Method and system for determining load spectrum of power battery

Abstract

The invention provides a load spectrum determination method and system for a power battery, and relates to the technical field of new energy automobiles. The load spectrum determination method of the power battery comprises the following steps: testing a to-be-determined power battery based on an electric vehicle road load spectrum, and obtaining preset point location vibration data of the to-be-determined power battery; establishing a power battery flexible body model of the to-be-determined power battery; generating a power battery load spectrum virtual iteration model based on the power battery flexible body model; and performing virtual iterative calculation based on the preset point location vibration data and the power battery load spectrum virtual iterative model to obtain load spectrum data of the to-be-determined power battery. The method for determining the load spectrum of the power battery can achieve the technical effect of improving the accuracy of the load spectrum of the power battery.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a method and system for determining a load spectrum of a power battery. Background Art

[0002] At present, the electrochemical characteristics of battery packs are dangerous, and the load conditions are very complex, which puts higher requirements on the structural reliability of battery packs. However, it is difficult to directly obtain the load spectrum of battery packs through actual measurement methods, and conventional load spectra are generally used for vibration fatigue analysis. The load spectrum of the battery is closely related to the design of the vehicle. Using a single standard load spectrum for calculation often leads to over-design and failure to meet the requirements of lightweighting.

[0003] In the prior art, a single standard, conventional battery pack load spectrum is usually used for vibration fatigue analysis. However, the current conventional load spectrum does not reflect the differences in vibration reduction designs of different vehicles, and the load spectrum does not reflect the differences in vehicle weight and battery pack weight. In addition, the indifferent analysis of the load spectrum often leads to over-design of the structural strength of some battery packs, which cannot reduce the design cost and control the weight of the battery pack, and cannot provide accurate load spectrum input for structural fatigue analysis of the battery pack. Summary of the invention

[0004] The purpose of the present application is to provide a method, system, electronic device and computer-readable storage medium for determining a load spectrum of a power battery, which can achieve the technical effect of improving the accuracy of the load spectrum of the power battery.

[0005] In a first aspect, the present application provides a method for determining a load spectrum of a power battery, comprising:

[0006] Testing the power battery to be determined based on the road load spectrum of the electric vehicle to obtain vibration data of preset points of the power battery to be determined;

[0007] Establishing a power battery flexible body model of the power battery to be determined;

[0008] Generate a power battery load spectrum virtual iteration model based on the power battery flexible body model;

[0009] A virtual iterative calculation is performed based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined.

[0010] In the above implementation process, the power battery to be determined is tested based on the road load spectrum of the electric vehicle, the vibration data of the preset points are obtained, and the virtual iterative model of the power battery load spectrum is generated based on the power battery flexible body model; thereby, the virtual iterative calculation of the power battery load spectrum virtual iterative model is performed with the preset point vibration data as the iteration target, and the convergence of the iterative calculation is verified by comparing the response signal with the preset point vibration data, and finally the load spectrum of the power battery to be determined at any position can be calculated, that is, the load spectrum data of the power battery to be determined is obtained; thereby, the load spectrum determination method of the power battery can solve the inaccuracy of vibration fatigue analysis using conventional load spectra and the possible over-design problems, and achieve the technical effect of improving the accuracy of the power battery load spectrum.

[0011] Furthermore, the step of establishing a power battery flexible body model of the power battery to be determined includes:

[0012] Acquiring a power battery geometric model of the power battery to be determined;

[0013] Finite element processing is performed based on the power battery geometric model, and meshing and modal calculation are performed on the power battery geometric model to obtain a power battery flexible body model, wherein the power battery flexible body model reserves corresponding connection points when meshing, and the power battery flexible body model is connected to the vehicle body equivalent model through the connection points.

[0014] Furthermore, the step of generating a virtual iterative model of a power battery load spectrum based on the power battery flexible body model includes:

[0015] Establish multi-channel virtual test bench model and vehicle body equivalent model;

[0016] Based on the vehicle body equivalent model and the power battery flexible body model, a vehicle body-battery pack rigid-flexible coupling multi-body dynamics model is generated;

[0017] Based on the vehicle body-battery pack rigid-flexible coupled multi-body dynamics model and the multi-channel virtual test bench model, a virtual iterative model of the power battery load spectrum is generated, wherein the multi-channel virtual test bench model serves as an excitation source to provide displacement excitation and acceleration excitation to the vehicle body equivalent model; the power battery flexible body model serves as a response object, and under the excitation generated by the excitation source, the response object generates a displacement response and an acceleration response.

[0018] In the above implementation process, the power battery flexible body model and the multi-channel virtual test bench model are modeled separately, and then combined through the vehicle body equivalent model to obtain the virtual iterative model of the power battery load spectrum; wherein, the multi-channel virtual test bench model applies the excitation load to the vehicle body equivalent model, and through the connection between the vehicle body equivalent model and the power battery flexible body model, the excitation load is transferred from the vehicle body equivalent model to the power battery flexible body model; it should be noted that the virtual iterative model of the battery pack load spectrum needs to verify whether the center of mass position, mass, moment of inertia, etc. of each model component and assembly such as the vehicle body equivalent model and the power battery flexible body model are consistent with the actual model.

[0019] Furthermore, the step of performing virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined includes:

[0020] Iteratively calculating the power battery load spectrum virtual iterative model based on a preset multi-body dynamics model to obtain response signal data;

[0021] Obtaining relative loss value data based on the response signal data and the preset point vibration data;

[0022] If the relative loss value data is within a preset threshold range, the load spectrum data of the power battery to be determined is generated according to the response signal data.

[0023] In the above implementation process, the vibration data of the preset point is used as the iteration target, and the relative loss value data is calculated based on the response signal data and the vibration data of the preset point; if the relative loss value data is within the preset threshold range, the response signal data meets the convergence requirements, and then the load spectrum data of the power battery to be determined is generated based on the response signal data.

[0024] Furthermore, the step of generating the load spectrum data of the power battery to be determined according to the response signal data includes:

[0025] Generate a response transfer function of the power battery load spectrum virtual iterative model based on the response signal data;

[0026] The load spectrum data of the power battery to be determined is obtained based on the response transfer function.

[0027] Furthermore, the step of testing the power battery to be determined based on the road load spectrum of the electric vehicle and obtaining the vibration data of the preset points of the power battery to be determined includes:

[0028] Obtaining road load spectrum of electric vehicles;

[0029] The road load spectrum of the electric vehicle is input into a load spectrum bench test device to obtain the preset point vibration data of the power battery, wherein the power battery to be determined is installed in the electric vehicle based on the preset installation point, and the electric vehicle is set on the load spectrum bench test device.

[0030] In the above implementation process, the road load spectrum of the electric vehicle can be an actually collected road load spectrum of the electric vehicle; thus, the road load spectrum collected from the actual vehicle is input into the load spectrum bench test device, and the load test is performed on the power battery to be determined by the load spectrum bench test device to obtain the preset point vibration data of the power battery; further, the preset point vibration data is used as the virtual iteration target, so as to further improve the accuracy of the power battery load spectrum.

[0031] In a second aspect, the present application provides a load spectrum determination system for a power battery, comprising:

[0032] A testing module, used to test the power battery to be determined based on the road load spectrum of the electric vehicle, and obtain vibration data of preset points of the power battery to be determined;

[0033] A battery flexible body module, used to establish a power battery flexible body model of the power battery to be determined;

[0034] A virtual iteration module, used for generating a virtual iteration model of a power battery load spectrum based on the power battery flexible body model;

[0035] The load spectrum determination module is used to perform virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined.

[0036] Furthermore, the battery flexible body module is specifically used for:

[0037] Acquiring a power battery geometric model of the power battery to be determined;

[0038] Finite element processing is performed based on the power battery geometric model, and meshing and modal calculation are performed on the power battery geometric model to obtain a power battery flexible body model, wherein the power battery flexible body model reserves corresponding connection points when meshing, and the power battery flexible body model is connected to the vehicle body equivalent model through the connection points.

[0039] Furthermore, the virtual iteration module is specifically used for:

[0040] Establish multi-channel virtual test bench model and vehicle body equivalent model;

[0041] Based on the vehicle body equivalent model and the power battery flexible body model, a vehicle body-battery pack rigid-flexible coupling multi-body dynamics model is generated;

[0042] Based on the vehicle body-battery pack rigid-flexible coupled multi-body dynamics model and the multi-channel virtual test bench model, a virtual iterative model of the power battery load spectrum is generated, wherein the multi-channel virtual test bench model serves as an excitation source to provide displacement excitation and acceleration excitation to the vehicle body equivalent model; the power battery flexible body model serves as a response object, and under the excitation generated by the excitation source, the response object generates a displacement response and an acceleration response.

[0043] Furthermore, the load spectrum determination module is specifically used for:

[0044] Iteratively calculating the power battery load spectrum virtual iterative model based on a preset multi-body dynamics model to obtain response signal data;

[0045] Obtaining relative loss value data based on the response signal data and the preset point vibration data;

[0046] If the relative loss value data is within a preset threshold range, the load spectrum data of the power battery to be determined is generated according to the response signal data.

[0047] Furthermore, the load spectrum determination module is also used for:

[0048] The step of generating the load spectrum data of the power battery to be determined according to the response signal data comprises:

[0049] Generate a response transfer function of the power battery load spectrum virtual iterative model based on the response signal data;

[0050] The load spectrum data of the power battery to be determined is obtained based on the response transfer function.

[0051] Furthermore, the test module is specifically used for:

[0052] Obtaining road load spectrum of electric vehicles;

[0053] The road load spectrum of the electric vehicle is input into a load spectrum bench test device to obtain the preset point vibration data of the power battery, wherein the power battery to be determined is installed in the electric vehicle based on the preset installation point, and the electric vehicle is set on the load spectrum bench test device.

[0054] In a third aspect, the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in any one of the first aspects when executing the computer program.

[0055] In a fourth aspect, the present application provides a computer-readable storage medium, on which instructions are stored. When the instructions are executed on a computer, the computer executes the method as described in any one of the first aspects.

[0056] In a fifth aspect, the present application provides a computer program product, which, when running on a computer, enables the computer to execute the method as described in any one of the first aspects.

[0057] Other features and advantages disclosed in the present application will be described in the following description, or some features and advantages can be inferred or determined without doubt from the description, or can be learned by implementing the above-mentioned technology disclosed in the present application.

[0058] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 A schematic flow chart of a method for determining a load spectrum of a power battery provided in an embodiment of the present application;

[0061] Figure 2 A schematic flow chart of another method for determining a load spectrum of a power battery provided in an embodiment of the present application;

[0062] Figure 3 A structural block diagram of a load spectrum determination system for a power battery provided in an embodiment of the present application;

[0063] Figure 4 A structural block diagram of an electronic device provided in an embodiment of the present application;

[0064] Figure 5 A schematic diagram of the relationship between the number of iterations and the relative loss value provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0066] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0067] Generally, electric vehicles pursue lightweight and high power density, and further require battery packs to have high energy density and small size. The electrochemical characteristics of battery packs determine that battery packs are inevitably highly dangerous. At the same time, the vehicle operating conditions are complex and the load conditions are very complex, which puts higher requirements on the structural reliability of battery packs (power batteries). The power battery system is one of the core systems of electric vehicles. The good structural mechanical properties of power batteries are the basis for the safety and reliability of electric vehicles. The safety issues of power batteries also restrict the development of the new energy vehicle industry. Conventional analysis of power batteries, such as spectrum analysis and vibration analysis, often has certain discrepancies with actual working conditions and cannot truly reflect the actual stress and vibration conditions of power batteries. Blind pursuit of safety over-design will lead to the inability to achieve accurate lightweight analysis, and the test cycle of power batteries is long and the cost is high. It is very important to obtain the load spectrum of power batteries through power battery virtual testing.

[0068] In order to solve the above-mentioned technical problems, the embodiments of the present application provide a method, system, electronic device and computer-readable storage medium for determining a load spectrum of a power battery, which can be applied to the process of determining the load spectrum of any point of the power battery; see Figure 1 , Figure 1 A schematic flow chart of a method for determining a load spectrum of a power battery provided in an embodiment of the present application, wherein the method for determining a load spectrum of a power battery comprises the following steps:

[0069] S100: testing the power battery to be determined based on the road load spectrum of the electric vehicle, and obtaining vibration data of preset points of the power battery to be determined;

[0070] Exemplarily, the road load spectrum of the electric vehicle in the embodiment of the present application may be a road load spectrum of the electric vehicle obtained through actual collection;

[0071] In some embodiments, the test device for testing the power battery to be determined can be a twenty-four-channel acceleration vibration test bench; the electric vehicle to be tested is placed on the twenty-four-channel acceleration vibration test bench, so that the vibration data of the preset position of the power battery pack used by the electric vehicle under comprehensive cycle road conditions or other actual road conditions (i.e., preset point vibration data) is obtained through the twenty-four-channel acceleration vibration test bench, so that the preset point vibration data is used as the target of virtual iteration.

[0072] Optionally, in the embodiment of the present application, the vibration data of the preset point includes acceleration data, and may also include displacement data, velocity data, etc.; it should be noted that this is only an example and not a limitation.

[0073] S200: Establishing a power battery flexible body model of the power battery to be determined;

[0074] Exemplarily, the flexible body model of the battery pack can be calculated by finite element software based on the geometric model of the power battery; wherein, the flexible body of the battery pack needs to be connected to the vehicle body, and corresponding connection points are reserved when the geometric model of the power battery is meshed, and the geometric model of the power battery is connected to the equivalent model of the vehicle body through the connection points.

[0075] S300: generating a virtual iteration model of a power battery load spectrum based on a power battery flexible body model;

[0076] Exemplarily, after obtaining the power battery flexible body model, a corresponding power battery load spectrum virtual iterative model is generated; wherein the power battery load spectrum virtual iterative model includes an excitation source, through which vibration excitation (vibration excitation includes displacement excitation, acceleration excitation, etc.) is provided to the power battery flexible body model, and then the response data of the power battery flexible body model to the vibration excitation is obtained through the multi-body dynamics model.

[0077] S400: Perform virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined.

[0078] Exemplarily, taking the vibration data of preset points as the target, by performing virtual iterative calculations on the virtual iterative model of the power battery load spectrum, the response data of the power battery flexible body model to vibration excitation can be obtained, and then the response transfer function of the power battery to be determined to vibration excitation can be obtained; thus, based on the response transfer function, the load spectrum of any position of the power battery to be determined can be obtained, and the load spectrum data of the determined power battery can be generated.

[0079] In some embodiments, the method for determining the load spectrum of a power battery provided in an embodiment of the present application tests the power battery to be determined based on the road load spectrum of an electric vehicle, obtains vibration data at preset points, and generates a virtual iterative model of the power battery load spectrum based on the power battery flexible body model; thereby, taking the vibration data at preset points as the iteration target, the virtual iterative calculation of the power battery load spectrum virtual iterative model is performed, and the convergence of the iterative calculation is verified by comparing the response signal with the vibration data at preset points, and finally the load spectrum of the power battery to be determined at any position can be calculated, that is, the load spectrum data of the power battery to be determined is obtained; thereby, the method for determining the load spectrum of the power battery can solve the inaccuracy of vibration fatigue analysis using conventional load spectra and the possible over-design problems, and achieve the technical effect of improving the accuracy of the power battery load spectrum.

[0080] See also Figure 2 , Figure 2 A schematic flow chart of another method for determining a load spectrum of a power battery provided in an embodiment of the present application.

[0081] Exemplarily, S200: the step of establishing a power battery flexible body model of the power battery to be determined includes:

[0082] S210: Obtaining a power battery geometric model of the power battery to be determined;

[0083] S220: Perform finite element processing based on the power battery geometric model, and perform meshing and modal calculation on the power battery geometric model to obtain a power battery flexible body model, wherein the power battery flexible body model reserves corresponding connection points when meshing, and the power battery flexible body model is connected to the vehicle body equivalent model through the connection points.

[0084] Exemplarily, S300: the step of generating a virtual iterative model of a power battery load spectrum based on a power battery flexible body model includes:

[0085] S310: Establish a multi-channel virtual test bench model and a vehicle body equivalent model;

[0086] S320: Generate a rigid-flexible coupling multi-body dynamics model of the vehicle body and battery pack based on the vehicle body equivalent model and the power battery flexible body model;

[0087] S330: Generate a virtual iterative model of the power battery load spectrum based on the rigid-flexible coupling multi-body dynamics model of the vehicle body and battery pack and the multi-channel virtual test bench model. The multi-channel virtual test bench model serves as an excitation source to provide displacement excitation and acceleration excitation to the vehicle body equivalent model. The power battery flexible body model serves as a response object. Under the excitation generated by the excitation source, the response object generates a displacement response and an acceleration response.

[0088] Exemplarily, the power battery flexible body model and the multi-channel virtual test bench model are modeled separately, and then combined through the vehicle body equivalent model to obtain a virtual iterative model of the power battery load spectrum; wherein the multi-channel virtual test bench model applies an excitation load to the vehicle body equivalent model, and through the connection between the vehicle body equivalent model and the power battery flexible body model, the excitation load is transferred from the vehicle body equivalent model to the power battery flexible body model; it should be noted that the virtual iterative model of the battery pack load spectrum needs to verify whether the center of mass position, mass, moment of inertia, etc. of each model component and assembly such as the vehicle body equivalent model and the power battery flexible body model are consistent with the actual model.

[0089] Exemplarily, S400: performing virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined, includes:

[0090] S410: performing iterative calculation on a virtual iterative model of a power battery load spectrum based on a preset multi-body dynamics model to obtain response signal data;

[0091] S420: Obtaining relative loss value data based on the response signal data and the vibration data of the preset point;

[0092] S430: If the relative loss value data is within a preset threshold range, generate load spectrum data of the power battery to be determined according to the response signal data.

[0093] Exemplarily, the vibration data at a preset point is used as the iteration target, and the relative loss value data is calculated based on the response signal data and the vibration data at the preset point; if the relative loss value data is within a preset threshold range, the response signal data meets the convergence requirement, and then the load spectrum data of the power battery to be determined is generated based on the response signal data.

[0094] Exemplarily, S410: the step of generating load spectrum data of the power battery to be determined according to the response signal data includes:

[0095] Generate the response transfer function of the virtual iterative model of the power battery load spectrum based on the response signal data;

[0096] The load spectrum data of the power battery to be determined is obtained based on the response transfer function.

[0097] Exemplarily, S100: the step of testing the power battery to be determined based on the road load spectrum of the electric vehicle to obtain vibration data of preset points of the power battery to be determined includes:

[0098] S110: Obtaining a road load spectrum of the electric vehicle;

[0099] S120: Inputting the road load spectrum of the electric vehicle into the load spectrum bench test device to obtain the preset point vibration data of the power battery, wherein the power battery to be determined is installed in the electric vehicle based on the preset installation point, and the electric vehicle is set in the load spectrum bench test device.

[0100] Exemplarily, the road load spectrum of an electric vehicle may be an actually collected road load spectrum of an electric vehicle; thus, the road load spectrum collected from the actual vehicle is input into a load spectrum bench test device, and a load test is performed on the power battery to be determined by the load spectrum bench test device to obtain the vibration data of preset points of the power battery; further, the vibration data of the preset points is used as a virtual iteration target to further improve the accuracy of the power battery load spectrum.

[0101] In some embodiments, in combination Figure 1 to Figure 2 The load spectrum determination method of the power battery shown in the figure has the following specific implementation steps:

[0102] (1) Battery pack road load spectrum bench test;

[0103] The battery pack road load spectrum bench test uses the actual collected electric vehicle road spectrum and a 24-channel acceleration vibration test bench to obtain the vibration data (including displacement, acceleration, etc.) of individual positions of the power battery pack used in the actual vehicle under comprehensive cycle road conditions or other actual road conditions as the target of virtual iteration;

[0104] Among them, the 24-channel acceleration vibration test bench includes a 24-channel axis-coupled road simulation test system, a data acquisition system, a three-axis capacitive acceleration sensor, a single-axis capacitive acceleration sensor, and some other consumables;

[0105] (2) Establishment of the flexible body model of power battery;

[0106] The power battery flexible body model includes two parts:

[0107] Part 1: Simplification of the power battery geometric model (which can be a CAD digital model of the battery pack); import the power battery geometric model into the finite element calculation software for meshing and modal calculation. Then generate a flexible body model of the battery pack. The flexible body of the battery pack needs to be connected to the vehicle body, and the corresponding connection points are reserved when the battery pack is meshed. The finite element model is established using a precise geometric model. This application uses finite element software for finite element pre-processing. After the geometric model is imported into the analysis software, it undergoes a series of processing to generate a mesh model. In order to keep the battery structure consistent with the actual situation, each module is meshed in detail and the module connection method is determined. When dividing the finite element mesh, perform special processing on different components, and then generate the mnf flexible body file through the finite element software.

[0108] Part 2: Import the power battery geometric model after finite element processing into the dynamics software to generate the battery pack flexible body, thereby completing the establishment of the power battery flexible body model;

[0109] (3) Modeling of a six-channel virtual test bench;

[0110] The multi-channel virtual test bench model provided in the embodiment of the present application may be a six-channel virtual test bench;

[0111] The six-channel virtual test bench modeling is to establish the excitation source of the power battery in the dynamics software. The virtual test bench contains six channels, including three vertical columns, one longitudinal column, and two lateral columns, which can simulate six-degree-of-freedom motion;

[0112] The power battery flexible body model and the six-channel virtual test bench model are modeled separately and then combined to obtain a vehicle body-battery pack six-channel virtual iterative model;

[0113] An assembly combination is established through the subsystem to establish a virtual iteration model of the battery pack load spectrum; the virtual iteration model of the battery pack load spectrum needs to verify whether the center of mass position, mass, moment of inertia, etc. of each component and assembly such as the vehicle body and the battery pack system are consistent with the actual model;

[0114] The force of the six-channel virtual test bench is applied to the vehicle body. The load is transferred from the vehicle body to the power battery through the connection between the vehicle body and the power battery. The vehicle body should consider its own mass and moment of inertia;

[0115] Optionally, in the actual assembly of electric vehicles and power batteries, the power battery is connected to the vehicle body by bolts, and there are 14 left and right connecting bolts of the power battery; in order to fully reflect the actual vibration of the tested components and improve the signal-to-noise ratio of the measurement, in the process of establishing the power battery flexible body model, the 1, 6, and 7 bolt installation points on the left side of the power battery and the 1, 4, and 5 bolt installation points on the right side are selected as the connection points of the virtual test bench; in order to prevent problems such as drift and flipping that may occur during the simulation process. The displacement and force hybrid drive method is used as the input excitation signal; the left 1 and 7 bolt connection points and the right 1 bolt connection point are the vertical Z-direction displacement loading positions, the left 6 bolt connection points are the front and rear X-direction force loading positions, and the right 4 and 5 bolt connection points are the left and right Y-direction force loading positions;

[0116] (4) Virtual iterative calculation;

[0117] The virtual iterative calculation is to obtain the load spectrum of the battery pack through virtual iterative model of the power battery load spectrum, combined with the obtained road spectrum of the electric vehicle battery pack, and to obtain the load spectrum of the battery pack through virtual iterative solution;

[0118] The virtual iteration refers to the process of continuously calling the multi-body dynamics model for calculation, and solving it jointly through ADAMS and iterative software in the solving environment of iterative software;

[0119] The iterative software can call the model of ADAMS software to perform iterative calculation by associating the correct read and write paths;

[0120] In order to obtain the response transfer function of the system, the Pink noise is first input to obtain the response of the system;

[0121] The transfer function of the system is calculated by the relationship between the noise and the response of the multi-body model;

[0122] The noise signal is generated by an amplitude characteristic defined in the frequency domain;

[0123] Determine the convergence of the iterative calculation. After defining the parameters required for the iteration, you can perform virtual iterative calculation. During the calculation process, monitor the relative damage values ​​of the response signal and the target signal in real time to confirm the convergence of the iteration.

[0124] Specifically, in the present application, the battery pack road load spectrum bench test obtains the acceleration of individual positions of the power battery pack by loading the actual collected electric vehicle road spectrum on a twenty-four-channel vibration test bench as the target of virtual iteration; the power battery load spectrum virtual iteration model is composed of a power battery flexible body model, a vehicle body equivalent model and a six-channel virtual test bench model.

[0125] Specifically, the virtual iterative calculation in this application refers to the iterative calculation of the six-channel virtual iterative model of the vehicle body-battery pack using load iteration software. The six-channel virtual test bench is used as an excitation source, which can provide displacement excitation and acceleration excitation. The virtual iterative model of the power battery is used as a response object. Under the excitation generated by the excitation source, the response object generates displacement and acceleration;

[0126] Specifically, the virtual iterative calculation in this application requires iterative convergence judgment, and the basis for judgment is as follows: Figure 5 As shown, the relative damage value is used for judgment; specifically, if the relative damage value is between 0.5 and 1.5, it is judged to be converged, and the closer the relative damage value is to 1, the higher the degree of convergence.

[0127] Specifically, the power battery and the vehicle body in the embodiment of the present application have 7 bolt connection points on each side, and acceleration sensors are arranged at the 7 bolt connection points on the left side to collect the acceleration response of the power battery pack when the 24-channel vibration test bench loads the actual collected electric vehicle road spectrum; the acceleration of these 7 bolt connection points is used as the target of virtual iteration;

[0128] This application obtains the power battery load spectrum through virtual iteration, realizes fatigue durability analysis of the power battery, shortens the test cycle, and provides a set of effective stress testing and benchmarking optimization processes;

[0129] (5) Convergence judgment;

[0130] Iterative calculation is the process of obtaining the response of the system. The response and the target are constantly compared. The closer the relative loss between the two is to 1, the better the degree of convergence.

[0131] In some implementations, a specific method for determining a battery load spectrum according to an embodiment of the present application includes the following steps:

[0132] Through the vehicle bench test, the actual road spectrum of the vehicle is loaded to obtain the vibration acceleration of several positions of the power battery pack used in the actual vehicle under comprehensive cycle road conditions;

[0133] The digital model of the battery pack is appropriately simplified to establish a finite element model of the battery pack including the shell and the module. Through modal analysis, the flexible body model of the battery pack is obtained.

[0134] The vehicle body equivalent mass block and the flexible battery pack are connected to establish a rigid-flexible coupling dynamic model of the vehicle body and the battery pack;

[0135] A six-channel battery pack test bench was established in ADAMS software, and a virtual vibration test bench for iterative calculation was established with the rigid-flexible coupling multi-body dynamics model of the vehicle body and battery pack. Virtual iterative calculations were performed through iterative software, and the convergence of the iterative calculations was verified through signal comparison. If converged, the calculation was completed and the load spectrum of the battery pack was obtained.

[0136] This application uses a combination of simulation and testing methods, and through the measured load spectrum of key parts, using virtual iteration technology, it can accurately predict the load spectrum of other positions, which not only solves the problem of not being able to directly obtain the battery pack load, but also solves the blindness problem caused by directly using national standard calculations;

[0137] Combined with the 24-channel vehicle test mentioned above, a virtual test bench based on the body-battery pack rigid-flexible coupling model was built. Through the combination of virtual iterative calculation and vehicle testing, it not only better reflects the vibration characteristics of the vehicle, but also obtains the load spectrum of the power battery pack. It is a reliable, convenient and scientific calculation method. The convergence of the iterative calculation is judged by relative damage. If the relative damage value is between 0.5 and 1.5, the iterative calculation meets the convergence requirements. Specifically, the consistency of each channel signal in the time domain and frequency domain is also compared. If the consistency is good, it means that the accuracy of the virtual iteration meets the requirements of engineering analysis. The method of this application provides important load spectrum input for structural fatigue analysis of battery packs, shortening the research and development cycle.

[0138] Please attend Figure 3 , Figure 3 A structural block diagram of a load spectrum determination system for a power battery provided in an embodiment of the present application; the load spectrum determination system for a power battery includes:

[0139] The testing module 100 is used to test the power battery to be determined based on the road load spectrum of the electric vehicle, and obtain vibration data of preset points of the power battery to be determined;

[0140] A battery flexible body module 200 is used to establish a power battery flexible body model of the power battery to be determined;

[0141] A virtual iteration module 300 is used to generate a virtual iteration model of a power battery load spectrum based on a power battery flexible body model;

[0142] The load spectrum determination module 400 is used to perform virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined.

[0143] Exemplarily, the battery flexible body module 200 is specifically used for:

[0144] Obtaining a power battery geometric model of a power battery to be determined;

[0145] Finite element processing is performed based on the power battery geometric model, and meshing and modal calculation are performed on the power battery geometric model to obtain a power battery flexible body model, wherein the power battery flexible body model reserves corresponding connection points when meshing, and the power battery flexible body model is connected to the vehicle body equivalent model through the connection points.

[0146] Exemplarily, the virtual iteration module 300 is specifically used for:

[0147] Establish multi-channel virtual test bench model and vehicle body equivalent model;

[0148] Generate a rigid-flexible coupling multi-body dynamics model of the vehicle body and battery pack based on the vehicle body equivalent model and the power battery flexible body model;

[0149] Based on the body-battery pack rigid-flexible coupled multi-body dynamics model and the multi-channel virtual test bench model, a virtual iterative model of the power battery load spectrum is generated. The multi-channel virtual test bench model serves as an excitation source to provide displacement excitation and acceleration excitation to the body equivalent model. The power battery flexible body model serves as a response object. Under the excitation generated by the excitation source, the response object generates displacement response and acceleration response.

[0150] Exemplarily, the load spectrum determination module 400 is specifically used for:

[0151] Iteratively calculate the virtual iterative model of the power battery load spectrum based on the preset multi-body dynamics model to obtain response signal data;

[0152] Obtaining relative loss value data based on response signal data and preset point vibration data;

[0153] If the relative loss value data is within a preset threshold range, load spectrum data of the power battery to be determined is generated according to the response signal data.

[0154] Exemplarily, the load spectrum determination module 400 is further used for:

[0155] The step of generating load spectrum data of the power battery to be determined according to the response signal data comprises:

[0156] Generate the response transfer function of the virtual iterative model of the power battery load spectrum based on the response signal data;

[0157] The load spectrum data of the power battery to be determined is obtained based on the response transfer function.

[0158] Exemplarily, the test module 100 is specifically used for:

[0159] Obtaining road load spectrum of electric vehicles;

[0160] The road load spectrum of the electric vehicle is input into the load spectrum bench test device to obtain the vibration data of the preset points of the power battery, wherein the power battery to be determined is installed in the electric vehicle based on the preset installation points, and the electric vehicle is set in the load spectrum bench test device.

[0161] It should be noted that the load spectrum determination system of the power battery provided in the embodiment of the present application is Figure 1 and Figure 2 The method embodiments shown correspond to each other and will not be described again here to avoid repetition.

[0162] This application also provides an electronic device, see Figure 4 , Figure 4 A block diagram of an electronic device provided in an embodiment of the present application. The electronic device may include a processor 510, a communication interface 520, a memory 530, and at least one communication bus 540. The communication bus 540 is used to realize direct connection and communication between these components. The communication interface 520 of the electronic device in the embodiment of the present application is used to communicate signaling or data with other node devices. The processor 510 may be an integrated circuit chip with signal processing capabilities.

[0163] The processor 510 mentioned above can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor 510 can also be any conventional processor, etc.

[0164] The memory 530 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electric erasable programmable read-only memory (EEPROM), etc. The memory 530 stores computer-readable instructions. When the computer-readable instructions are executed by the processor 510, the electronic device can execute the above-mentioned Figure 1 to Figure 2 The method embodiment involves various steps.

[0165] Optionally, the electronic device may further include a storage controller and an input / output unit.

[0166] The memory 530, storage controller, processor 510, peripheral interface, input and output unit components are directly or indirectly electrically connected to each other to achieve data transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses 540. The processor 510 is used to execute executable modules stored in the memory 530, such as software function modules or computer programs included in the electronic device.

[0167] The input and output unit is used to provide users with the task creation and to create a start optional time period or preset execution time for the task to realize the interaction between the user and the server. The input and output unit can be, but is not limited to, a mouse and a keyboard.

[0168] Understandably, Figure 4 The structure shown is for illustration only, and the electronic device may also include Figure 4 More or fewer components as shown, or with Figure 4 Different configurations are shown. Figure 4 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0169] An embodiment of the present application further provides a storage medium having instructions stored thereon. When the instructions are run on a computer, the computer program is executed by a processor to implement the method described in the method embodiment. To avoid repetition, the method will not be described here.

[0170] The present application also provides a computer program product, which, when executed on a computer, enables the computer to execute the method described in the method embodiment.

[0171] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0172] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0173] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0174] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0175] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0176] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for determining a load spectrum of a power battery, characterized in that: include: Testing the power battery to be determined based on the road load spectrum of the electric vehicle to obtain vibration data of preset points of the power battery to be determined; Establishing a power battery flexible body model of the power battery to be determined; Generate a power battery load spectrum virtual iteration model based on the power battery flexible body model; A virtual iterative calculation is performed based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined.

2. The method for determining the load spectrum of a power battery according to claim 1, characterized in that: The step of establishing a power battery flexible body model of the power battery to be determined comprises: Acquiring a power battery geometric model of the power battery to be determined; Finite element processing is performed based on the power battery geometric model, and meshing and modal calculation are performed on the power battery geometric model to obtain a power battery flexible body model, wherein the power battery flexible body model reserves corresponding connection points when meshing, and the power battery flexible body model is connected to the vehicle body equivalent model through the connection points.

3. The method for determining the load spectrum of a power battery according to claim 1 or 2, characterized in that: The step of generating a virtual iterative model of a power battery load spectrum based on the power battery flexible body model comprises: Establish multi-channel virtual test bench model and vehicle body equivalent model; Based on the vehicle body equivalent model and the power battery flexible body model, a vehicle body-battery pack rigid-flexible coupling multi-body dynamics model is generated; Based on the vehicle body-battery pack rigid-flexible coupled multi-body dynamics model and the multi-channel virtual test bench model, a virtual iterative model of the power battery load spectrum is generated, wherein the multi-channel virtual test bench model serves as an excitation source to provide displacement excitation and acceleration excitation to the vehicle body equivalent model; the power battery flexible body model serves as a response object, and under the excitation generated by the excitation source, the response object generates a displacement response and an acceleration response.

4. The method for determining the load spectrum of a power battery according to claim 1, characterized in that: The step of performing virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined includes: Iteratively calculating the power battery load spectrum virtual iterative model based on a preset multi-body dynamics model to obtain response signal data; Obtaining relative loss value data based on the response signal data and the preset point vibration data; If the relative loss value data is within a preset threshold range, the load spectrum data of the power battery to be determined is generated according to the response signal data.

5. The method for determining the load spectrum of a power battery according to claim 4, characterized in that: The step of generating the load spectrum data of the power battery to be determined according to the response signal data comprises: Generate a response transfer function of the power battery load spectrum virtual iterative model based on the response signal data; The load spectrum data of the power battery to be determined is obtained based on the response transfer function.

6. The method for determining the load spectrum of a power battery according to claim 1, characterized in that: The step of testing the power battery to be determined based on the road load spectrum of the electric vehicle and obtaining the vibration data of the preset points of the power battery to be determined comprises: Obtaining road load spectrum of electric vehicles; The road load spectrum of the electric vehicle is input into a load spectrum bench test device to obtain the preset point vibration data of the power battery, wherein the power battery to be determined is installed in the electric vehicle based on the preset installation point, and the electric vehicle is set on the load spectrum bench test device.

7. A load spectrum determination system for a power battery, characterized in that: include: A testing module, used to test the power battery to be determined based on the road load spectrum of the electric vehicle, and obtain vibration data of preset points of the power battery to be determined; A battery flexible body module, used to establish a power battery flexible body model of the power battery to be determined; A virtual iteration module, used for generating a virtual iteration model of a power battery load spectrum based on the power battery flexible body model; The load spectrum determination module is used to perform virtual iterative calculation based on the preset point vibration data and the power battery load spectrum virtual iterative model to obtain the load spectrum data of the power battery to be determined.

8. The load spectrum determination system for a power battery according to claim 7, characterized in that: The battery flexible body module is specifically used for: Acquiring a power battery geometric model of the power battery to be determined; Finite element processing is performed based on the power battery geometric model, and meshing and modal calculation are performed on the power battery geometric model to obtain a power battery flexible body model, wherein the power battery flexible body model reserves corresponding connection points when meshing, and the power battery flexible body model is connected to the vehicle body equivalent model through the connection points.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for determining the load spectrum of a power battery as claimed in any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed on a computer, the computer executes the method for determining a load spectrum of a power battery according to any one of claims 1 to 6.

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