Battery pack risk assessment method and device, storage medium and computer equipment

Abstract

Embodiments of the present application provide a battery pack risk assessment method, device, storage medium and computer equipment. The method comprises: establishing a battery cell extrusion finite element numerical analysis model and performing simulation analysis; extracting a first maximum pressure value of the surface of the winding core when the battery cell is short-circuited from the simulation analysis result of the battery cell extrusion finite element numerical analysis model; establishing a battery pack extrusion finite element numerical analysis model and performing extrusion simulation analysis; extracting a second maximum pressure value of the surface of the winding core inside the battery cell from the simulation analysis result of the battery pack extrusion finite element numerical analysis model; if it is judged that the second maximum pressure value is less than the first maximum pressure value, output the battery pack. The accurate battery cell extrusion finite element numerical analysis model and the safety boundary of the battery cell extrusion internal short circuit can be obtained, the complex physical change process of the battery cell internal short circuit process is converted into a quantifiable performance index for evaluation, and the risk of the battery pack is assessed, thereby improving the accuracy and efficiency of the battery pack risk assessment.

Description

[0001] The present application relates to the technical field of battery pack, and particularly relates to a risk assessment method and device of battery pack, a storage medium and computer equipment.

[0002] As a power source of new energy vehicles, the battery pack is generally installed on the vehicle body. When a safety accident occurs, the battery pack is compressed and deformed by the vehicle. Due to the high energy characteristics of the battery pack, when the battery pack is compressed and deformed, internal short circuit occurs, the energy of the battery pack is released sharply in a short time, and the phenomenon of fire and explosion occurs, which endangers the safety of the driver and the surrounding environment.

[0003] As a core component of new energy vehicles, the safety of the battery pack is crucial to the safety of the vehicle. In the national standard GB38031-2020, the safety performance of the battery pack against compression deformation when a safety accident occurs has been required. When the battery pack is continuously compressed by a semi-cylindrical compression head with a diameter of 150mm in the driving direction or perpendicular to the driving direction, the battery pack cannot have safety risks such as liquid leakage, fire and explosion when the compression head intrusion displacement is 30% of the overall size of the battery pack in the compression direction or the compression force reaches 100KN.

[0004] The requirement of liquid leakage in the national standard is to prevent the electrolyte inside the battery cell from being exposed to the air, because the electrolyte is easy to decompose and release toxic gas when it meets the air. The requirements of fire and explosion are to prevent internal short circuit of the battery, because of the particularity of the battery pack, once the short circuit occurs, a large amount of energy will be released sharply in a short time, which is a huge threat to personal and property safety and is difficult to extinguish once it catches fire, which is easy to cause vehicle damage and casualties. In addition, according to the characteristics of the battery pack, the short circuit of the battery pack includes the short circuit of the high-voltage electrical assembly connecting the battery cells inside the battery pack and the short circuit between the pole pieces inside the battery cell. Therefore, the safety risks in the compression process of the battery pack mainly include three points: liquid leakage caused by the rupture of the battery cell shell, the short circuit of the high-voltage electrical assembly outside the battery cell, and the short circuit between the pole pieces inside the battery cell.

[0005] ​​To evaluate the safety risk of the battery pack under extrusion, the common method is to simulate and calculate the extrusion force and deformation of the battery pack under extrusion by mechanical structure finite element numerical analysis method after the battery pack is designed, to check whether the structural strength of the cell shell meets the requirements through the stress / strain distribution of the cell shell in the extrusion process, and to judge whether the cell has the risk of liquid leakage; or to measure the distance between high-voltage electrical components in the extrusion process to judge whether the external high-voltage electrical components of the cell have the risk of short circuit. However, for the short circuit between the internal pole pieces of the cell which is the carrier of the energy of the battery pack and the highest safety risk level, it cannot be identified by the finite element numerical analysis method, and only actual test means can be used to identify, which reduces the efficiency of risk assessment of the battery pack. SUMMARY

[0006] Therefore, the embodiments of the present application provide a battery pack risk assessment method, device, storage medium and computer equipment to improve the efficiency of risk assessment of the battery pack.

[0007] In one aspect, the embodiments of the present application provide a battery pack risk assessment method, comprising:

[0008] establishing a cell extrusion finite element numerical analysis model and performing simulation analysis;

[0009] extracting a first maximum pressure value of the surface of the wound core when the cell is short-circuited from the simulation analysis result of the cell extrusion finite element numerical analysis model;

[0010] establishing a battery pack extrusion finite element numerical analysis model and performing simulation analysis, the battery pack extrusion finite element numerical analysis model comprising the cell extrusion finite element numerical analysis model;

[0011] extracting a second maximum pressure value of the surface of the wound core inside the cell from the simulation analysis result of the battery pack extrusion finite element numerical analysis model;

[0012] judging whether the second maximum pressure value is less than the first maximum pressure value;

[0013] if it is judged that the second maximum pressure value is less than the first maximum pressure value, outputting the battery pack.

[0014] Optionally, before the establishing a cell extrusion finite element numerical analysis model and performing simulation analysis, comprising:

[0015] performing a cell-level extrusion test on the cell of the battery pack according to a test load condition to obtain a first force-displacement curve in the extrusion process of the cell.

[0016] Optionally, the first maximum pressure value of the winding core surface in the short circuit of the battery cell is extracted from the simulation analysis result of the finite element numerical analysis of the battery cell extrusion, comprising:

[0017] A test load condition is applied to the finite element numerical analysis model of the battery cell extrusion, and a second force-displacement curve of the battery cell extrusion is extracted from the simulation analysis result;

[0018] It is judged whether the first force-displacement curve and the second force-displacement curve are the same;

[0019] If it is judged that the first force-displacement curve and the second force-displacement curve are the same, a first change curve is obtained from the numerical simulation analysis result of the battery cell extrusion, the first change curve being a curve of the pressure of the winding core surface varying with the extrusion force or displacement in the extrusion process of the battery cell;

[0020] The force or displacement of the battery cell in the short circuit is substituted into the first change curve to generate the first maximum pressure value of the winding core surface in the short circuit of the battery cell.

[0021] Optionally, before the second maximum pressure value of the winding core surface in the battery cell is extracted from the simulation analysis result of the finite element numerical analysis model of the battery pack extrusion, the method further comprises:

[0022] The test load condition is applied to the finite element numerical analysis model of the battery pack extrusion, and a second change curve is obtained from the simulation analysis result of the finite element numerical analysis software, the second change curve being a curve of the maximum pressure of the battery cell surface varying with the extrusion force or displacement;

[0023] According to the simulation analysis result of the battery pack extrusion to the cutoff condition, it is judged whether there is a risk in the battery pack;

[0024] If it is judged that there is no risk in the battery pack, the step of extracting the second maximum pressure value of the winding core surface in the battery cell from the simulation analysis result of the finite element numerical analysis model of the battery pack extrusion is continued.

[0025] Optionally, the method further comprises:

[0026] If it is judged that the first force-displacement curve and the second force-displacement curve are not the same, the mechanical property parameters of the winding core in the battery cell are adjusted, and the step of establishing the finite element numerical analysis model of the battery cell extrusion and performing simulation analysis is continued.

[0027] Optionally, the method further comprises:

[0028] If it is judged that there is a risk inside the battery pack, the performance parameters of the battery pack are adjusted, and the step of establishing the battery pack extrusion finite element numerical analysis model and performing simulation analysis is continued.

[0029] Optionally, the method further comprises:

[0030] If it is judged that the second maximum pressure value is greater than or equal to the first maximum pressure value, the performance parameters of the battery pack are adjusted, and the step of establishing the battery pack extrusion finite element numerical analysis model and performing simulation analysis is continued.

[0031] In another aspect, an embodiment of the present application provides a risk assessment device for a battery pack, comprising:

[0032] A first establishing module is configured to establish a cell extrusion finite element numerical analysis model and perform simulation analysis.

[0033] A first extracting module is configured to extract a first maximum pressure value of a winding core surface when there is a short circuit in a cell from a simulation analysis result of the cell extrusion finite element numerical analysis model.

[0034] A second establishing module is configured to establish a battery pack extrusion finite element numerical analysis model and perform simulation analysis, wherein the battery pack extrusion finite element numerical analysis model comprises the cell extrusion finite element numerical analysis model.

[0035] A second extracting module is configured to extract a second maximum pressure value of a winding core surface inside a cell from a simulation analysis result of the battery pack extrusion finite element numerical analysis model.

[0036] A first judging module is configured to judge whether the second maximum pressure value is less than the first maximum pressure value. If it is judged that the second maximum pressure value is less than the first maximum pressure value, an output module is triggered to output the battery pack.

[0037] In another aspect, an embodiment of the present application provides a storage medium, comprising a stored program, wherein the program controls a device in which the storage medium is located to perform the risk assessment method for a battery pack when the program is running.

[0038] In another aspect, an embodiment of the present application provides a computer device, comprising a memory and a processor, wherein the memory is configured to store information comprising program instructions, and the processor is configured to control the execution of the program instructions, and the program instructions are loaded and executed by the processor to implement the steps of the risk assessment method for a battery pack.

[0039] The technical scheme of the risk assessment method of the battery pack provided by the embodiment of the present application comprises the following steps: a cell extrusion finite element numerical analysis model is established and simulated; a first maximum pressure value of a winding core surface when an internal short circuit occurs in the cell is extracted from the simulation analysis result of the cell extrusion finite element numerical analysis model; a battery pack extrusion finite element numerical analysis model is established and simulated; a second maximum pressure value of the winding core surface inside the cell is extracted from the simulation analysis result of the battery pack extrusion finite element numerical analysis model; and if it is judged that the second maximum pressure value is less than the first maximum pressure value, the battery pack is output. The accurate cell extrusion finite element numerical analysis model and the safety boundary of the internal short circuit of the cell extrusion are obtained, the complex physical change process of the internal short circuit process of the cell is converted into a quantifiable performance index for evaluation, and the risk assessment of the battery pack is performed, thereby improving the accuracy and efficiency of the risk assessment of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0041] Figure 1 The flowchart of the risk assessment method of the battery pack provided by the embodiment of the present application;

[0042] Figure 2 The flowchart of another risk assessment method of the battery pack provided by the embodiment of the present application;

[0043] Figure 3 The structural schematic diagram of the risk assessment device of the battery pack provided by the embodiment of the present application;

[0044] Figure 4 The structural schematic diagram of the first extraction module in the embodiment of the present application; Figure 3

[0045] Figure 5 The schematic diagram of the computer device provided by the embodiment of the present application.

DETAILED DESCRIPTION

[0046] In order to better understand the technical scheme of the present application, the embodiments of the present application will be described in detail below with reference to the drawings.

[0047] It should be clear that the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] ​The terminology used in the description of the embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting thereof. As used in the description of the embodiments and the appended claims herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0049] It should be understood that the term "and / or" as used herein merely describes associated objects in association, which means that there can be three relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0050] The embodiments of the present application provide a battery pack risk assessment method, Figure 1 A flowchart of the battery pack risk assessment method provided by the embodiments of the present application is shown in Figure 1 The method comprises the following steps:

[0051] In step 102, a cell extrusion finite element numerical analysis model is established and simulated.

[0052] In the embodiments of the present application, each step is executed by a computer device. For example, the computer device includes a computer or a tablet computer.

[0053] In this step, the cell extrusion finite element numerical analysis model can be a single cell extrusion finite element numerical analysis model.

[0054] In this step, the cell extrusion finite element numerical analysis model can be established according to the extrusion test of the cell level.

[0055] In step 104, a first maximum pressure value of the winding core surface when the cell is short-circuited is extracted from the simulation analysis result of the cell extrusion finite element numerical analysis model.

[0056] In the embodiments of the present application, the first maximum pressure value of the winding core surface when the cell is short-circuited is a safety boundary value of the cell extrusion.

[0057] In step 106, a battery pack extrusion finite element numerical analysis model is established and simulated, and the battery pack extrusion finite element numerical analysis model contains the cell extrusion finite element numerical analysis model.

[0058] In step 108, a second maximum pressure value of the winding core surface inside the cell is extracted from the simulation analysis result of the battery pack extrusion finite element numerical analysis model.

[0059] In the embodiments of the present application, the second maximum pressure value of the winding core surface inside the cell is the maximum pressure value of the winding core surface inside the cell when the battery pack is extruded to the cutoff condition.

[0060] In the embodiment of the present application, the cutoff condition is that the extrusion force reaches 100KN or the extrusion displacement reaches 30% of the overall size of the battery pack in the extrusion direction.

[0061] Step 110: determining whether the second maximum pressure value is less than the first maximum pressure value.

[0062] In the embodiment of the present application, if it is determined that the second maximum pressure value is less than the first maximum pressure value, it indicates that there is no risk of internal short circuit of the battery pack during the extrusion process; if it is determined that the second maximum pressure value is greater than or equal to the first maximum pressure value, it indicates that there is a risk of internal short circuit of the battery pack during the extrusion process.

[0063] Step 112: outputting the battery pack if it is determined that the second maximum pressure value is less than the first maximum pressure value.

[0064] As an optional solution, if there is no risk of internal short circuit of the battery pack during the extrusion process, the battery pack can be optimized for weight reduction, lightweighting, etc. The optimized battery pack needs to be evaluated and confirmed according to steps 102-112, and then the optimized battery pack is outputted for subsequent sample making and testing.

[0065] In the technical solution provided by the embodiment of the present application, the cell extrusion finite element numerical analysis model is established and simulated, the first maximum pressure value of the cell surface when the internal short circuit occurs is extracted from the simulation analysis result of the cell extrusion finite element numerical analysis model, the battery pack extrusion finite element numerical analysis model is established and simulated, the second maximum pressure value of the internal cell surface is extracted from the simulation analysis result of the battery pack extrusion finite element numerical analysis model, and the battery pack is outputted if it is determined that the second maximum pressure value is less than the first maximum pressure value. The accurate cell extrusion finite element numerical analysis model and the safety boundary of the cell extrusion internal short circuit are obtained, the complex physical change process of the cell internal short circuit process is converted into a quantifiable performance index for risk evaluation of the battery pack, and the accuracy and efficiency of the risk evaluation of the battery pack are improved.

[0066] The embodiment of the present application provides another risk evaluation method for a battery pack, Figure 2 The flowchart of the another risk evaluation method for a battery pack provided by the embodiment of the present application is shown in Figure 2 The method comprises the following steps:

[0067] Step 202: performing an extrusion test on the cell of the battery pack at the cell level according to a test load condition to obtain a first force-displacement curve in the cell extrusion process.

[0068] In the embodiment of the present application, each step is executed by a computer device. For example, the computer device comprises a computer or a tablet computer.

[0069] In the embodiment of the present application, the test load condition includes a fixed constraint condition and a load condition. For example, the fixed constraint condition is room temperature 20℃, and the load condition is 100KN.

[0070] In this step, the cell layer extrusion test is performed on the battery cell according to the test load condition. The voltage, temperature and first force-displacement curve of the cell are monitored during the test, and the force and displacement when the cell short-circuits are recorded. Wherein, the voltage drop or temperature rise of the cell means that the internal short-circuit of the cell begins to occur.

[0071] Step 204, establishing a cell extrusion finite element numerical analysis model and performing simulation analysis.

[0072] In this step, the cell extrusion finite element numerical analysis model can be established according to the cell layer extrusion test.

[0073] Step 206, applying the test load condition in the cell extrusion finite element numerical analysis model, and extracting the second force-displacement curve of the cell extrusion in the simulation analysis result.

[0074] Step 208, judging whether the first force-displacement curve and the second force-displacement curve are the same, if yes, executing step 210; if no, executing step 226.

[0075] In the embodiment of the present application, if it is judged that the first force-displacement curve and the second force-displacement curve are the same, it means that the cell extrusion finite element numerical analysis model is accurate, and step 210 is executed; if it is judged that the first force-displacement curve and the second force-displacement curve are not the same, it means that the cell extrusion finite element numerical analysis model is not accurate, and step 226 is executed.

[0076] Step 210, obtaining the first change curve from the simulation analysis result of the cell extrusion finite element numerical analysis model, the first change curve being a curve of the pressure on the surface of the cell core changing with the extrusion force or displacement during the cell extrusion process.

[0077] Step 212, substituting the force or displacement when the cell short-circuits in the first force-displacement curve into the first change curve to generate the first maximum pressure value on the surface of the cell core when the cell short-circuits.

[0078] In the embodiment of the present application, the first maximum pressure value on the surface of the cell core when the cell short-circuits is the safety boundary value when the cell extrusion does not occur internal short-circuit.

[0079] Step 214, establishing a battery pack extrusion finite element numerical analysis model and performing simulation analysis, the battery pack extrusion finite element numerical analysis model including the cell extrusion finite element numerical analysis model.

[0080] Step 216, a test load condition is applied to the battery pack extrusion finite element numerical analysis model, and a second change curve is extracted from the simulation analysis result, the second change curve being a curve of the maximum pressure on the surface of the cell changing with the extrusion force or displacement.

[0081] Step 218, whether there is a risk inside the battery pack is determined according to the simulation analysis result when the battery pack is extruded to the cutoff condition, if yes, step 228 is executed, and if no, step 220 is executed.

[0082] In this step, the risks inside the battery pack include a battery pack leakage risk and / or a high-voltage lap joint risk.

[0083] In the embodiment of the application, the cutoff condition is that the extrusion force reaches 100 KN or the extrusion displacement reaches 30% of the overall size of the battery pack in the extrusion direction.

[0084] For example, the simulation analysis result of the battery pack includes the distance between high-voltage electrical components, the creepage distance, the stress and strain of the cell shell, etc.

[0085] In the embodiment of the application, for example, whether the distance between high-voltage electrical components meets the requirements of electrical clearance, creepage distance, etc., whether the stress and strain of the cell shell are within the strength range of the shell material, so as to determine whether the high-voltage electrical components inside the battery pack exist lap joint short circuit and whether the cell shell exists a risk of rupture and leakage when the battery pack is extruded to the cutoff condition, if there is a risk, step 228 is executed, and if there is no risk, step 220 is executed.

[0086] Step 220, a second maximum pressure value on the surface of the cell inside the cell is extracted from the simulation analysis result of the battery pack extrusion finite element numerical analysis model.

[0087] Step 222, whether the second maximum pressure value is less than the first maximum pressure value is determined, if yes, step 224 is executed, and if no, step 228 is executed.

[0088] In the embodiment of the application, if it is determined that the second maximum pressure value is less than the first maximum pressure value, it indicates that there is no risk of internal short circuit of the cell inside the battery pack during the extrusion process, and step 224 is executed, and if it is determined that the second maximum pressure value is greater than or equal to the first maximum pressure value, it indicates that there is a risk of internal short circuit of the cell inside the battery pack during the extrusion process, and step 228 is executed.

[0089] Step 224, the battery pack is output, and the process ends.

[0090] As an alternative, if the battery pack does not have the risk of internal short circuit of the cell inside during the extrusion process, the battery pack can be optimized for weight reduction, lightweighting, and other cost reduction. The optimized battery pack needs to be evaluated and confirmed according to steps 202-228, and then the optimized battery pack is output for subsequent sample testing.

[0091] Step 226, adjust the mechanical property parameters of the cell internal winding core, and perform step 204.

[0092] Step 228, adjust the performance parameters of the battery pack, and perform step 214.

[0093] Specifically, the performance parameters of the battery pack are adjusted by increasing protection, structural reinforcement, and other optimizations.

[0094] In the technical scheme provided by the embodiment of the application, the cell extrusion finite element numerical analysis model is established and simulated, the first maximum pressure value of the winding core surface when the cell is short-circuited is extracted from the simulation analysis result of the cell extrusion finite element numerical analysis model, the battery pack extrusion finite element numerical analysis model is established and simulated, the second maximum pressure value of the winding core surface inside the cell is extracted from the simulation analysis result of the battery pack extrusion finite element numerical analysis model, and the battery pack is output if it is judged that the second maximum pressure value is less than the first maximum pressure value. The accurate cell extrusion finite element numerical analysis model and the safety boundary of the cell extrusion internal short circuit can be obtained, the complex physical change process of the cell internal short circuit process is converted into a quantifiable performance index for risk assessment of the battery pack, and the accuracy and efficiency of the risk assessment of the battery pack are improved.

[0095] In the technical scheme provided by the embodiment of the application, the risk of internal short circuit of the cell inside during the extrusion process of the battery pack level can be accurately identified, and the blank that cannot be evaluated by theoretical analysis is filled.

[0096] In the technical scheme provided by the embodiment of the application, based on the finite element numerical analysis, repeated test tests are not needed, the cycle is short, the cost is low, and different design schemes can be quickly verified.

[0097] In the technical scheme provided by the embodiment of the application, the internal changes during the extrusion process of the battery pack can be observed and the key parameter index can be extracted, the key parameters of the quantitative design are provided, and the key guidance significance for weight reduction, lightweighting, cost reduction, and scheme optimization of the battery pack is provided.

[0098] The embodiment of the application provides a risk assessment device for a battery pack. Figure 3 The structure diagram of the risk assessment device for the battery pack provided by the embodiment of the application is shown in Figure 3As shown, the device comprises a first establishing module 11, a first extracting module 12, a second establishing module 13, a second extracting module 14, a first judging module 15 and an output module 16.

[0099] The first establishing module 11 is configured to establish a battery cell extrusion finite element numerical analysis model and perform simulation analysis.

[0100] The first extracting module 12 is configured to extract a first maximum pressure value of a winding core surface when a short circuit occurs in the battery cell from the simulation analysis result of the battery cell extrusion finite element numerical analysis model.

[0101] The second establishing module 13 is configured to establish a battery pack extrusion finite element numerical analysis model and perform simulation analysis, wherein the battery pack extrusion finite element numerical analysis model comprises the battery cell extrusion finite element numerical analysis model.

[0102] The second extracting module 14 is configured to extract a second maximum pressure value of a winding core surface inside the battery cell from the simulation analysis result of the battery pack extrusion finite element numerical analysis model.

[0103] The first judging module 15 is configured to judge whether the second maximum pressure value is less than the first maximum pressure value; if it is judged that the second maximum pressure value is less than the first maximum pressure value, the output module 16 is triggered to output the battery pack.

[0104] In the embodiment of the application, the device further comprises a first obtaining module 17.

[0105] The first obtaining module 17 is configured to perform an extrusion test on the battery cell of the battery pack at a battery cell level according to a test load condition, and obtain a first force-displacement curve in the extrusion process of the battery cell.

[0106] In the embodiment of the application, Figure 4 For Figure 3 The structural diagram of the first extracting module is shown in FIG. 2. Figure 4 As shown, the first extracting module 12 comprises an extracting submodule 121, a judging submodule 122, an obtaining submodule 123 and a generating submodule 124.

[0107] The extracting submodule 121 is configured to apply a test load condition in the battery cell extrusion finite element numerical analysis model, and extract a second force-displacement curve of the battery cell extrusion in the simulation analysis result.

[0108] The judging submodule 122 is configured to judge whether the first force-displacement curve and the second force-displacement curve are the same; if it is judged that the first force-displacement curve and the second force-displacement curve are the same, the obtaining submodule 123 is triggered to obtain a first change curve from the simulation analysis result of the battery cell extrusion finite element numerical analysis model, wherein the first change curve is a curve of the pressure of the winding core surface varying with the extrusion force or displacement in the extrusion process of the battery cell.

[0109] The generating sub-module 124 is configured to substitute the force or displacement of the short circuit in the cell in the first force-displacement curve into the first change curve to generate a first maximum pressure value of the surface of the winding core in the short circuit in the cell.

[0110] In the embodiment of the present application, the device further comprises a third extracting module 18 and a second judging module 19.

[0111] The third extracting module 18 is configured to apply the test load condition to the finite element numerical analysis model of the battery pack extrusion, and extract a second change curve from the simulation analysis result, wherein the second change curve is a curve of the maximum pressure of the surface of the cell changing with the extrusion force or displacement.

[0112] The second judging module 19 is configured to determine whether there is a risk inside the battery pack according to the simulation analysis result when the battery pack is extruded to the cutoff condition; if it is determined that there is no risk inside the battery pack, the second extracting module 14 is triggered to continue the step of extracting the second maximum pressure value of the surface of the winding core in the cell from the simulation analysis result of the finite element numerical analysis model of the battery pack extrusion.

[0113] In the embodiment of the present application, the device further comprises a first adjusting module 20.

[0114] The judging sub-module 122 is configured to trigger the first adjusting module 20 to adjust the mechanical property parameter of the winding core in the cell if it is determined that the first force-displacement curve and the second force-displacement curve are different, and trigger the first establishing module 11 to continue the step of establishing the finite element numerical analysis model of the cell extrusion and performing simulation analysis.

[0115] In the embodiment of the present application, the device further comprises a second adjusting module 21.

[0116] The second judging module 19 is configured to trigger the second adjusting module 21 to adjust the performance parameter of the battery pack if it is determined that there is a risk inside the battery pack, and trigger the second establishing module 13 to continue the step of establishing the finite element numerical analysis model of the battery pack extrusion and performing simulation analysis.

[0117] In the embodiment of the present application, the first judging module 15 is configured to trigger the second adjusting module 21 to adjust the performance parameter of the battery pack if it is determined that the second maximum pressure value is greater than the first maximum pressure value, and trigger the second establishing module 13 to continue the step of establishing the finite element numerical analysis model of the battery pack extrusion and performing simulation analysis.

[0118] The technical solution provided in this invention involves establishing a finite element numerical analysis model for cell extrusion and performing simulation analysis; extracting the first maximum pressure value on the surface of the core during an internal short circuit in the cell from the simulation analysis results of the finite element numerical analysis model for cell extrusion; establishing a finite element numerical analysis model for battery pack extrusion and performing extrusion simulation analysis; extracting the second maximum pressure value on the surface of the core inside the cell from the simulation analysis results of the finite element numerical analysis model for battery pack extrusion; and outputting the battery pack if the second maximum pressure value is determined to be less than the first maximum pressure value. This approach enables the acquisition of an accurate finite element numerical analysis model for cell extrusion and the safety boundary for an internal short circuit during cell extrusion, transforming the complex physical changes of the internal short circuit process into quantifiable performance indicators for battery pack risk assessment, thereby improving the accuracy and efficiency of battery pack risk assessment.

[0119] The battery pack risk assessment device provided in this embodiment can be used to achieve the above. Figure 1 and Figure 2 The risk assessment method for the battery pack is described in detail in the embodiments of the above-mentioned risk assessment method for the battery pack, and will not be repeated here.

[0120] This invention provides a storage medium that includes a stored program. When the program runs, it controls the device where the storage medium is located to execute the steps of the above-described risk assessment method for a battery pack. For a detailed description, please refer to the embodiments of the above-described risk assessment method for a battery pack.

[0121] This invention provides a computer device including a memory and a processor. The memory stores information including program instructions, and the processor controls the execution of the program instructions. When the program instructions are loaded and executed by the processor, they implement the steps of the above-described battery pack risk assessment method. For a detailed description, please refer to the above-described battery pack risk assessment method embodiments.

[0122] Figure 5 This is a schematic diagram of a computer device provided in an embodiment of the present invention. Figure 5 As shown, the computer device 50 of this embodiment includes a processor 51, a memory 52, and a computer program 53 stored in the memory 52 and executable on the processor 51. When the computer program 53 is executed by the processor 51, it implements the risk assessment method for the battery pack in this embodiment. To avoid repetition, it will not be described in detail here. Alternatively, when the computer program is executed by the processor 51, it implements the functions of each model / unit in the risk assessment device for the battery pack in this embodiment. To avoid repetition, it will not be described in detail here.

[0123] Computer device 50 includes, but is not limited to, processor 51 and memory 52. ​​Those skilled in the art will understand that... Figure 5The computer device 50 is only an example and does not constitute a limitation on the computer device 50, which can include more or fewer components than shown, or combine some components, or have different components, for example, the computer device can also include an input / output device, a network access device, a bus, etc.

[0124] The processor 51 can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0125] The memory 52 can be an internal storage unit of the computer device 50, for example, a hard disk or a memory of the computer device 50. The memory 52 can also be an external storage device of the computer device 50, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 52 can include both the internal storage unit and the external storage device of the computer device 50. The memory 52 is used to store computer programs and other programs and data required by the computer device. The memory 52 can also be used to temporarily store data that has been output or will be output.

[0126] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0127] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be implemented by other means. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or components shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0128] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e., may be located in one place, or may be distributed to multiple network units. Part or all of the units may be selected according to actual needs to achieve the purpose of the embodiment.

[0129] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of hardware plus software functional unit.

[0130] The integrated unit realized in the form of software functional unit can be stored in a computer readable storage medium. The software functional unit stored in a storage medium includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes a variety of storage media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0131] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A risk assessment method for a battery pack, characterized in that, The method comprises the following steps: establishing a finite element numerical analysis model of cell extrusion and performing simulation analysis; extracting a first maximum pressure value of the cell core surface when the cell is short-circuited from the simulation analysis result of the finite element numerical analysis model of cell extrusion; establishing a finite element numerical analysis model of battery pack extrusion and performing simulation analysis, wherein the finite element numerical analysis model of battery pack extrusion comprises the finite element numerical analysis model of cell extrusion; extracting a second maximum pressure value of the cell core surface inside the cell from the simulation analysis result of the finite element numerical analysis model of battery pack extrusion; determining whether the second maximum pressure value is less than the first maximum pressure value; if it is determined that the second maximum pressure value is less than the first maximum pressure value, outputting the battery pack; Before the step of establishing the finite element numerical analysis model of cell extrusion and performing simulation analysis, the method further comprises the following steps: performing cell-level extrusion test on the cell of the battery pack according to the test load condition to obtain a first force-displacement curve in the cell extrusion process; The step of extracting the first maximum pressure value of the cell core surface when the cell is short-circuited from the simulation analysis result of the finite element numerical analysis model of cell extrusion comprises the following steps: applying the test load condition to the finite element numerical analysis model of cell extrusion, and extracting a second force-displacement curve of cell extrusion from the simulation analysis result; determining whether the first force-displacement curve and the second force-displacement curve are the same; if it is determined that the first force-displacement curve and the second force-displacement curve are the same, obtaining a first change curve from the simulation analysis result of the finite element numerical analysis model of cell extrusion, wherein the first change curve is a curve of the pressure of the cell core surface varying with the extrusion force or displacement in the cell extrusion process; substituting the force or displacement of the cell when short-circuited in the first force-displacement curve into the first change curve to generate the first maximum pressure value of the cell core surface when the cell is short-circuited.

2. The method of claim 1, wherein, After the step of establishing the finite element numerical analysis model of battery pack extrusion and performing simulation analysis, and before the step of extracting the second maximum pressure value of the cell core surface inside the cell from the simulation analysis result of the finite element numerical analysis model of battery pack extrusion, the method further comprises the following steps: applying the test load condition to the finite element numerical analysis model of battery pack extrusion, and extracting a second change curve from the simulation analysis result, wherein the second change curve is a curve of the maximum pressure of the cell surface varying with the extrusion force or displacement; determining whether there is a risk inside the battery pack according to the simulation analysis result when the battery pack is extruded to the cutoff condition; if it is determined that there is no risk inside the battery pack, continuing to perform the step of extracting the second maximum pressure value of the cell core surface inside the cell from the simulation analysis result of the finite element numerical analysis model of battery pack extrusion.

3. The method of claim 1, wherein, The method further comprises the following steps: if it is determined that the first force-displacement curve and the second force-displacement curve are not the same, adjusting the mechanical property parameters of the cell core inside the cell, and continuing to perform the step of establishing the finite element numerical analysis model of cell extrusion and performing simulation analysis.

4. The method of claim 2, wherein, The method further comprises the following steps: if it is determined that there is a risk inside the battery pack, adjusting the performance parameters of the battery pack, and continuing to perform the step of establishing the finite element numerical analysis model of battery pack extrusion and performing simulation analysis.

5. The method of claim 1, wherein, The method further comprises the following steps: If it is judged that the second maximum pressure value is greater than or equal to the first maximum pressure value, the performance parameter of the battery pack is adjusted, and the step of establishing a battery pack extrusion finite element numerical analysis model and performing simulation analysis is continued. 6.A risk assessment device of a battery pack, characterized by, Comprise: The first establishment module is used for establishing a cell extrusion finite element numerical analysis model and performing simulation analysis. The first extraction module is used for extracting a first maximum pressure value of a winding core surface when a cell internal short circuit occurs from a simulation analysis result of the cell extrusion finite element numerical analysis model. The second establishment module is used for establishing a battery pack extrusion finite element numerical analysis model and performing simulation analysis, and the battery pack extrusion finite element numerical analysis model contains the cell extrusion finite element numerical analysis model. The second extraction module is used for extracting a second maximum pressure value of a winding core surface inside a cell from a simulation analysis result of a battery pack extrusion finite element numerical analysis model. The first judgment module is used for judging whether the second maximum pressure value is less than the first maximum pressure value; if it is judged that the second maximum pressure value is less than the first maximum pressure value, the output module is triggered to output the battery pack. The first acquisition module is used for performing a cell-level extrusion test on a cell of a battery pack according to a test load condition, and acquiring a first force-displacement curve in a cell extrusion process. The first extraction module comprises an extraction submodule, a judgment submodule, an acquisition submodule and a generation submodule. The extraction submodule is used for applying a test load condition in the cell extrusion finite element numerical analysis model, and extracting a second force-displacement curve of cell extrusion in a simulation analysis result. The judgment submodule is used for judging whether the first force-displacement curve and the second force-displacement curve are the same; if it is judged that the first force-displacement curve and the second force-displacement curve are the same, the acquisition submodule is triggered to acquire a first change curve from a simulation analysis result of the cell extrusion finite element numerical analysis model, and the first change curve is a curve of a pressure of a winding core surface varying with extrusion force or displacement in a cell extrusion process. The generation submodule is used for substituting a force or displacement when a cell internal short circuit occurs in the first force-displacement curve into the first change curve, and generating a first maximum pressure value of a winding core surface when a cell internal short circuit occurs.

7. A storage medium, characterized by The storage medium comprises a stored program, wherein when the program runs, the device where the storage medium is located performs the risk assessment method of the battery pack in any one of claims 1 to 5.

8. A computer device comprising a memory for storing information including program instructions, and a processor for controlling execution of the program instructions, characterized in that, The program instructions are loaded and executed by the processor to realize the steps of the risk assessment method of the battery pack in any one of claims 1 to 5.

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