Battery energy management method and device based on balance equation, equipment and storage medium

Abstract

The invention provides a battery energy management method, device and equipment based on a balance equation and a storage medium, and the method comprises the steps: firstly obtaining state parameters of each battery unit of a battery pack in a use process in real time, and carrying out the preprocessing of the state parameters; thirdly, an equilibrium equation is built according to the preprocessed state parameters, an objective function is built according to the equilibrium equation, heat balance deviation, capacity weight and an internal resistance penalty term in the objective function are subjected to weighted calculation to obtain total deviation, the total deviation is optimized and solved, and an initial energy distribution coefficient is generated; and finally, correcting the initial energy distribution coefficient according to the self-discharge rate of the battery unit, and adjusting the charging and discharging current of each battery unit according to the corrected energy distribution coefficient, thereby solving the problem of low energy utilization rate of the battery pack caused by parameter imbalance among the battery units of the battery pack.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicles, and in particular to a battery energy management method, device, equipment and storage medium based on a balance equation. Background Art

[0002] With the widespread application of lithium batteries in electronic devices and electric vehicles, their energy management has become a key issue. There may be inconsistencies between the individual battery cells of lithium batteries, including differences in capacity, internal resistance, self-discharge rate, etc. This inconsistency will lead to a decline in the overall performance of the battery pack, such as reduced energy utilization and shortened service life. Although the current lithium battery management system can monitor and control the status of the battery to a certain extent, it is not effective in handling the imbalance problem between battery cells.

[0003] In view of this, this application is filed. Summary of the invention

[0004] The present invention discloses a battery energy management method, device, equipment and storage medium based on a balance equation, aiming to solve the problem of low energy utilization of a battery pack caused by parameter imbalance between battery cells of the battery pack.

[0005] The first embodiment of the present invention provides a battery energy management method based on a balance equation, comprising:

[0006] Acquire the state parameters of each battery cell of the battery pack in real time during use, and pre-process the state parameters;

[0007] A balance equation is constructed according to the state parameters after preprocessing, and an objective function is established according to the balance equation, a total deviation is obtained by weighted calculation of the thermal balance deviation, the capacity weight and the internal resistance penalty term in the objective function, and the total deviation is optimized and solved to generate an initial energy distribution coefficient;

[0008] The initial energy distribution coefficient is corrected according to the self-discharge rate of the battery cell, and the charge and discharge current of each battery cell is adjusted according to the corrected energy distribution coefficient.

[0009] Preferably, the expression of the equilibrium equation is:

[0010] I 2 Rt-IT(dU / dT)t-△TAht=Cm(T1-T0)+1 / 2EVe 2 thermal

[0011] Where R is the internal resistance of the lithium battery, t is the charge and discharge time, (dU / dT) is the temperature entropy coefficient, the current I is positive for the charging process and negative for the discharge process, T is the temperature of the lithium battery, which takes the average surface temperature of the lithium battery to characterize the temperature of the lithium battery, (T1-T0) is the temperature difference between the current moment and the previous moment of the lithium battery, △T is the difference between the surface temperature and the ambient temperature, A is the heat dissipation surface area of ​​the lithium battery, h is the Newton heat dissipation coefficient, C is the specific heat capacity of the lithium battery, m is the mass of the lithium battery, E is the Young's modulus, V is the volume of the lithium battery, e thermal is thermal strain.

[0012] Preferably, the total deviation is obtained by weighted calculation of the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function, specifically:

[0013] Calculate the capacity weight of each battery cell, where the capacity weight is the ratio of the capacity of the battery cell to the maximum capacity of all battery cells;

[0014] Calculate the internal resistance penalty term of each battery cell, where the internal resistance penalty term is the ratio of the internal resistance of the battery cell to the minimum internal resistance of all battery cells;

[0015] The thermal balance deviation, capacity weight and internal resistance penalty term are multiplied together to obtain the weighted deviation of the battery cell, and the weighted deviations of all battery cells are summed to obtain the total deviation.

[0016] Preferably, the thermal balance deviation is the difference between the algebraic sum of Joule heat, reversible heat and convection heat and the algebraic sum of heat accumulation and thermal stress.

[0017] Preferably, the initial energy distribution coefficient is corrected according to the self-discharge rate of the battery cell, specifically:

[0018] Obtain the minimum self-discharge rate of all battery cells as a reference value;

[0019] Calculate the self-discharge rate correction factor of each battery cell, where the correction factor is the ratio of the reference value to the self-discharge rate of the battery cell;

[0020] The initial energy distribution coefficient is multiplied by the corresponding correction factor to obtain a corrected distribution coefficient;

[0021] The corrected distribution coefficient is normalized to obtain the final energy distribution coefficient.

[0022] A second embodiment of the present invention provides a battery energy management device based on a balance equation, comprising:

[0023] A state parameter preprocessing unit, used to obtain the state parameters of each battery cell of the battery pack in real time during use, and preprocess the state parameters;

[0024] An energy distribution coefficient generating unit is used to construct a balance equation according to the preprocessed state parameters, establish an objective function according to the balance equation, perform weighted calculation on the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function to obtain a total deviation, optimize and solve the total deviation, and generate an initial energy distribution coefficient;

[0025] The current adjustment unit is used to correct the initial energy distribution coefficient according to the self-discharge rate of the battery cell, and adjust the charge and discharge current of each battery cell according to the corrected energy distribution coefficient.

[0026] The third embodiment of the present invention provides a battery energy management device based on a balance equation, including a memory and a processor, wherein the memory stores a computer program, and the computer program can be executed by the processor to implement a battery energy management method based on a balance equation as described in any one of the above.

[0027] The fourth embodiment of the present invention provides a computer-readable storage medium, characterized in that a computer program is stored therein, and the computer program can be executed by a processor of a device where the computer-readable storage medium is located to implement a battery energy management method based on a balance equation as described in any one of the above items.

[0028] A battery energy management method, device, equipment and storage medium based on a balance equation provided by the present invention first obtains the state parameters of each battery cell of a battery pack in real time during use, and preprocesses the state parameters; then, a balance equation is constructed according to the preprocessed state parameters, and an objective function is established according to the balance equation, and the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function are weightedly calculated to obtain a total deviation, and the total deviation is optimized and solved to generate an initial energy distribution coefficient; finally, the initial energy distribution coefficient is corrected according to the self-discharge rate of the battery cell, and the charge and discharge current of each battery cell is adjusted according to the corrected energy distribution coefficient, thereby solving the problem of low energy utilization of the battery pack due to parameter imbalance between the battery cells of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of a battery energy management method based on a balance equation provided by the first embodiment of the present invention;

[0030] Figure 2 It is a module schematic diagram of a battery energy management device based on a balance equation provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] It should be clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0035] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0037] The "first\second" mentioned in the embodiments is only to distinguish similar objects, and does not represent a specific order for the objects. It is understandable that the "first\second" can be interchanged with the specific order or sequence where permitted. It should be understood that the objects distinguished by "first\second" can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than those illustrated or described herein.

[0038] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] The present invention discloses a battery energy management method, device, equipment and storage medium based on a balance equation, aiming to solve the problem of low energy utilization of a battery pack caused by parameter imbalance between battery cells of the battery pack.

[0040] The first embodiment of the present invention provides a battery energy management method based on a balance equation, which can be executed by a battery energy management device based on a balance equation (hereinafter referred to as a management device), and in particular, executed by one or more processors in the management device to implement at least the following steps:

[0041] S101, acquiring state parameters of each battery cell of the battery pack in real time during use, and preprocessing the state parameters;

[0042] In this embodiment, the management device may be the vehicle controller of the electric vehicle, which can communicate with the battery pack in real time to obtain the status parameters of each battery cell. The management device may be installed with a corresponding operating system and application software, and the functions required by this embodiment can be implemented through the combination of the operating system and application software.

[0043] It should be noted that the present invention configures a high-precision multimodal sensor array on each battery cell, including but not limited to voltage sensors, current sensors, temperature sensors, pressure sensors and strain sensors. The multimodal sensor array adopts a distributed layout to capture the status information of the battery cell in all directions. Among them, the voltage sensor adopts a high-precision differential measurement circuit, which can achieve microvolt-level measurement accuracy; the current sensor adopts a hybrid sensing solution combining the Hall effect and the magnetoresistance effect, in order to improve the measurement accuracy under high current conditions; the temperature sensor adopts a redundant design of thermocouples and thermistors in parallel, aiming to improve the temperature measurement accuracy and measurement reliability.

[0044] In a possible implementation of the present invention, after the battery pack is powered on, a preliminary judgment is made on the state data collected by the multimodal sensor array. When it is determined that the state data is erroneous or the parameters are missing, an error alarm is issued, otherwise the process of preprocessing the state parameters is entered. Among them, the preprocessing process adopts a combination of median filtering and Kalman filtering to remove measurement noise, and the combined filtering method can better balance the filtering effect. Secondly, for temperature data, a periodic interference elimination algorithm based on Fourier transform is introduced to effectively eliminate the influence of ambient temperature fluctuations on the measurement results. Furthermore, in order to ensure the reliability of the data, the management device can establish a probability distribution model of each parameter based on historical data. When the collected data deviates significantly from the normal distribution range, the data correction process will be triggered. Data correction adopts a prediction model based on deep learning, and the neural network obtained by training historical data is used to predict the reasonable value of abnormal data.

[0045] S102, constructing a balance equation according to the preprocessed state parameters, and establishing an objective function according to the balance equation, performing weighted calculation on the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function to obtain a total deviation, optimizing and solving the total deviation, and generating an initial energy allocation coefficient;

[0046] It should be noted that the existing lithium battery thermal management systems usually use simplified thermal models, which are difficult to accurately describe the complex thermal behavior of the battery during actual operation. This leads to poor thermal management effects and affects battery performance and life.

[0047] In a possible implementation of the present invention, the established equilibrium equation comprehensively considers various thermal effects of the lithium battery during operation, including Joule heat, reversible heat, heat conduction, heat accumulation, and thermal stress. The expression of the equilibrium equation is: 2 Rt-IT(dU / dT)t-△TAht=Cm(T1-T0)+1 / 2EVe 2 thermal

[0048] Where R is the internal resistance of the lithium battery, t is the charge and discharge time, (dU / dT) is the temperature entropy coefficient, the current I is positive for the charging process and negative for the discharge process, T is the temperature of the lithium battery, which takes the average surface temperature of the lithium battery to characterize the temperature of the lithium battery, (T1-T0) is the temperature difference between the current moment and the previous moment of the lithium battery, △T is the difference between the surface temperature and the ambient temperature, A is the heat dissipation surface area of ​​the lithium battery, h is the Newton heat dissipation coefficient, C is the specific heat capacity of the lithium battery, m is the mass of the lithium battery, E is the Young's modulus, V is the volume of the lithium battery, e thermal is the thermal strain

[0049] The left side of the equation describes the process of heat generation and dissipation, while the right side characterizes the accumulation and conversion effect of heat inside the battery.

[0050] Specifically, the first term I in the equation 2Rt represents Joule heat, which reflects the heat generated by the current passing through the internal resistance of the battery. The dynamic internal resistance model is adopted, and the equivalent internal resistance R of the battery under different working conditions is obtained through real-time measurement and calculation. The second term IT(dU / dT)t describes the reversible thermal effect, where (dU / dT) is the temperature entropy coefficient. The temperature entropy coefficient under different states of charge (SOC) is measured, and the functional relationship between the temperature entropy coefficient and SOC is established. It overcomes the limitation of treating the temperature entropy coefficient as a constant in the traditional model, making the calculation of reversible heat more accurate. At the same time, different current sign conventions are used in the equation for the charging and discharging process (charging is positive and discharging is negative), which enables the equation to accurately reflect the differences in thermal behavior of the battery under different working modes. The third term △TAht represents convective heat transfer, where △T is the temperature difference between the battery surface and the environment. The adaptive heat transfer coefficient h is introduced, which will be dynamically adjusted according to factors such as ambient temperature and air flow rate. This enables the model to better adapt to different working environments and improves the accuracy of heat dissipation calculations. In addition, this embodiment also takes into account the uneven distribution of the battery surface temperature, and more accurately represents the actual temperature state of the battery by taking an average of the multi-point temperature measurements.

[0051] The first term Cm(T1-T0) on the right side of the equation describes the heat accumulation effect. In this embodiment, the specific heat capacity C value of the battery at different temperatures was obtained through calorimetric experiments, and a temperature dependence model was established. This overcomes the defect of treating the specific heat capacity as a constant in the traditional model and improves the accuracy of the heat accumulation calculation. The last term 1 / 2EVe 2 thermal The thermal strain energy is represented by the thermal strain energy. The traditional model often ignores the influence of thermal strain on the thermal behavior of the battery. However, in this embodiment, the thermal-mechanical coupling effect of the battery is accurately described by introducing the thermal strain energy. The thermal strain state of the battery can be monitored in real time through the in-situ strain measurement technology.

[0052] It should be noted that existing lithium battery energy distribution methods often only consider a single factor for weight calculation, which is difficult to fully reflect the differences between battery cells, resulting in unreasonable energy distribution and affecting the overall performance of the battery pack.

[0053] The present invention innovatively proposes a dual weighting mechanism based on capacity weight and internal resistance penalty. For the calculation of capacity weight, the management device first obtains the capacity values ​​of all cells in the battery pack, finds the maximum capacity as the reference value, and then calculates the ratio of the capacity of each battery cell to the reference value as the capacity weight. This is mainly to take into account the capacity difference between battery cells, so that battery cells with larger capacity can bear more energy distribution, thereby improving the energy utilization efficiency of the battery pack.

[0054] In the internal resistance penalty term, this embodiment adopts an adaptive weight calculation method. The management device first finds the battery cell with the smallest internal resistance in the battery pack, takes its internal resistance value as the benchmark, and then calculates the ratio of the internal resistance of each battery cell to the benchmark value as the internal resistance penalty term. The energy distribution of battery cells with larger internal resistance is limited by a larger penalty factor, which effectively avoids the problem of local overheating.

[0055] The present invention adopts a method of item-by-item accumulation when calculating the thermal balance deviation. Specifically, firstly, the heat generation item is calculated, including the algebraic sum of Joule heat (I2Rt), reversible heat (IT(dU / dT)t) and convection heat (△TAht); then the heat storage item is calculated, that is, the algebraic sum of heat accumulation (Cm(T1-T0)) and thermal stress (1 / 2EVe2thermal); finally, the difference between these two items is taken as the thermal balance deviation. Not only the generation and loss of heat is taken into account, but also the storage and conversion of heat inside the battery is included, so that the thermal balance deviation can more comprehensively reflect the actual thermal state of the battery.

[0056] In the final weighted calculation, the thermal balance deviation, capacity weight, and internal resistance penalty terms are coupled. By multiplying these three terms, the weighted deviation of each battery cell is obtained, ensuring that the three factors can restrict and influence each other. Subsequently, the management device sums the weighted deviations of all battery cells to obtain a total deviation value that reflects the state of the entire battery pack. This multi-factor coupled calculation method enables the system to fully consider the individual characteristic differences of battery cells while ensuring thermal balance.

[0057] S103, correcting the initial energy distribution coefficient according to the self-discharge rate of the battery cell, and adjusting the charge and discharge current of each of the battery cells according to the corrected energy distribution coefficient.

[0058] It should be noted that the existing lithium battery energy distribution method usually ignores the self-discharge characteristics of the battery cells, which leads to a gradual increase in the energy difference between the battery cells during long-term use, affecting the overall performance of the battery pack.

[0059] In a possible implementation of the present invention, a self-discharge rate correction mechanism is introduced. The management device first measures the self-discharge characteristics, that is, monitors each battery cell for a long time at different temperatures and charge states to obtain its self-discharge rate characteristic curve. The influence of temperature on self-discharge is taken into account, and a correlation model between self-discharge rate and battery aging degree is established, so that the acquisition of self-discharge rate is more accurate and reliable. Among the self-discharge rate data of all battery cells, the minimum value is selected as the benchmark to ensure that there will be no over-compensation problem during the correction process.

[0060] In the calculation of the correction factor, an adaptive ratio calculation method is adopted. The correction factor of each battery cell is obtained by performing a ratio operation between the minimum self-discharge rate (reference value) and the self-discharge rate of each battery cell. This design enables battery cells with higher self-discharge rates to obtain smaller correction factors, thereby obtaining less energy distribution during energy distribution, which effectively prevents safety hazards caused by energy accumulation in battery cells with high self-discharge rates.

[0061] This embodiment adopts a dynamic compensation strategy in the process of correcting the energy distribution coefficient. The management device multiplies the initial energy distribution coefficient by the corresponding self-discharge rate correction factor to obtain the corrected distribution coefficient. This ensures that the self-discharge characteristics can directly affect the results of energy distribution, so that the management device can automatically compensate for the energy loss caused by self-discharge when performing energy distribution. In particular, the management device also establishes a dynamic update mechanism for the correction factor, which can adjust the correction strategy in real time according to the changes in the self-discharge characteristics of the battery cell.

[0062] See also Figure 2 The second embodiment of the present invention provides a battery energy management device based on a balance equation, comprising:

[0063] The state parameter preprocessing unit 201 is used to obtain the state parameters of each battery cell of the battery pack in real time during use and preprocess the state parameters;

[0064] The energy distribution coefficient generating unit 202 is used to construct a balance equation according to the preprocessed state parameters, establish an objective function according to the balance equation, perform weighted calculation on the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function to obtain a total deviation, optimize and solve the total deviation, and generate an initial energy distribution coefficient;

[0065] The current adjustment unit 203 is used to correct the initial energy distribution coefficient according to the self-discharge rate of the battery cell, and adjust the charge and discharge current of each battery cell according to the corrected energy distribution coefficient.

[0066] The third embodiment of the present invention provides a battery energy management device based on a balance equation, including a memory and a processor, wherein the memory stores a computer program, and the computer program can be executed by the processor to implement a battery energy management method based on a balance equation as described in any one of the above.

[0067] The fourth embodiment of the present invention provides a computer-readable storage medium, characterized in that a computer program is stored therein, and the computer program can be executed by a processor of a device where the computer-readable storage medium is located to implement a battery energy management method based on a balance equation as described in any one of the above items.

[0068] A battery energy management method, device, equipment and storage medium based on a balance equation provided by the present invention first obtains the state parameters of each battery cell of a battery pack in real time during use, and preprocesses the state parameters; then, a balance equation is constructed according to the preprocessed state parameters, and an objective function is established according to the balance equation, and the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function are weightedly calculated to obtain a total deviation, and the total deviation is optimized and solved to generate an initial energy distribution coefficient; finally, the initial energy distribution coefficient is corrected according to the self-discharge rate of the battery cell, and the charge and discharge current of each battery cell is adjusted according to the corrected energy distribution coefficient, thereby solving the problem of low energy utilization of the battery pack due to parameter imbalance between the battery cells of the battery pack.

[0069] Exemplarily, the computer program described in the third and fourth embodiments of the present invention may be divided into one or more modules, and the one or more modules are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the battery energy management device based on the balance equation. For example, the device described in the second embodiment of the present invention.

[0070] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the battery energy management method based on the balance equation, and uses various interfaces and lines to connect the various parts of the battery energy management method based on the balance equation.

[0071] The memory can be used to store the computer program and / or module, and the processor realizes various functions of a battery energy management method based on a balance equation by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, a text conversion function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, text message data, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0072] Wherein, if the implemented module is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0073] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0074] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A battery energy management method based on a balance equation, characterized in that: include: Acquire the state parameters of each battery cell of the battery pack in real time during use, and pre-process the state parameters; A balance equation is constructed according to the state parameters after preprocessing, and an objective function is established according to the balance equation, a total deviation is obtained by weighted calculation of the thermal balance deviation, the capacity weight and the internal resistance penalty term in the objective function, and the total deviation is optimized and solved to generate an initial energy distribution coefficient; The initial energy distribution coefficient is corrected according to the self-discharge rate of the battery cell, and the charge and discharge current of each battery cell is adjusted according to the corrected energy distribution coefficient.

2. A battery energy management method based on a balance equation according to claim 1, characterized in that: The expression of the equilibrium equation is: I 2 Rt-IT(dU / dT)t-△TAht=Cm(T1-T0)+1 / 2EVe 2 thermal Where R is the internal resistance of the lithium battery, t is the charge and discharge time, (dU / dT) is the temperature entropy coefficient, the current I is positive for the charging process and negative for the discharge process, T is the temperature of the lithium battery, which takes the average surface temperature of the lithium battery to characterize the temperature of the lithium battery, (T1-T0) is the temperature difference between the current moment and the previous moment of the lithium battery, △T is the difference between the surface temperature and the ambient temperature, A is the heat dissipation surface area of ​​the lithium battery, h is the Newton heat dissipation coefficient, C is the specific heat capacity of the lithium battery, m is the mass of the lithium battery, E is the Young's modulus, V is the volume of the lithium battery, e thermal is thermal strain.

3. The battery energy management method based on the balance equation according to claim 1, characterized in that: The total deviation is obtained by weighted calculation of the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function, specifically: Calculate the capacity weight of each battery cell, where the capacity weight is the ratio of the capacity of the battery cell to the maximum capacity of all battery cells; Calculate the internal resistance penalty term of each battery cell, where the internal resistance penalty term is the ratio of the internal resistance of the battery cell to the minimum internal resistance of all battery cells; The thermal balance deviation, capacity weight and internal resistance penalty term are multiplied together to obtain the weighted deviation of the battery cell, and the weighted deviations of all battery cells are summed to obtain the total deviation.

4. The battery energy management method based on the balance equation according to claim 1, characterized in that: The thermal balance deviation is the difference between the algebraic sum of Joule heat, reversible heat and convection heat and the algebraic sum of heat accumulation and thermal stress.

5. The battery energy management method based on the balance equation according to claim 1, characterized in that: The initial energy distribution coefficient is modified according to the self-discharge rate of the battery cell, specifically: Obtain the minimum self-discharge rate of all battery cells as a reference value; Calculate the self-discharge rate correction factor of each battery cell, where the correction factor is the ratio of the reference value to the self-discharge rate of the battery cell; The initial energy distribution coefficient is multiplied by the corresponding correction factor to obtain a corrected distribution coefficient; The corrected distribution coefficient is normalized to obtain the final energy distribution coefficient.

6. A battery energy management device based on a balance equation, characterized in that: include: A state parameter preprocessing unit, used to obtain the state parameters of each battery cell of the battery pack in real time during use, and preprocess the state parameters; An energy distribution coefficient generating unit is used to construct a balance equation according to the preprocessed state parameters, establish an objective function according to the balance equation, perform weighted calculation on the thermal balance deviation, capacity weight and internal resistance penalty term in the objective function to obtain a total deviation, optimize and solve the total deviation, and generate an initial energy distribution coefficient; The current adjustment unit is used to correct the initial energy distribution coefficient according to the self-discharge rate of the battery cell, and adjust the charge and discharge current of each battery cell according to the corrected energy distribution coefficient.

7. A battery energy management device based on a balance equation, characterized in that: It comprises a memory and a processor, wherein the memory stores a computer program, and the computer program can be executed by the processor to implement a battery energy management method based on a balance equation as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: A computer program is stored, and the computer program can be executed by a processor of the device where the computer-readable storage medium is located to implement a battery energy management method based on a balance equation as described in any one of claims 1 to 5.

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