Charge equalization method, apparatus, electronic device, and readable storage medium

Abstract

The application discloses a charge equalization method and device, electronic equipment and a readable storage medium. The charge equalization method comprises the following steps: acquiring a first charge amount of each battery cell in a plurality of battery cells of a battery pack, wherein the battery pack comprises parallel branches, each branch comprises at least one battery cell, and the first charge amount is the charge amount of the battery cell charged within a charging time; and determining a target equalization charge amount of each battery cell according to the first charge amount of each battery cell in the battery pack and a target equalization voltage of each branch. According to the embodiment of the application, the accuracy of the estimated charge amount transferred between the battery cells can be improved when the battery stops charging.

Description

Technical Field

[0001] This application belongs to the field of batteries, and particularly relates to a charge balancing method, apparatus, electronic device, and readable storage medium. Background Technology

[0002] With the development of new energy sources, more and more fields are adopting new energy sources as power sources. Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, batteries are widely used in new energy vehicles, consumer electronics, energy storage systems, and other fields.

[0003] For batteries with multiple parallel branches, due to limitations in battery manufacturing processes or differences in the degree of use among individual battery cells, an imbalance can easily occur between the individual cells when charging stops. As a result, charge transfer will occur between the individual cells after charging stops. If the amount of charge transferred between the individual cells cannot be accurately estimated, it is difficult to accurately determine whether the individual cells are charging, which can easily lead to the risk of overcharging some individual cells in the battery. Summary of the Invention

[0004] This application provides a charge balancing method, apparatus, electronic device, and readable storage medium that can improve the accuracy of estimating the amount of charge transferred between individual battery cells when the battery stops charging.

[0005] In a first aspect, this application provides a charge balancing method, the method comprising:

[0006] The first charge amount of each battery cell in a battery pack is obtained, wherein the battery pack includes parallel branches, each branch includes at least one battery cell, and the first charge amount is the amount of charge charged into the battery cell during the charging time.

[0007] The target balanced charge of each battery cell is determined based on the first charge of each battery cell in the battery pack and the target balanced voltage of each branch.

[0008] In the technical solution of this application embodiment, the battery pack includes parallel branches, and each branch may include at least one battery cell. By obtaining the first charge amount of each battery cell in the battery pack during the charging time, the charge increase in each battery cell can be quickly determined. Next, based on the first charge amount of each battery cell in the battery pack and the target equalization voltage, the target equalization charge amount of each battery cell can be quickly determined. The target equalization charge amount can be used as the actual charge amount charged into each battery cell after charge transfer, improving the accuracy of estimating the actual charge amount charged into the battery cell.

[0009] In some embodiments, the method further includes:

[0010] Obtain the fourth charge amount of each battery cell at a preset time, which is the time before charging begins;

[0011] For each battery cell, the sum of the target balanced charge and the fourth charge is calculated to obtain the fifth charge of the battery cell.

[0012] When the fifth charge amount is greater than the preset charge amount, the detection result is obtained, which includes the overcharge risk information of the battery cell.

[0013] According to the embodiments of this application, after the battery pack finishes charging, the target equalization charge change of each battery cell can be calculated quickly and accurately, which facilitates the calculation of the actual charge of each battery cell after equalization in the entire parallel circuit, and accurately determines whether there is a safety risk of overcharging in the battery cell.

[0014] In some embodiments, the target equalization voltage is the open-circuit voltage of the branch where the battery cell is located, and the target equalization voltage satisfies a preset voltage equalization condition; determining the target equalization charge of each battery cell based on the first charge of each battery cell in the battery pack and the target equalization voltage of each branch includes:

[0015] Based on the first charge of each battery cell in the battery pack, determine the first average charge of each battery cell in each branch and the second average charge of each battery cell in the battery pack.

[0016] The target balanced charge of each battery cell in each branch is determined based on the first charge of each battery cell, the first average charge of each branch, the second average charge, and the target balanced voltage.

[0017] According to the embodiments of this application, the first average charge change of each battery cell in the battery pack and the second average charge change of each battery cell in the battery pack are determined by the first charge change of each battery cell in the battery pack. The first charge change of each battery cell is adjusted in combination with the target equalization voltage, thereby improving the accuracy of estimating the actual charge amount charged into the battery cell.

[0018] In some embodiments, determining the target balanced charge of each battery cell in each branch based on the first charge of each battery cell, the first average charge of each branch, the second average charge, and the target balanced voltage includes:

[0019] For each branch, when the first average charge is not equal to the second average charge, the second charge of each battery cell in the branch is determined by balancing calculation based on the first charge of each battery cell in the branch, the first average charge of the branch, and the second average charge.

[0020] Based on the second charge quantity of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell, the first open-circuit voltage of each branch is determined;

[0021] When the first open-circuit voltage of each branch meets the preset voltage equalization condition, the second charge of each battery cell in the branch is taken as the target equalization charge of each battery cell.

[0022] According to the embodiments of this application, by performing a balanced calculation on the first charge change of each battery cell in the battery pack, the second charge change of each battery cell in the battery pack is obtained. Combined with the open-circuit voltage of each branch and the preset voltage balance condition, it is determined whether the entire parallel circuit has reached a balanced state. This enables a rapid estimation of the actual charge amount charged into the battery cell and improves the accuracy of the estimated actual charge amount charged into the battery cell.

[0023] In some embodiments, the method further includes:

[0024] When the first open-circuit voltage of at least one branch does not meet the preset voltage equalization condition, the equalization calculation is continued based on the second charge of each battery cell in the branch, the first average charge of the branch, and the second average charge to determine the third charge of each battery cell in the branch.

[0025] The second open-circuit voltage of each branch is determined based on the third charge of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell.

[0026] When the second open-circuit voltage of each branch meets the preset voltage equalization condition, the third charge of each battery cell in the branch is taken as the target equalization charge of each battery cell.

[0027] When the second open-circuit voltage of at least one branch does not meet the preset voltage equalization condition, iterative equalization calculation is performed based on the third charge of each battery cell in the branch, the first average charge of the branch, and the second average charge, until the target equalization charge of each battery cell is obtained.

[0028] According to the embodiments of this application, after the charge change of each battery cell in the battery pack is adjusted once, it is immediately determined whether the open circuit voltage of each branch meets the preset voltage equalization condition, thereby enabling rapid estimation of the actual charge of the battery cell and improving the accuracy of the estimated actual charge of the battery cell.

[0029] In some embodiments, the second charge of each battery cell in a branch is determined by performing an equalization calculation based on the first charge of each battery cell in the branch, the first average charge of the branch, and the second average charge, including:

[0030] For each branch, calculate the absolute value of the first difference between the first average charge and the second average charge corresponding to the branch, and calculate the product of the absolute value of the first difference and the preset balance parameter to obtain the charge balance amount, wherein the preset parameter is greater than 0 and less than 1.

[0031] The second charge of each battery cell is determined based on the charge balance and the first charge of each battery cell in each branch.

[0032] According to the embodiments of this application, the charge balance of each battery cell is calculated, and combined with the first charge change of each battery cell in each branch, the second charge change of each battery cell is determined, thereby improving the accuracy of the estimated target charge balance change.

[0033] In some embodiments, determining a second charge amount for each battery cell based on the charge balance amount and a first charge amount for each battery cell in each branch includes:

[0034] For each branch, when the first average charge of the branch is greater than the second average charge, the difference between the first charge and the charge balance of each battery cell in the branch is calculated to obtain the second charge.

[0035] When the first average charge of a branch is less than the second average charge, the sum of the first charge and the charge balance of each battery cell in the branch is calculated to obtain the second charge.

[0036] According to the embodiments of this application, the charge balance of each battery cell is calculated, and combined with the first charge of each battery cell in each branch, the second charge of each battery cell is determined, thereby improving the accuracy of the estimated target balance charge.

[0037] In some embodiments, the preset voltage equalization conditions include:

[0038] The second difference between the first open-circuit voltage of each branch in the parallel branches and the average value of the open-circuit voltages of all branches is less than the first preset voltage.

[0039] or,

[0040] The third difference between the largest and smallest first open-circuit voltages in the parallel branches is less than the second preset voltage.

[0041] According to the preset voltage balancing conditions set in the embodiments of this application, by combining the magnitude relationship of the open circuit voltage between branches, it is determined whether the battery pack has reached a balanced state, thereby improving the calculation speed of the balanced charge.

[0042] Secondly, this application provides a charge equalization device, which includes:

[0043] The acquisition module is used to acquire the first charge of each battery cell in the multiple battery cells of the battery pack, wherein the battery pack includes parallel branches, each branch includes at least one battery cell, and the first charge is the amount of charge charged into the battery cell during the charging time.

[0044] The processing module is used to determine the target balanced charge of each battery cell based on the first charge of each battery cell in the battery pack and the target balanced voltage of each branch.

[0045] According to embodiments of this application, for a battery pack including parallel branches, and each branch including at least one battery cell, the amount of charge increase of each battery cell during the charging time can be quickly determined by acquiring the first charge change of each battery cell in the battery pack. Next, based on the first charge of each battery cell in the battery pack and the target equalization voltage, the target equalization charge of each battery cell can be quickly determined. The target equalization charge can then be used as the actual charge received by each battery cell after charge transfer, improving the accuracy of estimating the actual charge received by the battery cell.

[0046] Fourthly, this application provides an electronic device, the device comprising: a processor and a memory storing computer program instructions; the processor, when executing the computer program instructions, implements the charge balancing method of the first aspect or any embodiment of the first aspect.

[0047] Fifthly, this application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the method of the first aspect or any embodiment of the first aspect.

[0048] In a sixth aspect, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform a charge balancing method as described in the first aspect or any embodiment of the first aspect.

[0049] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0050] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0051] Figure 1 This is a schematic flowchart of a charge balancing method provided in an embodiment of this application;

[0052] Figure 2 This is a schematic flowchart of another charge balancing method provided in an embodiment of this application;

[0053] Figure 3 This is a schematic diagram of the structure of a charge equalization device provided in an embodiment of this application;

[0054] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0055] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0056] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0057] In the description of the embodiments of this application, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0058] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0059] With the development of new energy sources, more and more fields are adopting new energy sources as power sources. Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, batteries are widely used in new energy vehicles, consumer electronics, energy storage systems, and other fields.

[0060] For example, batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application areas of batteries continue to expand, the market demand is also constantly increasing.

[0061] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. Exemplarily, the battery can be a lithium-ion battery, lithium metal battery, lead-acid battery, nickel-metal hydride battery, lithium-sulfur battery, lithium-air battery, or sodium-ion battery, etc., and is not limited thereto. In terms of scale, the battery in the embodiments of this application can be a single battery cell, a battery module, or a battery pack, and is not limited thereto. In terms of application scenarios, the battery can be used in power devices such as automobiles and ships. For example, it can be used in electric vehicles to power the electric vehicle's motor, serving as the power source for the electric vehicle. The battery can also power other electrical components in the electric vehicle, such as the in-vehicle air conditioner and in-vehicle media player.

[0062] A battery pack can include individual battery cells connected in parallel or in series. For a battery with multiple parallel branches, the battery cells can be distributed across different branches. Due to limitations in battery manufacturing processes, or due to differences in the degree of use among the battery cells, an imbalance can easily occur among the battery cells when charging stops. Therefore, charge transfer will occur between the battery cells after charging stops.

[0063] For example, battery parameters such as capacity, temperature, internal chemical characteristics, and internal resistance may differ when charging individual battery cells in different usage stages. When charging stops, the total charge in different branches may vary, causing charge transfer within the branches. If a branch into which charge transfers exists a battery cell with a high charge level, that cell may be overcharged, thus shortening the battery pack's lifespan and potentially causing a safety hazard.

[0064] Therefore, accurately estimating the actual amount of charge in each battery cell when charging the battery pack stops at any time is of great significance for safe battery use and extending battery life.

[0065] The inventors of this application have noticed that, in order to accurately estimate the actual amount of charge in a battery cell when charging of the battery pack stops, they often only consider whether the open circuit voltage (OCV) between branches is equal and calculate the amount of charge transferred between battery cells. When determining the actual amount of charge in a battery cell after charging stops based on this amount of transferred charge, the obtained amount of charge often has a large error compared with the actual amount of charge in the battery cell after charging stops.

[0066] Based on the above considerations, and after in-depth research, the inventors have provided a charge balancing method, apparatus, electronic device, and readable storage medium. Specifically, for a battery pack including parallel branches, and each branch including at least one battery cell, by obtaining the first charge amount of each battery cell in the battery pack during the charging time, the charge increase of each battery cell during the charging time can be quickly determined. Next, based on the first charge amount of each battery cell in the battery pack and the target balancing voltage, the target balancing charge amount of each battery cell can be quickly determined. The target balancing charge amount can then be used as the actual charge amount charged into each battery cell after charge transfer, improving the accuracy of estimating the actual charge amount charged into the battery cell.

[0067] The technical solutions described in this application are applicable to batteries and electrical devices that use batteries. These electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. This application does not impose any special limitations on the aforementioned electrical devices.

[0068] The charge balancing method provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0069] Please see Figure 1 , Figure 1 This is a schematic flowchart of a charge balancing method provided in an embodiment of this application. The charge balancing method may include the following steps 110 to 120.

[0070] Step 110: Obtain the first charge amount of each of the multiple battery cells in the battery pack.

[0071] The battery pack includes parallel branches, each branch including at least one battery cell, and the first charge is the amount of charge charged into the battery cell during the charging time.

[0072] Step 120: Determine the target balanced charge of each battery cell based on the first charge and target balanced voltage of each battery cell in the battery pack.

[0073] Based on the above steps, the battery pack includes parallel branches. The number of parallel branches can be two or more, and there is no specific limitation here.

[0074] Due to limitations in battery manufacturing processes, or differences in the degree of utilization among individual battery cells, each cell may acquire a different amount of charge during the charging process of a battery pack. The initial charge amount of a battery cell during the charging time is defined as the amount of charge that a battery cell receives during the charging time. For each individual battery cell, the amount of charge received by that cell during the charging time can be obtained separately.

[0075] In one embodiment, during the charging process of the battery pack, the current flowing through each battery cell can be sampled. After charging stops, the sampled current value can be integrated based on the total charging time to obtain the amount of charge charged into each battery cell during the charging time, i.e., the first amount of charge charged into each battery cell during the charging time.

[0076] Each branch corresponds to a target equalization voltage, which can be the same or different for different branches. The target equalization voltage determines whether each branch has reached an equalization state. For example, the relationship between the target equalization voltage and the branch's open-circuit voltage can be used to determine whether a branch has reached an equalization state. The target equalization voltage for each branch can be preset, or it can be determined in real time based on preset voltage equalization conditions. By combining the target equalization voltage of each branch with the initial charge of each battery cell in the battery pack, the target equalization charge of each battery cell can be quickly determined. When the charge in a battery cell equals the target equalization charge, it indicates that the entire parallel circuit has reached an equalization state.

[0077] It is understood that the statement that the entire parallel circuit has reached a balanced state as mentioned in the embodiments of this application means that there is no longer any charge transfer between different branches, or that the amount of charge transferred between different branches can be ignored.

[0078] Each branch may include one or more battery cells; no specific limitation is made here. The open-circuit voltage of each branch can be obtained by summing the open-circuit voltages of each battery cell. Different charge levels in battery cells may result in different open-circuit voltages in the branches containing those cells. The open-circuit voltage of each battery cell can be calculated based on a preset open-circuit voltage conversion relationship. Optionally, the preset open-circuit voltage conversion relationship is a conversion relationship between the open-circuit voltage of a battery cell and its state of charge (SOC), which can be provided by the battery cell manufacturer.

[0079] In this embodiment, the open-circuit voltage of each battery cell branch can be determined based on the open-circuit voltage of each branch. By combining whether each branch has reached a balanced state, the first charge of each battery cell is adjusted, and finally the target balanced charge of each battery cell can be obtained.

[0080] According to the embodiments of this application, by obtaining the first charge amount of each battery cell in the battery pack during the charging time, the charge increase of each battery cell during the charging time can be quickly determined. Next, based on the target equalization voltage and the first charge amount of each battery cell in each battery pack, the target equalization charge amount of each battery cell can be quickly determined. The target equalization charge amount is the actual charge amount charged into each battery cell after charge transfer, improving the accuracy of estimating the actual charge amount charged into the battery cell.

[0081] In some embodiments, the preset voltage equalization condition includes: a second difference between the first open-circuit voltage of each branch in the parallel circuit and the average of the open-circuit voltages of all branches is less than a first preset voltage. Alternatively, a third difference between the largest and smallest first open-circuit voltages in the parallel circuits is less than a second preset voltage.

[0082] Specifically, the first preset voltage and the second preset voltage can be set according to the specific circumstances of the individual battery cells included in the actual battery pack. The first preset voltage may be equal to or different from the second preset voltage; no specific limitation is made here.

[0083] For example, the first preset voltage can be set to 1 millivolt (mV). When the second difference between the first open-circuit voltage of each branch in the parallel circuit and the average of the open-circuit voltages of all branches is less than 1 millivolt (mV), the entire parallel circuit reaches a balanced state. At this time, there is no longer any charge transfer between different branches, or the amount of charge transferred between different branches can be ignored.

[0084] The second preset voltage can be set to 1 millivolt (mV). When the third difference between the largest and smallest first open-circuit voltages in the parallel branches is less than 1 millivolt (mV), the entire parallel circuit has reached a balanced state. At this point, there is no longer any charge transfer between different branches, or the amount of charge transferred between different branches is negligible.

[0085] According to the preset voltage balancing conditions set in the embodiments of this application, by combining the magnitude relationship of the open circuit voltage between branches, it can be determined whether the parallel circuits in the battery pack have reached a balanced state, thereby improving the calculation speed of the balanced charge.

[0086] In some embodiments, the target balancing voltage is the open-circuit voltage of the branch where the battery cell is located, and the target balancing voltage satisfies a preset voltage balancing condition. Regarding the above step 120, it may include steps 121 and 122.

[0087] Step 121: Determine the first average charge amount of the battery cells in each branch and the second average charge amount of the battery cells in the battery pack according to the first charge amount of each battery cell in the battery pack.

[0088] Step 122: Determine the target balancing charge amount of each battery cell in each branch according to the first charge amount of each battery cell, the first average charge amount corresponding to each branch, the second average charge amount, and the target balancing voltage.

[0089] Exemplarily, the battery pack includes n branches connected in parallel with each other, and there are m battery cells on each branch. The average SOC of the single-cell battery on the x-th branch is denoted as SOCx, and the charge amount of the y-th single-cell battery on the x-th branch can be expressed as SOCxy, where x < n, y < m, and both m and n are positive integers. The first average charge amount of the battery cells in each branch can be calculated according to formula (1).

[0090]

[0091] The second average charge amount of the battery cells in the battery pack can be calculated according to formula (2).

[0092]

[0093] In the embodiments of the present application, according to the first charge amount of each battery cell, the first average charge amount corresponding to each branch, the second average charge amount, and the target balancing voltage, the first charge amount of each battery cell is adjusted, and finally the target balancing charge amount of each battery cell can be obtained.

[0094] According to the embodiments of the present application, through the first charge amount of each battery cell in the battery pack, the first average charge amount of the battery cells in each branch and the second average charge amount of the battery cells in the battery pack are determined, and the first charge amount of each battery cell is adjusted in combination with the target balancing voltage, so as to improve the accuracy of estimating the actual charge amount charged into the battery cell.

[0095] In some embodiments, adjusting the first charge amount of each battery cell includes steps 201 to step 203.

[0096] Step 201: For each branch, when the first average charge is not equal to the second average charge, perform a balance calculation based on the first charge of each battery cell in the branch, the first average charge of the branch, and the second average charge to determine the second charge of each battery cell in the branch.

[0097] Step 202: Determine the first open-circuit voltage of each branch based on the second charge quantity of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell.

[0098] Step 203: When the first open-circuit voltage of each branch meets the preset voltage equalization condition, the second charge of each battery cell in the branch is taken as the target equalization charge of each battery cell.

[0099] Specifically, when the first average charge of a branch is not equal to the second average charge, the charge within the battery cells in that branch will be transferred. For example, when the first average charge is greater than the second average charge, the charge within the corresponding battery cells in the branch will be moved out; when the first average charge is less than the second average charge, the charge within the corresponding battery cells in the branch will be moved in.

[0100] As a concrete example, the charge balancing calculation based on the first charge of each battery cell in the branch, the first average charge of the corresponding branch, and the second average charge can specifically involve adjusting the charge of each battery cell according to a preset charge balancing value. For instance, when the first average charge is greater than the second average charge, the first charge of each battery cell in the corresponding branch can be reduced by a preset charge balancing value; when the first average charge is less than the second average charge, the first charge of each battery cell in the corresponding branch can be increased by a preset charge balancing value.

[0101] For each battery cell, after adjusting the first charge once, the second charge of each battery cell can be obtained. Based on the conversion relationship between the second charge of each battery cell and the corresponding preset open-circuit voltage, the first open-circuit voltage of each branch can be obtained. Next, it can be determined whether the first open-circuit voltage of each branch meets the preset voltage balance condition. When the first open-circuit voltage of each branch meets the preset voltage balance condition, the entire parallel circuit can be considered to have reached a balanced state, and the second charge of each battery cell in the branch can be used as the target balanced charge of each battery cell.

[0102] According to the embodiments of this application, by performing a balanced calculation on the first charge of each battery cell in the battery pack, the second charge of each battery cell in the battery pack is obtained. By combining the open-circuit voltage of each branch with the preset voltage balance condition, it is determined whether the entire parallel circuit has reached a balanced state. This enables a rapid estimation of the actual charge of the battery cell and improves the accuracy of the estimated actual charge of the battery cell.

[0103] In some embodiments, the equalization calculation may specifically include the following steps: First, for each branch, calculate the absolute value of the first difference between the first average charge and the second average charge corresponding to the branch, and calculate the product of the absolute value of the first difference and a preset equalization parameter to obtain the charge equalization amount, wherein the preset parameter is greater than 0 and less than 1. Next, based on the charge equalization amount and the first charge of each battery cell in each branch, determine the second charge of each battery cell.

[0104] For example, for the x-th branch, the absolute value of the first difference between the first average charge and the second average charge corresponding to the x-th branch can be expressed as |SOCx - SOCtotal|. For example, the charge balance can be calculated according to formula (3).

[0105] SOCxy-a*∣SOCx-SOCtotal∣(3)

[0106] Where 'a' is a preset parameter, 0 <a<1。

[0107] The accuracy of charge balance calculation can be adjusted by changing the preset parameter 'a', thereby improving the estimation accuracy of the target balanced charge. The smaller 'a' is, the higher the accuracy of charge balance calculation. Conversely, the larger 'a' is, the higher the calculation efficiency of the target balanced charge. Optionally, the value of 'a' can be determined based on the computing power of the battery management system and the required calculation accuracy; no specific restrictions are placed on the value of 'a' here. After obtaining the charge balance of each battery cell for each branch, the second charge of each battery cell can be determined based on the charge balance and the first charge of each battery cell in each branch.

[0108] According to the embodiments of this application, the calculation efficiency or accuracy of the estimated target balanced charge can be easily adjusted by setting preset parameters. Then, the balanced charge of each battery cell is calculated, and combined with the first charge of each battery cell in each branch, the second charge of each battery cell is determined, thereby improving the accuracy of the estimated target balanced charge.

[0109] As a specific example, determining the second charge of each battery cell can specifically include: for each branch, when the first average charge of the branch is greater than the second average charge, calculating the difference between the first charge and the charge balance of each battery cell in the branch to obtain the second charge; when the first average charge of the branch is less than the second average charge, calculating the sum of the first charge and the charge balance of each battery cell in the branch to obtain the second charge.

[0110] According to the embodiments of this application, the charge balance of each battery cell is calculated, and combined with the first charge of each battery cell in each branch, the second charge of each battery cell is determined, thereby improving the accuracy of the estimated target balance charge.

[0111] When the first open-circuit voltage of each branch does not meet the preset voltage equalization condition, the second charge quantity of each battery cell needs to be adjusted for equalization until the first open-circuit voltage of each branch meets the preset voltage equalization condition. Specifically, the equalization adjustment process may include steps 204 to 207.

[0112] Step 204: When the first open-circuit voltage of at least one branch does not meet the preset voltage equalization condition, continue to perform equalization calculation based on the second charge of each battery cell in the branch, the first average charge of the branch, and the second average charge, and determine the third charge of each battery cell in the branch.

[0113] Step 205: Determine the second open-circuit voltage of each branch based on the third charge quantity of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell.

[0114] Step 206: When the second open-circuit voltage of each branch meets the preset voltage equalization condition, the third charge of each battery cell in the branch is taken as the target equalization charge of each battery cell.

[0115] Step 207: When the second open-circuit voltage of at least one branch does not meet the preset voltage equalization condition, iterative equalization calculation is performed based on the third charge of each battery cell in the branch, the first average charge of the branch, and the second average charge, until the target equalization charge of each battery cell is obtained.

[0116] For example, the balancing calculation based on the second charge of each battery cell in the branch, the first average charge of the branch, and the second average charge can specifically be performed by adjusting the charge of each battery cell according to a preset charge value. For instance, when the first average charge is greater than the second average charge, the second charge of each battery cell in the corresponding branch can be reduced by a preset charge balancing amount. When the first average charge is less than the second average charge, the second charge of each battery cell in the corresponding branch can be increased by a preset charge balancing amount.

[0117] For each battery cell, after adjusting the second charge once, the third charge of each battery cell can be obtained. Based on the conversion relationship between the third charge of each battery cell and the corresponding preset open-circuit voltage, the second open-circuit voltage of each branch can be obtained. When the second open-circuit voltage of each branch meets the preset voltage balance condition, the third charge of each battery cell in the branch is taken as the target balanced charge of each battery cell. When the second open-circuit voltage of at least one branch does not meet the preset voltage balance condition, iterative balance calculation needs to continue. That is, based on the first average charge, second average charge, and charge balance amount corresponding to each branch, the third charge of each battery cell is adjusted. After the third charge adjustment is completed, the adjusted third charge of each battery cell is obtained. The specific steps of the iterative balance calculation, and the specific steps for determining whether the adjusted charge can be used as the target balanced charge, can be found in the specific steps for determining the second charge of each battery cell based on the charge balance amount and the first charge of each battery cell in each branch, and will not be elaborated here.

[0118] According to the embodiments of this application, after the charge of each battery cell in the battery pack is adjusted once, it is immediately determined whether the open circuit voltage of each branch meets the preset voltage equalization condition, thereby enabling rapid estimation of the actual charge of the battery cell and improving the accuracy of the estimated actual charge of the battery cell.

[0119] In some embodiments, after stopping charging the battery pack, it can also be determined whether there are overcharged battery cells in the battery pack. Specifically, this may include steps 301 to 303.

[0120] Step 301: Obtain the fourth charge amount of each battery cell at a preset time, which is the time before charging begins.

[0121] Step 302: For each battery cell, calculate the sum of the target balanced charge and the fourth charge to obtain the fifth charge of the battery cell.

[0122] Step 303: When the fifth charge amount is greater than the preset charge amount, the detection result is obtained. The detection result includes the overcharge risk information of the battery cell.

[0123] Specifically, the preset time is the time before charging begins. The fourth charge is the remaining charge in each battery cell of the battery pack. For example, to obtain the fourth charge of each battery cell at the preset time, one can first obtain the open-circuit voltage of each battery cell at the preset time, and then calculate the fourth charge of each battery cell according to the preset open-circuit voltage conversion relationship corresponding to that battery cell.

[0124] For each battery cell, the sum of the target equilibrium charge and the fourth charge is calculated to obtain the fifth charge of the battery cell. The fifth charge is the actual charge charged into the battery cell when the entire parallel circuit has reached an equilibrium state.

[0125] In some embodiments, for each battery cell, the preset charge amount can be the maximum charge that the battery cell is allowed to be charged with; the preset charge amount can also be the preset rated charge amount of the battery cell, without specific limitations. After calculating the fifth charge amount, the relationship between the fifth charge amount and the preset charge amount is used to determine whether the battery cell has an overcharge risk. Specifically, when the fifth charge amount is greater than the preset charge amount, a detection result is obtained, which includes overcharge risk information for the battery cell. When the fifth charge amount is less than or equal to the preset charge amount, the detection result may include information indicating that the battery cell does not have an overcharge risk.

[0126] According to the embodiments of this application, after the battery pack finishes charging, the target balanced charge of each battery cell can be calculated quickly and accurately, which facilitates the calculation of the actual charge of each battery cell after the entire parallel circuit is balanced, and accurately determines whether there is a safety risk of overcharging in the battery cell.

[0127] To better understand the charge balancing method provided in the embodiments of this application, based on the same inventive concept, embodiments of the above-mentioned charge balancing method in practical applications are provided here for illustration.

[0128] Figure 2 This application provides a schematic flowchart of another charge equalization method according to an embodiment. (Combined with...) Figure 2 As shown, the charge balancing method may include steps 401 to 407.

[0129] Step 401: Obtain the first charge amount of each battery cell in the battery pack during the charging time.

[0130] Step 402: Based on the first charge of each battery cell in the battery pack, determine the first average charge of each battery cell in each branch and the second average charge of each battery cell in the battery pack.

[0131] Step 403: For each branch, calculate the absolute value of the first difference between the first average charge and the second average charge, and calculate the product of the absolute value of the first difference and the preset balance parameter to obtain the charge balance amount, wherein the preset parameter is greater than 0 and less than 1.

[0132] Step 404: Determine the second charge of each battery cell based on the charge balance and the first charge of each battery cell in each branch.

[0133] Specifically, for each branch, when the first average charge of the branch is greater than the second average charge, the difference between the first charge and the charge balance of each battery cell in the branch is calculated to obtain the second charge. When the first average charge of the branch is less than the second average charge, the sum of the first charge and the charge balance of each battery cell in the branch is calculated to obtain the second charge.

[0134] Step 405: Determine the first open-circuit voltage of each branch based on the second charge quantity of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell.

[0135] Step 406: When the first open-circuit voltage of at least one branch does not meet the preset voltage balancing condition, the second charge is used as the first charge, and step 404 is executed again until the calculated second charge makes the open-circuit voltage of each branch meet the preset voltage balancing condition.

[0136] Step 407: When the first open-circuit voltage of each branch meets the preset voltage equalization condition, the second charge of each battery cell in the branch is taken as the target equalization charge of each battery cell.

[0137] Step 408: Obtain the first charge amount of each battery cell at a preset time, which is the time before charging begins.

[0138] Step 409: For each battery cell, calculate the sum of the target balanced charge and the first charge to obtain the second charge of the battery cell.

[0139] Step 410: When the second charge amount is greater than the preset charge amount, the detection result is obtained. The detection result includes the overcharge risk information of the battery cell.

[0140] In this embodiment, for a battery pack including parallel branches and each branch including at least one battery cell, the amount of charge added to each battery cell during the charging time can be quickly determined by obtaining the first charge amount of each battery cell in the battery pack. Next, based on the target equalization voltage of the branch containing the battery cell that meets the preset voltage equalization condition and the first charge amount of each battery cell in each battery pack, the target equalization charge amount of each battery cell is determined. This target equalization charge amount can then be used as the actual charge added to each battery cell after charge transfer, improving the accuracy of estimating the actual charge added to the battery cell.

[0141] Based on the same inventive concept, this application also provides a charge balancing device 300 corresponding to the above-described charge balancing method. (Specifically combined with...) Figure 3 Please provide a detailed explanation.

[0142] Figure 3 This is a schematic diagram of the structure of a charge equalization device provided in an embodiment of this application. The charge equalization device 300 may include an acquisition module 310 and a processing module 320.

[0143] The acquisition module 310 is used to acquire the first charge amount of each battery cell in the multiple battery cells of the battery pack, wherein the battery pack includes parallel branches, each branch includes at least one battery cell, and the first charge amount is the amount of charge charged into the battery cell during the charging time.

[0144] The processing module 320 is used to determine the target balanced charge of each battery cell based on the first charge of each battery cell in the battery pack and the target balanced voltage.

[0145] According to the embodiments of this application, by obtaining the first charge amount of each battery cell in the battery pack during the charging time, the charge increase of each battery cell during the charging time can be quickly determined. Next, based on the target equalization voltage of the branch where the battery cell is located, which meets the preset voltage equalization condition, and the first charge amount of each battery cell in each battery pack, the target equalization charge amount of each battery cell is determined. The target equalization charge amount can be used as the actual charge amount charged into each battery cell after charge transfer, thereby improving the accuracy of estimating the actual charge amount charged into the battery cell.

[0146] In some embodiments, the target equalization voltage is the open-circuit voltage of the branch where the battery cell is located, and the target equalization voltage satisfies the preset voltage equalization condition.

[0147] The acquisition module 310 is also used to acquire the first charge amount of each battery cell at a preset time, which is the time before charging begins;

[0148] The processing module 320 is also used to calculate the sum of the target balanced charge and the first charge for each battery cell to obtain the second charge of the battery cell.

[0149] The processing module 320 is also used to obtain a detection result when the second charge amount is greater than the preset charge amount. The detection result includes overcharge risk information of the battery cell.

[0150] According to the embodiments of this application, after the battery pack finishes charging, the target balanced charge of each battery cell can be quickly and accurately calculated. This facilitates the calculation of the actual charge of each battery cell in the entire parallel circuit after equalization, and allows for accurate determination of whether there is a safety risk of overcharging in a battery cell.

[0151] In some embodiments, the processing module 320 is further configured to determine the first average charge of the battery cells in each branch and the second average charge of the battery cells in the battery pack based on the first charge of each battery cell in the battery pack.

[0152] The processing module 320 is also used to determine the target balanced charge of each battery cell in each branch based on the first charge of each battery cell, the first average charge of each branch, the second average charge, and the target balanced voltage.

[0153] According to the embodiments of this application, the first average charge of each battery cell in the battery pack and the second average charge of each battery cell in the battery pack are determined by the first charge of each battery cell in the battery pack. The first charge of each battery cell is adjusted in combination with the target equalization voltage, thereby improving the accuracy of estimating the actual charge of the battery cell.

[0154] In some embodiments, the processing module 320 is further configured to, for each branch, when the first average charge is not equal to the second average charge, perform an equalization calculation based on the first charge of each battery cell in the branch, the first average charge of the branch, and the second average charge to determine the second charge of each battery cell in the branch.

[0155] The processing module 320 is also used to determine the first open-circuit voltage of each branch based on the second charge of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell.

[0156] The processing module 320 is also used to take the second charge of each battery cell in the branch as the target balanced charge of each battery cell when the first open-circuit voltage of each branch meets the preset voltage equalization condition.

[0157] According to the embodiments of this application, by performing a balanced calculation on the first charge of each battery cell in the battery pack, the second charge of each battery cell in the battery pack is obtained. By combining the open-circuit voltage of each branch with the preset voltage balance condition, it is determined whether the entire parallel circuit has reached a balanced state. This enables a rapid estimation of the actual charge of the battery cell and improves the accuracy of the estimated actual charge of the battery cell.

[0158] In some embodiments, the processing module 320 is further configured to, when the first open-circuit voltage of at least one branch does not meet the preset voltage equalization condition, continue to perform equalization calculations based on the second charge of each battery cell in the branch, the first average charge of the branch, and the second average charge, to determine the third charge of each battery cell in the branch.

[0159] The processing module 320 is also used to determine the second open-circuit voltage of each branch based on the third charge quantity of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell.

[0160] The processing module 320 is also used to take the third charge of each battery cell in the branch as the target balanced charge of each battery cell when the second open-circuit voltage of each branch meets the preset voltage equalization condition.

[0161] The processing module 320 is also used to perform iterative equalization calculations based on the third charge of each battery cell in the branch, the first average charge of the branch, and the second average charge when the second open-circuit voltage of at least one branch does not meet the preset voltage equalization conditions, until the target equalization charge of each battery cell is obtained.

[0162] According to the embodiments of this application, after the charge of each battery cell in the battery pack is adjusted once, it is immediately determined whether the open circuit voltage of each branch meets the preset voltage equalization condition, thereby enabling rapid estimation of the actual charge of the battery cell and improving the accuracy of the estimated actual charge of the battery cell.

[0163] In some embodiments, the processing module 320 is further configured to calculate the absolute value of the first difference between the first average charge and the second average charge corresponding to each branch, and calculate the product of the absolute value of the first difference and a preset balance parameter to obtain the charge balance amount, wherein the preset parameter is greater than 0 and less than 1.

[0164] The processing module 320 is also used to determine the second charge of each battery cell based on the charge balance and the first charge of each battery cell in each branch.

[0165] According to the embodiments of this application, the charge balance of each battery cell is calculated, and combined with the first charge of each battery cell in each branch, the second charge of each battery cell is determined, thereby improving the accuracy of the estimated target balance charge.

[0166] In some embodiments, the processing module 320 is further configured to, for each branch, calculate the difference between the first charge and the charge balance of each battery cell in the branch when the first average charge of the branch is greater than the second average charge, and obtain the second charge.

[0167] The processing module 320 is also used to calculate the sum of the first charge and the charge balance of each battery cell in the branch when the first average charge of the branch is less than the second average charge, so as to obtain the second charge.

[0168] According to the embodiments of this application, the charge balance of each battery cell is calculated, and combined with the first charge of each battery cell in each branch, the second charge of each battery cell is determined, thereby improving the accuracy of the estimated target balance charge.

[0169] In some embodiments, the preset voltage equalization conditions include:

[0170] The second difference between the first open-circuit voltage of each branch in the parallel branches and the average value of the open-circuit voltages of all branches is less than the first preset voltage.

[0171] or,

[0172] The third difference between the largest and smallest first open-circuit voltages in the parallel branches is less than the second preset voltage.

[0173] According to the preset voltage balancing conditions set in the embodiments of this application, by combining the magnitude relationship of the open circuit voltage between branches, it is determined whether the battery pack has reached a balanced state, thereby improving the calculation speed of the balanced charge.

[0174] It is understood that the charge equalization device 300 in this application embodiment can correspond to the execution subject of the charge equalization method provided in this application embodiment. The specific details of the operation and / or function of each module / unit of the charge equalization device 300 can be found in the description of the corresponding part of the charge equalization method described in the above-described embodiment of this application, and can achieve its corresponding technical effect. For the sake of brevity, it will not be repeated here.

[0175] Figure 4 A schematic diagram of the structure of an electronic device according to an embodiment of this application is shown. Figure 4 As shown, the device may include a processor 501 and a memory 502 storing computer program instructions.

[0176] Specifically, the processor 501 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0177] Memory 502 may include mass storage for information or instructions. For example, and not limitingly, memory 502 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. In one instance, memory 502 may include removable or non-removable (or fixed) media, or memory 502 may be a non-volatile solid-state memory. Memory 502 may be internal or external to an electronic device.

[0178] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of this application.

[0179] The processor 501 reads and executes the computer program instructions stored in the memory 502 to implement the method described in the embodiments of this application and achieve the corresponding technical effects achieved by executing the method in the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0180] In one example, the electronic device may also include a communication interface 503 and a bus 510. Wherein, as... Figure 4 As shown, the processor 501, memory 502, and communication interface 503 are connected through bus 510 and complete communication with each other.

[0181] The communication interface 503 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0182] Bus 510 includes hardware, software, or both, that couples components of an online information flow metering device together. For example, and not as a limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 510 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0183] The electronic device can execute the charge balancing method in the embodiments of this application, thereby achieving the corresponding technical effects of the charge balancing method described in the embodiments of this application.

[0184] Furthermore, in conjunction with the charge balancing methods in the above embodiments, this application embodiment can provide a readable storage medium for implementation. This readable storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the charge balancing methods in the above embodiments. Examples of readable storage media can be non-transitory machine-readable media, such as electronic circuits, semiconductor memory devices, read-only memory (ROM), floppy disks, compact disc read-only memory (CD-ROM), optical disks, hard disks, etc.

[0185] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0186] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (ROM), flash memory, erasable read-only memory (EROM), floppy disks, compact disc read-only memory (CD-ROM), optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0187] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0188] Furthermore, in conjunction with the charge equalization method, apparatus, and readable storage medium described in the above embodiments, this application embodiment can provide a computer program product for implementation. When the instructions in the computer program product are executed by the processor of an electronic device, the electronic device causes the electronic device to perform any of the charge equalization methods described in the above embodiments.

[0189] The aspects of this application have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0190] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A charge balancing method, characterized in that, The method includes: The first charge amount of each battery cell in a battery pack is obtained, wherein the battery pack includes parallel branches, each branch includes at least one battery cell, and the first charge amount is the amount of charge charged into the battery cell during the charging time. Based on the first charge of each battery cell in the battery pack, determine the first average charge of the battery cells in each branch and the second average charge of the battery cells in the battery pack; The target balanced charge of each battery cell in each branch is determined based on the first charge of each battery cell, the first average charge of each branch, the second average charge, and the target balanced voltage.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the fourth charge amount of each of the battery cells at a preset time, where the preset time is the time before charging begins; For each of the battery cells, the sum of the target balanced charge and the fourth charge is calculated to obtain the fifth charge of the battery cell; When the fifth charge amount is greater than the preset charge amount, a detection result is obtained, and the detection result includes the overcharge risk information of the battery cell.

3. The method according to claim 1, characterized in that, The target equalization voltage is the open-circuit voltage of the branch where the battery cell is located, and the target equalization voltage satisfies the preset voltage equalization condition.

4. The method according to claim 1, characterized in that, The step of determining the target balanced charge of each battery cell in each branch based on the first charge of each battery cell, the first average charge of each branch, the second average charge, and the target balanced voltage includes: For each branch, when the first average charge is not equal to the second average charge, the second charge of each battery cell in the branch is determined by balancing calculation based on the first charge of each battery cell in the branch, the first average charge of the branch, and the second average charge. The first open-circuit voltage of each branch is determined based on the second charge of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell. When the first open-circuit voltage of each branch meets the preset voltage equalization condition, the second charge of each battery cell in the branch is taken as the target equalization charge of each battery cell.

5. The method according to claim 4, characterized in that, The method further includes: When the first open-circuit voltage of at least one of the branches does not meet the preset voltage equalization condition, the third charge of each battery cell in the branch is determined by continuing the equalization calculation based on the second charge of each battery cell in the branch, the first average charge of the branch, and the second average charge. The second open-circuit voltage of each branch is determined based on the third charge of each battery cell and the preset open-circuit voltage conversion relationship of the battery cell. When the second open-circuit voltage of each of the branches meets the preset voltage equalization condition, the third charge of each battery cell in the branch is taken as the target equalization charge of each battery cell. When the second open-circuit voltage of at least one of the branches does not meet the preset voltage equalization condition, iterative equalization calculation is performed based on the third charge of each battery cell in the branch, the first average charge of the branch, and the second average charge until the target equalization charge of each battery cell is obtained.

6. The method according to claim 4, characterized in that, The step of determining the second charge of each battery cell in the branch by performing an equalization calculation based on the first charge of each battery cell in the branch, the first average charge of the branch, and the second average charge includes: For each branch, calculate the absolute value of the first difference between the first average charge and the second average charge corresponding to the branch, and calculate the product of the absolute value of the first difference and the preset balance parameter to obtain the charge balance amount, wherein the preset balance parameter is greater than 0 and less than 1. The second charge of each battery cell is determined based on the charge balance and the first charge of each battery cell in each branch.

7. The method according to claim 6, characterized in that, The step of determining the second charge of each battery cell based on the charge balance and the first charge of each battery cell in each branch includes: For each branch, when the first average charge of the branch is greater than the second average charge, the difference between the first charge of each battery cell in the branch and the charge balance is calculated to obtain the second charge. When the first average charge of the branch is less than the second average charge, the sum of the first charge of each battery cell in the branch and the charge balance is calculated to obtain the second charge.

8. The method according to claim 4, characterized in that, The preset voltage equalization conditions include: The second difference between the first open-circuit voltage of each branch in the parallel branches and the average value of the open-circuit voltages of all branches is less than the first preset voltage. or, The third difference between the largest and smallest first open-circuit voltages in the parallel branches is less than the second preset voltage.

9. A charge balancing device, characterized in that, The device includes: The acquisition module is used to acquire the first charge amount of each battery cell in a battery pack, wherein the battery pack includes parallel branches, each branch includes at least one battery cell, and the first charge amount is the amount of charge charged into the battery cell during the charging time. The processing module is configured to determine, based on the first charge of each battery cell in the battery pack, the first average charge of each battery cell in the battery pack and the second average charge of each battery cell in the battery pack; and to determine, based on the first charge of each battery cell, the first average charge of each branch, the second average charge, and the target equalization voltage, the target equalization charge of each battery cell in each branch.

10. An electronic device, characterized in that, It includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the charge balancing method as described in any one of claims 1 to 8.

11. A readable storage medium, characterized in that, The readable storage medium stores computer program instructions that, when executed by a processor, implement the charge balancing method as described in any one of claims 1 to 8.

12. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device performs the charge balancing method as described in any one of claims 1 to 8.

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