Equivalent simulation method, system, computer device and computer readable storage medium

Abstract

The present invention discloses an equivalent simulation method considering the stator stacking structure of a motor, including: establishing a three-dimensional finite element grid of a stator core and equivalent mass points of a stator winding and associating the three-dimensional finite element grid of a stator core and equivalent mass points of a stator winding to form a three-dimensional finite element model of a stator; determining material parameters and analyzing the influence of the values ​​of the material parameters on the stator modal frequency; selecting target material parameters and iteratively correcting the values ​​of the target material parameters until the deviation between the stator modal simulation result obtained by simulating the three-dimensional finite element model and the stator modal test result is within the target range, and then stopping the iteration; assigning the corrected target material parameters to the stator three-dimensional finite element model to perform stator modal simulation. The present invention also discloses an equivalent simulation system, a computer device and a computer-readable storage medium considering the stator stacking structure of a motor. By adopting the present invention, only one solid model needs to be constructed, which can reduce material parameters, is easy to control, and improves simulation accuracy.

Description

Technical Field

[0001] The present invention relates to the field of modal simulation technology, and in particular to an equivalent simulation method, system, computer equipment and computer-readable storage medium taking into account the stator stacking structure of a motor. Background Art

[0002] With the rapid development of the new energy vehicle industry in recent years, the noise problem of new energy vehicles has attracted more and more attention. Unlike traditional internal combustion engine vehicles, the noise of new energy vehicles, especially pure electric vehicles, mainly comes from the drive motor. Although the total value of the noise is not large, the frequency is high, which can easily cause troubles to drivers and passengers. Motor noise is mainly generated by the vibration of the stator and casing under electromagnetic force excitation. Therefore, accurate finite element modeling and modal analysis of the motor stator is the key to studying motor noise.

[0003] In the motor design process, in order to reduce the eddy current loss of the stator, the stator core is usually made of very thin silicon steel sheets stacked along the axial direction, and the windings placed in the stator slots are made of copper wires. Therefore, the stator core and windings are both stacked structures rather than solid structures, which brings great difficulties to the modal simulation of the motor stator.

[0004] Among the existing motor stator modal simulation methods, most of them model the stator core and winding as physical structures, and then assign material parameters of silicon steel sheets and copper respectively. The simulation results have a large deviation from the experimental test results; a small number of them also model the stator core and winding as physical structures, and then assign anisotropic material parameters to them respectively. This method requires the determination of equivalent anisotropic material parameters of the stator core and winding separately. There are many parameters to be determined, and two modal tests are required, which is labor-intensive and difficult to control in terms of accuracy. In addition, none of the existing methods control the stator finite element modeling and meshing process, which will also introduce additional errors. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an equivalent simulation method, system, computer equipment and computer-readable storage medium that take into account the stacked structure of the motor stator. Only one solid model needs to be constructed, which can effectively reduce material parameters, facilitate control and improve simulation accuracy.

[0006] In order to solve the above technical problems, the present invention provides an equivalent simulation method considering the stator stacking structure of a motor, including: establishing a three-dimensional finite element mesh of a stator core and equivalent mass points of a stator winding, and associating the three-dimensional finite element mesh of the stator core and the equivalent mass points of the stator winding to form a three-dimensional finite element model of a stator; determining material parameters related to stator modal simulation results according to the characteristics of anisotropic materials, and using the three-dimensional finite element model of the stator to analyze the influence of the values ​​of the material parameters on the stator modal frequency; selecting target material parameters from the material parameters according to the influence law, and iteratively correcting the values ​​of the target material parameters until the deviation between the stator modal simulation results obtained by simulating the three-dimensional finite element model and the stator modal test results is within the target range, and then stopping the iteration; using the corrected target material parameters as equivalent material parameters of the stator and assigning them to the three-dimensional finite element model of the stator to perform stator modal simulation.

[0007] As an improvement of the above scheme, the steps of establishing a three-dimensional finite element mesh of the stator core and equivalent mass points of the stator winding, and associating the three-dimensional finite element mesh of the stator core and the equivalent mass points of the stator winding to form a three-dimensional finite element model of the stator include: constructing a three-dimensional finite element mesh of the stator core; constructing an equivalent mass point of the stator winding at the geometric center position of the stator core; connecting the equivalent mass point of the stator winding with the mesh nodes on the surface of each stator tooth in the three-dimensional finite element mesh of the core to evenly distribute the mass of the stator winding to each stator tooth; and determining the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding.

[0008] As an improvement of the above scheme, the step of constructing a three-dimensional finite element mesh of the stator core includes: constructing a two-dimensional plane model of stator teeth; meshing the two-dimensional plane model of stator teeth to generate a two-dimensional plane mesh of stator teeth; performing circumferential rotation array on the two-dimensional plane mesh of stator teeth to generate a two-dimensional plane mesh of stator section; stretching the two-dimensional plane mesh of stator section along the axial direction of the stator to generate a three-dimensional finite element mesh of the stator core.

[0009] As an improvement of the above solution, the step of constructing a two-dimensional plane model of stator teeth includes: drawing a two-dimensional plane model of stator teeth according to geometric parameters of the motor stator, or cutting out a two-dimensional plane model of stator teeth from a preset three-dimensional finite element model of stator teeth.

[0010] As an improvement of the above scheme, the steps of determining the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding include: calculating the equivalent density of the stator core according to the formula ρ=m / v, wherein ρ is the equivalent density of the stator core, m is the mass of the actual stator core, and v is the volume of the three-dimensional finite element mesh of the stator core; and taking the mass of the actual stator winding as the mass of the equivalent mass point of the stator winding.

[0011] As an improvement of the above scheme, the steps of determining material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material and using the stator three-dimensional finite element model to analyze the influence of the material parameter values ​​on the stator modal frequency include: determining the independent material parameters of the anisotropic material according to the characteristics of the stator laminated structure; assigning initial values ​​to the independent material parameters; changing the value of any independent material parameter and keeping the other independent material parameters fixed, and using the stator three-dimensional finite element model to simulate and analyze the change of the stator modal frequency with the independent material parameters; and using the same method to analyze the change of the stator modal frequency with other independent material parameters.

[0012] As an improvement of the above scheme, the step of iteratively correcting the value of the target material parameter until the deviation between the stator modal simulation result obtained by the three-dimensional finite element model simulation and the stator modal test result is within the target range and then stopping the iteration includes: assigning a value to the target material parameter, and using the three-dimensional finite element model to perform modal simulation on the stator to generate a stator modal simulation result; comparing the stator modal simulation result with the test result, if the deviation between the stator modal simulation result and the test result exceeds the target range, reassigning the target material parameter until the deviation between the stator modal simulation result and the test result is within the target range and then stopping the iteration.

[0013] Correspondingly, the present invention also provides an equivalent simulation system considering the stator stacking structure of the motor, including: a model construction module, used to establish a three-dimensional finite element grid of the stator core and equivalent mass points of the stator winding, and associate the three-dimensional finite element grid of the stator core and the equivalent mass points of the stator winding to form a three-dimensional finite element model of the stator; a law analysis module, used to determine the material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material, and use the stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency; an iterative correction module, used to select target material parameters from the material parameters according to the influence law, and iteratively correct the values ​​of the target material parameters until the deviation between the stator modal simulation results obtained by the three-dimensional finite element model simulation and the stator modal test results is within the target range, and the iteration is stopped; a modal simulation module, used to use the corrected target material parameters as the equivalent material parameters of the stator and assign them to the stator three-dimensional finite element model to perform stator modal simulation.

[0014] As an improvement of the above scheme, the model construction module includes: a grid construction unit, used to construct a three-dimensional finite element grid of the stator core; a mass point construction unit, used to construct an equivalent mass point of the stator winding at the geometric center position of the stator core; an association unit, used to connect the equivalent mass point of the stator winding with the grid node on the surface of each stator tooth in the three-dimensional finite element grid of the core, so as to evenly distribute the mass of the stator winding to each stator tooth; a parameter determination unit, used to determine the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding.

[0015] Correspondingly, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the above-mentioned equivalent simulation method.

[0016] Accordingly, the present invention also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the equivalent simulation method are implemented.

[0017] The implementation of the present invention has the following beneficial effects:

[0018] The present invention treats the stator winding as equivalent to a mass point instead of establishing a solid model of the stator winding, and associates the stator winding as equivalent to a mass point with a three-dimensional finite element grid of the stator core to form a three-dimensional finite element model of the stator. Therefore, the present invention only needs to perform one modal test, which greatly reduces the workload of the simulation method.

[0019] At the same time, the present invention uses anisotropic material parameters related to the stator modal simulation results to equivalently consider the stacked structure of the stator core and the stator winding, with fewer material parameters, easy control of accuracy and high simulation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of a first embodiment of an equivalent simulation method considering a motor stator laminated structure of the present invention;

[0021] Figure 2 is a flow chart of a second embodiment of an equivalent simulation method considering a motor stator laminated structure of the present invention;

[0022] Figure 3 is a schematic diagram of constructing a three-dimensional finite element mesh of a stator core in the present invention;

[0023] Figure 4 It is a structural schematic diagram of an equivalent simulation system considering the motor stator laminated structure of the present invention;

[0024] Figure 5 It is a structural schematic diagram of the model building module in the present invention. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] See also Figure 1 , Figure 1 The flowchart of the first embodiment of the equivalent simulation method considering the stator lamination structure of the motor of the present invention is shown, comprising:

[0027] S101, establishing a three-dimensional finite element mesh of a stator core and equivalent mass points of a stator winding, and associating the three-dimensional finite element mesh of the stator core and the equivalent mass points of the stator winding to form a three-dimensional finite element model of a stator.

[0028] The existing simulation method requires to establish entity models for the stator core and stator winding respectively, so two modal tests need to be performed; different from the prior art, in the present invention, the stator winding is equivalent to a mass point and there is no need to establish an entity model of the winding, so only one modal test is required. In summary, the method provided by the present invention has less workload, fewer parameters to be determined, easy to control accuracy, and high simulation accuracy.

[0029] S102, determining material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material, and using the stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency.

[0030] Specifically, the steps of determining material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material and using a stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency include:

[0031] (1) Determine the independent material parameters of the anisotropic material based on the characteristics of the stator laminated structure.

[0032] (2) Assigning initial values ​​to the independent material parameters.

[0033] (3) Changing the value of any independent material parameter and keeping other independent material parameters fixed, using the stator three-dimensional finite element model to simulate and analyze the variation of the stator modal frequency with the independent material parameters.

[0034] (4) The same method is used to analyze how the stator modal frequency changes with other independent material parameters.

[0035] It should be noted that the idea of ​​the present invention is to use virtual anisotropic materials to equivalently consider the stacked structure of the stator core and stator winding. Therefore, to perform modal simulation on the motor stator, it is necessary to first determine the parameters of the anisotropic material. To determine the values ​​of these parameters, it is necessary to first study the influence of each parameter on the stator mode.

[0036] Since the three elastic constants of anisotropic materials (Young's modulus, shear modulus and Poisson's ratio) have a total of 9 material parameters, and these material parameters are not all independent of each other, it is necessary to determine the independent material parameters among these 9 material parameters (that is, the material parameters related to the stator modal simulation results) according to the laminated structure characteristics of the stator.

[0037] Specifically, the three elastic constants of anisotropic materials (Young's modulus E, shear modulus G and Poisson's ratio V) have a total of 9 material parameters, namely Young's modulus in three directions (Ex, Ey, Ez), shear modulus in three planes (Gxy, Gyz, Gzx) and three Poisson's ratios (vxy, vyz, vzx). Figure 3 As shown in the figure, since the stator core is made of silicon steel sheets stacked in the axial direction (z direction), the plane (xy plane) where the silicon steel sheets are located is an isotropic plane, so Ex = Ey, Gyz = Gzx. At the same time, since the variation range of the Poisson's ratio of metal materials is very small and the influence of the Poisson's ratio on the modal frequency is not significant, it is directly assumed that vxy = vyz = vzx = 0.3. Therefore, there are only 4 independent material parameters among the 9 material parameters of the anisotropic material equivalent to the stator core, namely Ex (Ey), Ez, Gxy and Gyz (Gzx).

[0038] In addition, the influence of each independent material parameter (Ex (Ey), Ez, Gxy and Gyz (Gzx)) on the stator modal frequency is analyzed. Specifically, the value of one of the independent material parameters is changed while keeping the other independent material parameters fixed. Then, the stator three-dimensional finite element model is used to perform modal simulation on the stator, and the change pattern of the stator modal frequency with each independent material parameter is observed.

[0039] For example, for a 48-slot stator of a new energy vehicle drive motor, let the three independent material parameters of the anisotropic material be Ez = 210Gpa, Gxy = Gyz (Gzx) = 80.77Gpa (the material parameters of the silicon steel sheet are Ex = Ey = Ez = 210Gpa, Gxy = Gyz = Gzx = 80.77Gpa), and then the value of Ex (Ey) is evenly reduced from 210Gpa to 21Gpa in ten steps. The stator modal frequency and stator modal vibration shape of each step can be obtained through modal simulation. At the same time, the same method is used to study the influence of the other three independent material parameters on the stator modal frequency. The results show that the Young's modulus Ex(Ey) in the x(y) direction and the shear modulus Gxy in the xy plane have a great influence on the modal frequency of the stator radial mode, and the modal frequency of the stator radial mode decreases with the decrease of Ex(Ey) and Gxy, while the Young's modulus Ez in the z direction and the shear modulus Gyz(Gzx) in the yz(zx) plane have almost no effect on the modal frequency of the stator radial mode; the Young's modulus Ex(Ey) in the x(y) direction, the shear modulus Gxy in the xy plane and the shear modulus Gyz(Gzx) in the yz(zx) plane have a great influence on the modal frequency of the stator antisymmetric mode, while the Young's modulus Ez in the z direction has almost no effect on the modal frequency of the stator antisymmetric mode. Therefore, the Young's modulus Ex(Ey), shear modulus Gxy and shear modulus Gyz(Gzx) have a great influence on the stator modal frequency.

[0040] S103, selecting a target material parameter from the material parameters according to the influencing rule, and iteratively correcting the value of the target material parameter until the deviation between the stator modal simulation result obtained by simulating the three-dimensional finite element model and the stator modal test result is within a target range and the iteration is stopped.

[0041] In order to quickly determine the equivalent anisotropic material parameters of the stator and make the stator modal simulation results close to the experimental results, it is necessary to focus on those material parameters that have a great influence on the stator modal frequency. Therefore, in general, the material parameters that have a great influence on the stator modal frequency are used as target material parameters. For example, for a 48-slot stator of a new energy vehicle drive motor, Young's modulus Ex (Ey), shear modulus Gxy and shear modulus Gyz (Gzx) have a great influence on the stator modal frequency and can be used as target material parameters.

[0042] Specifically, the step of iteratively correcting the value of the target material parameter until the deviation between the stator modal simulation result obtained by the three-dimensional finite element model simulation and the stator modal test result is within the target range and then stopping the iteration includes:

[0043] (1) Assigning values ​​to the target material parameters, and using the three-dimensional finite element model to perform modal simulation on the stator to generate stator modal simulation results.

[0044] (2) Comparing the stator modal simulation results with the test results, if the deviation between the stator modal simulation results and the test results exceeds the target range, returning to step (1) to reassign the target material parameters, and stopping the iteration until the deviation between the stator modal simulation results and the test results is within the target range.

[0045] It should be noted that the stator modal simulation results include the stator modal frequency and the corresponding stator modal vibration mode, and the test results include the test modal frequency and the test modal vibration mode. During the comparison, the matching test modal vibration mode is searched according to the stator modal vibration mode, and then the stator modal frequency corresponding to the stator modal vibration mode is compared with the test modal frequency corresponding to the test modal vibration mode. If the deviation between the stator modal frequency and the test modal frequency exceeds the target range, the target material parameters are reassigned. Among them, the target range shown is preferably 5%, but it is not limited to this, and can be preset according to actual conditions.

[0046] The following table shows the anisotropic equivalent material parameters of the stator core obtained after iterative correction of the target material parameters of a new energy vehicle drive motor:

[0047]

[0048] S104, using the corrected target material parameters as equivalent material parameters of the stator and assigning them to the stator three-dimensional finite element model to perform stator modal simulation.

[0049] The target material parameters obtained by repeated iteration in step S103 are used as the final equivalent material parameters of the stator, and then the equivalent material parameters are assigned to the stator three-dimensional finite element model established in step S101 for stator modal simulation. Finally, the modal simulation results obtained by simulation can more accurately reflect the vibration characteristics of the actual stator.

[0050] The following table compares the modal simulation results and experimental modal results of a new energy vehicle drive motor:

[0051] Modal Simulation Results Test results Relative error Second order mode 645Hz 634Hz 1.74％ Third order mode 1781Hz 1765Hz 0.91％ Fourth mode 3179Hz 3327Hz 4.45％ Fifth mode 4617Hz 4797Hz 3.75％ Breathing Mode 5635Hz 5546Hz 1.60％

[0052] Therefore, from the comparison between the modal simulation results and the experimental modal results, it can be seen that the modal simulation results obtained by the equivalent simulation method provided by the present invention can more accurately reflect the vibration characteristics of the actual stator.

[0053] It can be seen from the above that the present invention performs accurate modal analysis on the motor stator with less workload and high simulation accuracy. The simulation results can be used for subsequent vibration noise analysis and motor structure optimization, laying a foundation for the design and optimization of the motor.

[0054] See also Figure 2 , Figure 2 The flowchart of the second embodiment of the equivalent simulation method considering the stator lamination structure of the motor of the present invention is shown, comprising:

[0055] S201, constructing a three-dimensional finite element mesh of the stator core.

[0056] It should be noted that each stator tooth of the actual stator core is the same, so the symmetry of the stator structure needs to be ensured during the finite element modeling and meshing process to reduce the error caused by structural asymmetry.

[0057] like Figure 3 As shown, the steps of constructing the three-dimensional finite element mesh of the stator core include:

[0058] (1) Construct a two-dimensional plane model of the stator teeth.

[0059] Specifically, a stator tooth two-dimensional plane model can be drawn according to the geometric parameters of the motor stator, or the stator tooth two-dimensional plane model can be cut out from a preset stator three-dimensional finite element model, wherein the stator tooth two-dimensional plane model is used to represent a two-dimensional plane model of a stator tooth.

[0060] (2) Meshing the stator tooth two-dimensional plane model to generate a stator tooth two-dimensional plane mesh.

[0061] (3) The two-dimensional plane grid of the stator teeth is arrayed in a circumferential rotation manner to generate a two-dimensional plane grid of the stator cross section.

[0062] It should be noted that after a circumferentially rotating array of a two-dimensional plane grid of a stator tooth is performed, a two-dimensional plane grid of the entire stator cross section can be obtained, thereby ensuring the grid consistency of each stator tooth.

[0063] (4) The two-dimensional plane mesh of the stator cross section is stretched along the stator axis to generate a three-dimensional finite element mesh of the stator core.

[0064] Preferably, the stretched length is equal to the axial length of the actual stator.

[0065] S202, constructing a stator winding equivalent mass point at the geometric center position of the stator core.

[0066] Considering that the actual stator winding is wound on the stator teeth, its mass is mainly distributed on the stator teeth, and the stator winding stiffness is relatively small, the impact on the motor stator mode is relatively small. In addition, in order to reduce the number of controlled variables, the present invention does not establish a physical model for the stator winding, but uses mass points instead.

[0067] In the present invention, a stator winding equivalent mass point is established at the geometric center of the stator core (i.e., the center of the cross section at the middle axial position of the stator) to store the mass of the stator winding, without establishing a solid model for the stator winding.

[0068] S203, connecting the stator winding equivalent mass point with the grid node on the surface of each stator tooth in the three-dimensional finite element grid of the iron core, so as to evenly distribute the mass of the stator winding to each stator tooth.

[0069] According to the characteristic that the actual stator winding is wound on the stator teeth, the present invention connects the equivalent mass points of the stator winding with the grid nodes on the surface of the stator teeth, thereby evenly distributing the mass of the stator winding to each stator tooth.

[0070] Therefore, unlike the prior art, the present invention does not need to separately establish a solid model of the stator winding. The mass of the stator winding is considered through equivalent mass points and its mass is evenly distributed to each stator tooth, while the stiffness of the stator winding is equivalent to the stator core. The stiffness of the actual stator assembly (stator core and stator winding) is equivalently considered by giving the stator core anisotropic materials.

[0071] S204, determining the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding.

[0072] The actual stator core is made of very thin silicon steel sheets stacked axially, but in the modeling process, it is impossible to model each silicon steel sheet separately. The entire stator core can only be modeled as a solid entity. Therefore, the stator finite element model cannot directly assign the density of the silicon steel sheet, but must assign an equivalent density. Specifically, the equivalent density of the stator core can be calculated according to the formula ρ = m / v, where ρ is the equivalent density of the stator core, m is the mass of the actual stator core, and v is the volume of the three-dimensional finite element mesh of the stator core.

[0073] Meanwhile, the mass of the actual stator winding may be used as the mass of the stator winding equivalent mass point.

[0074] For example, for a 48-slot stator of a new energy vehicle drive motor, the mass of its stator winding is 4.1kg, and the equivalent density of the stator core is 7458kg / m3, which is significantly lower than the density of silicon steel sheets (7850kg / m3).

[0075] It should be noted that after steps S201 - 204 , a complete three-dimensional finite element model of the stator can be formed for modal simulation processing.

[0076] S205, determining material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material, and using the stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency.

[0077] Specifically, the steps of determining material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material and using a stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency include:

[0078] (1) Determine the independent material parameters of the anisotropic material based on the characteristics of the stator laminated structure;

[0079] (2) assigning initial values ​​to the independent material parameters;

[0080] (3) changing the value of any independent material parameter and keeping other independent material parameters fixed, and using the stator three-dimensional finite element model to simulate and analyze the variation of the stator modal frequency with the independent material parameters;

[0081] (4) The same method is used to analyze how the stator modal frequency changes with other independent material parameters.

[0082] S206, selecting a target material parameter from the material parameters according to the influencing rule, and iteratively correcting the value of the target material parameter until the iteration is stopped when the deviation between the stator modal simulation result obtained by simulating the three-dimensional finite element model and the stator modal test result is within a target range.

[0083] Specifically, the step of iteratively correcting the value of the target material parameter until the deviation between the stator modal simulation result obtained by the three-dimensional finite element model simulation and the stator modal test result is within the target range and then stopping the iteration includes:

[0084] (1) Assigning values ​​to the target material parameters, and using the three-dimensional finite element model to perform modal simulation on the stator to generate stator modal simulation results.

[0085] (2) Compare the stator modal simulation results with the test results. If the deviation between the stator modal simulation results and the test results exceeds the target range, return to step (1) to reassign the target material parameters, and stop iterating until the deviation between the stator modal simulation results and the test results is within the target range.

[0086] S207, using the corrected target material parameters as equivalent material parameters of the stator and assigning them to the stator three-dimensional finite element model to perform stator modal simulation.

[0087] As can be seen from the above, the present invention treats the stator winding as equivalent to a mass point without establishing a physical model of the stator winding. Then, according to the characteristics of the actual stator winding wound on the stator teeth, the mass of the equivalent mass point of the stator winding is evenly distributed to each stator tooth. Then, the stator core is equivalently processed, and the stacked structure of the stator core and the stator winding is equivalently considered using anisotropic material parameters related to the stator modal simulation results. The simulation process only requires one modal test. In contrast, the existing simulation method needs to establish a physical model for the stator core and the stator winding respectively, and then determine the anisotropic material parameters of the stator core and the stator winding respectively, and perform two modal tests. That is to say, the number of anisotropic material parameters and the number of tests required to be determined by the existing simulation method are twice as many as the simulation method provided by the present invention. Therefore, the method provided by the present invention has less workload, fewer parameters to be determined, easy to control accuracy, and high simulation accuracy.

[0088] See also Figure 4 , Figure 4 The specific structure of the equivalent simulation system 100 considering the stator lamination structure of the motor according to the present invention is shown, which includes:

[0089] The model building module 1 is used to establish a three-dimensional finite element mesh of the stator core and equivalent mass points of the stator winding, and associate the three-dimensional finite element mesh of the stator core and the equivalent mass points of the stator winding to form a three-dimensional finite element model of the stator. The model building module 1 only needs to establish a solid model for the stator core, and the stator winding is equivalent to a mass point without establishing a solid model of the winding, which can greatly improve the simulation efficiency.

[0090] The law analysis module 2 is used to determine the material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material, and use the stator three-dimensional finite element model to analyze the influence of the value of the material parameters on the stator modal frequency. Specifically, the law analysis module 2 determines the independent material parameters of the 9 material parameters of the stator equivalent anisotropic material (Young's modulus in three directions, shear modulus in three planes, and three Poisson's ratios) according to the characteristics of the stator laminated structure; assigns initial values ​​to the independent material parameters; changes the value of one of the independent material parameters and keeps the other independent material parameters fixed, and uses the stator three-dimensional finite element model to simulate and analyze the change law of the stator modal frequency with the independent material parameter; finally, the same method is used to study the change law of the stator modal frequency with other independent material parameters.

[0091] The iterative correction module 3 is used to select the target material parameters from the material parameters according to the influencing law, and iteratively correct the values ​​of the target material parameters until the deviation between the stator modal simulation results obtained by the three-dimensional finite element model simulation and the stator modal test results is within the target range, and then the iteration stops. Specifically, after the iterative correction module 3 extracts the target material parameters from the material parameters according to the influencing law, it assigns values ​​to the target material parameters respectively, and then uses the three-dimensional finite element model to perform modal simulation on the stator to generate stator modal simulation results, and then compares the stator modal simulation results with the test results. If the deviation between the stator modal simulation results and the test results exceeds the target range, the target material parameters are reassigned until the deviation between the stator modal simulation results and the test results is within the target range, and then the iteration stops, thereby achieving the optimization of the value of the target material parameter.

[0092] The modal simulation module 4 is used to use the corrected target material parameters as equivalent material parameters of the stator and assign them to the stator three-dimensional finite element model to perform stator modal simulation.

[0093] Therefore, the present invention performs accurate modal analysis on the motor stator with less workload and high simulation accuracy. The simulation results can be used for subsequent vibration and noise analysis and motor structure optimization, laying a foundation for the design and optimization of the motor.

[0094] like Figure 5 As shown, the model building module 1 includes:

[0095] The mesh construction unit 11 is used to construct a three-dimensional finite element mesh of the stator core. Specifically, the mesh construction unit 11 first constructs a two-dimensional plane model of the stator teeth, then meshes the two-dimensional plane model of the stator teeth to generate a two-dimensional plane mesh of the stator teeth, then performs a circumferential rotation array on the two-dimensional plane mesh of the stator teeth to generate a two-dimensional plane mesh of the stator section, and finally stretches the two-dimensional plane mesh of the stator section along the axial direction of the stator to generate a three-dimensional finite element mesh of the stator core.

[0096] The mass point construction unit 12 is used to construct the stator winding equivalent mass point at the geometric center position of the stator core.

[0097] The association unit 13 is used to connect the stator winding equivalent mass point with the grid node on the surface of each stator tooth in the three-dimensional finite element grid of the iron core, so as to evenly distribute the mass of the stator winding to each stator tooth.

[0098] The parameter determination unit 14 is used to determine the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding. Specifically, the equivalent density of the stator core can be calculated according to the formula ρ=m / v, where ρ is the equivalent density of the stator core, m is the mass of the actual stator core, and v is the volume of the three-dimensional finite element grid of the stator core; at the same time, the mass of the actual stator winding can be used as the mass of the equivalent mass point of the stator winding.

[0099] Therefore, unlike the prior art, the present invention does not need to separately establish a solid model of the stator winding. The mass of the stator winding is considered through equivalent mass points and its mass is evenly distributed to each stator tooth, while the stiffness of the stator winding is equivalent to the stator core. The stiffness of the actual stator assembly (stator core and stator winding) is equivalently considered by giving the stator core anisotropic materials.

[0100] Accordingly, the present invention further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned equivalent simulation method when executing the computer program. At the same time, the present invention also provides a computer-readable storage medium, on which a computer program is stored, and the steps of the above-mentioned equivalent simulation method are implemented when the computer program is executed by the processor.

[0101] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An equivalent simulation method considering the stator laminated structure of a motor, characterized in that: include: Establishing a three-dimensional finite element mesh of a stator core and an equivalent mass point of a stator winding, and associating the three-dimensional finite element mesh of the stator core and the equivalent mass point of the stator winding to form a three-dimensional finite element model of the stator, the specific steps include: constructing a three-dimensional finite element mesh of the stator core; constructing an equivalent mass point of the stator winding at the geometric center position of the stator core; connecting the equivalent mass point of the stator winding with the mesh node on the surface of each stator tooth in the three-dimensional finite element mesh of the core to evenly distribute the mass of the stator winding to each stator tooth; determining the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding; Determine material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material, and use the stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency; Selecting a target material parameter from the material parameters according to the influencing law, and iteratively correcting the value of the target material parameter until the deviation between the stator modal simulation result obtained by simulating the three-dimensional finite element model and the stator modal test result is within a target range and the iteration is stopped; The corrected target material parameters are used as equivalent material parameters of the stator and assigned to the stator three-dimensional finite element model to perform stator modal simulation.

2. The equivalent simulation method according to claim 1, characterized in that: The step of constructing a three-dimensional finite element mesh of the stator core comprises: Construct a two-dimensional plane model of stator teeth; Meshing the stator tooth two-dimensional plane model to generate a stator tooth two-dimensional plane mesh; Performing a circumferential rotation array on the two-dimensional plane grid of the stator teeth to generate a two-dimensional plane grid of the stator cross section; The two-dimensional plane mesh of the stator cross section is stretched along the stator axial direction to generate a three-dimensional finite element mesh of the stator core.

3. The equivalent simulation method according to claim 2, characterized in that: The step of constructing the stator tooth two-dimensional plane model includes: drawing the stator tooth two-dimensional plane model according to the geometric parameters of the motor stator, or cutting out the stator tooth two-dimensional plane model from a preset stator three-dimensional finite element model.

4. The equivalent simulation method according to claim 1, characterized in that: The steps for determining the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding include: The equivalent density of the stator core is calculated according to the formula ρ=m / v, where ρ is the equivalent density of the stator core, m is the mass of the actual stator core, and v is the volume of the three-dimensional finite element mesh of the stator core; The mass of the actual stator winding is taken as the mass of the equivalent mass point of the stator winding.

5. The equivalent simulation method according to claim 1, characterized in that: The steps of determining material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material and using a stator three-dimensional finite element model to analyze the influence of the material parameter values ​​on the stator modal frequency include: Determine the independent material parameters of the anisotropic material according to the characteristics of the stator laminated structure; assigning initial values ​​to the independent material parameters; The value of any independent material parameter is changed while other independent material parameters are kept fixed, and the stator three-dimensional finite element model is used to simulate and analyze the variation of the stator modal frequency with the independent material parameters; The same method is used to analyze the variation of stator modal frequency with other independent material parameters.

6. The equivalent simulation method according to claim 1, characterized in that: The steps of iteratively correcting the values ​​of the target material parameters until the deviation between the stator modal simulation results obtained by the three-dimensional finite element model simulation and the stator modal test results is within the target range and stopping the iteration include: Assigning values ​​to the target material parameters, and using the three-dimensional finite element model to perform modal simulation on the stator to generate stator modal simulation results; The stator modal simulation result is compared with the test result. If the deviation between the stator modal simulation result and the test result exceeds the target range, the target material parameter is reassigned until the iteration is stopped when the deviation between the stator modal simulation result and the test result is within the target range.

7. An equivalent simulation system considering the stator stacking structure of a motor, characterized in that: include: A model building module, used to establish a three-dimensional finite element mesh of a stator core and equivalent mass points of a stator winding, and associate the three-dimensional finite element mesh of the stator core and the equivalent mass points of the stator winding to form a three-dimensional finite element model of the stator; A law analysis module, used to determine material parameters related to the stator modal simulation results according to the characteristics of the anisotropic material, and use the stator three-dimensional finite element model to analyze the influence of the values ​​of the material parameters on the stator modal frequency; an iterative correction module, used for selecting a target material parameter from the material parameters according to the influencing law, and iteratively correcting the value of the target material parameter until the deviation between the stator modal simulation result obtained by the three-dimensional finite element model simulation and the stator modal test result is within a target range and the iteration is stopped; A modal simulation module, used for taking the corrected target material parameters as equivalent material parameters of the stator and assigning them to the three-dimensional finite element model of the stator to perform stator modal simulation; The model building module includes: A mesh construction unit, used to construct a three-dimensional finite element mesh of the stator core; A mass point construction unit, used to construct an equivalent mass point of a stator winding at the geometric center position of a stator core; An association unit, used for connecting the stator winding equivalent mass point with the grid node on the surface of each stator tooth in the three-dimensional finite element grid of the iron core, so as to evenly distribute the mass of the stator winding to each stator tooth; The parameter determination unit is used to determine the equivalent density of the stator core and the mass of the equivalent mass point of the stator winding.

8. 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 method according to any one of claims 1 to 6 are implemented.

9. 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 method according to any one of claims 1 to 6 are implemented.

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