Test tank and method for studying transformer arc pressure scale and structural effects

Abstract

The application provides a test oil tank and method for researching transformer arc pressure scale and structural effect, belongs to the field of power transformer test, and comprises an empty oil tank, a space separation component, a winding block equivalent structure and a variable position arc striking device. The space separation component is detachably connected in the empty oil tank, and the winding block equivalent structure and the variable position arc striking device are installed in the empty oil tank at intervals. The variable position arc striking device comprises a plurality of arc striking sleeves and a plurality of arc striking electrode groups. A plurality of current and voltage introduction and extraction interfaces, a plurality of pressure measurement holes and a plurality of oil injection and discharge ports are arranged on the empty oil tank. Each arc striking sleeve is installed on one current and voltage introduction and extraction interface, and the plurality of arc striking electrode groups are installed on the inner bottom wall of the empty oil tank at intervals. The application aims to solve the problem that the existing scaled-down test system cannot quantitatively describe the scale effect and structural effect of arc pressure. The technical effect is that the scale effect and structural effect of arc pressure are quantitatively described.

Description

Technical Field

[0001] This invention relates to the field of power transformer testing technology, and in particular to a test tank for studying the scale and structural effects of transformer arc pressure, and a method for using the test tank for studying the scale and structural effects of transformer arc pressure. Background Technology

[0002] With the advancement of ultra-high voltage / extra-high voltage power transmission projects, the individual capacity and internal structural complexity of large power transformers continue to increase. During transformer operation, internal breakdown caused by insulation deterioration or latent defects can generate high-energy arc discharges within microsecond to millisecond timescales. Such short-circuit faults are accompanied by extremely high power density, releasing energy up to megajoules. This enormous energy is instantly injected into the transformer oil, causing plasmaification and pyrolysis phase transitions in the oil. This energy conversion process radiates supersonic shock waves in all directions, accompanied by the periodic expansion and contraction of local high-pressure bubbles. The resulting extreme impact loads act directly on the transformer tank, exceeding its yield limit, and ultimately leading to catastrophic equipment tearing and explosion accidents.

[0003] High-energy arc faults inside large power transformers often release energy up to tens of megajoules, with the most severe faults reaching 90 megajoules within 80 milliseconds. This energy drives the transformer oil through an extremely nonlinear transient multiphase fluid dynamics evolution. However, due to the harsh environment of high voltage and high current, as well as the destructive nature of transient pressure, the dynamic evolution characteristics of high-energy arc pressure in both spatial and temporal dimensions remain unclear, making full-scale experimental research extremely difficult. Furthermore, the interior of a transformer is not a simple fluid space, but a complex barrier structure comprising the core, coils, insulating pads, and equivalent oil channels. When high-energy arc pressure propagates inside the tank, it interacts strongly with these structures through reflection, transmission, and fluid-structure interaction buffering. This complex internal boundary condition leads to extremely complex pressure wave propagation paths and energy attenuation mechanisms, making it difficult to accurately predict and quantify the final load directly acting on the tank's inner wall.

[0004] Currently, research on the distribution of electric arc pressure in oil relies heavily on scaled-down laboratory experiments, but existing studies generally focus on small-volume test tanks. While these small tanks can reveal the initial pressure characteristics of low-energy arcs, they cannot clearly define the equivalent relationship between small tanks and full-size transformers. This is mainly due to two factors: First, small tanks suffer from strong confined space wall effects, failing to provide sufficient fluid expansion margin for oil bubbles excited by high-energy arcs. During bubble expansion, they are prematurely affected by shock wave pressure reflection and wall physical constraints, making it difficult to accurately reflect the fluid dynamics characteristics within a large-scale space. Second, small tanks cannot be equipped with winding models equivalent to those of real transformers, neglecting the blocking and attenuation effects of the transformer structure on pressure waves.

[0005] In summary, the existing scaled-down test system cannot quantitatively describe the scale and structural effects of arc pressure, which means that the pressure evolution law and peak characteristics obtained from small-scale tests cannot be directly extrapolated to full-scale UHV transformers. Summary of the Invention

[0006] This invention provides a test tank and method for studying the scale and structural effects of transformer arc pressure, in order to solve the above-mentioned problems in the prior art.

[0007] The first aspect of the present invention provides a test oil tank for studying the scale and structural effect of transformer arc pressure, including an empty oil tank, a space separation component, a winding blocking equivalent structure and a variable position arc ignition device. The space separation component is detachably connected to the empty oil tank, and the winding blocking equivalent structure and the variable position arc ignition device are installed alternately in the empty oil tank. The variable position arc ignition device includes multiple arc ignition sleeves and multiple arc ignition electrode groups. The empty oil tank is equipped with multiple current and voltage input / output interfaces, multiple pressure measurement holes, and multiple oil injection / discharge ports. Each arc-starting bushing is installed on a current and voltage input / output interface, and multiple arc-starting electrode groups are installed at equal intervals on the bottom wall inside the empty oil tank.

[0008] In addition, the test tank for studying the arc pressure scale and structural effect of a transformer according to the present invention may also have the following additional technical features: In some embodiments of the present invention, the space partition assembly includes a space partition plate, a first stop block, and a second stop block. The first stop block is installed on the inner bottom wall of the empty fuel tank, and the second stop block is installed on the inner top wall of the empty fuel tank. The first stop block and the second stop block are arranged opposite to each other. The upper end of the space partition plate is inserted into the first stop block, and the lower end of the space partition plate is inserted into the second stop block.

[0009] In some embodiments of the present invention, the winding blocking equivalent structure includes an insulating connecting seat, a plurality of cylinders, a first connecting block and a plurality of second connecting blocks. The insulating connecting seat is installed on the inner bottom wall of the empty oil tank. The plurality of cylinders are spaced apart from bottom to top. The cylinder at the bottommost end is installed on the insulating connecting seat. Each pair of adjacent cylinders is connected by at least one first connecting block. At least one second connecting block is provided between the cylinder at the topmost end and the top wall of the empty oil tank. An equivalent oil passage is formed between each pair of adjacent cylinders.

[0010] In some embodiments of the present invention, each arc-initiating electrode group includes an electrode support and an arc-initiating electrode. The electrode support is installed on the inner bottom wall of the empty oil tank, and the arc-initiating electrode is installed on the upper end of the electrode support.

[0011] In some embodiments of the present invention, each electrode support includes an electrode support rod and a reinforcing support rod. The electrode support rod is installed on the inner bottom wall of the empty oil tank, the arc-starting electrode is installed on the upper end of the electrode support rod, one end of the reinforcing support rod is fixedly connected to the electrode support rod, and the other end of the reinforcing support rod is fixedly connected to the inner bottom wall of the empty oil tank.

[0012] In some embodiments of the present invention, the empty fuel tank is also provided with a manhole, an optical observation window and a pressure relief valve opening, and the manhole is covered with a cover plate.

[0013] In some embodiments of the present invention, the empty fuel tank includes a fuel tank body, an upper cover plate and a base. The upper cover plate is installed at the upper end of the fuel tank body, and the base is installed at the lower end of the fuel tank body. A first stop block is installed on the upper cover plate, and a second stop block is installed on the base. Multiple arc-starting electrode groups are installed on the base at equal intervals.

[0014] In some embodiments of the present invention, the fuel tank body includes a main shell, a lower connecting plate and an upper connecting plate. The lower connecting plate is installed at the lower end of the main shell, the upper connecting plate is installed at the upper end of the main shell, the upper cover plate is installed on the upper connecting plate, and the base is installed on the lower connecting plate.

[0015] In some embodiments of the present invention, the main body of the fuel tank further includes a first reinforcing rib and a second reinforcing rib, both of which are mounted on the main housing and are perpendicular to each other.

[0016] The second aspect of this invention provides a method for using a test tank for studying the scale and structural effects of transformer arc pressure. This method utilizes all the technical features of the test tank for studying the scale and structural effects of transformer arc pressure according to the first aspect of this invention, and further includes the following steps: Step S100: Close the manhole cover of the empty oil tank, inject transformer oil into the main body of the oil tank through the oil inlet and outlet, connect the special pipeline to complete the oil circulation and complete the vacuum degassing process; Step S200: After sealing the arc-starting sleeve at the current and voltage input / output interface, connect the arc-starting sleeve to the test power supply, install a high-frequency dynamic pressure sensor at the pressure measurement hole, and install a high-speed camera at the optical observation window at the center and side of the manhole cover. Step S200: Open the top cover, insert the space partition plate along the slot, and divide the tank body into independent test spaces of corresponding scale by adjusting the position of the space partition plate, and select the arc-starting electrode group corresponding to the geometric center of the current independent test space. Step S300: Adjust the test power supply to trigger the arc-igniting electrode group to generate a high-energy electric arc; collect data through the pressure sensor array and high-speed camera, adjust the scale of the independent test space multiple times and repeat the test, and establish a quantitative relationship between the arc power, energy and tank scale by combining the time-domain pressure data to complete the scale effect decoupling evaluation. Step S400: Switch the arc ignition point of the arc ignition electrode group to change the relative distance between the arc ignition point and the winding blocking equivalent structure; trigger arc discharge under the set energy, collect pressure waveforms at different points, analyze the pressure integral and main frequency distortion characteristics, and reveal the nonlinear blocking mechanism of the winding against the arc shock wave and bubble pulsating pressure, so as to serve as the experimental basis for optimizing the internal structure of the transformer.

[0017] In summary, this application includes the following beneficial technical effects: the volume of the effective arcing space in this test tank can be adjusted through the space separation component, constructing independent test spaces of different scales; the physical blocking effect of the real transformer winding on the arc pressure wave can be accurately simulated through the winding blocking equivalent structure; the arcing position can be flexibly adjusted through multiple arc-initiating bushings and arc-initiating electrode groups, changing the relative spatial distance between the arc pressure source and the winding blocking equivalent structure.

[0018] Therefore, this test tank safely and equivalently simulates high-energy arc faults in UHV transformers under laboratory conditions. Through multi-dimensional spatial and positional adjustments, it reveals the scale and structural effects of high-energy arc pressure in oil, providing a key basis for the design and optimization of transformer explosion-proof structures. It can also quantitatively describe the scale and structural effects of arc pressure, allowing the pressure evolution laws and peak characteristics obtained from small-scale tests to be directly extrapolated to full-size UHV transformers. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A first perspective view of a test tank for studying the scale and structural effects of transformer arc pressure according to some embodiments of the present invention is shown schematically.

[0020] Figure 2 A second perspective view of a test tank for studying the scale and structural effects of transformer arc pressure according to some embodiments of the present invention is shown schematically.

[0021] Figure 3 The diagram schematically shows a third perspective view of a test tank for studying the arc pressure scale and structural effects of a transformer according to some embodiments of the present invention.

[0022] Figure 4 A perspective view of a test tank without a main body and top cover plate is shown schematically in the study of transformer arc pressure scale and structural effects according to some embodiments of the present invention.

[0023] Figure 5 A perspective view of the arc-initiating electrode assembly of a test tank for studying the arc pressure scale and structural effects of a transformer according to some embodiments of the present invention is shown.

[0024] Figure 6 The diagram schematically shows a front view of a test tank without the main body and top cover plate in a study of the transformer arc pressure scale and structural effects according to some embodiments of the present invention.

[0025] Figure 7 A perspective view of the winding blocking equivalent structure of the arc-scale structural effect within a transformer according to some embodiments of the present invention is schematically shown.

[0026] Figure 8 A perspective view schematically illustrating the connection between the empty tank and the spatial separation assembly of a test tank for studying the arc pressure scale and structural effects of a transformer according to some embodiments of the present invention.

[0027] Figure 9 A perspective view of an empty oil tank without a top cover is shown schematically, for a study of the arc pressure scale and structural effects of a transformer according to some embodiments of the present invention.

[0028] Figure label: 1. Empty fuel tank; 11. Fuel tank body; 111. Main shell; 112. Lower connecting plate; 113. Upper connecting plate; 114. First reinforcing rib; 115. Second reinforcing rib; 116. Local reinforcing rib; 12. Upper cover plate; 13. Base; 131. First horizontal support rod; 132. Longitudinal support rod; 133. Second horizontal support rod; 134. Base plate; 101. Current and voltage inlet / outlet interface; 102. Pressure measuring hole; 103. Manhole; 104. Optical observation window; 105. Fuel filling / draining port. 106. Pressure relief valve reserved port; 2. Space partition plate; 21. First stop block; 22. Second stop block; 23. Slot; 3. Winding blocking equivalent structure; 31. First connecting block; 32. Cylinder; 33. Second connecting block; 34. Equivalent oil passage; 35. Insulating connecting seat; 4. Variable position arc ignition device; 41. Arc ignition sleeve; 42. Arc ignition electrode; 43. Electrode support; 431. Electrode support rod; 432. Reinforcing support rod; 44. First clamping block; 45. Second clamping block. Detailed Implementation

[0029] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0030] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” used herein may also refer to the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a specific order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0031] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0032] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may also be rotated 90 degrees or in other orientations, and the spatial relative descriptors used in the text will be interpreted accordingly.

[0033] like Figures 1 to 9 As shown, according to an embodiment of the first aspect of the present invention, a test tank for studying the arc pressure scale and structural effect of a transformer is proposed, comprising an empty tank 1, a space separation component, a winding blocking equivalent structure 3, and a variable position arc ignition device 4. The space separation component is detachably connected to the empty tank 1, and the winding blocking equivalent structure 3 and the variable position arc ignition device 4 are installed at intervals in the empty tank 1. The variable position arc ignition device 4 includes multiple arc ignition sleeves 41 and multiple arc ignition electrode groups. The empty oil tank 1 is equipped with multiple current and voltage input / output interfaces 101, multiple pressure measuring holes 102 and multiple oil injection / discharge ports 105. Each arc-starting sleeve 41 is mounted on a current and voltage input / output interface 101, and multiple arc-starting electrode groups are mounted at equal intervals on the bottom wall inside the empty oil tank 1.

[0034] In the above embodiments, it should be noted that the empty oil tank 1 contains insulating oil and is used to conduct the arc test; the space separation component is used to divide the internal space of the empty oil tank 1 into at least two test spaces according to the experimental needs to adjust the volume of the effective arc space; the winding blocking equivalent structure 3 is used to simulate the physical blocking and fluid channel effect of the transformer winding structure on the pressure wave; the variable position arc ignition device 4 is used to adjust the arc generation position and change the relative spatial distance between the pressure source and the blocking structure, thereby simulating the influence mechanism of the transformer structure on the propagation of the pressure wave and its dynamic relationship with the spatial distance.

[0035] The arc-initiating bushing 41 is used to introduce an external high-energy test power supply to ignite an electric arc; the top and side walls of the control tank are equipped with pressure measurement holes 102, which are used to measure the transient pressure wave of the electric arc at key locations in the empty tank 1; the top and side walls of the empty tank 1 are equipped with oil injection and discharge ports 105, which are used for the injection and discharge of transformer oil before and after the test, as well as for oil circulation and vacuum degassing treatment in conjunction with a dedicated pipeline; the dedicated pipeline is a vacuum oil filtration circulation pipeline, which includes a vacuum pumping branch and an oil circulation branch. One end is connected to the oil injection and discharge port 105, and the other end is connected to an external vacuum degassing and oil filtration device, which can realize closed-loop circulation purification of insulating oil in the tank and vacuum degassing of the cavity.

[0036] The technical effects achieved by the above embodiments are as follows: the volume of the effective arcing space can be adjusted by the space separation component of this test tank, and independent test spaces of different scales can be constructed; the physical blocking effect of the real transformer winding on the arc pressure wave can be accurately simulated by the winding blocking equivalent structure 3; the arcing position can be flexibly adjusted by multiple arc-initiating bushings 41 and arc-initiating electrode groups, and the relative spatial distance between the arc pressure source and the winding blocking equivalent structure 3 can be changed.

[0037] Therefore, this test tank safely and equivalently simulates high-energy arc faults in UHV transformers under laboratory conditions. Through multi-dimensional spatial and positional adjustments, it reveals the scale and structural effects of high-energy arc pressure in oil, providing a key basis for the design and optimization of transformer explosion-proof structures. It can also quantitatively describe the scale and structural effects of arc pressure, allowing the pressure evolution laws and peak characteristics obtained from small-scale tests to be directly extrapolated to full-size UHV transformers.

[0038] Optional, such as Figure 8 and Figure 9 As shown, the space partition assembly includes a space partition plate 2, a first stop block 21, and a second stop block 22. The first stop block 21 is installed on the inner bottom wall of the empty fuel tank 1, and the second stop block 22 is installed on the inner top wall of the empty fuel tank 1. The first stop block 21 and the second stop block 22 are arranged opposite to each other. The upper end of the space partition plate 2 is inserted into the first stop block 21, and the lower end of the space partition plate 2 is inserted into the second stop block 22.

[0039] In the above optional embodiments, it should be noted that the inner bottom wall of the empty fuel tank 1 is equipped with a plurality of first blocks 21 along the length direction by means of screwing or welding, and the inner top wall is equipped with a plurality of second blocks 22 along the length direction by means of the same means; the plurality of first blocks 21 and the plurality of second blocks 22 correspond one to one and are arranged opposite to each other, and each first block 21 and second block 22 is provided with a slot 23, the upper end of the space partition plate 2 is inserted into the slot 23 of the corresponding first block 21, and the lower end of the space partition plate 2 is inserted into the slot 23 of the corresponding second block 22; the thickness of the space partition plate 2 is equal to the thickness of the side wall of the empty fuel tank 1.

[0040] The advantages of the above optional embodiments are: by setting the space partition, the internal space of the tank body 11 can be divided into independent test spaces of different sizes, thereby realizing the multi-dimensional adjustment of the test space.

[0041] Optional, such as Figures 1 to 4 and Figure 6 and Figure 7 As shown, the winding blocking equivalent structure 3 includes an insulating connecting seat 35, multiple cylinders 32, a first connecting block 31, and multiple second connecting blocks 33. The insulating connecting seat 35 is installed on the inner bottom wall of the empty oil tank 1. The multiple cylinders 32 are spaced apart from bottom to top. The cylinder 32 at the bottom end is installed on the insulating connecting seat 35. Each pair of adjacent cylinders 32 is connected by at least one first connecting block 31. At least one second connecting block 33 is provided between the uppermost cylinder 32 and the top wall of the empty oil tank 1. An equivalent oil passage 34 is formed between each pair of adjacent cylinders 32.

[0042] In the above optional embodiments, it should be noted that each cylinder 32 is a rigid cylinder 32, and multiple cylinders 32 are sequentially welded together from top to bottom along the axial direction through the first connecting block 31. An equivalent oil channel 34 is formed between two adjacent cylinders 32, and the flow area and proportion of each equivalent oil channel 34 are matched with the area and proportion of the equivalent oil channel 34 of the real transformer winding. The outer periphery of each cylinder 32, the outer periphery of each first connecting block 31, and the outer periphery of each second connecting block 33 are all covered with insulating paper to construct an equivalent oil-paper composite fluid-structure coupling interface.

[0043] Each cylinder 32 is a steel cylinder, and each first connecting block 31 and each second connecting block 33 are steel blocks.

[0044] The winding blocking equivalent structure 3 is based on the principle that the macroscopic porosity is equivalent to the dynamic leakage area. By adjusting the area of ​​the equivalent oil channel 34, the proportion of the permeable area of ​​the equivalent oil channel 34 is controlled within the proportion range of the real transformer winding. Insulating paper is wrapped around the outside of the cylinder 32 to restore the oil paper composite interface.

[0045] The advantages of the above optional embodiments are as follows: the winding blocking equivalent structure 3 achieves overall insulation and fixation through the insulating connecting seat 35, the multi-layer cylinder 32 is arranged in layers at intervals, and the standardized equivalent oil channel 34 is formed by the support and separation of the first connecting block 31. The top layer second connecting block 33 limits the upper cylinder 32, and the overall structure is stable and reliable.

[0046] The adjustable gap between the multi-layered cylindrical sections 32 and the equivalent oil channel 34 allow for the replication of the flow channel porosity characteristics of a real transformer winding. The outer layer can be covered with insulating paper to simulate the oil-paper composite interface, restoring the actual fluid-structure interaction boundary. When the pressure wave generated by the electric arc passes through the equivalent oil channel 34, some energy is transmitted and some is reflected by the rigid wall of the cylindrical section 32. The segmented structure can exhibit the energy absorption and buffering effect of small deformations under impact, realistically replicating the nonlinear blocking and attenuation effect of the winding on the arc shock wave and bubble pulsating pressure, effectively improving the authenticity and reference value of the arc structure effect test data.

[0047] Optional, such as Figures 1 to 5 As shown, each arc-starting electrode group includes an electrode support 43 and an arc-starting electrode 42. The electrode support 43 is installed on the inner bottom wall of the empty oil tank 1, and the arc-starting electrode 42 is installed on the upper end of the electrode support 43.

[0048] In the above optional embodiments, it should be noted that the number of arc-initiating electrode groups is four, and the four arc-initiating electrode groups are arranged at equal intervals along the length of the inner bottom wall of the empty oil tank 1.

[0049] Each arc-starting electrode group includes two oppositely arranged electrode supports 43 and two oppositely arranged arc-starting electrodes 42. Each electrode support 43 is installed on the inner bottom wall of the empty oil tank 1, and an arc-starting electrode 42 is installed at the upper end of each electrode support 43.

[0050] Optional, such as Figures 1 to 5 As shown, each electrode support 43 includes an electrode support rod 431 and a reinforcing support rod 432. The electrode support rod 431 is installed on the inner bottom wall of the empty oil tank 1, and the arc-starting electrode 42 is installed on the upper end of the electrode support rod 431. One end of the reinforcing support rod 432 is fixedly connected to the electrode support rod 431, and the other end of the reinforcing support rod 432 is fixedly connected to the inner bottom wall of the empty oil tank 1.

[0051] In the above optional embodiments, it should be noted that each electrode support 43 includes two electrode support rods 431 spaced apart on the inner bottom wall of the empty oil tank 1, two reinforcing support rods 432, a first clamping block 44 and a second clamping block 45. One end of each reinforcing support rod 432 is fixedly connected to one electrode support rod 431, and the other end of each reinforcing support rod 432 is fixedly connected to the inner bottom wall of the empty oil tank 1. One end of the first clamping block 44 is welded and screwed to the upper end of one of the electrode support rods 431, and the other end of the first clamping block 44 is welded and screwed to the upper end of the other electrode support rod 431. The second clamping block 45 is mounted on the first clamping block 44, and the arc-initiating electrode 42 is clamped between the second clamping block 45 and the first clamping block 44. The reinforcing support rods 432 are used to improve the strength of the high-energy impact structure.

[0052] The advantages of the above optional embodiments are as follows: by fixing the arc-initiating electrode 42 to the electrode bracket 43 on the bottom wall inside the oil tank, the installation posture and height stability of the arc-initiating electrode 42 can be effectively maintained, thereby calibrating the arc ignition position in different test spaces within the main body of the oil tank 11, ensuring that the position of the arc source is controllable and reproducible, effectively avoiding test deviations caused by electrode shaking, and providing a stable and reliable shock wave pressure source for high-energy arc comparison tests under different scales and structural conditions.

[0053] Optional, such as Figures 1 to 3 As shown, the empty oil tank 1 is also equipped with a manhole 103, an optical observation window 104 and a pressure relief valve reserved port 106, and the manhole 103 is covered with a cover plate.

[0054] In the above optional embodiments, it should be noted that the manhole 103 is used for the internal arc-starting electrode 42 arrangement, test circuit wiring, etc.; the optical observation window 104 is used to capture the transient arc morphology from multiple angles and macroscopically record the fluid evolution process of bubble expansion; the pressure relief valve reserved port 106 is opened on the top surface of the oil tank, and the pressure relief valve reserved port 106 is used to install the pressure relief valve to ensure the pressure relief safety of the oil tank under extreme overpressure conditions.

[0055] Optional, such as Figures 1 to 3 as well as Figure 8 and Figure 9 As shown, the empty oil tank 1 includes an oil tank body 11, an upper cover plate 12 and a base 13. The upper cover plate 12 is installed at the upper end of the oil tank body 11, and the base 13 is installed at the lower end of the oil tank body 11. A first stop block 21 is installed on the upper cover plate 12, and a second stop block 22 is installed on the base 13. Multiple arc-starting electrode groups are installed on the base 13 at equal intervals.

[0056] In the above optional embodiments, it should be noted that the base 13 includes a first horizontal support rod 131, a longitudinal support rod 132, a second horizontal support rod 133 and a base plate 134. The base plate 134 is installed at the lower end of the oil tank body 11. The first horizontal support rod 131, the longitudinal support rod 132 and the second horizontal support rod 133 are provided on the lower side of the base plate 134 to ensure the support strength.

[0057] Optional, such as Figures 1 to 3 as well as Figure 8 and Figure 9 As shown, the main body 11 of the fuel tank includes a main shell 111, a lower connecting plate 112 and an upper connecting plate 113. The lower connecting plate 112 is installed at the lower end of the main shell 111, the upper connecting plate 113 is installed at the upper end of the main shell 111, the upper cover plate 12 is installed on the upper connecting plate 113, and the base 13 is installed on the lower connecting plate 112.

[0058] In the above optional embodiments, it should be noted that the lower connecting plate 112 is welded to the lower end of the main housing 111, and the upper connecting plate 113 is welded to the upper end of the main housing 111.

[0059] The upper cover plate 12 is provided with current and voltage input and output interfaces 101 and 105, oil injection and discharge ports 105 and 106, and pressure relief valve reserved port 106; the side wall of the main housing 111 is provided with pressure measuring holes 102 and 103, manhole 103 and optical observation window 104.

[0060] Optional, such as Figures 1 to 3 as well as Figure 8 and Figure 9 As shown, the main body 11 of the fuel tank also includes a first reinforcing rib 114 and a second reinforcing rib 115. The first reinforcing rib 114 and the second reinforcing rib 115 are both installed on the main housing 111, and the first reinforcing rib 114 and the second reinforcing rib 115 are perpendicular to each other.

[0061] In the above optional embodiments, it should be noted that a local reinforcing rib 116 is also included. A local reinforcing rib 116 is provided on the outer periphery of the pressure measuring hole 102 on the side wall of the main housing 111. The local reinforcing rib 116 is used to compensate for the decrease in local structural strength caused by large-sized openings and dense measuring point openings, and effectively prevents the empty oil tank 1 from tearing due to stress concentration.

[0062] The beneficial effects of the above optional embodiments are that the cooperation of the first reinforcing rib 114 and the second reinforcing rib 115 can effectively improve the high pressure resistance of the empty oil tank 1.

[0063] According to an embodiment of the second aspect of the present invention, a method for studying the experimental oil tank of a transformer arc pressure scale and structural effect is proposed, comprising the following steps: Step S100: Close the manhole 103 cover of the empty oil tank 1, inject transformer oil into the main body 11 of the oil tank through the oil inlet / outlet port 105, connect the special pipeline to complete the oil circulation and complete the vacuum degassing process. Step S200: After sealing the arc-starting sleeve 41 at the current and voltage input / output interface 101, connect the arc-starting sleeve 41 to the test power supply, install a high-frequency dynamic pressure sensor at the pressure measurement hole 102, and install a high-speed camera at the center and side optical observation window 104 of the manhole 103 cover plate. Step S200: Open the upper cover plate 12, insert the space partition plate 2 along the slot 23, and divide the oil tank body 11 into independent test spaces of corresponding sizes by adjusting the position of the space partition plate 2, and select the arc-starting electrode group corresponding to the geometric center of the current independent test space. Step S300: Adjust the test power supply to trigger the arc-igniting electrode group to generate a high-energy electric arc; collect data through the pressure sensor array and high-speed camera, adjust the scale of the independent test space multiple times and repeat the test, and establish a quantitative relationship between the arc power, energy and tank scale by combining the time-domain pressure data to complete the scale effect decoupling evaluation. Step S400: Switch the arc ignition point of the arc ignition electrode group to change the relative distance between the arc ignition point and the winding blocking equivalent structure 3; trigger arc discharge under the set energy, collect pressure waveforms at different points, analyze the pressure integral and main frequency distortion characteristics, and reveal the nonlinear blocking mechanism of the winding against the arc shock wave and bubble pulsating pressure, so as to serve as the experimental basis for the optimization of the transformer internal structure.

[0064] In the above optional embodiments, it should be noted that in step S100, the dedicated pipeline is the existing oil circulation pipeline.

[0065] Step S200: Open the upper cover plate 12, insert the space partition plate 2 along the slot 23, and divide the oil tank body 11 into independent test spaces of corresponding dimensions by adjusting the position of the space partition plate 2. Select the arc-starting electrode group corresponding to the geometric center of the current independent test space, including: Open the top cover 12 of the oil tank and insert a removable space partition with a thickness consistent with the oil tank wall thickness along the baffle groove on the inner wall of the oil tank. By flexibly changing the position of the partition, the main body of the oil tank 11 is physically divided into independent test spaces with dimensions of 0.5m, 1m, or 2m. Subsequently, the arc-initiating electrode 42 support located at the geometric center of the currently set independent space is strictly selected. For example, when the space is set to 0.5m, 1m, and 2m, the first, third, and fourth arc-initiating support groups are activated respectively to ensure that the position of the arc relative to the fluid boundary is completely consistent when studying at different scales.

[0066] Step S300: Adjust the test power supply to trigger the arc-igniting electrode group to generate a high-energy arc; collect data through a pressure sensor array and a high-speed camera, adjust the scale of the independent test space multiple times and repeat the test, and establish a quantitative relationship between arc power, energy and tank scale by combining time-domain pressure data, completing the scale effect decoupling evaluation, including: According to Buckingham's π theorem, the spatial energy density at corresponding positions in the full-size model and the scaled-down model is kept equivalent. An external pulse or power frequency high-energy test power supply is adjusted to trigger the arc-igniting electrode group to generate a high-energy arc. The total arc energy injected into the main body 11 of the oil tank is strictly scaled down according to the cube of the current test space geometric scaling factor λ.

[0067] A high-energy electric arc is released by triggering the arc-ignition system, and the dynamic evolution of the arc is recorded using a pressure sensor array and a high-speed camera arranged on the tank wall. According to the scaling principle, under the condition of energy scaling by the cube of λ, the kinetic energy of the plasma shock wave expansion and the pulsation period of the first expansion of the bubble are theoretically reduced by a factor of λ. By repeating the above experimental operation by changing the position of the baffle in multiple rounds, time-domain pressure data under different constraint volumes are obtained, and then a quantitative scaling relationship between arc power, energy injection and tank scale is established, completing the decoupled evaluation of scale effects.

[0068] Step S400: Switch the arc ignition point of the arc ignition electrode group to change the relative distance between the arc ignition point and the winding blocking equivalent structure 3; trigger arc discharge under a set energy, collect pressure waveforms at different points, analyze the pressure integral and main frequency distortion characteristics, and reveal the nonlinear blocking mechanism of the winding against the arc shock wave and bubble pulsating pressure. This serves as the experimental basis for optimizing the internal structure of the transformer, including: By using multiple pre-set arc-initiating electrode groups inside the main body 11 of the oil tank, the relative geometric distance between the actual arc ignition point pressure source and the winding blocking equivalent structure 3 can be artificially changed by switching the connection or triggering position of the arc-initiating copper wire.

[0069] The arc ignition point refers to the stable ignition point required for the stable combustion of the arc at the guide electrode.

[0070] Arc discharge was triggered at a set energy level, and pressure waveform characteristics were simultaneously acquired from the winding circumferential surface, the oil tank wall on the back side of the winding, and the direct-impact wall using a pressure measurement array. When the pressure wave reached the equivalent structure of the winding, part of the energy was transmitted inward through the equivalent oil channel 34 and scattered, while another part of the energy was totally reflected due to the obstruction of the rigid cylinder 32. At the same time, the small deformation of the segmented structure wrapped with insulating paper under transient impact could play a fluid-structure interaction energy absorption buffering role. By comparing the pressure integral and main frequency distortion characteristics at different arc-initiating distances and different observation points, the nonlinear blocking mechanism of the transformer winding against shock waves and bubble pulsating pressure was revealed, thus providing direct experimental criteria for optimizing the structural strength and spatial layout of internal structural components of UHV transformers.

[0071] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A test tank for studying the scale and structural effects of transformer arc pressure, characterized in that, It includes an empty oil tank (1), a space separation component, a winding blocking equivalent structure (3) and a variable position arc-starting device (4). The space separation component is detachably connected to the empty oil tank (1), and the winding blocking equivalent structure (3) and the variable position arc-starting device (4) are installed in the empty oil tank (1) at intervals. The variable position arc ignition device (4) includes multiple arc ignition sleeves (41) and multiple arc ignition electrode groups. The empty oil tank (1) is provided with multiple current and voltage input and output interfaces (101), multiple pressure measurement holes (102) and multiple oil injection and discharge ports (105). Each of the arc-starting sleeves (41) is mounted on a current and voltage input / output interface (101), and multiple arc-starting electrode groups are mounted at equal intervals on the bottom wall inside the empty oil tank (1).

2. The test tank for studying the transformer arc pressure scale and structural effect according to claim 1, characterized in that, The space partition assembly includes a space partition plate (2), a first stop (21) and a second stop (22). The first stop (21) is installed on the inner bottom wall of the empty oil tank (1), and the second stop (22) is installed on the inner top wall of the empty oil tank (1). The first stop (21) and the second stop (22) are arranged opposite to each other. The upper end of the space partition plate (2) is inserted into the first stop (21), and the lower end of the space partition plate (2) is inserted into the second stop (22).

3. The test tank for studying the transformer arc pressure scale and structural effect according to claim 1, characterized in that, The winding blocking equivalent structure (3) includes an insulating connector (35), a plurality of cylinders (32), a first connecting block (31) and a plurality of second connecting blocks (33). The insulating connector (35) is installed on the inner bottom wall of the empty oil tank (1). The plurality of cylinders (32) are spaced apart from bottom to top. The cylinder (32) at the bottom end is installed on the insulating connector (35). Each pair of adjacent cylinders (32) is connected by at least one first connecting block (31). At least one second connecting block (33) is provided between the cylinder (32) at the top end and the top wall of the empty oil tank (1). An equivalent oil passage (34) is formed between each pair of adjacent cylinders (32).

4. The test tank for studying the transformer arc pressure scale and structural effect according to claim 1, characterized in that, Each of the arc-initiating electrode groups includes an electrode support (43) and an arc-initiating electrode (42), the electrode support (43) being mounted on the inner bottom wall of the empty oil tank (1), and the arc-initiating electrode (42) being mounted on the upper end of the electrode support (43).

5. The test tank for studying the transformer arc pressure scale and structural effect according to claim 4, characterized in that, Each of the electrode supports (43) includes an electrode support rod (431) and a reinforcing support rod (432). The electrode support rod (431) is installed on the inner bottom wall of the empty oil tank (1). The arc-starting electrode (42) is installed on the upper end of the electrode support rod (431). One end of the reinforcing support rod (432) is fixedly connected to the electrode support rod (431), and the other end of the reinforcing support rod (432) is fixedly connected to the inner bottom wall of the empty oil tank (1).

6. The test tank for studying the transformer arc pressure scale and structural effect according to claim 1, characterized in that, The empty oil tank (1) is also provided with a manhole (103), an optical observation window (104) and a pressure relief valve reserved port (106), and the manhole (103) is covered with a cover plate.

7. The test tank for studying the transformer arc pressure scale and structural effect according to claim 2, characterized in that, The empty oil tank (1) includes an oil tank body (11), an upper cover plate (12) and a base (13). The upper cover plate (12) is installed on the upper end of the oil tank body (11), and the base (13) is installed on the lower end of the oil tank body (11). The first stop block (21) is installed on the upper cover plate (12), and the second stop block (22) is installed on the base (13). Multiple arc-starting electrode groups are installed on the base (13) at equal intervals.

8. The test tank for studying the transformer arc pressure scale and structural effect according to claim 7, characterized in that, The main body (11) of the oil tank includes a main shell (111), a lower connecting plate (112) and an upper connecting plate (113). The lower connecting plate (112) is installed at the lower end of the main shell (111), the upper connecting plate (113) is installed at the upper end of the main shell (111), the upper cover plate (12) is installed on the upper connecting plate (113), and the base (13) is installed on the lower connecting plate (112).

9. The test tank for studying the transformer arc pressure scale and structural effect according to claim 8, characterized in that, The main body of the oil tank (11) also includes a first reinforcing rib (114) and a second reinforcing rib (115). The first reinforcing rib (114) and the second reinforcing rib (115) are both installed on the main shell (111), and the first reinforcing rib (114) and the second reinforcing rib (115) are perpendicular to each other.

10. A method for studying the experimental oil tank of a transformer arc pressure scale and structural effect, comprising using all the technical features of the experimental oil tank for studying the transformer arc pressure scale and structural effect as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step S100: Close the manhole cover of the empty oil tank (1), inject transformer oil into the main body (11) of the oil tank through the oil inlet / outlet port (105), connect the special pipeline to complete the oil circuit circulation and complete the vacuum degassing process; Step S200: After sealing the arc-starting sleeve (41) at the current and voltage input / output interface (101), connect the arc-starting sleeve (41) to the test power supply, install a high-frequency dynamic pressure sensor at the pressure measurement hole (102), and install a high-speed camera at the center and side optical observation window (104) of the manhole cover. Step S200: Open the top cover (12), insert the space partition plate (2) along the slot (23), and divide the tank body (11) into independent test spaces of corresponding scale by adjusting the position of the space partition plate (2), and select the arc-starting electrode group corresponding to the geometric center of the current independent test space. Step S300: Adjust the test power supply to trigger the arc-igniting electrode group to generate a high-energy electric arc; collect data through the pressure sensor array and high-speed camera, adjust the scale of the independent test space multiple times and repeat the test, and establish a quantitative relationship between the arc power, energy and tank scale by combining the time-domain pressure data to complete the scale effect decoupling evaluation. Step S400: Switch the arc ignition point of the arc ignition electrode group, change the relative distance between the arc ignition point and the winding blocking equivalent structure (3); trigger the arc discharge under the set energy, collect the pressure waveform at different points, analyze the pressure integral and main frequency distortion characteristics, reveal the nonlinear blocking mechanism of the winding against the arc shock wave and bubble pulsating pressure, and use this as the experimental basis for the optimization of the transformer internal structure.

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