A device and method for checking oil leakage in oil tank of transformer on-load tap changer without power outage

Abstract

The present application discloses a device and method for detecting oil crosstalk between an on-load tap changer and an oil tank without power outage. The device comprises: an oil-gas separation device, an electrified oil filtering and degassing device and an oil distribution device. After the transformer oil of the on-load tap changer of the transformer is electrified and degassed by the designed electrified oil filtering and degassing device, characteristic gas helium is added by the designed oil distribution device, and then the transformer body oil sample is subjected to oil-gas separation in time periods by the designed oil-gas separation device. Whether the balance gas after the oil-gas separation contains characteristic gas is detected by mass spectrometry to determine whether oil crosstalk between the on-load tap changer and the transformer body oil tank occurs. The method does not require opening the oil tank of the on-load voltage regulating switch, has a simple process, saves a lot of cost, is not restricted by weather and humidity, and can be performed at any time. Thus, the technical problem that the prior art requires power outage detection, resulting in high cost and detection time affected by weather is solved.

Description

Technical Field

[0001] The present application relates to the technical field of transformers, and in particular to a device and method for detecting oil leakage in an on-load tap changer oil tank of a transformer without power outage. Background Art

[0002] The transformer on-load tap changer is an important component of the transformer. When the transformer is under load, it changes the output voltage of the transformer secondary side by gear switching and adjusting the winding tapping position to ensure the voltage quality of the power grid. The transformer on-load switch is generally installed in an independent oil tank on the transformer, which is physically isolated from the large oil tank of the transformer body. When the oil tank seal of the on-load tap changer is damaged, the physical isolation from the transformer body oil tank fails, and the oil and gas between the two tanks form a dissolution equilibrium, thus forming oil cross-talk. After oil cross-talk, the impact on the operation of the transformer is mainly: the oil of the on-load tap changer contaminates the oil of the transformer body, causing abnormal dissolved gas in the oil, affecting the correct judgment of the transformer state; the oil pillow of the transformer body and the oil pillow of the on-load tap changer are inconsistent in height. After oil cross-talk, the transformer body oil tank and the on-load tap changer oil tank are connected, which causes abnormal oil levels in the two oil pillows of the transformer and even oil leakage of the on-load tap changer in severe cases. The inspection of oil cross-talk in the oil tank of the transformer on-load tap changer is of great significance to the safe operation of the transformer.

[0003] The current inspection method mainly adopts the power-off inspection method, opens the oil tank of the transformer on-load tap changer, drains the oil in the on-load tap changer tank, and checks whether there is oil leakage after standing for a certain period of time, so as to judge the sealing of the on-load tap changer tank.

[0004] The existing power outage inspection methods have the following main disadvantages: First, it is impossible to find problems at the early stage of leakage or when the leakage point is small. Second, the need for power outages affects the reliability of power supply. Now, in order to improve the reliability of power supply, the transformer power outage time is limited. The power outage inspection requires opening the oil tank, pumping oil, standing, and injecting oil samples, which all require a long construction period. If the inspection result of such a long power outage is normal, it will be a problem that power grid companies will find difficult to accept. Third, the cost of power outage inspection is high, the process is relatively cumbersome and requires sufficient manpower and material support. Fourth, since the power outage inspection requires opening the oil tank to drain the oil, good weather and appropriate humidity are required to ensure that the oil tank of the on-load tap changer is not damp, so the power outage inspection is also affected by weather conditions. Summary of the invention

[0005] The present application provides a device and method for detecting oil leakage in the oil tank of an on-load tap changer of a transformer without power outage, which is used to solve the technical problems that the prior art requires power outage detection, resulting in high costs and the detection time is affected by the weather.

[0006] In view of this, the first aspect of the present application provides a transformer on-load tap changer oil tank oil leakage detection device without power outage, the device comprising: an oil-gas separation device, an electrified oil filter and degassing device, and an oil distribution device;

[0007] The live oil filter and degassing device is used to: after degassing the new transformer oil through the vacuum oil filter, the oil enters the transformer on-load tap changer oil tank, and repeatedly replaces and degasses the transformer oil in the transformer on-load tap changer oil tank, so that the original dissolved gas in the on-load tap changer oil tank is removed;

[0008] The oil distribution device and the transformer on-load tap changer oil tank form a circulation loop, which is used to add characteristic gas to the transformer oil in the circulation loop after the original dissolved gas in the on-load tap changer oil tank is removed, and perform a temperature increase process so that the characteristic gas is dissolved in the transformer oil, wherein the characteristic gas is helium;

[0009] The oil-gas separation device is used to: according to the preset separation time, adopt the dynamic headspace method, use high-purity nitrogen to purge the transformer oil released from the oil extraction valve at the bottom of the transformer body oil tank, separate the characteristic gas dissolved in the transformer oil, and store the characteristic gases at different separation times in different containers, so that oil cross-contamination inspection can be performed according to the amount of characteristic gas in each container.

[0010] Optionally, the electrified oil filtering and degassing device specifically comprises: a new oil tank, a first oil tank, a second oil tank and a vacuum oil filter;

[0011] The first oil tank is connected to the new oil tank through a valve and an oil pump, and is used to store the new transformer injected into the new oil tank;

[0012] The vacuum oil filter is connected to the first oil tank through a valve, and is used to vacuum filter and degas new transformer oil before inputting it into the second oil tank for storage, wherein the second oil tank is connected to the vacuum oil filter through a valve;

[0013] The second oil tank is connected to the transformer on-load tap changer oil tank through a valve and an oil pump, and is used to inject the degassed transformer oil into the transformer on-load tap changer oil tank through an oil return pipe for replacement, and the replaced transformer oil in the transformer on-load tap changer oil tank is input into the first oil tank through an oil drain pipe, so that the originally dissolved gas in the on-load tap changer oil tank is removed.

[0014] Optionally, the oil-gas separation device specifically comprises: an oil-gas separation device, a nitrogen bottle, a balance gas quantitative injector and a plurality of balance gas containers;

[0015] The oil inlet of the oil-gas separation device is connected to the oil inlet at the bottom of the transformer oil tank, and the oil outlet is connected to the oil inlet in the middle of the transformer oil tank, so as to realize the recycling of transformer oil and to respond to the separation instruction and separate the characteristic gas dissolved in the transformer oil according to the preset separation time;

[0016] The nitrogen cylinder is connected to the pipeline leading out of the oil extraction valve at the bottom of the transformer body oil tank, and is used to inject high-purity nitrogen into the transformer body insulating oil;

[0017] One end of the balancing gas quantitative injector is connected to the oil-gas separation device, and the other end is connected to each balancing gas container through a valve, so as to transport the characteristic gases separated at different separation times to different balancing gas containers for storage and then perform oil cross-contamination inspection according to the amount of characteristic gas in each container.

[0018] Optionally, the oil-gas separation device further includes: a vacuum pump;

[0019] The vacuum pump is connected to each balancing gas container through a valve, and is used to evacuate each balancing gas container by switching the valve before oil and gas separation.

[0020] Optionally, the oil distribution device is connected to the oil drain pipe through a first three-way valve, and is connected to the oil return pipe through a second three-way valve, thereby forming a circulation loop with the transformer on-load tap changer oil tank.

[0021] A second aspect of the present application provides a method for detecting oil leakage in an on-load tap changer oil tank without power outage, which is applied to the device for detecting oil leakage in an on-load tap changer oil tank of a transformer described in the first aspect. The method comprises:

[0022] S1. Considering the characteristic gas content in the transformer oil tank, the properties of the characteristic gas to be added, and the effect on the insulation performance of the transformer after addition, the characteristic gas to be added to the transformer on-load tap changer oil tank is selected;

[0023] S2. Repeatedly replace and degas the transformer oil in the transformer on-load tap changer oil tank through the live oil filter and degassing device, so that the original dissolved gas in the on-load tap changer oil tank is removed;

[0024] S3, adding the selected characteristic gas into the transformer on-load tap changer oil tank through an oil distribution device, so that the characteristic gas is dissolved in the transformer oil;

[0025] S4, separating the characteristic gas in the transformer oil in the transformer body oil tank through the oil-gas separation device according to the preset separation time;

[0026] S5. Based on the amount of characteristic gas obtained at different separation times, analyze whether oil cross-talk occurs between the transformer on-load tap changer oil tank and the transformer main body oil tank, and the severity of the oil cross-talk.

[0027] Optionally, the characteristic gas added to the transformer on-load tap changer oil tank is helium.

[0028] Optionally, step S5 specifically includes:

[0029] Obtain the amount of characteristic gas obtained at different separation times;

[0030] When the amount of each characteristic gas remains unchanged or changes within the preset threshold, it is determined that there is no oil cross-talk between the transformer main body tank and the transformer on-load tap changer tank;

[0031] When the amount of each characteristic gas shows an increasing trend, it is determined that oil leakage occurs between the transformer main tank and the transformer on-load tap changer tank;

[0032] When the amount of characteristic gas obtained at the second separation time is the same as or close to a preset value, it is determined that serious oil crosstalk occurs between the transformer body oil tank and the transformer on-load tap changer oil tank, wherein the preset value is: a theoretical value of the characteristic gas content of the insulating oil in the transformer body oil tank when oil crosstalk occurs between the transformer body oil tank and the transformer on-load tap changer oil tank and oil-gas balance is reached.

[0033] A third aspect of the present application provides a device for detecting oil leakage in an on-load tap changer tank without power outage, the device comprising a processor and a memory:

[0034] The memory is used to store program code and transmit the program code to the processor;

[0035] The processor is used to execute the steps of the method for checking oil leakage in the on-load tap changer tank without power outage as described in the first aspect according to the instructions in the program code.

[0036] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for checking oil leakage in the on-load tap changer tank without power outage described in the first aspect.

[0037] It can be seen from the above technical solutions that this application has the following advantages:

[0038] The present invention performs live oil filtering and degassing on the transformer oil of the on-load tap changer of the transformer through a designed live oil filtering and degassing device, and adds characteristic gas helium through a designed oil distribution device, and then performs oil and gas separation on the transformer body oil sample in different time periods through a designed oil and gas separation device, and uses mass spectrometry to detect whether the balance gas after oil and gas separation contains the characteristic gas to judge whether oil cross-talk occurs between the on-load tap changer and the transformer body oil tank.

[0039] Since the live oil filtration and degassing are first performed before adding the characteristic gas, the characteristic gas can be more easily dissolved in the transformer oil, and at the same time, the gas content of the transformer oil is not affected, and the insulation performance of the transformer oil is not affected, and free gas is not generated to cause a light gas alarm of the on-load tap changer gas relay. The inspection method based on the inspection device of the present application does not require power outage, and can be carried out as a preventive test work. By inspecting the transformer in normal operation in this way, it is possible to determine whether there is oil crosstalk, and to detect and deal with the oil crosstalk early. The use of non-stop power inspection reduces the power outage inspection time of the equipment and improves the reliability of power supply to the power grid. The present method does not require opening the oil tank of the on-load tap changer, and the process is simple, saving a lot of cost. It is not restricted by weather and humidity, and can be carried out at any time. The main influencing factors for the detection of characteristic gases dissolved in the transformer oil are still the degassing rate and the detector. This solves the technical problem that the existing technology requires power outage detection, resulting in high costs, and the detection time is affected by weather. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic structural diagram of an electrically charged oil filter degassing device and an oil distribution device provided in an embodiment of the present application;

[0041] Figure 2 This is a schematic structural diagram of an oil-gas separation device provided in an embodiment of the present application;

[0042] Figure 3 It is a flow chart of an embodiment of a method for checking oil leakage in the oil tank of an on-load tap changer of a transformer without power outage provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] See also Figure 1 and 2, a transformer on-load tap changer oil tank oil leakage detection device provided in the embodiment of the present application includes: an oil-gas separation device, an electrified oil filter and degassing device, and an oil distribution device;

[0045] in:

[0046] The live oil filter and degassing device is used to: after the new transformer oil is degassed by the vacuum oil filter, it enters the transformer on-load tap changer oil tank, and repeatedly replaces and degasses the transformer oil in the transformer on-load tap changer oil tank, so that the original dissolved gas in the on-load tap changer oil tank is removed;

[0047] like Figure 1 As shown, in one embodiment, the oil-gas separation device specifically includes: a new oil tank, a first oil tank, a second oil tank and a vacuum oil filter;

[0048] The first oil tank is connected to the new oil tank through valves (valve 2, valve 1) and an oil pump (oil pump 1), and is used to store the new transformer injected into the new oil tank; the vacuum oil filter is connected to the first oil tank through a valve (valve 3), and is used to vacuum filter and degas the new transformer oil and then input it into the second oil tank for storage, wherein the second oil tank is connected to the vacuum oil filter through a valve (valve 4); the second oil tank is connected to the transformer on-load tap changer oil tank through a valve (valve 5) and an oil pump (oil pump 2), and is used to inject the degassed transformer oil into the transformer on-load tap changer oil tank through an oil return pipe for replacement, and the replaced transformer oil in the transformer on-load tap changer oil tank is input into the first oil tank through an oil drain pipe, so that the original dissolved gas in the on-load tap changer oil tank is removed.

[0049] It should be noted that the operation process is:

[0050] Operation process 1: Open valves 1 and 2, start oil pump 1 to inject new oil in the new oil barrel into oil tank 1, and close valves 1 and 2 and oil pump 1.

[0051] Operation process 2: Open valves 3 and 4, start the vacuum oil filter to vacuum filter and degas the new oil in oil tank 1 and then enter oil tank 2, close valves 3 and 4 and the vacuum oil filter.

[0052] Operation process 3: Open valve 5 and oil pump 2, adjust three-way valves 1 and 2, let the oil drain pipe of the on-load tap changer communicate with the oil tank 1, and the oil return pipe communicate with the oil pump 2, control the oil flow in the oil drain pipe and the oil return pipe to be the same and within the safe operation range of the transformer energized, until the transformer oil in the oil tank 2 completely enters the on-load tap changer oil tank. At this time, the oil tank 1 obtains the same volume of transformer oil, close the three-way valves 1 and 2, and close the oil pump 2 and valve 5.

[0053] Repeat operation steps 2 and 3 several times. Through repeated replacement of transformer oil and vacuum oil filtration and degassing, the original dissolved gas in the on-load tapchanger tank will be removed.

[0054] The oil distribution device and the transformer on-load tap changer oil tank form a circulation loop, which is used to add characteristic gas to the transformer oil in the circulation loop after the original dissolved gas in the on-load tap changer oil tank is removed, and perform temperature treatment so that the characteristic gas is dissolved in the transformer oil, wherein the characteristic gas is helium;

[0055] like Figure 1 As shown, in one embodiment, the oil distribution device is specifically connected to the oil drain pipe through a first three-way valve, and is connected to the oil return pipe through a second three-way valve, thereby forming a circulation loop with the transformer on-load tap changer oil tank.

[0056] The oil-gas separation device is used to: according to the preset separation time, adopt the dynamic headspace method, use high-purity nitrogen to purge the transformer oil in the transformer main body oil tank, separate the characteristic gas dissolved in the transformer oil, and store the characteristic gases with different separation times in different containers, so that oil cross-contamination inspection can be carried out according to the amount of characteristic gas in each container.

[0057] like Figure 2 As shown, in one embodiment, the oil-gas separation device specifically includes: an oil-gas separation device, a nitrogen bottle, a vacuum pump, a balance gas quantitative injector and 8 balance gas containers;

[0058] The vacuum pump is used to evacuate the eight balance gas containers by switching valves (opening valves 0 to 8 and closing valve 9) before oil and gas separation, and then close valves 0 to 8.

[0059] The oil inlet of the oil-gas separation device is connected to the oil extraction port (valve) at the bottom of the transformer oil tank, and the oil outlet is connected to the oil extraction port (valve) in the middle of the transformer oil tank, so as to realize the recycling of transformer oil and to respond to the separation instruction to separate the characteristic gas dissolved in the transformer oil according to the preset separation time; the nitrogen bottle is connected to the pipeline leading out of the oil extraction valve at the bottom of the transformer oil tank, so as to inject high-purity nitrogen into the insulating oil of the transformer; one end of the balance gas quantitative injector is connected to the oil-gas separation device, and the other end is connected to each balance gas container through a valve, so as to input the characteristic gas separated at different separation times into 8 different balance gas containers for storage and then perform oil cross-talk inspection according to the amount of characteristic gas in each container.

[0060] The above is a device for detecting oil leakage in the oil tank of an on-load tap changer of a transformer without power outage provided in an embodiment of the present application, and the following is a method for detecting oil leakage in the oil tank of an on-load tap changer of a transformer without power outage provided in an embodiment of the present application.

[0061] See also Figure 1 , 2 3. A method for checking oil leakage in an on-load tap changer of a transformer without power outage is provided in an embodiment of the present application, comprising:

[0062] Step 101, taking into consideration the characteristic gas content in the transformer main body oil tank, the properties of the characteristic gas to be added, and the influence on the insulation performance of the transformer after the addition, the characteristic gas to be added to the transformer on-load tap changer oil tank is selected;

[0063] It should be noted that the characteristic gas added to the oil tank of the transformer on-load tap changer must be determined first. When selecting the characteristic gas, the following principles should be followed:

[0064] First, the transformer oil in the transformer body oil tank does not contain the characteristic gas or contains a very low amount. Otherwise, it is difficult to distinguish whether the characteristic gas is originally present in the oil sample in the transformer body or is caused by oil cross-contamination by the on-load tap changer oil sample.

[0065] Secondly, this characteristic gas needs to be easily soluble in the transformer oil. In this way, the gas is dissolved in the oil sample of the on-load tap changer and enters the transformer oil sample through the oil cross-talk. The detection of the characteristic gas dissolved in the transformer oil sample indicates that oil cross-talk has occurred.

[0066] Third, the gas dissolved in the transformer oil in an appropriate amount will not have a significant impact on the performance of the transformer oil, especially the insulation performance.

[0067] The carrier gas (nitrogen, argon, helium) used for transformer oil gas chromatography analysis is easily dissolved in transformer oil. The volume fractions of nitrogen and argon in the air are 78.08% and 0.93%, respectively, while the content of helium in the air is 5.24μL / L, which is very small in volume fraction and the amount dissolved in transformer oil is also very small. Transformer oil is difficult to be completely isolated from the air during operation, so the transformer oil itself contains a certain amount of nitrogen and argon, so nitrogen and argon are excluded as characteristic gases.

[0068] Helium is also commonly used as a carrier gas in oil chromatography online monitoring devices. As long as the total amount of gas dissolved in the oil is controlled, it will not affect the insulation properties of the transformer oil. Therefore, this application selects helium as the characteristic gas.

[0069] Step 102, repeatedly replacing and degassing the transformer oil in the on-load tap changer oil tank of the transformer by means of an electrified oil filter and degassing device, so that the originally dissolved gas in the on-load tap changer oil tank is removed;

[0070] It should be noted that no capsule is installed on the oil pillow of the transformer on-load tap changer, so the gas content dissolved in the transformer oil in the oil tank of the transformer on-load tap changer is relatively high. In order to add helium that can be quickly dissolved in the oil without affecting the insulation performance of the transformer oil, and also in order to accurately determine whether oil cross-talk occurs in the oil tank of the on-load tap changer, this embodiment designs a set of live oil filter degassing device and oil distribution device as in the above-mentioned embodiment 1.

[0071] Before the oil cross-contamination inspection, the gas originally dissolved in the oil tank of the on-load tap-changer is first removed by vacuum oil filtration using a device, and helium is added to the oil tank of the on-load tap-changer through the oil distribution device; after the inspection, if it is confirmed that there is no oil cross-contamination, the helium dissolved in the oil tank of the on-load tap-changer is filtered out again through the live oil filter degassing device.

[0072] like Figure 1 As shown, all valves are in the initial closed state, and the oil tanks 1, 2 and the on-load tap-changer oil tank are of equal volume.

[0073] Operation process 1: Open valves 1 and 2, start oil pump 1 to inject new oil in the new oil barrel into oil tank 1, and close valves 1 and 2 and oil pump 1.

[0074] Operation process 2: Open valves 3 and 4, start the vacuum oil filter to vacuum filter and degas the new oil in oil tank 1 and then enter oil tank 2, close valves 3 and 4 and the vacuum oil filter.

[0075] Operation process 3: Open valve 5 and oil pump 2, adjust three-way valves 1 and 2, let the oil drain pipe of the on-load tap changer communicate with the oil tank 1, and the oil return pipe communicate with the oil pump 2, control the oil flow in the oil drain pipe and the oil return pipe to be the same and within the safe operation range of the transformer energized, until the transformer oil in the oil tank 2 completely enters the on-load tap changer oil tank. At this time, the oil tank 1 obtains the same volume of transformer oil, close the three-way valves 1 and 2, and close the oil pump 2 and valve 5.

[0076] Repeat operation steps 2 and 3 several times. Through repeated replacement of transformer oil and vacuum oil filtration and degassing, the original dissolved gas in the on-load tapchanger tank will be removed.

[0077] Step 103, adding the selected characteristic gas into the transformer on-load tap changer oil tank through the oil distribution device, so that the characteristic gas is dissolved in the transformer oil;

[0078] like Figure 1As shown, first determine the helium content in the configured transformer oil. The volume ratio of the transformer body oil tank to the on-load tap changer oil tank of different voltage levels is different, ranging from about 200:1 to 500:1. If oil cross-talk occurs, theoretically, the transformer oil of the on-load tap changer and the transformer body will eventually dissolve in oil and gas equilibrium, and the helium value of the two tanks after equilibrium is about 1 / 500 to 1 / 200 of the initial helium value in the on-load tap changer transformer oil. This method determines that the helium value of the on-load tap changer transformer oil is configured to be about 10000μL / L. Since the oil in the on-load tap changer has been vacuum filtered and degassed, the gas content in the on-load tap changer oil is mainly helium. The converted value of the gas content in the oil is 1%, which is lower than the safe operation value of the transformer oil (the gas content of 500kV transformer oil during operation is ≤3%). If oil-gas dissolution equilibrium occurs, the helium content of the transformer oil in the transformer body oil tank is 20 to 50μL, and the impact on the gas content of the transformer body oil tank is 0.002% to 0.005%, which can be ignored.

[0079] Then helium is added to the on-load tapchanger transformer oil through the oil distribution device. Figure 1 As shown, all valves are in the initial closed state. The three-way valve 1 is adjusted to connect the oil drain pipe with the oil inlet of the oil distribution device, and the three-way valve 2 is adjusted to connect the oil return pipe with the oil outlet of the oil distribution device. The transformer oil in the on-load tap changer tank enters the oil distribution device, and the oil distribution device slowly adds helium into the transformer oil. Since the transformer oil has been degassed by vacuum oil filtration, the slowly added helium is easily dissolved in the transformer oil. The oil distribution device has a heating function, which heats the transformer oil temperature to 70 degrees Celsius. The dissolution rate of helium in the transformer oil increases with the increase of temperature. By controlling the flow rate of transformer oil and the flow rate of helium, the transformer oil at the oil outlet of the oil distribution device will not produce free gas. The on-load tap changer tank and the oil distribution device form a circulation loop. After multiple cycles, all the helium (the volume is one percent of the on-load tap changer tank) is injected into the transformer oil, so that the helium contained in the transformer oil is about 1%, that is, the target value of 10000μL / L.

[0080] Step 104, separating characteristic gases from the transformer oil in the transformer body oil tank by an oil-gas separation device according to a preset separation time;

[0081] like Figure 2 As shown in the figure, if oil cross-talk occurs between the transformer tank and the on-load tap-changer tank, the two tanks will form an oil-gas balance, and helium will enter the transformer oil of the main tank from the on-load tap-changer transformer oil. The oil-gas balance speed and the amount of helium in the transformer oil of the main tank depend on the size of the leak in the on-load tap-changer tank.

[0082] To detect whether the transformer oil in the main body oil tank contains helium, it is necessary to separate the helium from the transformer oil through oil-gas separation. This embodiment designs a fully automatic device (such as the oil-gas separation device of the above-mentioned embodiment 1) that can freely set the time to separate the transformer oil in different time periods. The automatic oil-gas separation device adopts a dynamic headspace method to purge the transformer oil with high-purity nitrogen to take out the helium dissolved in the transformer oil. The oil inlet of the device is connected to the oil extraction port at the bottom of the transformer main body oil tank, and the oil outlet is connected to the oil extraction port in the middle of the transformer main body oil tank to realize the recycling of transformer oil. In order to avoid the interference of helium in the air, the device is equipped with a vacuum pumping function. Before oil-gas separation, the 8 balance gas containers are vacuumed by switching valves (opening valves 0 to 8 and closing valves 9), and valves 0 to 8 are closed after completion.

[0083] The device can be used to freely set the oil-gas separation start time, set the time when the on-load tap changer has just completed the oil distribution to t0, start the oil-gas separation device to separate the oil and gas in the transformer oil at time t0, then open valves 0 and 9, and add the balance gas to the balance gas container #0 through the quantitative injector. The device can be set to eight times from t0 to t7. The device can automatically start the oil-gas separation within these eight times and automatically store the obtained balance gas in the corresponding balance gas container. If oil cross-talk occurs, the helium in the main transformer oil will first increase and then remain stable. Except for the blank value of helium in the balance gas at time t0, the change of helium in the remaining 7 balance gas containers is also the same.

[0084] Step 105: Analyze whether oil cross-talk occurs between the transformer on-load tap changer oil tank and the transformer main body oil tank and the severity of the oil cross-talk according to the amount of characteristic gas obtained at different separation times.

[0085] This embodiment uses mass spectrometry to analyze the equilibrium gas obtained by oil and gas separation at eight times.

[0086] There is almost no helium in the balance gas at time t0. Even if there is a trace of helium, it can be used as the blank value of the test. Detect the helium content in the remaining 7 balance gases and compare it with t0. If the helium values ​​C(t1)~C(t7) in the volume of the 7 balance gases are almost the same as C(t0), there is no oil cross-talk between the transformer body oil tank and the on-load tap changer oil tank. If C(t1)~C(t7) shows a gradual increase trend compared with C(t0), it is judged that there is oil cross-talk. In the oil distribution, the helium value of the on-load tap changer transformer oil is configured to about 10000μL / L. Therefore, the helium content of the transformer oil in the oil-gas balance transformer body oil tank after oil cross-talk is calculated according to the following formula.

[0087] C = 10000 μL × V1 ÷ V2;

[0088] Among them, V1 is the transformer oil volume of the on-load tap changer, and V2 is the transformer oil volume of the main body tank.

[0089] Further compare the size of C(t1)~C(t7) with C. If C(t1) is close to C, it means that the oil-gas balance has been completed at t1, the leakage point of the on-load tap changer oil tank is large, and the oil spill is serious, which should be handled urgently. If C(t4)~C(t7) are similar in size and close to C, it means that the oil-gas balance is completed around t4, and the oil spill speed is medium. It should be handled according to the situation. If C(t7) is still less than C, it means that although the two oil tanks have oil spill, they have not yet reached oil-gas balance, the oil spill speed is slow, the leakage point is small, and the equipment can be temporarily handled.

[0090] Furthermore, an embodiment of the present application also provides a device for detecting oil leakage in an on-load tap changer tank without power outage, the device comprising a processor and a memory:

[0091] The memory is used to store program code and transmit the program code to the processor;

[0092] The processor is used to execute the on-load tap changer oil tank oil leakage detection method without power outage described in the above method embodiment according to the instructions in the program code.

[0093] Furthermore, a computer-readable storage medium is provided in an embodiment of the present application, and the computer-readable storage medium is used to store program code, and the program code is used to execute the method for checking oil leakage in the on-load tap changer tank without power outage as described in the above method embodiment.

[0094] The terms "first", "second", "third", "fourth", etc. in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0095] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0096] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0097] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0098] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0099] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0100] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A transformer on-load tap changer oil tank oil leakage detection device without power outage, characterized in that: include: Oil-gas separation device, charged oil filter and degassing device and oil distribution device; The live oil filter and degassing device is used to: after degassing the new transformer oil through the vacuum oil filter, the oil enters the transformer on-load tap changer oil tank, and repeatedly replaces and degasses the transformer oil in the transformer on-load tap changer oil tank, so that the original dissolved gas in the on-load tap changer oil tank is removed; The oil distribution device and the transformer on-load tap changer oil tank form a circulation loop, which is used to add characteristic gas to the transformer oil in the circulation loop after the original dissolved gas in the on-load tap changer oil tank is removed, and perform a temperature increase process so that the characteristic gas is dissolved in the transformer oil, wherein the characteristic gas is helium; The oil-gas separation device is used to: according to the preset separation time, adopt the dynamic headspace method, use high-purity nitrogen to purge the transformer oil released by the oil extraction valve at the bottom of the transformer body oil tank, separate the characteristic gas dissolved in the transformer oil, and store the characteristic gases at different separation times in different containers, so that the oil cross-contamination inspection can be carried out according to the amount of characteristic gas in each container; The electrified oil filtering and degassing device specifically comprises: a new oil tank, a first oil tank, a second oil tank and a vacuum oil filter; The first oil tank is connected to the new oil tank through a valve and an oil pump, and is used to store the new transformer injected into the new oil tank; The vacuum oil filter is connected to the first oil tank through a valve, and is used to vacuum filter and degas new transformer oil before inputting it into the second oil tank for storage, wherein the second oil tank is connected to the vacuum oil filter through a valve; The second oil tank is connected to the transformer on-load tap changer oil tank through a valve and an oil pump, and is used to inject the degassed transformer oil into the transformer on-load tap changer oil tank through an oil return pipe for replacement, and the replaced transformer oil in the transformer on-load tap changer oil tank is input into the first oil tank through an oil drain pipe, so that the originally dissolved gas in the on-load tap changer oil tank is removed.

2. The transformer on-load tap changer oil tank oil leakage detection device according to claim 1 is characterized in that: The oil-gas separation device specifically comprises: an oil-gas separation device, a nitrogen bottle, a balance gas quantitative injector and a plurality of balance gas containers; The oil inlet of the oil-gas separation device is connected to the oil inlet at the bottom of the transformer oil tank, and the oil outlet is connected to the oil inlet in the middle of the transformer oil tank, so as to realize the recycling of transformer oil and to respond to the separation instruction and separate the characteristic gas dissolved in the transformer oil according to the preset separation time; The nitrogen cylinder is connected to the pipeline leading out of the oil extraction valve at the bottom of the transformer body oil tank, and is used to inject high-purity nitrogen into the transformer body insulating oil; One end of the balancing gas quantitative injector is connected to the oil-gas separation device, and the other end is connected to each balancing gas container through a valve, so as to transport the characteristic gases separated at different separation times to different balancing gas containers for storage and then perform oil cross-contamination inspection according to the amount of characteristic gas in each container.

3. The transformer on-load tap changer oil tank oil leakage detection device according to claim 2 is characterized in that: The oil-gas separation device further includes: a vacuum pump; The vacuum pump is connected to each balancing gas container through a valve, and is used to evacuate each balancing gas container by switching the valve before oil and gas separation.

4. The transformer on-load tap changer oil tank oil leakage detection device according to claim 1 is characterized in that: The oil distribution device is connected to the oil drain pipe through a first three-way valve and is connected to the oil return pipe through a second three-way valve, thereby forming a circulation loop with the transformer on-load tap changer oil tank.

5. A method for checking oil leakage in the oil tank of a transformer on-load tap changer without power outage, characterized in that: The device for detecting oil leakage in the oil tank of the transformer on-load tap changer without power outage according to any one of claims 1 to 4 comprises: S1. Considering the characteristic gas content in the transformer oil tank, the properties of the characteristic gas to be added, and the effect on the insulation performance of the transformer after addition, the characteristic gas to be added to the transformer on-load tap changer oil tank is selected; S2. Repeatedly replace and degas the transformer oil in the transformer on-load tap changer oil tank through the live oil filter and degassing device, so that the original dissolved gas in the on-load tap changer oil tank is removed; S3, adding the selected characteristic gas into the transformer on-load tap changer oil tank through an oil distribution device, so that the characteristic gas is dissolved in the transformer oil; S4, separating the characteristic gas in the transformer oil in the transformer body oil tank through the oil-gas separation device according to the preset separation time; S5. Based on the amount of characteristic gas obtained at different separation times, analyze whether oil cross-talk occurs between the transformer on-load tap changer oil tank and the transformer main body oil tank, and the severity of the oil cross-talk.

6. The method for checking oil leakage in the oil tank of the on-load tap changer without power outage according to claim 5 is characterized in that: The characteristic gas added to the transformer on-load tap changer oil tank is helium.

7. The method for checking oil leakage in the oil tank of the on-load tap changer without power outage according to claim 6 is characterized in that: Step S5 specifically includes: Obtain the amount of characteristic gas obtained at different separation times; When the amount of each characteristic gas remains unchanged or changes within the preset threshold, it is determined that there is no oil cross-talk between the transformer main tank and the transformer on-load tap changer tank; When the amount of each characteristic gas shows an increasing trend, it is determined that there is oil leakage between the transformer main tank and the transformer on-load tap changer tank; When the amount of characteristic gas obtained at the second separation time is the same as or close to a preset value, it is determined that serious oil crosstalk occurs between the transformer body oil tank and the transformer on-load tap changer oil tank, wherein the preset value is: a theoretical value of the characteristic gas content of the insulating oil in the transformer body oil tank when oil crosstalk occurs between the transformer body oil tank and the transformer on-load tap changer oil tank and oil-gas balance is reached.

8. An on-load tap changer oil tank oil leakage detection device without power outage, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the method for checking oil leakage in the oil tank of the on-load tap changer without power outage according to any one of claims 5 to 7 according to the instructions in the program code.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for checking oil leakage in the oil tank of an on-load tap changer without power outage according to any one of claims 5 to 7.

Images