Transformer insulating oil gas production test device and gas production method

Abstract

The invention belongs to the field of insulating oil characteristic research, and discloses a transformer insulating oil gas production test device and gas production method.The transformer insulating oil gas production test device comprises an oil tank body, and a pressure gauge, an exhaust one-way valve, an electrode assembly and a gas collection assembly are sequentially arranged at the top of the oil tank body in the same transverse direction; a flange sight glass assembly is arranged on the outer side wall of the oil tank body, a plurality of three-way ball valves are evenly arranged on the side, away from the flange sight glass assembly, of the outer portion of the oil tank body in the same longitudinal direction, and heating assemblies are arranged between the three-way ball valves and the oil tank body. According to the invention, the total gas production amount, the dissolved gas content and the free gas content under different energy discharge faults can be quantitatively measured through the concentration of the dissolved gas in the oil, the oil volume, the gas volume in the air bag and the gas injection amount during balancing.

Description

Technical Field

[0001] The present invention relates to the field of insulating oil property research, and in particular to a transformer insulating oil gas production test device and a gas production method. Background Art

[0002] Power transformers are core components of power grid systems, making their condition assessment and fault diagnosis crucial. Dissolved Gas Analysis (DGA) is a commonly used fault analysis method for oil-immersed power equipment and is highly effective in diagnosing latent faults within transformers and their progression.

[0003] At present, existing technologies have measured the gas production of discharges at different energy levels. For local discharges with low energy levels, the amount of dissolved gas is used as the gas production. When taking oil samples, most of the time, only one sampling position is set in the oil tank, and sampling and analysis are carried out at fixed intervals. Multiple sampling points are not set in the oil tank. For spark discharges and breakdown discharges with higher energy levels, a gas collection device is used to collect free gas, and the amount of free gas is used as the gas production. Both methods only focus on the larger proportion of free gas and dissolved gas in the source of gas production, which makes it difficult to truly reflect the gas production situation under transformer discharge faults.

[0004] Therefore, how to provide a transformer insulating oil gas production test device and gas production method is a problem that needs to be solved urgently. Summary of the Invention

[0005] The embodiments of the present invention provide a transformer insulating oil gas production test device and gas production method to solve the problem that the existing technology only focuses on the larger one of the free gas and dissolved gas, and it is difficult to truly reflect the gas production situation under the transformer discharge fault.

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, the following is a brief summary. This summary is not intended to be a comprehensive review, identify key or essential elements, or delineate the scope of these embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the detailed description that follows.

[0007] According to a first aspect of an embodiment of the present invention, a transformer insulating oil gas generation test device is provided.

[0008] In one embodiment, a transformer insulating oil gas production test device includes an oil tank body, on the top of which a pressure gauge, an exhaust one-way valve, an electrode assembly and a gas collecting assembly are sequentially arranged along the same horizontal direction; the outer side wall of the oil tank body is provided with a flange sight glass assembly, and a plurality of three-way ball valves are evenly arranged along the same longitudinal direction on the side of the outside of the oil tank body away from the flange sight glass assembly, and a heating assembly is provided between the three-way ball valve and the oil tank body.

[0009] In one embodiment, the oil tank body consists of a box body and a cover plate, the cylindrical box body is arranged at the bottom end of the cover plate, and a fixing chuck is arranged between the cylindrical box body and the cover plate, and the box body and the cover plate are both made of stainless steel.

[0010] In one embodiment, the electrode assembly includes a brass fixed column 1 inserted and arranged in the middle position of the top of the box body, a rotating disk is arranged on the top of the brass fixed column 1, a ceramic insulating sleeve 1 is sleeved on the outer side of the circumference of the brass fixed column 1, and the ceramic insulating sleeve 1 is arranged on the top of the cover plate, and a needle electrode is arranged at the bottom end of the brass fixed column 1; a plate electrode matching the needle electrode is inserted and arranged at the inner bottom of the box body, the outlet end of the needle electrode is connected between the rotating disk and the ceramic insulating sleeve 1, and the outlet end of the plate electrode is connected to the outside of the brass fixed column 1 at the bottom of the ceramic insulating sleeve 1.

[0011] In one embodiment, the gas collecting assembly includes a two-way ball valve arranged on one side of the top of the cover plate, an air bag is arranged on the top of the two-way ball valve, and a gas collecting hole that cooperates with the air bag is opened on the top of the cover plate, and the gas collecting hole is a conical structure. The two-way ball valve is connected to the air bag to collect free gas. When the air bag is removed from the two-way ball valve, the air tightness of the air bag is ensured. At the same time, the top side of the cover plate is set as a gas collecting hole with a conical structure, so that the free gas can flow to the air bag more easily through the gas collecting hole.

[0012] In one embodiment, the flange sight glass assembly includes a tempered borosilicate glass arranged on the outer wall of the oil tank body, and the tempered borosilicate glass is aligned with the needle electrode and the plate electrode for observing the gas production process of the discharge fault; a flange is provided on the outer side of the tempered borosilicate glass, and a polytetrafluoroethylene gasket is provided between the flange and the oil tank body. The flange and the tempered borosilicate glass are both connected to the oil tank body by screws. The heating assembly includes a heating plate arranged on the outside of the oil tank body away from the tempered borosilicate glass side, and the outside of the heating plate is provided with thermal insulation cotton. The oil tank body is heated by the heating plate, so that when the oil temperature in the oil tank body reaches the preset temperature, the temperature is kept constant by the thermal insulation cotton.

[0013] According to a second aspect of an embodiment of the present invention, a gas production method of a transformer insulating oil gas production test device is provided.

[0014] In one embodiment, a gas production method of a transformer insulating oil gas production test device includes:

[0015] Adjust the rotating disc on the top of the tank body so that the gap between the needle electrode and the plate electrode reaches the preset position;

[0016] Pour insulating oil into the box until it is full, exhaust the gas in the air bag, open the two-way ball valve switch to connect the air bag and the box, and then connect the wires according to the discharge test circuit;

[0017] Adjust the temperature of the heater outside the box and wait for the oil temperature inside the box to stabilize before starting the electrical fault simulation.

[0018] During the electrical fault simulation, after the voltage of the two sections of the plate is raised to the fault voltage, partial discharge simulation, low-energy discharge simulation and high-energy discharge simulation are performed respectively, and the amount of free gas and dissolved gas is calculated based on the discharge simulation results.

[0019] In one embodiment, the stable oil temperature inside the tank is 60°C.

[0020] In one embodiment, before pouring insulating oil into the box, the method further includes:

[0021] The insulating oil is added into a vacuum drying oven, and the vacuum drying oven is adjusted to the preset conditions to dehydrate and degas the insulating oil.

[0022] In one embodiment, performing a partial discharge simulation includes:

[0023] Monitor the voltage between the two sections of the plate. When the voltage between the two sections of the plate rises to the fault voltage, oil samples are taken based on the preset sampling conditions to study the diffusion of dissolved gas at different locations.

[0024] The preset sampling conditions include:

[0025] The timing starts from the moment when the voltage between the two sections of the plate rises to the fault voltage. The oil sample is taken every preset time. A group of two tubes is taken from each sampling port. 40ml of oil sample is drawn through a 100ml syringe. The oil sample is continued to be drawn within 2 hours after the partial discharge simulation is completed.

[0026] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0027] 1. The test device for transformer insulating oil gas production provided by the present invention takes into account both dissolved gas and free gas, and quantitatively analyzes the gas production law of transformer oil under different discharge energies. On this basis, a temperature controllable device is added to simulate the oil temperature under normal operating conditions of the transformer. At the same time, considering the diffusion of dissolved gas in oil, the gas content in oil samples in different areas varies. Several oil sampling points are set at equal intervals at different heights from top to bottom. While obtaining the dissolved gas content, the diffusion of dissolved gas in the oil tank during the gas production process can also be further explored.

[0028] 2. The present invention is used to simulate gas production caused by transformer oil-electric faults, study the gas production rules of insulating oil cracking at different energy levels, and support free gas collection and measurement and dissolved gas collection and measurement.

[0029] 3. The inner side of the cover plate in the present invention is designed with a conical structure to construct a passage for free gas, which is convenient for collecting free gas. Combined with the two-way ball valve and the gas collecting assembly, the free gas and transformer oil are separated. At the same time, the total gas production, dissolved gas content and free gas content under different energy discharge faults can be quantitatively measured by the dissolved gas concentration in the oil, the oil volume, the gas volume in the air bag and the gas injection volume during equilibrium.

[0030] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0032] Figure 1 1 is a schematic structural diagram of a transformer insulating oil gas production test device according to an exemplary embodiment;

[0033] Figure 2 This is a flow chart showing a gas production method of a transformer insulating oil gas production test device according to an exemplary embodiment;

[0034] Figure 3 This is a schematic diagram of a discharge test circuit in a gas generation method of a transformer insulating oil gas generation test device according to an exemplary embodiment;

[0035] Figure 4 The present invention is a schematic diagram of an oil sample extraction process in a gas production method of a transformer insulating oil gas production test device according to an exemplary embodiment.

[0036] Reference numerals:

[0037] 1. Fuel tank body; 101. Tank body; 102. Cover plate; 103. Fixing chuck; 2. Pressure gauge; 3. Exhaust check valve; 4. Electrode assembly; 401. Brass fixing column 1; 402. Rotating disc; 403. Ceramic insulating sleeve 1; 404. Needle electrode; 405. Plate electrode; 406. Brass fixing column 2; 407. Ceramic insulating sleeve 2; 5. Gas collecting assembly; 501. Two-way ball valve; 502. Air bag; 503. Gas collecting hole; 6. Flange sight glass assembly; 601. Tempered borosilicate glass; 602. Flange plate; 603. Polytetrafluoroethylene gasket; 604. Screw; 7. Three-way ball valve; 8. Heating assembly; 801. Heating plate; 802. Insulation cotton; 9. Connecting pipe; 10. Syringe. DETAILED DESCRIPTION

[0038] The following description and accompanying drawings sufficiently illustrate the specific embodiments herein to enable those skilled in the art to practice them. Portions and features of some embodiments may be included in or substituted for portions and features of other embodiments. The scope of the embodiments herein includes the entire scope of the claims, including all available equivalents thereof. Herein, the terms "first," "second," and the like are used solely to distinguish one element from another and do not require or imply any actual relationship or order between these elements. In practice, the first element can also be referred to as the second element, and vice versa. Furthermore, the terms "comprise," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a structure, device, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such structure, device, or apparatus. Without further limitation, an element defined by the phrase "comprising a..." does not preclude the presence of other identical elements in the structure, device, or apparatus comprising the element. The various embodiments herein are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Similar or identical parts between the various embodiments can be referenced to each other.

[0039] The terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used herein to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are intended only to facilitate the description of this document and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In the description herein, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, they can be mechanical or electrical connections, or they can be internal connections between two elements, they can be directly connected, or they can be indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0040] As used herein, unless otherwise specified, the term "plurality" means two or more.

[0041] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0042] In this article, the term "and / or" is used to describe the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0043] It should be understood that, although the various steps in the flowchart are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps may be performed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but may be performed at different times. The execution order of these sub-steps or stages is not necessarily to be performed in sequence, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0044] Each module in the device or system of the present application can be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software so that the processor can call and execute the operations corresponding to the above modules.

[0045] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0046] Figure 1An embodiment of a transformer insulating oil gas generation test device according to the present invention is shown.

[0047] In this optional embodiment, the transformer insulating oil gas production test device includes an oil tank body 1, and a pressure gauge 2, an exhaust one-way valve 3, an electrode assembly 4 and a gas collecting assembly 5 are arranged in sequence on the top of the oil tank body 1 along the same horizontal direction; a flange sight glass assembly 6 is provided on the outer wall of the oil tank body 1, and a plurality of three-way ball valves 7 are evenly arranged on the side of the outside of the oil tank body 1 away from the flange sight glass assembly 6 along the same longitudinal direction, and a heating assembly 8 is provided between the three-way ball valve 7 and the oil tank body 1.

[0048] In this optional embodiment, the oil tank body 1 is composed of a box body 101 and a cover plate 102. The cylindrical box body 101 is arranged at the bottom end of the cover plate 102, and a fixed chuck 103 is arranged between the cylindrical box body 101 and the cover plate 102. The box body 101 and the cover plate 102 are both made of stainless steel.

[0049] In this optional embodiment, the electrode assembly 4 includes a brass fixed column 401 inserted into the middle position of the top of the box body 101, a rotating disk 402 is provided on the top of the brass fixed column 401, a ceramic insulating sleeve 403 is provided on the outer side of the circumference of the brass fixed column 401, and the ceramic insulating sleeve 403 is provided on the top of the cover plate 102, and a needle electrode 404 is provided at the bottom end of the brass fixed column 401; a plate electrode 405 that matches the needle electrode 404 is inserted into the inner bottom of the box body 101, and the outlet end of the needle electrode 404 is connected between the rotating disk 402 and the ceramic insulating sleeve 403, and the outlet end of the plate electrode 405 is connected to the outside of the brass fixed column 401 at the bottom of the ceramic insulating sleeve 403.

[0050] In this optional embodiment, the gas collecting assembly 5 includes a two-way ball valve 501 arranged on one side of the top of the cover plate 102, and an air bag 502 is arranged on the top of the two-way ball valve 501. A gas collecting hole 503 that cooperates with the air bag 502 is opened on the top of the cover plate 102, and the gas collecting hole 503 is a conical structure. The two-way ball valve 501 is connected to the air bag 502 to collect free gas. When the air bag 502 is removed from the two-way ball valve 501, the air tightness of the air bag is ensured. At the same time, the top side of the cover plate 102 is set as a conical gas collecting hole 503, so that the free gas can more easily flow to the air bag 502 through the gas collecting hole 503.

[0051] In this optional embodiment, the flange sight glass assembly 6 includes a tempered borosilicate glass 601 arranged on the outer wall of the oil tank body 1, and the tempered borosilicate glass 601 is aligned with the needle electrode 404 and the plate electrode 405 for observing the gas production process of the discharge fault; a flange 602 is provided on the outer side of the tempered borosilicate glass 601, and a polytetrafluoroethylene gasket 603 is provided between the flange 602 and the oil tank body 1, and the flange 602 and the tempered borosilicate glass 601 are both connected to the oil tank body 1 by screws 604.

[0052] In this optional embodiment, the heating assembly 8 includes a heating plate 801 arranged on the outside of the oil tank body 1 away from the tempered borosilicate glass 601. The outside of the heating plate 801 is provided with thermal insulation cotton 802. The heating plate 801 is used to heat the oil tank body 1. When the oil temperature in the oil tank body 1 reaches a preset temperature, the thermal insulation cotton 802 maintains a constant temperature.

[0053] Figure 2 An embodiment of the gas production method of the transformer insulating oil gas production test device of the present invention is shown.

[0054] In this optional embodiment, the gas production method of the transformer insulating oil gas production test device includes:

[0055] Step S101: Adjust the rotating disk 402 on the top of the fuel tank body 1 so that the gap between the needle electrode 404 and the plate electrode 405 reaches a preset position;

[0056] Step S102: Pour insulating oil into the box 101 until the box 101 is full, and exhaust the gas in the air bag 502. Open the two-way ball valve 501 to connect the air bag 502 with the box 101, and then connect the wires according to the discharge test circuit.

[0057] Step S103: Adjust the temperature of the heating plate 801 outside the box 101, and start the electrical fault simulation after the oil temperature inside the box 101 stabilizes;

[0058] Step S104: During the electrical fault simulation, after the voltages of the two sections of the plate are raised to the fault voltage, partial discharge simulation, low energy discharge simulation and high energy discharge simulation are performed respectively, and the amount of free gas and dissolved gas is calculated based on the discharge simulation results.

[0059] In this optional embodiment, the stable oil temperature inside the tank 101 is 60°C.

[0060] In this optional embodiment, before pouring insulating oil into the box 101, the method further includes:

[0061] The insulating oil is added into a vacuum drying oven, and the vacuum drying oven is adjusted to the preset conditions to dehydrate and degas the insulating oil.

[0062] In this optional embodiment, performing the partial discharge simulation includes:

[0063] Monitor the voltage between the two sections of the plate. When the voltage between the two sections of the plate rises to the fault voltage, oil samples are taken based on the preset sampling conditions to study the diffusion of dissolved gas at different locations.

[0064] The preset sampling conditions include:

[0065] The timing starts from the moment when the voltage between the two sections of the plate rises to the fault voltage. The oil sample is taken every preset time. A group of two tubes is taken from each sampling port. 40ml of oil sample is drawn through a 100ml syringe. The oil sample is continued to be drawn within 2 hours after the partial discharge simulation is completed.

[0066] In order to facilitate understanding of the above technical solutions of the present invention, the following describes in detail the transformer insulating oil gas production test device and gas production method in the actual process of the present invention:

[0067] like Figure 1 As shown, the fuel tank body 1 is composed of a stainless steel cylindrical box body 101 and a stainless steel cover plate 102. An O-ring is sandwiched between the cover plate 102 and the stainless steel cylinder to ensure airtightness. The cover plate 102 and the box body 101 are fixed using a quick fixing chuck 103. The tightness of the chuck is adjusted by adjusting the screws on the quick fixing chuck 103.

[0068] The cover plate 102 is provided with four threaded through-holes, one of which is located directly in the center of the cover plate 102. The needle electrode structure (electrode assembly 4) consists of a needle electrode 404, a threaded brass fixing post 401, and a rotating disk 402. The needle electrode 404 extends through the threaded through-hole. The threads on the surface of the brass fixing post 401 connect to the threaded through-hole in the center of the cover plate 102. The rotating disk 402 drives the brass fixing post 401 to rotate, thereby adjusting the gap between the needle electrode 404 and the plate electrode 405. A ceramic insulating sleeve 403 is installed at the connection between the brass fixing post 401 and the outside of the box 101. The output end of the needle electrode 404 is connected between the rotating disk 402 and the ceramic insulating sleeve 403.

[0069] The other three threaded holes on the cover plate 102 are connected to the exhaust check valve 3, the pressure gauge 2, and the two-way ball valve 501, respectively. The other side of the two-way ball valve 501 is connected to the airbag 502 via a quick-connect mechanism. The exhaust check valve 3 is used to balance the internal pressure when it exceeds the standard, preventing damage to the box 101 due to excessive pressure. The pressure gauge 2 is used to measure the internal pressure of the box 101. The two-way ball valve 501 is connected to the airbag 502 to collect free gas. The airbag 502 is equipped with a knob switch to ensure the airtightness of the airbag 502 when it is removed from the two-way ball valve 501. To make it easier for free gas to flow to the airbag 502, the cover plate 102 is machined into a conical gas collection structure (gas collection hole 503) inside the through hole connecting the cover plate 102 to the two-way ball valve 501.

[0070] Three equally spaced threaded holes are provided in the upper, middle, and lower sections of the sidewall of the tank 101. These holes are connected to a three-way ball valve 7 for extracting oil samples from the upper, middle, and lower layers of the tank. A hole is opened on the other side of the sidewall of the tank 101 to connect a stainless steel flange sight glass assembly 6, which is aligned with the needle electrode 404 and plate electrode 405 in the tank 101 to observe the gas production process during a discharge fault. The stainless steel flange sight glass assembly 6 consists of a flange 602, tempered borosilicate glass 601, and a polytetrafluoroethylene gasket 603. This provides observation while ensuring structural strength and sealing. The flange 602, tempered borosilicate glass 601, and the tank 101 are all secured together with screws 604.

[0071] A threaded through-hole is provided at the center of the bottom of the box 101, connecting the plate electrode 405 structure. The plate electrode 405 structure consists of the plate electrode 405 and a second brass fixing post 406, which is threaded through the through-hole and fixed with a thread. A second ceramic insulating sleeve 407 is installed at the connection between the second brass fixing post 406 and the outside of the box 101. The output end of the plate electrode is connected to the second brass fixing post 406 below the second ceramic insulating sleeve 407. The outer side wall of the box 101 is surrounded by a heating plate 801, which is wrapped with thermal insulation 802. The heating plate 801 is used to heat the box 101 to the specified temperature of the oil inside the box 101, and the thermal insulation 802 is used to maintain a constant temperature.

[0072] Based on the CMII (CIGRE Method II) electrode system structure, the electrode structure model is used to simulate corona discharge (partial discharge) and pure oil breakdown and oil-paper insulation breakdown. The discharge test circuit is as follows: Figure 2 shown.

[0073] The main principle of the CMII method is based on evaluating the performance of the grounding system through soil resistance measurement, which includes the following aspects:

[0074] Four-electrode configuration: The CMII method uses a four-electrode measurement method, which uses four electrodes to measure resistance. It usually includes:

[0075] Two current electrodes (I electrodes): used to apply current.

[0076] Two voltage electrodes (V electrodes): used to measure voltage difference.

[0077] This configuration can avoid interference with the measurement results caused by the contact resistance between the current electrode and the voltage electrode.

[0078] Current source and voltage measurement: By injecting a known current into the electrode system, the voltage difference caused is measured using a voltage electrode, and then the resistance value is calculated according to Ohm's law (V = I × R).

[0079] Soil resistivity calculation: Based on the measured voltage difference and current, combined with the soil geometry (electrode spacing, soil layer thickness, etc.), the CMII method can calculate the soil resistivity. The value of soil resistivity is crucial for evaluating the performance of the grounding system.

[0080] Measurement accuracy: The CMII method reduces errors caused by factors such as soil heterogeneity and current distribution near the ground electrode by improving the configuration and position of current electrodes and voltage electrodes during the measurement process, thereby improving the accuracy of measurement results.

[0081] exist Figure 3 In the figure, the test power supply consists of an autovoltage regulator T1 and a power frequency non-partial discharge test transformer T2, with a rated voltage of 60kV and a rated capacity of 60kVA. The protection resistor R has a resistance of 5.3kΩ and a rated voltage of 60kV. When the test piece breaks down, it limits the current and protects the test equipment. The coupling capacitor CK has a capacitance of 1000pF and a withstand voltage of 60kV. It serves as a coupling device in the discharge circuit and also as a voltage divider. During the test, it can perform phase correction on the partial discharge waveform. D is a Rogowski coil current sensor, which serves as a monitoring unit for the partial discharge signal. C X It is used to test the oil tank for gas production due to electrical faults; the digital oscilloscope F is used to measure partial discharge signals, display, collect and store signal waveforms. The power supply of the oscilloscope is introduced by an isolation transformer, which is mainly used to prevent accidental damage to the instrument due to increased ground potential during high-voltage testing.

[0082] The transformer insulating oil gas production test device and gas production method provided by the present invention are described in detail below with reference to specific embodiments.

[0083] Example 1:

[0084] Before the experiment, the insulating oil needs to be dehydrated and degassed by placing it in a vacuum drying oven at 90°C and 50 Pa for 24 hours. This treatment ensures that the water content in the oil sample is below the national standard.

[0085] Adjust the rotating disc on top of the oil tank so that the gap between the needle plate electrodes reaches the specified position. Pour insulating oil into the oil tank until it is full. Install the top cover and quick-fix chuck, and tighten the quick-fix chuck screws. Exhaust the air in the air bag, insert the quick-connect port of the two-way ball valve on the cover, and open the two-way ball valve switch to connect the air bag to the oil tank. Wire the device according to the discharge test circuit. Adjust the oil temperature: According to GB1094.2, the upper limit of the transformer oil temperature rise is 60K (for transformers where the oil is not in direct contact with the atmosphere). Due to the uneven temperature distribution of the transformer, the oil temperature at the top layer is higher than that at the lower layer. Considering the transformer's long-term operating environment and ambient temperature, the transformer oil temperature is controlled at approximately 60°C. Use the heater and temperature controller to adjust the temperature of the external heating plate of the oil tank. Wait until the internal oil temperature of the tank stabilizes before starting the electrical fault simulation.

[0086] After raising the voltage between the two plates to the fault voltage, partial discharge, low-energy discharge, and high-energy discharge were simulated. The experimental phenomena were observed, and the free gas volume and concentration of each gas were measured, as well as the dissolved gas concentration in oil samples at different locations. When simulating a partial discharge fault, a clear partial discharge waveform was visible on the oscilloscope. When simulating a low-energy discharge fault, a hissing sound could occasionally be heard between the plates. When simulating the partial discharge and low-energy discharge faults, start timing from the moment the fault voltage is added, take an oil sample at regular intervals, take a group from each sampling port, two tubes for each group, and slowly extract 40ml of oil sample using a 100ml syringe. Continue to take oil samples within 2 hours after the partial discharge simulation to study the diffusion of dissolved gases at different positions. The extraction operation is carried out in accordance with the oil sampling method GB7252: insert the glass syringe into the three-way ball valve interface and fix it, adjust the three-way ball valve to connect the box body with the side end valve port, flush the connecting pipeline, and then connect the syringe and the box body to flush the syringe, and then adjust the three-way ball valve to connect the syringe with the side end valve port, empty the oil sample in the syringe, and then connect the syringe with the box body to take out 40ml of oil sample. The connection operation is as follows: Figure 4 As shown, the connecting tube is connected to the syringe through a three-way ball valve. Figure 4 Figure a is a schematic diagram for flushing the connecting pipeline; Figure b is a schematic diagram for flushing the syringe; Figure c is a schematic diagram for emptying the syringe; Figure d is a schematic diagram for sampling; and Figure e is a schematic diagram for removing the syringe.

[0087] The free gas is calculated according to the Archimedean principle formula to calculate the gas collected in the gas collection bag during each sampling. The gas bag is placed in a container filled with water, and the two are placed together in a precision electronic scale. The initial volume of the gas collection bag and the volume of the gas collection bag after collecting the gas are compared and calculated. The difference between the two is the collected gas.

[0088] After the dissolved gas in the oil is balanced, the amount of free gas and dissolved gas is obtained through the oil volume and concentration at equilibrium, as well as the gas volume and concentration of each component in the airbag. For breakdown discharge faults, it is necessary to manually increase the voltage to breakdown before sampling. The timing starts after the end of the simulated normal operation, and two breakdowns are performed at regular intervals. The breakdown is completed within 1 minute. After each breakdown, oil samples are taken from 3 sampling points, and the dissolved gas in the oil is detected by gas chromatography. At the same time, the airbag is removed to measure the free gas volume. During the time when no breakdown operation is performed, the temperature remains stable. The concentration of dissolved gas in the oil is detected every 1 hour within 2 hours after the last breakdown to study the diffusion of dissolved gas at different positions. After the dissolved gas is balanced, the amount of free gas and dissolved gas is obtained through the oil volume and concentration at equilibrium, as well as the gas volume and concentration of each component in the airbag.

[0089] Example 2:

[0090] By adjusting the gap distance between the needle-plate electrodes on the basis of Example 1 and performing the same subsequent operations, different partial discharge voltages, low-energy discharge voltages and breakdown voltages can be obtained, and further the gas production patterns under different discharge energies can be obtained.

[0091] Example 3:

[0092] On the basis of Example 1, the temperature of the electric heater is adjusted to obtain different oil temperatures in the oil tank. By performing the same subsequent operations, the partial discharge voltage, low-energy discharge voltage and breakdown voltage at different temperatures can be obtained, and then the gas production law under different discharge energies can be obtained.

[0093] The present invention is not limited to the structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A transformer insulating oil gas production test device, comprising an oil tank body (1), characterized in that: A pressure gauge (2), an exhaust one-way valve (3), an electrode assembly (4) and a gas collecting assembly (5) are sequentially arranged on the top of the oil tank body (1) along the same horizontal direction; A flange sight glass assembly (6) is provided on the outer side wall of the oil tank body (1), and a plurality of three-way ball valves (7) are evenly provided along the same longitudinal direction on the side of the outside of the oil tank body (1) away from the flange sight glass assembly (6), and a heating assembly (8) is provided between the three-way ball valve (7) and the oil tank body (1).

2. The transformer insulating oil gas generation test device according to claim 1, characterized in that: The oil tank body (1) is composed of a box body (101) and a cover plate (102). The cylindrical box body (101) is arranged at the bottom end of the cover plate (102), and a fixing chuck (103) is arranged between the cylindrical box body (101) and the cover plate (102).

3. The transformer insulating oil gas generation test device according to claim 2, characterized in that: The box body (101) and the cover plate (102) are both made of stainless steel.

4. The transformer insulating oil gas generation test device according to claim 3, characterized in that: The electrode assembly (4) includes a brass fixed column (401) inserted into the middle of the top of the box (101), a rotating disk (402) is provided on the top of the brass fixed column (401), a ceramic insulating sleeve (403) is provided on the outer circumference of the brass fixed column (401), and the ceramic insulating sleeve (403) is provided on the top of the cover plate (102), and a needle electrode (404) is provided at the bottom end of the brass fixed column (401); A plate electrode (405) matching the needle electrode (404) is inserted into the inner bottom of the box (101).

5. The transformer insulating oil gas generation test device according to claim 1, characterized in that: The outlet end of the needle electrode (404) is connected between the rotating disk (402) and the ceramic insulating sleeve (403).

6. The transformer insulating oil gas generation test device according to claim 5, characterized in that: The outgoing end of the plate electrode (405) is connected to the outside of the brass fixing column (401) at the bottom of the ceramic insulating sleeve (403).

7. The transformer insulating oil gas generation test device according to claim 1, characterized in that: The gas collecting assembly (5) comprises a two-way ball valve (501) arranged on one side of the top of the cover plate (102), an air bag (502) is arranged on the top of the two-way ball valve (501), and a gas collecting hole (503) matching with the air bag (502) is opened on the top of the cover plate (102), and the gas collecting hole (503) is a conical structure.

8. The transformer insulating oil gas generation test device according to claim 7, characterized in that: The two-way ball valve (501) is connected to the airbag (502) for collecting free gas. When the airbag (502) is removed from the two-way ball valve (501), the airtightness of the airbag is ensured. At the same time, the top side of the cover plate (102) is set as a conical gas collection hole (503), so that the free gas can flow to the airbag (502) more easily through the gas collection hole (503).

9. The transformer insulating oil gas generation test device according to claim 4, characterized in that: The flange sight glass assembly (6) comprises a tempered borosilicate glass (601) arranged on the outer side wall of the oil tank body (1), and the tempered borosilicate glass (601) is aligned with the needle electrode (404) and the plate electrode (405) for observing the gas production process of a discharge fault; a flange (602) is provided on the outer side of the tempered borosilicate glass (601), and a polytetrafluoroethylene gasket (603) is provided between the flange (602) and the oil tank body (1).

10. The transformer insulating oil gas generation test device according to claim 9, characterized in that: The flange (602) and the tempered borosilicate glass (601) are both connected to the oil tank body (1) via screws (604).

11. The transformer insulating oil gas generation test device according to claim 1, characterized in that: The heating assembly (8) comprises a heating plate (801) arranged outside the oil tank body (1) and away from the tempered borosilicate glass (602), and a heat-insulating cotton (802) is arranged outside the heating plate (801).

12. The transformer insulating oil gas generation test device according to claim 11, characterized in that: The oil tank body (1) is heated by the heating plate (801), and when the oil temperature in the oil tank body (1) reaches a preset temperature, the temperature is kept constant by the heat-insulating cotton (802).

13. A gas production method for a transformer insulating oil gas production test device, characterized in that: The method includes: Adjusting the rotating disk (402) on the top of the oil tank body (1) so that the gap between the needle electrode (404) and the plate electrode (405) reaches a preset position; Pour insulating oil into the box (101) until the box (101) is full, and exhaust the gas in the air bag (502). Open the two-way ball valve switch (501) to connect the air bag (502) and the box (101), and then connect the wires according to the discharge test circuit. Adjusting the temperature of the heating plate (801) outside the box (101), and starting to perform the electrical fault simulation after the oil temperature inside the box (101) stabilizes; During the electrical fault simulation, after the voltage of the two sections of the plate is raised to the fault voltage, partial discharge simulation, low-energy discharge simulation and high-energy discharge simulation are performed respectively, and the amount of free gas and dissolved gas is calculated based on the discharge simulation results.

14. The gas production method of the transformer insulating oil gas production test device according to claim 13, characterized in that: The stable oil temperature inside the box (101) is 60°C.

15. The gas generation method of the transformer insulating oil gas generation test device according to claim 14, characterized in that: Before pouring insulating oil into the box (101), the method further includes: The insulating oil is added into a vacuum drying oven, and the vacuum drying oven is adjusted to the preset conditions to dehydrate and degas the insulating oil.

16. The gas generation method of the transformer insulating oil gas generation test device according to claim 15, characterized in that: The method of performing partial discharge simulation includes: Monitor the voltage between the two sections of the plate. When the voltage between the two sections of the plate rises to the fault voltage, oil samples are taken based on the preset sampling conditions to study the diffusion of dissolved gas at different locations. The preset sampling conditions include: The timing starts from the moment when the voltage between the two sections of the plate rises to the fault voltage. The oil sample is taken every preset time. A group of two tubes is taken from each sampling port. 40ml of oil sample is drawn through a 100ml syringe. The oil sample is continued to be drawn after the partial discharge simulation is completed.

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