Temperature state determination method and device, storage medium and electronic device

Abstract

The invention discloses a temperature state determination method and device, a storage medium and an electronic device, and the method comprises the steps: obtaining the working current of a battery pack of a vehicle, and enabling the working current to at least comprise a charging current and a discharging current; the working current is input into a thermoelectric coupling model deployed in a battery management system of the vehicle so as to determine the temperature state of the battery pack, and the thermoelectric coupling model is a model established after battery cells of the battery pack are partitioned through temperature distribution of the battery pack in the working process. According to the method, the problems that the application effect of a thermal model constructed by a traditional method is poor and the temperature state of the battery pack cannot be accurately determined due to the fact that the number of battery cells of the battery pack is large and the structure is complex in the prior art are solved, and the technical effect of accurately determining the temperature state of the battery pack is achieved.

Description

Technical Field

[0001] This application relates to the field of battery management systems for new energy vehicles, and more specifically, to a method and apparatus for determining temperature state, a storage medium, and an electronic device. Background Technology

[0002] Currently, new energy vehicles are widely used, and consumers are increasingly demanding higher standards for overall vehicle energy consumption, accurate driving range, and battery (battery pack) lifespan. Generally, a vehicle's battery system includes a sampling system and a thermal management system. The sampling system samples cell voltage, current, and temperature; the thermal management system ensures the cells operate within a suitable temperature range; and the battery management system estimates the battery's state of charge (SOC) and state of health (SOH) based on the sampled information. In existing technologies, the inability to obtain cell temperature data makes accurate battery assessment difficult, leading to issues such as short driving range and inaccurate remaining range estimates, causing user complaints.

[0003] In related technologies, attempts have been made to solve the problem of the inability to obtain the temperature state of the battery cells by constructing a thermal model of the battery pack. However, due to the large number of battery cells and the complex structure of the power battery pack, the thermal model constructed by traditional methods has problems such as limited calculation accuracy, large amount of computation, weak scalability, and difficulty in embedding it into the battery management system for online application.

[0004] In related technologies, due to the large number of cells and complex structure of battery packs, the application effect of thermal models built by traditional methods is poor, and they cannot accurately determine the temperature state of the battery pack. There is currently no effective solution to this problem.

[0005] Therefore, it is necessary to improve the relevant technology to overcome the aforementioned defects. Summary of the Invention

[0006] This application provides a method and apparatus for determining temperature state, a storage medium, and an electronic device to at least solve the problem that the application effect of thermal models constructed by traditional methods is poor and cannot accurately determine the temperature state of the battery pack due to the large number of battery cells and the complex structure of the battery pack.

[0007] According to one aspect of the embodiments of this application, a method for determining temperature state is provided, applied to a vehicle, comprising: acquiring the operating current of the vehicle's battery pack, wherein the operating current includes at least: charging current and discharging current; inputting the operating current into a thermoelectric coupling model deployed in the vehicle's battery management system to determine the temperature state of the battery pack, wherein the thermoelectric coupling model is a model established by partitioning the battery pack's cells based on the temperature distribution of the battery pack during operation.

[0008] In an exemplary embodiment, before inputting the operating current into a thermoelectric coupling model deployed in the vehicle's battery management system to determine the temperature state of the battery pack, the method further includes: partitioning the battery pack's cells by the temperature distribution of the battery pack during operation, and establishing a cell cluster thermal model of the battery pack based on the obtained cell partitions; and interacting the cell cluster thermal model with a second-order RC equivalent circuit model to establish the thermoelectric coupling model.

[0009] In an exemplary embodiment, partitioning the battery cells of the battery pack according to the temperature distribution during the operation of the battery pack includes: determining the temperature distribution of the battery pack during the operation of the battery pack; dividing the battery cells of the battery pack into a central heat-generating zone and a peripheral heat-generating zone according to the temperature distribution, wherein the central heat-generating zone and the peripheral heat-generating zone are connected by thermal resistance.

[0010] In an exemplary embodiment, establishing a cell cluster thermal model of the battery pack through the obtained cell partitions includes: establishing a cell heat generation model corresponding to the cell through the cell partitions, and establishing a cell heat dissipation model corresponding to the cell through the cell partitions; and determining the cell cluster thermal model through the cell heat generation model and the cell heat dissipation model.

[0011] In an exemplary embodiment, establishing a cell heat generation model corresponding to the cell through the cell partitioning includes: calculating a first heat generation in the central heat generation area using the target principle, and calculating a second heat generation in the peripheral heat generation area using the target principle, wherein the cell partitioning includes: the central heat generation area and the peripheral heat generation area; and determining the cell heat generation model using the first heat generation and the second heat generation.

[0012] In an exemplary embodiment, establishing a cell heat dissipation model corresponding to the cell through the cell partitioning includes: determining the heat exchange between a first part and a second part of the battery pack, wherein the first part is any part among all parts of the battery pack, the second part is an adjacent part of the any part among other parts, and the other parts are all parts except the any part, and all parts include at least the cell partitioning. The cell heat dissipation model is determined through the heat exchange.

[0013] In an exemplary embodiment, determining the cell cluster thermal model using the cell heat generation model and the cell heat dissipation model includes: conducting charge-discharge tests on the battery pack based on orthogonal experiments to obtain a feature scenario dataset of the battery pack under each feature scenario, wherein each feature scenario is a scenario obtained by combining multiple target scenarios, including: temperature scenario, power scenario, thermal management state scenario, and vehicle state scenario; identifying parameters in the feature scenario dataset using the least squares method to determine the optimal parameters of the cell cluster thermal model under each feature scenario; and determining the cell cluster thermal model using the optimal parameters.

[0014] According to another aspect of the embodiments of this application, a temperature state determination device is provided, applied to a vehicle, comprising: an acquisition module for acquiring the operating current of the vehicle's battery pack, wherein the operating current includes at least: a charging current and a discharging current; and a determination module for inputting the operating current into a thermoelectric coupling model deployed in the vehicle's battery management system to determine the temperature state of the battery pack, wherein the thermoelectric coupling model is a model established by partitioning the battery pack's cells based on the temperature distribution of the battery pack during operation.

[0015] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored in the computer-readable storage medium, and the computer program is configured to execute the above-described method for detecting dust accumulation in photovoltaic modules when it is run.

[0016] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the dust accumulation detection method of the photovoltaic module through the computer program.

[0017] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program, which, when executed by a processor, provides the above-mentioned method for detecting dust accumulation in photovoltaic modules.

[0018] This application obtains the operating current of the vehicle's battery pack, wherein the operating current includes at least a charging current and a discharging current. The operating current is input into a thermoelectric coupling model deployed in the vehicle's battery management system to determine the temperature state of the battery pack. The thermoelectric coupling model is established by partitioning the battery pack's cells based on the temperature distribution during operation. In other words, the pre-established thermoelectric coupling model is based on the partitioning of the battery pack's cells and can be deployed in the battery management system. Therefore, when the vehicle's battery pack is operating, the operating current of the battery pack can be input into the pre-deployed thermoelectric coupling model in the battery management system to accurately determine the temperature state of the battery pack. Therefore, this technical solution solves the problem in related technologies where the large number and complex structure of battery pack cells lead to poor application effects of traditional methods in constructing thermal models, making it impossible to accurately determine the temperature state of the battery pack. This achieves the technical effect of accurately determining the temperature state of the battery pack. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a hardware structure block diagram of a vehicle using a method for determining temperature state according to an embodiment of this application.

[0022] Figure 2 This is a flowchart of a method for determining a temperature state according to an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of a clustered thermal model according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the cell area division according to an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of a clustered thermal-electric coupling model according to an embodiment of this application;

[0026] Figure 6 This is an orthogonal experimental design diagram for parameter calibration based on the embodiments of this application;

[0027] Figure 7This is a charging temperature prediction diagram based on an embodiment of this application;

[0028] Figure 8 This is a structural block diagram of a temperature state determination device according to an embodiment of this application. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] The methods and embodiments provided in this application can be executed in a vehicle, computer terminal, or similar computing device. Taking operation in a vehicle as an example, Figure 1 This is a hardware structure block diagram of a vehicle using a method for determining temperature state according to an embodiment of this application. For example... Figure 1 As shown, a vehicle may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor (MCU) or a field-programmable gate array (FPGA)) and a memory 104 for storing data are also shown. The vehicle may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the vehicle described above. For example, the vehicle may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1The different configurations shown.

[0032] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the temperature state determination method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the vehicle via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0033] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the vehicle's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0034] This embodiment provides a method for determining temperature status, which is applied to the aforementioned vehicle. Figure 2 This is a flowchart of a method for determining a temperature state according to an embodiment of this application, such as... Figure 2 As shown, the process includes the following steps S202-S204:

[0035] Step S202: Obtain the operating current of the vehicle's battery pack, wherein the operating current includes at least: charging current and discharging current;

[0036] Step S204: Input the operating current into the thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack, wherein the thermoelectric coupling model is a model established by partitioning the cells of the battery pack through the temperature distribution of the battery pack during operation.

[0037] Through the above steps, the operating current of the vehicle's battery pack is obtained, wherein the operating current includes at least: charging current and discharging current. The operating current is input into a thermoelectric coupling model deployed in the vehicle's battery management system to determine the temperature state of the battery pack. The thermoelectric coupling model is established by partitioning the battery pack's cells based on the temperature distribution during operation. In other words, the pre-established thermoelectric coupling model is based on the partitioning of the battery pack's cells and can be deployed in the battery management system. Therefore, when the vehicle's battery pack is operating, the operating current of the battery pack can be input into the pre-deployed thermoelectric coupling model in the battery management system to accurately determine the temperature state of the battery pack. Therefore, the above technical solution solves the problem in related technologies where the large number of battery cells and complex structure of the battery pack lead to poor application effects of traditional methods in constructing thermal models, making it impossible to accurately determine the temperature state of the battery pack. This achieves the technical effect of accurately determining the temperature state of the battery pack.

[0038] In some embodiments, before inputting the operating current into a thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack, the method further includes: partitioning the cells of the battery pack according to the temperature distribution of the battery pack during operation, and establishing a cell cluster thermal model of the battery pack based on the obtained cell partitions; and interacting the cell cluster thermal model with a second-order RC equivalent circuit model to establish the thermoelectric coupling model.

[0039] Optionally, the battery cells of the battery pack are partitioned based on the temperature distribution of the battery pack during operation, including: determining the temperature distribution of the battery pack during operation; dividing the battery cells of the battery pack into a central heat-generating zone and a peripheral heat-generating zone based on the temperature distribution, wherein the central heat-generating zone and the peripheral heat-generating zone are connected by thermal resistance.

[0040] It is understandable that when the battery pack is placed with the cover on top and the tray on the bottom, viewed from the side, the central heat-generating area and the surrounding heat-generating areas appear as follows: Figure 3 As shown, the central heat-generating zone corresponds to Figure 3 The central area of ​​the battery cell and the surrounding heat-generating area correspond to Figure 3 The peripheral cells in the battery pack; when viewed from above, the relationship between the central heat-generating area and the peripheral heat-generating area is as follows: Figure 4 As shown. Optionally, the temperature distribution of the battery pack during operation is determined empirically. However, it is also possible to perform real-time monitoring of multiple battery packs in operation, and determine the temperature distribution in the above embodiment based on the temperature distribution corresponding to each of the multiple battery packs.

[0041] Optionally, a cell cluster thermal model of the battery pack is established based on the obtained cell partitioning; the cell cluster thermal model is then interacted with a second-order RC equivalent circuit model to establish the thermoelectric coupling model, including:

[0042] By interacting the aforementioned cell cluster thermal model with the second-order RC equivalent circuit model through current and cell temperature, a thermoelectric coupling model can be established to effectively reflect the electrical characteristics of the battery pack at different temperatures. Specifically, as follows... Figure 5 As shown, Figure 5 The equivalent circuit model in the model is the second-order RC equivalent circuit model.

[0043] Furthermore, such as Figure 5 As shown, the cell cluster thermal model and the second-order RC equivalent circuit model interact through current and cell temperature, including: the cell cluster thermal model outputs thermal characteristics (including heat generation and heat dissipation) to the second-order RC equivalent circuit model; and the second-order RC equivalent circuit model outputs electrical characteristics (including current, charge, and voltage) to the cell cluster thermal model.

[0044] In other words, the cell cluster thermal model established in this application embodiment is scalable, and the thermoelectric coupling model established after interaction with the equivalent circuit model can be used to analyze the influence of temperature on battery operation.

[0045] In some optional embodiments, the cell cluster thermal model of the battery pack is established by obtaining the cell partitions, including: establishing a cell heat generation model corresponding to the cell through the cell partitions, and establishing a cell heat dissipation model corresponding to the cell through the cell partitions; and determining the cell cluster thermal model through the cell heat generation model and the cell heat dissipation model.

[0046] The cell cluster thermal model determined by the cell heat generation model and the cell heat dissipation model is as follows: Figure 3 As shown.

[0047] Furthermore, establishing a cell heat generation model corresponding to the cell through the cell partitioning includes: calculating the first heat generation of the central heat generation area through the target principle, and calculating the second heat generation of the peripheral heat generation area through the target principle, wherein the cell partitioning includes: the central heat generation area and the peripheral heat generation area; and determining the cell heat generation model through the first heat generation and the second heat generation.

[0048] Optionally, the target principle used in this embodiment is the Bernardi principle. Since the central heat-generating zone and the surrounding heat-generating zone in this embodiment are abstracted, and the relevant thermoelectric parameters are not easily obtained, a correction strategy is introduced to calculate heat generation in this embodiment. The specific formulas for calculating the first and second heat generation are shown in formula (1):

[0049]

[0050] Where q1 represents the first or second heat generation; f(λ1) and f(λ2) are correction mechanisms introduced considering the battery pack structure, cell arrangement, and different operating scenarios; I represents the operating current of the battery pack; U ocv U is used to represent the open-circuit voltage of the battery pack, and T is used to represent the terminal voltage of the battery pack. Specifically, when calculating the first heat generation, T represents the cell temperature in the central heat generation zone, and when calculating the second heat generation, T represents the cell temperature in the peripheral heat generation zone.

[0051] Furthermore, establishing a cell heat dissipation model corresponding to the cell through the cell partitioning includes: determining the heat exchange between a first part and a second part of the battery pack, wherein the first part is any part among all parts of the battery pack, the second part is the adjacent part of the any part among the other parts, and the other parts are all parts except the any part, and the all parts include at least the cell partitioning. The cell heat dissipation model is determined through the heat exchange.

[0052] The first part and the second part exchange heat through the thermal resistance coefficient and temperature difference between them. For the specific calculation of the heat exchange between the first part and the second part, please refer to formula (2):

[0053]

[0054] Where q2 represents heat exchange, ΔT represents the temperature difference between the first part and the second part, and g(R) represents the thermal resistance coefficient between the first part and the second part.

[0055] Optional, all parts include but are not limited to, such as Figure 3 The components shown include: peripheral cell area, central cell area, top cover, air inside the package, thermally conductive adhesive, cooling medium (e.g., coolant), tray, etc.

[0056] It should be noted that the thermal resistance coefficient between the first part and the second part includes, but is not limited to: the thermal resistance between the cells (i.e., thermal resistance coefficient) g(R1), the thermal resistance between the cell and the air g(R2), the thermal resistance between the casing and the air g(R3), the thermal resistance between the water-cooling plate and the coolant g(R4), the thermal resistance between the cell and the thermally conductive adhesive g(R5), and the thermal resistance between the thermally conductive adhesive and the water-cooling plate g(R6). Corresponding to the thermal resistance coefficient, the temperature difference between the first part and the second part includes, but is not limited to: the temperature difference between the cells, the temperature difference between the cell and the air, the temperature difference between the casing and the air, the temperature difference between the water-cooling plate and the coolant, the temperature difference between the cell and the thermally conductive adhesive, and the temperature difference between the thermally conductive adhesive and the water-cooling plate.

[0057] When calculating the heat exchange between the first part and the second part, the corresponding thermal resistance and temperature difference can be substituted into formula (2). For example, when calculating the heat exchange between the cells, the thermal resistance coefficient and temperature difference between the central heat generation area and the surrounding heat generation area can be substituted into formula (2) to obtain the heat exchange between the central heat generation area and the surrounding heat generation area.

[0058] In an exemplary embodiment, determining the cell cluster thermal model using the cell heat generation model and the cell heat dissipation model includes: conducting charge-discharge tests on the battery pack based on orthogonal experiments to obtain a feature scenario dataset of the battery pack under each feature scenario, wherein each feature scenario is a scenario obtained by combining multiple target scenarios, including: temperature scenario, power scenario, thermal management state scenario, and vehicle state scenario; identifying parameters in the feature scenario dataset using the least squares method to determine the optimal parameters of the cell cluster thermal model under each feature scenario; and determining the cell cluster thermal model using the optimal parameters.

[0059] Optionally, the temperature scenario set T = {low temperature, normal temperature, high temperature}, the power scenario set S = {low power, medium power, high power}, the thermal management state set M = {battery heating, battery cooling, no thermal management}, and the vehicle state set V = {driving, charging, stationary}.

[0060] Each characteristic scenario includes a sub-scenario of each of the multiple target scenarios. For example, each characteristic scenario could be: low temperature, medium charge level, battery heating, and driving. Then, charge-discharge tests based on orthogonal experiments are performed on the battery pack under each characteristic scenario. The resulting test data constitutes the characteristic scenario dataset for each characteristic scenario. The orthogonal experimental design can be as follows: Figure 6 As shown.

[0061] Furthermore, by using the least squares method to identify parameters in the feature scenario dataset, the optimal parameters of the cell cluster thermal model under each feature scenario can be determined using formula (3):

[0062]

[0063] Among them, Tem PreCell1 This is an estimate of the maximum temperature, Tem. MeaCell1 Tem is the maximum temperature measurement value. PreCell2 This is the minimum temperature estimate, Tem MeaCell2 α represents the minimum temperature measurement value, β represents the weighting coefficients, n represents the number of test data sets included in the feature scene dataset, and k represents the k-th data set out of the n data sets.

[0064] The estimated maximum and minimum temperatures are obtained through the cell cluster thermal model during the charge-discharge test; the measured maximum and minimum temperatures are obtained through sensors during the charge-discharge test. Optionally, each set of test data in the feature scenario dataset includes both the estimated maximum and minimum temperatures and the measured maximum and minimum temperatures. The optimal parameters are those used by the cell cluster thermal model when collecting the target set of test data from the feature scenario dataset, where the target set of test data is the target set of test data corresponding to the final calculated Q. The parameters used by the cell cluster thermal model are the thermal resistance coefficient, operating current, and temperature difference, as described in the above embodiment.

[0065] Obviously, the embodiments described above are only some embodiments of this application, and not all embodiments. To better understand the above method, the following description, in conjunction with embodiments, illustrates the process, but is not intended to limit the technical solutions of the embodiments of this application. Specifically:

[0066] To address the issue that traditional methods for constructing thermal models in battery packs often fail to accurately determine the temperature state due to the large number of cells and complex structure, this invention constructs an equivalent thermal model of the battery pack using a cluster partitioning method. This includes dividing the cells into clusters, establishing a cell gradient heat generation model (i.e., a cell heat generation model), and a regionalized heat dissipation model (i.e., a cell heat dissipation model). Then, a standard identification scenario database is constructed to identify the parameters of the thermal model (i.e., the cell cluster thermal model) to obtain a thermo-electric coupling model (i.e., a thermo-electric coupling model).

[0067] The main applications of this thermo-electric coupling model include: predicting future temperatures, improving the accuracy of driving range prediction, enabling predictable cell temperature management, and extending battery life; providing an equivalent replacement for temperature sampling sensors when they fail, thus improving the robustness of the battery management system; and using it on battery simulation platforms to verify strategies in the BMS software development process, shorten the development cycle, reduce the frequency of battery pack and real vehicle testing, and lower development costs.

[0068] The cell cluster thermal model planning method provided in this embodiment of the invention has the following specific steps:

[0069] Step 1: Cell Zone Division. Based on the temperature distribution during the actual operation of the battery pack, the entire cell pack is divided into a central heat-generating zone and a peripheral heat-generating zone (e.g., ...). Figure 3 and Figure 4 As shown), the two regions are connected by thermal resistance. More specifically, in Figure 3 The entire battery pack is divided into several parts: the central cell area, the peripheral cell area, the internal air, the thermal conductive adhesive, the cooling medium, and the tray and top cover.

[0070] Step 2: Cell heat generation modeling. The heat generation of the cell cluster is calculated based on Bernardi principle. Since the cluster is an abstract model, the relevant thermoelectric parameters are not easy to obtain. Therefore, a correction strategy is introduced in this invention to calculate the heat generation. The calculation formula for the heat generation is shown in the above formula (1).

[0071] Step 3: Cell heat dissipation modeling, defining heat exchange between different parts of the battery pack based on the cluster thermal model. Heat exchange between different parts is achieved through thermal resistance coefficient and temperature difference. The specific calculation formula for heat exchange is given in formula (2) in the above embodiment. The thermal resistance between cells, between cells and air, between the casing and air, between the water-cooled plate and coolant, between cells and thermally conductive adhesive, and between thermally conductive adhesive and water-cooled plate are defined abstract parameters.

[0072] Step 4: Establish a scenario library. To ensure the applicability of the full-condition thermal model, the parameter identification conditions are selected as follows: temperature scenario set T = {low temperature, normal temperature, high temperature}, power scenario set S = {low power, medium power, high power}, thermal management state set M = {battery heating, battery cooling, no thermal management}, and vehicle state set V = {driving, charging, stationary}. The parameter identification feature conditions (equivalent to each feature scenario) combinations are selected through orthogonal experimental design.

[0073] Step 5: Identification of thermal model parameters for battery cell clusters. In order to reduce model parameters in this embodiment of the invention, the thermal model of the battery pack has been abstracted (i.e., the division of the central heat generation area and the surrounding heat generation area). Therefore, in this embodiment of the invention, it is also necessary to calibrate the above thermal model through parameter identification. Specifically, with the estimation error of the maximum and minimum temperature of the battery cells as the optimization target, the thermal model parameters in steps 2 and 3 are identified based on the characteristic operating condition data in step 4 (equivalent to the characteristic scene dataset). The specific identification formula is shown in the above formula (3).

[0074] Step 6: Establish a thermal-electric coupling model. Interact the obtained thermal model with the second-order RC equivalent circuit model of the battery pack using current and cell temperature to establish an integrated thermal-electric coupling model (e.g., ...). Figure 5 It can effectively reflect the electrical characteristics of the battery pack at different temperatures.

[0075] Through the above steps, the advantages of the thermal model established in this application embodiment compared with the existing thermal model are: 1) The solid model is simplified, reducing the model complexity and the number of parameters, and can be integrated into the battery management system (BMS) controller for application; 2) The battery pack cluster retains the maximum and minimum temperature characteristics, which can be used for battery strategy control; 3) The thermal model is scalable, and the thermoelectric coupling model established after interaction with the equivalent circuit model can be used to analyze the influence of temperature on battery operation.

[0076] Optionally, the actual application process of this application embodiment is as follows: First, a battery cluster thermal model is established, which can be implemented using, but is not limited to, Matlab / Simulink tools. Charge and discharge tests are performed on the battery pack, and test data is extracted based on orthogonal experiments to obtain a feature scene dataset (such as...). Figure 6 The least squares method was used to identify the parameters of the battery cluster thermal model, resulting in a cell cluster thermal model with high fitting accuracy. This model was then used in conjunction with a second-order RC equivalent circuit model to establish a thermoelectric coupling model. Using the charging current as the external excitation input model, the temperature change of the battery pack throughout the charging process can be predicted. Figure 7 As shown.

[0077] In summary, the solution of this application has the following advantages: This invention adopts a cluster-based cell modeling scheme, abstracting hundreds of cells into two regions according to temperature gradients, greatly reducing model parameters and enabling online model prediction. A correction strategy is introduced to the Bernardi formula to calibrate the heat generation of the clustered cells, improving the temperature estimation accuracy of the thermal model. A standard scenario library is established, employing an efficient, fast, and economical orthogonal experimental method and a unified testing process, enabling rapid parameter identification for different types of battery packs and achieving one-time development for multiple product applications. In other words, this application reduces model complexity while fully preserving the maximum and minimum boundary temperature states during battery operation. This allows the resulting model to be integrated into a battery management system, estimating the real-time temperature of the battery pack online and predicting temperature change trends over a future time window. It can make decisions in advance regarding battery pack heating or cooling actions, thereby improving battery thermal management efficiency and reducing thermal management energy consumption. Simultaneously, it can be verified against sensor temperature sampling values ​​to determine whether battery thermal runaway propagation has occurred. In addition, since the embodiments of this application do not rely on cell temperature sensors, the number of battery pack sensors can be reduced to a certain extent, thereby reducing the overall development cost of the battery pack.

[0078] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0079] This embodiment also provides a temperature state determination device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0080] Figure 8 This is a structural block diagram of a temperature state determination device according to an embodiment of this application. The device includes:

[0081] The acquisition module 82 is used to acquire the operating current of the vehicle's battery pack, wherein the operating current includes at least: charging current and discharging current;

[0082] The determination module 84 is used to input the operating current into a thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack. The thermoelectric coupling model is a model established by partitioning the cells of the battery pack based on the temperature distribution of the battery pack during operation.

[0083] The aforementioned device acquires the operating current of the vehicle's battery pack, which includes at least a charging current and a discharging current. This operating current is then input into a thermoelectric coupling model deployed within the vehicle's battery management system to determine the temperature state of the battery pack. The thermoelectric coupling model is established by partitioning the battery pack's cells based on the temperature distribution during operation. In other words, the pre-established thermoelectric coupling model is based on the partitioning of the battery pack's cells and can be deployed within the battery management system. Therefore, when the vehicle's battery pack is operating, the operating current of the battery pack can be input into the pre-deployed thermoelectric coupling model within the battery management system to accurately determine the battery pack's temperature state. Thus, this technical solution solves the problem in related technologies where the large number and complex structure of battery pack cells lead to poor application effects of traditional thermal models, making it impossible to accurately determine the battery pack's temperature state. This achieves the technical effect of accurately determining the battery pack's temperature state.

[0084] In an exemplary embodiment, the apparatus further includes a modeling module for: partitioning the cells of the battery pack by the temperature distribution of the battery pack during operation, and establishing a cell cluster thermal model of the battery pack based on the obtained cell partitions; and interacting the cell cluster thermal model with a second-order RC equivalent circuit model to establish the thermoelectric coupling model.

[0085] In an exemplary embodiment, the modeling module is further configured to: determine the temperature distribution of the battery pack during operation; and divide the battery cells of the battery pack into a central heat-generating zone and a peripheral heat-generating zone based on the temperature distribution, wherein the central heat-generating zone and the peripheral heat-generating zone are connected by thermal resistance.

[0086] In an exemplary embodiment, the modeling module is further configured to: establish a cell heat generation model corresponding to the cell through the cell partition, and establish a cell heat dissipation model corresponding to the cell through the cell partition; and determine the cell cluster thermal model through the cell heat generation model and the cell heat dissipation model.

[0087] In an exemplary embodiment, the modeling module is further configured to: calculate a first heat generation in the central heat generation zone using the target principle, and calculate a second heat generation in the peripheral heat generation zone using the target principle, wherein the cell partition includes: the central heat generation zone and the peripheral heat generation zone; and determine the cell heat generation model using the first heat generation and the second heat generation.

[0088] In an exemplary embodiment, the modeling module is further configured to: determine the heat exchange between a first part and a second part of the battery pack, wherein the first part is any part among all parts of the battery pack, the second part is an adjacent part of the any part among other parts, the other parts being all parts other than the any part, and the all parts including at least the cell partitions. The heat exchange determines the cell heat dissipation model.

[0089] In an exemplary embodiment, the modeling module is further configured to: perform charge-discharge tests on the battery pack based on orthogonal experiments to obtain a feature scenario dataset of the battery pack under each feature scenario, wherein each feature scenario is a scenario obtained by combining multiple target scenarios, including: temperature scenario, power scenario, thermal management state scenario, and vehicle state scenario; identify parameters of the feature scenario dataset using the least squares method to determine the optimal parameters of the cell cluster thermal model under each feature scenario; and determine the cell cluster thermal model using the optimal parameters.

[0090] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when run.

[0091] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0092] S1, obtain the operating current of the vehicle's battery pack, wherein the operating current includes at least: charging current and discharging current;

[0093] S2, The operating current is input into the thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack, wherein the thermoelectric coupling model is a model established by partitioning the cells of the battery pack through the temperature distribution of the battery pack during operation.

[0094] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0095] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0096] Embodiments of this application also provide a computer program product, including a computer program, wherein the computer program, when executed by a processor, performs the steps in any of the above method embodiments.

[0097] Embodiments of this application also provide an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0098] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0099] S1, obtain the operating current of the vehicle's battery pack, wherein the operating current includes at least: charging current and discharging current;

[0100] S2, The operating current is input into the thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack, wherein the thermoelectric coupling model is a model established by partitioning the cells of the battery pack through the temperature distribution of the battery pack during operation.

[0101] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0102] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0103] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0104] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for determining a temperature state, characterized in that, Applied to vehicles, including: The operating current of the vehicle's battery pack is obtained, wherein the operating current includes at least: charging current and discharging current; The operating current is input into a thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack. The thermoelectric coupling model is established by partitioning the cells of the battery pack based on the temperature distribution of the battery pack during operation.

2. The method according to claim 1, characterized in that, Before inputting the operating current into a thermoelectric coupling model deployed in the vehicle's battery management system to determine the temperature state of the battery pack, the method further includes: The battery cells of the battery pack are partitioned by the temperature distribution of the battery pack during operation, and a thermal model of the battery cell cluster of the battery pack is established by the obtained cell partitioning. The thermal model of the battery cell cluster is interacted with the second-order RC equivalent circuit model to establish the thermoelectric coupling model.

3. The method according to claim 2, characterized in that, The battery cells of the battery pack are partitioned based on the temperature distribution during operation, including: Determine the temperature distribution of the battery pack during operation; The battery pack cells are divided into a central heat-generating zone and a peripheral heat-generating zone based on the temperature distribution, wherein the central heat-generating zone and the peripheral heat-generating zone are connected by thermal resistance.

4. The method according to claim 2, characterized in that, A cell cluster thermal model of the battery pack is established based on the obtained cell partitions, including: A cell heat generation model and a cell heat dissipation model are established for the corresponding cell by means of the cell partitioning. The thermal model of the battery cell cluster is determined by the battery cell heat generation model and the battery cell heat dissipation model.

5. The method according to claim 4, characterized in that, Establishing a cell heat generation model corresponding to the cell through the cell partitioning includes: The first heat generation in the central heat generation zone is calculated using the target principle, and the second heat generation in the peripheral heat generation zone is calculated using the target principle, wherein the cell partition includes: the central heat generation zone and the peripheral heat generation zone; The cell heat generation model is determined by the first heat generation and the second heat generation.

6. The method according to claim 4, characterized in that, Establishing a cell heat dissipation model corresponding to the cell through the cell partitioning includes: Determine the heat exchange between a first part and a second part of the battery pack, wherein the first part is any part of all parts of the battery pack, the second part is an adjacent part of the any part in other parts, the other parts are all parts except the any part, and all parts include at least: the cell partition; The heat exchange process is used to determine the cell's heat dissipation model.

7. The method according to claim 4, characterized in that, The cell cluster thermal model is determined by the cell heat generation model and the cell heat dissipation model, including: The battery pack was charged and discharged based on orthogonal experiments to obtain a feature scenario dataset of the battery pack under each feature scenario. Each feature scenario is a scenario obtained by combining multiple target scenarios, including: temperature scenario, power scenario, thermal management status scenario, and vehicle status scenario. The parameters of the cell cluster thermal model are identified by using the least squares method to determine the optimal parameters for each feature scenario. The optimal parameters are used to determine the thermal model of the battery cell cluster.

8. A system for determining temperature state, characterized in that, Applied to vehicles, including: An acquisition module is used to acquire the operating current of the vehicle's battery pack, wherein the operating current includes at least: charging current and discharging current; A determination module is used to input the operating current into a thermoelectric coupling model deployed in the battery management system of the vehicle to determine the temperature state of the battery pack. The thermoelectric coupling model is a model established by partitioning the cells of the battery pack based on the temperature distribution of the battery pack during operation.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program, when executed, performs the method of any one of claims 1 to 7.

10. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method of any one of claims 1 to 7 through the computer program.

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