Battery cooling method, device and vehicle

Abstract

The embodiment of the present application relates to the technical field of vehicles, and discloses a battery cooling method, a battery cooling device and a vehicle, the battery cooling method comprising: inputting at least two first preset battery temperature difference values into a battery temperature prediction model respectively to obtain at least two battery maximum temperatures. The battery temperature difference value is the difference between the real-time battery temperature of the target battery at the current moment and the cooling liquid temperature corresponding to the target battery. The battery maximum temperature is the highest temperature among the real-time battery temperatures at multiple moments in a charging period. Interpolation calculation is performed based on the at least two first preset battery temperature difference values and the at least two battery maximum temperatures to obtain a target temperature difference value corresponding to a preset battery temperature threshold. Based on the target temperature difference value, a target cooling liquid temperature is determined. Based on the target cooling liquid temperature, the cooling system of the target battery is controlled to cool the target battery. In this way, the battery can be cooled.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically to a battery cooling method, apparatus, and vehicle. Background Technology

[0002] Batteries generate a significant amount of heat during charging and discharging. If this heat cannot be dissipated in time, the internal temperature of the battery will rise sharply, accelerating the aging of the positive and negative electrode materials and the decomposition of the electrolyte, thus shortening the battery's lifespan.

[0003] Therefore, how to cool the battery so that it operates within its normal operating range and extends its lifespan has become a pressing technical problem that needs to be solved. Summary of the Invention

[0004] In view of the above shortcomings, the purpose of this application is to provide a battery cooling method, apparatus and vehicle, which aims to solve the technical problem of how to cool the battery.

[0005] In a first aspect, embodiments of this application provide a battery cooling method, which includes: inputting at least two first preset battery temperature difference values ​​into a battery temperature prediction model to obtain at least two maximum battery temperatures. The battery temperature difference is the difference between the real-time battery temperature of the target battery at the current moment and the corresponding coolant temperature of the target battery. The battery temperature prediction model is used to predict the real-time battery temperature of the target battery at multiple moments during a charging cycle. The maximum battery temperature is the highest temperature among the real-time battery temperatures at multiple moments during the charging cycle. Based on the at least two first preset battery temperature difference values ​​and the at least two maximum battery temperatures, interpolation calculations are performed to obtain a target temperature difference value corresponding to a preset battery temperature threshold. Based on the target temperature difference value, a target coolant temperature is determined. Based on the target coolant temperature, the cooling system of the target battery is controlled to cool the target battery.

[0006] Since the battery temperature difference characterizes the real-time temperature difference between the target battery and the coolant temperature, and this temperature difference directly affects the efficiency of the coolant in removing heat, by setting at least two different first preset battery temperature differences and obtaining the corresponding maximum battery temperatures, a correspondence between the temperature difference and the maximum battery temperature can be established, resulting in at least two maximum battery temperatures. Interpolating the at least two first preset battery temperature differences and the corresponding at least two maximum battery temperatures allows for mathematical fitting among finite discrete data points, yielding the target temperature difference corresponding to the preset battery temperature threshold. This provides a target value that meets the accuracy requirements without requiring extensive additional experiments or simulations. Since the target temperature difference is the critical temperature difference that causes the maximum battery temperature to reach the preset battery temperature threshold, the coolant temperature derived from this target temperature difference is the coolant temperature value required to control the maximum battery temperature near the preset threshold. In this way, when the cooling system operates at this temperature, it can cool the battery, keeping the highest temperature of the battery during charging and discharging near the desired target temperature threshold. This helps ensure that the battery operates within a suitable temperature range, thereby avoiding energy waste caused by over-cooling or high-temperature aging of the battery caused by insufficient cooling. At the same time, this control process does not rely on human experience to set cooling parameters, which helps improve the accuracy and adaptability of cooling control.

[0007] In one possible embodiment, interpolation calculation is performed based on at least two first preset battery temperature differences and at least two maximum battery temperatures to obtain a target temperature difference corresponding to a preset battery temperature threshold. This includes: determining a target linear interpolation relationship based on at least two first preset battery temperature differences and at least two maximum battery temperatures; and determining the target temperature difference corresponding to the preset battery temperature threshold based on the target linear interpolation relationship.

[0008] Since the first preset battery temperature difference and the battery's maximum temperature exhibit an approximately linear variation within a certain range, linear interpolation can be used to fit this variation. This allows for the construction of a target linear interpolation relationship between the temperature difference and the maximum temperature using fewer discrete data points. Furthermore, because this target linear interpolation relationship is a mathematical expression reflecting the correspondence between temperature difference and temperature, derived from the fitting of actual data points, the preset temperature difference obtained by reverse engineering this relationship is the critical temperature difference value corresponding to the battery's maximum temperature reaching the preset battery temperature threshold. This allows for the rapid acquisition of the target temperature difference value without adding additional experimental or simulation samples, thus reducing computational costs and data processing time.

[0009] In one possible embodiment, the battery cooling method further includes: inputting a target temperature difference into a battery temperature prediction model to obtain the highest battery temperature corresponding to the target temperature difference; inputting at least one second preset battery temperature difference into the battery temperature prediction model to obtain the highest battery temperature corresponding to at least one second preset battery temperature difference; performing interpolation calculations based on the highest battery temperature corresponding to the target temperature difference and the highest battery temperature corresponding to at least one second preset battery temperature difference to obtain an updated target temperature difference; determining an updated target coolant temperature based on the updated target temperature difference; and controlling the cooling system of the target battery to cool the target battery based on the updated target coolant temperature.

[0010] The target temperature difference and the second preset battery temperature difference are both known discrete data points. Inputting them into the battery temperature prediction model yields their respective temperature prediction results: the maximum battery temperature corresponding to the target temperature difference and the maximum battery temperature corresponding to at least one second preset battery temperature difference. Since the target temperature difference before the update was obtained by interpolating from the initial preset data points, using the target temperature difference before the update as a new data point for re-interpolation results in an updated target temperature difference. This is equivalent to adding a model-validated data node to the original interpolation interval. This node is closer to the true correspondence between temperature difference and temperature than the initial preset difference. Therefore, the updated target temperature difference obtained after re-interpolation has higher accuracy than the original, which helps reduce the deviation caused by the sparsity of the initial data points or linear fitting errors. Subsequently, the updated target coolant temperature can be determined based on the updated target temperature difference, and the cooling system can be controlled to cool the target battery based on the updated target coolant temperature. Since the updated target coolant temperature is derived from a more accurate target temperature difference, the cooling system, when operating according to the updated temperature value, can more accurately control the battery's maximum temperature near the preset battery temperature threshold, thereby further improving the accuracy of cooling control.

[0011] In one possible embodiment, the battery temperature prediction model includes: a first battery temperature prediction model corresponding to a low-temperature battery region and a second battery temperature prediction model corresponding to a high-temperature battery region. The first battery temperature prediction model is used to determine the outlet temperature of the coolant after it flows through the low-temperature battery region. The second battery temperature prediction model is used to determine the battery temperature of the high-temperature battery region. At least two first preset battery temperature differences are input into the battery temperature prediction models to obtain at least two maximum battery temperatures, including: for any one of the at least two first preset battery temperature differences, inputting the first preset battery temperature difference into the first battery temperature prediction model to obtain the high-temperature coolant temperature corresponding to the high-temperature battery region, thus obtaining at least one high-temperature coolant temperature. For any one of the at least one high-temperature coolant temperatures, inputting the high-temperature coolant temperature into the second battery temperature prediction model to obtain the maximum battery temperature corresponding to the high-temperature coolant temperature, thus obtaining at least two maximum battery temperatures.

[0012] A first battery temperature prediction model and a second battery temperature prediction model are established for the low-temperature battery region and the high-temperature battery region, respectively. The first battery temperature prediction model can accurately calculate the temperature rise of the coolant after it flows through the low-temperature region, based on the relatively stable heat exchange in the low-temperature region, thus providing a reliable coolant inlet temperature for the high-temperature region. Multiple preset battery temperature differences are input into the first battery temperature prediction model to obtain multiple high-temperature coolant temperatures, covering thermal state information under various preset temperature difference conditions, thus providing multiple sets of independent input data for subsequent predictions. Each high-temperature coolant temperature is input into the second battery temperature prediction model. Since the second battery temperature prediction model is specifically modeled for heat accumulation and heat dissipation conditions in the high-temperature region, it can accurately reflect the peak temperature change trend in this region, thus obtaining the highest battery temperature corresponding to each preset temperature difference value. The first battery temperature prediction model and the second battery temperature prediction model are responsible for calculating the coolant temperature rise and the battery peak temperature, respectively. The input-output relationship between the two is clear, allowing the parameters of each model to be independently calibrated and verified, thereby improving the reliability and operability of the overall prediction process.

[0013] In one possible embodiment, the first battery temperature prediction model satisfies the following formula: .

[0014] in; T1 represents the battery heat capacity corresponding to the low-temperature battery region; T1 represents the temperature of the low-temperature battery region; t represents time; I represents the charging current of the target battery; R1 represents the internal resistance of the low-temperature battery region; T3 represents the coolant temperature corresponding to the low-temperature battery region; T5 represents the ambient temperature of the target battery; A1 represents the heat transfer coefficient between the low-temperature battery region and the coolant; A3 represents the heat transfer coefficient between the low-temperature battery region and the environment of the target battery.

[0015] This formula includes the heat generation term of the low-temperature battery region, the heat exchange term between the low-temperature battery region and the coolant, and the heat exchange term between the low-temperature battery region and the environment of the target battery. It can comprehensively reflect the heat balance relationship of the low-temperature battery region, thereby improving the accuracy of the first battery temperature prediction model in predicting the temperature change of the low-temperature battery region.

[0016] In one possible embodiment, the second battery temperature prediction model satisfies the following formula: .

[0017] in; T1 represents the battery heat capacity corresponding to the high-temperature battery region; T2 represents the temperature of the high-temperature battery region; R2 represents the internal resistance of the high-temperature battery region; T4 represents the coolant temperature corresponding to the high-temperature battery region; T5 represents the ambient temperature of the target battery; A2 represents the heat transfer coefficient between the high-temperature battery region and the coolant; A4 represents the heat transfer coefficient between the high-temperature battery region and the environment of the target battery.

[0018] The formula includes heat generation terms in the high-temperature battery region, heat exchange terms between the high-temperature battery region and the coolant, and heat exchange terms between the high-temperature battery region and the target battery environment. It can comprehensively reflect the heat balance relationship in the high-temperature battery region, thereby improving the accuracy of the second battery temperature prediction model in predicting temperature changes in the high-temperature battery region.

[0019] In one possible embodiment, the coolant temperature corresponding to the high-temperature battery region is determined based on the following method: .

[0020] Where T4 represents the coolant temperature corresponding to the high-temperature battery region; and T3 represents the coolant temperature corresponding to the low-temperature battery region. A1 is used to represent the heat capacity of the coolant flowing through the target battery per unit time; A1 is used to represent the heat transfer coefficient between the low-temperature battery region and the coolant.

[0021] The formula is based on the coolant temperature corresponding to the low-temperature battery region, the heat capacity of the coolant flowing through the target battery per unit time, and the heat transfer coefficient and temperature difference between the low-temperature battery region and the coolant. It can reflect the temperature change of the coolant as it flows from the low-temperature battery region to the high-temperature battery region, thus providing the coolant temperature input value corresponding to the high-temperature battery region for the second battery temperature prediction model.

[0022] In one possible embodiment, determining the target coolant temperature based on the target temperature difference includes: determining the target coolant temperature based on the real-time battery temperature of the target battery at the current moment and the target temperature difference. The target coolant temperature is the difference between the real-time battery temperature of the target battery and the target temperature difference.

[0023] The target coolant temperature is the difference between the real-time battery temperature and the target temperature difference. The target temperature difference represents the temperature difference between the battery temperature and the coolant temperature required for the battery to reach the preset battery temperature threshold. Therefore, by subtracting the target temperature difference from the current real-time battery temperature, the coolant temperature required to achieve the target temperature difference in the current state can be calculated in reverse, thus realizing the quantitative determination of the target coolant temperature.

[0024] In one possible embodiment, after determining the target coolant temperature based on the target temperature difference, the battery cooling method further includes: controlling the cooling system of the target battery to turn on when the target battery temperature difference is greater than or equal to a first preset difference threshold; and controlling the cooling system of the target battery to turn off when the target battery temperature difference is less than or equal to a second preset difference threshold.

[0025] If the target battery temperature difference is greater than or equal to the first preset threshold, it indicates a large target battery temperature difference. A large target battery temperature difference indicates a high demand for temperature difference between the battery and coolant, meaning the battery is currently under a high heat load. Activating the air conditioning system in this case lowers the ambient temperature around the target battery, increasing the heat exchange temperature difference between the battery and the environment. This assists in cooling the target battery through environmental heat exchange, further improving the overall cooling effect on top of coolant cooling. If the target battery temperature difference is less than or equal to the second preset threshold, it indicates a small target battery temperature difference. A small target battery temperature difference indicates a low current cooling demand. The battery temperature can be maintained within a reasonable range without continuous operation of the cooling system. Turning off the cooling system in this case avoids energy consumption caused by coolant circulation and the continuous operation of related components, thus helping to reduce overall vehicle energy consumption.

[0026] In one possible embodiment, the parameters of the battery temperature prediction model are determined by performing parameter identification on the battery temperature prediction model to obtain the parameters of the battery temperature prediction model.

[0027] Parameter identification is achieved by comparing the output of the battery temperature prediction model with the measured data and adjusting the model parameters until they match. Therefore, the parameters of the battery temperature prediction model obtained after parameter identification can make the output of the battery temperature prediction model closer to the actual temperature change of the target battery under actual working conditions, thereby improving the prediction accuracy of the battery temperature prediction model.

[0028] Secondly, this application provides a battery cooling device, comprising: a battery maximum temperature determination module, a target temperature difference determination module, a coolant temperature determination module, and a battery cooling control module. The battery maximum temperature determination module is used to input at least two first preset battery temperature differences into a battery temperature prediction model to obtain at least two battery maximum temperatures. The battery temperature difference is the difference between the real-time battery temperature of the target battery at the current moment and the corresponding coolant temperature of the target battery. The battery temperature prediction model is used to predict the real-time battery temperature of the target battery at multiple moments during a charging cycle. The battery maximum temperature is the highest temperature among the real-time battery temperatures at multiple moments during a charging cycle. The target temperature difference determination module is used to perform interpolation calculations based on at least two first preset battery temperature differences and at least two battery maximum temperatures to obtain a target temperature difference corresponding to a preset battery temperature threshold. The coolant temperature determination module is used to determine the target coolant temperature based on the target temperature difference. The battery cooling control module is used to control the cooling system of the target battery to cool the target battery based on the target coolant temperature.

[0029] Thirdly, this application provides a vehicle that includes a battery cooling device as described in the second aspect. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0031] Figure 1 This is a schematic diagram of the structure of a battery cooling control system disclosed in an embodiment of this application; Figure 2 This is a schematic flowchart of a battery cooling method disclosed in an embodiment of this application; Figure 3 This is a schematic diagram illustrating an example of a secant method disclosed in an embodiment of this application; Figure 4 This is a schematic diagram illustrating an example of battery heat exchange disclosed in an embodiment of this application; Figure 5 This is a schematic flowchart illustrating a battery variation curve disclosed in an embodiment of this application; Figure 6 This is a schematic flowchart illustrating another battery variation curve disclosed in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a battery cooling device disclosed in an embodiment of this application; Figure 8 This is a schematic diagram of another battery cooling device disclosed in an embodiment of this application. Detailed Implementation

[0032] The terms “first,” “second,” etc., are used for descriptive purposes only and have no sequential or technical meaning, nor should they be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0033] In the embodiments of this application, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0034] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include other steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or device.

[0035] Furthermore, in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplarily" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplarily" or "for example" is intended to present concepts in a concrete manner.

[0036] The implementation environment of the embodiments of this application is described below.

[0037] For example, such as Figure 1 The diagram shows a schematic representation of a battery cooling control system. This system includes a battery cooling control device 1, a cooling system 2, a battery 3, and a temperature sensor 4. The battery cooling control device 1 is connected to the cooling system 2, the battery 3, and the temperature sensor 4.

[0038] The battery cooling control device 1 can be a controller in the vehicle or a battery management system. The vehicle can be, but is not limited to, a pure electric vehicle, a hybrid vehicle, a range-extended electric vehicle, a plug-in hybrid vehicle, or a new energy vehicle. This application embodiment does not limit the specific form of the vehicle. Alternatively, the battery cooling control device 1 can also be an external server connected to the vehicle, or a server cluster consisting of multiple external servers. In some implementations, the server cluster can be a distributed cluster server. This application embodiment does not impose any limitations in this regard.

[0039] Battery 3 can be a power battery pack in a vehicle. Alternatively, battery 3 can be an external mobile energy storage unit detachably connected to the vehicle, or a battery pack system composed of multiple battery modules; this application embodiment does not impose any limitations on this. Cooling system 2 can be a liquid cooling system in a vehicle, including coolant circulation pipes, a water pump, a radiator, and other components; alternatively, cooling system 2 can be a direct-cooling thermal management system or an immersion cooling system; this application embodiment does not impose any limitations on this. Temperature sensor 4 is used to collect the real-time battery temperature and coolant temperature of battery 3.

[0040] In this embodiment, the battery cooling control device 1 is used to input at least two preset battery temperature difference values ​​into a battery temperature prediction model to obtain at least two maximum battery temperatures. The battery temperature difference is the difference between the real-time battery temperature and the coolant temperature of the target battery 3 at the current moment. The battery temperature prediction model is used to predict the real-time battery temperature of the target battery 3 at multiple moments during a charging cycle; the maximum battery temperature is the highest temperature among the real-time battery temperatures at multiple moments during the charging cycle. The battery cooling control device 1 is also used to perform interpolation calculations based on the at least two preset battery temperature difference values ​​and the at least two maximum battery temperatures to obtain a target temperature difference value corresponding to a preset battery temperature threshold. The battery cooling control device 1 is also used to determine a target coolant temperature based on the target temperature difference value. The battery cooling control device 1 is also used to generate a cooling control command based on the target coolant temperature and send the cooling control command to the cooling system 2. The cooling control command includes the target coolant temperature value at the next moment.

[0041] In this embodiment of the application, the cooling system 2 is used to execute the target coolant temperature value at the next moment in response to receiving a cooling control command, so as to adjust the temperature of the target battery 3.

[0042] In this embodiment, the temperature sensor 4 is used to collect the real-time battery temperature and coolant temperature of the target battery 3 at the current moment, and send the collected temperature data to the battery cooling control device 1.

[0043] Specifically, since the battery temperature difference represents the temperature difference between the real-time battery temperature of the target battery 3 and the coolant temperature at the current moment, and this temperature difference directly affects the efficiency of the coolant in removing heat, by setting at least two different preset battery temperature differences, the battery cooling control device 1 can obtain the corresponding maximum battery temperature, thus constructing a correspondence between the temperature difference and the maximum battery temperature, and obtaining at least two maximum battery temperatures. By interpolating the at least two preset battery temperature differences and the corresponding at least two maximum battery temperatures, mathematical fitting can be performed between a limited number of discrete data points to obtain the target temperature difference corresponding to the preset battery temperature threshold. This yields a target value that meets the accuracy requirements without requiring a large number of additional experiments or simulations. Since the target temperature difference is the critical temperature difference that makes the maximum temperature of battery 3 reach the preset battery temperature threshold, the coolant temperature derived by the battery cooling control device 1 based on this target temperature difference is the coolant temperature value required to control the maximum temperature of battery 3 near the preset threshold. In this way, after the cooling system 2 operates at this temperature, it can cool the battery 3, so that the highest temperature of the battery 3 during the charging and discharging process is controlled near the desired target temperature threshold. This helps to ensure that the battery 3 works within a suitable temperature range, thereby avoiding energy waste caused by over-cooling or high-temperature aging of the battery 3 caused by insufficient cooling. At the same time, this control process does not rely on human experience to set cooling parameters, which helps to improve the accuracy and adaptability of cooling control.

[0044] It should be noted that the system architecture and application scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0045] The battery cooling method provided in this application can be applied to a battery cooling device, specifically to the processor of that device. This application uses the execution of the battery cooling method by the battery cooling device as an example to illustrate the battery cooling method provided in this application.

[0046] like Figure 2 As shown, this application provides a battery cooling method, which includes: S101. Input at least two first preset battery temperature differences into the battery temperature prediction model to obtain at least two battery maximum temperatures.

[0047] The battery temperature difference is the difference between the real-time battery temperature of the target battery and the corresponding coolant temperature at the current moment. The coolant temperature is the temperature of the coolant at the battery inlet. During charging, the coolant flows through the battery at a temperature lower than the battery temperature, continuously carrying away the heat generated by the battery. Subtracting the current real-time battery temperature from the current coolant temperature yields a positive temperature difference value, i.e., the battery temperature difference. The battery temperature prediction model is used to predict the real-time battery temperature of the target battery at multiple moments during the charging cycle. Using the battery temperature estimation model, the temperature change over time during charging can be calculated under given coolant temperature conditions. The maximum battery temperature is the highest of the real-time battery temperatures at multiple moments during the charging cycle.

[0048] As one possible implementation, S101 includes: for each of the at least two first preset battery temperature differences, acquiring the battery's state of charge data, and inputting the battery's state of charge data and the first preset battery temperature difference into a battery temperature prediction model to obtain the battery's maximum temperature, thereby obtaining at least two battery maximum temperatures.

[0049] The charging status data includes at least one of the following: charging current, ambient temperature of the target battery, and state of charge of the target battery. The charging current is the smaller value between the charging system capability and the charging capability of the target battery. The charging system capability is the maximum charging current value that the charging system (such as a charging pile or on-board charger) can provide, and the charging capability of the target battery is the maximum allowable charging current value of the target battery.

[0050] As one possible implementation, the charging capacity of the target battery can be determined in the following ways: The charging capacity, i.e., the maximum allowable charging current, can be obtained from the target battery's temperature and state of charge. For example, the charging capacity can be obtained by looking up a pre-stored map table of the battery cooling device using the battery's state of charge and maximum and minimum temperatures as indexes. Alternatively, the charging capacity can be determined by establishing a mathematical model of the battery to simulate its internal state. The specific charging capacity of the battery can be calculated based on the battery's state; this application does not limit the method used to obtain the battery's charging capacity.

[0051] The battery temperature prediction model calculates the changes in real-time battery temperature and state of charge (SOC) throughout the charging process using a time-progression approach. The charging process is divided into several equal-length time steps. Starting from the initial moment, using the current real-time battery temperature, SOC, and charging current, the model calculates the battery temperature and SOC after one time step using the established heat balance relationship. The calculated result is then used as the initial value for the next time step, and this process is repeated to obtain the relationship between real-time battery temperature and SOC over time during the entire charging process, providing a data foundation for optimizing subsequent cooling strategies.

[0052] For details on how to input at least two first preset battery temperature differences into the battery temperature prediction model to obtain at least two maximum battery temperatures, please refer to S201-S202.

[0053] S102. Based on at least two first preset battery temperature differences and at least two battery maximum temperatures, interpolation calculation is performed to obtain the target temperature difference corresponding to the preset battery temperature threshold.

[0054] The preset battery temperature threshold refers to the highest temperature the target battery is allowed to reach during charging. Setting the preset battery temperature threshold requires comprehensive consideration of factors such as battery safety requirements, cycle life characteristics, and charging efficiency. For example, a preset battery temperature threshold of 45°C is set based on the highest temperature allowed by the battery's charging and discharging capabilities. Alternatively, to protect the battery's aging characteristics, the preset battery temperature threshold can be set to 35°C; or, to reduce the target battery's energy consumption, the preset battery temperature threshold can be set to 50°C. The specific value of the preset battery temperature threshold can be set according to the actual usage scenario; this application does not limit the specific value of the preset battery temperature threshold.

[0055] For details on how to calculate the target temperature difference corresponding to the preset battery temperature threshold by interpolation based on at least two first preset battery temperature differences and at least two battery maximum temperatures, please refer to S201-S202.

[0056] S103. Determine the target coolant temperature based on the target temperature difference.

[0057] As a feasible implementation method, S103 includes: determining the target coolant temperature based on the difference between the real-time battery temperature of the target battery and the target temperature at the current moment. The target coolant temperature is the difference between the real-time battery temperature of the target battery and the target temperature.

[0058] The target coolant temperature is the difference between the real-time battery temperature and the target temperature difference. The target temperature difference represents the temperature difference between the battery temperature and the coolant temperature required for the battery to reach the preset battery temperature threshold. Therefore, by subtracting the target temperature difference from the current real-time battery temperature, the coolant temperature required to achieve the target temperature difference in the current state can be calculated in reverse, thus realizing the quantitative determination of the target coolant temperature.

[0059] S104. Based on the target coolant temperature, control the cooling system of the target battery to cool the target battery.

[0060] As one possible implementation, S104 includes: generating a temperature adjustment command based on the target coolant temperature; sending the temperature adjustment command to the cooling system of the target battery to control the cooling system of the target battery to cool the target battery; the temperature adjustment command is used to instruct the cooling system to adjust the coolant temperature corresponding to the target battery at the current moment to the target coolant temperature.

[0061] In this way, during the battery charging process, the battery temperature is controlled below a certain value by using a certain cooling water temperature.

[0062] In some embodiments, due to the physical properties of the coolant used in the battery cooling circuit and the limitation of the maximum cooling capacity of the cooling system, the coolant temperature cannot be reduced or increased indefinitely. Therefore, it is necessary to limit the calculated target coolant temperature. For example, the lower limit of the target coolant temperature can be set to 16°C and the upper limit to 35°C. That is, when the calculated target coolant temperature is lower than 16°C, 16°C is used as the actual control target; when the calculated target coolant temperature is higher than 35°C, 35°C is used as the actual control target.

[0063] As can be seen from S101-S104, the solution provided in this application embodiment, since the battery temperature difference characterizes the temperature difference relationship between the real-time battery temperature and the coolant temperature of the target battery at the current moment, and this temperature difference relationship directly affects the efficiency of the coolant in removing heat, can construct a correspondence between the temperature difference and the battery's maximum temperature by setting at least two different first preset battery temperature differences and obtaining the corresponding maximum battery temperature, thus obtaining at least two maximum battery temperatures. By interpolating the at least two first preset battery temperature differences and the corresponding at least two maximum battery temperatures, mathematical fitting can be performed between a limited number of discrete data points to obtain the target temperature difference corresponding to the preset battery temperature threshold, thus obtaining a target value that meets the accuracy requirements without adding a large amount of additional experiments or simulation calculations. Since the target temperature difference is the critical temperature difference value that makes the battery's maximum temperature reach the preset battery temperature threshold, the coolant temperature derived from this target temperature difference is the coolant temperature value required to control the battery's maximum temperature near the preset threshold. In this way, when the cooling system operates at this temperature, it can cool the battery, keeping the highest temperature of the battery during charging and discharging near the desired target temperature threshold. This helps ensure that the battery operates within a suitable temperature range, thereby avoiding energy waste caused by over-cooling or high-temperature aging of the battery caused by insufficient cooling. At the same time, this control process does not rely on human experience to set cooling parameters, which helps improve the accuracy and adaptability of cooling control.

[0064] In some embodiments, after obtaining at least two first preset battery temperature differences and at least two battery maximum temperatures, since there is an approximately linear variation law between the preset battery temperature differences and the battery maximum temperatures within a certain range, it is necessary to establish a linear relationship between at least two first preset battery temperature differences and at least two battery maximum temperatures, so as to obtain the target temperature difference corresponding to the preset battery temperature threshold.

[0065] As a feasible implementation method, S102 includes: S201. Determine the target linear interpolation relationship based on at least two first preset battery temperature differences and at least two battery maximum temperatures.

[0066] The target linear interpolation relationship is a linear function correspondence determined based on at least two preset battery temperature differences and at least two corresponding maximum battery temperatures. The preset battery temperature difference and the maximum battery temperature can be considered approximately linear within a certain range; that is, for every unit change in the preset battery temperature difference, the maximum battery temperature changes by a roughly fixed amount. Based on at least two preset battery temperature differences and their corresponding maximum battery temperatures, at least two sets of data points can be constructed. The preset battery temperature difference and the maximum battery temperature in each set of data points constitute the two coordinate components of that data point. In a planar coordinate system, a straight line can be determined through at least two data points; this straight line is the target linear interpolation relationship.

[0067] S202. Based on the target linear interpolation relationship, determine the target temperature difference corresponding to the preset battery temperature threshold.

[0068] As one possible implementation, S202 includes: substituting a preset battery temperature threshold into a target linear interpolation relationship, and calculating the target temperature difference corresponding to the preset battery temperature threshold through the target linear interpolation relationship.

[0069] For example, at the start of charging, before iterative calculations have been performed and the target temperature difference corresponding to the preset battery temperature threshold has been obtained, the initial temperature of the target battery is 0. In this case, two different first preset battery temperature differences can be given as initial iteration values, denoted as Tw1 and Tw2 respectively. Tw1 is 0℃, and Tw2 is 0.1℃. Tw1 and Tw2 are input into the battery temperature prediction model respectively to calculate their corresponding maximum battery temperature. The maximum battery temperature corresponding to Tw1 is denoted as Tb1, and the maximum battery temperature corresponding to Tw2 is denoted as Tb2. Figure 3 As shown, with the battery temperature difference as the x-axis and the battery's highest temperature as the y-axis, two coordinate points (Tw1, Tb1) and (Tw2, Tb2) can be obtained. A straight line can be determined based on these two coordinate points. The preset y-axis value of this line corresponding to the preset battery temperature threshold is used as the target temperature difference value.

[0070] As can be seen from S201-S202, the solution provided by this application embodiment exhibits an approximately linear variation law between the first preset battery temperature difference and the battery's maximum temperature within a certain range. By using linear interpolation to fit this variation law, a target linear interpolation relationship between the temperature difference and the maximum temperature can be constructed with fewer discrete data points. Furthermore, since this target linear interpolation relationship is a mathematical expression that reflects the correspondence between temperature difference and temperature, obtained by fitting actual data points, the preset temperature difference derived from this target linear interpolation relationship is the critical temperature difference value corresponding to the battery's maximum temperature reaching the preset battery temperature threshold. This allows for the rapid acquisition of the target temperature difference value without adding additional experimental or simulation samples, which helps reduce computational costs and data processing time.

[0071] In some embodiments, since the maximum battery temperature varies with the battery temperature difference, the larger the temperature difference, the lower the maximum battery temperature. By inputting different cooling water temperatures into the battery temperature prediction model, the model will output different maximum charging temperatures. Therefore, it can be inferred that there exists a cooling water temperature such that the maximum charging temperature output by the model at this temperature is exactly equal to a pre-set target temperature. To find this specific cooling water temperature, Newton's tangent method can be used for iterative solution.

[0072] Furthermore, during charging, the real-time temperature and state of charge of the target battery continuously change over time. Therefore, the target temperature difference calculated at the current moment is only applicable to the current state, and needs to be recalculated after the state changes at the next moment. At each moment, based on the real-time temperature and state of charge of the target battery, an interpolation calculation using the secant method is performed to obtain the target temperature difference for the current moment, and this target temperature difference is output as the calculation result for the current moment for cooling control. Since the interval between two adjacent moments is short and the battery state changes little, the difference between the target temperature difference required at the current moment and the next moment is also relatively small. Therefore, at the next moment, based on the calculation result of the current moment, another interpolation calculation using the secant method can be performed to obtain the updated target temperature difference. Throughout the entire charging process, only one secant method interpolation calculation is performed at each moment, the computational load is controllable, and the calculated value always follows the state change during the continuous state change, maintaining a target temperature difference that matches the current state.

[0073] As a feasible approach, battery cooling methods also include: S301. Input the target temperature difference into the battery temperature prediction model to obtain the highest battery temperature corresponding to the target temperature difference.

[0074] During charging, if the target temperature difference has already been calculated once through interpolation at the current moment, there is no need to start the calculation from the initial value again at the next moment. Since the temperature and state of charge of the battery change little between adjacent moments, the calculation result at the previous moment is very close to the result required for the next moment. Therefore, the calculated value at the previous moment can be used as the initial input for the next moment, and another interpolation calculation can be performed to obtain the updated target temperature difference for the next moment. For the implementation of S301, please refer to the detailed description of S101; it will not be elaborated upon here.

[0075] S302. Input at least one second preset battery temperature difference into the battery temperature prediction model to obtain the highest battery temperature corresponding to at least one second preset battery temperature difference.

[0076] Since this application uses the secant method to determine and update the target temperature difference, and the secant method requires at least two points to determine a straight line, an adjacent point of the target temperature difference is needed to jointly construct a linear interpolation relationship. The difference between the second preset battery temperature difference and the target temperature difference is a preset offset. The preset battery temperature difference is generated using this preset offset to ensure that the target temperature difference and the second preset battery temperature difference are sufficiently close, so that the slope of the straight line can reflect the local change trend near the target point. For the implementation of S302, please refer to the detailed description of S101; this application will not repeat it here.

[0077] For details on the implementation of S101, please refer to the specific description of S101; this application will not elaborate further here.

[0078] S302. Based on the highest battery temperature corresponding to the target temperature difference and the highest battery temperature corresponding to at least one second preset battery temperature difference, interpolation calculation is performed to obtain the updated target temperature difference.

[0079] For example, Newton's iteration method is used for iterative solution. Starting from the beginning of charging, 0 is used as the initial value of the inlet temperature. According to the update rule of Newton's iteration method, the inlet temperature of the next step is calculated from the inlet temperature of the current iteration step, and this value is continuously updated throughout the charging process, which can realize dynamic tracking and real-time control of the optimal inlet temperature.

[0080] For details on the implementation of S302, please refer to the specific description of S102; this application will not elaborate further here.

[0081] S303. Based on the updated target temperature difference, determine the updated target coolant temperature.

[0082] For details on the implementation of S303, please refer to the specific description of S103; this application will not elaborate further here.

[0083] S304. Based on the updated target coolant temperature, control the cooling system of the target battery to cool the target battery.

[0084] For details on the implementation of S304, please refer to the specific description of S104; this application will not elaborate further here.

[0085] In this embodiment, a battery temperature prediction model is used to estimate the changes in battery temperature and state of charge during the charging process in real time. Based on the battery temperature prediction model, by changing the cooling water temperature input to the model, the predicted results of battery temperature and state of charge under different cooling conditions can be obtained. Therefore, using this battery temperature prediction model, through iterative calculation, the cooling water temperature that makes the maximum battery temperature equal to a preset battery temperature threshold can be obtained. Using this cooling water temperature as the control target temperature of the battery cooling system, the temperature control effect of the battery charging process can be achieved. Therefore, this application can dynamically optimize the battery charging cooling process in real time based on the idea of ​​recursive iteration, with time series recursion as the core concept, to achieve effective control of battery temperature. While achieving real-time tracking of the optimal water temperature during the charging process with a small amount of computation, it is computationally friendly to the vehicle embedded controller and does not lose calculation accuracy.

[0086] As can be seen from S301-S304, in the solution provided by this application embodiment, the target temperature difference and the second preset battery temperature difference are both known discrete data points. Inputting these into the battery temperature prediction model respectively yields the corresponding temperature prediction results, namely, the highest battery temperature corresponding to the target temperature difference and the highest battery temperature corresponding to at least one second preset battery temperature difference. Since the target temperature difference before the update is obtained by interpolation of the initial preset data points, and the target temperature difference before the update is used as a new data point to participate in the interpolation calculation again, the updated target temperature difference is equivalent to adding a model-validated data node within the original interpolation interval. This node is closer to the true correspondence between temperature difference and temperature than the initial preset difference. Therefore, the updated target temperature difference obtained after re-interpolation has higher accuracy than the previous one, which helps to reduce the deviation caused by the sparsity of the initial data points or linear fitting errors. Subsequently, the updated target coolant temperature can be determined based on the updated target temperature difference, and the cooling system can be controlled to cool the target battery based on the updated target coolant temperature. Since the updated target coolant temperature is derived from a more accurate target temperature difference, the cooling system, when operating according to the updated temperature value, can more accurately control the battery's maximum temperature near the preset battery temperature threshold, thereby further improving the accuracy of cooling control.

[0087] In some embodiments, the target battery includes multiple battery cells, which can be simplified into a first battery cell representing a temperature less than or equal to a preset lower temperature threshold and a second battery cell representing a temperature greater than or equal to a preset upper temperature threshold. The first battery cell corresponds to a low-temperature battery region, and the second battery cell corresponds to a high-temperature battery region. The preset lower temperature threshold can be the lowest temperature among the multiple battery cell temperatures at the same time, or it can be a pre-given fixed temperature value, such as 19°C, 22°C, 23°C, 24°C, or 25°C. The preset upper temperature threshold can be the highest temperature among the multiple battery cell temperatures at the same time, or it can be a pre-given fixed temperature value, such as 40°C, 41°C, 42°C, 43°C, or 45°C. This application does not limit the preset lower temperature threshold and the preset upper temperature threshold.

[0088] As a feasible implementation method, the battery temperature prediction model includes: a first battery temperature prediction model corresponding to the low-temperature battery region and a second battery temperature prediction model corresponding to the high-temperature battery region. The first battery temperature prediction model is used to determine the outlet temperature of the coolant after it flows through the low-temperature battery region. The second battery temperature prediction model is used to determine the battery temperature in the high-temperature battery region. S101 includes: S401. For any one of the at least two first preset battery temperature differences, input the first preset battery temperature difference into the first battery temperature prediction model to obtain the high temperature coolant temperature corresponding to the high temperature battery region, so as to obtain at least one high temperature coolant temperature.

[0089] The first preset battery temperature difference is used to characterize the heat transfer driving force between the low-temperature battery region and the high-temperature battery region. This driving force directly affects the heat flow rate transferred from the low-temperature battery region to the high-temperature battery region, thereby changing the heat share of the low-temperature battery region used to heat the coolant. By substituting the first preset battery temperature difference as a known boundary condition into the heat balance equation of the low-temperature battery region, the temperature change trend of the low-temperature battery region under the influence of this heat transfer flow can be determined. Based on this, the heat absorbed by the coolant during its flow through the low-temperature battery region can be calculated. This heat is converted into a temperature rise in the coolant and added to the inlet temperature to obtain the outlet temperature of the coolant after it has flowed through the low-temperature battery region. Since the coolant flows through the low-temperature battery region and the high-temperature battery region sequentially in the physical flow path, this outlet temperature is the inlet temperature of the coolant before it enters the high-temperature battery region, and therefore it is determined as the coolant temperature corresponding to the high-temperature battery region.

[0090] As one possible implementation, S401 inputs the first preset battery temperature difference into the first battery temperature prediction model to obtain the high-temperature coolant temperature corresponding to the high-temperature battery region, including: inputting the battery charging state data and the first preset battery temperature difference into the first battery temperature prediction model to obtain the high-temperature coolant temperature corresponding to the high-temperature battery region.

[0091] One possible approach is to construct a battery temperature prediction model based on the relationship between enthalpy change, heat generation from battery internal resistance, heat exchange from coolant, and heat dissipation from the environment. Specifically, the temperature change in the low-temperature battery region is proportional to the enthalpy change in that region per unit time, and the temperature change in the high-temperature battery region is proportional to the enthalpy change in that region per unit time.

[0092] As a feasible approach, the first battery temperature prediction model satisfies Formula 1.

[0093] Formula 1.

[0094] in, T1 represents the battery thermal capacity corresponding to the low-temperature battery region; t represents time; I represents the charging current of the target battery; R1 represents the internal resistance of the low-temperature battery region. T3 is used to represent the heat generated per unit time by the internal resistance of the battery in the low-temperature battery region; T3 is used to represent the coolant temperature corresponding to the low-temperature battery region, that is, the temperature of the coolant at the battery inlet. A1 represents the heat transfer coefficient between the low-temperature battery region and the coolant; A3 represents the heat transfer coefficient between the low-temperature battery region and the target battery's environment; T5 represents the ambient temperature of the target battery. Used to represent the amount of heat dissipated from the environment per unit time in a low-temperature battery region.

[0095] In this embodiment, the ambient temperature of the target battery and the temperature of the low-temperature battery region can be acquired by sensors. The internal resistance of the low-temperature battery region can be obtained directly through experiments or material property parameters. The battery heat capacity corresponding to the low-temperature battery region, the heat transfer coefficient between the low-temperature battery region and the coolant, and the heat transfer coefficient between the low-temperature battery region and the environment of the target battery are unknown parameters and need to be identified and obtained in advance through experiments.

[0096] As a feasible implementation method, the parameters of the battery temperature prediction model are determined as follows: the parameters of the battery temperature prediction model are obtained by parameter identification.

[0097] The method for parameter identification of the battery temperature prediction model can be the least squares method, particle swarm optimization algorithm, or recursive least squares method. The method for parameter identification of the battery temperature prediction model can be set according to the actual situation. This application does not restrict the parameter identification method.

[0098] Specifically, charging experiments can be conducted on automotive power batteries. During the experiment, electronic components collect battery state data such as the temperature of the low-temperature battery region, the corresponding coolant temperature, charging current, and time. Using the collected battery state data, the least squares method is employed to identify the parameters of the first battery temperature prediction model. This allows the unknown parameters to be obtained, including the battery heat capacity corresponding to the low-temperature battery region, the heat transfer coefficient between the low-temperature battery region and the coolant, and the heat transfer coefficient between the low-temperature battery region and the target battery's environment.

[0099] Parameter identification is achieved by comparing the output of the battery temperature prediction model with measured data and adjusting the model parameters until they match. Therefore, the parameters of the battery temperature prediction model obtained after parameter identification enable the output of the battery temperature prediction model to more closely reflect the actual temperature changes of the target battery under actual operating conditions, thereby improving the prediction accuracy of the battery temperature prediction model.

[0100] Formula 1 includes the heat generation term of the low-temperature battery region, the heat exchange term between the low-temperature battery region and the coolant, and the heat exchange term between the low-temperature battery region and the environment of the target battery. It can comprehensively reflect the heat balance relationship of the low-temperature battery region, which is conducive to improving the accuracy of the first battery temperature prediction model in predicting the temperature change of the low-temperature battery region.

[0101] S402. For any one of the high-temperature coolant temperatures, input the high-temperature coolant temperature into the second battery temperature prediction model to obtain the highest battery temperature corresponding to the high-temperature coolant temperature, so as to obtain at least two battery highest temperatures.

[0102] The high-temperature coolant temperature, as the initial temperature of the cooling medium before entering the high-temperature battery region, determines the baseline capacity of the coolant to remove heat per unit time in this region. That is, the higher the coolant inlet temperature, the smaller the temperature difference between the coolant and the battery, the less convective heat transfer, the more heat accumulates within the battery itself, and the higher the peak temperature. The high-temperature coolant temperature is input as a known boundary condition into the second battery temperature prediction model. This model calculates the heat accumulation in the high-temperature battery region under given cooling conditions based on the heat generation rate and heat dissipation conditions. This heat accumulation is then superimposed with the initial temperature of the region to obtain the peak temperature of that region under the corresponding cooling conditions. This peak temperature is determined as the highest battery temperature corresponding to the high-temperature coolant temperature.

[0103] As a feasible implementation method, the second battery temperature prediction model satisfies the following formula 2.

[0104] Formula 2.

[0105] in, T1 represents the battery heat capacity corresponding to the high-temperature battery region; T2 represents the temperature of the high-temperature battery region; R2 represents the internal resistance of the high-temperature battery region. T4 is used to represent the heat generated per unit time by the internal resistance of the battery in the high-temperature battery region; T5 is used to represent the coolant temperature corresponding to the high-temperature battery region, i.e., the outlet temperature of the battery pack cooling circuit; T5 is used to represent the ambient temperature of the target battery; A2 is used to represent the heat transfer coefficient between the high-temperature battery region and the coolant. A4 is used to represent the heat transfer of coolant per unit time in the high-temperature battery region; A4 is used to represent the heat transfer coefficient between the high-temperature battery region and the environment of the target battery. Used to represent the amount of heat dissipated from the environment per unit time in a high-temperature battery region.

[0106] The method for obtaining the parameters of the second battery temperature prediction model can refer to the method for obtaining the parameters of the first battery temperature prediction model, and will not be elaborated here.

[0107] Formula 2 includes the heat generation term of the high-temperature battery region, the heat exchange term between the high-temperature battery region and the coolant, and the heat exchange term between the high-temperature battery region and the environment of the target battery. It can comprehensively reflect the heat balance relationship of the high-temperature battery region, which is conducive to improving the accuracy of the second battery temperature prediction model in predicting the temperature change of the high-temperature battery region.

[0108] As can be seen from S401-S402, the solution provided in this application establishes a first battery temperature prediction model and a second battery temperature prediction model for the low-temperature battery region and the high-temperature battery region, respectively. The first battery temperature prediction model can accurately calculate the temperature rise of the coolant after it flows through the low-temperature region, based on the relatively stable heat exchange characteristics of the low-temperature region, thus providing a reliable coolant inlet temperature for the high-temperature region. Multiple first preset battery temperature differences are input into the first battery temperature prediction model to obtain multiple high-temperature coolant temperatures, covering thermal state information under various preset temperature difference conditions, thus providing multiple sets of independent input data for subsequent predictions. Each high-temperature coolant temperature is input into the second battery temperature prediction model. Since the second battery temperature prediction model specifically models the heat accumulation and heat dissipation conditions in the high-temperature region, it can accurately reflect the peak temperature change trend of this region, thus obtaining the highest battery temperature corresponding to each preset temperature difference value. The first battery temperature prediction model and the second battery temperature prediction model respectively undertake the functions of coolant temperature rise calculation and battery peak temperature calculation. The input-output relationship between the two is clear, allowing the parameters of each model to be independently calibrated and verified, thereby improving the reliability and operability of the overall prediction process.

[0109] In some embodiments, such as Figure 4 As shown, during the charging and discharging process, the target battery will generate Joule heat (i.e., I) due to its internal resistance. 2 To maintain the battery within its optimal safe operating temperature range, the target battery can dissipate heat through two heat exchange paths. One is through the cooling system, where the coolant at a lower temperature exchanges heat with the target battery surface, and the rate at which the coolant removes heat satisfies Equation 3. The other is through natural convection or radiation heat exchange with the ambient air surrounding the target battery, and the heat exchange rate satisfies Equation 4. In other words, by establishing a heat balance equation that includes both heat generation and heat dissipation paths, the dynamic temperature changes of the target battery can be calculated. Therefore, using Equations 3 and 4, a first battery temperature prediction model and a second battery temperature prediction model can be established.

[0110] Formula 3.

[0111] in; Used to represent the heat exchanged between the coolant and the target battery; Used to represent a unit of time; Used to represent the heat exchanged between the coolant and the battery per unit time; Used to represent the heat transfer coefficient between the target battery and the coolant; Used to indicate the real-time temperature of the target battery; Used to indicate the temperature of the coolant flowing through the target battery.

[0112] Formula 4.

[0113] in; Used to represent the heat exchanged between the target battery and the external natural environment; Used to represent the heat exchanged between the target battery and the external natural environment per unit time; Used to represent the heat transfer coefficient between the target battery and the external natural environment; Used to indicate the temperature of the external natural environment.

[0114] In some embodiments, when both an inlet temperature sensor and an outlet temperature sensor are provided in the cooling circuit, the measured values ​​of the coolant temperature corresponding to the low-temperature battery region and the coolant temperature corresponding to the high-temperature battery region can be directly acquired without additional calculation. When the cooling circuit is only equipped with an inlet temperature sensor, the inlet water temperature is used as the coolant temperature corresponding to the low-temperature battery region, while the coolant temperature corresponding to the high-temperature battery region is obtained through calculation.

[0115] Specifically, after flowing in from the inlet, the coolant first passes through the low-temperature battery region, where it exchanges heat with the low-temperature battery region, causing a change in its enthalpy. Based on the relationship between this change in enthalpy and the heat capacity of the coolant flowing through the target battery per unit time, the temperature rise of the coolant after flowing through the low-temperature battery region is calculated. Then, the coolant temperature corresponding to the high-temperature battery region when the coolant reaches the vicinity of the high-temperature battery region is deduced from the coolant temperature corresponding to the low-temperature battery region.

[0116] As a feasible approach, the coolant temperature corresponding to the high-temperature battery region satisfies Formula 5.

[0117] Formula 5.

[0118] Where T4 represents the coolant temperature corresponding to the high-temperature battery region; and T3 represents the coolant temperature corresponding to the low-temperature battery region. A1 is used to represent the heat capacity of the coolant flowing through the target battery per unit time. A1 is used to represent the heat transfer coefficient between the low-temperature battery region and the coolant.

[0119] One possible approach is to determine the heat capacity of the coolant flowing through the target battery per unit time by multiplying the coolant flow rate, coolant density, and coolant specific heat capacity. The coolant flow rate, coolant density, and coolant specific heat capacity can be obtained from material property data.

[0120] Formula 5 is determined based on the coolant temperature corresponding to the low-temperature battery region, the heat capacity of the coolant flowing through the target battery per unit time, and the heat transfer coefficient and temperature difference between the low-temperature battery region and the coolant. It can reflect the temperature change of the coolant as it flows from the low-temperature battery region to the high-temperature battery region, thus providing the input value of the coolant temperature corresponding to the high-temperature battery region for the second battery temperature prediction model.

[0121] In other embodiments, when the cooling circuit is equipped only with an outlet temperature sensor, the outlet water temperature can be used as the coolant temperature corresponding to the high-temperature battery region, while the coolant temperature corresponding to the low-temperature battery region is obtained through reverse calculation. Specifically, based on the enthalpy difference between the coolant temperature corresponding to the high-temperature battery region and the temperature of the high-temperature battery region, combined with the heat capacity of the coolant flowing through the target battery per unit time, the temperature of the coolant before flowing through the low-temperature battery region can be calculated, i.e., the coolant temperature corresponding to the low-temperature battery region.

[0122] For the method of calculating the coolant temperature corresponding to the low-temperature battery region, please refer to the introduction of the calculation method for the coolant temperature corresponding to the high-temperature battery region. This application will not elaborate on this.

[0123] In some embodiments, after the identified parameters have been obtained, the calculation steps and parameters of the differential equation can be written into the battery cooling device. A calculation program for the first function is designed in the battery cooling device, and an iterative algorithm is set in the program to calculate the target coolant temperature required in real time.

[0124] In some embodiments, during the actual operation of the battery temperature prediction model, starting from the temperature of the low-temperature battery region and the temperature of the high-temperature battery region at the beginning of charging, the temperature of the low-temperature battery region and the temperature of the high-temperature battery region at each subsequent moment can be calculated step by step according to a set time step, thereby obtaining dynamic change data of battery temperature throughout the entire charging process.

[0125] In some embodiments, the capacity of the cooling system can be utilized effectively, and the temperature of the target battery can be controlled according to the battery's temperature rise characteristics and the power supply capacity of the charging system. The timing of battery cooling activation can be automatically identified; the coolant system will not be activated when the target battery does not require cooling, and the air conditioning system will assist in cooling the battery when cooling is needed.

[0126] As a feasible implementation method, after executing S203, the battery cooling method also includes: S501. When the temperature difference of the target battery is greater than or equal to the first preset difference threshold, control the cooling system of the target battery to be turned on.

[0127] In some embodiments, after the cooling system of the target battery is turned on, the air conditioning compressor is started to cool the target battery.

[0128] The first preset difference threshold can be 10℃, 11℃, 12℃, 13℃, or 14℃. The specific setting of the first preset difference threshold can be set according to the actual situation. This application does not limit the specific value of the first preset difference threshold. For example, when the first preset difference threshold is 10℃, a signal is sent to control the cooling system to start cooling, and cooling control is performed based on the target coolant temperature.

[0129] S502. When the temperature difference of the target battery is less than or equal to the second preset difference threshold, control the cooling system of the target battery to shut down.

[0130] The second preset difference threshold can be 4℃, 5℃, 6℃, 7℃, or 8℃. The specific setting of the second preset difference threshold can be set according to the actual situation. This application does not limit the specific value of the second preset difference threshold. For example, during the battery cooling process, when the second preset difference threshold is 8℃, the cooling system is controlled to shut down.

[0131] As can be seen from S501-S502, the solution provided in this application indicates that the target battery temperature difference is large when it is greater than or equal to the first preset difference threshold. Since a large target battery temperature difference indicates a high temperature difference requirement between the battery and coolant, and a high current heat load on the battery, turning on the air conditioning system can lower the ambient temperature around the target battery, increasing the heat exchange temperature difference between the battery and the environment. This assists in heat dissipation of the target battery through environmental heat exchange, further improving the overall cooling effect on top of coolant cooling. Conversely, when the target battery temperature difference is less than or equal to the second preset difference threshold, the target battery temperature difference is small. Since a small target battery temperature difference indicates a low current cooling requirement, the battery temperature can be maintained within a reasonable range without continuous operation of the cooling system. Turning off the cooling system avoids energy consumption caused by coolant circulation and the continuous operation of related components, thus helping to reduce overall vehicle energy consumption.

[0132] In some embodiments, the time step for iterative calculations can be set according to the computing power of the battery cooling control device. A shorter time step indicates more iterations per unit time, resulting in a larger computational load; a longer time step indicates fewer iterations per unit time, resulting in a smaller computational load. Therefore, a suitable time step can be calibrated based on the computing power of the battery cooling control device to achieve a balance between computational accuracy and system resource consumption.

[0133] In practical applications, vehicle cooling systems may have varying cooling capacities. When the actual cooling capacity of the vehicle's cooling system reaches the target coolant temperature calculated in this solution, the actual battery temperature will change according to the trajectory predicted by the model, with its maximum temperature not exceeding the preset target temperature value. For example... Figure 5 and Figure 6 As shown, the curves depicting the changes in the target battery's minimum temperature, maximum temperature, coolant temperature, and target coolant temperature are presented. Figure 5 Approximately 241 seconds after charging begins, the system determines, based on real-time calculations, that the cooling activation conditions have been met and initiates the cooling system. Thereafter, the battery temperature is stably maintained below the target temperature. Even when the vehicle's actual cooling capacity cannot reach the target coolant temperature calculated by this system, it can still control the cooling system to operate at maximum capacity, delaying battery temperature rise as much as possible within the limits of hardware capabilities to protect battery safety. Figure 6 In this case, the cooling system operates at maximum cooling power throughout the entire charging process.

[0134] The foregoing mainly describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the battery cooling device includes corresponding hardware structures and / or software modules for performing each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0135] This application embodiment can divide the battery cooling device into functional modules according to the above method. For example, the battery cooling device may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. The module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0136] Reference Figure 7 The battery cooling device includes a battery maximum temperature determination module 7001, a target temperature difference determination module 7002, a coolant temperature determination module 7003, and a battery cooling control module 7004.

[0137] The battery maximum temperature determination module 7001 is used to input at least two first preset battery temperature difference values ​​into the battery temperature prediction model to obtain at least two battery maximum temperatures. The battery temperature difference is the difference between the real-time battery temperature of the target battery at the current moment and the corresponding coolant temperature of the target battery. The battery temperature prediction model is used to predict the real-time battery temperature of the target battery at multiple moments during a charging cycle. The battery maximum temperature is the highest temperature among the real-time battery temperatures at multiple moments during a charging cycle.

[0138] The target temperature difference determination module 7002 is used to perform interpolation calculations based on at least two first preset battery temperature differences and at least two battery maximum temperatures to obtain the target temperature difference corresponding to the preset battery temperature threshold.

[0139] The coolant temperature determination module 7003 is used to determine the target coolant temperature based on the target temperature difference.

[0140] The battery cooling control module 7004 is used to control the cooling system of the target battery to cool the target battery based on the target coolant temperature.

[0141] In some embodiments, the battery cooling device further includes: a target linear interpolation relationship determination module. The target linear interpolation relationship determination module is used to determine a target linear interpolation relationship based on at least two first preset battery temperature differences and at least two maximum battery temperatures. The target temperature difference determination module is used to determine a target temperature difference corresponding to a preset battery temperature threshold based on the target linear interpolation relationship.

[0142] In some embodiments, the battery maximum temperature determination module is used to input a target temperature difference and at least one second preset battery temperature difference into a battery temperature prediction model to obtain the battery maximum temperature corresponding to the target temperature difference and the battery maximum temperature corresponding to at least one second preset battery temperature difference. The target temperature difference determination module is used to perform interpolation calculations based on the battery maximum temperature corresponding to the target temperature difference and the battery maximum temperature corresponding to at least one second preset battery temperature difference to obtain an updated target temperature difference. The coolant temperature determination module is used to determine an updated target coolant temperature based on the updated target temperature difference. The battery cooling control module is used to control the cooling system of the target battery to cool the target battery based on the updated target coolant temperature.

[0143] In some embodiments, the battery temperature prediction model includes: a first battery temperature prediction model corresponding to a low-temperature battery region and a second battery temperature prediction model corresponding to a high-temperature battery region. The first battery temperature prediction model is used to determine the temperature change of the coolant after it flows through the target battery. The second battery temperature prediction model is used to determine the maximum temperature of the target battery. The maximum battery temperature determination module is used to input any one of at least two first preset battery temperature differences into the first battery temperature prediction model to obtain the high-temperature coolant temperature corresponding to the high-temperature battery region, so as to obtain at least one high-temperature coolant temperature. The maximum battery temperature determination module is further used to input any one of the at least one high-temperature coolant temperatures into the second battery temperature prediction model to obtain the maximum battery temperature corresponding to the high-temperature coolant temperature, so as to obtain at least two maximum battery temperatures.

[0144] In some embodiments, the first battery temperature prediction model satisfies the following formula: .

[0145] in; T1 represents the battery heat capacity corresponding to the low-temperature battery region; T1 represents the temperature of the low-temperature battery region; t represents time; I represents the charging current of the target battery; R1 represents the internal resistance of the low-temperature battery region; T3 represents the coolant temperature corresponding to the low-temperature battery region; T5 represents the ambient temperature of the target battery; A1 represents the heat transfer coefficient between the low-temperature battery region and the coolant; A3 represents the heat transfer coefficient between the low-temperature battery region and the environment of the target battery.

[0146] In some embodiments, the second battery temperature prediction model satisfies the following formula: .

[0147] in; T1 represents the battery heat capacity corresponding to the high-temperature battery region; T2 represents the temperature of the high-temperature battery region; R2 represents the internal resistance of the high-temperature battery region; T4 represents the coolant temperature corresponding to the high-temperature battery region; T5 represents the ambient temperature of the target battery; A2 represents the heat transfer coefficient between the high-temperature battery region and the coolant; A4 represents the heat transfer coefficient between the high-temperature battery region and the environment of the target battery.

[0148] In some embodiments, the coolant temperature corresponding to the high-temperature battery region is determined based on the following: .

[0149] Where T4 represents the coolant temperature corresponding to the high-temperature battery region; and T3 represents the coolant temperature corresponding to the low-temperature battery region. A1 is used to represent the heat capacity of the coolant flowing through the target battery per unit time. A1 is used to represent the heat transfer coefficient between the low-temperature battery region and the coolant.

[0150] In some embodiments, the battery cooling device further includes a coolant temperature determination module, configured to determine a target coolant temperature based on the real-time battery temperature of the target battery and a target temperature difference at the current moment. The target coolant temperature is the difference between the real-time battery temperature of the target battery and the target temperature difference.

[0151] In some embodiments, the battery cooling device further includes a cooling system control module. After determining the target coolant temperature based on the target temperature difference, the cooling system control module is configured to control the cooling system of the target battery to turn on when the target battery temperature difference is greater than or equal to a first preset difference threshold. The cooling system control module is further configured to control the cooling system of the target battery to turn off when the target battery temperature difference is less than or equal to a second preset difference threshold.

[0152] In some embodiments, the battery cooling device further includes a parameter identification module. The parameter identification module is used to identify parameters of the battery temperature prediction model to obtain the parameters of the battery temperature prediction model.

[0153] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0154] In an exemplary embodiment, this application also provides a computing device, which may include a processor and a memory. The processor may be a computing cluster composed of multiple computing nodes, and the memory may adopt a distributed memory architecture. The processor integrated into the computing device is configured to execute the battery cooling method of any of the above embodiments.

[0155] Figure 8 This is a schematic diagram of another battery cooling device provided in an embodiment of this application. Figure 8 As shown, the battery cooling device includes: one or more memories 820, one or more processors 810, a communication bus 840, and a communication interface 830. The processors 810 and memories 820 are connected via the communication bus 840; the one or more memories 820 are used to store computer program code, which includes computer instructions; when the one or more processors 810 execute the computer instructions, the computing device performs the battery cooling method provided in this embodiment.

[0156] Optionally, the memory 820 may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc., and the embodiments of this application do not impose any restrictions on this.

[0157] The processor 810 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof, and the embodiments of this application do not impose any limitations on this.

[0158] The communication bus 840 can be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus, etc. This communication bus 840 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 It is represented by a single thick line, but this does not mean that there is only one bus or one type of communication bus.

[0159] The communication interface 830 uses any transceiver-like device for communicating with other devices or communication networks, such as control systems, radio access networks (RAN), wireless local area networks (WLAN), etc.

[0160] This application also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be executed by computer instructions instructing related hardware; exemplarily, the related hardware can be a processor of a computing device. The program instructions can be stored in the above-described computer-readable storage medium, and when executed, the processes of the above method embodiments can be implemented. The computer-readable storage medium can be memory. The above-described computer-readable storage medium can also be an external storage device, such as a hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. Further, the above-described computer-readable storage medium can include both memory and external storage devices. The above-described computer-readable storage medium is used to store the above-described computer program instructions and other programs and data required by the above-described battery cooling method.

[0161] This application also provides a vehicle that can perform the methods described in the above embodiments via a battery cooling device.

[0162] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0163] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

[0164] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery cooling method, characterized in that, The battery cooling method includes: At least two first preset battery temperature difference values ​​are input into the battery temperature prediction model to obtain at least two maximum battery temperatures; the battery temperature difference is the difference between the real-time battery temperature of the target battery at the current moment and the coolant temperature corresponding to the target battery; the battery temperature prediction model is used to predict the real-time battery temperature of the target battery at multiple moments during the charging cycle; the maximum battery temperature is the highest temperature among the real-time battery temperatures at multiple moments during the charging cycle. Based on the at least two first preset battery temperature differences and the at least two battery maximum temperatures, interpolation calculations are performed to obtain the target temperature difference corresponding to the preset battery temperature threshold. Based on the target temperature difference, the target coolant temperature is determined; Based on the target coolant temperature, the cooling system of the target battery is controlled to cool the target battery.

2. The battery cooling method according to claim 1, characterized in that, The step of interpolating based on the at least two first preset battery temperature differences and the at least two battery maximum temperatures to obtain the target temperature difference corresponding to the preset battery temperature threshold includes: Based on the temperature difference between the at least two first preset batteries and the highest temperature of the at least two batteries, a target linear interpolation relationship is determined. Based on the target linear interpolation relationship, the preset temperature difference corresponding to the preset battery temperature threshold is determined as the target temperature difference.

3. The battery cooling method according to claim 1 or 2, characterized in that, The battery cooling method further includes: Input the target temperature difference into the battery temperature prediction model to obtain the highest battery temperature corresponding to the target temperature difference; Input at least one second preset battery temperature difference into the battery temperature prediction model to obtain the highest battery temperature corresponding to the at least one second preset battery temperature difference; The updated target temperature difference is obtained by interpolation calculation based on the highest battery temperature corresponding to the target temperature difference and the highest battery temperature corresponding to the at least one second preset battery temperature difference. Based on the updated target temperature difference, the updated target coolant temperature is determined; Based on the updated target coolant temperature, the cooling system of the target battery is controlled to cool the target battery.

4. The battery cooling method according to claim 1, characterized in that, The battery temperature prediction model includes: a first battery temperature prediction model corresponding to the low-temperature battery region and a second battery temperature prediction model corresponding to the high-temperature battery region; the first battery temperature prediction model is used to determine the outlet temperature of the coolant after it flows through the low-temperature battery region; the second battery temperature prediction model is used to determine the battery temperature of the high-temperature battery region. The step of inputting at least two first preset battery temperature differences into the battery temperature prediction model to obtain at least two maximum battery temperatures includes: For any one of the at least two first preset battery temperature differences, the first preset battery temperature difference is input into the first battery temperature prediction model to obtain the high temperature coolant temperature corresponding to the high temperature battery region, so as to obtain at least one high temperature coolant temperature. For any one of the at least one high-temperature coolant temperatures, the high-temperature coolant temperature is input into the second battery temperature prediction model to obtain the highest battery temperature corresponding to the high-temperature coolant temperature, so as to obtain the highest temperatures of the at least two batteries.

5. The battery cooling method according to claim 4, characterized in that, The first battery temperature prediction model satisfies the following formula: ; in; T1 is used to represent the battery thermal capacity corresponding to the low-temperature battery region; T1 is used to represent the temperature of the low-temperature battery region. t represents time; I represents the charging current of the target battery; R1 represents the internal resistance of the low-temperature battery region; T3 represents the coolant temperature corresponding to the low-temperature battery region; T5 represents the ambient temperature of the target battery; A1 represents the heat transfer coefficient between the low-temperature battery region and the coolant; A3 represents the heat transfer coefficient between the low-temperature battery region and the environment of the target battery.

6. The battery cooling method according to claim 4, characterized in that, The second battery temperature prediction model satisfies the following formula: ; in; T1 represents the battery heat capacity corresponding to the high-temperature battery region; T2 represents the temperature of the high-temperature battery region; R2 represents the internal resistance of the high-temperature battery region; T4 represents the coolant temperature corresponding to the high-temperature battery region; T5 represents the ambient temperature of the target battery; A2 represents the heat transfer coefficient between the high-temperature battery region and the coolant; A4 represents the heat transfer coefficient between the high-temperature battery region and the environment of the target battery.

7. The battery cooling method according to claim 5 or 6, characterized in that, The coolant temperature corresponding to the high-temperature battery region is determined based on the following method: ; in; T4 represents the coolant temperature corresponding to the high-temperature battery region; T3 represents the coolant temperature corresponding to the low-temperature battery region. A1 is used to represent the heat capacity of the coolant flowing through the target battery per unit time; A1 is used to represent the heat transfer coefficient between the low-temperature battery region and the coolant.

8. The battery cooling method according to claim 1, characterized in that, Determining the target coolant temperature based on the target temperature difference includes: Obtain the real-time battery temperature of the target battery; The target coolant temperature is determined based on the difference between the real-time battery temperature of the target battery at the current moment and the target temperature; the target coolant temperature is the difference between the real-time battery temperature of the target battery and the target temperature.

9. The battery cooling method according to claim 1, characterized in that, After determining the target coolant temperature based on the target temperature difference, the battery cooling method further includes: If the temperature difference of the target battery is greater than or equal to the first preset difference threshold, the cooling system of the target battery is turned on. If the temperature difference of the target battery is less than or equal to a second preset difference threshold, the cooling system of the target battery is controlled to shut down.

10. The battery cooling method according to claim 1, characterized in that, The parameters of the battery temperature prediction model are determined in the following way: The parameters of the battery temperature prediction model are obtained by parameter identification.

11. A battery cooling device, characterized in that, The battery cooling device includes: a battery maximum temperature determination module, a target temperature difference determination module, a coolant temperature determination module, and a battery cooling control module; The battery maximum temperature determination module is used to input at least two first preset battery temperature difference values ​​into the battery temperature prediction model to obtain at least two battery maximum temperatures; the battery temperature difference value is the difference between the real-time battery temperature of the target battery at the current moment and the coolant temperature corresponding to the target battery; the battery temperature prediction model is used to predict the real-time battery temperature of the target battery at multiple moments during the charging cycle; the battery maximum temperature is the highest temperature among the real-time battery temperatures at multiple moments during the charging cycle. The target temperature difference determination module is used to perform interpolation calculations based on the at least two first preset battery temperature differences and the at least two battery maximum temperatures to obtain the target temperature difference corresponding to the preset battery temperature threshold. The coolant temperature determination module is used to determine the target coolant temperature based on the target temperature difference. The battery cooling control module is used to control the cooling system of the target battery to cool the target battery based on the target coolant temperature.

12. A vehicle, characterized in that, The vehicle includes the battery cooling device as described in claim 11.

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