A method for estimating dischargeable capacity of a power battery, a vehicle controller and a medium

Abstract

The application provides a power battery dischargeable quantity estimation method, a vehicle controller and a readable storage medium. The estimation method comprises the following steps: obtaining the current power battery state and historical travel energy consumption information of a target vehicle; obtaining an estimated heat generation according to the current power battery state, the historical travel energy consumption information and a target driving distance; obtaining a first predicted temperature rise of the power battery according to the estimated heat generation, cell attribute parameters and coolant attribute parameters; obtaining a target travel predicted temperature of the power battery according to the initial temperature of the power battery and the first predicted temperature rise; obtaining an estimated dischargeable correction coefficient according to the corresponding relationship between the target travel predicted temperature, the cell temperature and the dischargeable correction coefficient; and obtaining an estimated dischargeable capacity according to the estimated dischargeable correction coefficient. The application can improve the accuracy of the dischargeable quantity in the full temperature range and realize accurate estimation of the remaining driving distance and the remaining power at any temperature.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle battery management technology, and in particular to a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium. Background Technology

[0002] The discharge capacity of a power battery (hereinafter referred to as battery) is an important indicator for measuring battery performance. It is the capacity that the battery can release after being fully charged under certain conditions, and is generally measured in ampere-hours (AH). For power batteries, the discharge capacity is constrained by a variety of factors, which can be broadly categorized as follows:

[0003] 1. Discharge rate: The discharge capacity of a battery gradually decreases as the discharge rate increases. This is mainly due to the influence of the battery's internal resistance. Increased current leads to severe voltage polarization, causing the battery to reach the discharge cutoff voltage earlier and end the discharge process.

[0004] 2. Battery cell temperature: When the electrolyte temperature decreases, the activity of the internal electrodes decreases, and the electrolyte viscosity increases. Taking ternary lithium-ion batteries as an example, the ability of lithium to insert and extract decreases, ion movement is subject to greater resistance, the internal resistance of the battery increases, the polarization voltage becomes severe, and the battery is more likely to reach the discharge cutoff voltage.

[0005] 3. Cut-off voltage: The level of the cut-off voltage affects the discharge capacity, but it also affects the cycle life of the battery. Therefore, the cut-off voltage is specified before the battery leaves the factory, and the cut-off voltage of the electric vehicle remains unchanged throughout its life cycle.

[0006] When electric vehicles are in use, the impact of temperature rise on the battery's discharge capacity is not taken into account, resulting in an underestimation of the discharge capacity and poor accuracy in the early stages of use. This leads to a shorter estimated driving range and may ultimately cause unnecessary range anxiety for users, resulting in a poor user experience.

[0007] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to address the technical problems of low discharge capacity and poor accuracy in the early-stage calculation of electric vehicle usage in the prior art. This invention provides a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium. This invention can improve the accuracy of the discharge capacity across the entire temperature range, laying a good foundation for obtaining accurate driving range at any temperature, thereby improving vehicle usage efficiency and reducing user anxiety.

[0009] To achieve the above objectives, the present invention provides a method for estimating the discharge capacity of a power battery, comprising the following steps:

[0010] Obtain the current power battery status and historical travel energy consumption information of the target vehicle; the current power battery status includes the initial temperature of the power battery;

[0011] Based on the current power battery status, the historical travel energy consumption information, and the target driving mileage, the estimated heat generation is obtained;

[0012] Based on the estimated heat generation, the cell attribute parameters of the power battery, and the coolant attribute parameters, the first predicted temperature rise of the power battery is obtained.

[0013] Based on the initial temperature and the first predicted temperature rise, the target range predicted temperature of the power battery is obtained.

[0014] Based on the predicted temperature of the target travel distance and the correspondence between the cell temperature of the power battery and the discharge correction coefficient, the estimated discharge correction coefficient is obtained; and based on the estimated discharge correction coefficient, the estimated discharge capacity of the power battery is obtained.

[0015] Optionally, the historical mileage energy consumption information includes the historical mileage information of the target vehicle; before obtaining the estimated heat generation based on the current power battery status, the historical mileage energy consumption information, and the target mileage, the estimation method further includes:

[0016] The target mileage is obtained based on the historical travel information; or the navigation information of the target vehicle is obtained, and the navigation mileage of the navigation information is used as the target mileage.

[0017] Optionally, the current power battery status also includes the current cell voltage of the power battery; the historical travel energy consumption information also includes the average driving speed and average energy consumption of the target vehicle;

[0018] The step of obtaining the estimated heat generation based on the current power battery status, the historical travel energy consumption information, and the target driving mileage includes:

[0019] The estimated heat generation is obtained based on the current cell voltage, the target driving range, the average driving speed, and the average energy consumption.

[0020] Optionally, obtaining the estimated heat generation based on the current cell voltage, the target driving range, the average driving speed, and the average energy consumption includes:

[0021] The estimated travel time is obtained based on the target mileage and the average speed.

[0022] The estimated average current is obtained based on the current cell voltage, the estimated driving time, and the average energy consumption.

[0023] The estimated heat generation is obtained based on the estimated average current, the internal resistance of each cell, the number of cells in the power battery, and the estimated driving time.

[0024] Optionally, the cell attribute parameters of the power battery include the total mass of all the cells of the power battery and the specific heat capacity of the cells; the coolant attribute parameters include the mass of the coolant of the power battery and the specific heat capacity of the coolant; obtaining the first predicted temperature rise of the power battery based on the estimated heat generation, the cell attribute parameters of the power battery, and the coolant attribute parameters includes:

[0025] The first predicted temperature rise of the power battery is obtained based on the estimated heat generation, the total mass of all the battery cells, the specific heat capacity of the battery cells, the mass of the coolant, and the specific heat capacity of the coolant.

[0026] Optionally, before obtaining the target range prediction temperature of the power battery based on the initial temperature and the first predicted temperature rise, the estimation method further includes:

[0027] Obtain the ambient temperature; and based on the convective heat transfer coefficient, the surface area of ​​the power battery pack, the initial temperature, and the ambient temperature, obtain the amount of heat loss dissipated into the environment.

[0028] Calculate the difference between the estimated heat generation and the heat loss, and based on the difference, the cell attribute parameters of the power battery, and the coolant attribute parameters, obtain the second predicted temperature rise of the power battery;

[0029] The step of obtaining the target range prediction temperature of the power battery based on the initial temperature and the first predicted temperature rise includes:

[0030] The target range prediction temperature of the power battery is obtained based on the initial temperature and the second predicted temperature rise.

[0031] Optionally, the prediction method further includes:

[0032] The historical trip energy consumption information is updated according to a preset estimation cycle, and the starting temperature is updated using the real-time temperature during the target vehicle's driving process.

[0033] And according to the preset estimation period, all steps of the power battery discharge capacity estimation method are repeated during the driving process at the target driving mileage.

[0034] To achieve the above objectives, the present invention also provides a vehicle controller, which includes a discharge capacity estimation device or includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the power battery discharge capacity estimation method as described in any of the above claims.

[0035] The discharge capacity estimation device includes: a estimation parameter acquisition module, a heat generation estimation module, a temperature rise prediction module, a prediction temperature acquisition module, and a discharge capacity estimation module.

[0036] The estimated parameter acquisition module is configured to acquire the current power battery status and historical travel energy consumption information of the target vehicle; the current power battery status includes the initial temperature of the power battery;

[0037] The heat generation estimation module is configured to obtain the estimated heat generation based on the current power battery status, the historical travel energy consumption information, and the target driving mileage.

[0038] The temperature rise prediction module is configured to obtain the first predicted temperature rise of the power battery based on the estimated heat generation, the cell attribute parameters of the power battery, and the coolant attribute parameters.

[0039] The predicted temperature acquisition module is configured to obtain the target travel predicted temperature of the power battery based on the initial temperature and the first predicted temperature rise.

[0040] The discharge capacity estimation module is configured to obtain an estimated discharge correction coefficient based on the predicted temperature of the target travel and the correspondence between the cell temperature of the power battery and the discharge correction coefficient; and to obtain the estimated discharge capacity of the power battery based on the estimated discharge correction coefficient.

[0041] Optionally, the discharge capacity estimation device further includes a driving range estimation module and / or a remaining power estimation module;

[0042] The driving range estimation module is configured to obtain the estimated driving range based on the estimated discharge capacity of the power battery and the estimated average driving speed of the target vehicle.

[0043] The remaining power estimation module is configured to obtain the estimated remaining power of the power battery based on the estimated discharge capacity and the theoretical discharge capacity.

[0044] To achieve the above objectives, the present invention also provides a readable storage medium storing a computer program, which, when executed by a processor, implements the power battery discharge capacity estimation method described in any of the above claims.

[0045] Compared with the prior art, the present invention provides a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium, which have the following advantages:

[0046] The present invention provides a method for estimating the discharge capacity of a power battery. First, based on the current state of the power battery of the target vehicle, historical energy consumption information (i.e., the user's driving habits), and Joule's law, the estimated heat generation of the power battery is calculated. Then, based on the estimated heat generation and relevant battery attribute parameters, the temperature rise generated by the power battery itself during vehicle operation (i.e., the first predicted temperature rise) is estimated. Next, based on the initial temperature of the power battery and the first predicted temperature rise, the target range predicted temperature of the power battery is obtained. Finally, based on the estimated battery temperature (i.e., the target range predicted temperature), a discharge capacity correction coefficient is obtained, thereby obtaining an accurate discharge capacity throughout the entire vehicle's usage. This invention improves the accuracy of the discharge capacity across the entire temperature range, laying a solid foundation for achieving accurate driving range at any temperature. This not only benefits the high performance, high efficiency, and operational safety of the battery pack but also improves vehicle utilization efficiency and reduces user anxiety.

[0047] Since the vehicle controller and readable storage medium provided by this invention belong to the same inventive concept as the power battery discharge capacity estimation method provided by this invention, the vehicle controller and readable storage medium provided by this invention have at least all the advantages of the power battery discharge capacity estimation method provided by this invention. For details on the beneficial effects of the vehicle controller and readable storage medium provided by this invention, please refer to the above description of the beneficial effects of the power battery discharge capacity estimation method provided by this invention, which will not be repeated here. Attached Figure Description

[0048] Figure 1 This is a schematic diagram comparing the theoretical discharge capacity and actual discharge capacity of the power battery of a certain electric vehicle in related technologies.

[0049] Figure 2 This is a schematic diagram of the overall process of the power battery discharge capacity estimation method provided in the first embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the data processing flow for a specific example of the power battery discharge capacity estimation method provided by the present invention.

[0051] Figure 4This is a schematic diagram comparing the changes in discharge capacity before and after using the power battery discharge capacity estimation method provided by the present invention, as well as during the actual discharge process.

[0052] Figure 5 A block diagram of a vehicle controller discharge quantity prediction device provided in a second embodiment of the present invention;

[0053] Figure 6 A block diagram illustrating the structure of a vehicle controller provided in a third embodiment of the present invention;

[0054] The reference numerals in the attached figures are as follows:

[0055] Predicted parameter acquisition module-110, heat generation prediction module-120, temperature rise prediction module-130, predicted temperature acquisition module-140, dischargeable capacity prediction module-150, driving range prediction module-160, remaining power prediction module-170.

[0056] Processor-210, memory-220, communication interface-230, communication bus-240. Detailed Implementation

[0057] The following detailed description, in conjunction with the accompanying drawings, provides a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clarify the illustration of the embodiments of the present invention. Please refer to the drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of the present invention. Any modifications to the structure, changes in proportions, or adjustments to the size, provided that the effects and objectives achieved by the present invention are the same or similar, should still fall within the scope of the technical content disclosed in the present invention. Specific design features of the present invention disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes, will be determined in part by the specific application and usage environment. Furthermore, in the embodiments described below, the same reference numerals are sometimes used across different drawings to denote the same parts or parts having the same function, omitting repeated descriptions. In this specification, similar reference numerals and letters are used to denote similar items; therefore, once an item is defined in one figure, it need not be discussed further in subsequent figures. Furthermore, if the methods described herein involve a series of steps, and the order of these steps presented herein is not necessarily the only possible order in which they can be performed, some of the described steps may be omitted and / or other steps not described herein may be added to the method.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The singular forms “a,” “an,” and “the” include plural objects. The term “or” is generally used to mean “and / or,” the term “several” is generally used to mean “at least one,” and the term “at least two” is generally used to mean “two or more.” Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0059] To facilitate a better understanding of the present invention, before detailing the specific implementation methods of the power battery discharge capacity estimation method, vehicle controller, and readable storage medium provided by the present invention, the research process of the present invention is briefly described as follows:

[0060] To address the technical problems of low accuracy and inaccurate calculations of the discharge capacity in the early stages of electric vehicle use in existing technologies, the inventors of this application, through extensive research and continuous practical application, discovered that although the actual usage scenarios of electric vehicles are complex, with temperatures ranging from -40℃ to +60℃ and discharge currents varying from 0A to several hundredA, and the usable capacity of the electric vehicle battery varies under such complex usage scenarios, the discharge capacity of the electric vehicle's power battery is closely related to the temperature of the battery pack. For example, please refer to Table 1 below, which shows the correspondence between the discharge capacity and the discharge correction factor for a certain model of power battery at different temperatures:

[0061] Temperature / °C -30 -20 -10 0 10 20 25 30 40 Dischargeable capacity / AH 62 77 85 92 96 99 100 100.1 100.2 Correction factor / 0.62 0.77 0.85 0.92 0.96 0.99 1 1.001 1.002

[0062] In related technologies, BMS systems generally use the capacity at 25 degrees Celsius as the standard capacity. The BMS system acquires the battery pack temperature in real time, and the discharge capacity at different temperatures is obtained using the correction coefficients in Table 1. It is particularly important to note that, as those skilled in the art will understand, the power battery is one of the "three electric systems" of new energy vehicles, directly determining the vehicle's driving range; a cell refers to the individual battery cell and its casing technology; a power battery typically includes one or more cells; and the battery pack is one of the core components of a power battery. Cells form modules, and modules form a battery pack. Specifically, in this article, unless otherwise specified, the temperature of the power battery, the temperature of the battery pack, and the temperature of the cell all refer to the same thing: the temperature of the cell.

[0063] Further research revealed that during the use of electric vehicles, the discharge capacity of the power battery gradually increases with the rise in battery pack temperature. However, the BMS system in related technologies only considers the impact of temperature on the discharge capacity of the power battery during the start-up phase of the electric vehicle, failing to account for the impact of temperature changes on the discharge capacity as the journey progresses. This results in an underestimation of the discharge capacity calculated in the early stages of use, leading to a shorter driving range. For an example, please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram comparing the theoretical discharge capacity (i.e., the temperature does not change during the discharge process) and the actual discharge capacity of a power battery for a certain electric vehicle in related technologies. Figure 1 As shown by the blue line, at -20 degrees Celsius, the theoretical discharge capacity is 77%, and the discharge capacity calculated by the BMS system is also 77AH (77%). However, during actual electric vehicle discharge, the battery temperature rises, resulting in an increase in the discharge capacity. The actual discharge capacity curve is shown in red. The difference between the red and blue lines represents the estimation error of the discharge capacity introduced by the BMS system. Therefore, the greater the temperature rise of the battery pack, the greater this calculation error becomes, leading to a larger error in the BMS system's calculation of the remaining usable capacity (SOCT, SOCT = discharge capacity at current temperature / discharge capacity at room temperature).

[0064] Based on the above research, the core idea of ​​this invention is to provide a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium. This invention can improve the accuracy of the discharge capacity across the entire temperature range, laying a good foundation for achieving accurate driving range at any temperature, thereby improving vehicle utilization efficiency and reducing user anxiety.

[0065] It should be noted that the power battery discharge capacity estimation method and readable storage medium provided by this invention can be applied to the vehicle controller provided by this invention, and the power battery discharge capacity estimation method, vehicle controller, and readable storage medium provided by this invention can be applied to electric vehicles. It should be understood that the terms "automobile" or "of an automobile" or other similar terms as used herein include general motor vehicles, such as passenger vehicles including SUVs, buses, trucks, and various commercial vehicles, and include hybrid vehicles, electric vehicles, and plug-in hybrid electric vehicles.

[0066] To achieve the above-mentioned goals, a first embodiment of the present invention provides a method for estimating the discharge capacity of a power battery. Specifically, please refer to... Figure 2 , Figure 2 This is a schematic diagram of the overall process for estimating the discharge capacity of a power battery according to the first embodiment of the present invention. Figure 2 As can be seen, the method for estimating the discharge capacity of a power battery provided in this embodiment includes the following steps:

[0067] S100: Obtain the current power battery status and historical travel energy consumption information of the target vehicle; the current power battery status includes the initial temperature of the power battery;

[0068] S200: Based on the current power battery status, the historical travel energy consumption information, and the target driving mileage, the estimated heat generation is obtained;

[0069] S300: Based on the estimated heat generation, the cell attribute parameters of the power battery, and the coolant attribute parameters, the first predicted temperature rise of the power battery is obtained;

[0070] S400: Based on the initial temperature and the first predicted temperature rise, the target range prediction temperature of the power battery is obtained;

[0071] S500: Based on the predicted temperature of the target travel distance and the correspondence between the cell temperature of the power battery and the discharge correction coefficient, an estimated discharge correction coefficient is obtained; and based on the estimated discharge correction coefficient, the estimated discharge capacity of the power battery is obtained.

[0072] Therefore, the power battery discharge capacity estimation method provided by this invention first calculates the estimated heat generation of the power battery based on the current power battery state of the target vehicle, historical travel energy consumption information (i.e., the user's driving habits), and Joule's law. Then, based on the estimated heat generation and relevant battery attribute parameters, the temperature rise generated by the power battery itself during vehicle operation (i.e., the first predicted temperature rise) is estimated. Next, based on the initial temperature of the power battery and the first predicted temperature rise, the target travel predicted temperature of the power battery is obtained. Finally, based on the estimated battery temperature (i.e., the target travel predicted temperature), a discharge capacity correction coefficient is obtained, thus obtaining an accurate discharge capacity throughout the entire vehicle's usage. This invention improves the accuracy of discharge capacity across the entire temperature range, laying a solid foundation for achieving accurate driving range at any temperature. It not only benefits the high performance, high efficiency, and operational safety of the battery pack but also improves vehicle utilization efficiency and reduces user anxiety.

[0073] It should be noted that, as those skilled in the art will understand, the present invention does not impose excessive limitations on the specific type of power battery. For example, the power battery may be, but is not limited to, lead-acid batteries, nickel-cadmium batteries, and lithium-ion batteries.

[0074] Preferably, in some exemplary embodiments, before step S200 obtains the estimated heat generation based on the current power battery state, the historical travel energy consumption information, and the target driving mileage, the estimation method further includes:

[0075] S101: Obtain the navigation information of the target vehicle and use the navigation mileage of the navigation information as the target driving mileage. Therefore, the power battery discharge capacity estimation method provided by the present invention obtains the target driving mileage based on the navigation information of the target vehicle, thus the obtained target driving mileage is relatively accurate, thereby further improving the accuracy of power battery discharge capacity estimation. It should be noted that, as those skilled in the art will understand, the present invention does not impose excessive limitations on the specific method of obtaining the navigation information. For example, in some embodiments, the navigation information can be calculated based on the departure and destination of the target vehicle when the vehicle starts; in other embodiments, the navigation information can also be obtained from the cloud.

[0076] Preferably, in some exemplary embodiments, the historical mileage energy consumption information includes the historical mileage information of the target vehicle; before step S200 obtains the estimated heat generation based on the current power battery state, the historical mileage energy consumption information, and the target mileage, the estimation method includes:

[0077] S001: Based on the historical travel information, the target mileage is obtained.

[0078] Therefore, the power battery discharge capacity estimation method provided by this invention obtains the target mileage information based on the target vehicle's historical travel information. This method is applicable even without navigation information, enabling the prediction of the power battery's discharge capacity, thereby improving the robustness and applicability of the power battery discharge capacity estimation method provided by this invention. For specific target vehicles, whether private cars or commercial vehicles, user habits are generally fixed. Taking private cars as an example, their uses are mainly concentrated on commuting to and from get off work, picking up and dropping off children at school, etc. The start time and distance for these activities are usually fixed, and navigation information is typically unavailable.

[0079] For a specific target vehicle, based on its historical travel information, it travels from point A to point B around 7:00 AM on weekdays and from point B to point A around 5:00 PM on weekdays. If, on Tuesday morning around 7:10 AM, the vehicle is found to have started from point A without navigation information, then based on the target vehicle's historical travel information, the distance traveled from point A to point B can be used as the target driving mileage.

[0080] Therefore, as those skilled in the art will understand, as a preferred method, obtaining the target mileage based on the navigation information of the target vehicle results in a more accurate estimate of the discharge capacity, especially suitable for driving scenarios with navigation information; while obtaining the target mileage based on historical trip information has better applicability and user-friendliness, such as being particularly suitable for commuting conditions.

[0081] It should be noted that, as those skilled in the art will understand, the above-described methods for obtaining the target mileage are merely illustrative and not limitations of the present invention. Other methods besides those described above can also be used to determine the target mileage, but due to space limitations, they will not be listed here.

[0082] Preferably, in some exemplary embodiments, the current state of the power battery also includes the current cell voltage of the power battery; the historical travel energy consumption information also includes the average driving speed and average energy consumption of the target vehicle;

[0083] Correspondingly, step S200 obtains the estimated heat generation based on the current power battery status, the historical travel energy consumption information, and the target driving mileage, specifically including: obtaining the estimated heat generation based on the current cell voltage, the target driving mileage, the average driving speed, and the average energy consumption.

[0084] Therefore, the power battery discharge capacity estimation method provided by the present invention estimates the heat generation based on the current cell voltage, the target driving range, the average driving speed, and the average energy consumption using Joule's law, laying a solid foundation for further improving the accuracy of discharge capacity estimation.

[0085] Further, obtaining the estimated heat generation based on the current cell voltage, the target driving range, the average driving speed, and the average energy consumption includes:

[0086] S210: Based on the target driving distance and the average driving speed, the estimated driving time is obtained;

[0087] S220: Based on the current cell voltage, the estimated driving time, and the average energy consumption, the estimated average current is obtained;

[0088] S230: Based on the estimated average current, the internal resistance of each of the cells, the number of cells in the power battery, and the estimated driving time, the estimated heat generation is obtained.

[0089] Therefore, the power battery discharge capacity estimation method provided by the present invention first obtains the estimated driving time based on the target driving mileage and average driving speed, then obtains the estimated average current based on the current cell voltage, the estimated driving time, and the average energy consumption, and finally obtains the estimated heat generation based on the estimated average current, the relevant heat generation attribute information of the power battery (such as the internal resistance of each cell and the number of cells in the power battery) and the estimated driving time using Joule's law. The logic is clear and simple, and it is easy to implement.

[0090] It should be noted that those skilled in the art should understand that the current cell voltage can be obtained by measurement; the method for obtaining the target driving mileage has been described in detail above and will not be repeated here; the average driving speed can be obtained from all historical driving information and the corresponding historical driving time in the historical driving energy consumption information; the average energy consumption can be obtained from the total historical driving mileage and total power consumption.

[0091] Exemplary, in some exemplary embodiments, step S210 can calculate the estimated travel time using the following formula (1):

[0092] (1)

[0093] In the above formula (1), The estimated travel time, The target driving mileage, The average driving speed is denoted as .

[0094] For example, as mentioned above, if the navigation mileage of the navigation information is used as the target driving mileage, then the target driving mileage For the navigation mileage If the target mileage is obtained based on the historical travel information, then the target mileage... Mileage of the selected historical trip information .

[0095] It should be noted that those skilled in the art should understand that the above-described methods for obtaining estimated driving time are merely exemplary descriptions and not limitations of the present invention. The present invention does not impose excessive limitations on the methods for obtaining estimated driving time. For example, in embodiments with navigation information, the estimated driving time can also be obtained based on the navigation driving time of the target vehicle's navigation information. This configuration lays a solid foundation for further improving the accuracy of the estimated discharge capacity. Furthermore, in embodiments without navigation information, the estimated driving time can also be the travel time corresponding to the historical travel information corresponding to the target mileage. Of course, other methods besides those described above are also possible, and will not be listed here.

[0096] Furthermore, in some exemplary embodiments, step S220 can calculate the estimated average current using the following formula (2):

[0097] (2)

[0098] In the above formula (2), For the estimated average current, The average energy consumption is... The estimated travel time, The current cell voltage.

[0099] Furthermore, in some exemplary embodiments, step S230 can calculate the estimated heat production using the following formula (3):

[0100] (3)

[0101] In the above formula (3), For the estimated heat production, For the estimated average current, Let be the internal resistance of each cell in the power battery. The estimated travel time, N represents the number of cells in the battery pack of the power battery, where N is an integer greater than or equal to 1.

[0102] Specifically, the internal resistance of the battery cell can be obtained based on the HPCC (Hybrid Pulse Power Characteristic, a characteristic used to reflect the pulse charge and discharge performance of a power battery) parameters. For more detailed information on how to obtain the internal resistance of the battery cell based on its HPCC parameters, please refer to relevant technologies known to those skilled in the art; this will not be elaborated upon here.

[0103] It should be noted that, as those skilled in the art will understand, the method for obtaining the estimated heat generation in steps S210-S230 is merely an exemplary description of a preferred embodiment and not a limitation of the present invention. The present invention does not impose excessive limitations on the specific implementation of step S200 based on the current power battery state, the historical energy consumption information, and the target driving mileage. For example, in some other embodiments, a battery pack heat generation estimation model can be pre-constructed, the input of which is the current power battery state (e.g., the current cell voltage), the historical energy consumption information, and the target driving mileage, and the output is the estimated heat generation. Furthermore, the present invention does not impose excessive limitations on the construction method of the battery pack heat generation estimation model; it can be, but is not limited to, being constructed through data fitting and neural network model recognition.

[0104] Preferably, in some exemplary embodiments, the cell attribute parameters of the power battery include the total mass of all the cells of the power battery and the specific heat capacity of the cells; the coolant attribute parameters include the mass of the coolant of the power battery and the specific heat capacity of the coolant. Step S300, based on the estimated heat generation and the cell attribute parameters and coolant attribute parameters of the power battery, obtains the first predicted temperature rise of the power battery, specifically including:

[0105] The first predicted temperature rise of the power battery is obtained based on the estimated heat generation, the total mass of all the battery cells, the specific heat capacity of the battery cells, the mass of the coolant, and the specific heat capacity of the coolant.

[0106] With this configuration, the power battery discharge capacity estimation method provided by the present invention obtains the temperature rise of the power battery based on the estimated heat generation, the total mass of all the battery cells, the specific heat capacity of the battery cells, the mass of the coolant, and the specific heat capacity of the coolant. The estimated heat generation is obtained using Joule's law, and the total mass of the battery cells, the specific heat capacity of the battery cells, the mass of the coolant, and the specific heat capacity of the coolant are properties of the power battery itself. Therefore, it can lay a solid foundation for further improving the accuracy of discharge capacity estimation.

[0107] Exemplary, in some exemplary embodiments, step 300 can calculate the first predicted temperature rise of the power battery using the following formula (4):

[0108] (4)

[0109] In the above formula (4), For the first predicted temperature rise, For the estimated heat production, The specific heat capacity of the battery cell is... The total mass of all the said cells, The specific heat capacity of the coolant. The mass of the coolant.

[0110] Preferably, in some exemplary embodiments, before obtaining the target range prediction temperature of the power battery in step S400 based on the initial temperature and the first predicted temperature rise, the estimation method further includes:

[0111] S310: Obtain the ambient temperature; and based on the convective heat transfer coefficient, the surface area of ​​the power battery pack, the initial temperature, and the ambient temperature, obtain the amount of heat loss dissipated into the environment.

[0112] S320: Calculate the difference between the estimated heat generation and the heat loss (i.e., the estimated heat rise), and obtain the second predicted temperature rise of the power battery based on the difference, the cell attribute parameters of the power battery, and the coolant attribute parameters.

[0113] Correspondingly, step S400, which involves obtaining the target range prediction temperature of the power battery based on the initial temperature and the first predicted temperature rise, specifically includes: obtaining the target range prediction temperature of the power battery based on the initial temperature and the second predicted temperature rise.

[0114] Therefore, the power battery discharge capacity estimation method provided by the present invention obtains the heat loss based on the convective heat transfer coefficient, the battery pack surface area, the initial temperature, and the ambient temperature. Then, it obtains the actual estimated heat rise based on the difference between the estimated heat generation and the heat loss. This can further improve the accuracy of the estimated heat rise, thereby laying the foundation for more accurate temperature rise prediction based on the estimated heat rise, the cell attribute parameters of the power battery, and the coolant attribute parameters. This leads to more accurate target range prediction temperature and discharge capacity, ensuring that electric vehicles can achieve a more accurate driving range and estimated remaining charge (SOCT) from the initial use stage to the final stage of the target driving range.

[0115] For example, in some exemplary embodiments, the amount of heat loss dissipated into the environment can be calculated in step S310 by the following formula (5):

[0116] (5)

[0117] In equation (5), This refers to the amount of heat loss emitted into the environment. Convection heat transfer coefficient (unit: ), This refers to the surface area of ​​the battery pack of the power battery. The starting temperature is... For the first predicted temperature rise, The ambient temperature The estimated travel time is given.

[0118] Furthermore, in some exemplary embodiments, the second predicted temperature rise of the power battery in step S320 can be calculated using the following formula (6):

[0119] (6)

[0120] In the above formula (6), For the second predicted temperature rise, For the estimated heat production, This refers to the amount of heat loss emitted into the environment. The specific heat capacity of the battery cell is... The total mass of all the said cells, The specific heat capacity of the coolant. The mass of the coolant.

[0121] Correspondingly, in step S400, the target travel prediction temperature of the power battery is obtained by the following formula (7):

[0122] (7)

[0123] In the above formula (7), Predict the temperature for the target travel distance. The starting temperature is... This is the second predicted temperature rise.

[0124] For example, in a specific example, if the predicted target travel temperature is 40°C, please refer to Table 1 and, in conjunction with step S500, based on the correspondence between the predicted target travel temperature and the cell temperature of the power battery and the discharge correction coefficient, it can be seen that the corresponding estimated discharge correction coefficient is 1.002. Assuming that the BMS system generally uses the capacity at 25°C as the standard capacity of 100, and referring to Table 1, using the power battery discharge capacity estimation method provided by this invention, the corrected discharge capacity is 100.2.

[0125] Preferably, in some exemplary embodiments, please continue to refer to Figure 2 ,from Figure 2 It can be seen that the method for estimating the discharge capacity of a power battery also includes:

[0126] S600: Update the historical trip energy consumption information according to the preset estimation cycle and update the starting temperature using the real-time temperature during the target vehicle's driving process;

[0127] And according to the preset estimation period, all steps of the power battery discharge capacity estimation method are repeated during the driving process at the target driving mileage.

[0128] Therefore, the power battery discharge capacity estimation method provided by this invention not only predicts the battery discharge time and the heat released by the battery during the entire target driving range based on the current power battery status, speed information, energy consumption information, and mileage information obtained from the user's historical driving habits when the electric vehicle is about to start discharging, and estimates the power battery temperature during the driving cycle based on Joule's law and heat transfer between the battery and the air; but also iterates based on the real-time temperature of the power battery during driving, thereby further improving the accuracy of the predicted temperature for the target range, thus obtaining more accurate discharge capacity, driving range, and remaining power.

[0129] It should be noted that, as those skilled in the art will understand, the present invention does not limit the specific value of the preset estimation period. For example, in some embodiments, the preset estimation period can be based on travel time, such as every 1 minute, 5 minutes, 10 minutes, 20 minutes, or other values; in other embodiments, the preset estimation period can be based on travel distance, such as every 1 kilometer, 2 kilometers, 5 kilometers, 10 kilometers, or other values; in still other embodiments, it can be based on travel segments, such as every 1, 2, 3, or other number of navigation segments traveled. Those skilled in the art can extrapolate from the above description, and these will not be listed here in detail.

[0130] For example, please see Figure 3 , Figure 3 This is a schematic diagram of the data processing flow for a specific example of the power battery discharge capacity estimation method provided by the present invention. From... Figure 3 As can be seen in this example, the initial temperature T0 of the power battery is first obtained. The estimated driving time t is obtained based on the estimated mileage (i.e., the target driving mileage) and the average driving speed V. The estimated average current I is obtained based on the current cell voltage u, average energy consumption q, and the estimated driving time t. The cell internal resistance R is obtained based on the cell HPCC parameters. Next, the estimated heat generation Q is obtained based on the estimated driving time t, estimated average current I, and cell internal resistance R. Then, the predicted battery temperature rise Δt is obtained based on the estimated heat generation Q. Next, the predicted end temperature T1 (i.e., the predicted temperature for the target journey) is obtained based on the predicted battery temperature rise Δt and the initial temperature T0. Finally, the predicted discharge correction coefficient fac-e is obtained based on the predicted end temperature T1. Furthermore, during driving, the real-time temperature T2 of the power battery can be obtained according to a preset cycle, and the initial temperature T0 is updated using the real-time temperature T2. All the above steps are repeated until the estimated mileage ends (i.e., the vehicle stops). Further details can be found in [link to relevant documentation]. Figure 4 , Figure 4 This is a schematic diagram comparing the changes in discharge capacity before and after using the power battery discharge capacity estimation method provided by this invention, as well as during the actual discharge process. Figure 4 In the diagram, the blue curve represents the theoretical discharge capacity of a power battery (i.e., the discharge capacity while maintaining a constant cell temperature during discharge), the red curve represents the actual discharge process of the power battery, and the green curve represents the discharge process estimated using the power battery discharge capacity estimation method provided by this invention. Figure 4 It is easy to see that by using the power battery discharge capacity prediction method provided by this invention to obtain the predicted discharge correction coefficient and correct the discharge capacity, the problem of the increased discharge capacity caused by the BMS's inability to predict the rise in battery temperature and the problem of the predicted driving range being too short can be eliminated. This can improve the control accuracy of the BMS system and the battery's utilization efficiency, thereby reducing the probability of cell damage and improving the user's driving experience.

[0131] A second embodiment of the present invention provides a vehicle controller, which includes a discharge capacity estimation device. Specifically, please refer to... Figure 5 , Figure 5 This is a block diagram illustrating the discharge capacity estimation device for a vehicle controller according to a second embodiment of the present invention. Figure 5As can be seen, the discharge capacity estimation device includes an estimation parameter acquisition module 110, a heat generation estimation module 120, a temperature rise prediction module 130, a prediction temperature acquisition module 140, and a discharge capacity estimation module 150. Specifically, the estimation parameter acquisition module 110 is configured to acquire the current power battery status and historical mileage energy consumption information of the target vehicle; the current power battery status includes the initial temperature of the power battery. The heat generation estimation module 120 is configured to obtain the estimated heat generation based on the current power battery status, the historical mileage energy consumption information, and the target mileage. The temperature rise prediction module 130 is configured to obtain the first predicted temperature rise of the power battery based on the estimated heat generation, the cell attribute parameters, and the coolant attribute parameters of the power battery. The prediction temperature acquisition module 140 is configured to obtain the target mileage predicted temperature of the power battery based on the initial temperature and the first predicted temperature rise. The discharge capacity estimation module 150 is configured to obtain an estimated discharge correction coefficient based on the target travel predicted temperature and the correspondence between the cell temperature of the power battery and the discharge correction coefficient; and to obtain the estimated discharge capacity of the power battery based on the estimated discharge correction coefficient.

[0132] Since the vehicle controller provided by this invention and the power battery discharge capacity estimation method provided by this invention belong to the same inventive concept, the vehicle controller provided by this invention possesses at least all the advantages of the power battery discharge capacity estimation method provided by this invention. For details regarding the beneficial effects of the vehicle controller provided by this invention, please refer to the above description of the beneficial effects of the power battery discharge capacity estimation method provided by this invention; further details will not be repeated here. Furthermore, since the basic principle of the vehicle controller provided by this invention is the same as the basic principle of the power battery discharge capacity estimation method provided by this invention, for more detailed information regarding the parts of the vehicle controller provided by this invention not submitted in this embodiment, please refer to the above description of the power battery discharge capacity estimation method for adaptive understanding; further details will not be elaborated here.

[0133] It should be noted that, as those skilled in the art will understand, the present invention does not limit the specific implementation of the vehicle controller. For example, in some exemplary embodiments, the vehicle controller can reuse the relevant hardware resources of existing vehicle controllers in electric vehicles, such as reusing the battery management controller, i.e., modifying the system software of the battery management controller (such as the BMS system) so that the existing battery management controller can execute the power battery discharge capacity estimation method provided by the present invention. Obviously, the vehicle controller provided by the present invention can also reuse the hardware resources of other vehicle controllers besides the battery management controller, which will not be listed here. Furthermore, in some other exemplary embodiments, the vehicle controller provided by the present invention can also have independent hardware resources such as memory and processor, without being integrated with any existing vehicle controller of the vehicle.

[0134] Preferably, in some exemplary embodiments, please continue to refer to Figure 5 ,from Figure 5 It can also be seen that the vehicle controller's discharge capacity estimation device provided in this embodiment further includes a driving range estimation module 160. Specifically, the driving range estimation module 160 is configured to obtain the estimated driving range based on the estimated discharge capacity of the power battery and the estimated average driving speed of the target vehicle. With this configuration, since the estimated discharge capacity obtained by the vehicle controller's discharge capacity estimation device provided by this invention has high accuracy, the estimated driving range obtained based on the estimated discharge capacity and the estimated average driving speed also has high accuracy, thereby improving vehicle utilization efficiency, reducing user anxiety, and enhancing user-friendliness. For example, if a user initiates a 400km navigation journey, the actual discharge capacity of the electric vehicle's battery can support a driving range of 430km (i.e., the actual range supported by the battery). Before using the battery discharge capacity estimation method provided by this invention, the calculated discharge capacity is too low, resulting in a driving range of 350km (i.e., the driving range displayed to the user). Clearly, the current battery cannot reach the destination, inevitably causing user anxiety during the journey. However, with the battery discharge capacity estimation method provided by this invention, the calculated discharge capacity is more accurate, resulting in a driving range of 420km (i.e., the driving range displayed to the user). Obviously, this allows the user to reach their destination as planned. Therefore, by improving the accuracy of the discharge capacity, the user experience can be significantly improved.

[0135] It should be noted that, as those skilled in the art will understand, the present invention does not impose excessive limitations on the method of obtaining the estimated average driving speed. For example, in some embodiments, the estimated average driving speed can be obtained based on navigation information; in other embodiments, the estimated average driving speed can be obtained based on historical trip energy consumption information. Of course, other methods besides the two mentioned above can also be used to determine the average driving speed, which will not be listed here. Furthermore, for details on how to obtain the estimated driving range based on the estimated discharge capacity and the estimated average driving speed, please refer to the relevant content on how to obtain the driving range based on the discharge capacity and driving speed, which is well known to those skilled in the art. Due to space limitations, this article will not elaborate further on this.

[0136] Preferably, in some exemplary embodiments, please continue to refer to Figure 5 ,from Figure 5 It can be seen that the vehicle controller's discharge capacity estimation device provided in this embodiment also includes a remaining power estimation module 170. For example, the remaining power estimation module 170 is configured to obtain the estimated remaining power of the power battery based on the estimated discharge capacity and the theoretical discharge capacity (i.e., the discharge capacity where the cell temperature remains constant during the discharge process). With this configuration, the estimated discharge capacity obtained by the vehicle controller's discharge capacity estimation device provided in this embodiment has high accuracy. Therefore, the estimated remaining power obtained based on the estimated discharge capacity and the theoretical discharge capacity also has high accuracy, thereby improving vehicle utilization efficiency, reducing user anxiety, and enhancing user-friendliness. For example, the estimated remaining power is calculated using the following formula (8):

[0137] SOCT = Estimated discharge capacity ÷ Theoretical discharge capacity (8)

[0138] In equation (8) above, SOCT is the estimated remaining power.

[0139] A third embodiment of the present invention provides another vehicle controller, exemplarily described in [reference needed]. Figure 6 , Figure 6 This is a block diagram of the vehicle controller provided in this embodiment of the present invention. Figure 6As shown, the vehicle controller provided in this embodiment includes a processor 210 and a memory 220. The memory 220 stores a computer program. When the computer program is executed by the processor 210, it implements the power battery discharge capacity estimation method provided in any of the above embodiments. Since the vehicle controller provided in this embodiment and the power battery discharge capacity estimation method provided by this invention belong to the same inventive concept, the vehicle controller provided in this embodiment has at least all the advantages of the power battery discharge capacity estimation method provided by this invention. For details, please refer to the relevant description of the beneficial effects of the power battery discharge capacity estimation method above, which will not be repeated here.

[0140] For example, such as Figure 6 As shown, the vehicle controller may further include a communication interface 230 and a communication bus 240, wherein the processor 210, the communication interface 230, and the memory 220 communicate with each other via the communication bus 240. The communication bus 240 includes, but is not limited to, a CAN bus. For ease of illustration, only one thick line is used to represent it in the figure, but this does not mean that there is only one bus or one type of bus. The communication interface 230 is used for communication between the aforementioned vehicle controller (e.g., the battery management controller) and other vehicle controllers (e.g., the vehicle controller, the autonomous driving domain controller, the motor controller, etc., not shown in the figure). The communication bus 240 connects the aforementioned vehicle controller (e.g., the battery management controller) and other vehicle controllers (e.g., the motor controller, etc., not shown in the figure) into a closed-loop system, enabling each vehicle controller to communicate and transmit data in multiple operating states (parking state, charging state, starting state, running state, vehicle forward and reverse state, regenerative braking state, mechanical braking state, general fault state, major fault state), thereby realizing the vehicle control function.

[0141] The processor 210 referred to in this invention can be a microcontroller unit (MCU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor 210 is the control center of the vehicle controller, connecting various parts of the entire vehicle controller via various interfaces and lines.

[0142] The memory 220 can be used to store the computer program. The processor 210 implements various functions of the vehicle controller by running or executing the computer program stored in the memory 220 and calling the data stored in the memory 220.

[0143] The memory 220 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may 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), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0144] A fourth embodiment of the present invention provides a readable storage medium storing a computer program. When executed by a processor, the computer program can implement the power battery discharge capacity estimation method described above. Since the readable storage medium provided by the present invention and the power battery discharge capacity estimation method provided by the present invention belong to the same inventive concept, the readable storage medium provided by the present invention possesses at least all the advantages of the power battery discharge capacity estimation method provided by the present invention. For details regarding the beneficial effects of the readable storage medium provided by the present invention, please refer to the above description of the beneficial effects of the power battery discharge capacity estimation method provided by the present invention; further details will not be repeated here.

[0145] The readable storage medium of embodiments of the present invention can be any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (not exhaustive examples) of a computer-readable storage medium include: an electrical connection having one or more wires, a portable computer hard disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, apparatus, or device.

[0146] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0147] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0148] Compared with the prior art, the present invention provides a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium, which have the following advantages:

[0149] The present invention provides a method for estimating the discharge capacity of a power battery. First, based on the current state of the power battery of the target vehicle, historical energy consumption information (i.e., the user's driving habits), and Joule's law, the estimated heat generation of the power battery is calculated. Then, based on the estimated heat generation and relevant battery attribute parameters, the temperature rise generated by the power battery itself during vehicle operation (i.e., the first predicted temperature rise) is estimated. Next, based on the initial temperature of the power battery and the first predicted temperature rise, the target range predicted temperature of the power battery is obtained. Finally, based on the estimated battery temperature (i.e., the target range predicted temperature), a discharge capacity correction coefficient is obtained, thereby obtaining an accurate discharge capacity throughout the entire vehicle's usage. This invention improves the accuracy of the discharge capacity across the entire temperature range, laying a solid foundation for achieving accurate driving range at any temperature. This not only benefits the high performance, high efficiency, and operational safety of the battery pack but also improves vehicle utilization efficiency and reduces user anxiety.

[0150] Since the vehicle controller and readable storage medium provided by this invention belong to the same inventive concept as the power battery discharge capacity estimation method provided by this invention, the vehicle controller and readable storage medium provided by this invention have at least all the advantages of the power battery discharge capacity estimation method provided by this invention. For details on the beneficial effects of the vehicle controller and readable storage medium provided by this invention, please refer to the above description of the beneficial effects of the power battery discharge capacity estimation method provided by this invention, which will not be repeated here.

[0151] It should be noted that the apparatus and methods disclosed in the embodiments herein can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments herein. In this regard, each block in a flowchart or block diagram may represent a module, program, or part of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system to perform the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0152] In addition, the functional modules in the various embodiments of this article can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0153] The above description is merely a preferred embodiment of a method for estimating the discharge capacity of a power battery, a vehicle controller, and a readable storage medium provided by the present invention, and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure are within the protection scope of the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A method for predicting the discharge capacity of a power battery, characterized in that, The cell attribute parameters of the power battery include the total mass of all the cells of the power battery and the specific heat capacity of the cells; The coolant properties include the mass of the coolant in the power battery and the specific heat capacity of the coolant; The prediction method includes: The system acquires the current battery status and historical energy consumption information of the target vehicle. The current battery status includes the initial temperature and current cell voltage of the battery. The historical energy consumption information includes the average driving speed and average energy consumption of the target vehicle. The estimated heat generation is obtained based on the current cell voltage, target driving range, average driving speed, and average energy consumption. The first predicted temperature rise of the power battery is obtained based on the estimated heat generation, the total mass of all the battery cells, the specific heat capacity of the battery cells, the mass of the coolant, and the specific heat capacity of the coolant. Based on the initial temperature and the first predicted temperature rise, the target range predicted temperature of the power battery is obtained. Based on the predicted temperature of the target travel distance and the correspondence between the cell temperature of the power battery and the discharge correction coefficient, the estimated discharge correction coefficient is obtained; and based on the estimated discharge correction coefficient, the estimated discharge capacity of the power battery is obtained.

2. The method for estimating the discharge capacity of a power battery according to claim 1, characterized in that, The historical mileage energy consumption information includes the historical mileage information of the target vehicle; before obtaining the estimated heat generation based on the current power battery status, the historical mileage energy consumption information, and the target mileage, the estimation method further includes: The target mileage is obtained based on the historical travel information; or the navigation information of the target vehicle is obtained, and the navigation mileage of the navigation information is used as the target mileage.

3. The method for estimating the discharge capacity of a power battery according to claim 1, characterized in that, The step of obtaining the estimated heat generation based on the current cell voltage, the target driving range, the average driving speed, and the average energy consumption includes: The estimated travel time is obtained based on the target mileage and the average speed. The estimated average current is obtained based on the current cell voltage, the estimated driving time, and the average energy consumption. The estimated heat generation is obtained based on the estimated average current, the internal resistance of each cell, the number of cells in the power battery, and the estimated driving time.

4. The method for estimating the discharge capacity of a power battery according to claim 2, characterized in that, Before obtaining the target range prediction temperature of the power battery based on the initial temperature and the first predicted temperature rise, the estimation method further includes: Obtain the ambient temperature; and based on the convective heat transfer coefficient, the surface area of ​​the power battery pack, the initial temperature, and the ambient temperature, obtain the amount of heat loss dissipated into the environment. Calculate the difference between the estimated heat generation and the heat loss, and based on the difference, the cell attribute parameters of the power battery, and the coolant attribute parameters, obtain the second predicted temperature rise of the power battery; The step of obtaining the target range prediction temperature of the power battery based on the initial temperature and the first predicted temperature rise includes: The target range prediction temperature of the power battery is obtained based on the initial temperature and the second predicted temperature rise.

5. The method for estimating the discharge capacity of a power battery according to claim 1, characterized in that, The prediction method further includes: The historical trip energy consumption information is updated according to a preset estimation cycle, and the starting temperature is updated using the real-time temperature during the target vehicle's driving process. And according to the preset estimation period, all steps of the power battery discharge capacity estimation method are repeated during the driving process at the target driving mileage.

6. A vehicle controller, characterized in that, The device includes a discharge capacity estimation device or a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the power battery discharge capacity estimation method according to any one of claims 1 to 5. The battery cell attribute parameters of the power battery include the total mass of all the battery cells and the specific heat capacity of the battery cells; the coolant attribute parameters include the mass of the coolant of the power battery and the specific heat capacity of the coolant; the discharge capacity prediction device includes: a prediction parameter acquisition module, a heat generation prediction module, a temperature rise prediction module, a prediction temperature acquisition module, and a discharge capacity prediction module. The estimated parameter acquisition module is configured to acquire the current power battery status and historical travel energy consumption information of the target vehicle; the current power battery status includes the initial temperature and current cell voltage of the power battery; the historical travel energy consumption information includes the average driving speed and average energy consumption of the target vehicle. The heat generation estimation module is configured to obtain the estimated heat generation based on the cell voltage, the target driving mileage, the average driving speed, and the average energy consumption. The temperature rise prediction module is configured to obtain a first predicted temperature rise of the power battery based on the estimated heat generation, the total mass of all the battery cells, the specific heat capacity of the battery cells, the mass of the coolant, and the specific heat capacity of the coolant. The predicted temperature acquisition module is configured to obtain the target travel predicted temperature of the power battery based on the initial temperature and the first predicted temperature rise. The discharge capacity estimation module is configured to obtain an estimated discharge correction coefficient based on the predicted temperature of the target travel and the correspondence between the cell temperature of the power battery and the discharge correction coefficient; and to obtain the estimated discharge capacity of the power battery based on the estimated discharge correction coefficient.

7. The vehicle controller according to claim 6, characterized in that, The discharge capacity estimation device also includes a driving range estimation module and / or a remaining power estimation module. The driving range estimation module is configured to obtain the estimated driving range based on the estimated discharge capacity of the power battery and the estimated average driving speed of the target vehicle. The remaining power estimation module is configured to obtain the estimated remaining power of the power battery based on the estimated discharge capacity and the theoretical discharge capacity.

8. A readable storage medium, characterized in that, The readable storage medium stores a computer program, which, when executed by a processor, implements the method for estimating the discharge capacity of a power battery as described in any one of claims 1 to 5.

Images