Balancing control method of battery pack, electronic device, and storage medium

Abstract

This application provides a battery pack balancing control method, electronic device, and storage medium, belonging to the field of battery balancing technology. The method includes: obtaining several correction intervals and several non-correction intervals based on the open-circuit voltage curve of the battery pack to be balanced; matching the voltage of the smallest individual cell in the battery pack with the several correction intervals and several non-correction intervals to determine the open-circuit voltage interval corresponding to the smallest individual cell; correcting the state of charge (SOC) of the first individual cell whose voltage is in the non-correction interval according to the open-circuit voltage interval and a first correction algorithm; correcting the SOC of the second individual cell whose voltage is in the correction interval according to a preset second correction algorithm; and performing balancing processing on the battery pack based on the SOC of each third individual cell. This application embodiment can improve the consistency of each cell in the battery pack.

Description

Technical Field

[0001] This application relates to the field of battery balancing technology, and in particular to a battery pack balancing control method, electronic device, and storage medium. Background Technology

[0002] When batteries are used in electric vehicles, energy storage systems, and other fields, they must be connected in series and parallel to form battery packs to increase the total voltage and capacity due to the limitations of the voltage and capacity of individual cells. In this process, inconsistencies inevitably arise between the individual cells within the battery pack. While related technologies employ capacity balancing methods for battery equalization, for battery packs with relatively flat operating voltage platforms (especially lithium iron phosphate batteries), the estimation of capacity differences between cells is not accurate enough. Therefore, the effectiveness of capacity balancing in achieving equalization is poor, resulting in poor consistency among the cells within the battery pack. Summary of the Invention

[0003] The main objective of this application is to propose a battery pack equalization control method, electronic device, and storage medium, which aims to improve the consistency of each cell in the battery pack.

[0004] To achieve the above objectives, a first aspect of this application provides a battery pack equalization control method, the method comprising:

[0005] Based on the open-circuit voltage curve of the battery pack to be balanced, several correction intervals and several non-correction intervals are obtained.

[0006] The voltage of the smallest cell in the battery pack is matched with several corrected intervals and several uncorrected intervals to determine the open-circuit voltage interval corresponding to the smallest cell.

[0007] Based on the open-circuit voltage range and the first correction algorithm, the state of charge of the first cell in the battery pack whose individual cell voltage is located in the non-correction range is corrected.

[0008] According to the preset second correction algorithm, the state of charge of the second cell in the battery pack whose individual cell voltage is in the correction range is corrected;

[0009] After correcting the first and second battery cells, the battery pack is balanced according to the state of charge of each third battery cell.

[0010] To achieve the above objectives, a second aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect.

[0011] To achieve the above objectives, a third aspect of the present application provides a storage medium, which is a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0012] The battery pack equalization control method, electronic device, and storage medium proposed in this application determine whether each third cell in the battery pack falls within the correction or non-correction range of the open-circuit voltage curve before equalization processing, based on the open-circuit voltage curve of the battery pack to be equalized. Then, based on the open-circuit voltage range corresponding to the smallest cell in the battery pack, the first cell in the non-correction range is corrected for its state of charge (SOC) using a first correction algorithm, and the second cell in the correction range is corrected for its SOC using a second correction algorithm. This allows for the selection of different correction algorithms based on characteristic ranges. Consequently, the capacity estimation of each third cell in the battery pack based on the corrected SOC is more accurate, resulting in better capacity equalization control and improved cell consistency. Therefore, compared with existing technologies, the embodiments of this application can improve the consistency of each cell in the battery pack. Attached Figure Description

[0013] Figure 1 This is a schematic flowchart of the battery pack equalization control method provided in the embodiments of this application;

[0014] Figure 2 This is a schematic diagram of the open-circuit voltage curve in the battery pack equalization control method provided in the embodiments of this application;

[0015] Figure 3 This is a specific embodiment of the battery pack equalization control method provided in this application, which is the process for determining the charging end.

[0016] Figure 4 This is a flowchart illustrating the voltage balance determination process of a specific embodiment of the battery pack equalization control method provided in this application.

[0017] Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0021] When batteries are used in electric vehicles, energy storage systems, and other fields, due to the limitations of individual cell voltage and capacity, they must be connected in series and parallel to form battery packs to increase the total voltage and capacity. In this process, inconsistencies inevitably arise between the individual cells within the battery pack. While related technologies employ capacity balancing methods for battery equalization control, for battery packs with relatively flat operating voltage platforms (especially lithium iron phosphate batteries), the estimation of capacity differences between cells is not accurate enough. Therefore, the effect of achieving equalization through capacity balancing is poor, resulting in poor consistency among the cells in the battery pack. Based on this, embodiments of this application provide a battery pack equalization control method, electronic device, and storage medium, aiming to improve the consistency of the cells in the battery pack.

[0022] The battery pack equalization control method, electronic device, and storage medium provided in this application are specifically described through the following embodiments. First, the battery pack equalization control method in this application embodiment is described.

[0023] The battery pack balancing control method provided in this application relates to the field of battery balancing technology. This method can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, etc.; the server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms; the software can be an application implementing the battery pack balancing control method, but is not limited to the above forms.

[0024] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0025] Figure 1 This is an optional flowchart of the battery pack balancing control method provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S101 to S105.

[0026] Step S101: Based on the open-circuit voltage curve of the battery pack to be balanced, obtain several correction intervals and several non-correction intervals.

[0027] Reference Figure 2 As shown, taking a lithium iron phosphate (LFP) battery pack as an example, the open-circuit voltage curve is the OCV-SOC curve. Based on the rate of change of the OCV-SOC curve, three corrected intervals and two uncorrected intervals can be obtained. The three corrected intervals are S1, S3 and S5, and the two uncorrected intervals are S2 and S4.

[0028] It should be noted that the corrected range indicates that the open circuit voltage (OCV) of a single cell varies significantly with the state of charge (SOC) within this range, while the uncorrected range indicates that the OCV of a single cell varies less with the SOC within this range. Specifically, those skilled in the art can define the range based on the OCV-SOC curve, and this application does not impose any limitations on this.

[0029] Step S102: Match the voltage of the smallest cell in the battery pack with several corrected intervals and several uncorrected intervals to determine the open-circuit voltage interval corresponding to the smallest cell.

[0030] It should be noted that the open-circuit voltage range is one of several corrected ranges and several uncorrected ranges. "Several" indicates that there is at least one.

[0031] It should be noted that the smallest cell refers to the cell with the lowest voltage in the battery pack. For example, if the battery pack consists of cell 1, cell 2, and cell 3, and cell 2 has a lower voltage than cell 1 and cell 3, then cell 2 is the smallest cell.

[0032] It should be noted that the individual cell voltage corresponds to the OCV in the OCV-SOC curve.

[0033] Step S103: Based on the open-circuit voltage range and the first correction algorithm, correct the state of charge of the first cell in the battery pack whose individual cell voltage is in the non-correction range.

[0034] It should be noted that the first correction algorithm is based on the positional relationship between the first battery cell and the open-circuit voltage range, setting the individual cell voltage of all first battery cells within the non-correction range to a specific value within the non-correction range. If the first battery cell is located within the open-circuit voltage range, a value is selected from the right boundary data range of the open-circuit voltage range as the state of charge. The right boundary data includes the right boundary and the difference between the value and the right boundary is within a preset threshold. Specifically, the threshold corresponding to the right boundary can be defined according to actual needs in the art. Alternatively, if the first battery cell is located outside the open-circuit voltage range, a value is selected from the left boundary data of the non-correction range where it is located as the state of charge. The left boundary data includes the left boundary and the difference between the value and the left boundary is within a preset threshold. Specifically, the threshold corresponding to the left boundary can be defined according to actual needs in the art. This application does not impose limitations on this aspect.

[0035] Step S104: According to the preset second correction algorithm, the state of charge of the second cell in the battery pack whose individual cell voltage is in the correction range is corrected.

[0036] It should be noted that the second correction algorithm means that all second cell units located within the correction interval are corrected based on the mapping relationship of the OCV-SOV curves within the correction interval.

[0037] Step S105: After correcting the first and second battery cells, the battery pack is balanced according to the state of charge of each third battery cell in the battery pack.

[0038] It should be noted that the equalization process includes at least capacity equalization control, and in some embodiments, it also includes voltage equalization control. The battery pack is composed of individual third-generation cells.

[0039] Therefore, before equalization, by first determining whether each third cell in the battery pack falls within the correction or non-correction range of the open-circuit voltage curve based on the open-circuit voltage curve of the battery pack to be equalized, and then, based on the open-circuit voltage range corresponding to the smallest cell in the battery pack, the first cell in the non-correction range is corrected for its state of charge (SOC) using a first correction algorithm, and the second cell in the correction range is corrected for its SOC using a second correction algorithm. This achieves the selection of different correction algorithms for correction based on characteristic ranges. At this point, the capacity estimation of each third cell in the battery pack based on the corrected SOC is more accurate, resulting in better capacity equalization control and improved consistency among the cells. Therefore, compared with the prior art, the embodiments of this application can improve the consistency of the cells in the battery pack.

[0040] Understandably, step S103, which corrects the state of charge of the first cell whose voltage is in the non-correction range in the battery pack according to the open-circuit voltage range and the first correction algorithm, includes: when the open-circuit voltage range is the same as the non-correction range in which the first cell is located, the first boundary value of the non-correction range is used as the state of charge of the corresponding first cell; when the open-circuit voltage range is different from the non-correction range in which the first cell is located, the second boundary value of the non-correction range is used as the state of charge of the corresponding first cell.

[0041] It should be noted that the first boundary value and the second boundary value correspond to the two boundaries of the uncorrected interval, respectively. In some embodiments, the first boundary value is the left boundary value of the uncorrected interval, and the second boundary value is the right boundary value of the uncorrected interval. In other embodiments, the first boundary value is the right boundary value of the uncorrected interval, and the second boundary value is the left boundary value of the uncorrected interval. This application does not impose any restrictions on this.

[0042] For example, refer to Figure 2 As shown, taking S2 of the open-circuit voltage range corresponding to OCV-SOC as an example, when the voltage of the first cell is also located in S2, the SOC value of the first cell is the right boundary value of S2, i.e., 60% SOC. When the voltage of the first cell is located in S4, the SOC of the first cell is corrected to the left boundary value of S4, i.e., 65% SOC. For example, taking... Figure 2 Taking S1 of the open-circuit voltage range corresponding to OCV-SOC as an example, the SOC of the first cell is corrected to the left boundary value of the corresponding uncorrected range. For example, the SOC of the first cell in the S2 range is 30% SOC, and the SOC of the first cell in the S4 range is 65% SOC.

[0043] Understandably, step S104, according to the preset second correction algorithm, corrects the state of charge of the second cell whose single cell voltage is in the correction range in the battery pack, including: determining the state of charge of the second cell according to the mapping relationship of the open circuit voltage curve in the correction range corresponding to the second cell.

[0044] It should be noted that the mapping relationship represents the functional relationship between OCV and SOC. By inputting the individual cell voltage of the second cell into the mapping relationship as the dependent variable, the corresponding independent variable value can be obtained, thus determining the state of charge of the second cell.

[0045] Understandably, step S105 involves balancing the battery pack based on the state of charge of each third cell, including: recalculating the current capacity balancing data of the third cell; determining whether to perform capacity balancing control on the corresponding third cell based on the capacity balancing data of each third cell in the battery pack; updating the corresponding capacity balancing data based on the result of the capacity balancing control; and determining whether to perform voltage balancing calculation based on the capacity balancing data of each third cell in the battery pack.

[0046] It should be noted that the capacity balancing data serves as the basis for capacity balancing control of the corresponding third-cell unit, and includes at least the time used for capacity balancing control. Multiple third-cell units constitute a battery pack.

[0047] Understandably, recalculating the current capacity balancing data of the third cell includes: obtaining the maximum full-charge capacity of the third cell; calculating the remaining capacity based on the maximum full-charge capacity and the state of charge of the third cell; calculating the reference capacity difference based on the remaining capacity of each third cell in the battery pack; and calculating the capacity balancing time based on the reference capacity difference, the remaining capacity, and the preset balancing current. The capacity balancing time is one of the capacity balancing data.

[0048] It should be noted that the reference capacity difference is the condition for determining whether to calculate the capacity equalization time. In some embodiments, when the reference capacity difference is greater than a preset capacity threshold, such as 2% of the maximum full charge capacity, the capacity equalization time will be calculated based on the remaining capacity and the preset equalization current.

[0049] For example, with the maximum full charge capacity as Q Full For example, the remaining capacity Q Res (i)=SOC(i)*Q Full Where i represents the number of the third cell, and SOC(i) is the state of charge of the third cell numbered i. Reference capacity difference ΔQ(i) = Q Res (i)-Q min ; where Q minThis represents the minimum remaining capacity among all the third-generation cells in the battery pack. At this point, a threshold value for capacity balancing can be obtained, let's assume it's set to Q. Full If 2%, then when ΔQ(i) > Q Full If the value is ×2%, then the i-th third cell corresponding to the battery pack needs to be equalized. At this time, the capacity equalization time T Bal (i)=Q Res (i)÷I Bal , among which, I Bal To balance the current.

[0050] Understandably, the method also includes: when the reference capacity difference is greater than the preset capacity threshold, setting the capacity balancing flag corresponding to the third cell to enable capacity balancing control; the capacity balancing flag is one of the capacity balancing data; before the battery goes into hibernation, saving the capacity balancing flag and capacity balancing time of the third cell at the current moment to the preset non-volatile memory.

[0051] It should be noted that the value of the capacity balancing flag indicates whether capacity balancing control needs to be enabled. For example, a value of 1 indicates that capacity balancing control needs to be enabled. The capacity balancing flag and capacity balancing time are saved to a preset non-volatile memory. If the battery management system (BMS) has not corrected this upon the next wake-up, it can directly use the capacity balancing flag and balancing time stored in the non-volatile memory (NVM) as the capacity balancing data for the corresponding third cell for balancing processing.

[0052] Understandably, based on the capacity balancing data of each third cell in the battery pack, it is determined whether to perform voltage balancing calculation, including: determining the capacity balancing time of the corresponding third cell based on the capacity balancing data; when each capacity balancing time meets the preset conditions, determining whether each third cell is at the end of charging; and performing voltage balancing calculation on the third cells at the end of charging.

[0053] It should be noted that the preset condition can be set to a capacity balancing time of 0. In this case, when the capacity balancing time of all third-cell units is 0, it indicates that the battery pack has completed the capacity balancing calculation, and it can be determined that voltage balancing calculation will be performed. Before performing voltage calculation, it is preferable to use the third-cell unit at the end of the charging process as the object of voltage balancing calculation.

[0054] It should be noted that the condition for determining the end of the battery is as follows: when the battery pack is in a charging state and the state of charge of the third cell to be determined is greater than a preset third threshold, the condition for determining whether the third cell to be determined is at the end of the charging process is determined based on the charging current and charging time of the third cell to be determined.

[0055] It should be noted that the third threshold is the starting point of the SOC charging end, and can be adjusted according to the actual situation of the battery cell and the project. Therefore, this application embodiment does not limit the specific value of the third threshold.

[0056] It should be noted that the charging current is the pack current; both the charging current and charging duration can be adjusted according to the actual situation of the battery cell and the project. The charging duration represents the duration during which the current is less than the charging terminal current threshold. The charging duration is to prevent misjudgment caused by sudden current changes, and this value can be adjusted. For example, assuming the charging terminal current threshold is defined as 0.33C, taking a battery cell capacity of 100AH ​​as an example, the terminal current threshold is 100 * 0.33 = 33A.

[0057] For example, refer to Figure 3 As shown, taking a third battery cell as an example, when the third battery cell is in a charging state and its SOC > 95%, where 95% is the third threshold; then it is determined whether the current is less than the charging end current threshold of 10A. If not, it is determined whether the continuous charging time is greater than a preset first time of 3 seconds. If it is greater, ChgTailEndFlag = 0 (i.e., the charging end identifier is 0); if it is less than the preset first time of 3 seconds, it is re-determined whether the charging current is less than the charging end current threshold of 10A. If it is, it is determined whether the continuous charging time is greater than a preset second time of 20 seconds. If the continuous charging time is greater than the preset second time of 20 seconds, ChgTailEndFlag = 1 (i.e., the charging end identifier is 1). This cyclic detection method ensures that the charging end identifier of each third battery cell is accurate, and thus, it is possible to determine whether each third battery cell is the charging end based on the charging end identifier. By setting the charging end identifier, the determination and the actual voltage equalization processing are separated. In some embodiments, it is also possible not to set the charging end identifier, and this application embodiment does not limit this.

[0058] Understandably, the voltage balancing calculation for the third battery cell at the end of the charging process includes: comparing the voltage of the third battery cell with a first threshold; turning off the voltage balancing control of the third battery cell when the voltage of the third battery cell is less than the first threshold; and comparing the difference between the voltage of the third battery cell and the voltage of the smallest battery cell when the voltage of the third battery cell is greater than or equal to the first threshold with a second threshold, and determining whether to turn on or off the voltage balancing control of the third battery cell based on the comparison result.

[0059] It should be noted that the first threshold is the terminal voltage threshold, which can be set according to the actual situation.

[0060] For example, refer to Figure 4 As shown, for each third cell's voltage, voltage equalization is disabled when the cell voltage is less than the end voltage threshold. When the cell voltage is greater than or equal to the end voltage threshold, it is determined whether the difference between the third cell's voltage and the lowest cell's voltage is greater than a second threshold (i.e., the equalization voltage difference threshold). If it is greater than the equalization voltage difference threshold, voltage equalization is enabled; otherwise, it is disabled. Then, it is determined whether there is another undetected third cell until all third cells in the battery pack have been detected. The equalization voltage difference threshold can be set according to actual conditions.

[0061] It should be noted that the specific voltage balancing process is existing technology, and this application will not elaborate on it further.

[0062] Understandably, before the state of charge of the first and second battery cells is corrected, historical capacity balancing data of each third battery cell in the battery pack is obtained from a preset location; and the battery pack is balanced based on the historical capacity balancing data.

[0063] It should be noted that the preset location can be the aforementioned non-volatile memory, and the preset location is used to store the capacity balancing data before power loss. At this time, for each third cell in the battery pack, when the SOC correction is not triggered, the capacity balancing data is obtained from the preset location for capacity balancing control; when the correction is triggered, the capacity balancing data is recalculated for capacity balancing control.

[0064] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described battery pack equalization control method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0065] Please see Figure 5 , Figure 5 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes:

[0066] The processor 201 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0067] The memory 202 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 202 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 202 and is called and executed by the processor 201 to execute the battery pack balancing control method of the embodiments of this application.

[0068] Input / output interface 203 is used to implement information input and output;

[0069] The communication interface 204 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0070] Bus 205 transmits information between various components of the device (e.g., processor 201, memory 202, input / output interface 203, and communication interface 204);

[0071] The processor 201, memory 202, input / output interface 203 and communication interface 204 are connected to each other within the device via bus 205.

[0072] This application embodiment also provides a storage medium, which is a computer-readable storage medium, storing a computer program that, when executed by a processor, implements the above-described battery pack equalization control method.

[0073] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0074] The battery pack equalization control method, electronic device, and storage medium provided in this application, before performing equalization processing, first determine whether each third cell in the battery pack is in the correction range or the non-correction range of the open-circuit voltage curve of the battery pack to be equalized. Then, based on the open-circuit voltage range corresponding to the smallest cell in the battery pack, the first cell in the non-correction range is corrected for its state of charge (SOC) according to a first correction algorithm, and the second cell in the correction range is corrected for its SOC according to a second correction algorithm. This achieves the selection of different correction algorithms for correction based on characteristic ranges. At this time, the capacity estimation of each third cell in the battery pack based on the corrected SOC is more accurate, thereby improving the capacity equalization control effect and enhancing the consistency of each cell. Therefore, compared with the prior art, the embodiments of this application can improve the consistency of each cell in the battery pack.

[0075] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0076] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0077] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0078] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0079] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0080] The technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0081] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method of equalization control of a battery pack, characterized by, include: Based on the open-circuit voltage curve of the battery pack to be balanced, several correction intervals and several non-correction intervals are obtained. The voltage of the smallest cell in the battery pack is matched with several corrected intervals and several uncorrected intervals to determine the open-circuit voltage interval corresponding to the smallest cell. Based on the open-circuit voltage range and the first correction algorithm, the state of charge of the first cell in the battery pack whose individual cell voltage is located in the non-correction range is corrected. According to the preset second correction algorithm, the state of charge of the second cell in the battery pack whose individual cell voltage is in the correction range is corrected; After correcting the first and second battery cells, the battery pack is balanced according to the state of charge of each third battery cell in the battery pack. The step of correcting the state of charge of a first cell in the battery pack whose voltage is in the non-correction range based on the open-circuit voltage range and the first correction algorithm includes: When the open-circuit voltage range is the same as the uncorrected range where the first cell is located, the first boundary value of the uncorrected range is taken as the corresponding state of charge of the first cell. When the open-circuit voltage range is different from the uncorrected range where the first cell is located, the second boundary value of the uncorrected range is taken as the corresponding state of charge of the first cell.

2. The method of claim 1, wherein, The step of correcting the state of charge of the second cell in the battery pack whose individual cell voltage is within the correction range according to the preset second correction algorithm includes: The state of charge of the second cell is determined based on the mapping relationship of the open-circuit voltage curve in the correction interval corresponding to the second cell.

3. The method of claim 1, wherein, The step of balancing the battery pack according to the state of charge of each third cell includes: Recalculate the current capacity balancing data for the third battery cell; Based on the capacity balancing data of each third cell in the battery pack, determine whether to perform capacity balancing control on the corresponding third cell. Update the corresponding capacity balancing data based on the results of capacity balancing control; Based on the capacity balancing data of each third cell in the battery pack, determine whether to perform voltage balancing calculation.

4. The method of claim 3, wherein, The recalculation of the current capacity balancing data for the third battery cell includes: Obtain the maximum full-charge capacity of the third battery cell; Calculate the remaining capacity based on the maximum full charge capacity and the state of charge of the third battery cell; The reference capacity difference is calculated based on the remaining capacity of each third cell in the battery pack. The capacity balancing time is calculated based on the reference capacity difference, the remaining capacity, and the preset balancing current; wherein the capacity balancing time is one of the capacity balancing data.

5. The method of claim 3, wherein, The step of determining whether to perform voltage balancing calculation based on the capacity balancing data of each third cell in the battery pack includes: Based on the capacity balancing data, determine the capacity balancing time of the corresponding third cell. When all the capacity balancing times meet the preset conditions, it is determined whether each of the third battery cells is at the end of charging. Voltage balancing calculations are performed on the third battery cell at the end of the charging process.

6. The method of claim 5, wherein, The voltage equalization calculation for the third battery cell at the end of the charging process includes: The voltage of the third battery cell is compared with a first threshold. When the voltage of the third battery cell is less than the first threshold, the voltage equalization control of the third battery cell is turned off. When the voltage of the third battery cell is greater than or equal to the first threshold, the difference between the voltage of the third battery cell and the voltage of the smallest battery cell is compared with the second threshold, and the voltage equalization control of the third battery cell is turned on or off based on the comparison result.

7. The method of claim 1, wherein, The method further includes: Before triggering the correction of the state of charge of the first and second battery cells, historical capacity balancing data of each third battery cell in the battery pack is obtained from a preset location; and the battery pack is balanced according to the historical capacity balancing data.

8. An electronic device, comprising: The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the equalization control method for the battery pack according to any one of claims 1 to 7.

9. A computer readable storage medium, the storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by the processor, it implements the battery pack equalization control method according to any one of claims 1 to 7.

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