Oil-immersed transformer bushing anti-explosion design method and system

Abstract

The invention discloses an oil-immersed transformer bushing anti-explosion design method and system, and relates to the technical field of transformer safety, and the method comprises the steps: simplifying and building an oil-immersed bushing fluid-structure interaction finite element model; the gas excitation position and flow setting in the casing are determined, the response condition of the specified casing system under the design fault resisting working condition is simulated and analyzed, and the safety of the structure is judged; and the anti-explosion safety of the oil-immersed casing pipe structure under the design fault resisting working condition is completed. According to the method, the oil-immersed casing anti-explosion design process is provided, and the specified limit bearing working condition is defined so that economy and safety can be considered; and a numerical method for accurately simulating the arc fault of the oil-immersed sleeve considering the characteristics of the oil space in the sleeve is provided to provide data support for anti-explosion design.

Description

Technical Field

[0001] The invention relates to the technical field of transformer safety, and in particular to an explosion-proof design method and system for oil-immersed transformer bushings. Background Art

[0002] At present, the explosion of power transformers caused by internal low-impedance arc faults is a key issue of concern to the entire power industry. The probability of fire caused by transformer arc fault explosion is about 0.1% per year, which will cause catastrophic accidents such as oil leakage, fire, and even fire and explosion chain disasters, posing a threat to personal safety, economic losses and potential environmental problems. Measures such as oil drainage and nitrogen injection equipment and large plastic deformation oil tanks have been verified to be effective in reducing risks when arcs occur in transformers. However, if high-energy arcs occur in other less-oil equipment such as oil-immersed bushings, it gradually becomes one of the main causes of transformer fires. Oil-immersed bushings, especially oil-immersed paper bushings, are key components of power transformers, and their operating performance is directly related to the operating safety of the transformer and even the entire power grid. Therefore, research on the explosion resistance of oil-immersed bushings is particularly important.

[0003] The existing numerical simulation methods for arc faults in oil-immersed bushings are consistent with those for arc faults in oil-immersed transformers, and are mainly divided into two categories: one is to simulate the load by releasing energy at one time, and the other is to simulate the load by considering the entire process of energy release. Among the methods of releasing energy at one time, the typical representative is the TNT method. The TNT equivalent method converts the energy released by the arc into TNT equivalent based on the principle of energy conservation, and uses the explosive simulation technology in the LS-DYNA software to analyze the oil pressure distribution law and the box response characteristics inside the transformer during the arc fault. Considering the entire process of energy release to simulate the load, some scholars have considered the entire process of energy release to simulate the load and proposed a load application method that considers the relationship between arc power and bubble pressure. They constructed a multi-field coupling model of an oil-immersed transformer and simulated it using the COMSOL Multiphysics software platform. By establishing the relationship between arc power and the pressure difference between the two-phase interface, this method can apply a more accurate load, and at the same time provide key data such as winding transient leakage magnetic flux, dynamic electromotive force, box deformation, and oil pressure. However, the oil space inside the oil-immersed bushing is small and the oil thickness is limited, which greatly affects the behavior of the gas. Existing simulation methods for transformers do not take this into account. Summary of the invention

[0004] In view of the problems existing in the existing explosion-proof design method and system for oil-immersed transformer bushing, the present invention is proposed.

[0005] Therefore, the present invention aims at the problem that the internal oil space of the oil-immersed bushing is small and the oil thickness is limited, which greatly affects the behavior of the gas. The existing simulation methods for transformers do not take this into consideration. The present invention solves this problem by adopting an explosion-proof design method for oil-immersed transformer bushing.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides an explosion-proof design method for oil-immersed transformer bushings, which includes determining the oil-immersed bushing structure and material selection to be analyzed, designing the layout of the fault resistance and pressure release device, simplifying and establishing a fluid-solid coupling finite element model of the oil-immersed bushing;

[0008] According to the determined design fault resistance working conditions and the characteristics of the oil space inside the casing, determine the gas excitation position and flow setting inside the casing, simulate and analyze the response of the specified casing pipe pattern under the design fault resistance working conditions, and judge the safety of the structure;

[0009] According to the response results, the hollow insulator, flange, flange glue and pressure relief device are optimized to complete the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions.

[0010] As a preferred solution of the explosion-proof design method of oil-immersed transformer bushing of the present invention, the structure and material selection of the oil-immersed bushing to be analyzed include determining the structure and working conditions for analysis, the main components of the oil-immersed bushing include hollow insulators, mounting flanges, conductive tubes, capacitor cores, oil pillows and insulating oil, the pressure release device is arranged at the middle mounting flange and the end flange, the preset arc fault conditions to be resisted are 1MJ energy and 60ms duration, and the position is 30cm away from the oil end base.

[0011] As a preferred solution of the explosion-proof design method of the oil-immersed transformer bushing of the present invention, wherein: simplifying and establishing the fluid-solid coupling finite element model of the oil-immersed bushing includes simplifying the finite element model, the simplified finite element model includes two important components that need to be analyzed for response, namely, the hollow insulator and the mounting flange, the capacitor core, the component that affects the propagation of pressure waves inside the box, the insulating oil and the air, the two fluids for the propagation of pressure waves, the hollow insulator, the mounting flange and the capacitor core are all established using Lagrange shell units, the fluid unit is established using ALE units, the flange structure is steel or aluminum alloy, a double-fold line material model is used, the strain effect of steel is considered through the Johnson-Cook model or the Cowper-Symonds model, the hollow insulator is a glass fiber reinforced plastic composite material or a high-strength ceramic, the bushing is a glass fiber reinforced plastic composite material, an anisotropic model is used, and the destruction of the material is defined by the Hashin criterion;

[0012] When pressure waves and insulating oil act on the structure, there will be complex interactions of force and deformation between the structure and the fluid. The fluid-solid coupling between the insulating oil and the bushing structure is considered to ensure the accuracy of the calculation results. The fluid-solid coupling is set using the keyword *CONSTRAINED_LAGRANGE_IN_SOLID.

[0013] As a preferred solution of the explosion-proof design method of the oil-immersed transformer bushing of the present invention, wherein: determining the gas excitation position and flow setting in the bushing includes determining the gas excitation position and flow setting in the bushing according to the determined fault condition, the thickness of the insulating oil inside the oil-immersed bushing is relatively small, and the gas form of the insulating oil gas generated by the arc fault is limited by space, a linear layout method close to the actual arc length is selected, and the gas excitation position is evenly arranged at the fault position according to the arc length, and the boundary flow velocity is calculated as follows:

[0014]

[0015] Among them, m represents flow rate, E represents parameter, A represents gas parameter, t represents time, and ρ represents density.

[0016] As a preferred solution of the explosion-proof design method for oil-immersed transformer bushing of the present invention, judging the safety of the structure includes analyzing the bushing response to judge whether the structure is safe or not, the preset calculation time is greater than the actual fault time so that the response can be sufficiently developed, and the safety of the structure is judged by the post-processing unit deletion situation.

[0017] As a preferred solution of the explosion-proof design method of oil-immersed transformer bushing of the present invention, wherein: optimizing the hollow insulator, flange, flange glue and pressure release device according to the response result includes optimizing the explosion-proof of the bushing structure;

[0018] If the structure is damaged, the thickness, connection method and shape of the structure can be optimized according to the damage location, damage mode, stress and strain conditions.

[0019] As a preferred solution of the explosion-proof design method of the oil-immersed transformer bushing of the present invention, the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions includes extracting the pressure load time history at the flange, verifying the flange glue separately with this time history, monitoring the connection safety of the flange glue, evenly arranging the pressure time history measurement points in the insulating oil, comparing the pressure conditions before and after the pressure release device is triggered to judge the pressure relief effect of the device, and then judging the safety of the structure after optimization, so as to achieve the balance between the economy and safety of the design.

[0020] In a second aspect, an embodiment of the present invention provides an explosion-proof design system for oil-immersed transformer bushings, which includes: an analysis module, which determines the oil-immersed bushing structure and material selection to be analyzed, designs the fault resistance working conditions and the layout of the pressure release device, simplifies and establishes a fluid-solid coupling finite element model of the oil-immersed bushing;

[0021] The judgment module determines the gas excitation position and flow setting in the casing according to the determined design fault resistance working conditions and the characteristics of the oil space inside the casing, simulates and analyzes the response of the prescribed casing pipe pattern under the design fault resistance working conditions, and judges the safety of the structure;

[0022] The design module optimizes the hollow insulator, flange, flange adhesive and pressure relief device according to the response results to complete the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions.

[0023] In a third aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, any step of the above-mentioned oil-immersed transformer bushing explosion-proof design method is implemented.

[0024] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned method for explosion-proof design of oil-immersed transformer bushing is implemented.

[0025] The beneficial effects of the present invention are as follows: compared with the prior art, the advantages of the present invention are summarized as follows: a process for explosion-proof design of oil-immersed bushing is proposed, and the specified limit bearing conditions are clearly specified to take into account both economy and safety; a numerical method for accurately simulating arc faults of oil-immersed bushings taking into account the characteristics of the oil space inside the bushing is proposed to provide data support for explosion-proof design. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0027] Figure 1 A flow chart of an explosion-proof design method and system for oil-immersed transformer bushing provided in one embodiment of the present invention.

[0028] Figure 2 A schematic diagram of a finite element model of an oil-immersed transformer bushing explosion-proof design method and system provided in accordance with an embodiment of the present invention.

[0029] Figure 3 A schematic diagram of changes in a stress field cloud diagram of an oil-immersed transformer bushing finite element model of an explosion-proof design method and system for an oil-immersed transformer bushing provided by an embodiment of the present invention.

[0030] Figure 4 A time history diagram of average pressure on the end flange of an oil-immersed transformer bushing finite element model according to an explosion-proof design method and system for an oil-immersed transformer bushing provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0034] The present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0035] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Example 1

[0038] Reference Figure 1 to Figure 4 , which is the first embodiment of the present invention, provides an explosion-proof design method for oil-immersed transformer bushing, comprising:

[0039] S1: Determine the oil-immersed casing structure and material selection that need to be analyzed, design the layout of the fault resistance and pressure relief device, simplify and establish the fluid-solid coupling finite element model of the oil-immersed casing.

[0040] Among them, determining the oil-immersed bushing structure and material selection that need to be analyzed includes determining the structure and working conditions for analysis. The main components of the oil-immersed bushing include hollow insulators, mounting flanges, conductive tubes, capacitor cores, oil pillows and insulating oil. The pressure release device is arranged at the middle mounting flange and the end flange. The preset arc fault conditions are 1MJ energy and 60ms duration, and the position is 30cm away from the oil end base.

[0041] S1.1: Simplify and establish the fluid-solid coupling finite element model of oil-immersed bushing, including the simplification of the finite element model. The simplified finite element model includes two important components that need to be analyzed for response, namely, the hollow insulator and the mounting flange. The capacitor core is a component that affects the propagation of pressure waves inside the box. The insulating oil and air are two fluids for the propagation of pressure waves. The hollow insulator, the mounting flange and the capacitor core are all established using Lagrange shell units, and the fluid unit is established using ALE units. The flange structure is steel or aluminum alloy, and a double-fold line material model is used. The strain effect of steel is considered through the Johnson-Cook model or the Cowper-Symonds model. The hollow insulator is a glass fiber reinforced plastic composite material or high-strength ceramic. The bushing is a glass fiber reinforced plastic composite material. An anisotropic model is used and the material failure is defined through the Hashin criterion.

[0042] When pressure waves and insulating oil act on the structure, there will be complex interactions of force and deformation between the structure and the fluid. The fluid-solid coupling between the insulating oil and the bushing structure is considered to ensure the accuracy of the calculation results. The fluid-solid coupling is set using the keyword *CONSTRAINED_LAGRANGE_IN_SOLID.

[0043] S2: According to the determined design fault resistance conditions and the characteristics of the oil space inside the casing, determine the gas excitation position and flow setting inside the casing, simulate and analyze the response of the specified casing control formula under the design fault resistance conditions, and judge the safety of the structure.

[0044] Among them, determining the gas excitation position and flow setting in the bushing includes determining the gas excitation position and flow setting in the bushing according to the determined fault conditions. The thickness of the insulating oil inside the oil-immersed bushing is relatively small. The gas form of the insulating oil generated by the arc fault is limited by space. A linear layout method close to the actual arc length is selected to evenly arrange the gas excitation position at the fault position according to the arc length. The boundary flow velocity is calculated as follows:

[0045]

[0046] Among them, m represents flow rate, E represents parameter, A represents gas parameter, t represents time, and ρ represents density.

[0047] S2.1: Determining the safety of the structure includes analyzing the casing response to determine the safety of the structure. The preset calculation time is greater than the actual failure time so that the response can be sufficiently developed. The safety of the structure is determined by the post-processing unit deletion.

[0048] S3: Based on the response results, the hollow insulator, flange, flange glue and pressure relief device are optimized to complete the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions.

[0049] Among them, completing the explosion-proof safety of the oil-immersed bushing structure under the design of fault resistance conditions includes extracting the pressure load time series at the flange, verifying the flange glue separately with this time series, monitoring the connection safety of the flange glue, evenly arranging pressure time series measurement points in the insulating oil, comparing the pressure conditions before and after the pressure release device is triggered to determine the pressure relief effect of the device, and then judging the safety of the structure after optimization, so as to achieve a design that takes into account both the economy and safety.

[0050] In a preferred embodiment, an explosion-proof design system for oil-immersed transformer bushings includes an analysis module, which determines the oil-immersed bushing structure and material selection to be analyzed, designs the fault resistance conditions and pressure relief device layout, simplifies and establishes a fluid-solid coupling finite element model of the oil-immersed bushing;

[0051] The judgment module determines the gas excitation position and flow setting in the casing according to the determined design fault resistance working conditions and the characteristics of the oil space inside the casing, simulates and analyzes the response of the prescribed casing pipe pattern under the design fault resistance working conditions, and judges the safety of the structure;

[0052] The design module optimizes the hollow insulator, flange, flange adhesive and pressure relief device according to the response results to complete the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions.

[0053] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0054] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0055] In summary, compared with the prior art, the advantages of the present invention are that it proposes a process for explosion-proof design of oil-immersed bushings, clarifies the specified limit bearing conditions to balance economy and safety; and proposes a numerical method for accurately simulating arc faults of oil-immersed bushings that takes into account the characteristics of the oil space inside the bushing to provide data support for explosion-proof design.

[0056] Example 2

[0057] Reference Figure 1 to Figure 4 , which is the second embodiment of the present invention, and this embodiment provides an explosion-proof design method and system for oil-immersed transformer bushing. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through simulation experiments.

[0058] In the experimental process of the technology of the present invention, the oil-immersed bushing structure and material selection that need to be analyzed are first determined. The experimental object is a typical oil-immersed bushing, the main components of which include hollow insulators, mounting flanges, conductive tubes, capacitor cores, oil pillows and insulating oil. In order to resist arc fault conditions, an arc fault with an energy of 1 megajoule and a duration of 60 milliseconds is preset. The fault location is set at 30 cm from the oil end base, and the pressure release device is set at the middle mounting flange and the end flange.

[0059] The fluid-solid coupling finite element model of the oil-immersed bushing was simplified and established. In the model, the hollow insulator and the mounting flange were established using Lagrange shell elements, the fluid element was established using ALE elements, the flange structure was made of steel, the material model used was a double-fold line material model, and the strain effect of the steel was considered using the Johnson-Cook model. The hollow insulator was made of glass fiber reinforced plastic composite material, the material model was an anisotropic model, and the material failure was defined by the Hashin criterion.

[0060] The gas excitation position and flow setting in the bushing are determined according to the preset fault conditions. Since the insulating oil thickness inside the oil-immersed bushing is relatively small, the gas form of the insulating oil gas produced by the arc fault is limited by space. A linear layout method close to the actual arc length is adopted. The gas excitation positions are evenly arranged at the fault position according to the arc length, and the boundary flow velocity of the gas excitation is calculated by simulation software.

[0061] Finite element software was used for simulation analysis, with a preset calculation time of 100 milliseconds to ensure that the response was fully developed. The safety of the structure was judged by the post-processing unit deletion. The results showed that some hollow insulators and flange structures were locally damaged under the action of the arc fault, with a maximum stress of 200 MPa and a maximum displacement of 5 mm.

[0062] According to the response results, the hollow insulators, flanges, flange glue and pressure release devices were optimized. The optimization measures included increasing the wall thickness of the hollow insulators, improving the flange connection method, enhancing the bonding strength of the flange glue, and adjusting the position and number of the pressure release devices. After optimization, finite element analysis was carried out again. The results showed that the maximum stress of the structure was reduced to 150 MPa, the maximum displacement was reduced to 3 mm, and no obvious damage occurred.

[0063] The pressure load time history at the flange was extracted, the flange adhesive was individually verified, and the connection safety of the flange adhesive was monitored. The pressure measurement points were evenly arranged in the insulating oil, and the pressure conditions before and after the pressure release device was triggered were compared to determine the pressure relief effect of the device. The optimized design achieved a good balance between economy and safety, and completed the explosion-proof safety verification of the oil-immersed bushing structure under the design to resist fault conditions. The experimental data of the present invention are shown in Table 1 below:

[0064] Table 1 Experimental data table of the present invention

[0065] Data Types Numeric Arc fault energy 1MJ Arc fault duration 60ms Fault location distance from oil end base 30cm Flange material Steel Hollow Insulator Materials Fiberglass composite materials Preset calculation time 100ms Maximum stress (initial design) 200MPa Maximum displacement (initial design) 5mm Increase in wall thickness of hollow insulator - Improvement of flange connection - Flange adhesive bonding strength is enhanced - Adjustment of the location and quantity of pressure relief devices - Maximum stress (after optimization) 150MPa Maximum displacement (after optimization) 3mm

[0066] Table 1 clearly shows the key data points in the experiment, which helps to understand the experimental process and its results. The structural response data before and after optimization are particularly emphasized, highlighting the advantages of the technical solution of the present invention. The comparison between the present invention and the prior art is shown in Table 2 below:

[0067] Table 2 Comparison between the present invention and the prior art

[0068]

[0069] Table 2 clearly demonstrates the advantages of the technical solution of the present invention in many aspects, highlighting its significant improvements in arc fault resistance, maximum stress and displacement control, pressure release effect, flange connection safety, structural optimization, calculation accuracy, response time, economy and material selection.

[0070] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for explosion-proof design of oil-immersed transformer bushing, characterized in that: include, Determine the oil-immersed casing structure and material selection that need to be analyzed, design the fault resistance and pressure relief device layout, simplify and establish the fluid-solid coupling finite element model of the oil-immersed casing; According to the determined design fault resistance working conditions and the characteristics of the oil space inside the casing, determine the gas excitation position and flow setting inside the casing, simulate and analyze the response of the specified casing pipe pattern under the design fault resistance working conditions, and judge the safety of the structure; According to the response results, the hollow insulator, flange, flange glue and pressure relief device are optimized to complete the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions.

2. The explosion-proof design method for oil-immersed transformer bushing according to claim 1, characterized in that: Determining the oil-immersed bushing structure and material selection that need to be analyzed includes determining the structure and operating conditions for analysis. The main components of the oil-immersed bushing include hollow insulators, mounting flanges, conductive tubes, capacitor cores, oil pillows and insulating oil. The pressure relief device is set at the middle mounting flange and the end flange. The preset arc fault conditions are 1MJ energy and 60ms duration, and the position is 30cm away from the oil end base.

3. The explosion-proof design method for oil-immersed transformer bushing according to claim 2, characterized in that: Simplifying and establishing the fluid-solid coupling finite element model of the oil-immersed bushing includes simplifying the finite element model. The simplified finite element model includes two important components that need to be analyzed for response, namely, the hollow insulator and the mounting flange. The capacitor core is a component that affects the propagation of pressure waves inside the box. The insulating oil and air are two fluids for the propagation of pressure waves. The hollow insulator, the mounting flange and the capacitor core are all established using Lagrange shell units, and the fluid unit is established using ALE units. The flange structure is steel or aluminum alloy, and a double-fold line material model is used. The strain effect of steel is considered through the Johnson-Cook model or the Cowper-Symonds model. The hollow insulator is a glass fiber reinforced plastic composite material or high-strength ceramic. The bushing is a glass fiber reinforced plastic composite material. An anisotropic model is used and the destruction of the material is defined through the Hashin criterion. When pressure waves and insulating oil act on the structure, there will be complex interactions of force and deformation between the structure and the fluid. The fluid-solid coupling between the insulating oil and the bushing structure is considered to ensure the accuracy of the calculation results. The fluid-solid coupling is set using the keyword *CONSTRAINED_LAGRANGE_IN_SOLID.

4. The explosion-proof design method for oil-immersed transformer bushing according to claim 3, characterized in that: Determining the gas excitation position and flow setting in the bushing includes determining the gas excitation position and flow setting in the bushing according to the determined fault conditions. The thickness of the insulating oil inside the oil-immersed bushing is relatively small. The gas form of the insulating oil generated by the arc fault is limited by space. A linear layout method close to the actual arc length is selected to evenly arrange the gas excitation position at the fault position according to the arc length. The boundary flow velocity is calculated as follows: Among them, m represents flow rate, E represents parameter, A represents gas parameter, t represents time, and ρ represents density.

5. The explosion-proof design method for oil-immersed transformer bushing according to claim 4, characterized in that: Judging the safety of the structure includes analyzing the casing response to judge the safety of the structure. The preset calculation time is greater than the actual failure time so that the response can be sufficiently developed. The safety of the structure is judged by the unit deletion in post-processing.

6. The explosion-proof design method for oil-immersed transformer bushing according to claim 5, characterized in that: According to the response results, the hollow insulator, flange, flange adhesive and pressure relief device are optimized, including explosion-proof optimization of the bushing structure; If the structure is damaged, the thickness, connection method and shape of the structure can be optimized according to the damage location, damage mode, stress and strain conditions.

7. The explosion-proof design method for oil-immersed transformer bushing according to claim 6, characterized in that: The explosion-proof safety of the oil-immersed bushing structure under the design of fault resistance conditions includes extracting the pressure load time series at the flange, verifying the flange rubber separately with this time series, monitoring the connection safety of the flange rubber, evenly arranging the pressure time series measurement points in the insulating oil, comparing the pressure conditions before and after the pressure release device is triggered to determine the pressure relief effect of the device, and then determining the safety of the structure after optimization, so as to achieve a design that takes into account both the economy and safety.

8. An explosion-proof design system for oil-immersed transformer bushings, based on the explosion-proof design method for oil-immersed transformer bushings according to any one of claims 1 to 7, characterized in that: include, The analysis module determines the oil-immersed casing structure and material selection to be analyzed, designs the fault resistance and pressure relief device layout, simplifies and establishes the fluid-solid coupling finite element model of the oil-immersed casing; The judgment module determines the gas excitation position and flow setting in the casing according to the determined design fault resistance working conditions and the characteristics of the oil space inside the casing, simulates and analyzes the response of the prescribed casing pipe pattern under the design fault resistance working conditions, and judges the safety of the structure; The design module optimizes the hollow insulator, flange, flange adhesive and pressure relief device according to the response results to complete the explosion-proof safety of the oil-immersed bushing structure under the design to resist fault conditions.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the explosion-proof design method for oil-immersed transformer bushing according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the explosion-proof design method for oil-immersed transformer bushing according to any one of claims 1 to 7 are implemented.

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