Battery module temperature acquisition method, device and storage medium

Abstract

The present invention discloses a method, device, and storage medium for obtaining the temperature of a battery module, which can improve the accuracy of the obtained module temperature. The method part includes: obtaining the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature; performing outlier rejection processing on the sampling point temperatures of each battery module according to the sampling point temperatures of multiple sampling points of each battery module to obtain the target sampling temperature of each battery module; obtaining the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature; and determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular, to a method, device, and storage medium for obtaining the temperature of a battery module. Background Art

[0002] The module temperature information of a battery module is one of the most basic information required for function controls such as battery state monitoring and charging control. Therefore, it is crucial to obtain an accurate or effectively true module temperature. Currently, the mainstream module temperature sampling principle is as follows: temperature sensors (usually NTCs) arranged on the busbar, module end plate, or cell connection piece sense temperature changes, and the resistance values of the temperature sensors are different at different temperatures; then, the resistance value of the current temperature sensor is calculated based on the divided voltage, and the module temperature is obtained by looking up the table according to the resistance value.

[0003] The inventor found that when the battery module is operating, the highest temperature of the module is usually at the busbar or connection piece. Heat is conducted from the busbar to the nickel sheet, and it takes a certain amount of time for the temperature of the temperature sensor to reach the module temperature value, that is, there is a certain hysteresis, which will affect the value detected by the temperature sensor. Eventually, this hysteresis will cause the obtained module temperature to deviate from the true value, resulting in low accuracy of the obtained module temperature. Summary of the Invention

[0004] The present invention provides a method, device, and storage medium for obtaining the temperature of a battery module to solve the technical problem of low accuracy of the module temperature obtained by the traditional solution.

[0005] In a first aspect, a method for obtaining the temperature of a battery module is provided, including:

[0006] Obtaining the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature;

[0007] Performing outlier rejection processing on the sampling point temperatures of each battery module according to the sampling point temperatures of multiple sampling points of each battery module to obtain the target sampling temperature of each battery module;

[0008] Obtaining the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature;

[0009] Determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

[0010] In a possible implementation, the performing outlier rejection processing on the sampling point temperatures of each battery module according to the sampling point temperatures of multiple sampling points of each battery module to obtain the target sampling temperature of each battery module includes:

[0011] Determine the average temperature of all the battery modules based on the sampling point temperatures of multiple sampling points of each battery module;

[0012] Determine the outlier temperature extreme value and the outlier temperature mean error corresponding to the battery pack;

[0013] Based on the outlier temperature extreme value, the outlier temperature mean error, and the average temperature, determine whether there is an outlier temperature among the sampling point temperatures of multiple sampling points of each battery module;

[0014] If there is an outlier temperature, eliminate the outlier temperature of each battery module, and determine the target sampling temperature of each battery module based on the non-outlier temperatures of each battery module;

[0015] If there is no outlier temperature, determine the target sampling temperature of each battery module based on the sampling point temperatures of multiple sampling points of each battery module.

[0016] In a possible implementation, the determining whether there is an outlier temperature among the sampling point temperatures of multiple sampling points of each battery module based on the outlier temperature extreme value, the outlier temperature mean error, and the average temperature includes:

[0017] If it is determined that the sampling point temperature of the battery module is greater than or equal to the high-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is greater than or equal to the high-temperature outlier mean error, and the duration is longer than a preset duration, then it is determined that the battery module has a high-temperature outlier temperature;

[0018] If it is determined that the sampling point temperature of the battery module is less than or equal to the low-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is less than or equal to the low-temperature outlier mean error, and the duration is longer than the preset duration, then it is determined that the battery module has a low-temperature outlier temperature.

[0019] In a possible implementation, the obtaining the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature includes:

[0020] Pre-construct a thermal equilibrium equation corresponding to the battery module in the z direction, where the z direction corresponds to the height direction of the module battery cells;

[0021] Through the thermal equilibrium equation, obtain the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature;

[0022] The thermal equilibrium equation is:

[0023] Among them, Q f = A * ((T balance ||z = 0) - T am ) * h, (Tbalance ||z = 0) = T real_ij ;

[0024] The cell_height is the height of the battery cells in the battery module, s is the area of the module cells, Q is the heat generation of the battery cells in the battery module, h is the convective heat transfer coefficient between the module cells and the environment, A is the convective heat transfer coefficient inside the module cells, and T am is the ambient temperature, and T real_ij is the target sampling temperature at the j-th sampling point of the i-th battery module, and T balance is the thermal equilibrium temperature.

[0025] In a possible implementation, determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature includes:

[0026] Determining the respective weights of the thermal equilibrium temperature and the target sampling temperature according to the current current and the ambient temperature;

[0027] Determining the module temperature of the battery module according to the thermal equilibrium temperature, the target sampling temperature, and their respective weights.

[0028] In a possible implementation, determining the module temperature of the battery module according to the thermal equilibrium temperature, the target sampling temperature, and their respective weights includes:

[0029] Determining the module temperature of the battery module through the following formula:

[0030] T BMS = ε * T real_ij +(1 - ε) * T balance ;

[0031] where, T BMS is the module temperature of the i-th battery module, T real_ij is the target sampling temperature at the j-th sampling point of the i-th battery module, T balance is the thermal equilibrium temperature of the i-th battery module, and ε is the weight coefficient.

[0032] In a possible implementation, after determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature, the method further includes:

[0033] Determining the absolute value of the difference between the target sampling temperature and the module temperature;

[0034] Judging the magnitude relationship between the absolute value of the difference and the preset buffer temperature difference;

[0035] If it is determined that the absolute value of the difference is greater than the preset buffer temperature difference, then use the target sampling temperature as the true temperature of the battery module;

[0036] If it is determined that the absolute value of the difference is less than or equal to the preset buffer temperature difference, then use the module temperature as the true temperature of the battery module.

[0037] In a second aspect, a device for obtaining the temperature of a battery module is provided, including:

[0038] A first acquisition module, configured to acquire the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature;

[0039] An outlier removal module, configured to perform outlier removal processing on the sampling point temperatures of each battery module according to the sampling point temperatures of the multiple sampling points of each battery module, to obtain the target sampling temperature of each battery module;

[0040] A second acquisition module, which acquires the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature;

[0041] A determination module, configured to determine the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

[0042] A device for obtaining the temperature of a battery module includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for obtaining the temperature of a battery module are implemented.

[0043] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for obtaining the temperature of a battery module are implemented.

[0044] In the solutions implemented by the above-mentioned method, device, computer device, and storage medium for obtaining the temperature of a battery module, outlier determination and removal can be performed on the temperature values sampled by abnormal temperature sensors, and the thermal equilibrium temperature of the battery module will be further obtained, taking into account the influence of ambient temperature and current. That is to say, the heat conduction situation between the internal temperature of the battery cell and the external temperature (i.e., the target sampling temperature) can be known. Finally, according to the thermal equilibrium temperature and the target sampling temperature, the module temperature of the battery module is determined, and an accurate and effective module temperature is obtained, so that when the functional modules of the subsequent battery management system implement relevant functional logics based on the module temperature, they can be more accurate. Description of the Drawings

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0046] Figure 1 is a schematic diagram of an application environment of the battery module temperature acquisition method in the present invention;

[0047] Figure 2 is a schematic flowchart of the battery module temperature acquisition method in an embodiment of the present invention;

[0048] Figure 3 is Figure 2 a schematic flowchart of step S20 in

[0049] Figure 4 is a schematic structural diagram of the battery module temperature acquisition device in an embodiment of the present invention;

[0050] Figure 5 is a schematic structural diagram of the battery module temperature acquisition device in an embodiment of the present invention. Specific Embodiments

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0052] The embodiments of the present invention provide a battery module temperature acquisition method, which can be applied in an application environment such as Figure 1 , including a battery module, a battery module temperature acquisition device, and a battery management system (BMS). Among them, temperature sampling points are provided on the battery module, and corresponding temperature sensors ( Figure 1 not shown in Figure 1 ) are arranged on the temperature sampling points to perform temperature sampling on the sampling points through the temperature sensors to obtain the temperature on the battery module. For example, in some application scenarios, the temperature sensor can be implemented using a thermistor NTC (Negative Temperature Coefficient). NTC uses the detected resistance value to obtain the resistance value of the corresponding sampling point temperature, and the corresponding sampling point temperature can be obtained by looking up the table using the resistance value. It should be noted that in other application scenarios, the temperature sensor can also be other sensors, detectors, etc. that can be used to detect the sampling point temperature. The specific embodiments of the present invention do not make limitations.

[0053] In an application scenario, the battery management system referred to in the present invention may refer to the battery management system in an automobile, or the battery management system in other fields or devices. The present invention does not make any limitations. For the convenience of understanding, in the present invention, the battery management system for a vehicle will be described. In the embodiments of the present invention, the battery module temperature acquisition device is used to acquire the sampling point temperature collected by the temperature sensor. According to the sampling point temperature, the battery module temperature acquisition method proposed by the present invention is used to estimate the accurate module temperature of the battery module, and the module temperature of the battery module is involved in the processing logic of each functional module of the battery management system. That is, each functional module of the battery management system can use the accurate module temperature of the battery module to execute the subsequent functional logic. For example, the above functional modules include but are not limited to functional modules such as battery fault handling, charging control, SOC calculation, and discharge power calculation.

[0054] It should be noted that Figure 1 The application environment schematic diagram shown here is only for illustrative purposes. In actual applications, the battery module temperature device can be an independent device applied to the battery management system, and the module temperature determined by using the battery module temperature acquisition method provided in the embodiments of the present invention is fed back to the battery management system; in some application scenarios, the battery module temperature device can be configured in each functional module of the battery management system, or each functional module of the battery management system can implement the battery module temperature acquisition method provided in the present embodiment to estimate the module temperature of the battery module, so that each functional module can execute the corresponding functional logic according to the module temperature. The present invention does not make specific limitations.

[0055] It can be understood that when using an NTC to sample the temperature of the sampling point, since the NTC is attached to the electrical chip surface of the battery module, in actual applications, it is very easy to have problems such as poor adhesion, water ingress, and resistance drift. As a result, the sampled temperature value of the NTC is likely to deviate from the true value. The method described in this article can perform outlier determination and rejection on abnormal NTC temperature values, and use the battery module temperature acquisition method proposed by the present invention to obtain an accurate and effective module temperature. Moreover, the temperature hysteresis caused by thermal equilibrium is considered, so that when the subsequent functional modules of the battery management system implement relevant functional logics based on the module temperature, they can be more accurate. For example, it can effectively avoid problems such as high-voltage power-off, sudden power increase, and sudden power decrease caused by NTC abnormalities. The embodiments of the present invention will be described in detail below with reference to specific embodiments.

[0056] In one embodiment, as Figure 2 shown, a battery module temperature acquisition method is provided. This method is applied toFigure 1 Taking the battery module temperature acquisition device in [ID] as an example, the steps are as follows:

[0057] S10: Obtain the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature.

[0058] It can be understood that a battery pack usually includes multiple battery modules. In the embodiments of the present invention, multiple temperature sampling points will be preset in each battery module. For example, two temperature sampling points can be set. It should be noted that in actual applications, according to requirements, other numbers of sampling points can be set on each battery module, and the present invention does not make limitations. For the convenience of describing the embodiments of the present invention, the embodiments of the present invention will be described by taking two sampling points as an example. As Figure 1 shown, the present invention can set two sampling points in each battery module, and the sampling point temperature is represented as T ij , where i in T ij represents the module number of the battery module in the battery pack, and j represents the temperature sampling point number of the battery module. Therefore, a battery module has two temperature sampling points, which are respectively represented by j = 0, 1.

[0059] Exemplarily, in the embodiments of the present invention, for each battery module, two NTCs can be respectively used to detect the sampling point temperatures of the two sampling points of each battery module. Therefore, during the operation of the vehicle, by using the NTC, the sampling point temperatures of each sampling point of each battery module under the current current and ambient temperature can be detected. Among them, the current current refers to the current of the battery module. It can be understood that under the current and ambient temperature, different temperatures will exist on the surface of the battery module. For the battery module temperature acquisition device, the sampling point temperatures of each battery module in all battery modules under the current current and ambient temperature can be obtained.

[0060] S20: According to the sampling point temperatures of multiple sampling points of each battery module, perform outlier rejection processing on the sampling point temperatures of each battery module to obtain the target sampling temperature of each battery module.

[0061] It should be noted that in actual applications, due to the self-defects of NTC detection, it is very likely that deviation values, that is, inaccurate or invalid temperature values, will occur in the detected sampling point temperatures. Therefore, it is also necessary to perform outlier rejection processing on the sampling point temperatures to obtain accurate and effective sampling point temperatures. In the embodiments of the present invention, the sampling point temperature after outlier rejection processing in the battery module is used as the target sampling temperature of the battery module.

[0062] Among them, in order to make the obtained target sampling temperature more valuable, a new outlier rejection method is proposed to obtain accurate and effective target sampling temperatures, which will be described in detail below.

[0063] That is, in S20, that is, based on the sampling point temperatures of multiple sampling points of each battery module, the sampling point temperatures of each battery module are subjected to outlier rejection processing to obtain the target sampling temperature of each battery module. As Figure 3 shown, the specific steps are as follows:

[0064] S21: Determine the average temperature of all the battery modules based on the sampling point temperatures of multiple sampling points of each battery module.

[0065] After obtaining the sampling point temperatures of multiple sampling points of each battery module, the sampling point temperatures of all battery modules in the battery pack are accumulated and divided by the total number of all sampling point temperatures, so as to obtain the average temperature corresponding to all battery modules in the battery pack. Let T avg represent the average temperature, then the calculation method of this T avg is where n represents the total number of sampling point temperatures of all battery modules.

[0066] S22: Determine the outlier temperature extreme value and the outlier temperature mean error corresponding to the battery module.

[0067] Among them, in one example, the outlier temperature extreme values in the embodiments of the present invention include high-temperature outlier extreme values and low-temperature outlier extreme values; correspondingly, the outlier temperature mean errors include high-temperature outlier mean errors and low-temperature outlier mean errors. The high-temperature outlier extreme values and low-temperature outlier extreme values are respectively obtained by simulating high and low temperature environments and calibrating the temperature test results. Taking the high-temperature outlier extreme value as an example, the embodiments of the present invention will pre-simulate a high-temperature environment so that the battery module is in this high-temperature environment for simulation test calibration to obtain the high-temperature outlier extreme value corresponding to the battery module. Correspondingly, the high-temperature outlier mean error can refer to the mean error of the high-temperature outlier temperature. Similarly, the low-temperature outlier extreme value and the low-temperature outlier mean error corresponding to the battery module can also be obtained.

[0068] S23: Determine whether there is an outlier temperature in the sampling point temperatures of multiple sampling points of each battery module according to the outlier temperature extreme value, the outlier temperature mean error, and the average temperature.

[0069] After obtaining the high-temperature outlier extreme value and the low-temperature outlier extreme value corresponding to the battery pack, as well as the high-temperature outlier mean error and the low-temperature outlier mean error according to the calibration results, it is possible to determine whether there is an outlier temperature in the sampling point temperatures of multiple sampling points of each battery module according to the outlier temperature extreme value, the outlier temperature mean error, and the average temperature.

[0070] In one embodiment, in step S231, that is, according to the outlier temperature extreme value, outlier temperature mean error, and average temperature, it is determined whether there is an outlier temperature among the sampling point temperatures of each battery module, which specifically includes the following steps:

[0071] S231: If it is determined that the sampling point temperature of the battery module is greater than or equal to the high-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is greater than or equal to the high-temperature outlier mean error, and the duration is longer than the preset duration, it is determined that the battery module has a high-temperature outlier temperature;

[0072] Step S231 corresponds to the process of determining whether there is a high-temperature outlier temperature in the battery module. For the sampling point temperature of each sampling point of the battery module, it is determined whether the sampling point temperature of this sampling point is greater than or equal to the high-temperature outlier extreme value, and whether the difference between the sampling point temperature and the average temperature is greater than or equal to the high-temperature outlier mean error, and whether the duration is longer than the preset duration.

[0073] Here, it is assumed that the sampling point temperature is T ij , the high-temperature outlier extreme value is T Herr , the average temperature is T avg , the high-temperature outlier mean error is T avg_σMax1 , and the preset duration is t stray , that is to say, if the sampling point temperature T ij ≥ high-temperature outlier extreme value T Herr , and (T ij - T avg ) ≥ high-temperature outlier mean error T avg_σMax1 , and the duration is the preset duration t stray or more, it means that the sampling point temperature T ij is a high-temperature outlier temperature, that is, the sampling point temperature of sampling point j of the battery module with module number i is a high-temperature outlier temperature, and the battery module with module number i has a high-temperature outlier temperature.

[0074] For easy understanding, here is another practical example for illustration. As mentioned above, a battery module has two sampling points. T ij represents the sampling point temperature corresponding to sampling point j with module number i in the table number module, and T i1-j represents the sampling point temperature corresponding to sampling point 1 - j of another sampling point in module number 1. Assuming that there are currently 16 modules in the battery pack, then there are 32 sampling point temperatures. Let the calibrated high-temperature outlier extreme value T Herr = 58 °C, and the calibrated high-temperature outlier mean error is T avg_σMax1= 15°C. If the sampling point temperature of the second sampling point of battery module 1 is 59°C, the sampling point temperature of the first sampling point of this battery module 1 is 45°C, and the average temperature corresponding to all battery modules is 44°C, then it can be seen that since 59°C ≥ T Herr = 58°C and 59°C - 44°C ≥ T avg_σMax1 = 15°C, and the duration exceeds the preset duration, then it is determined that the sampling point temperature of 59°C at the second sampling point of battery module 1 is a high-temperature outlier temperature.

[0075] S232: If it is determined that the sampling point temperature of the battery module is less than or equal to the low-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is greater than or equal to the low-temperature outlier mean error, and the duration is longer than the preset duration, then it is determined that the battery module has a low-temperature outlier temperature.

[0076] Step S231 corresponds to the process of determining whether there is a low-temperature outlier temperature in the battery module. For the sampling point temperature of each sampling point of the battery module, it is also determined whether the sampling point temperature is less than or equal to the low-temperature outlier extreme value, and whether the difference between the sampling point temperature and the average temperature is less than or equal to the low-temperature outlier mean error, and whether the duration is longer than the preset duration.

[0077] Similarly, here it is assumed that the sampling point temperature is T ij , the low-temperature outlier extreme value is T Lerr , the average temperature is T avg , the high-temperature outlier mean error is T avg_σMax2 , the preset duration is t stray , that is to say, if the sampling point temperature T ij ≤ the low-temperature outlier extreme value T Lerr , and (T ij - T avg ) ≤ the high-temperature outlier mean error T avg_σMax1 , and the duration is the preset duration t stray or more, then it means that the sampling point temperature is T ij is a low-temperature outlier temperature, that is, the sampling point temperature of the sampling point j of the battery module with module number i is a low-temperature outlier temperature, and the battery module with module number i has a low-temperature outlier temperature.

[0078] S24: If there is an outlier temperature, then the outlier temperature of each battery module is removed, and the target sampling temperature of each battery module is determined according to the non-outlier temperature of each battery module.

[0079] For example, if the sampling point temperature of the sampling point j of the battery module with module number i is a high-temperature outlier temperature, then the battery module with module number i has a high-temperature outlier temperature. At this time, it is considered that the sampling point temperature T ijis an invalid and inaccurate sampling point temperature, and the sampling point temperature T ij is removed; if the sampling point temperature of sampling point j of the battery module with module number i is a low-temperature outlier temperature, the battery module with module number i has a low-temperature outlier temperature. At this time, it is considered that the sampling point temperature T ij is an invalid and inaccurate sampling point temperature, and the sampling point temperature T ij is removed, and the target sampling temperature of each battery module is determined according to the non-outlier temperature of each battery module.

[0080] It should be noted that there are two situations worth explaining here. In the first situation, after the above removal, it is possible that the sampling point temperature of one of the sampling points of a certain battery module is removed, and the remaining sampling point temperature of the other sampling point is retained. Then, the remaining sampling point temperature of the other sampling point will be used to replace the removed sampling point temperature. In this way, the sampling point temperatures corresponding to the two sampling points are the same. That is, if T ij is determined to be a high-temperature outlier temperature, and T i1-j is not a high-temperature outlier temperature nor a low-temperature outlier temperature, then T ij will be replaced with T i1-j .

[0081] Take a practical example. Suppose there are 16 modules in the battery pack, then there are 32 sampling point temperatures. Let the calibrated high-temperature outlier extreme value T Herr = 58°C, and the calibrated high-temperature outlier mean error is T avg_σMax1 = 15°C. If the sampling point temperature of the second sampling point of battery module 1 is 59°C, and the sampling point temperature of the first sampling point of this battery module 1 is 45°C, and the average temperature corresponding to all battery modules is 44°C, then it can be seen that since 59°C ≥ T Herr = 58°C and 59°C - 44°C ≥ T avg_σMax1 = 15°C, and the duration exceeds the preset duration, then it is determined that the sampling point temperature of 59°C of the second sampling point of battery module 1 is a high-temperature outlier temperature. At this time, the sampling point temperature of 59°C of the second sampling point of battery module 1 is removed, and the sampling point temperature of 45°C of the first sampling point is used to replace 59°C. Finally, the sampling point temperatures of the two sampling points of battery module 1 are both 59°C, and this 59°C is the target sampling temperature of this battery module 1.

[0082] In the second situation, after the above removal, it is possible that the sampling point temperatures of both sampling points of a certain battery module are outlier temperatures, then the sampling point temperatures of both sampling points will be removed. For example, the sampling point temperatures T 11 and T 10All are excluded. In the embodiments of the present invention, the remaining non-excluded corresponding sampling point temperatures of adjacent battery modules can be used for substitution. It should be noted that in practical applications, the number of NTC failures that occur is generally less than the number of normal NTCs. Therefore, after the outlier exclusion and substitution in the embodiments of the present invention, the two sampling point temperatures of each battery module can obtain the same sampling point temperature, which is called the target sampling temperature of the battery module in the embodiments of the present invention.

[0083] It can be seen that in the above embodiment, the outlier temperatures are excluded and substituted, effectively obtaining the effective and correct sampling point temperature as the target sampling temperature of each battery module, effectively ensuring the correctness of subsequent results.

[0084] S25: If there is no outlier temperature, determine the target sampling temperature of each battery module according to the sampling point temperatures of multiple sampling points of each battery module.

[0085] In the embodiments of the present invention, if there is an outlier temperature, it means that the two sampling point temperatures measured by the battery module are close and relatively correct. At this time, directly determine the target sampling temperature of each battery module according to the sampling point temperatures of multiple sampling points of each battery module. As an example, the sampling point temperature of any one sampling point in the battery module can be used as the target sampling temperature of the battery module; or, the average value of the sampling point temperatures of the two sampling points of the battery module can be used as the target sampling temperature of the battery module.

[0086] Through steps S21 - S25, a new outlier substitution method is proposed, and the sampling point temperatures of all battery modules obtained are excluded and substituted, effectively ensuring the accuracy of the collected sampling point temperatures, effectively avoiding the abnormal sampling temperature caused by the abnormality of the NTC itself from participating in the subsequent processing logic, and avoiding problems such as high voltage and overcharge or over-discharge under battery abnormalities.

[0087] S30: Obtain the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature.

[0088] After steps S10 - S20, a relatively accurate target sampling temperature has been obtained. However, the sampling temperature only reflects the temperature on the surface of the battery cells in the battery module. The inventor has found that currently, most of the temperatures used in battery management systems directly adopt the temperature values sampled by NTC. In some application scenarios, such as when the battery current is large, especially during high - current charging, the temperature inside the battery cell is higher than the external temperature, and it takes a long time for the heat inside the battery cell to conduct to the NTC. In this way, this temperature conduction lag will cause the temperature sampled by the NTC during high - current charging to be on the low side, which will also lead to a deviation in the above - mentioned target sampling temperature. To solve this problem, after obtaining the target sampling temperature of the battery module in the embodiments of the present invention, it is also necessary to obtain the thermal equilibrium temperature of the battery module for subsequent processing to obtain the final true and more effective module temperature.

[0089] First, it is necessary to obtain the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature, where the current current and ambient temperature are the same current and ambient temperature as those at the time of collecting the sampling point temperature.

[0090] In one embodiment, in step S30, that is, in the process of obtaining the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature, it is necessary to pre - construct a thermal equilibrium equation corresponding to the battery module in the z - direction, and the z - direction corresponds to the height direction of the module battery cells.

[0091] Among them, the construction process and idea of the thermal equilibrium equation are as follows:

[0092] It can be understood that the battery module is usually a cuboid, including length, width, and height, and the length, width, and height correspond to the x - direction, y - direction, and z - direction respectively. Among them, the inventor has found through experiments that in the battery module of a vehicle, the temperature distribution in the x and y directions is relatively uniform, and there is mainly a temperature conduction error in the z - direction. Therefore, in the embodiments of the present invention, in order to reduce the calculation amount and simplify the model, it is assumed that the electrolyte medium in the battery cell is uniformly distributed along the Z - direction, and then the heat transfer model of the battery module can be obtained as:

[0093] Among them, C represents the specific heat capacity of the module battery cells, ρ represents the electrolyte density of the module battery cells, k is the thermal conductivity of the module battery cells; Q represents the heat generation of the battery cells in the battery module, and Q can be expressed as:

[0094]

[0095] Among them, V b represents the volume of the active material of the module battery cells, I represents the current of the battery module, T represents the real - time module temperature of the battery module, represents the heat generation rate of the chemical reaction of the module battery cells. It should be noted that this It can be obtained through experiments. For a determined module battery cell, this can be expressed as a function of SOC, that is: E represents the open-circuit voltage of the battery module, V represents the terminal voltage of the module battery. In addition, in the formula, I(E - V) = IR 2 , where R is the equivalent resistance of the module battery cell. This equivalent resistance can be obtained through cell parameter identification and is also a calibration parameter required for the functional logic of the battery management system SOC calculation module, etc., which will not be elaborated here.

[0096] Based on the above heat transfer model, the boundary conditions of the heat transfer model are:

[0097] Q f = A * ((T||z = 0) - T am ) * h;

[0098] (T|z = 0) = T real_ij ;

[0099] cell_height is the cell height of the battery module, s is the area of the module battery cell, Q is the heat generation of the cell of the battery module, h is the convective heat transfer coefficient between the module battery cell and the environment, A is the convective heat transfer coefficient inside the module battery cell, T am is the ambient temperature, T real_ij is the target sampling temperature of the jth sampling point of the ith battery module, T balance is the thermal equilibrium temperature.

[0100] Among them, according to the principle of thermal equilibrium, (T|z = 0) can be equivalently regarded as the sampling temperature, and the final thermal equilibrium equation can be expressed as: Through the above thermal equilibrium equation, the current current and the ambient temperature, the thermal equilibrium temperature corresponding to the battery module under the current current and the ambient temperature can be obtained.

[0101] It should be noted that after obtaining the above thermal equilibrium equation, through this thermal equilibrium equation, when the current of the battery module is I, the surface temperature and the core temperature of the battery cell after reaching thermal equilibrium, that is, the thermal equilibrium temperature T balance . In the embodiments of the present invention, through experiments, a two-dimensional map of the thermal equilibrium temperature T balance versus the current I and the ambient temperature T am will be established, so that the thermal equilibrium temperature T balance versus the current I and the ambient temperature T amThe corresponding relationship, that is, through this two-dimensional map, the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature can be found. It should be noted that in practical applications, the ambient temperature can be considered as the target sampling temperature of the initial battery module or can be measured separately. The specific method of the present invention is not limited.

[0102] S40: Determine the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

[0103] After the foregoing steps S10 - S30, the thermal equilibrium temperature and the target sampling temperature of the battery module can be obtained. It can be understood that although a relatively accurate target sampling temperature has been obtained, the sampling temperature only reflects the temperature on the surface of the battery cells of the battery module. However, the inventor found that most of the temperatures used in current battery management systems are directly the temperature values sampled by NTC. In some application scenarios, such as when the battery current is large, especially during large current charging, the temperature inside the battery cells is higher than the external temperature, and it takes a long time for the heat inside the battery cells to conduct to the NTC. In this way, this temperature conduction lag will cause the temperature sampled by the NTC to be too low during large current charging, which will also cause a deviation in the above-mentioned target sampling temperature. To solve this problem, the embodiment of the present invention will further obtain the thermal equilibrium temperature of the battery module, so as to know the heat conduction situation between the temperature inside the battery cells and the external temperature (i.e., the target sampling temperature), and finally determine the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

[0104] As an example, in step S40, the determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature means: determining the respective weights of the thermal equilibrium temperature and the target sampling temperature according to the current current and the ambient temperature, and finally determining the module temperature of the battery module according to the thermal equilibrium temperature, the target sampling temperature and their respective weights.

[0105] Specifically, the module temperature of the battery module is determined by the following formula:

[0106] T BMS = ε * T real_ij +(1 - ε) * T balance ;

[0107] Wherein, T BMS is the module temperature of battery module i, T real_ij is the target sampling temperature of the jth sampling point of battery module i, T balance is the thermal equilibrium temperature of battery module i, and ε is the weight coefficient. That is to say, in this embodiment, the weight corresponding to the target sampling temperature T real_ij is ε, Tbalance The corresponding weight is (1 - ε). It should be noted that the above weight coefficient ε can be obtained by looking up a table based on the current current and ambient temperature. The main considerations are heat generation and heat dissipation, and it is a calibrated value; the smaller the heat generation, the larger the coefficient ε, and the larger the heat generation, the smaller the coefficient ε.

[0108] In this embodiment, the final determined module temperature of the battery module is T BMS , this T BMS That is, the temperature used by each functional module of the battery management module. It can be seen that in the embodiment of the present invention, the temperature sampled by NTC is filtered and removed, and then considering the influence of current, ambient temperature, etc. on the heat conduction balance, and considering the influence of temperature error caused by heat conduction hysteresis, the finally calculated module temperature T BMS is more accurate and effective. This module temperature can be directly used in functional modules such as fault handling, charging control, SOC calculation, and discharge power calculation of the battery management system, so as to effectively avoid problems such as inaccurate module temperature caused by NTC anomalies, resulting in high-voltage power-off, sudden increase in power, and sudden decrease in power. In addition, it is worth noting that during the charging process of the natural cooling battery pack, the problem of too high battery pack temperature is likely to occur. Using the present invention can also predict the thermal equilibrium temperature in advance, and can also control the charging current in advance according to the predicted temperature to effectively avoid the safety risks caused by over-temperature of the battery pack.

[0109] In one embodiment, after step S40, that is, after determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature, the method further includes the following steps:

[0110] S50: Determine the absolute value of the difference between the target sampling temperature and the module temperature;

[0111] S60: Judge the magnitude relationship between the absolute value of the difference and the preset buffer temperature difference;

[0112] S70: If it is judged that the absolute value of the difference is greater than the preset buffer temperature difference, then use the target sampling temperature as the true temperature of the battery module;

[0113] S80: If it is judged that the absolute value of the difference is less than or equal to the preset buffer temperature difference, then use the module temperature as the true temperature of the battery module.

[0114] For steps S50 - S60, in the embodiment of the present invention, after obtaining the module temperature T BMS After that, in order to enhance the stability of functional modules such as charge and discharge control of the battery management system, a preset buffer temperature difference ΔT can be set again. This preset buffer temperature difference is also obtained through experimental calibration and will not be elaborated here. When the target sampling temperature Treal_ij When the difference between the operating temperature of the battery management system, that is, the module temperature T BMS is greater than ΔT, the final actual operating temperature of the battery management system adopts the target sampling temperature T real_ij , when the difference between the target sampling temperature T real_ij and the module temperature T BMS is less than or equal to ΔT, the final actual operating temperature of the battery management system adopts the module temperature T calculated as described above BMS , assuming that the final determined actual temperature of the battery module is T final , then this T final can be expressed as:

[0115] T final =(||T BMS -T real_ij ||-ΔT>0)*T real_ij +(||T BMS -T real_ij |-ΔT≤0)*T BMS .

[0116] In this embodiment, in order to enhance the stability of the charge and discharge control of the battery management system, the preset buffer temperature difference ΔT electricity obtained by calibration is used to coordinately determine the final actual temperature of the battery module as T final , further improving the stability of the functional modules of the battery management system.

[0117] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0118] In one embodiment, a battery module temperature acquisition device is provided, and this battery module temperature acquisition device corresponds one-to-one to the battery module temperature acquisition method in the above embodiment. As Figure 4 shown, this battery module temperature acquisition device includes a first acquisition module 101, a rejection module 102, a second acquisition module 103, and a determination module 104. The detailed descriptions of each functional module are as follows:

[0119] The first acquisition module 101 is used to acquire the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature;

[0120] The rejection module 102 is used to perform outlier rejection processing on the sampling point temperatures of each battery module according to the sampling point temperatures of the multiple sampling points of each battery module, and obtain the target sampling temperature of each battery module;

[0121] The second acquisition module 103 acquires the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature;

[0122] The determination module 104 is configured to determine the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

[0123] In one embodiment, the rejection module is specifically configured to:

[0124] Determine the average temperature of all the battery modules according to the sampling point temperatures of multiple sampling points of each battery module;

[0125] Determine the outlier temperature extreme value and the outlier temperature mean error corresponding to the battery pack;

[0126] Determine whether there is an outlier temperature in the sampling point temperatures of multiple sampling points of each battery module according to the outlier temperature extreme value, the outlier temperature mean error, and the average temperature;

[0127] If there is an outlier temperature, reject the outlier temperature of each battery module, and determine the target sampling temperature of each battery module according to the non-outlier temperatures of each battery module;

[0128] If there is no outlier temperature, determine the target sampling temperature of each battery module according to the sampling point temperatures of multiple sampling points of each battery module.

[0129] In one embodiment, the rejection module is further configured to:

[0130] If it is determined that the sampling point temperature of the battery module is greater than or equal to the high-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is greater than or equal to the high-temperature outlier mean error, and the duration is longer than the preset duration, it is determined that the battery module has a high-temperature outlier temperature;

[0131] If it is determined that the sampling point temperature of the battery module is less than or equal to the low-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is less than or equal to the low-temperature outlier mean error, and the duration is longer than the preset duration, it is determined that the battery module has a low-temperature outlier temperature.

[0132] In one embodiment, the second acquisition module is specifically configured to:

[0133] Pre-construct a thermal equilibrium equation corresponding to the battery module in the z direction, where the z direction corresponds to the height direction of the module battery cells;

[0134] Obtain the thermal equilibrium temperature corresponding to the battery module at the current current and ambient temperature through the thermal equilibrium equation;

[0135] The thermal equilibrium equation is:

[0136] Among them, Q f = A * ((T balance ||z = 0) - T am ) * h, (T balance ||z = 0) = T real_ij ;

[0137] cell_height is the cell height of the battery module, s is the area of the module cells, Q is the heat generation of the cells of the battery module, h is the convective heat transfer coefficient between the module cells and the environment, A is the convective heat transfer coefficient inside the module cells, T am is the ambient temperature, T real_ij is the target sampling temperature at the j-th sampling point of the i-th battery module, T balance is the thermal equilibrium temperature.

[0138] In one embodiment, the determining module is specifically configured to:

[0139] Determine the weights of the thermal equilibrium temperature and the target sampling temperature respectively according to the current current and the ambient temperature;

[0140] Determine the module temperature of the battery module according to the thermal equilibrium temperature, the target sampling temperature and their respective weights.

[0141] In one embodiment, the determining module is specifically configured to:

[0142] Determine the module temperature of the battery module through the following formula:

[0143] T BMS = ε * T real_ij + (1 - ε) * T balance ;

[0144] Among them, T BMS is the module temperature of the i-th battery module, T real_ij is the target sampling temperature at the j-th sampling point of the i-th battery module, T balance is the thermal equilibrium temperature of the i-th battery module, and ε is the weight coefficient.

[0145] In one embodiment, the determining module is further configured to:

[0146] Determine the absolute value of the difference between the target sampling temperature and the module temperature;

[0147] Judge the magnitude relationship between the absolute value of the difference and the preset buffer temperature difference;

[0148] If it is determined that the absolute value of the difference is greater than the preset buffer temperature difference, then use the target sampling temperature as the true temperature of the battery module;

[0149] If it is determined that the absolute value of the difference is less than or equal to the preset buffer temperature difference, then use the module temperature as the true temperature of the battery module.

[0150] For the specific limitations of the battery module temperature acquisition device, reference can be made to the limitations on the battery module temperature acquisition method in the above text, which will not be elaborated here. Each module in the above battery module temperature acquisition device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0151] In one embodiment, a battery module temperature acquisition device is provided, and its internal structure diagram can be as Figure 5 shown. The battery module temperature acquisition device can include a processor and a memory connected through a system bus. Among them, the processor of the battery module temperature acquisition device is used to provide computing and control capabilities. The memory of the battery module temperature acquisition device includes a non-volatile storage medium and a volatile storage medium. When the computer program is executed by the processor, it realizes a battery module temperature acquisition method.

[0152] In one embodiment, a battery module temperature acquisition device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following steps are realized:

[0153] Obtain the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature;

[0154] According to the sampling point temperatures of multiple sampling points of each battery module, perform outlier rejection processing on the sampling point temperatures of each battery module to obtain the target sampling temperature of each battery module;

[0155] Obtain the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature;

[0156] According to the thermal equilibrium temperature and the target sampling temperature, determine the module temperature of the battery module.

[0157] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, the following steps are realized:

[0158] Obtain the sampling point temperatures at multiple sampling points of each battery module among all battery modules under the current current and ambient temperature;

[0159] According to the sampling point temperatures at multiple sampling points of each battery module, perform outlier rejection processing on the sampling point temperatures of each battery module to obtain the target sampling temperature of each battery module;

[0160] Obtain the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature;

[0161] Determine the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature.

[0162] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments. Among them, any reference to a memory, storage, database or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0163] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0164] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for obtaining the temperature of a battery module, characterized in that, Including: Obtaining the sampling point temperatures of multiple sampling points of each battery module among all battery modules under the current current and ambient temperature; Performing outlier rejection processing on the sampling point temperatures of each battery module according to the sampling point temperatures of multiple sampling points of each battery module to obtain the target sampling temperature of each battery module; Obtaining the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature; Determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature; The performing outlier rejection processing on the sampling point temperatures of each battery module according to the sampling point temperatures of multiple sampling points of each battery module to obtain the target sampling temperature of each battery module includes: Determining the average temperature of all battery modules according to the sampling point temperatures of multiple sampling points of each battery module; Determining the outlier temperature extreme value and the outlier temperature mean error corresponding to the battery module; Determining whether there is an outlier temperature in the sampling point temperatures of multiple sampling points of each battery module according to the outlier temperature extreme value, the outlier temperature mean error and the average temperature; If there is an outlier temperature, rejecting the outlier temperature of each battery module, and determining the target sampling temperature of each battery module according to the non-outlier temperatures of each battery module; If there is no outlier temperature, determining the target sampling temperature of each battery module according to the sampling point temperatures of multiple sampling points of each battery module; The obtaining the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature includes: Pre-constructing a thermal equilibrium equation corresponding to the battery module in the z direction, where the z direction corresponds to the height direction of the module battery cells; Obtaining the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature through the thermal equilibrium equation; The heat balance equation is as follows: where Q f = A * ((T balance |z = 0) - T am ) * h, (T balance |z = 0) = T real_ij ; The cell_height is the height of the battery cells in the battery module, s is the area of the module cells, Q is the heat generation of the battery cells in the battery module, h is the convective heat transfer coefficient between the module cells and the environment, A is the convective heat transfer coefficient inside the module cells, T am is the ambient temperature, T real_ij is the target sampling temperature at the j-th sampling point of the i-th battery module, T balance is the thermal equilibrium temperature.

2. The method for obtaining the temperature of the battery module according to claim 1, wherein, The determining whether there is an outlier temperature in the sampling point temperatures of multiple sampling points of each battery module according to the outlier temperature extreme value, the outlier temperature mean error and the average temperature includes: If it is determined that the sampling point temperature of the battery module is greater than or equal to the high-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is greater than or equal to the high-temperature outlier mean error, and the duration is longer than the preset duration, it is determined that the battery module has a high-temperature outlier temperature; If it is determined that the sampling point temperature of the battery module is less than or equal to the low-temperature outlier extreme value, and the difference between the sampling point temperature and the average temperature is less than or equal to the low-temperature outlier mean error, and the duration is longer than the preset duration, it is determined that the battery module has a low-temperature outlier temperature.

3. The method for obtaining the temperature of the battery module according to any one of claims 1-2, characterized in that The determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature includes: Determining the respective weights of the thermal equilibrium temperature and the target sampling temperature according to the current current and ambient temperature; Determining the module temperature of the battery module according to the thermal equilibrium temperature, the target sampling temperature and their respective weights.

4. The method for obtaining the temperature of the battery module according to claim 3, wherein, The determining the module temperature of the battery module according to the thermal equilibrium temperature, the target sampling temperature and their respective weights includes: Determining the module temperature of the battery module through the following formula: T BMS = ε * T real_ij + (1 - ε) * T balance ; Among them, T BMS is the module temperature of battery module i, T real_ij is the target sampling temperature of the j-th sampling point of battery module i, T balance is the thermal equilibrium temperature of battery module i, and ε is the weight coefficient.

5. The method for obtaining the temperature of the battery module according to any one of claims 1-2, characterized in that, After determining the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature, the method further includes: Determining the absolute value of the difference between the target sampling temperature and the module temperature; Judging the magnitude relationship between the absolute value of the difference and a preset buffer temperature difference; If it is judged that the absolute value of the difference is greater than the preset buffer temperature difference, then using the target sampling temperature as the true temperature of the battery module; If it is judged that the absolute value of the difference is less than or equal to the preset buffer temperature difference, then using the module temperature as the true temperature of the battery module.

6. A battery module temperature acquisition device, characterized in that, Including: A first acquisition module, configured to acquire the sampling point temperatures of multiple sampling points of each battery module in all battery modules under the current current and ambient temperature; An outlier removal module, configured to perform outlier removal processing on the sampling point temperatures of each battery module according to the sampling point temperatures of the multiple sampling points of each battery module, so as to obtain the target sampling temperature of each battery module; A second acquisition module, acquiring the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature; A determination module, configured to determine the module temperature of the battery module according to the thermal equilibrium temperature and the target sampling temperature; The outlier removal module is further configured to: Determine the average temperature of all the battery modules according to the sampling point temperatures of the multiple sampling points of each battery module; Determine the outlier temperature extreme value and the outlier temperature mean error corresponding to the battery module; Determine whether there is an outlier temperature in the sampling point temperatures of multiple sampling points of each battery module according to the outlier temperature extreme value, the outlier temperature mean error and the average temperature; If there is an outlier temperature, then remove the outlier temperature of each battery module, and determine the target sampling temperature of each battery module according to the non-outlier temperature of each battery module; If there is no outlier temperature, then determine the target sampling temperature of each battery module according to the sampling point temperatures of multiple sampling points of each battery module; The second acquisition module is further configured to: Pre-construct a thermal equilibrium equation corresponding to the battery module in the z direction, where the z direction corresponds to the height direction of the module battery cells; Obtain the thermal equilibrium temperature corresponding to the battery module under the current current and ambient temperature through the thermal equilibrium equation; The heat balance equation is as follows: Among them, Q f = A * ((T balance |z = 0) - T am ) * h, (T balance |z = 0) = T real_ij ; The cell_height is the height of the battery cells in the battery module, s is the area of the module cells, Q is the heat generation of the battery cells in the battery module, h is the convective heat transfer coefficient between the module cells and the environment, A is the convective heat transfer coefficient inside the module cells, T am is the ambient temperature, T real_ij is the target sampling temperature at the j-th sampling point of the i-th battery module, T balance is the thermal equilibrium temperature.

7. A battery module temperature acquisition device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the battery module temperature acquisition method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the steps of the battery module temperature acquisition method according to any one of claims 1 to 5 are implemented.

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