Battery pack dynamic equalization method and device

Abstract

The invention discloses a battery pack dynamic equalization method and device, and the method comprises the steps: calculating a target equalization threshold value according to a preset initial equalization threshold value and a battery health state collected in real time; when it is detected that the voltage difference between any two single batteries exceeds a target equalization threshold value, determining at least one single battery in the two single batteries as a battery to be equalized; and performing equalization operation on the at least one battery to be equalized so as to reduce the voltage difference between the single batteries in the battery pack. According to the invention, the equalization threshold is dynamically adjusted to adapt to the change of the health state of the battery, the adaptive improvement of equalization control is realized, the expansion of monomer difference is effectively inhibited, the service life of the battery pack is prolonged, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and in particular to a method and apparatus for dynamic balancing of battery packs. Background Technology

[0002] During the operation of an energy storage system, the battery pack gradually ages with long-term use and continuous charging and discharging, leading to increased internal impedance, capacity decay, and a significant increase in the performance differences between individual cells. Traditional energy storage battery management systems (BMS) mostly use a fixed voltage difference threshold for equalization control, that is, when the voltage difference between any two individual cells in the battery pack exceeds this fixed threshold, the equalization operation is initiated.

[0003] However, this fixed threshold equalization strategy has significant shortcomings: in the early stages of battery life, the performance differences between individual cells are small, and the fixed threshold can meet the requirements; but as the battery ages and the differences between individual cells increase, the fixed threshold is difficult to adapt to changes, easily leading to untimely or over-equalization, which in turn causes overcharging, over-discharging, or unnecessary energy loss in individual cells, accelerating battery aging and reducing the overall performance and lifespan of the battery pack. Therefore, the traditional fixed threshold strategy cannot meet the requirements for long-term efficient operation of battery packs, and there is an urgent need for a method that can dynamically adjust the equalization threshold in real time based on the battery state of health (SOH) and ambient temperature to achieve more precise and efficient battery management.

[0004] The information disclosed in this background section is included only to enhance the understanding of the context of this disclosure, and therefore may contain information that does not constitute relevant technology currently known to those skilled in the art. Summary of the Invention

[0005] This application provides a method and apparatus for dynamic balancing of battery packs to solve the problems of untimely or over-balancing under traditional fixed threshold strategies.

[0006] The technical solution adopted in this application is as follows: In a first aspect, this application provides a dynamic balancing method for a battery pack, which is applied to a battery pack comprising multiple individual cells. The method includes: The target equalization threshold is calculated based on the preset initial equalization threshold and the real-time battery health status. When the voltage difference between any two individual cells exceeds the target equalization threshold, at least one of the two individual cells is identified as the cell to be equalized. Perform a balancing operation on at least one cell to be balanced in order to reduce the voltage difference between individual cells in the battery pack.

[0007] The battery pack dynamic balancing method provided in this application can dynamically adjust the balancing threshold according to the real-time health status of the battery pack, thereby more accurately identifying the individual battery cells that need balancing and achieving targeted balancing operations. Compared with the existing technology that uses a fixed balancing threshold, this method can effectively improve the flexibility and adaptability of battery pack balancing, help reduce the voltage difference between individual cells, extend the overall lifespan of the battery pack, and improve system safety and reliability.

[0008] In conjunction with the first aspect, in one possible implementation, the target equalization threshold is calculated based on a pre-set initial equalization threshold and the real-time collected battery health status, including: The first coefficient is determined based on the real-time collected battery health status. The second coefficient is determined based on the real-time collected ambient temperature. The target equilibrium threshold is calculated based on the preset initial equilibrium threshold, the first coefficient, and the second coefficient.

[0009] This application achieves more precise and intelligent equalization control by dynamically adjusting the equalization threshold based on battery health status and ambient temperature. Compared to traditional fixed threshold methods, it more effectively addresses battery aging and environmental changes, improving battery pack consistency and lifespan, and enhancing safety and reliability.

[0010] In conjunction with the first aspect, in one possible implementation, the target equilibrium threshold is calculated by: obtaining the target equilibrium threshold based on the following formula: ; Among them, V t V0 is the target equalization threshold, V0 is the preset initial equalization threshold, d represents the degree of degradation of battery health status, and the value range is 0~100%. When the battery is in the new battery stage, d is 0, T is the real-time collected ambient temperature, T0 is the reference temperature value, m is the first parameter, n is the second parameter, and k is the scaling factor.

[0011] This application introduces a dynamic equalization threshold adjustment formula based on battery state of health (SOH) and ambient temperature (T), thereby achieving adaptive adjustment of the equalization threshold and improving equalization accuracy and adaptability.

[0012] In conjunction with the first aspect, in one possible implementation, when the voltage difference between any two individual cells is detected to exceed the target equalization threshold, at least one of the two individual cells is identified as a cell to be equalized, including: When the voltage difference between any two individual cells exceeds the target equalization threshold, the duration for which the voltage difference exceeds the target equalization threshold is obtained. When the duration reaches the preset time, at least one of the two individual cells is identified as the cell to be balanced.

[0013] This application effectively avoids misjudgments caused by instantaneous noise or occasional fluctuations by monitoring the duration for which the voltage difference exceeds the target equalization threshold, thereby improving the accuracy of equalization judgment. Only when the voltage difference persists for a preset duration is the battery identified as needing equalization. This helps reduce unnecessary equalization operations, lower energy loss, and extend battery life.

[0014] In conjunction with the first aspect, in one possible implementation, identifying at least one of the two individual cells as the cell to be balanced includes: The cell with the highest voltage among the two individual cells is identified as the cell to be balanced. And / or, determine the cell with the lowest voltage among the two individual cells as the cell to be balanced.

[0015] This application allows for targeted selection of individual cells with large voltage differences, enabling flexible adjustment of the balancing strategy according to actual needs. This makes the balancing process more accurate and efficient, thereby improving the safety, reliability, and lifespan of the battery pack.

[0016] In conjunction with the first aspect, in one possible implementation, the method further includes: The equalization operation stops when the voltage difference between two individual cells is updated to be less than or equal to the target equalization threshold.

[0017] This application prevents over-balancing by stopping the balancing operation in a timely manner when the voltage difference between two individual cells is updated to be less than or equal to the target balancing threshold, thereby avoiding energy waste and additional damage to the cells caused by the balancing operation.

[0018] In conjunction with the first aspect, in one possible implementation, the method further includes: Real-time monitoring of at least one parameter among charge-discharge cycle number, capacity, and internal resistance of a single battery cell; The battery health status of a single cell is obtained based on at least one parameter.

[0019] This application obtains the state of health (SOH) of a single battery cell by real-time monitoring of at least one parameter among charge-discharge cycle count, capacity, and internal resistance. This enables a more comprehensive and accurate assessment of battery performance and usage status. This not only helps to promptly identify and eliminate battery cells with abnormalities or performance degradation but also provides data support for optimizing subsequent equalization strategies.

[0020] In conjunction with the first aspect, in one possible implementation, the battery health status of a single cell is obtained based on at least one parameter, including: The battery health status of a single cell is obtained based on its capacity and internal resistance, including: The capacity decay rate is determined based on the rated capacity and available capacity of a single cell; The internal resistance growth rate is determined based on the initial and current internal resistance of a single cell. The battery health status of a single cell is calculated based on the capacity decay rate, the internal resistance growth rate, and a preset weighting coefficient.

[0021] This application comprehensively evaluates the battery health status by combining capacity decay rate and internal resistance growth rate, achieving accurate diagnosis of battery performance and thus providing reliable data support for the optimization of subsequent equalization strategies.

[0022] Secondly, this application provides a battery pack dynamic balancing device. The battery pack dynamic balancing device includes a memory and a processor. The memory stores computer programs or instructions, which, when executed by the processor, implement the methods described in the first aspect or any possible implementation thereof.

[0023] Thirdly, this application provides a computer-readable storage medium. This storage medium stores a computer program or instructions that, when executed by a processor, implement the method described in the first aspect or any possible implementation thereof.

[0024] The beneficial effects of the second and third aspects described above can be referenced to the first aspect or any possible implementation thereof, and will not be elaborated upon here. Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations.

[0025] Other advantages, objectives and features of this application will be partly apparent from the description below, and partly understood by those skilled in the art through study and practice of this application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is one of the flowcharts of the battery pack dynamic balancing method provided in the embodiments of this application; Figure 2 This is the second flowchart of the battery pack dynamic balancing method provided in the embodiments of this application; Figure 3 This is one of the structural schematic diagrams of the battery pack dynamic balancing device provided in the embodiments of this application; Figure 4 This is the second schematic diagram of the battery pack dynamic balancing device provided in the embodiments of this application. Detailed Implementation

[0028] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0029] The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. In this application, "at least one" means one or more, and "more than one" means two or more. The terms "first," "second," and other ordinal terms used in this application may be used to describe various constituent elements, but these constituent elements are not limited by these terms. The purpose of using these terms is solely to distinguish one constituent element from others and should not be construed as indicating or implying relative importance. For example, without departing from the scope of this application, a first constituent element may be named a second constituent element, and similarly, a second constituent element may be named a first constituent element.

[0030] Before introducing the embodiments of this application, the technical terms and background technology involved in this application will be introduced first.

[0031] During long-term operation of energy storage systems, individual battery cells gradually age due to continuous charging and discharging, exhibiting increased internal resistance, decreased capacity, and greater performance differences between cells. Traditional BMS (Battery Management Systems) often use fixed voltage difference thresholds for equalization control, which may meet initial needs. However, as batteries age, fixed thresholds become difficult to adapt to changes, easily leading to untimely or excessive equalization, resulting in overcharging, over-discharging, or energy loss, accelerating aging, and reducing battery pack life and performance. Therefore, fixed threshold strategies are insufficient to meet the requirements of efficient and long-term battery pack operation. There is an urgent need to dynamically adjust the equalization threshold based on the battery state of health (SOH) and ambient temperature to achieve more precise and efficient management.

[0032] In summary, the balancing control strategies in related technologies generally suffer from fixed thresholds and poor adaptability. To address these issues, this application provides a battery pack dynamic balancing method and apparatus that can adjust the balancing threshold in real time based on battery health status and environmental conditions, thereby improving the balancing effect and lifespan of the battery pack.

[0033] refer to Figure 1, Figure 1 This is one of the flowcharts of the battery pack dynamic balancing method provided in this application embodiment. It should be noted that this specification provides the operational steps of the method as described in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operational steps may be included. The order of steps listed in the embodiments is merely one possible execution order among many steps and does not represent the only execution order. In practice, when the method program is executed, it can be executed in the order shown in the embodiments or drawings or in parallel (e.g., in a parallel processor or multi-threaded processing environment). This method can be executed by a battery management system (BMS) or by a microcontroller (MCU) or industrial controller (such as a PLC, embedded board, etc.). This application embodiment does not limit this; the following embodiments use the battery pack dynamic balancing method executed by a battery management system as an example for illustrative purposes.

[0034] like Figure 1 As shown, the battery pack dynamic balancing method includes at least the following steps: S101: Calculate the target equalization threshold based on the preset initial equalization threshold and the real-time collected battery health status.

[0035] S103: When the voltage difference between any two individual cells exceeds the target equalization threshold, at least one of the two individual cells is identified as the cell to be equalized.

[0036] S105: Perform a balancing operation on at least one battery to be balanced in order to reduce the voltage difference between individual cells in the battery pack.

[0037] Specifically, firstly, an "initial equalization threshold" (e.g., 20mV or 30mV) needs to be set, which can be based on experience or manufacturer recommendations. The system will collect the health status (e.g., SOH) of each individual cell in real time and use it as a parameter in the calculation of the target equalization threshold.

[0038] For example, the following calculation formula can be designed: Target equilibrium threshold = Initial equilibrium threshold × [1 + k × (1 - SOH_min)] Where SOH_min represents the lowest health state among all individual cells, and k is the adjustment coefficient.

[0039] For example, suppose the initial equalization threshold is set to 30mV and the adjustment coefficient k is set to 1. When some batteries are detected to have a minimum SOH of 0.8, the target equalization threshold will be automatically calculated. 30mV × [1 + 1 × (1 - 0.8)] = 30mV × 1.2 = 36mV.

[0040] In this way, the system can dynamically calculate and adjust the target equalization threshold based on the actual health status of the battery, thereby avoiding damage to aging batteries caused by over-equalization and improving the overall equalization effect and safety.

[0041] When the Battery Management System (BMS) detects that the voltage difference between any two individual cells in the battery pack exceeds the "target balancing threshold" calculated based on the health status, the system marks at least one of these two cells (e.g., the one with the highest voltage) as a "cell to be balanced." In other words, the system will only initiate the balancing operation when the voltage difference exceeds the threshold, thus ensuring the consistency of the battery pack and avoiding unnecessary balancing.

[0042] Assume that the target equalization threshold has been calculated to be 36mV through the previous steps.

[0043] At a certain moment, the voltages of the four individual cells in the battery pack are as follows: Single cell A: 3.650V Single cell B: 3.630V Single cell C: 3.640V Single cell D: 3.685V At this point, the system will calculate the voltage difference between any two individual cells.

[0044] For example, the voltage difference between D and B is 3.685V - 3.630V = 0.055V = 55mV, which is greater than the target equalization threshold of 36mV.

[0045] Therefore, the system will mark the battery with the highest voltage, D (or the battery with the lowest voltage, B), as the "battery to be balanced" and prepare it for balancing.

[0046] This allows for more consistent voltage across the individual cells in the battery pack, improving overall performance and safety.

[0047] Next, balancing operations can be performed on the individual cells that have been identified as "cells to be balanced". These balancing operations typically include active balancing (such as charge transfer) or passive balancing (such as bypass resistor discharge). Through balancing operations, the voltage of these individual cells can gradually approach that of other cells, thereby reducing the voltage difference between individual cells in the entire battery pack and improving the consistency and lifespan of the battery pack.

[0048] Continuing with the previous example, suppose the system has already identified the cell with the highest voltage, D (3.685V), as the cell to be balanced.

[0049] Examples of equilibrium methods: Passive balancing: The system bypasses a resistor in battery D through a control circuit, causing D to discharge at a controlled rate and the voltage to decrease.

[0050] Active balancing: The system uses an energy transfer module to transfer some of the charge from battery D to batteries with lower voltages, such as B and C.

[0051] After a period of equalization, the voltage of battery D may drop to 3.655V, while the voltages of other batteries may not change significantly. At this point: Battery A: 3.650V Battery B: 3.630V Battery C: 3.640V Battery D: 3.655V The maximum voltage difference becomes 3.655V - 3.630V = 0.025V = 25mV, which is lower than the target equalization threshold of 36mV, thus achieving the equalization objective.

[0052] In some embodiments, reference Figure 2 , Figure 2 This is the second flowchart of the battery pack dynamic balancing method provided in the embodiments of this application. Figure 2 As shown, the method also includes the following three steps: S201: Determine the first coefficient based on the real-time collected battery health status.

[0053] S203: Determine the second coefficient based on the real-time collected ambient temperature.

[0054] S205: Calculate the target equilibrium threshold based on the preset initial equilibrium threshold, the first coefficient, and the second coefficient.

[0055] It is important to note that because ambient temperature significantly impacts battery performance and safe operation, it is crucial to consider ambient temperature as a critical factor in calculating the target equalization threshold, in addition to the battery's health status. Battery parameters such as chemical reaction rate, internal resistance, and equalization efficiency change under varying temperatures. For example, at low temperatures, battery activity decreases and internal resistance increases; using the equalization threshold set at room temperature may result in suboptimal equalization performance and even increase safety risks. Conversely, at high temperatures, an inappropriate equalization threshold may induce over-equalization of cells, affecting battery life. Therefore, incorporating ambient temperature into the calculation of the target equalization threshold helps to dynamically adjust the equalization strategy, improving the adaptability and safety of the battery management system.

[0056] Specifically, the system can first set an initial balancing threshold as the basic parameter for balancing control. Then, a first coefficient is determined based on the real-time acquired battery health status to reflect the impact of battery health status on balancing requirements. Simultaneously, a second coefficient can be determined based on the real-time monitored ambient temperature to reflect the impact of temperature on the balancing strategy. Finally, the target balancing threshold can be obtained as follows: Target balancing threshold = Initial balancing threshold × First coefficient × Second coefficient. Through this dynamic adjustment method, the system can effectively adapt to battery characteristics under different operating conditions, thereby achieving more precise balancing control and ensuring the stable operation and lifespan of the battery system.

[0057] In some embodiments, the target equilibrium threshold can be calculated based on the following formula: ; Among them, V t V0 is the target equalization threshold; V0 is the preset initial equalization threshold (which can be set according to battery characteristics and system design); d represents the degree of degradation of battery health status, with a value range of 0~100%. When the battery is in the new battery stage, d is 0; T is the real-time collected ambient temperature; T0 is the preset reference temperature value (such as room temperature 25℃); m is the first parameter, used to adjust the degree of influence of battery health status on the equalization threshold, which can be obtained through fitting a large amount of experimental data and engineering debugging and optimization; n is the second parameter, used to adjust the degree of influence of ambient temperature on the equalization threshold, which can be obtained through fitting a large amount of experimental data and engineering debugging and optimization; k is the scaling factor, which represents the sensitivity of the target equalization threshold to temperature changes. When k=10, it means that for every 10℃ change in temperature, the target equalization threshold only changes by 1 unit, which is used to prevent the temperature change from having too large an impact on the target equalization threshold, thereby improving the stability and robustness of the system.

[0058] The above calculation method can comprehensively consider factors such as battery health status and ambient temperature, and achieve dynamic adjustment of the target equilibrium threshold, thereby improving the adaptability and safety of the battery management system.

[0059] In some embodiments, such as Figure 2 As shown, the method also includes the following two steps: S207: When the voltage difference between any two individual cells is detected to exceed the target equalization threshold, obtain the duration for which the voltage difference exceeds the target equalization threshold.

[0060] S209: When the duration reaches the preset duration, at least one of the two individual cells is identified as the cell to be balanced.

[0061] Specifically, the system continuously monitors the voltage difference between individual cells and compares it to a preset target equalization threshold. When the voltage difference between any two individual cells exceeds the target equalization threshold, it does not immediately determine that equalization is required. Instead, it further acquires the duration of this voltage difference exceeding the threshold. Only when the voltage difference exceeds the target equalization threshold for a period of time or longer will the system identify the relevant individual cell as a cell to be equalized. This effectively avoids misjudgments caused by transient interference or short-term fluctuations, thereby improving the accuracy of equalization decisions and the stability of system operation.

[0062] For example, suppose a battery pack consists of 6 individual cells, with a target equalization threshold set at 0.05V and a duration threshold of 1 minute. When the system detects a voltage difference of 0.06V between battery 1 and battery 2 (exceeding the 0.05V threshold), it starts timing. If this voltage difference only lasts for 10 seconds and quickly returns below the threshold, it means that the voltage anomaly may only be due to temporary factors such as transient interference, short-term load fluctuations, temperature changes, or measurement errors, and does not necessarily reflect the actual imbalance state of the batteries. The system will not identify these two batteries as batteries to be equalized. Only when the voltage difference exceeds 0.05V for 1 minute or more will the system identify battery 1 and / or battery 2 as batteries to be equalized and initiate the corresponding equalization operation.

[0063] In some embodiments, the method for determining the batteries to be balanced may include selecting the battery with the highest voltage and reducing its voltage by discharging or limiting its charging, or selecting the battery with the lowest voltage and increasing its voltage by supplementing charging, thereby bringing the voltages of all batteries closer together. The specific method chosen may depend on the actual balancing strategy and circuit design.

[0064] In some embodiments, such as Figure 2 As shown, the method further includes step S211: when the voltage difference between two individual cells is updated to be less than or equal to the target equalization threshold, the equalization operation is stopped.

[0065] Specifically, to avoid over-balancing or resource waste during the battery balancing process, when the voltage difference between two individual cells is detected to be less than or equal to the target balancing threshold, it indicates that their voltages are close enough, and the balancing operation on the relevant cells will be stopped to ensure the efficiency of the balancing process and the safety of the batteries.

[0066] In some embodiments, parameters such as the number of charge-discharge cycles, capacity, and internal resistance of individual battery cells can be monitored in real time. Analysis of these parameters allows for the assessment of the state of health (SOH) of the individual battery cells. This reflects the actual use and performance degradation of the battery, enabling a dynamic and accurate assessment of its health.

[0067] For example, a single battery cell in a new energy vehicle has a factory capacity of 60Ah. After 100 cycles, its current capacity is 58.8Ah, and its internal resistance only increases slightly from 2.0mΩ to 2.05mΩ.

[0068] State of Harmony (SOH) is usually expressed as the ratio of the battery's current actual capacity to its factory rated capacity. The calculation formula is as follows: SOH = (Current Capacity / Initial Capacity) × 100% Take the data in the example as an example: Initial capacity (factory capacity): 60Ah Current capacity (measured after cycling): 58.8 Ah Substitute into the formula: SOH = (58.8 / 60) × 100% = 0.98 × 100% = 98% The SOH (State of Health) of 98% indicates that after a certain period of use, the battery's current capacity has only decreased by 2% compared to its original factory capacity, showing almost no degradation and indicating that the battery is in good health.

[0069] In some embodiments, the battery health status can be effectively obtained by analyzing the capacity and internal resistance parameters of individual battery cells. Specifically, this includes determining the capacity degradation rate based on the battery's rated capacity and current available capacity, and calculating the internal resistance growth rate by comparing the battery's initial internal resistance and current internal resistance. Subsequently, these two key indicators are combined with preset weighting coefficients for comprehensive calculation to assess the overall health status of the battery.

[0070] For example, if a single battery cell has a rated capacity of 100 Ah, and its current usable capacity drops to 90 Ah, then the capacity degradation rate is 10%. Meanwhile, if the initial internal resistance is 0.1 Ω, and the current internal resistance increases to 0.15 Ω, then the internal resistance growth rate is 50%. By combining these indicators with weighting coefficients, a comprehensive health status score can be obtained, helping to determine the battery's lifespan and performance degradation.

[0071] Based on the same technical concept, embodiments of this application also provide a battery pack dynamic balancing device, see reference. Figure 3 , Figure 3 This is one of the structural schematic diagrams of the battery pack dynamic balancing device provided in the embodiments of this application. For example... Figure 3 As shown, the device includes a calculation module 301, a judgment module 302, and an equalization module 303, wherein: The calculation module 301 is used to dynamically calculate and output a target equalization threshold suitable for the current battery state, based on the preset initial equalization threshold in the system and combined with the real-time health status parameters (such as SOH, internal resistance, temperature, etc.) collected by the battery pack. This target threshold can effectively guide subsequent equalization control strategies, realize adaptive equalization management of the battery pack, and improve the safety, equalization efficiency, and service life of the battery pack.

[0072] The judgment module 302 is used to monitor and compare the voltage of each individual cell in the battery pack in real time. When the voltage difference between any two individual cells exceeds the target equalization threshold, at least one of the two individual cells is identified as a cell to be equalized. In this way, the individual cells in the battery pack that need equalization can be identified in a timely manner, and a basis can be provided for subsequent equalization control, thereby improving the consistency and operational safety of the battery pack.

[0073] The balancing module 303 performs a balancing operation on at least one identified battery cell to be balanced, thereby reducing the voltage difference between individual cells in the battery pack. This effectively improves the consistency within the battery pack and extends its lifespan.

[0074] The physical entity of the battery pack dynamic balancing device can be a standalone balancing control circuit board, integrated into the battery management system (BMS), or embedded as an embedded intelligent module into the battery pack. Furthermore, the device can also be implemented as a portable maintenance device or a smart terminal with wireless communication capabilities, allowing for flexible deployment in different types of battery systems according to actual application needs.

[0075] Based on the same technical concept, embodiments of this application also provide a battery pack dynamic balancing device, see reference. Figure 4 , Figure 4 This is a second schematic diagram of the battery pack dynamic balancing device provided in the embodiments of this application. Figure 4 As shown, the device includes a memory 401 and a processor 402. The memory 401 is used to store computer instructions; when the processor 402 executes the computer instructions, it implements the method steps in any method embodiment.

[0076] The memory 401 includes at least one type of computer-readable storage medium, including flash memory, hard disk, solid-state drive (SSD), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), disk, etc. In some embodiments, the computer-readable storage medium may be an internal storage unit of an electronic device, such as the hard disk or memory of the electronic device. In other embodiments, the computer-readable storage medium may also be an external storage device of the electronic device, such as a plug-in hard disk, secure digital card (SD card), flash memory card, etc., equipped on the electronic device. Of course, the computer-readable storage medium may also include both internal storage units and external storage devices of the electronic device. In this embodiment, the computer-readable storage medium is typically used to store the operating system and various application software installed on the electronic device, such as the program code of the battery pack dynamic balancing method in the embodiment. In addition, the computer-readable storage medium may also be used to temporarily store various types of data that have been output or will be output.

[0077] In some embodiments, processor 402 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other chip. Processor 402 is typically used to control the overall operation of the processing device, such as performing control and processing related to data interaction or communication with other entities. In this embodiment, processor 402 is used to run program code stored in memory 401 or process data.

[0078] Based on the same technical concept, this application also provides a computer-readable storage medium, which includes a computer program or instructions stored in the storage medium. When the computer program or instructions are executed by a processing device, they implement the method steps in any method embodiment. Further details can be found in the method embodiments, which will not be repeated here. In this embodiment, the computer-readable storage medium includes flash memory, hard disk, solid-state drive (SSD), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), disk, etc. In some embodiments, the computer-readable storage medium can be an internal storage unit of an electronic device, such as the hard disk or memory of the electronic device. In other embodiments, the computer-readable storage medium can also be an external storage device of the electronic device, such as a plug-in hard disk, secure digital card (SD card), flash memory card, etc., equipped on the electronic device. Of course, the computer-readable storage medium can also include both internal storage units and external storage devices of the electronic device. In this embodiment, the computer-readable storage medium is typically used to store the operating system and various application software installed on the electronic device, such as the program code of the battery pack dynamic balancing method in the embodiment. Furthermore, the computer-readable storage medium can also be used to temporarily store various types of data that have been output or will be output.

[0079] Based on the same technical concept, embodiments of this application also provide a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the battery pack dynamic balancing method provided in the above-described method embodiments.

[0080] The above description involves various modules and units. It should be noted that the division of these modules and units in the description is for clarity. However, in actual implementation, the boundaries between various modules and units may be blurred. For example, any or all functional modules and units in this application may share various hardware and / or software elements. As another example, any and / or all functional modules in this application may be wholly or partially implemented by a shared processor executing software instructions. Furthermore, various software sub-modules executed by one or more processors may be shared among various software modules. Accordingly, unless expressly required, the scope of this application is not limited by mandatory boundaries between various hardware and / or software elements.

[0081] It should be noted that the order of description of the embodiments in this application is not intended to limit the priority of the embodiments.

[0082] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0083] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many forms under the guidance of this application without departing from the spirit and scope of protection of the claims. All equivalent transformations made under the inventive concept of this application using the content of this application's specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for dynamic balancing of a battery pack, characterized in that, Applied to a battery pack, the battery pack comprising multiple individual cells, the method includes: The target equalization threshold is calculated based on the preset initial equalization threshold and the real-time battery health status. When the voltage difference between any two individual cells exceeds the target equalization threshold, at least one of the two individual cells is determined to be a cell to be equalized. An balancing operation is performed on the at least one battery to be balanced in order to reduce the voltage difference between individual cells in the battery pack.

2. The battery pack dynamic balancing method according to claim 1, characterized in that, The step of calculating the target equalization threshold based on a pre-set initial equalization threshold and real-time collected battery health status includes: The first coefficient is determined based on the real-time collected battery health status. The second coefficient is determined based on the real-time collected ambient temperature. The target equilibrium threshold is calculated based on the preset initial equilibrium threshold, the first coefficient, and the second coefficient.

3. The battery pack dynamic balancing method according to claim 1 or 2, characterized in that, The calculation of the target equilibrium threshold includes: calculating the target equilibrium threshold based on the following formula: ; Among them, V t V0 is the target equalization threshold, V0 is the preset initial equalization threshold, d represents the degree of degradation of battery health status, and the value range is 0~100%. When the battery is in the new battery stage, d is 0, T is the real-time collected ambient temperature, T0 is the reference temperature value, m is the first parameter, n is the second parameter, and k is the scaling factor.

4. The battery pack dynamic balancing method according to any one of claims 1-3, characterized in that, The step of determining at least one of the two individual cells as the cell to be balanced when the voltage difference between any two individual cells exceeds the target balancing threshold includes: When the voltage difference between any two individual cells is detected to exceed the target equalization threshold, the duration for which the voltage difference exceeds the target equalization threshold is obtained; When the duration reaches a preset duration, at least one of the two individual cells is determined to be the cell to be balanced.

5. The battery pack dynamic balancing method according to claim 4, characterized in that, The step of determining at least one of the two individual cells as the cell to be balanced includes: The cell with the highest voltage among the two individual cells is identified as the cell to be balanced. And / or, determine the cell with the lowest voltage among the two individual cells as the cell to be balanced.

6. The battery pack dynamic balancing method according to any one of claims 1-5, characterized in that, The method further includes: The equalization operation is stopped when the voltage difference between the two individual cells is updated to be less than or equal to the target equalization threshold.

7. The battery pack dynamic balancing method according to any one of claims 1-6, characterized in that, The method further includes: Real-time monitoring of at least one parameter among charge-discharge cycle number, capacity, and internal resistance of a single battery cell; The battery health status of the individual battery is obtained based on at least one of the parameters.

8. The battery pack dynamic balancing method according to claim 7, characterized in that, The step of obtaining the battery health status of the individual battery cell based on the at least one parameter includes: Obtaining the battery health status of the individual cell based on the capacity and the internal resistance includes: The capacity decay rate is determined based on the rated capacity and available capacity of a single cell; The internal resistance growth rate is determined based on the initial internal resistance and current internal resistance of the individual cell. The battery health status of the individual cell is calculated based on the capacity decay rate, the internal resistance growth rate, and a preset weighting coefficient.

9. A battery pack dynamic balancing device, characterized in that, It includes a memory and a processor, the memory being used to store computer programs or instructions; when the computer programs or instructions are executed by the processor, the method of any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a processor, implement the method of any one of claims 1 to 8.

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