Step-by-step equivalent transformer vibration and noise simulation method

Abstract

This invention discloses a step-by-step equivalent transformer vibration and noise simulation method, comprising: constructing a three-dimensional model of the core based on the magnetostriction simulation and the actual shape of the core; obtaining the deformation simulation results of the core under the influence of magnetostriction effect in the three-dimensional model of the core; constructing a two-dimensional model of the tank, the core, and the winding, obtaining the vibration simulation results of the winding and the sound field distribution simulation results near the winding under the vibration condition; integrating the three-dimensional model of the core and the two-dimensional model of the winding, adding other components to obtain a reconstructed three-dimensional model; and calculating the vibration and noise simulation of the transformer within the reconstructed three-dimensional model. This invention solves the problem of mutual coupling between models of different dimensions, realizes more simulation details, achieves a higher level of simulation accuracy, and enables fast and relatively accurate transformer vibration and noise simulation.

Description

Technical Field

[0001] This invention relates to the field of transformer equipment technology, and in particular to a step-by-step equivalent transformer vibration and noise simulation method. Background Technology

[0002] In related technologies, the finite element method is used to simulate and analyze the entire core and calculate its vibration modes in the study of the inherent vibration characteristics of the core. However, the multi-layer lamination structure of the core makes its mechanical properties exhibit significant anisotropy. Using the overall core model for analysis will result in the natural vibration frequency of the core in the bending direction being much larger than the actual frequency, which cannot well reflect the actual vibration characteristics of the core.

[0003] Furthermore, the vibration characteristics of silicon steel laminations with different numbers of laminations were studied. It was found that the natural frequency of out-of-plane bending vibration of silicon steel sheets does not change with the number of silicon steel sheets. The existing silicon steel sheet lamination model can reflect the inherent vibration characteristics of the core lamination structure, but it has problems such as excessive calculation, difficulty in solving, oversimplification, and large differences between simulation results and reality, and has little reference value for engineering practice.

[0004] Therefore, existing transformer vibration and noise simulation methods suffer from problems such as excessive computational load, difficulty in solving, oversimplification, and significant discrepancies between simulation results and actual results, resulting in limited reference value for practical engineering applications. Summary of the Invention

[0005] The main objective of this invention is to provide a step-by-step equivalent transformer vibration and noise simulation method, which aims to solve the problems of excessive computation, difficulty in solving, oversimplification, large discrepancies between simulation results and actual results in the existing technology, and low reference value for engineering practice.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a step-by-step equivalent transformer vibration and noise simulation method. The transformer is installed inside an oil tank and includes an iron core and windings wound on the iron core. The method includes:

[0008] A three-dimensional model of the iron core is constructed, and the magnetostriction of the iron core under the influence of a magnetic field is calculated to obtain the deformation simulation results of the iron core under the influence of the magnetostriction effect.

[0009] A two-dimensional model of the winding is constructed, and the vibration of the winding is simulated to obtain the vibration simulation results of the winding.

[0010] A reconstructed three-dimensional model of the transformer, including the core, clamps, and oil tank, is established. The deformation simulation results of the core under the influence of magnetostriction are introduced into the sound field simulation. The vibration simulation results of the winding are used as boundary conditions to calculate the vibration noise of the transformer in three dimensions.

[0011] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the step of constructing a three-dimensional model of the iron core and calculating the magnetostriction of the iron core under the influence of a magnetic field to obtain the deformation simulation results of the iron core under the influence of the magnetostriction effect includes:

[0012] Based on the actual shape of the winding and the core, a three-dimensional model of the core is constructed, and the winding is in the form of a cylindrical structure in the three-dimensional model of the core;

[0013] In the three-dimensional model of the iron core, a magnetostrictive model of the iron core is constructed based on the iron core made of soft iron material;

[0014] The magnetic field distribution generated by the winding and the magnetostriction of the iron core under the influence of the magnetic field are calculated to obtain the deformation simulation results of the iron core under the influence of the magnetostriction effect.

[0015] Based on the magnetization curve of the soft iron material, the interpolation data of the magnetization curve and the effective magnetization curve of the magnetostrictive model of the iron core are corrected, and a first attribute condition is set in the magnetostrictive model of the iron core.

[0016] The magnetostrictive model of the iron core is calculated based on the first attribute condition to obtain the deformation simulation results of the iron core under the influence of the magnetostrictive effect.

[0017] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the step of constructing a magnetostrictive model of the iron core based on the soft iron material in the three-dimensional model of the iron core includes:

[0018] A first constraint condition is set in the three-dimensional model constructed based on the core of the soft iron material;

[0019] Based on the first constraint, the iron core in the three-dimensional model is set as the domain to be solved;

[0020] A second constraint is set within the domain to be solved, and the solution result is obtained based on the second constraint.

[0021] The magnetostrictive model of the iron core is obtained based on the solution results.

[0022] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the step of constructing a two-dimensional model of the winding and simulating the vibration of the winding to obtain the vibration simulation results of the winding includes:

[0023] Based on the actual shape of the winding, a two-dimensional model of the winding is constructed;

[0024] Two-dimensional models of the oil tank, iron core, and pad block are constructed in the two-dimensional model, and the vibration of the winding is simulated to obtain the vibration simulation results of the winding.

[0025] Optionally, in the above step-by-step equivalent transformer vibration and noise simulation method, the transformer includes a clamp, which is clamped to the winding;

[0026] The steps of establishing a reconstructed three-dimensional model including the transformer core, clamps, and oil tank, incorporating the deformation simulation results of the core under the influence of magnetostriction into the sound field simulation, and using the vibration simulation results of the windings as boundary conditions to calculate the vibration noise of the transformer in the three-dimensional case include:

[0027] Within the three-dimensional model of the iron core, the winding, the clamp and the oil tank are fully modeled to obtain the three-dimensional model to be integrated;

[0028] Based on the vibration simulation results of the winding, the boundary conditions of the winding are obtained;

[0029] The reconstructed 3D model is obtained by replacing the actual position of the winding with the region in the 3D model to be integrated based on the boundary conditions of the winding.

[0030] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the steps of establishing a reconstructed three-dimensional model including the transformer core, clamps, and tank, introducing the deformation simulation results of the core under the influence of magnetostriction into the sound field simulation, and using the vibration simulation results of the winding as boundary conditions to calculate the transformer vibration and noise in the three-dimensional case include:

[0031] Sound field simulation is performed on the reconstructed 3D model to obtain the sound field simulation results of the reconstructed 3D model;

[0032] By combining the deformation simulation results of the iron core under the influence of magnetostriction and the sound field simulation results, the first sound field simulation quantity is obtained;

[0033] By combining the vibration simulation results of the winding and the sound field simulation results, a second sound field simulation quantity is obtained;

[0034] By combining the first sound field simulation quantity and the second sound field simulation quantity, a complete sound field simulation calculation model is obtained;

[0035] Based on the complete sound field simulation calculation model, the vibration and noise simulation of the transformer is obtained.

[0036] Optionally, in the above step-by-step equivalent transformer vibration and noise simulation method, the clamp is connected to a winding pressure plate;

[0037] The step of combining the vibration simulation results and the sound field simulation results to obtain the second sound field simulation quantity includes:

[0038] Within the two-dimensional model of the winding, the deformation of the winding ends is obtained;

[0039] The deformation at the end of the winding is used as the second constraint condition;

[0040] Based on the second constraint, the second sound field simulation quantity is obtained by simulation in the reconstructed three-dimensional model.

[0041] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the vibration simulation results include sound field distribution simulation results;

[0042] The step of combining the vibration simulation results and the sound field simulation results to obtain the second sound field simulation quantity includes:

[0043] In the two-dimensional model of the winding, the sound field distribution near the winding is obtained by simulation under the condition of winding vibration;

[0044] Based on the sound field distribution near the winding under the condition of winding vibration, the sound field distribution result near the winding is obtained;

[0045] The sound field distribution of the winding is used as the third constraint condition;

[0046] Based on the third constraint, the second sound field simulation quantity is obtained by simulation in the reconstructed three-dimensional model.

[0047] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the winding has a coupling part in the complete sound field simulation calculation model;

[0048] The step of obtaining the vibration and noise simulation of the transformer based on the complete sound field simulation calculation model includes:

[0049] The coupling portion of the winding is hidden in the complete sound field simulation calculation model;

[0050] The complete sound field simulation calculation model is subjected to no-load simulation to obtain the vibration and noise simulation of the transformer.

[0051] Optionally, in the above-described step-by-step equivalent transformer vibration and noise simulation method, the step of obtaining the transformer vibration and noise simulation results based on the complete sound field simulation calculation model includes:

[0052] In the complete sound field simulation calculation model, a second attribute condition is set;

[0053] A load simulation was performed on the complete sound field simulation model to obtain the vibration and noise simulation results of the transformer.

[0054] The above-described one or more technical solutions provided by this invention can have the following advantages or at least achieve the following technical effects:

[0055] This invention proposes a step-by-step equivalent transformer vibration and noise simulation method. It obtains the deformation simulation results of the iron core under the influence of magnetostriction in a three-dimensional model of the iron core, and the vibration simulation results of the winding and the sound field distribution simulation results near the winding under vibration in a two-dimensional model of the winding. The three-dimensional model of the transformer is then reconstructed. Within this reconstructed model, the deformation simulation results of the iron core under the influence of magnetostriction, the vibration simulation results of the winding, and the sound field distribution simulation results near the winding under vibration are combined to calculate the transformer vibration and noise simulation. This method solves the coupling problem between models of different dimensions, reduces the computational complexity of transformer vibration and noise calculation, and by splitting the transformer vibration and noise simulation requirements, more simulation details can be achieved under the same solution scale compared to the overall model, resulting in higher simulation accuracy. This enables fast and relatively accurate transformer vibration and noise simulation. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a flowchart illustrating the step-by-step equivalent transformer vibration and noise simulation method of the present invention.

[0058] Figure 2 for Figure 1 A detailed flowchart of step S100;

[0059] Figure 3 for Figure 1 Detailed flowchart of step S200;

[0060] Figure 4 for Figure 1 Detailed flowchart of step S300;

[0061] Figure 5 for Figure 4 A detailed flowchart of an optional implementation of step S303;

[0062] Figure 6 for Figure 4 A detailed flowchart illustrating another optional implementation of step S303;

[0063] Figure 7 This is a schematic diagram of a three-dimensional model of the iron core involved in this invention;

[0064] Figure 8 This is a schematic diagram of a two-dimensional model of the winding involved in the present invention;

[0065] Figure 9 This is a schematic diagram of the reconstructed three-dimensional model involved in the present invention.

[0066] label name label name 100 core 200 winding 300 tank 400 transformer 500 pad block

[0067] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0069] It needs to be explained that,

[0070] In this embodiment of the invention, all directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0071] In this invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element. Furthermore, the meaning of "and / or" throughout the text includes three parallel options; for example, "A and / or B" includes option A, option B, or options where both A and B are satisfied.

[0072] In this invention, unless otherwise explicitly specified and limited, the terms "connection" and "fixed" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements.

[0073] In this invention, if there are descriptions involving "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0074] In this invention, the use of suffixes such as "module," "component," "part," "unit," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" can be used interchangeably.

[0075] For those skilled in the art, the specific meanings of the above terms in this invention can be understood according to the specific circumstances. Furthermore, the technical solutions of the various embodiments can be combined with each other; however, this is based on the premise that those skilled in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0076] The inventive concept of the present invention will be further explained below with reference to some specific embodiments.

[0077] This invention proposes a step-by-step equivalent transformer vibration and noise simulation method.

[0078] Reference Figure 1 , Figure 7 , Figure 8 and Figure 9 , Figure 1 This is a schematic diagram of the overall process of the step-by-step equivalent transformer vibration and noise simulation method of the present invention. Figure 7 This is a schematic diagram of a three-dimensional model of the iron core involved in the present invention. Figure 8 This is a schematic diagram of a two-dimensional model of the winding involved in the present invention. Figure 9 This is a schematic diagram of the reconstructed 3D model involved.

[0079] In one embodiment of the present invention, such as Figure 1 , Figure 7 , Figure 8 and Figure 9 As shown, a step-by-step equivalent simulation method for the vibration and noise of a transformer 400 is provided. The transformer 400 is installed inside an oil tank 300. The transformer 400 includes a core 100 and a winding 200 wound on the core 100. The method includes:

[0080] S100: Construct a three-dimensional model of the iron core 100 and calculate the magnetostriction of the iron core 100 under the influence of a magnetic field to obtain the deformation simulation results of the iron core 100 under the influence of the magnetostriction effect.

[0081] S200: Construct a two-dimensional model of the winding 200 and simulate the vibration of the winding 200 to obtain the vibration simulation results of the winding 200.

[0082] S300: Establish a reconstructed three-dimensional model including the core 100, clamps and oil tank 300 of the transformer 400, introduce the deformation simulation results of the core 100 under the influence of magnetostriction into the sound field simulation, use the vibration simulation results of the winding 200 as boundary conditions, and calculate the vibration noise of the transformer 400 in three dimensions.

[0083] For ease of understanding, a specific implementation method is shown below:

[0084] Based on the relative positional relationship between the oil tank 300 and the iron core 100, the magnetostriction of the iron core 100 of the transformer 400 is simulated.

[0085] In the model, construct the actual shape of the transformer 400 core 100 section, and simultaneously draw a simple cylindrical winding 200. Figure 7 As shown, the magnetic field distribution inside the iron core 100 is obtained, and the magnetic field distribution inside the iron core 100 in the three-dimensional model is approximately the actual magnetic field distribution of the iron core 100.

[0086] In the software, the magnetic field distribution generated by the winding 200 and the magnetostriction of the iron core 100 under the influence of the magnetic field are calculated in the three-dimensional model to obtain the deformation of the iron core 100 under the influence of the magnetostriction effect, thereby obtaining the deformation simulation results of the iron core 100 under the influence of the magnetostriction effect.

[0087] When simulating the vibration of winding 200, the vibration mainly originates from the Lorentz force acting on the current-carrying winding 200 under the leakage magnetic field. Due to the similarity of the three-phase windings 200 and the axisymmetric design of winding 200 itself, the three-dimensional model of core 100, oil tank 300, and winding 200 can be simplified into a two-dimensional axisymmetric model, obtaining a two-dimensional model of the oil tank 300, the core 100, and the winding 200, as shown below. Figure 8 As shown, the vibration of the winding 200 is simulated by using a barrel-shaped equivalent oil tank 300 and a columnar equivalent iron core 100. At the same time, based on this model, the sound field near the winding 200 is calculated, and the sound field distribution near the winding 200 under the vibration of the winding 200 is obtained through simulation. The vibration simulation results of the winding 200 and the sound field distribution simulation results near the winding 200 under the vibration of the winding 200 are obtained.

[0088] The integrated sound field simulation fully models the core 100, clamps and oil tank 300 of transformer 400 to obtain a reconstructed three-dimensional model;

[0089] In the reconstructed 3D model, the 200mm section of the winding is hollowed out and replaced with boundary conditions, as shown below. Figure 9 As shown, for the deformation of the core 100 of transformer 400, since a three-dimensional model is used, the deformation simulation results of the core 100 under the influence of magnetostriction obtained in S300 are directly introduced into the sound field simulation of the reconstructed three-dimensional model.

[0090] When solving the problem in conjunction with external structures such as clamps, the influence of other external structures on the vibration and deformation of the core 100 is considered in the acoustic field simulation of the reconstructed three-dimensional model. For the winding 200 part, the deformation of the end of the winding 200 in the axisymmetric model (the two-dimensional model of the oil tank 300 and the core 100) is first applied to the end face of the clamp winding 200 pressure plate to realize the joint calculation of the axisymmetric winding 200 and the three-dimensional clamp model.

[0091] The near-winding 200 sound field distribution obtained from the winding 200 model is used as a boundary condition and applied to the sound field simulation by generalized stretching (the solution obtained by two-dimensional axisymmetry is expanded to three-dimensional space, that is, the simulation results of the sound field distribution near the winding 200 under the vibration of the winding 200 obtained in the two-dimensional model of the oil tank 300 and the iron core 100 are expanded to the three-dimensional space of the reconstructed three-dimensional model). Vibration displacement is transferred and sound pressure isosurface is established by using operations such as average value transfer, uniform mapping, and generalized stretching to replace the three-dimensional winding 200 vibration calculation. Then, the no-load noise and load noise of the transformer 400 are calculated respectively.

[0092] Regarding the impact on the oil tank 300 of transformer 400, the vibration generated by the oil tank 300 of transformer 400 under the influence of sound waves and the final outward sound radiation are simulated and calculated through the acoustic-structural boundary.

[0093] By adjusting different excitation conditions of the winding 200 (no-load, short circuit, etc.), the vibration and noise of the transformer 400 under different operating conditions are simulated and calculated, and the vibration and noise simulation of the transformer 400 is obtained.

[0094] The technical solution of this invention obtains the deformation simulation results of the iron core 100 under the influence of magnetostriction effect in the three-dimensional model of the iron core 100, and obtains the vibration simulation results of the winding 200 and the sound field distribution simulation results near the winding 200 under the vibration condition in the two-dimensional model of the winding 200. It then reconstructs the three-dimensional model of the transformer 400, and combines the deformation simulation results of the iron core 100 under the influence of magnetostriction effect, the vibration simulation results of the winding 200, and the sound field distribution simulation results near the winding 200 under the vibration condition within the reconstructed three-dimensional model to calculate the vibration and noise simulation of the transformer 400. This solves the problem of mutual coupling between models of different dimensions, reduces the computational complexity of calculating the vibration and noise of the transformer 400, and by splitting the simulation requirements of the transformer 400 vibration and noise, more simulation details can be achieved under the same solution scale compared to the overall model, resulting in a higher level of simulation accuracy. This enables fast and relatively accurate simulation of the vibration and noise of the transformer 400.

[0095] In one embodiment, the steps of constructing a three-dimensional model of the iron core 100 and calculating the magnetostriction of the iron core 100 under the influence of a magnetic field to obtain the deformation simulation results of the iron core 100 under the influence of the magnetostriction effect include:

[0096] S110: Based on the actual shape of the winding 200 and the core 100, construct a three-dimensional model of the core 100, wherein the winding 200 has a cylindrical structure in the three-dimensional model of the core 100.

[0097] S120: In the three-dimensional model of the iron core 100, a magnetostrictive model of the iron core 100 is constructed based on the iron core 100 made of soft iron material.

[0098] S130: Calculate the magnetic field distribution generated by the winding 200 and the magnetostriction of the iron core 100 under the influence of the magnetic field to obtain the deformation simulation results of the iron core 100 under the influence of the magnetostriction effect.

[0099] S140: Based on the magnetization curve of the soft iron material, the interpolation data of the magnetization curve and the effective magnetization curve of the magnetostrictive model of the iron core 100 are corrected, and a first attribute condition is set in the magnetostrictive model of the iron core 100.

[0100] S150: Calculate the magnetostrictive model of the iron core 100 according to the first attribute condition to obtain the deformation simulation results of the iron core 100 under the influence of the magnetostrictive effect.

[0101] For ease of understanding, a specific implementation method is shown below:

[0102] Regarding the main magnetic flux and magnetostriction of the core: To study the no-load vibration characteristics of transformer 400 using the finite element method, it is necessary to know the distribution of the main magnetic flux in core 100 and the corresponding BH curve (magnetization curve) of the silicon steel sheets. Therefore, the common solution approach is to establish a finite element model of transformer 400 and use field-circuit coupling to solve for the excitation current and the main magnetic flux in core 100 in the time domain. However, due to the nonlinear excitation characteristics of core 100, the established three-dimensional model is complex with a large number of meshes. The scale and time required for nonlinear calculations using field-circuit coupling are substantial, making the solution very difficult. Therefore, appropriate equivalent and superposition methods are needed.

[0103] A simulation study was conducted on the magnetostrictive characteristics of transformer 400, such as... Figure 7 As shown, the completed iron core 100 and simplified winding 200 entities are the three-dimensional models of the iron core 100, and an air domain slightly larger than this size is established.

[0104] Iron core 100 material is a soft iron material. Based on the BH curve of the material, the interpolation data of the BH curve and the effective BH curve in the material properties are modified. Magnetostriction and orthotropic series properties are added as the first property conditions. The first property condition of the magnetostriction property is set according to the material used.

[0105] Based on the proposed anisotropic equivalent method for the mechanical properties of a 100mm thick laminated core structure, calculations were performed on the laminated structure of silicon steel sheets with a thickness of 0.30mm:

[0106] Where H is the total thickness of core 100, α is the lamination factor of the silicon steel sheets (α = 97.5%), μ is the stiffness correction introduced by the fixed casting of core 100, and μ = 9.32 in a circular lamination arrangement, and G is the Young's modulus or shear modulus of the material. The calculated correction factor is G. n =G' / G=7.7855×10 -4 Based on the direction of the elastic modulus and shear modulus affected by the laminated structure, the orthogonal anisotropy parameters of the material are set to complete the setting of the first attribute conditions. Based on the first attribute conditions, the laminated structure of the silicon steel sheets in the magnetostrictive model of the iron core 100 is calculated to obtain the deformation simulation results of the iron core 100 under the influence of the magnetostrictive effect.

[0107] Continue to refer to Figure 1 and Figure 7 and refer to Figure 2 , Figure 2 for Figure 1 A detailed flowchart of step S100.

[0108] In one embodiment of the present invention, such as Figure 1 , Figure 2 and Figure 7 As shown, the step of constructing a magnetostrictive model of the iron core 100 based on the soft iron material in the three-dimensional model of the iron core 100 includes:

[0109] S121: Set a first constraint condition in the three-dimensional model constructed based on the iron core 100 of the soft iron material;

[0110] S122: According to the first constraint condition, the iron core 100 in the three-dimensional model is set as the domain to be solved;

[0111] S123: Set a second constraint condition in the domain to be solved, and obtain the solution result according to the second constraint condition;

[0112] S124: Obtain the magnetostrictive model of the iron core 100 based on the solution results.

[0113] For ease of understanding, a specific implementation method is shown below:

[0114] In the physical field - magnetic field, apply the (Ampere's law, magnetostriction) condition to the iron core 100 affected by magnetostriction, and add three-phase windings 200 of A, B, and C as domain coils. In the expanded geometric analysis, select a section of winding 200, and define the three-phase windings 200 in the same direction, and use this as the first constraint condition.

[0115] Based on the actual voltage conditions of transformer 400, the coil excitation is set to voltage form, and the excitation voltage is set to be 120° different for each of the three phases, which can be expressed using phasor method;

[0116] Considering that the main calculation is required for the magnetostriction of core 100, the magnetic field distribution of winding 200 does not need to be calculated precisely, so a uniform multi-turn conductor model is selected.

[0117] In the solid mechanics field, select the linear elastic material domain condition, change the solid model therein to orthogonal anisotropy, and in the magnetostrictive domain condition, change the magnetostrictive model to nonlinear isotropy, and use this as the second constraint condition.

[0118] The magnetostrictive model of iron core 100 is now complete. During the analysis, first, a coil geometry analysis is added to solve for the coil in the magnetic field. Then, a frequency domain analysis is added to calculate the magnetostrictive vibration of iron core 100. Based on the solution results, the magnetostrictive model of iron core 100 and the deformation simulation results of iron core 100 under the influence of magnetostrictive effect are obtained.

[0119] Continue to refer to Figure 1 and Figure 8 and refer to Figure 3 , Figure 3 for Figure 1 A detailed flowchart of step S200.

[0120] In one embodiment of the present invention, such as Figure 1 , Figure 3 and Figure 8 As shown, the steps of constructing a two-dimensional model of the winding 200 and simulating the vibration of the winding 200 to obtain the vibration simulation results of the winding 200 include:

[0121] S210: Construct a two-dimensional model of the winding 200 based on its actual shape;

[0122] S220: Construct two-dimensional models of the oil tank 300, iron core 100 and pad block 500 in the two-dimensional model, and simulate the vibration of the winding 200 to obtain the vibration simulation results of the winding 200.

[0123] For ease of understanding, a specific implementation method is shown below:

[0124] Simulation analysis of vibration and noise of transformer 400: Based on the simulation of the vibration of the core 100 of transformer 400 under no-load conditions, the magnetic field distribution generated by the winding 200 under load conditions is analyzed by using a two-dimensional axisymmetric method. The vibration of the winding 200 under load conditions is calculated and coupled to the calculation of the sound field, thereby realizing the analysis of vibration and noise of transformer 400 under load conditions.

[0125] The two-dimensional model of the core 100 is an axisymmetric model. The axisymmetric model analyzes the stress on the winding 200 part through the magnetic field and couples it to solid mechanics to calculate the deformation of the winding 200. Then, through pressure acoustics, it calculates the sound pressure in the transformer 400 oil. Therefore, in the solid mechanics calculation, only the winding 200 and the pressure plate part need to be calculated, while in the sound pressure calculation, only the oil channels (between the pads) between the layers of winding 200 and the oil part of transformer 400 are calculated. At this time, except for the axial constraint of winding 200 which is not yet clear, all other coupling conditions have been established. The axial constraint of winding 200 is not suitable to be applied in this component due to the limitation of the two-dimensional axisymmetric model. Instead, it is calculated in the three-dimensional model of the fixing component. Therefore, the method of obtaining the vibration simulation results of winding 200 in the two-dimensional model of core 100 reduces the computational complexity of transformer 400 vibration and noise calculation. By splitting the simulation requirements of transformer 400 vibration and noise, more simulation details can be achieved under the same solution scale compared with the overall model, and a higher simulation accuracy level can be achieved. This enables fast and relatively accurate simulation of transformer 400 vibration and noise.

[0126] In one embodiment, the transformer 400 includes a clamp that clamps the winding 200;

[0127] The steps of establishing a reconstructed three-dimensional model of the transformer 400, including the core 100, clamps, and oil tank 300, incorporating the deformation simulation results of the core 100 under the influence of magnetostriction into the sound field simulation, and using the vibration simulation results of the winding 200 as boundary conditions to calculate the vibration noise of the transformer 400 in three dimensions include:

[0128] S310: Completely model the iron core 100, the winding 200, the clamp and the oil tank 300 within the three-dimensional model of the iron core 100 to obtain the three-dimensional model to be integrated;

[0129] S320: Based on the vibration simulation results of the winding 200, obtain the boundary conditions of the winding 200;

[0130] S330: Replace the region in the three-dimensional model to be integrated with the actual position of the winding 200 according to the boundary conditions of the winding 200, and obtain the reconstructed three-dimensional model.

[0131] It should be noted that in step S320, the boundary condition of winding 200 is the near-winding 200 sound field distribution calculated by the winding 200 model in the two-dimensional model.

[0132] Continue to refer to Figure 1 , Figure 7 , Figure 8 and Figure 9 and refer to Figure 4 , Figure 4 for Figure 1 A detailed flowchart of step S300.

[0133] In one embodiment of the present invention, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 4 As shown, the steps of establishing a reconstructed three-dimensional model of the transformer 400, including the core 100, clamps, and oil tank 300, incorporating the deformation simulation results of the core 100 under the influence of magnetostriction into the sound field simulation, and using the vibration simulation results of the winding 200 as boundary conditions to calculate the vibration noise of the transformer 400 in three dimensions include:

[0134] S301: Perform sound field simulation on the reconstructed three-dimensional model to obtain the sound field simulation results of the reconstructed three-dimensional model;

[0135] S302: Combine the deformation simulation results of the iron core 100 under the influence of magnetostriction effect with the sound field simulation results to obtain the first sound field simulation quantity;

[0136] S303: Combine the vibration simulation results of the winding 200 and the sound field simulation results to obtain the second sound field simulation quantity;

[0137] S304: Combine the first sound field simulation quantity and the second sound field simulation quantity to obtain a complete sound field simulation calculation model;

[0138] S305: Based on the complete sound field simulation calculation model, obtain the vibration and noise simulation of the transformer 400.

[0139] For ease of understanding, a specific implementation method is shown below:

[0140] To calculate the constraint effect of the transformer 400 structural components and the external sound field of the transformer 400, a three-dimensional simulation model is needed, including the transformer 400 core 100, structural components, and the sound radiation surface of the winding 200. Based on the existing model, a new three-dimensional component is added, using the core 100 model from the core 100 vibration analysis component, and adding external fixed structural components to the core 100. In addition to the core 100, the sound radiation surface of the winding 200, the oil tank 300, and the external sound field calculation area also need to be added. To minimize the difference in sound field distribution between the two-dimensional axisymmetric barrel-shaped oil tank 300 and the actual square oil tank 300, the sound radiation surface of the winding 200 should be selected as close as possible to the outermost part of the winding 200. The oil tank 300 is built according to the actual size of the transformer 400 oil tank 300. Since the transformer 400 is placed on the ground, only the part above the ground needs to be calculated. Therefore, a hemisphere is used to draw the air domain, and a perfectly matched layer is added outside the hemisphere to simulate the sound field performance under an infinitely large air domain.

[0141] Since the thickness of the transformer 400 oil tank 300 is not modeled, the shell needs to be calculated in the simulation physics. The physics fields to be added in the simulation are: solid mechanics, shell (solid mechanics), pressure acoustics, and frequency domain. The solid mechanics part is used for the deformation calculation of the core 100 and its fixing structure, and the calculation domain includes the core 100 and the fixing parts; the shell is only solved for the transformer 400 oil tank 300, and the calculation boundary is the outer shell of the transformer 400 oil tank 300; pressure acoustics is used to calculate the sound field distribution, and the calculation needs to include the external perfectly matched layer, the air domain, and the oil part of the transformer 400.

[0142] The transmission of vibration from winding 200 to the core 100 structural component is also achieved by specifying displacement boundary conditions. Since the vibration of winding 200 is simulated in a two-dimensional axisymmetric model, while the sound field simulation is performed in a three-dimensional model, consistent mapping cannot be used. Therefore, the displacement of the end face is averaged to map the displacement of the winding 200 end to the displacement at the connection between the core 100 structural component and the winding 200 pressure plate in the sound field simulation.

[0143] The vibration sound field of winding 200 calculated in the axisymmetric model of winding 200 is mapped to the sound field simulation model using a generalized stretching method.

[0144] For the tank 300 part of transformer 400, in the shell physics field, add a fixed constraint on the bottom of tank 300, and set the thickness of tank 300 in thickness and offset.

[0145] At this point, the simulation model of transformer 400 core 100, winding 200, oil tank 300 and external sound field has been completed, that is, the construction of the reconstructed three-dimensional model is completed.

[0146] For the constructed simulation model, i.e., the reconstructed three-dimensional model, it is first necessary to calculate the magnetostriction of the core 100 and the vibration of the winding 200 under current-carrying conditions. That is, in the study, firstly, the coil geometry analysis is performed on the coil boundary in the magnetic field of the core 100 model and the axisymmetric model of the winding 200. Then, the deformation simulation results of the core 100 under the influence of magnetostriction, the vibration simulation results of the winding 200, and the sound field distribution simulation results near the winding 200 under the vibration of the winding 200 are combined. Then, the magnetic field in the axisymmetric model of the winding 200 is calculated by the steady-state solution method. Finally, the other physical fields are calculated together to obtain the sound radiation distribution outside the transformer 400.

[0147] For no-load test conditions, since the current flowing through winding 200 is small, the vibration generated by winding 200 is also relatively small. Therefore, the axisymmetric component of winding 200 does not need to be solved, and the coupling part with winding 200 in the sound field simulation model is removed to reduce the amount of simulation calculation.

[0148] For load test conditions, since the magnetic flux of core 100 is relatively small, the influence of magnetostriction of core 100 can be ignored to a certain extent. Therefore, the vibration model of core 100 does not need to be calculated. In the sound field simulation model, changing the constraint to a free constraint can reduce the amount of simulation calculation under load test conditions and speed up the calculation of the simulation model.

[0149] Continue to refer to Figure 1 , Figure 7 , Figure 8 and Figure 9 and refer to Figure 5 , Figure 5 for Figure 4 A detailed flowchart of an optional implementation of step S303.

[0150] In one embodiment of the present invention, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 4 As shown, the clamp is connected to a winding 200 pressure plate;

[0151] The step of combining the vibration simulation results and the sound field simulation results to obtain the second sound field simulation quantity includes:

[0152] A313: Within the two-dimensional model of the winding 100, obtain the deformation of the end of the winding 200;

[0153] A314: The deformation at the end of the winding 200 is taken as the second constraint condition;

[0154] A315: Based on the second constraint, the second sound field simulation quantity is obtained by simulation in the reconstructed three-dimensional model.

[0155] In step A315, the second constraint condition is obtained by applying the deformation of the end of the winding 200 to the end face of the pressure plate, and the vibration simulation result is imported into the reconstructed three-dimensional model for simulation to obtain the second sound field simulation quantity.

[0156] Continue to refer to Figure 1 , Figure 7 , Figure 8 and Figure 9 and refer to Figure 6 , Figure 6 for Figure 4 A detailed flowchart illustrating another optional implementation of step S303.

[0157] In one embodiment of the present invention, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 6 As shown, the vibration simulation results include sound field distribution simulation results;

[0158] The step of combining the vibration simulation results and the sound field simulation results to obtain the second sound field simulation quantity includes:

[0159] B313: In the two-dimensional model of the winding 200, the sound field distribution near the winding 200 under the condition of vibration of the winding 200 is simulated.

[0160] B314: Based on the sound field distribution near the winding 200 under the condition of vibration of the winding 200, obtain the sound field distribution result near the winding 200;

[0161] B315: The sound field distribution result of the winding 200 is used as the third constraint condition;

[0162] B316: Based on the third constraint condition, the second sound field simulation quantity is obtained by simulation in the reconstructed three-dimensional model.

[0163] In one specific embodiment, the sound field distribution result of the near winding 200 is calculated in the two-dimensional model of the winding 100. The sound field distribution result of the near winding 200 is set as the boundary condition, i.e. the third constraint condition. The sound field distribution result of the near winding 200 is imported into the sound field simulation in the reconstructed three-dimensional model by generalized stretching to obtain the third sound field simulation quantity.

[0164] As an alternative to this embodiment, in the complete sound field simulation calculation model, the winding 200 has a coupling part;

[0165] The step of obtaining the vibration and noise simulation of the transformer 400 based on the complete sound field simulation calculation model includes:

[0166] T351: The coupling part of the winding 200 is hidden in the complete sound field simulation calculation model;

[0167] T352: Perform no-load simulation on the complete sound field simulation calculation model to obtain the vibration and noise simulation of the transformer 400.

[0168] In one specific embodiment, the complete simulation calculation model is subjected to no-load excitation, and the coupling part of the complete simulation calculation model with the winding 200 is removed to calculate the vibration and noise simulation of the transformer 400.

[0169] As another option in this embodiment, the step of obtaining the vibration and noise simulation of the transformer 400 based on the complete sound field simulation calculation model includes:

[0170] E351: In the complete sound field simulation calculation model, set the second attribute condition;

[0171] E352: Perform load simulation on the complete sound field simulation calculation model to obtain the vibration and noise simulation of the transformer 400.

[0172] In one specific implementation, the complete simulation calculation model is subjected to load excitation, and the constraints in the complete simulation calculation model are changed to free constraints, i.e., second attribute conditions, to calculate and obtain the vibration and noise simulation of the transformer 400.

[0173] It should be noted that the sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above embodiments are only optional embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made under the inventive concept of the present invention using the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are all included within the patent protection scope of the present invention.

Claims

1. A step-by-step equivalent transformer vibration and noise simulation method, characterized in that, The transformer is installed inside an oil tank. The transformer includes an iron core, windings wound on the iron core, and clamps clamped to the windings. The method includes: A three-dimensional model of the iron core is constructed, and the magnetostriction of the iron core under the influence of a magnetic field is calculated to obtain the deformation simulation results of the iron core under the influence of the magnetostriction effect. A two-dimensional model of the winding is constructed, and the vibration of the winding is simulated to obtain the vibration simulation results of the winding. Within the three-dimensional model of the iron core, the winding, the clamp and the oil tank are fully modeled to obtain the three-dimensional model to be integrated; Based on the vibration simulation results of the winding, the boundary conditions of the winding are obtained; Based on the boundary conditions of the winding, replace the region in the three-dimensional model to be integrated with the actual position of the winding to obtain the reconstructed three-dimensional model; A sound field simulation is performed on the reconstructed three-dimensional model to obtain the sound field simulation results of the reconstructed three-dimensional model; the deformation simulation results of the iron core under the influence of magnetostriction effect and the sound field simulation results are combined to obtain the first sound field simulation quantity; By combining the vibration simulation results of the winding and the sound field simulation results, a second sound field simulation quantity is obtained; By combining the first sound field simulation quantity and the second sound field simulation quantity, a complete sound field simulation calculation model is obtained; Based on the complete sound field simulation calculation model, the vibration and noise simulation of the transformer is obtained.

2. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 1, characterized in that, The steps of constructing a three-dimensional model of the iron core and calculating the magnetostriction of the iron core under the influence of a magnetic field to obtain the deformation simulation results of the iron core under the influence of the magnetostriction effect include: Based on the actual shape of the winding and the core, a three-dimensional model of the core is constructed, and the winding is in the form of a cylindrical structure in the three-dimensional model of the core; In the three-dimensional model of the iron core, a magnetostrictive model of the iron core is constructed based on the iron core made of soft iron material; The magnetic field distribution generated by the winding and the magnetostriction of the iron core under the influence of the magnetic field are calculated to obtain the deformation simulation results of the iron core under the influence of the magnetostriction effect. Based on the magnetization curve of the soft iron material, the interpolation data of the magnetization curve and the effective magnetization curve of the magnetostrictive model of the iron core are corrected, and a first attribute condition is set in the magnetostrictive model of the iron core. The magnetostrictive model of the iron core is calculated based on the first attribute condition to obtain the deformation simulation results of the iron core under the influence of the magnetostrictive effect.

3. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 2, characterized in that, The step of constructing a magnetostrictive model of the iron core based on the soft iron material in the three-dimensional model of the iron core includes: In the three-dimensional model constructed based on the iron core of the soft iron material, a first constraint condition is set; the first constraint condition includes applying Ampere's law condition to the iron core affected by magnetostriction, adding a three-phase winding as a domain coil, and selecting the winding cross section and defining the direction in the geometric analysis; Based on the first constraint, the iron core in the three-dimensional model is set as the domain to be solved; A second constraint condition is set in the domain to be solved, and the solution result is obtained according to the second constraint condition; the second constraint condition includes changing the solid model to orthogonal anisotropy in the linear elastic material domain condition, and changing the magnetostrictive model to nonlinear isotropy in the magnetostrictive domain condition; The magnetostrictive model of the iron core is obtained based on the solution results.

4. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 1, characterized in that, The steps of constructing a two-dimensional model of the winding and simulating the vibration of the winding to obtain the vibration simulation results of the winding include: Based on the actual shape of the winding, a two-dimensional model of the winding is constructed; Two-dimensional models of the oil tank, iron core, and pad block are constructed in the two-dimensional model, and the vibration of the winding is simulated to obtain the vibration simulation results of the winding.

5. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 1, characterized in that, The clamp is connected to a winding pressure plate; The step of combining the vibration simulation results and the sound field simulation results to obtain the second sound field simulation quantity includes: Within the two-dimensional model of the winding, the deformation of the winding ends is obtained; The deformation at the end of the winding is used as the second constraint condition; Based on the second constraint, the second sound field simulation quantity is obtained by simulation in the reconstructed three-dimensional model.

6. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 1, characterized in that, The vibration simulation results include sound field distribution simulation results; The step of combining the vibration simulation results and the sound field simulation results to obtain the second sound field simulation quantity includes: In the two-dimensional model of the winding, the sound field distribution near the winding is obtained by simulation under the condition of winding vibration; Based on the sound field distribution near the winding under the condition of winding vibration, the sound field distribution result near the winding is obtained; The sound field distribution of the winding is used as the third constraint condition; Based on the third constraint, the second sound field simulation quantity is obtained by simulation in the reconstructed three-dimensional model.

7. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 1, characterized in that, In the complete sound field simulation calculation model, the winding has a coupling part; The step of obtaining the vibration and noise simulation of the transformer based on the complete sound field simulation calculation model includes: The coupling portion of the winding is hidden in the complete sound field simulation calculation model; The complete sound field simulation calculation model is subjected to no-load simulation to obtain the vibration and noise simulation of the transformer.

8. The step-by-step equivalent transformer vibration and noise simulation method as described in claim 1, characterized in that, The step of obtaining the vibration and noise simulation of the transformer based on the complete sound field simulation calculation model includes: In the complete sound field simulation calculation model, a second attribute condition is set; A load simulation was performed on the complete sound field simulation model to obtain the vibration and noise simulation results of the transformer.

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