Transformer arc fault buffer energy absorption device, transformer oil tank and determination method

Abstract

The application provides a transformer arc fault buffer energy absorption device, a transformer oil tank and a determination method. The device comprises two buffer plates and a buffer structure; the buffer structure is clamped between the two buffer plates; one of the buffer plates is in contact with a flange of the transformer oil tank; and a bolt at the flange of the transformer oil tank is threaded through the two buffer plates, the buffer structure and the flange and is screwed with a nut. In the application, the two buffer plates and the buffer structure are arranged at the connection between the flange of the transformer oil tank and the bolt, can absorb fault energy and sudden stress, reduce the tensile stress and shear stress borne by the bolt, reduce the impact stress at the position of the bolt at the flange, avoid the fracture of the bolt or the failure of the structure, do not need to consider the influence on the electric field distribution, effectively ensure the normal operation of the transformer, the device can bear the mechanical strength test of the transformer oil tank, and can meet the mechanical strength requirement and the sealing requirement of the transformer oil tank.

Description

Technical Field

[0001] This invention relates to the field of transformer oil tank technology, and more specifically, to a transformer arc fault buffer energy absorption device, a transformer oil tank, and a method for determining it. Background Technology

[0002] Transformers are among the most critical pieces of equipment in ultra-high voltage (UHV) power transmission systems. Arcing within the transformer tank can cause a rapid increase in pressure, potentially leading to tank tearing, bolt breakage, and ultimately, deflagration. The bolted connections in the transformer tank are rigid, using high-strength bolts primarily designed to withstand bending moments, axial forces, and shear forces, resulting in very high connection rigidity.

[0003] The fault pressure generated by electric arc discharge is characterized by high impact pressure and short duration. Bolted connections are often weak points in the tank structure, and the bolts at these connections primarily bear axial tensile force. To reduce the impact of fault pressure on these connections and minimize the risk of structural damage, buffer energy-absorbing structures are typically installed at locations prone to failure inside the transformer tank (such as tank wall corners, welds between the tank wall and the bottom plate, cover plates, and tank wall joints). This softens the tank and buffers the impact of fault explosions, protecting it. Without altering the original tank dimensions, the buffer energy-absorbing structure prevents fault energy from directly acting on the tank structure, thereby reducing pressure peaks and enhancing the overall explosion-proof performance of the tank. However, due to the high potential inside the transformer tank during operation, the insulation distance between the buffer energy-absorbing material and charged parts, as well as its impact on the electric field distribution, must be considered. Furthermore, under operating conditions, the air gap structure of the buffer energy-absorbing material is prone to discharge under the influence of the electric field, thus affecting the normal operation of the transformer. Summary of the Invention

[0004] In view of this, the present invention proposes a transformer arc fault buffer energy absorption device, aiming to solve the problem that placing buffer energy absorption materials inside the oil tank in the prior art can easily affect the normal operation of the transformer. The present invention also proposes a method for determining the parameters of the buffer structure in the transformer oil tank and the transformer arc fault buffer energy absorption device.

[0005] In one aspect, the present invention proposes a transformer arc fault buffer energy absorption device, which includes: two buffer plates and a buffer structure; wherein the buffer structure is sandwiched between the two buffer plates, one of the buffer plates is used to contact the flange of the transformer tank, and bolts at the flange of the transformer tank pass through the two buffer plates, the buffer structure and the flange and are screwed to the nuts.

[0006] Furthermore, in the aforementioned transformer arc fault buffer energy absorption device, the buffer structure is a honeycomb aluminum plate or a foam aluminum plate.

[0007] Furthermore, in the aforementioned transformer arc fault buffer energy absorption device, both buffer plates are aluminum plates.

[0008] Furthermore, in the above-mentioned transformer arc fault buffer energy absorption device, the buffer plate in contact with the flange is a steel plate with preset plasticity, and the other buffer plate is a steel plate with preset strength.

[0009] Furthermore, the aforementioned transformer arc fault buffer energy absorption device also includes: a reinforcing rib and an elastic element; wherein the reinforcing rib is disposed on the outside of a steel plate with a preset strength; and the elastic element is disposed between the reinforcing rib and the bolt cap.

[0010] In this invention, both buffer plates and the buffer structure are placed at the connection between the flange and the bolts of the transformer tank. This allows for the absorption of fault energy and sudden stress, reducing the tensile and shear stresses on the bolts. Furthermore, it does not alter the original internal structure of the transformer tank, reducing the impact stress at the bolt location on the flange and preventing bolt breakage or structural failure. It eliminates the need to consider the impact on the electric field distribution, effectively ensuring the normal operation of the transformer. This invention solves the problem in existing technologies where placing buffer energy-absorbing materials inside the tank can easily affect the normal operation of the transformer. The device can withstand the mechanical strength test of the transformer tank and does not undergo plastic deformation under normal operating conditions, thus meeting the mechanical strength and sealing requirements of the transformer tank.

[0011] On the other hand, the present invention also proposes a transformer oil tank, which includes: a tank body and a plurality of the above-mentioned transformer arc fault buffer energy absorption devices; wherein, each transformer arc fault buffer energy absorption device is disposed on the outside of the tank body, and each transformer arc fault buffer energy absorption device is respectively placed at the connection between the flange and the bolt of the tank body.

[0012] Since the transformer arc fault buffer energy absorption device has the above-mentioned effects, the transformer oil tank with the transformer arc fault buffer energy absorption device also has the corresponding technical effects.

[0013] Furthermore, this invention proposes a method for determining the parameters of the buffer structure in any of the aforementioned transformer arc fault buffer energy absorption devices. This method includes the following steps: a stress determination step, determining the stress borne by the transformer arc fault buffer energy absorption device based on the explosion energy of the transformer tank and the main stress-bearing areas at the buffer plate and the transformer tank flange; an adjustment step, adjusting the parameters of the buffer structure based on the stress borne by the transformer arc fault buffer energy absorption device, and obtaining multiple sets of parameter data; an analysis step, performing finite element simulation analysis on each set of parameter data to determine the stress distribution cloud map and energy dissipation curve; and a screening step, determining the parameters of the buffer structure based on the stress distribution cloud map, energy dissipation curve, and the installation conditions of the transformer tank.

[0014] Furthermore, in the above parameter determination method, in the stress determination step, when the transformer arc fault buffer energy absorption device is installed at the connecting flange, the main force-bearing area between the buffer plate and the transformer tank flange is the sum of the contact areas between each bolt cap at the connecting flange and the buffer plate in contact with it; when the transformer arc fault buffer energy absorption device is installed at the manhole cover, the main force-bearing area between the buffer plate and the transformer tank flange = the sum of the contact areas between each bolt cap at the manhole cover and the buffer plate in contact with it + the area of ​​the buffer plate in contact with the flange at the manhole cover placed inside the flange at the manhole cover.

[0015] Furthermore, in the above parameter determination method, the buffer structure is a honeycomb aluminum plate or a foam aluminum plate.

[0016] Furthermore, in the above parameter determination method, during the adjustment step, when the buffer structure is a honeycomb aluminum plate, the parameters of the honeycomb aluminum plate are cell size, cell wall thickness, and thickness of the honeycomb aluminum plate; when the buffer structure is a foamed aluminum plate, the parameters of the foamed aluminum plate are porosity and thickness of the foamed aluminum plate.

[0017] In this invention, the stress borne by the transformer arc fault buffer energy absorption device is determined based on the explosion energy of the transformer tank and the main stress-bearing areas of the buffer plate and the transformer tank flange in the transformer arc fault buffer energy absorption device. The parameters of the buffer structure are then adjusted, and multiple sets of parameter data are obtained. Finite element simulation analysis is then performed on each set of parameter data to determine the stress distribution cloud map and energy dissipation curve. Finally, the parameters of the buffer structure are determined in conjunction with the installation conditions of the transformer tank. This allows for accurate determination of the buffer structure parameters, ensuring that the transformer arc fault buffer energy absorption device has a good buffer energy absorption effect, effectively absorbing fault energy and sudden stress, reducing the tensile and shear stress borne by the bolts, and without altering the original internal structure of the transformer tank. It reduces the impact stress at the bolt location on the flange, preventing bolt breakage or structural failure, and eliminates the need to consider the impact on the electric field distribution, effectively ensuring the normal operation of the transformer. Attached Figure Description

[0018] 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:

[0019] Figure 1 This is a schematic diagram of the structure of the transformer arc fault buffer energy absorption device provided in an embodiment of the present invention;

[0020] Figure 2A schematic diagram of the buffer structure in the transformer arc fault buffer energy absorption device provided in this embodiment of the invention;

[0021] Figure 3 Another schematic diagram of the buffer structure in the transformer arc fault buffer energy absorption device provided in the embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the discharge process of the transformer arc fault buffer energy absorption device provided in an embodiment of the present invention;

[0023] Figure 5 A top view of the buffer structure in the transformer arc fault buffer energy absorption device provided in this embodiment of the invention;

[0024] Figure 6 A schematic diagram of the cell structure in the transformer arc fault buffer energy absorption device provided in this embodiment of the invention;

[0025] Figure 7 This is another structural schematic diagram of a cell in the transformer arc fault buffer energy absorption device provided in an embodiment of the present invention;

[0026] Figure 8 This is another structural schematic diagram of the cell in the transformer arc fault buffer energy absorption device provided in the embodiment of the present invention;

[0027] Figure 9 A flowchart illustrating the method for determining the parameters of the buffer structure in the transformer arc fault buffer energy absorption device provided in this embodiment of the invention. Detailed Implementation

[0028] 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 to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] Device Example:

[0030] See Figures 1 to 8The figure shows a preferred structure of the transformer arc fault buffer energy absorption device in this embodiment. As shown, the transformer arc fault buffer energy absorption device is installed outside the transformer tank. The device includes two buffer plates 1 and a buffer structure 2. The two buffer plates 1 are arranged side by side, and there is a preset distance between the two buffer plates 1. The preset distance can be determined according to the actual situation, and this embodiment does not impose any restrictions on it.

[0031] The buffer structure 2 is sandwiched between two buffer plates 1. One buffer plate 1 is used to contact the flange 3 of the transformer tank, which can be a flange at the riser, bushing flange, manhole cover, etc. The other buffer plate 1 is used to contact the bolt cap at the flange 3 of the transformer tank. The bolt 4 at the flange 3 of the transformer tank passes through the two buffer plates 1, the buffer structure 2, and the flange 3, and is screwed with a nut 5. In this way, the two buffer plates 1 and the buffer structure 2 can be fixed between the flange 3 and the bolt cap.

[0032] In practice, the installation of the buffer structure 2 needs to meet the requirements of bolt preload. The preload is based on the bolt strength grade. In this embodiment, the preload is 70% of the bolt yield strength.

[0033] As can be seen, in this embodiment, the two buffer plates 1 and the buffer structure 2 are all placed at the connection between the flange 3 and the bolt 4 of the transformer tank. They can absorb fault energy and sudden stress, reduce the tensile stress and shear stress borne by the bolt 4, and do not change the original structure inside the transformer tank. They reduce the impact stress at the location of the bolt 4 at the flange 3, avoid bolt 4 breakage or structural failure, and do not need to consider the impact on the electric field distribution. They can effectively ensure the normal operation of the transformer and solve the problem that setting buffer energy-absorbing materials inside the tank in the prior art can easily affect the normal operation of the transformer. The device can withstand the mechanical strength test of the transformer tank and does not undergo plastic deformation under normal operation of the transformer tank, thus meeting the mechanical strength and sealing requirements of the transformer tank.

[0034] See Figures 1 to 3 The buffer structure 2 is a honeycomb aluminum panel or a foam aluminum panel. The honeycomb aluminum panel is a lightweight, high-strength porous material composed of multiple cells. The porous structure of the honeycomb aluminum panel efficiently absorbs energy through plastic deformation when subjected to impact.

[0035] The cell structure can be of the negative Poisson's ratio type (see...) Figure 6 ), diamond origami pattern (see Figure 7 ), regular concave hexagon (see Figure 8 This embodiment does not impose any limitations on this.

[0036] See Figure 1 and Figure 2 The figure shows a preferred structure of the buffer plate. As shown, both buffer plates 1 are aluminum plates, with a honeycomb aluminum plate or foam aluminum plate sandwiched between them. Specifically, both buffer plates 1 are high-strength aluminum plates. Thus, the aluminum plate in contact with the bolt head ( Figure 2 The function of the aluminum plate placed at the top is to prevent deformation and transmit impact force without loss. The aluminum plate in contact with flange 3 ( Figure 2 The aluminum plate positioned below serves as a solid support. In this structure, the transformer arc fault buffer energy absorption device is located at the flange or bushing flange of the riser. In this configuration, both aluminum plates and the honeycomb aluminum plate or foam aluminum plate sandwiched between them are annular. Installation can be done as a single unit or by assembling multiple parts.

[0037] See Figure 3 The figure shows another preferred structure of the buffer plate. As shown, the buffer plate 1 in contact with flange 3 is a steel plate with a predetermined plasticity, which has good plasticity but low strength. The other buffer plate 1 is a steel plate with a predetermined strength, which is thicker and has higher strength. A honeycomb aluminum plate or foam aluminum plate is sandwiched between the steel plate with the predetermined plasticity and the steel plate with the predetermined strength. In this structure, the transformer arc fault buffer energy absorption device is located at the manhole cover. In this structure, both buffer plates 1 and the honeycomb aluminum plate or foam aluminum plate sandwiched between the two buffer plates 1 are circular plates.

[0038] In practice, the preset plasticity and preset strength can be determined according to the actual situation, and this embodiment does not impose any restrictions on them.

[0039] See Figure 3 The transformer arc fault buffer energy absorption device also includes a reinforcing rib plate 6 and an elastic element 7. The reinforcing rib plate 6 is positioned on the outside of a steel plate with a preset strength, with a honeycomb aluminum plate or foam aluminum plate sandwiched between the reinforcing rib plate 6 and the steel plate with a preset plasticity. The elastic element 7 is positioned between the reinforcing rib plate 6 and the bolt head; this elastic element 7 can be a spring. Thus, by using the reinforcing rib plate 6, the energy absorption effect is achieved, reducing the shear bending stress on the bolt 4 and lowering the risk of the cover plate flying off due to bolt 4 breakage or bolt hole tearing. After the honeycomb aluminum plate or foam aluminum plate collapses and absorbs energy, the elastic element 7 can reset and seal the transformer arc fault buffer energy absorption device and flange 3, preventing oil leakage.

[0040] Specifically, when there are multiple bolt caps at the handhole cover, there are also multiple elastic elements 7. The number of elastic elements 7 is the same as the number of bolt caps, and each elastic element 7 corresponds to each bolt cap. Each elastic element 7 is located between the reinforcing rib plate 6 and the corresponding bolt cap.

[0041] See Figure 4 When the transformer is operating normally, the transformer arc fault buffer energy absorption device has sufficient basic strength to meet the tightening requirements of bolt 4, and it does not deform under the preload of bolt 4 and the vibration of the transformer during operation. In the event of a fault, the increased hydraulic pressure in the tank pushes the upper flange upwards. When the pressure is sufficiently high, the transformer arc fault buffer energy absorption device will undergo compression deformation, absorbing the fault and releasing the impact energy outwards, forming a circumferential discharge channel for insulating oil at the paired flanges. After a fault, the pressure inside the tank decreases, and the structure resets under its own weight, sealing the paired flanges. This reduces the risk of fire caused by the arc or high-temperature oil-gas mixture coming into contact with oxygen inside the tank, and prevents oil leakage.

[0042] The buffer structure 2 can maximize energy absorption efficiency by optimizing parameter ratios while ensuring stable transmission of bolt preload. Specifically, when the buffer structure 2 is a honeycomb aluminum panel, the parameters of the honeycomb aluminum panel are cell size, cell wall thickness, and the thickness of the honeycomb aluminum panel. Figure 1 and Figure 2 In the structure shown, the thickness of the honeycomb aluminum panel is the distance between two aluminum panels; Figure 3 In the structure shown, the thickness of the honeycomb aluminum panel is the distance between a steel plate with a predetermined plasticity and a steel plate with a predetermined strength. When the buffer structure 2 is a foamed aluminum panel, the parameters of the foamed aluminum panel are its porosity and its thickness. Figure 1 and Figure 2 In the structure shown, the thickness of the aluminum foam board is equal to the distance between the two aluminum boards; Figure 3 In the structure shown, the thickness of the aluminum foam board is the distance between a steel plate with a preset plasticity and a steel plate with a preset strength.

[0043] By changing the height of the honeycomb aluminum panel and the side length of the cell (see...) Figure 5 (a represents the cell edge length) and cell wall thickness (see [reference]). Figure 5 (The cell wall thickness at point b) can achieve a good buffering and energy absorption effect.

[0044] A simulation model was constructed based on the operating load. By adjusting the cell geometry (such as the side length and wall thickness of a regular hexagonal cell) and the buffer layer thickness gradient (e.g., using 5mm as the reference for adjusting the step size), and combining finite element simulation analysis with stress distribution cloud maps and energy dissipation curves under different combinations, the optimal structural scheme that combines preload and specific energy absorption value was finally selected. This effectively balances mechanical connection strength and impact absorption performance. In the event of a failure, the flange bolt holes and bolts are less likely to tear, and it can withstand higher-intensity arc faults.

[0045] When a large arc fault occurs inside the transformer, the honeycomb aluminum panel absorbs energy through crushing, preventing bolt tearing and thus preventing the cover plate from flying off, ensuring the safety and reliability of components such as the oil tank or riser. The porous internal structure of the honeycomb aluminum panel makes it lightweight, with high specific strength and specific stiffness, effectively reducing structural weight while maintaining good load-bearing capacity. Upon impact, the honeycomb walls of the aluminum panel undergo plastic deformation, absorbing a large amount of energy and acting as a buffer.

[0046] The transformer arc fault buffer energy absorption device adopts a modular layout outside the oil tank. Its installation location completely avoids the electric field distribution area inside the oil tank, requiring no modification to the original insulation structure design and process treatment. From an engineering implementation perspective, the device is highly compatible with the existing oil tank assembly system, and can be quickly installed directly through standard interfaces while maintaining the stability of insulation performance.

[0047] In summary, in this embodiment, both buffer plates 1 and buffer structure 2 are placed at the connection between the flange 3 and bolt 4 of the transformer tank. This allows for the absorption of fault energy and sudden stress, reducing the tensile and shear stress on the bolt 4. Furthermore, it does not alter the original internal structure of the transformer tank, reducing the impact stress at the location of the bolt 4 on the flange 3, preventing bolt 4 breakage or structural failure. It eliminates the need to consider the impact on the electric field distribution, effectively ensuring the normal operation of the transformer. This solves the problem in the prior art where placing buffer energy-absorbing materials inside the tank easily affects the normal operation of the transformer. The device can withstand the mechanical strength test of the transformer tank and does not undergo plastic deformation under normal operating conditions, thus meeting the mechanical strength and sealing requirements of the transformer tank.

[0048] Transformer oil tank example:

[0049] This embodiment also proposes a transformer oil tank, which includes a tank body and multiple transformer arc fault buffering and energy-absorbing devices as described above. Each transformer arc fault buffering and energy-absorbing device is located outside the tank body, and is positioned at the connection point between the flange 3 and bolt 4 of the tank body. Specifically, the connection point between the flange 3 and bolt 4 of the tank body can be the flange and bolt connection point at the riser seat, the bushing flange and bolt connection point, the flange and bolt connection point at the manhole cover plate, etc.

[0050] The specific implementation process of the transformer arc fault buffer energy absorption device can be found in the above description, and will not be repeated here in this embodiment.

[0051] Since the transformer arc fault buffer energy absorption device has the above-mentioned effects, the transformer oil tank with the transformer arc fault buffer energy absorption device also has the corresponding technical effects.

[0052] Example of parameter determination method:

[0053] This embodiment also proposes a method for determining the parameters of the buffer structure in the above-mentioned transformer arc fault buffer energy absorption device. (See [link to relevant documentation]) Figure 9 The method for determining this parameter includes the following steps:

[0054] Stress determination step S1: Determine the stress borne by the transformer arc fault buffer energy absorption device based on the explosion energy of the transformer oil tank, the buffer plate in the transformer arc fault buffer energy absorption device, and the main stress-bearing area at the transformer oil tank flange.

[0055] Specifically, when the transformer arc fault buffer energy absorption device is installed at the connecting flange, the main force-bearing area between the buffer plate 1 and the transformer tank flange 3 is the sum of the contact areas between each bolt cap at the connecting flange and the contacting buffer plate 1. Specifically, the connecting flange can be a riser flange or a bushing flange. This situation is suitable for... Figure 2 The structure consists of two aluminum buffer plates 1, with a honeycomb aluminum plate or foam aluminum plate forming the buffer structure 2 between them. Due to the rigidity of the buffer plates 1, the force is distributed to other parts of the buffer structure 2. After deformation, the main force is concentrated on the contact area between the bolt heads and the buffer plates 1. Furthermore, there are multiple bolts at the connecting flange, evenly spaced along the circumference of the transformer tank. Therefore, the main stress-bearing area between the buffer plates 1 and the transformer tank flange 3 is the sum of the contact areas between all the bolt heads and the contacting buffer plates 1.

[0056] When the transformer arc fault buffer energy absorption device is installed at the manhole cover, the main force-bearing area between the buffer plate 1 and the transformer tank flange 3 is equal to the sum of the contact areas between each bolt head at the manhole cover and the contacting buffer plate 1, plus the area of ​​the buffer plate 1 inside the flange 3 at the manhole cover. This situation is suitable for... Figure 3 The structure includes a buffer plate 1 with a predetermined plasticity that contacts the flange 3 at the handhole cover, and another buffer plate 1 with a predetermined strength. A reinforcing rib 6 is provided on the outside of the steel plate with predetermined strength, and an elastic element 7 is provided between the reinforcing rib 6 and the bolt head. The buffer structure 2 between the steel plate with predetermined plasticity and the steel plate with predetermined strength is a honeycomb aluminum plate or a foamed aluminum plate.

[0057] There are multiple bolts at the manhole cover, evenly spaced circumferentially. Therefore, the sum of the contact areas between each bolt head and the contacting buffer plate 1 is equal to the sum of the contact areas between all bolt heads and the contacting buffer plate 1. Furthermore, since the flange 3 at the manhole cover is annular and the buffer plate 1 is circular, the portion of the buffer plate 1 in contact with the flange 3 at the center of the flange 3 constitutes the pressure zone inside the oil tank. Therefore, the area of ​​the buffer plate 1 inside the flange 3 at the manhole cover is equal to the area of ​​the buffer plate 1 at the center of the flange 3.

[0058] Main bearing area = the sum of the contact areas between each bolt head at the handhole cover and the steel plate with preset rigidity + the area of ​​the steel plate with preset plasticity placed inside the flange 3 at the handhole cover.

[0059] When a reinforcing rib 6 is provided on the outside of a steel plate with a preset strength, the sum of the contact areas between each bolt head at the handhole cover and the steel plate with a preset stiffness is the sum of the contact areas between each bolt head at the handhole cover and the reinforcing rib 6. Therefore, the main stress area = the sum of the contact areas between each bolt head at the handhole cover and the reinforcing rib 6 + the area of ​​the steel plate with preset plasticity placed inside the flange 3 at the handhole cover.

[0060] The stress borne by the transformer arc fault buffer energy absorption device is determined based on the explosion energy and stress area of ​​the transformer oil tank.

[0061] In step S2, adjust the parameters of the buffer structure according to the stress borne by the transformer arc fault buffer energy absorption device, and obtain multiple sets of parameter data.

[0062] Specifically, based on the stress determined in stress determination step S1, the parameters of the buffer structure are continuously adjusted, and the adjusted parameters of the multiple buffer structures are combined into multiple sets of parameter data.

[0063] The buffer structure 2 is a honeycomb aluminum plate or a foam aluminum plate.

[0064] When the buffer structure 2 is a honeycomb aluminum panel, the parameters of the honeycomb aluminum panel are cell size, cell wall thickness, and the thickness of the honeycomb aluminum panel. The thickness of the honeycomb aluminum panel is the distance between the two buffer plates 1. Figure 1 and Figure 2 In the structure shown, the thickness of the honeycomb aluminum panel is the distance between two aluminum panels; Figure 3 In the structure shown, the thickness of the honeycomb aluminum panel is the distance between a steel plate with a preset plasticity and a steel plate with a preset strength.

[0065] When the buffer structure 2 is an aluminum foam board, the parameters of the aluminum foam board are its porosity and thickness. The thickness of the aluminum foam board is the distance between the two buffer boards 1. Figure 1 and Figure 2 In the structure shown, the thickness of the aluminum foam board is equal to the distance between the two aluminum boards; Figure 3 In the structure shown, the thickness of the aluminum foam board is the distance between a steel plate with a preset plasticity and a steel plate with a preset strength.

[0066] More specifically, a simulation calculation model is constructed based on the working load. By adjusting the geometric dimensions of the cell (such as the side length and cell wall thickness of a regular hexagonal cell) and the thickness gradient of the honeycomb aluminum plate or foam aluminum plate (such as using 5mm as the reference for adjusting the step size), multiple sets of buffer structure parameters are obtained. The parameters of each set of buffer structures form multiple sets of parameter data.

[0067] In step S3, finite element simulation analysis is performed on each set of parameter data to determine the stress distribution cloud map and energy dissipation curve.

[0068] Specifically, finite element simulation analysis was performed on each set of parameter data to obtain stress distribution cloud maps and energy dissipation curves under different combinations.

[0069] In screening step S4, the parameters of the buffer structure are determined based on the stress distribution cloud map, energy dissipation curve, and installation conditions of the transformer tank.

[0070] Specifically, based on the stress distribution cloud map, energy dissipation curve, and installation conditions of the transformer tank, the parameters of the buffer structure that combine the optimal solutions for preload and specific energy absorption are selected, and this parameter data serves as the final data for the buffer structure.

[0071] The specific implementation process of the transformer arc fault buffer energy absorption device can be found in the above description, and will not be repeated here in this embodiment.

[0072] As can be seen, in this embodiment, the stress borne by the transformer arc fault buffer energy absorption device is determined based on the explosion energy of the transformer tank and the main stress-bearing area of ​​the buffer plate and the transformer tank flange in the transformer arc fault buffer energy absorption device. Then, the parameters of the buffer structure are adjusted, and multiple sets of parameter data are obtained. Finite element simulation analysis is then performed on each set of parameter data to determine the stress distribution cloud map and energy dissipation curve. Combined with the installation conditions of the transformer tank, the parameters of the buffer structure are determined. This allows for accurate determination of the buffer structure parameters, ensuring that the transformer arc fault buffer energy absorption device has a good buffer energy absorption effect, effectively absorbing fault energy and sudden stress, reducing the tensile and shear stress borne by the bolts, and without altering the original internal structure of the transformer tank. It reduces the impact stress at the bolt location on the flange, preventing bolt breakage or structural failure, and eliminates the need to consider the impact on the electric field distribution, effectively ensuring the normal operation of the transformer.

[0073] It should be noted that the transformer arc fault buffer energy absorption device, transformer oil tank and parameter determination method in this invention are based on the same principle, and related parts can be referred to each other.

[0074] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0075] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A transformer arc fault buffer and energy absorption device, characterized in that, include: Two buffer plates (1) and a buffer structure (2); wherein, The buffer structure (2) is sandwiched between the two buffer plates (1), one of the buffer plates (1) is used to contact the flange (3) of the transformer oil tank, and the bolt (4) at the flange (3) of the transformer oil tank passes through the two buffer plates (1), the buffer structure (2) and the flange (3) of the transformer oil tank and is screwed to the nut (5); wherein, the flange (3) of the transformer oil tank is the flange of the riser seat or the flange at the manhole cover plate; When the flange (3) of the transformer tank is the flange at the manhole cover, the buffer plate (1) in contact with the flange (3) of the transformer tank is a steel plate with preset plasticity, and the other buffer plate (1) is a steel plate with preset strength; the transformer arc fault buffer energy absorption device also includes: a reinforcing rib plate (6) and an elastic element (7); wherein, the reinforcing rib plate (6) is disposed on the outside of the steel plate with preset strength; the elastic element (7) is disposed between the reinforcing rib plate (6) and the bolt head; The buffer structure (2) is a honeycomb aluminum plate or a foam aluminum plate; The parameters of the buffer structure (2) are determined by the following steps: The stress determination step involves determining the stress borne by the transformer arc fault buffer energy absorption device based on the explosion energy of the transformer oil tank and the main stress-bearing area of ​​the buffer plate in the transformer arc fault buffer energy absorption device and the flange of the transformer oil tank. The adjustment steps involve adjusting the parameters of the buffer structure based on the stress borne by the transformer arc fault buffer energy absorption device, and obtaining multiple sets of parameter data. The analysis steps involve performing finite element simulation analysis on each set of parameter data to determine the stress distribution cloud map and energy dissipation curve; The screening step involves determining the parameters of the buffer structure based on the stress distribution cloud map, the energy dissipation curve, and the installation conditions of the transformer tank. In the stress determination step When the transformer arc fault buffer energy absorption device is installed at the riser flange, the main force-bearing area of ​​the buffer plate and the flange of the transformer oil tank is the sum of the contact areas between each bolt cap at the riser flange and the buffer plate in contact with it. When the transformer arc fault buffer energy absorption device is installed at the manhole cover, the main force-bearing area of ​​the buffer plate and the flange of the transformer oil tank is equal to the sum of the contact areas between each bolt head at the manhole cover and the contacting buffer plate, plus the area of ​​the buffer plate in contact with the flange at the manhole cover placed inside the flange at the manhole cover. In the adjustment steps When the buffer structure is a honeycomb aluminum plate, the parameters of the honeycomb aluminum plate are cell size, cell wall thickness and honeycomb aluminum plate thickness; When the buffer structure is a foamed aluminum plate, the parameters of the foamed aluminum plate are porosity and thickness.

2. A transformer oil tank, characterized in that, include: The enclosure and multiple transformer arc fault buffer energy absorption devices as described in claim 1; wherein, Each of the transformer arc fault buffer energy absorption devices is located outside the enclosure, and each of the transformer arc fault buffer energy absorption devices is located at the connection between the flange (3) and the bolt (4) of the enclosure.

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