Battery pack homogenization simulation modeling method

Abstract

The invention provides a battery pack homogenization simulation modeling method, which comprises the following steps of: performing earlier-stage processing on a three-dimensional model of a battery pack and a battery monomer and a roll core in the battery pack to obtain a finite element model of the battery pack and the battery monomer and the roll core in the battery pack; the results of the plane compression test and the single-axis quasi-dynamic and static tensile test of the single battery and the roll core are subjected to benchmarking with the plane compression simulation results and the single-axis quasi-dynamic and static tensile simulation results of the single battery finite element model and the roll core finite element model; optimizing the finite element models of the single battery and the roll core, respectively obtaining the optimal finite element models of the single battery and the roll core, and importing the optimal finite element models into the battery pack simulation model to form a battery pack simplified model; performing benchmarking on the test result of the battery pack safety test and the simulation result of the safety test of the battery pack simplified model; the battery pack simplification model is optimized, the optimal battery pack simplification model is obtained, the number of calculation units of the battery pack simplification model is reduced, the simulation calculation time of the battery pack simplification model is shortened, and the simulation calculation efficiency of the battery pack simplification model is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile batteries, and in particular to a battery pack homogenization simulation modeling method. Background Art

[0002] Electric vehicles are developing rapidly, but they also have many safety issues. In an electric vehicle collision accident, the battery may be damaged under the action of mechanical loads, leading to thermal runaway of the battery. Therefore, the safety performance of the battery pack needs to be simulated before the product is launched on the market to verify the battery pack's ability to withstand loads. In existing battery pack simulation tests, detailed modeling of the battery pack is generally used to calculate and verify the safety performance of the battery pack. This modeling method is relatively complex, takes a long time to perform simulation calculations, and has low calculation efficiency. Therefore, in order to improve the efficiency of the battery pack simulation calculation, the battery pack model needs to be simplified to improve the efficiency of the battery pack simulation calculation while being able to perform overall calculations of the battery pack. Summary of the invention

[0003] One of the purposes of the present invention is to provide a battery pack homogenization simulation modeling method to solve the problem of low calculation efficiency caused by using a refined modeling method to simulate the battery pack in the prior art, so as to improve the efficiency of the battery pack simulation calculation.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A battery pack homogenization simulation modeling method includes the following steps:

[0006] S1. Pre-processing the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model to obtain a battery pack finite element model, a battery cell finite element model and a winding core finite element model respectively;

[0007] S2. Benchmark the plane compression test results of the battery cell and the winding core, and the uniaxial quasi-dynamic and static tensile test results of the battery cell and the winding core with the corresponding simulation results;

[0008] S3, feedback and optimize the battery cell finite element model and the winding core finite element model according to the benchmarking result, to obtain an optimal battery cell finite element model and an optimal winding core finite element model;

[0009] S4, importing the optimal battery cell finite element model and the optimal winding core finite element model into the battery pack finite element model to form a simplified battery pack model;

[0010] S5. Benchmarking the test results of the battery pack safety test with the safety test simulation results of the simplified model of the battery pack;

[0011] S6. Feedback the benchmarking results and optimize the simplified battery pack model to obtain the optimal simplified battery pack model.

[0012] According to the above technical means, a battery pack finite element model and a battery cell finite element model and a winding core finite element model inside the battery pack three-dimensional model are established, and the plane compression simulation results of the battery cell finite element model and the winding core finite element model are benchmarked and optimized with the plane compression test results of the battery cell and the winding core, which can make the mechanical performance simulation accuracy of the battery cell finite element model and the winding core finite element model higher; then, the optimal battery cell finite element model and the winding core finite element model are imported into the battery pack simulation model to establish a simplified model of the battery pack, and the simplified battery pack model is benchmarked and optimized through a battery pack safety test, so that the safety test simulation calculation results of the simplified battery pack model have a high degree of overlap with the test results of the battery pack safety test, and can better reflect the mechanical properties of the battery pack, while greatly reducing the complexity of the model, shortening the simulation calculation time of the simplified battery pack model, improving the efficiency of the simulation calculation, and further improving the efficiency of battery pack research and development.

[0013] Furthermore, the preliminary processing specifically includes the following sub-steps:

[0014] S11, performing contour cleaning processing on the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model;

[0015] S12, performing contour optimization processing on the cleaned battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model;

[0016] S13, performing finite element meshing on the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model to obtain a battery pack finite element model, a battery cell finite element model and a winding core finite element model.

[0017] According to the above technical means, grid division is performed to subdivide the battery pack three-dimensional model and the battery cell three-dimensional model and the core three-dimensional model inside the battery pack three-dimensional model into multiple small units, so that simulation analysis can be carried out on a finer scale to reflect the simulation calculation results more realistically.

[0018] Furthermore, the contour cleaning process specifically includes the following steps: deleting the battery pack three-dimensional model and the complex local structures in the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model.

[0019] According to the above technical means, the redundant parts and unnecessary details that have little impact on the overall calculation results are removed, so that the contours of the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model can be made smoother and more regular.

[0020] Furthermore, the contour optimization processing specifically includes the following steps: deleting the repeated symmetrical parts in the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model; performing axisymmetric and / or mirror-symmetrical processing on the axisymmetric and / or mirror-symmetrical parts to obtain a complete shape.

[0021] According to the above technical means, deleting repeated symmetrical components reduces the amount of data of the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model, making the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model more concise and clear, and convenient for meshing; at the same time, the symmetrical components are symmetrically processed, reducing the errors that may be caused by manual drawing or modification, and improving the accuracy and reliability of the overall design.

[0022] Furthermore, the plane compression test result is obtained by the following steps:

[0023] The battery extrusion tester performs axial and radial compression tests on the battery cell and the winding core to obtain the force-displacement curve of the battery cell and the force-displacement curve of the winding core under the plane compression test conditions, respectively.

[0024] Furthermore, the uniaxial quasi-dynamic and static tensile test results are obtained by the following steps:

[0025] The high-speed tensile testing machine performs uniaxial quasi-dynamic tensile tests in the axial and radial directions on the material slices of the battery cells and the winding core, so as to obtain the stress-strain curves of the battery cell materials and the stress-strain curves of the winding core materials under the uniaxial quasi-dynamic tensile test conditions, respectively; the material universal testing machine performs uniaxial quasi-static tensile tests in the axial and radial directions on the material slices of the battery cells and the winding core, so as to obtain the stress-strain curves of the battery cell materials and the stress-strain curves of the winding core materials under the uniaxial quasi-static tensile test conditions, respectively.

[0026] According to the above technical means, the force-displacement curve and stress-strain curve of the battery cell and the core under the conditions of plane compression test and uniaxial quasi-dynamic and static test are obtained, and the data of the force-displacement curve and the stress-strain curve are sorted, so as to further obtain the mechanical property parameters of the battery cell material and the core material, so as to calibrate the simulation results of the battery cell finite element model and the core finite element model under the conditions of plane compression test and uniaxial quasi-dynamic and static test, and optimize the material parameters of the battery cell finite element model and the core finite element model.

[0027] Furthermore, the S3 step includes the following sub-steps:

[0028] S31, feeding back the benchmarking results of the battery cell finite element model and the winding core finite element model to the optimization unit of the simulation software;

[0029] S32. The optimization unit adjusts material parameters of the battery cell finite element model and the winding core finite element model according to the feedback result to obtain an optimal battery cell finite element model and an optimal winding core finite element model, respectively.

[0030] According to the above technical means, the optimization unit optimizes the material parameters of the battery cell finite element model and the winding core finite element model, which can make the simulation calculation results of the battery cell finite element model and the winding core finite element model closer to the actual test results.

[0031] Furthermore, the simplified battery pack model is established by the following steps:

[0032] The optimal battery cell finite element model and the optimal winding core finite element model are imported into the battery pack finite element model, and the optimal battery cell finite element model and the optimal winding core finite element model are simplified into an equivalent block model divided by a quadrilateral solid unit grid to form a simplified battery pack model.

[0033] According to the above technical means, the battery cell finite element model and the winding core finite element model are simplified into an equivalent block model, which reduces the number of units in the simplified battery pack model, shortens the simulation calculation time of the simplified battery pack model, and improves the simulation calculation efficiency.

[0034] Furthermore, the step S6 includes the following sub-steps:

[0035] S61, feeding back the benchmarking result of the simplified battery pack model to the optimization unit of the simulation software;

[0036] S62. The optimization unit adjusts the material parameters of the simplified battery pack model according to the feedback result to obtain the optimal simplified battery pack model.

[0037] According to the above technical means, the optimization unit optimizes the material parameters of the simplified model of the battery pack, so that the simulation calculation results of the simplified model of the battery pack are closer to the actual test results.

[0038] Furthermore, the method further comprises the following steps:

[0039] S7. Importing the optimal simplified battery pack model into the whole vehicle finite element model, simplifying the optimal simplified battery pack model into a battery pack replacement model divided by quadrilateral shell unit meshes, so as to form a simplified model of the whole vehicle.

[0040] According to the above technical means, the simplified battery pack model is simplified into a battery pack replacement model in the whole vehicle test. The outline dimensions of the battery pack replacement model are consistent with the outline dimensions of the simplified battery pack model, and only shell unit meshing is used for simulation modeling to reflect the outer contour of the battery pack. A mass point is added to the geometric center of the battery pack replacement model to simulate the counterweight of the battery pack, which reduces the calculation units of the simplified model of the whole vehicle, shortens the simulation calculation time of the simplified model of the whole vehicle, and improves the efficiency of the simulation calculation.

[0041] The beneficial effects of the present invention are:

[0042] By establishing a battery pack finite element model and a battery cell finite element model and a roll core finite element model inside the battery pack three-dimensional model, the plane compression simulation results of the battery cell finite element model and the roll core finite element model are benchmarked and optimized with the plane compression test results of the battery cell and the roll core, which can make the mechanical performance simulation accuracy of the battery cell finite element model and the roll core finite element model higher; then the optimal battery cell finite element model and the roll core finite element model are imported into the battery pack simulation model to establish a simplified battery pack model, and the simplified battery pack model is benchmarked and optimized through a battery pack safety test, so that the safety test simulation calculation results of the simplified battery pack model have a high degree of overlap with the test results of the battery pack safety test, and can better reflect the mechanical properties of the battery pack, while greatly reducing the complexity of the model, shortening the simulation calculation time of the simplified battery pack model, improving the efficiency of the simulation calculation, and further improving the efficiency of battery pack research and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 is a flow chart of the battery pack homogenization simulation modeling method provided by the present invention;

[0045] Figure 2 is a sub-step flow chart of step S1 in the present invention;

[0046] Figure 3 is a sub-step flow chart of step S3 in the present invention;

[0047] Figure 4 It is a sub-step flow chart of step S6 in the present invention. DETAILED DESCRIPTION

[0048] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. The accompanying drawings are only used for exemplary description and cannot be understood as limiting the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0049] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0050] like Figures 1 to 4 As shown, this embodiment provides a battery pack homogenization simulation modeling method, comprising the following steps:

[0051] S1. Pre-process the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model to obtain a battery pack finite element model, a battery cell finite element model and a winding core finite element model respectively;

[0052] S2. Benchmark the plane compression test results of the battery cell and the winding core with the plane compression simulation results of the battery cell finite element model and the winding core finite element model; benchmark the uniaxial quasi-dynamic and static tensile test results of the battery cell and the winding core with the uniaxial quasi-dynamic and static tensile simulation results of the battery cell finite element model and the winding core finite element model;

[0053] S3. Feedback and optimize the battery cell finite element model and the winding core finite element model based on the benchmarking results to obtain the optimal battery cell finite element model and the optimal winding core finite element model;

[0054] S4, importing the optimal battery cell finite element model and the optimal winding core finite element model into the battery pack finite element model to form a simplified battery pack model;

[0055] S5. Benchmark the test results of the battery pack safety test with the safety test simulation results of the simplified model of the battery pack;

[0056] S6. Feedback the benchmark results and optimize the simplified battery pack model to obtain the optimal simplified battery pack model.

[0057] By establishing a battery pack finite element model, a battery cell finite element model and a winding core finite element model, and benchmarking and optimizing the plane compression simulation results of the battery cell finite element model and the winding core finite element model with the plane compression test results of the battery cell and the winding core, the mechanical performance simulation accuracy of the battery cell finite element model and the winding core finite element model can be higher; then, the optimal battery cell finite element model and the winding core finite element model are imported into the battery pack simulation model to establish a simplified battery pack model, and the simplified battery pack model is benchmarked and optimized through a battery pack safety test, so that the safety test simulation calculation results of the simplified battery pack model have a high degree of overlap with the test results of the battery pack safety test, and can better reflect the mechanical properties of the battery pack under various working conditions, while greatly reducing the complexity of the model, shortening the simulation calculation time of the simplified battery pack model, improving the efficiency of the simulation calculation, and further improving the efficiency of battery pack research and development.

[0058] like Figure 2 As shown, in this embodiment, the preliminary processing specifically includes the following sub-steps:

[0059] S11, performing contour cleaning processing on the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model;

[0060] S12, performing contour optimization processing on the cleaned battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model;

[0061] S13, performing finite element meshing on the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model to obtain the battery pack finite element model, the battery cell finite element model and the winding core finite element model.

[0062] The battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model are meshed and subdivided into multiple small units, so that the simulation analysis can be carried out on a finer scale to truly reflect the simulation calculation results.

[0063] In this embodiment, the contour cleaning process specifically includes the following steps: deleting the complex local structures in the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model.

[0064] By removing redundant parts and unnecessary details that have little impact on the overall calculation results, such as process holes with smaller diameters, transition fillets or chamfers, smaller bosses on the overlapping edges, etc., the contours of the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model can be made smoother and more regular, which is conducive to meshing the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model.

[0065] In this embodiment, the contour optimization process specifically includes the following steps: deleting repeated symmetrical components in the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model;

[0066] Perform axisymmetric and / or mirror-symmetrical processing on axisymmetric and / or mirror-symmetrical parts to obtain the complete shape.

[0067] Deleting repeated symmetrical parts reduces the amount of data for the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model, making the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model more concise and clear, and facilitating meshing; at the same time, symmetrical parts are processed symmetrically, reducing errors that may be caused by manual drawing or modification, and improving the accuracy and reliability of the overall design.

[0068] In this embodiment, when performing finite element mesh division on the battery pack three-dimensional model and the battery cell three-dimensional model and the roll core three-dimensional model inside the battery pack three-dimensional model, it is necessary to adjust the generation quality of the finite element mesh respectively through geometric processing of bodies, surfaces, lines, points and the density of boundary nodes in local areas. The finite element mesh should fit the contours of the battery pack three-dimensional model and the battery cell three-dimensional model and the roll core three-dimensional model inside the battery pack three-dimensional model as much as possible, with uniform density distribution and the flow direction consistent with the contours of the above three-dimensional models. After obtaining the battery pack finite element model, the battery cell finite element model and the roll core finite element model, it is also necessary to control the quality of the finite element mesh. The parameters of the finite element mesh include the minimum and maximum size of the unit, the side length ratio, the warp, the minimum and maximum internal angles, the slope, the Jacobian and the triangle ratio; finally, it is necessary to check the repeated nodes and units, free edges, unit continuity, unit normal consistency, etc., in order to adjust the parameters of the mesh unit.

[0069] In this embodiment, the plane compression test results are obtained by the following steps:

[0070] The battery extrusion tester performs axial and radial compression tests on the battery cells and the winding core to obtain the force-displacement curve of the battery cells and the force-displacement curve of the winding core under the plane compression test conditions respectively; the loading speed of the battery extrusion tester should be at least 5m / s.

[0071] When conducting axial and radial compression tests on battery cells and cores, select some battery cells and cores, and use a battery extrusion testing machine to conduct at least three axial and radial compression tests on the battery cells and cores to obtain force-displacement curves. It is required that the force-bearing surfaces of the cells and cores are uniform, and no obvious displacement occurs during the compression process.

[0072] When simulating the plane compression process of the battery cell finite element model and the winding core finite element model, the same boundary conditions as the plane compression test are added on the basis of the battery cell finite element model and the winding core finite element model, including the disc and support plate of the battery extrusion tester. The disc and the support plate are defined as rigid bodies, and all degrees of freedom of the support plate are restricted. The disc only retains the displacement degrees of freedom in the direction perpendicular to the surface of the disc. In addition to adding the same boundary conditions as the plane compression test, the connection relationship between different components in the battery pack needs to be added, including: the contact relationship between the battery cell, the metal end plate, the metal side plate, the plastic cover plate, and the busbar. Surface contact is adopted between different components, among which the battery cell and the busbar are connected by constrained rigid bodies according to the actual welding area; the metal end plate and the metal side plate are welded, and the binding relationship between the shell unit and the surface is used for equivalent treatment; the plastic cover plate and the metal side plate are snap-connected, and the rigid body constraint connection setting is used in the model.

[0073] In this embodiment, the uniaxial quasi-dynamic and static tensile test results are obtained by the following steps:

[0074] The high-speed tensile testing machine performs uniaxial quasi-dynamic tensile tests on the material slices of the battery cell and the core in the axial and radial directions, so as to obtain the stress-strain curves of the battery cell material and the stress-strain curves of the core material under the uniaxial quasi-dynamic tensile test conditions respectively; the high-speed tensile testing machine should allow a maximum loading of 20m / s to meet the wide strain rate test range of up to 1000 / s, and be equipped with piezoelectric sensors / lightweight sensors to reduce the load oscillation problem during dynamic loading.

[0075] The universal material testing machine performs uniaxial quasi-static tensile tests on the material slices of the battery cell and the core in the axial and radial directions to obtain the stress-strain curves of the battery cell material and the stress-strain curves of the core material under the uniaxial quasi-static tensile test conditions. The universal material testing machine should ensure that the relative error of the test force indication and the beam displacement indication is not higher than ±0.5%, and the relative error of the beam speed should be within ±0.5% of the set value. The loading speed of the uniaxial quasi-static tensile test should be set to 2mm / min or a quasi-static tensile speed.

[0076] When performing uniaxial quasi-dynamic and static tensile tests on the material slices of the battery cell and the winding core in the axial and radial directions, rectangular samples that are easy to perform uniaxial tensile tests are cut out on the relatively flat surfaces of the battery cell and the winding core for uniaxial quasi-dynamic and static tensile tests. When performing uniaxial quasi-static tensile tests, the strain rate is 0.001s -1 At least three tests were conducted under the conditions to obtain the stress-strain curve under the uniaxial quasi-static tensile test conditions. When conducting the uniaxial quasi-dynamic tensile test, the strain rate was 0.01s -1 , 0.1s -1 , 10s -1 , 100s -1 , 500s -1 At least three tests were conducted under the conditions to obtain the stress-strain curve under the uniaxial quasi-dynamic tensile test conditions. The stress-strain curves under the uniaxial quasi-static tensile test and the uniaxial quasi-dynamic tensile test conditions were imported into the material constitutive equation of the simulation software to reflect the material properties of the battery cell simulation model and the battery cell simulation model; the Johson-Cook dynamic constitutive equation was used in this embodiment.

[0077] According to the uniaxial quasi-dynamic and static tensile test, the force-displacement curves and stress-strain curves of the battery cell and the core under the conditions of plane compression test and uniaxial quasi-dynamic and static test are obtained, and the mechanical performance parameters of the battery cell material and the core material can be further obtained, so as to calibrate the simulation results of the battery cell finite element model and the core finite element model under the conditions of plane compression test and uniaxial quasi-dynamic and static test and optimize the material parameters.

[0078] like Figure 3 As shown, in this embodiment, step S3 includes the following sub-steps:

[0079] S31, the benchmarking results of the battery cell finite element model and the winding core finite element model are fed back to the optimization unit of the simulation software;

[0080] S32. The optimization unit adjusts the material parameters of the battery cell finite element model and the winding core finite element model according to the feedback result to obtain the optimal battery cell finite element model and the optimal winding core finite element model respectively.

[0081] The optimization unit adjusts the material parameters of the battery cell finite element model and the winding core finite element model, including: material stiffness, counterweight, etc. In addition to optimizing the material parameters, it can also optimize the connection between the components of the battery cell finite element model and the winding core finite element model. After the parameters are adjusted, the battery cell finite element model and the winding core finite element model are simulated again. When the coincidence between the simulation calculation results and the actual test results is less than 80%, the optimization unit adjusts the parameters again until the coincidence between the simulation calculation results of the battery cell finite element model and the winding core finite element model and the actual test results is not less than 80%, so that the simulation calculation results of the battery cell finite element model and the winding core finite element model are closer to the actual test results.

[0082] In this embodiment, the simplified battery pack model is established by the following steps:

[0083] The optimal battery cell finite element model and the optimal winding core finite element model are imported into the battery pack finite element model. The optimal battery cell finite element model and the optimal winding core finite element model are simplified into an equivalent block model divided by a quadrilateral solid unit mesh to form a simplified battery pack model.

[0084] The battery cell finite element model and the winding core finite element model are simplified into an equivalent block model. The equivalent block model does not distinguish between the multiple winding cores inside the battery cell and the battery cell shell, and only uses solid unit grids for representation, reducing the number of units in the simplified battery pack model to shorten the calculation time of the simplified battery pack model and improve the calculation efficiency. It is worth mentioning that the solid unit grid size of the equivalent block model is 8mm.

[0085] like Figure 4 As shown, in this embodiment, step S6 includes the following sub-steps:

[0086] S61. The benchmarking result of the simplified model of the battery pack is fed back to the optimization unit of the simulation software;

[0087] S62. The optimization unit adjusts the material parameters of the simplified battery pack model according to the feedback results to obtain the optimal simplified battery pack model.

[0088] The optimization unit optimizes the material parameters of the simplified battery pack model, including the stiffness and weight of the material. In addition to optimizing the material parameters, it can also optimize the connection between the components of the simplified battery pack model. The simplified battery pack model after parameter adjustment needs to be simulated again. When the coincidence between the simulation calculation results and the actual test results is less than 80%, the optimization unit adjusts the parameters again until the coincidence between the simulation calculation results and the actual test results is not less than 80%, so that the simulation calculation results of the simplified battery pack model are closer to the actual test results.

[0089] like Figure 1 As shown, in this embodiment, the battery pack homogenization simulation modeling method further includes the following steps:

[0090] S7. Import the optimal battery pack simplified model into the whole vehicle finite element model, and simplify the optimal battery pack simplified model into a battery pack replacement model divided by quadrilateral shell unit mesh to form a simplified model of the whole vehicle.

[0091] In the vehicle test, the simplified battery pack model is simplified into a battery pack replacement model. The outline size of the battery pack replacement model is consistent with the outline size of the simplified battery pack model, and only shell unit meshing is used for simulation modeling to reflect the outline of the battery pack. A mass point is added to the geometric center of the battery pack replacement model to simulate the weight of the battery pack, which reduces the calculation unit of the simplified vehicle model, shortens the simulation calculation time of the simplified vehicle model, and improves the efficiency of the simulation calculation. It is worth mentioning that the shell unit mesh size in the battery pack replacement model is 8mm.

[0092] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery pack homogenization simulation modeling method, characterized in that: The following steps are involved: S1. Pre-processing the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model to obtain a battery pack finite element model, a battery cell finite element model and a winding core finite element model respectively; S2. Benchmark the plane compression test results of the battery cell and the winding core, and the uniaxial quasi-dynamic and static tensile test results of the battery cell and the winding core with the corresponding simulation results; S3, feedback and optimize the battery cell finite element model and the winding core finite element model according to the benchmarking result, to obtain an optimal battery cell finite element model and an optimal winding core finite element model; S4, importing the optimal battery cell finite element model and the optimal winding core finite element model into the battery pack finite element model to form a simplified battery pack model; S5. Benchmarking the test results of the battery pack safety test with the safety test simulation results of the simplified model of the battery pack; S6. Feedback the benchmarking results and optimize the simplified battery pack model to obtain the optimal simplified battery pack model.

2. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The preliminary processing specifically includes the following sub-steps: S11, performing contour cleaning processing on the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model; S12, performing contour optimization processing on the cleaned battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model; S13, performing finite element meshing on the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model to obtain a battery pack finite element model, a battery cell finite element model and a winding core finite element model.

3. The battery pack homogenization simulation modeling method according to claim 2, characterized in that: The outline cleaning process specifically comprises the following steps: The complex local structures in the battery pack 3D model and the battery cell 3D model and the winding core 3D model inside the battery pack 3D model are deleted.

4. The battery pack homogenization simulation modeling method according to claim 2, characterized in that: The contour optimization process specifically comprises the following steps: Deleting repeated symmetrical components in the battery pack three-dimensional model and the battery cell three-dimensional model and the winding core three-dimensional model inside the battery pack three-dimensional model; Perform axisymmetric and / or mirror-symmetrical processing on axisymmetric and / or mirror-symmetrical parts to obtain the complete shape.

5. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The plane compression test results are obtained by the following steps: The battery extrusion tester performs axial and radial compression tests on the battery cell and the winding core to obtain the force-displacement curve of the battery cell and the force-displacement curve of the winding core under the plane compression test conditions, respectively.

6. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The uniaxial quasi-dynamic and static tensile test results are obtained by the following steps: The high-speed tensile testing machine performs uniaxial quasi-dynamic tensile tests on the material slices of the battery cell and the winding core in the axial and radial directions, so as to obtain the stress-strain curves of the battery cell material and the stress-strain curves of the winding core material under the uniaxial quasi-dynamic tensile test conditions respectively; The material universal testing machine performs uniaxial quasi-static tensile tests on the material slices of the battery cell and the core in the axial and radial directions to obtain the stress-strain curves of the battery cell material and the stress-strain curves of the core material under the uniaxial quasi-static tensile test conditions, respectively.

7. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The S3 step includes the following sub-steps: S31, feeding back the benchmarking results of the battery cell finite element model and the winding core finite element model to the optimization unit of the simulation software; S32. The optimization unit adjusts material parameters of the battery cell finite element model and the winding core finite element model according to the feedback result to obtain an optimal battery cell finite element model and an optimal winding core finite element model, respectively.

8. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The simplified battery pack model is established by the following steps: The optimal battery cell finite element model and the optimal winding core finite element model are imported into the battery pack finite element model, and the optimal battery cell finite element model and the optimal winding core finite element model are simplified into an equivalent block model divided by a quadrilateral solid unit grid to form a simplified battery pack model.

9. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The S6 step includes the following sub-steps: S61, feeding back the benchmarking result of the simplified battery pack model to the optimization unit of the simulation software; S62. The optimization unit adjusts the material parameters of the simplified battery pack model according to the feedback result to obtain the optimal simplified battery pack model.

10. The battery pack homogenization simulation modeling method according to claim 1, characterized in that: The following steps are also included: S7. Importing the optimal simplified battery pack model into the whole vehicle finite element model, simplifying the optimal simplified battery pack model into a battery pack replacement model divided by quadrilateral shell unit meshes, so as to form a simplified model of the whole vehicle.

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