the separation output valve is fixedly connected to the separation output pipe, and the detection valve is fixedly connected to the detection input pipe. The gas detection unit is electrically connected to the processor. There are two detection units, namely a first detection unit and a second detection unit with identical structures. Each separation input pipe is connected and conductive to the common gas sample pipe. One end of the common gas pipe is connected to the outlet of the separation output pipe in the first detection unit, and the other end of the common gas pipe is connected to the outlet of the separation output pipe in the second detection unit. Each processor is individually electrically connected to each oil-gas separation unit, gas sample valve, spare oil outlet valve, separation input valve, separation output valve, detection valve, and gas detection unit. The two processors are electrically connected to each other.

[0019] A further technical solution includes the following steps, the second detection step:

[0020] The first detection unit controls each sampling unit to perform oil circulation, oil sampling and oil-gas separation, and performs gas separation and gas detection to obtain detection data.

[0021] Second fault diagnosis step:

[0022] When the first detection unit detects that the detection data of some sampling units is abnormal, the first detection unit controls the backup oil-gas separator and the backup oil outlet unit corresponding to the sampling unit with abnormal detection data to work and obtain new detection data. When it is known that the data has been updated and returned to normal, it is known that the oil-gas separator in the sampling unit is faulty and outputs the information that the oil-gas separator of the sampling unit is faulty and should be replaced.

[0023] A further technical solution is that, in the second fault diagnosis step, when the first detection unit learns that the corresponding detection data of all sampling units are abnormal, it starts the troubleshooting from any sampling unit.

[0024] Step 1: The processor of the second detection unit controls and only opens the gas sample valve of the current sampling unit and the separation input valve, separation output valve and detection valve of the first detection unit;

[0025] Step 2: The processor of the second detection unit controls and enables the gas separation unit and gas detection unit of the first detection unit to complete the detection and obtain the detection data. The processor of the second detection unit calculates the content of each gas in the transformer insulating oil of the current sampling unit based on the data and determines whether the detection data update of the transformer of the current sampling unit has returned to normal.

[0026] When the system returns to normal, the processor of the second detection unit outputs a message indicating that the processor of the first detection unit is faulty and needs to be replaced, and takes over all the work of the processor of the first detection unit.

[0027] If the condition does not return to normal, proceed to step three.

[0028] Step 3: The processor of the first detection unit controls and makes only the gas sample valve of the current sampling unit, the separation input valve and separation output valve of the first detection unit, and the detection valve of the second detection unit open;

[0029] Step 4: The processor of the first detection unit controls and enables the gas separation unit of the first detection unit and the gas detection unit of the second detection unit to work, complete the detection and obtain the detection data. The processor of the first detection unit calculates and obtains the content of each gas in the transformer insulating oil of the current sampling unit based on the data, and determines whether the detection data update of the transformer of the current sampling unit has returned to normal.

[0030] When the system returns to normal, the processor of the first detection unit outputs a message indicating that the gas detection unit of the first detection unit is faulty and needs to be replaced, and the gas detection unit of the second detection unit takes over all the work of the gas detection unit of the first detection unit.

[0031] If the condition does not return to normal, proceed to step five.

[0032] Step 5: The processor of the first detection unit controls and makes only the gas sample valve of the current sampling unit, the separation input valve and separation output valve of the second detection unit, and the detection valve of the first detection unit open;

[0033] Step 6: The processor of the first detection unit controls and enables the gas separation unit of the second detection unit and the gas detection unit of the first detection unit to work, complete the detection and obtain the detection data. The processor of the first detection unit calculates the content of each gas in the transformer insulating oil of the current sampling unit based on the data and determines whether the detection data update of the transformer of the current sampling unit has returned to normal.

[0034] When the system returns to normal, the processor of the first detection unit outputs a message indicating that the gas separation unit of the first detection unit is faulty and needs to be replaced. The gas separation unit of the second detection unit then takes over all the work of the gas separation unit of the first detection unit.

[0035] If the problem does not resolve itself, the processor of the first detection unit outputs information about the inter-unit pipeline and line faults.

[0036] A further technical solution is as follows: The first detection unit includes a first separation input pipe, a first separation input valve, a first gas separation unit, a first separation output pipe, a first separation output valve, a first detection input pipe, a first detection valve, a first gas detection unit, and a first processor. The first separation input pipe, the first gas separation unit, the first separation output pipe, the first detection input pipe, and the first gas detection unit are sequentially connected and conductive. The first separation input pipe is connected and conductive to a common gas sample pipe. The first separation input valve is fixedly connected to the first separation input pipe, the first separation output valve is fixedly connected to the first separation output pipe, and the first detection valve is fixedly connected to the first detection input pipe. The first gas detection unit is electrically connected to the first processor. The second detection unit includes a second separation input pipe, a second separation input valve, a second gas separation unit, a second separation output pipe, a second separation output valve, a second detection input pipe, a second detection valve, a second gas detection unit, and a second processor. One end of the common gas pipe is connected to the junction of the first separation output pipe and the first detection input pipe, and the other end of the common gas pipe is connected to the junction of the second separation output pipe and the second detection input pipe. The first gas detection unit is electrically connected to the second processor, and the second gas detection unit is electrically connected to the first processor.

[0037] A further technical solution is as follows: the first sampling unit includes a first transformer, a first oil-gas separation unit, a first gas sampling tube, and a first gas sampling valve; the first backup oil outlet unit includes a first backup oil outlet pipe and a first backup oil outlet valve; the oil outlet of the first transformer is connected back to the oil return port of the first transformer via the first oil-gas separation unit; the output port of the first oil-gas separation unit is connected to one end of the first gas sampling tube, and the other end of the first gas sampling tube is connected to a common gas sampling tube; the first gas sampling valve is fixedly connected to the first gas sampling tube; the oil outlet of the first transformer is connected to one end of the first backup oil outlet pipe, and the other end of the first backup oil outlet pipe is connected to a common oil outlet pipe; the first backup oil outlet valve is fixedly connected to the first backup oil outlet pipe; the first oil-gas separation unit, the first gas sampling tube, and the first gas sampling valve form a first oil-gas separation device.

[0038] A further technical solution is that the sampling unit further includes a fourth to a sixth sampling unit, the first to sixth sampling units have the same structure, and the backup oil outlet unit further includes a third to a sixth backup oil outlet unit, the first to sixth backup oil outlet units have the same structure.

[0039] The beneficial effects of adopting the above technical solution are as follows:

[0040] First, a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil includes a sampling unit and a detection unit, as well as a backup oil outlet unit, a backup oil-gas separator, a recovery oil tank, a common oil outlet pipe, and a common gas sampling pipe. The sampling unit includes first to third sampling units with identical structures, and the backup oil outlet unit includes first to third backup oil outlet units with identical structures. One end of the first sampling unit is connected to the common gas sampling pipe, and the other end of the first sampling unit is connected to the common oil outlet pipe via the first backup oil outlet unit. One end of the backup oil-gas separator is connected to the common gas sampling pipe, and the other end of the backup oil-gas separator is connected to the common oil outlet pipe and the recovery oil tank. The detection unit is connected to the common gas sampling pipe, and the control terminal of the detection unit is electrically connected individually to the control terminals of each sampling unit, each backup oil outlet unit, and each backup oil-gas separator. This technical solution, through the first to third backup oil outlet units, the backup oil-gas separator, the recovery oil tank, the common oil outlet pipe, and the common gas sampling pipe, avoids transformer oil mixing and can promptly locate faults in any oil-gas separator unit within the monitoring device.

[0041] Second, it also includes a common gas pipe. The detection unit includes a separation input pipe, a separation input valve, a gas separation unit, a separation output pipe, a separation output valve, a detection input pipe, a detection valve, a gas detection unit, and a processor. The separation input pipe, gas separation unit, separation output pipe, detection input pipe, and gas detection unit are connected and conductive in sequence. The separation input valve is fixedly connected to the separation input pipe, the separation output valve is fixedly connected to the separation output pipe, and the detection valve is fixedly connected to the detection input pipe. The gas detection unit is electrically connected to the processor. There are two detection units, namely a first detection unit and a second detection unit with the same structure. Each separation input pipe is connected and conductive to the common gas sample pipe. One end of the common gas pipe is connected to the outlet of the separation output pipe in the first detection unit, and the other end of the common gas pipe is connected to the outlet of the separation output pipe in the second detection unit. Each processor is electrically connected to each oil-gas separation unit, gas sample valve, spare oil outlet valve, separation input valve, separation output valve, detection valve, and gas detection unit. The two processors are electrically connected to each other. This technical solution, through the combination of two sets of detection units, three sets of sampling units, three sets of backup oil outlet units and one set of backup oil-gas separation device, can promptly locate any fault in any oil-gas separation unit, any gas separation unit, any gas detection unit and any processor in the monitoring device.

[0042] See the detailed implementation section for further description. Attached Figure Description

[0043] Figure 1 This is a distribution diagram of Embodiment 1 of the present invention;

[0044] Figure 2 This is a principle block diagram of Embodiment 1 of the present invention;

[0045] Figure 3 This is a flowchart for fault diagnosis when some transformer data is interrupted;

[0046] Figure 4 This is a flowchart for fault diagnosis when all transformer data is interrupted;

[0047] Figure 5 This is a structural diagram of an existing online oil chromatography monitoring device.

[0048] Among them: 1 First valve, 2 Second valve, 3 Third valve, 4 Fourth valve, 5 Fifth valve, 6 Sixth valve, 7 Seventh valve, 13 Thirteenth valve, 14 Fourteenth valve, 24 Fourth connecting pipe, 25 Fifth connecting pipe, 26 Sixth connecting pipe, 27 Seventh connecting pipe, 28 Eighth connecting pipe, 29 Ninth connecting pipe, 30 Tenth connecting pipe, 31 Quantitative tube, 33 Carrier gas cylinder, 35 Vacuum pump, 36 Gas pump, 37 Oil pump, 38 Lower liquid level sensor, 39 Upper liquid level sensor, 40 Pressure gauge, 41 Oil tank, 42 ​​Transformer, 43 Gas chromatography column, 44 Detector, 45 Communication unit, 46 Processor, 50 Existing oil-gas separation unit, 52 Gas separation unit, 53 Gas detection unit. Detailed Implementation

[0049] The existing online oil chromatography monitoring devices are described below.

[0050] like Figure 5 As shown, the online monitoring device is mainly divided into three major units: oil-gas separation, gas separation, and gas detection.

[0051] The online oil chromatography monitoring device includes an existing oil-gas separation unit 50, a gas separation unit 52, a gas detection unit 53, and a processor 46. The existing oil-gas separation unit 50 is used for connection to the transformer 42. The processor 46 is connected to the gas detection unit 53 and the existing oil-gas separation unit 50. The transformer 42 is the device to be tested.

[0052] The first valve 1, the second valve 2, the third valve 3, the fourth valve 4, the fifth valve 5, the sixth valve 6, the seventh valve 7, the fourth connecting pipe 24, the fifth connecting pipe 25, the sixth connecting pipe 26, the seventh connecting pipe 27, the eighth connecting pipe 28, the ninth connecting pipe 29, the tenth connecting pipe 30, the metering pipe 31, the carrier gas cylinder 33, the vacuum pump 35, the air pump 36, the oil pump 37, the lower liquid level sensor 38, the upper liquid level sensor 39, the pressure gauge 40, and the oil tank 41 form the existing oil-gas separation unit 50.

[0053] The gas detection unit 53 includes a detector 44, a communication unit 45, and a thirteenth valve 13. The detector 44 is electrically connected to the communication unit 45, and the detector 44 is connected to the outside world through the thirteenth valve 13.

[0054] The principle of the online oil chromatography monitoring device is as follows.

[0055] The existing online oil chromatography monitoring device has the following testing workflow:

[0056] Oil circulation → Oil sampling → Oil-gas separation → Gas separation → Gas detection → Oil discharge after sampling → Data processing.

[0057] 1) Oil circulation, i.e. cleaning the oil tank.

[0058] like Figure 5 As shown, processor 46 controls and closes the oil inlet valve (first valve 1) and the oil outlet valve (second valve 2) of transformer 42, and opens the third valve 3 and the fourth valve 4. Processor 46 controls vacuum pump 35 to start, drawing a vacuum into oil tank 41 until the pressure gauge 40 detects a pressure of 5 kPa. Pressure gauge 40 informs processor 46, which then controls the opening of second valve 2. Under the pressure of the oil in transformer 42 and the negative pressure in oil tank 41, oil from transformer 42 enters oil tank 41. Oil flows to the upper liquid level activation point (upper liquid level sensor 39), which informs processor 46. Processor 46 then controls the closing of second valve 2, ending the oil flow.

[0059] The processor 46 controls the opening of the third valve 3 and the fourth valve 4, briefly venting the system, and then closes the third valve 3 and the fourth valve 4; it opens the first valve 1 and starts the oil pump 37 to drain the oil; the oil is drained to the lower liquid level action point, i.e., the lower liquid level sensor 38, then the oil pump 37 is turned off, the first valve 1 is closed, and the oil draining ends. Each oil cycle requires approximately 250 mL of insulating oil to be circulated.

[0060] 2) Oil sampling.

[0061] The processor 46 controls the closure of the first valve 1 and the second valve 2, and opens the third valve 3 and the fourth valve 4. It also controls the vacuum pump 35 to start, drawing a vacuum into the oil tank 41 until the pressure gauge 40 indicates a pressure of 5 kPa. The pressure gauge 40 informs the processor 46, which then controls the opening of the second valve 2. Under the combined pressure of the transformer 42's oil and the negative pressure within the oil tank 41, oil from the transformer 42 enters the tank. Oil flows until it reaches the upper liquid level sensor 39, which then informs the processor 46. The processor 46 then controls the closure of the second valve 2, stopping the oil flow. Approximately 250 mL of insulating oil is drawn from the transformer 42 in each test.

[0062] 3) Oil-gas separation.

[0063] The processor 46 controls the vacuum pump 35 to keep working. When the pressure gauge 40 detects that the gas pressure is maintained at 5 kPa, it informs the processor 46. The processor 46 controls the vacuum pump 35 to be turned off and the air pump 36 to be turned on to blow air and stir. Combined with the vacuum negative pressure of the oil tank 41 itself, vacuum degassing is performed. The oil-gas separation ends after 30 minutes.

[0064] The gas pressure is P1. Since the volume of oil tank 41 is 500mL, 250mL is insulating oil and the gas part has a volume of 250mL.

[0065] The processor 46 controls the opening of the third valve 3, the fourth valve 4, and the vacuum pump 35 to transfer the sample gas, which is temporarily stored in a 5mL quantitative tube 31. The pressure in the quantitative tube is atmospheric pressure. According to PV=C, where P is pressure, V is volume, and C is a constant, the volume of gas in the 5mL quantitative tube under atmospheric pressure converted to the volume under pressure P1 is 5mL*P0 / P1, where P0 is atmospheric pressure and C is a constant. The proportion of the total volume of 250mL under pressure P1 is (5mL*P0 / P1) / 250mL.

[0066] 4) Gas separation.

[0067] The processor 46 controls the closure of the third valve 3, the fourth valve 4 and the fourteenth valve 14, and opens the seventh valve 7, the sixth valve 6 and the fifth valve 5, introducing the carrier gas in the carrier gas bottle 33 into the metering tube 31. The metering tube is used to store a metered amount of gas, which is 5 mL in this case. The carrier gas pushes 5 mL of sample gas to the subsequent gas chromatography column 43 for gas separation.

[0068] 5) Gas detection.

[0069] After gas separation by the gas separation unit 52, which includes a gas chromatography column 43 and corresponding connected pipelines, the characteristic gases of each component enter the detector 44 in sequence and are detected one by one; gas separation and gas detection are performed simultaneously.

[0070] The entire system operates at a constant temperature. The total volume of each component is calculated. Taking H2 as an example, detector 44 detects 5 mL of H2 in a quantitative tube, and the total volume of H2 is y μL. At constant temperature, the product of pressure and volume for a given mass of gas is constant. Therefore, the volume of 5 mL of gas in the quantitative tube at pressure P0 converted to pressure P1 is V1. Then, V1*P1 = 5 mL*P0 = L, where L is a constant. Therefore, V1 = 5 mL*P0 / P1. The proportion of this volume to the volume of 250 mL of gas at pressure P1 is k = V1 / 250 mL = (5 mL*P0 / P1) / 250 mL. The total volume of H2 in 250mL of insulating oil is yμL / k. Since P1 is typically around 10kPa, in a certain test assuming P1 = 10kPa, taking H2 as an example, the detector detected 3.2μL of H2 in 5mL of gas in the metering tube. Therefore, the total H2 content in 250mL of insulating oil is 3.2μL / k = 3.2μL / ((5mL*P0 / P1) / 250mL)) = 3.2μL / ((5mL*101kPa) / (10kPa*250mL)) = 15.84μL. At this point, the H2 content in the oil is 15.84μL / 250mL = 63.36μL / L. That is, when the detector detects a total H2 volume of 3.2 μL in a 5 mL quantitative tube, the test result is 63.36 μL / L. By the same ratio, when the detector detects a total H2 volume of a μL in a 5 mL quantitative tube, the test result is (a / 3.2)*63.63 μL / L. The same method applies to other gas analysis methods, which can provide a basis for the selection of standard gas concentration.

[0071] For example, when detector 44 detects a total H2 volume of 6 μL in a 5 mL metering tube, the test result is (6 / 3.2)*63.63 μL / L = 119.3 μL / L.

[0072] 6) Drain the oil after sampling is completed.

[0073] The processor 46 controls the opening of the third valve 3 and the fourth valve 4, briefly ventilating, and then closes the third valve 3 and the fourth valve 4; it opens the first valve 1 and starts the oil pump 37 to drain oil; the oil is drained to the lower liquid level action point, the oil pump 37 is turned off, the first valve 1 is closed, and the oil draining ends.

[0074] 7) Data processing.

[0075] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0076] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0077] Example 1:

[0078] like Figure 1 and Figure 2 As shown, this invention discloses a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil, comprising a sampling unit, a backup oil outlet unit, a backup oil-gas separation device, a recovery oil tank, a common oil outlet pipe, a common gas sampling pipe, a detection unit, and a common gas pipe. The sampling unit includes a transformer, an oil-gas separation unit, a gas sampling pipe, and a gas sampling valve. The backup oil outlet unit includes a backup oil outlet pipe and a backup oil outlet valve. The transformer's oil outlet is connected to the transformer's return oil outlet via the oil-gas separation unit. The output port of the oil-gas separation unit is connected to one end of the gas sampling pipe, and the other end of the gas sampling pipe is connected to the common gas sampling pipe. The gas sampling valve is fixedly connected to the gas sampling pipe. The transformer's oil outlet is connected to one end of the backup oil outlet pipe, and the other end of the backup oil outlet pipe is connected to the common oil outlet pipe. The backup oil outlet valve is fixedly connected to the backup oil outlet pipe. The oil-gas separation unit, the gas sampling pipe, and the gas sampling valve form an oil-gas separation device.

[0079] The monitoring device mainly consists of three units: an oil-gas separation unit, a gas separation unit, and a gas detection unit. Therefore, the design incorporates one gas separation and gas detection unit, along with six oil-gas separation units, to monitor dissolved gases in the oil of six transformers. Simultaneously, a backup gas separation unit, a backup gas detection unit, and a backup oil-gas separation unit are provided to replace any faulty modules, ensuring the monitoring device remains operational.

[0080] like Figure 1 As shown, there are six sampling units, which are the first to sixth sampling units with identical structures. There are also six standby oil outlet units, which are the first to sixth standby oil outlet units with identical structures.

[0081] The first sampling unit includes a first transformer, a first oil-gas separation unit, a first gas sampling tube, and a first gas sampling valve. The first backup oil outlet unit includes a first backup oil outlet pipe and a first backup oil outlet valve. The oil outlet of the first transformer is connected back to the oil return port of the first transformer via the first oil-gas separation unit. The output port of the first oil-gas separation unit is connected to one end of the first gas sampling tube, and the other end of the first gas sampling tube is connected to the common gas sampling tube. The first gas sampling valve is fixedly connected to the first gas sampling tube. The oil outlet of the first transformer is connected to one end of the first backup oil outlet pipe, and the other end of the first backup oil outlet pipe is connected to the common oil outlet pipe. The first backup oil outlet valve is fixedly connected to the first backup oil outlet pipe. The first oil-gas separation unit, the first gas sampling tube, and the first gas sampling valve form the first oil-gas separation device.

[0082] The second sampling unit includes a second transformer, a second oil-gas separation unit, a second gas sampling tube, and a second gas sampling valve. The second backup oil outlet unit includes a second backup oil outlet pipe and a second backup oil outlet valve. The oil outlet of the second transformer is connected back to the oil return port of the second transformer via the second oil-gas separation unit. The output port of the second oil-gas separation unit is connected to one end of the second gas sampling tube, and the other end of the second gas sampling tube is connected to the common gas sampling tube. The second gas sampling valve is fixedly connected to the second gas sampling tube. The oil outlet of the second transformer is connected to one end of the second backup oil outlet pipe, and the other end of the second backup oil outlet pipe is connected to the common oil outlet pipe. The second backup oil outlet valve is fixedly connected to the second backup oil outlet pipe. The second oil-gas separation unit, the second gas sampling tube, and the second gas sampling valve form the second oil-gas separation device.

[0083] The third sampling unit includes a third transformer, a third oil-gas separation unit, a third gas sampling tube, and a third gas sampling valve. The third backup oil outlet unit includes a third backup oil outlet pipe and a third backup oil outlet valve. The oil outlet of the third transformer is connected back to the oil return port of the third transformer via the third oil-gas separation unit. The output port of the third oil-gas separation unit is connected to one end of the third gas sampling tube, and the other end of the third gas sampling tube is connected to the common gas sampling tube. The third gas sampling valve is fixedly connected to the third gas sampling tube. The oil outlet of the third transformer is connected to one end of the third backup oil outlet pipe, and the other end of the third backup oil outlet pipe is connected to the common oil outlet pipe. The third backup oil outlet valve is fixedly connected to the third backup oil outlet pipe. The third oil-gas separation unit, the third gas sampling tube, and the third gas sampling valve form the third oil-gas separation device.

[0084] The fourth sampling unit includes a fourth transformer, a fourth oil-gas separation unit, a fourth gas sampling tube, and a fourth gas sampling valve. The fourth backup oil outlet unit includes a fourth backup oil outlet pipe and a fourth backup oil outlet valve. The oil outlet of the fourth transformer is connected back to the oil return port of the fourth transformer via the fourth oil-gas separation unit. The output port of the fourth oil-gas separation unit is connected to one end of the fourth gas sampling tube, and the other end of the fourth gas sampling tube is connected to the common gas sampling tube. The fourth gas sampling valve is fixedly connected to the fourth gas sampling tube. The oil outlet of the fourth transformer is connected to one end of the fourth backup oil outlet pipe, and the other end of the fourth backup oil outlet pipe is connected to the common oil outlet pipe. The fourth backup oil outlet valve is fixedly connected to the fourth backup oil outlet pipe. The fourth oil-gas separation unit, the fourth gas sampling tube, and the fourth gas sampling valve form the fourth oil-gas separation device.

[0085] The fifth sampling unit includes a fifth transformer, a fifth oil-gas separation unit, a fifth gas sampling tube, and a fifth gas sampling valve. The fifth backup oil outlet unit includes a fifth backup oil outlet pipe and a fifth backup oil outlet valve. The oil outlet of the fifth transformer is connected back to the oil return port of the fifth transformer via the fifth oil-gas separation unit. The output port of the fifth oil-gas separation unit is connected to one end of the fifth gas sampling tube, and the other end of the fifth gas sampling tube is connected to the common gas sampling tube. The fifth gas sampling valve is fixedly connected to the fifth gas sampling tube. The oil outlet of the fifth transformer is connected to one end of the fifth backup oil outlet pipe, and the other end of the fifth backup oil outlet pipe is connected to the common oil outlet pipe. The fifth backup oil outlet valve is fixedly connected to the fifth backup oil outlet pipe. The fifth oil-gas separation unit, the fifth gas sampling tube, and the fifth gas sampling valve form the fifth oil-gas separation device.

[0086] The sixth sampling unit includes a sixth transformer, a sixth oil-gas separation unit, a sixth gas sampling tube, and a sixth gas sampling valve. The sixth backup oil outlet unit includes a sixth backup oil outlet pipe and a sixth backup oil outlet valve. The oil outlet of the sixth transformer is connected back to the oil return port of the sixth transformer via the sixth oil-gas separation unit. The output port of the sixth oil-gas separation unit is connected to one end of the sixth gas sampling tube, and the other end of the sixth gas sampling tube is connected to the common gas sampling tube. The sixth gas sampling valve is fixedly connected to the sixth gas sampling tube. The oil outlet of the sixth transformer is connected to one end of the sixth backup oil outlet pipe, and the other end of the sixth backup oil outlet pipe is connected to the common oil outlet pipe. The sixth backup oil outlet valve is fixedly connected to the sixth backup oil outlet pipe. The sixth oil-gas separation unit, the sixth gas sampling tube, and the sixth gas sampling valve form the sixth oil-gas separation device.

[0087] The backup oil-gas separation device is the seventh oil-gas separation device. The first to seventh oil-gas separation devices have the same structure. The seventh oil-gas separation device includes a seventh oil-gas separation unit, a seventh gas sample tube, and a seventh gas sample valve. The output port of the seventh oil-gas separation unit is connected to one end of the seventh gas sample tube, and the other end of the seventh gas sample tube is connected to the common gas sample tube. The seventh gas sample valve is fixedly connected to the seventh gas sample tube.

[0088] The common oil outlet pipe is connected to the input port of the seventh oil-gas separation unit, and the output port of the seventh oil-gas separation unit is connected to the recovery oil tank.

[0089] The detection unit includes a separation input pipe, a separation input valve, a gas separation unit, a separation output pipe, a separation output valve, a detection input pipe, a detection valve, a gas detection unit, and a processor. The separation input pipe, gas separation unit, separation output pipe, detection input pipe, and gas detection unit are connected in sequence. The separation input pipe is connected to a common gas sample pipe. The separation input valve is fixedly connected to the separation input pipe, the separation output valve is fixedly connected to the separation output pipe, the detection valve is fixedly connected to the detection input pipe, and the gas detection unit is electrically connected to the processor.

[0090] There are two detection units, namely a first detection unit and a second detection unit with identical structures.

[0091] The first detection unit includes a first separation input pipe, a first separation input valve, a first gas separation unit, a first separation output pipe, a first separation output valve, a first detection input pipe, a first detection valve, a first gas detection unit, and a first processor. The first separation input pipe, the first gas separation unit, the first separation output pipe, the first detection input pipe, and the first gas detection unit are sequentially connected and conductive. The first separation input pipe is connected and conductive to a common gas sample pipe. The first separation input valve is fixedly connected to the first separation input pipe. The first separation output valve is fixedly connected to the first separation output pipe. The first detection valve is fixedly connected to the first detection input pipe. The first gas detection unit is electrically connected to the first processor.

[0092] The second detection unit includes a second separation input pipe, a second separation input valve, a second gas separation unit, a second separation output pipe, a second separation output valve, a second detection input pipe, a second detection valve, a second gas detection unit, and a second processor. The second separation input pipe, the second gas separation unit, the second separation output pipe, the second detection input pipe, and the second gas detection unit are sequentially connected and conductive. The second separation input pipe is connected and conductive to a common gas sample pipe. The second separation input valve is fixedly connected to the second separation input pipe. The second separation output valve is fixedly connected to the second separation output pipe. The second detection valve is fixedly connected to the second detection input pipe. The second gas detection unit is electrically connected to the second processor.

[0093] One end of the common gas tube is connected to the junction of the first separation output tube and the first detection input tube, and the other end of the common gas tube is connected to the junction of the second separation output tube and the second detection input tube. The first gas detection unit is electrically connected to the second processor, and the second gas detection unit is electrically connected to the first processor.

[0094] like Figure 2As shown, the first processor is electrically connected to the control terminal of the first backup oil outlet valve, the control terminal of the second backup oil outlet valve, the control terminal of the third backup oil outlet valve, the control terminal of the fourth backup oil outlet valve, the control terminal of the fifth backup oil outlet valve, the control terminal of the sixth backup oil outlet valve, the control terminal of the first oil-gas separation unit, the control terminal of the second oil-gas separation unit, the control terminal of the third oil-gas separation unit, the control terminal of the fourth oil-gas separation unit, the control terminal of the fifth oil-gas separation unit, the control terminal of the sixth oil-gas separation unit, and the control terminal of the seventh oil-gas separation unit. The device is electrically connected to the control terminal of the first gas sample valve; the first processor is electrically connected to the control terminal of the second gas sample valve; the first processor is electrically connected to the control terminal of the third gas sample valve; the first processor is electrically connected to the control terminal of the fourth gas sample valve; the first processor is electrically connected to the control terminal of the fifth gas sample valve; the first processor is electrically connected to the control terminal of the sixth gas sample valve; the first processor is electrically connected to the control terminal of the seventh gas sample valve; the first processor is electrically connected to the control terminal of the first separation input valve; the first processor is electrically connected to the control terminal of the second separation input valve; the first processor is electrically connected to the control terminal of the first separation output valve; the first processor is electrically connected to the control terminal of the second separation output valve; the first processor is electrically connected to the control terminal of the first detection valve; the first processor is electrically connected to the control terminal of the second detection valve; the first processor is electrically connected to the first gas detection unit; and the first processor is electrically connected to the second gas detection unit.

[0095] The second processor is electrically connected to the control terminal of the first backup oil outlet valve, the second backup oil outlet valve, the third backup oil outlet valve, the fourth backup oil outlet valve, the fifth backup oil outlet valve, the sixth backup oil outlet valve, the first oil-gas separation unit, the second oil-gas separation unit, the third oil-gas separation unit, the fourth oil-gas separation unit, the fifth oil-gas separation unit, the sixth oil-gas separation unit, and the seventh oil-gas separation unit. The second processor is electrically connected to the control terminal of the first gas sample valve, the control terminal of the second gas sample valve, the control terminal of the third gas sample valve, the control terminal of the fourth gas sample valve, the control terminal of the fifth gas sample valve, the control terminal of the sixth gas sample valve, the control terminal of the seventh gas sample valve, the control terminal of the first separation input valve, the control terminal of the second separation input valve, the control terminal of the first separation output valve, the control terminal of the second separation output valve, the control terminal of the first detection valve, the control terminal of the second detection valve, the control terminal of the first gas detection unit, and the control terminal of the second gas detection unit.

[0096] The first processor is electrically connected to and communicates with the second processor.

[0097] All valves are electrically controlled valves. The processor, oil-gas separation unit, gas separation unit, gas detection unit, valve itself, and corresponding communication connection technology are existing technologies and will not be described in detail here.

[0098] Description of hardware devices in the system:

[0099] The processor can control the first oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of the first transformer.

[0100] The processor can control the second oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of the second transformer.

[0101] The processor can control the third oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of the third transformer.

[0102] The processor can control the fourth oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of the fourth transformer.

[0103] The processor can control the fifth oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of the fifth transformer.

[0104] The processor can control the sixth oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of the sixth transformer.

[0105] The processor can control the opening or closing of each backup oil outlet valve, so that any transformer can be connected to the oil-gas separation unit of the backup oil-gas separation device through pipelines and valves. The processor can control the backup oil-gas separation device to complete the oil circulation, oil sampling and oil-gas separation process of any transformer.

[0106] The first to seventh gas sample valves are connected together through a common gas sample tube, and then split into two paths. The first path is connected to the first gas separation unit through the first separation input tube and the first separation input valve, and the second path is connected to the second gas separation unit through the second separation input tube and the second separation input valve.

[0107] Second testing step:

[0108] This is the gas detection process.

[0109] The first processor controls the first to sixth oil-gas separation devices to perform oil circulation, oil sampling, and oil-gas separation.

[0110] The first processor controls the opening of the first gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve, while closing other valves. It controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and then transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the first transformer.

[0111] The first processor controls the second gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve to open, while closing other valves. It controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and then transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the second transformer.

[0112] The first processor controls the third gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve to open, while closing other valves. It controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and then transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the third transformer.

[0113] The first processor controls the fourth gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve to open, while closing other valves. It controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and then transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the fourth transformer.

[0114] The first processor controls the fifth gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve to open, while closing other valves. It controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and then transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the fifth transformer.

[0115] The first processor controls the opening of the sixth gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve, while closing the other valves. It controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and then transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the sixth transformer.

[0116] Second fault diagnosis step:

[0117] This is the fault handling procedure for the monitoring device.

[0118] The troubleshooting process is divided into two categories.

[0119] The first type involves a single transformer monitoring device experiencing data interruption.

[0120] Since the six transformer monitoring devices share a single gas separation unit, gas detection unit, and processor, the normal data from the other transformers indicates that the shared components are functioning correctly. Therefore, the probability of a failure in the oil-gas separation unit is extremely high under these circumstances.

[0121] The second type involves data interruption for all six transformers.

[0122] Since each transformer is equipped with an oil-gas separation unit, the probability of data interruption caused by the simultaneous failure of all six oil-gas separation units is relatively small. Therefore, the probability of malfunctioning is extremely high, assuming a fault in the gas separation unit, gas detection unit, or processor.

[0123] The processing principle is to replace the first processor, first gas separation unit and first gas detection unit in the first detection unit one by one with the second processor, second gas separation unit and second gas detection unit in the backup second detection unit until the data update returns to normal, so as to determine the specific faulty unit.

[0124] 1. First type of processing flow:

[0125] Taking the data interruption of the first transformer as an example:

[0126] like Figure 3 As shown, the first processor controls the first backup oil outlet valve and the seventh gas sample valve to connect to the seventh oil-gas separation unit, replacing the first oil-gas separation unit to complete the oil-gas separation function of the first transformer.

[0127] When the first processor learns that the data update of the first transformer has returned to normal, the first processor outputs a message indicating that the first oil-gas separation unit is faulty and needs to be replaced.

[0128] 2. Second type of processing flow:

[0129] Data was lost for all six transformers:

[0130] like Figure 4 The diagram shows the fault diagnosis process when all transformer data is interrupted.

[0131] Step 1: The second processor controls the first gas sample valve, the first separation input valve, the first separation output valve, and the first detection valve to open, while the other valves are closed.

[0132] Step 2: The second processor controls the first gas separation unit and the first gas detection unit to complete the separation and detection of gases, and transmits the data to the second processor. The second processor calculates the content of each gas in the insulating oil of the first transformer and determines whether the data update of the first transformer monitoring device has returned to normal.

[0133] When the system returns to normal, the second processor outputs a message indicating that the first processor is faulty and needs to be replaced, and then takes over all the work of the first processor.

[0134] If the condition does not return to normal, proceed to step three.

[0135] Step 3: The first processor controls the first gas sample valve, the first separation input valve, the first separation output valve, and the second detection valve to open, while the other valves are closed.

[0136] Step 4: The first processor controls the first gas separation unit and the second gas detection unit to complete the separation and detection of gases, and transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the first transformer and determines whether the data update of the first transformer monitoring device has returned to normal.

[0137] When the system returns to normal, the first processor outputs a message indicating that the first gas detection unit is faulty and needs to be replaced, and the second gas detection unit takes over all the work of the first gas detection unit.

[0138] If the condition does not return to normal, proceed to step five.

[0139] Step 5: The first processor controls the first gas sample valve, the second separation input valve, the second separation output valve, and the first detection valve to open, while the other valves are closed.

[0140] Step 6: The first processor controls the second gas separation unit and the first gas detection unit to complete the separation and detection of gases, and transmits the data to the first processor. The first processor calculates the content of each gas in the insulating oil of the first transformer and determines whether the data update of the first transformer monitoring device has returned to normal.

[0141] When the system returns to normal, the first processor outputs a message indicating that the first gas separation unit is faulty and needs to be replaced, and the second gas separation unit takes over all the work of the first gas separation unit.

[0142] If the problem does not resolve itself, the first processor outputs information about inter-unit pipeline and line faults.

[0143] Comparing the improved detection process of Example 1 with the existing testing process, the existing technology has technical problems such as transformer oil mixing and inability to locate the fault location of the monitoring device in a timely manner. The technical solution of this application adds a backup oil outlet unit, a backup oil-gas separation device, a recovery oil tank, a common oil outlet pipe and a common gas sampling pipe, as well as a fault diagnosis step. The beneficial technical effects are as follows:

[0144] 1. By adding backup units to each unit, the monitoring device can be restored to operation immediately after a failure, just like a protective device. When the monitoring device fails, the system of this application can restore operation as quickly as possible, just like a protective device.

[0145] 2. By using the second processor, second gas separation unit, and second gas detection unit in the backup second detection unit, the first processor, first gas separation unit, and first gas detection unit in the first detection unit are replaced one by one until the data update returns to normal, in order to determine the specific faulty unit. This allows for timely location of any oil-gas separation unit fault in the monitoring device, and the replacement of the faulty unit with the backup unit to prevent the dissolved gas in the transformer oil from shutting down, automatically locating the faulty part, thus making troubleshooting more efficient and targeted.

[0146] 3. The materials required for detecting dissolved gases in the oil of six transformers are compared with existing technologies, as shown in Table 1. As can be seen from the table, except for the addition of one set of inexpensive oil-gas separation unit and recovery oil tank, the other units are reduced from six sets to two sets, which reduces costs and saves the number of detection units.

[0147] Table 1:

[0148] Module Updated technology Existing technology Oil-gas separation unit (group) 7 6 Gas separation unit (group) 2 6 Gas detection unit (group) 2 6 Processor (group) 2 6 waste oil drums 1 0

[0149] 4. To avoid cross-contamination of insulating oil during the testing process, all main transformers are routinely monitored by equipping each main transformer with a set of oil-gas separation units to avoid cross-contamination of insulating oil. At the same time, when an oil-gas separation unit fails, a backup seventh oil-gas separation unit is activated. This oil-gas separation unit only takes oil from the transformer and returns the oil directly to the recycling tank, thus avoiding cross-contamination.

[0150] 5. Standard oil comparison can effectively detect aging of the chromatographic column oven in the gas detection unit. Only two sets of detection units are needed for six main transformers, which is more efficient than the original six sets of standard oil comparison.

[0151] Example 2:

[0152] This invention discloses a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil, comprising a sampling unit, a backup oil outlet unit, a backup oil-gas separation device, a detection unit, a recovery oil tank, a common oil outlet pipe, and a common gas sampling pipe, as well as a first detection step and a first fault diagnosis step. The sampling unit includes first to third sampling units with identical structures, and the backup oil outlet unit includes first to third backup oil outlet units with identical structures. One end of the first sampling unit is connected to the common gas sampling pipe, and the other end of the first sampling unit is connected to the common oil outlet pipe via the first backup oil outlet unit. One end of the backup oil-gas separation device is connected to the common gas sampling pipe, and the other end of the backup oil-gas separation device is connected to the common oil outlet pipe and the backup oil-gas separation device is connected to the recovery oil tank. The detection unit is connected to the common gas sampling pipe, and the control terminal of the detection unit is electrically connected to the control terminals of each sampling unit, each backup oil outlet unit, and each backup oil-gas separation device. Similarities will not be repeated.

[0153] First testing step:

[0154] The detection unit controls each sampling unit to perform oil circulation, oil sampling, and oil-gas separation, while the detection unit performs gas separation and gas detection and obtains detection data.

[0155] First fault diagnosis step:

[0156] When the detection unit detects that the detection data of some sampling units is abnormal, the detection unit controls the backup oil-gas separator and the backup oil outlet unit of the sampling unit with abnormal detection data to work and obtain new detection data. When it is known that the data has been updated and returned to normal, it is known that the oil-gas separator in the sampling unit is faulty and outputs the information that the oil-gas separator of the sampling unit is faulty and should be replaced.

[0157] Example 2: A combination of one detection unit, three sampling units, three backup oil outlet units, and one backup oil-gas separation device can locate the fault of any oil-gas separation unit.

[0158] Example 3:

[0159] This invention discloses a fault diagnosis system for an online monitoring device for dissolved gases in transformer oil, comprising a sampling unit, a backup oil outlet unit, a backup oil-gas separation device, a detection unit, a recovery oil tank, a common oil outlet pipe and a common gas sampling pipe, as well as a second detection step and a second fault diagnosis step. The sampling unit includes first to third sampling units with identical structures, the backup oil outlet unit includes first to third backup oil outlet units with identical structures, and the detection unit includes first and second detection units with identical structures. The similarities will not be repeated.

[0160] Example 3, which combines two sets of detection units, three sets of sampling units, three sets of backup oil outlet units and one set of backup oil-gas separation device, can locate any failure of any oil-gas separation unit, any failure of any gas separation unit, any failure of any gas detection unit and any failure of any processor.

Claims

1. A fault diagnosis system for an online monitoring device for dissolved gases in transformer oil, comprising a sampling unit and a detection unit, characterized in that: It also includes a backup oil outlet unit, a backup oil-gas separator, a recovery oil tank, a common oil outlet pipe, and a common gas sampling pipe. The sampling unit includes first to third sampling units with identical structures, and the backup oil outlet unit includes first to third backup oil outlet units with identical structures. One end of the first sampling unit is connected to the common gas sampling pipe, and the other end of the first sampling unit is connected to the common oil outlet pipe via the first backup oil outlet unit. One end of the backup oil-gas separator is connected to the common gas sampling pipe, and the other end of the backup oil-gas separator is connected to the common oil outlet pipe. The backup oil-gas separator is also connected to the recovery oil tank. The detection unit is connected to the common gas sampling pipe. The sampling unit includes a transformer and an oil-gas separation device on the transformer side. The oil-gas separation device includes an oil-gas separation unit, a gas sampling tube, and a gas sampling valve. The output port of the oil-gas separation unit is connected to one end of the gas sampling tube, and the other end of the gas sampling tube is connected to a common gas sampling tube. The gas sampling valve is fixedly connected to the gas sampling tube. The standby oil-gas separation device has the same structure as the oil-gas separation device on the transformer side. The oil outlet of the transformer is connected back to the oil return port of the transformer via the oil-gas separation unit on the transformer side. The standby oil outlet unit includes a standby oil outlet pipe and a standby oil outlet valve. The oil outlet of the transformer is connected to one end of the standby oil outlet pipe, and the other end of the standby oil outlet pipe is connected to a common oil outlet pipe. The standby oil outlet valve is fixedly connected to the standby oil outlet pipe. It also includes a common gas pipe. The detection unit includes a separation input pipe, a separation input valve, a gas separation unit, a separation output pipe, a separation output valve, a detection input pipe, a detection valve, a gas detection unit, and a processor. The separation input pipe, gas separation unit, separation output pipe, detection input pipe, and gas detection unit are sequentially connected and conductive. The separation input valve is fixedly connected to the separation input pipe, the separation output valve is fixedly connected to the separation output pipe, and the detection valve is fixedly connected to the detection input pipe. The gas detection unit is electrically connected to the processor. There are two detection units, namely a first detection unit and a second detection unit with the same structure. Each separation input pipe is connected and conductive to the common gas sample pipe. One end of the common gas pipe is connected to the outlet of the separation output pipe in the first detection unit, and the other end of the common gas pipe is connected to the outlet of the separation output pipe in the second detection unit. Each processor is individually electrically connected to each oil-gas separation unit, gas sample valve, spare oil outlet valve, separation input valve, separation output valve, detection valve, and gas detection unit. The two processors are electrically connected to each other. Includes the following steps, Testing steps: The first detection unit controls each sampling unit to perform oil circulation, oil sampling and oil-gas separation, and performs gas separation and gas detection to obtain detection data. Fault diagnosis steps: When the first detection unit detects that the detection data of some sampling units is abnormal, the first detection unit controls the backup oil-gas separator and the backup oil outlet unit corresponding to the sampling unit with abnormal detection data to work and obtain new detection data. When it is known that the data has been updated and returned to normal, it is known that the oil-gas separator in the sampling unit is faulty and outputs the information that the oil-gas separator of the sampling unit is faulty and should be replaced.

2. The fault diagnosis system for an online monitoring device for dissolved gases in transformer oil according to claim 1, characterized in that: In the fault diagnosis process, when the first detection unit learns that the corresponding detection data of all sampling units are abnormal, it starts the troubleshooting from any sampling unit. Step 1: The processor of the second detection unit controls and only opens the gas sample valve of the current sampling unit and the separation input valve, separation output valve and detection valve of the first detection unit; Step 2: The processor of the second detection unit controls and enables the gas separation unit and gas detection unit of the first detection unit to complete the detection and obtain the detection data. The processor of the second detection unit calculates the content of each gas in the transformer insulating oil of the current sampling unit based on the data and determines whether the detection data update of the transformer of the current sampling unit has returned to normal. When the system returns to normal, the processor of the second detection unit outputs a message indicating that the processor of the first detection unit is faulty and needs to be replaced, and takes over all the work of the processor of the first detection unit. If it does not return to normal, proceed to step three; Step 3: The processor of the first detection unit controls and makes only the gas sample valve of the current sampling unit, the separation input valve and separation output valve of the first detection unit, and the detection valve of the second detection unit open; Step 4: The processor of the first detection unit controls and enables the gas separation unit of the first detection unit and the gas detection unit of the second detection unit to work, complete the detection and obtain the detection data. The processor of the first detection unit calculates and obtains the content of each gas in the transformer insulating oil of the current sampling unit based on the data, and determines whether the detection data update of the transformer of the current sampling unit has returned to normal. When the system returns to normal, the processor of the first detection unit outputs a message indicating that the gas detection unit of the first detection unit is faulty and needs to be replaced, and the gas detection unit of the second detection unit takes over all the work of the gas detection unit of the first detection unit. If the condition does not return to normal, proceed to step five. Step 5: The processor of the first detection unit controls and makes only the gas sample valve of the current sampling unit, the separation input valve and separation output valve of the second detection unit, and the detection valve of the first detection unit open; Step 6: The processor of the first detection unit controls and enables the gas separation unit of the second detection unit and the gas detection unit of the first detection unit to work, complete the detection and obtain the detection data. The processor of the first detection unit calculates the content of each gas in the transformer insulating oil of the current sampling unit based on the data and determines whether the detection data update of the transformer of the current sampling unit has returned to normal. When the system returns to normal, the processor of the first detection unit outputs a message indicating that the gas separation unit of the first detection unit is faulty and needs to be replaced. The gas separation unit of the second detection unit then takes over all the work of the gas separation unit of the first detection unit. If the problem does not resolve itself, the processor of the first detection unit outputs information about the inter-unit pipeline and line faults.

3. The fault diagnosis system for an online monitoring device for dissolved gases in transformer oil according to claim 1, characterized in that: The first detection unit includes a first separation input pipe, a first separation input valve, a first gas separation unit, a first separation output pipe, a first separation output valve, a first detection input pipe, a first detection valve, a first gas detection unit, and a first processor. The first separation input pipe, the first gas separation unit, the first separation output pipe, the first detection input pipe, and the first gas detection unit are sequentially connected and conductive. The first separation input pipe is connected and conductive to a common gas sample pipe. The first separation input valve is fixedly connected to the first separation input pipe, the first separation output valve is fixedly connected to the first separation output pipe, and the first detection valve is fixedly connected to the first detection input pipe. The first gas detection unit is electrically connected to the first processor. The second detection unit includes a second separation input pipe, a second separation input valve, a second gas separation unit, a second separation output pipe, a second separation output valve, a second detection input pipe, a second detection valve, a second gas detection unit, and a second processor. One end of the common gas pipe is connected to the junction of the first separation output pipe and the first detection input pipe, and the other end of the common gas pipe is connected to the junction of the second separation output pipe and the second detection input pipe. The first gas detection unit is electrically connected to the second processor, and the second gas detection unit is electrically connected to the first processor.

4. The fault diagnosis system for an online monitoring device for dissolved gases in transformer oil according to claim 1, characterized in that: The first sampling unit includes a first transformer, a first oil-gas separation unit, a first gas sampling tube, and a first gas sampling valve. The first backup oil outlet unit includes a first backup oil outlet pipe and a first backup oil outlet valve. The oil outlet of the first transformer is connected back to the oil return port of the first transformer via the first oil-gas separation unit. The output port of the first oil-gas separation unit is connected to one end of the first gas sampling tube, and the other end of the first gas sampling tube is connected to a common gas sampling tube. The first gas sampling valve is fixedly connected to the first gas sampling tube. The oil outlet of the first transformer is connected to one end of the first backup oil outlet pipe, and the other end of the first backup oil outlet pipe is connected to a common oil outlet pipe. The first backup oil outlet valve is fixedly connected to the first backup oil outlet pipe. The first oil-gas separation unit, the first gas sampling tube, and the first gas sampling valve form a first oil-gas separation device.

5. The fault diagnosis system for an online monitoring device for dissolved gases in transformer oil according to claim 1, characterized in that: The sampling unit also includes a fourth to a sixth sampling unit, and the first to sixth sampling units have the same structure. The backup oil outlet unit also includes a third to a sixth backup oil outlet unit, and the first to sixth backup oil outlet units have the same structure.

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