Balancing control method, battery manager and vehicle

Abstract

The application discloses a kind of equalization control method, battery manager and vehicle, equalization control method includes: obtaining the single body voltage of each single body battery in battery pack at charging cutoff time;Determine the actual voltage difference of the single body voltage of each single body battery and the lowest voltage in all single body voltage;According to the actual voltage difference of each single body battery corresponding, determine the equalization duration of each single body battery.The method can accurately adjust each single body battery to be consistent, maximize the ability of battery pack.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a balanced control method, a battery manager, and a vehicle. Background Technology

[0002] During the manufacturing process, although theoretically the battery capacity is the same, there are deviations in the capacity of the cells. Each cell cannot be completely identical, and the deviation may increase during use. The maximum discharge capacity of a battery system formed by multiple cells connected in series is limited by the capacity difference.

[0003] In existing technologies, the maximum discharge capacity of a series battery system is achieved by balancing the charge of each cell. However, this may result in the selection of the wrong cells for balancing or inaccurate balancing time, leading to a persistently low rechargeable capacity of the battery without timely improvement. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present invention is to propose a balancing control method that can accurately adjust each individual cell to be more uniform, thereby maximizing the capacity of the battery pack.

[0005] The second objective of this invention is to provide a battery manager.

[0006] The third objective of this invention is to provide a computer storage medium.

[0007] The fourth objective of this invention is to provide a computer program product.

[0008] The fifth objective of this invention is to provide a vehicle.

[0009] To address the aforementioned problems, a first aspect of the present invention proposes an equalization control method, comprising: acquiring the individual cell voltage of each cell in the battery pack at the charging cutoff time; determining the actual voltage difference between the individual cell voltage of each cell and the lowest voltage among all individual cell voltages; and determining the equalization time of each individual cell based on the actual voltage difference corresponding to each individual cell.

[0010] According to the equalization control method of the present invention, the individual cell voltage of each cell in the battery pack is obtained at the charging cutoff time, avoiding the inability to accurately measure the individual cell voltage of each cell in the battery pack due to polarization. Then, based on the actual voltage difference corresponding to each individual cell, the equalization time of each individual cell can be determined more accurately. By equalizing each individual cell according to this equalization time, the individual cells can be accurately adjusted to be more consistent, thereby maximizing the capacity of the battery pack.

[0011] In some embodiments, determining the balancing time of each individual cell based on the actual voltage difference corresponding to each individual cell includes: determining the balancing capacity of each individual cell based on the actual voltage difference corresponding to each individual cell and the rated capacity of the individual cell; and determining the balancing time of each individual cell based on the balancing capacity of each individual cell.

[0012] In some embodiments, determining the balanced capacity of each individual cell based on the actual voltage difference corresponding to each individual cell and the rated capacity of the individual cell includes: determining the actual balanced SOC value of each individual cell by querying a standard correspondence based on the actual voltage difference corresponding to each individual cell, wherein the standard correspondence is a correspondence between the voltage difference and the balanced SOC value established based on the charging voltage-SOC relationship curve of the individual cell; and determining the balanced capacity of each individual cell based on the actual balanced SOC value of each individual cell and the rated capacity.

[0013] In some embodiments, the standard correspondence includes multiple data point pairs of voltage differences and balanced SOC values. The voltage differences in the data point pairs are discretely distributed. The actual balanced SOC value of each individual cell is determined by querying the standard correspondence based on the actual voltage difference corresponding to each individual cell. This includes: if the actual voltage difference exists in the data point pair, determining the actual balanced SOC value by querying the data point pair based on the actual voltage difference; if the actual voltage difference does not exist in the data point pair, determining the adjacent voltage differences of the actual voltage difference in the data point pair, and determining the actual balanced SOC value based on the actual voltage difference and the adjacent voltage differences.

[0014] In some embodiments, the adjacent voltage difference includes a first voltage difference and a second voltage difference. Determining the actual equilibrium SOC value based on the actual voltage difference and the adjacent voltage difference includes: when the actual voltage difference is greater than the first voltage difference and less than the second voltage difference, forming a linear model based on the data point pair where the first voltage difference is located and the data point pair where the second voltage difference is located; and determining the actual equilibrium SOC value based on the actual voltage difference and the linear model.

[0015] In some embodiments, the adjacent voltage difference is the lowest voltage difference or the highest voltage difference in the data point pair. Determining the actual balanced SOC value based on the actual voltage difference and the adjacent voltage differences includes: if the actual voltage difference is less than the lowest voltage difference, using the balanced SOC value corresponding to the lowest voltage difference as the actual balanced SOC value; or, if the actual voltage difference is greater than the highest voltage difference, using the balanced SOC value corresponding to the highest voltage difference as the actual balanced SOC value.

[0016] In some embodiments, determining the balanced capacity of each individual cell based on the actual balanced SOC value and the rated capacity includes: using the product of the actual balanced SOC value and the rated capacity as the balanced capacity.

[0017] In some embodiments, determining the balancing duration of each individual cell based on the balancing capacity of each individual cell includes: determining the balancing current value of the individual cell; and using the ratio of the balancing capacity to the balancing current value as the balancing duration.

[0018] In some embodiments, the method further includes: performing equalization control on each individual cell according to the equalization duration of each individual cell, until the individual cell meets the stop equalization condition.

[0019] In some embodiments, the balancing stop condition includes any one of the following: the balancing control duration for the individual cell reaches the balancing duration; or the individual cell voltage is lower than a preset threshold.

[0020] A second aspect of the present invention provides a battery manager, comprising: at least one processor; a memory communicatively connected to at least one processor; wherein the memory stores a computer program executable by at least one processor, and the at least one processor executes the computer program to implement the equalization control method of the above embodiments.

[0021] According to the battery manager of the present invention, the equalization control method is implemented by the processor executing the computer program stored in the memory, which can accurately adjust each individual cell to be more consistent and maximize the capacity of the battery pack.

[0022] A third aspect of the present invention provides a computer storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the equalization control method of the above embodiments.

[0023] A fourth aspect of the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the equalization control method described above.

[0024] A fifth aspect of the present invention provides a vehicle including the battery manager described in the above embodiments.

[0025] According to the vehicle of the present invention, each individual battery cell can be precisely adjusted to be consistent, thereby maximizing the capacity of the battery pack.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart of an equalization control method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the battery pack charging voltage; Figure 3 This is a schematic diagram of the charging voltage-SOC relationship according to an embodiment of the present invention; Figure 4 This is a structural block diagram of a battery manager according to an embodiment of the present invention; Figure 5 This is a structural block diagram of a vehicle according to an embodiment of the present invention.

[0028] Figure label: 1000 vehicles; Battery Management System 100; Processor 1; Memory 2. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0030] When multiple lithium iron phosphate cells are connected in series, the maximum discharge capacity of the entire series system is limited by the cell that is the first to be discharged at the discharge cutoff time. This cell may not have been fully charged, and the cell that is fully charged first may be another cell. This will cause the capacity of the series battery to be lower than the minimum capacity of a single cell, and the maximum discharge capacity of the entire series battery system will be limited. This limitation becomes more and more significant as the number of cells connected in series increases. At this time, it is necessary to balance the charge of each cell so that the maximum discharge capacity of the entire series battery system can be brought into play, that is, the cell that is fully charged first is discharged first.

[0031] In existing technologies, the voltage difference between the current cell and the lowest voltage cell is usually determined. When the voltage difference is greater than a certain value, the equalization switch of that cell is turned on to discharge the cell. When the voltage difference is not met, the equalization switch of the cell is turned off. The equalization switch is turned on for a fixed duration for cells with the voltage difference met. However, this duration may not represent the battery's proper equalization duration. Therefore, the equalization method in existing technologies may not be balancing the correct cells, or even the equalization duration may be unreasonable, resulting in low equalization efficiency and a persistently low rechargeable capacity of the battery without timely improvement.

[0032] To address the aforementioned issues, the first aspect of this invention proposes a balanced control method that can accurately adjust each individual cell to be more consistent, thereby maximizing the capacity of the battery pack.

[0033] The following is for reference. Figure 1 The equalization control method according to an embodiment of the present invention is described. The equalization control method includes steps S1-S3, and the specific steps are as follows.

[0034] Step S1: Obtain the individual cell voltage of each cell in the battery pack at the charging cutoff time.

[0035] Specifically, such as Figure 2 As shown, the time when the battery pack is fully charged is determined by the cell that first reaches the charging cutoff voltage, while the time when the battery pack is discharged is determined by the cell that first reaches the discharging cutoff voltage. At the charging cutoff time, the individual cell in the battery pack reaches the charging cutoff voltage first, at which point the battery pack is fully charged and the charging current is 0. However, when the battery pack is not fully charged, due to the influence of polarization, the individual cell voltages obtained at this time will be too high. Using this voltage to estimate the cell capacity is not accurate enough, which leads to misbalancing. Ultimately, the charging capacity of the battery pack is low for a long time and cannot be improved in time.

[0036] On the other hand, since the charging time of the battery pack is not fixed, if the battery pack is slow-charged, the charging time can reach 10 hours. It is not feasible to store the voltage of multiple cells at multiple times. Such a solution would require several hours of storage space, and it is difficult for the chip to store so much data for querying. Opening a fixed storage data structure or using dynamic allocation storage cannot be practically used in physical systems. Even if the storage is completed, there is no way to deal with the failure of fast querying of large amounts of data on a chip with limited computing resources, so its practicality is low.

[0037] To improve the accuracy of equalization adjustment, this application selects to acquire the individual cell voltage of each cell in the battery pack at the charging cutoff moment. At this time, there is no polarization effect, and the acquired individual cell voltage has high accuracy. Equalization adjustment based on this individual cell voltage can avoid false equalization and has high practicality. The charging cutoff voltage can be set according to actual conditions. For example, the charging cutoff voltage can be set to 3.45V, 3.55V, or 3.6V, etc., without specific limitations.

[0038] It should be noted that, due to the presence of connecting metal plates and other devices in the sampling circuit of a single cell, the sampled single cell voltage is actually superimposed with the voltage of the connecting plates. This may result in some single cells having a high single cell voltage but a lower actual capacity. Using this voltage to estimate the cell capacity is not accurate enough. This application selects to obtain the single cell voltage at the charging cutoff moment, when the charging current is 0 and there is no voltage on the connecting metal plates. Therefore, the single cell voltage of each single cell is not affected by the connecting metal plates, and the measurement of the single cell voltage is more accurate.

[0039] Step S2: Determine the actual voltage difference between the individual cell voltage of each cell and the lowest voltage among all individual cell voltages.

[0040] Specifically, the individual cell voltages are compared to obtain the lowest voltage. Then, the actual voltage difference between the individual cell voltage and the lowest voltage is calculated. The actual voltage difference can reflect the difference in capacity between individual cells. Adjusting the actual voltage difference can achieve capacity balance among individual cells.

[0041] Step S3: Determine the balancing time for each individual cell based on the actual voltage difference corresponding to each individual cell.

[0042] Specifically, if the battery pack is fully charged and the voltage of each individual cell is the same, the first cell to be fully charged will also be discharged at the battery pack's discharge cutoff time, thus maximizing the battery pack's capacity. Therefore, it is necessary to determine the actual voltage difference between the voltage of each individual cell and the lowest voltage among all cells. This difference can be adjusted to zero by discharging the individual cells, ensuring that the voltage of each individual cell is the same, i.e., the lowest voltage, thereby maximizing the battery pack's capacity.

[0043] According to the equalization control method of the present invention, the individual cell voltage of each cell in the battery pack is obtained at the charging cutoff time, avoiding the inability to accurately measure the individual cell voltage of each cell in the battery pack due to polarization. Then, based on the actual voltage difference corresponding to each individual cell, the equalization time of each individual cell can be determined more accurately. By equalizing each individual cell according to this equalization time, the individual cells can be accurately adjusted to be more consistent, thereby maximizing the capacity of the battery pack.

[0044] In some embodiments, the balancing time of each individual cell is determined based on the actual voltage difference corresponding to each individual cell, including determining the balancing capacity of each individual cell based on the actual voltage difference corresponding to each individual cell and the rated capacity of the individual cell; and determining the balancing time of each individual cell based on the balancing capacity of each individual cell.

[0045] Specifically, the voltage of each individual cell corresponds to its SOC. The SOC required for balancing each individual cell can be obtained based on the actual voltage difference. Then, the amount of electricity that each individual cell needs to release, i.e. the balancing capacity, can be determined by combining the rated capacity of the individual cell. And the balancing time corresponding to each individual cell can be determined based on the balancing capacity of each individual cell.

[0046] In some embodiments, the balanced capacity of each individual cell is determined based on the actual voltage difference and the rated capacity of each individual cell. This includes determining the actual balanced SOC value of each individual cell by querying a standard correspondence based on the actual voltage difference, wherein the standard correspondence is the correspondence between the voltage difference and the balanced SOC value established based on the charging voltage-SOC relationship curve of the individual cell; and determining the balanced capacity of each individual cell based on the actual balanced SOC value and the rated capacity of each individual cell.

[0047] Specifically, the actual balanced SOC value of each individual cell can be queried through Tables 1 and 2, and the standard correspondence between Tables 1 and 2 is based on... Figure 3 The charging voltage-SOC relationship shown is established. Figure 3 This is a schematic diagram of the charging voltage-SOC relationship curve for a single battery cell. Among them, Figure 3 The charging voltage-SOC relationship curve shown can be obtained by charging to 3.65V with a constant current of 0.05C, while the standard correspondences shown in Tables 1 and 2 can be pre-stored in the battery management system.

[0048] Table 1

[0049] Table 2

[0050] In some embodiments, the standard correspondence includes multiple data point pairs of voltage differences and balanced SOC values. The voltage differences in the data point pairs are discretely distributed. The actual balanced SOC value of each individual cell is determined by querying the standard correspondence based on the actual voltage difference corresponding to each individual cell. This includes determining the actual balanced SOC value by querying the data point pairs based on the actual voltage difference when there is an actual voltage difference in the data point pairs; and determining the actual balanced SOC value based on the actual voltage difference and the adjacent voltage differences when there is no actual voltage difference in the data point pairs.

[0051] Specifically, if there is a voltage difference in the data point pair in the standard correspondence that perfectly matches the actual voltage difference of a single cell, the corresponding balanced SOC value can be directly read as the actual balanced SOC value. However, in actual situations, there may be cases where there is no data point directly corresponding to the actual voltage difference. In such cases, the actual balanced SOC value can be estimated based on the adjacent voltage differences of the actual voltage difference using an interpolation method. The interpolation method can be linear interpolation, polynomial interpolation, or spline interpolation, etc., and no specific restrictions are imposed here.

[0052] In some embodiments, the adjacent voltage difference includes a first voltage difference and a second voltage difference. The actual equilibrium SOC value is determined based on the actual voltage difference and the adjacent voltage difference. This includes forming a linear model based on the data point pair where the first voltage difference is located and the data point pair where the second voltage difference is located when the actual voltage difference is greater than the first voltage difference and less than the second voltage difference. The actual equilibrium SOC value is then determined based on the actual voltage difference and the linear model.

[0053] Specifically, if there is no directly corresponding data point for the actual voltage difference, the actual equilibrium SOC value can be determined by linear interpolation. Both the first voltage difference and the second voltage difference have corresponding equilibrium SOC values. Based on the above, a linear model is constructed, with the first voltage difference and the second voltage difference as independent variables and their corresponding equilibrium SOC values ​​as dependent variables. The slope and intercept of the linear model can then be calculated. Finally, the actual voltage difference can be substituted to determine the actual equilibrium SOC value.

[0054] In some embodiments, the adjacent voltage difference is the lowest voltage difference or the highest voltage difference in the data point pair. The actual balanced SOC value is determined based on the actual voltage difference and the adjacent voltage differences. This includes taking the balanced SOC value corresponding to the lowest voltage difference as the actual balanced SOC value when the actual voltage difference is less than the lowest voltage difference; or taking the balanced SOC value corresponding to the highest voltage difference as the actual balanced SOC value when the actual voltage difference is greater than the highest voltage difference.

[0055] Specifically, the actual voltage difference may exceed the range of the data point pair, i.e., it may be lower than the minimum voltage difference or higher than the maximum voltage difference. In this case, the actual equalization SOC value cannot be determined by linear interpolation. In this situation, if the actual voltage difference is lower than the minimum voltage difference, the equalization SOC value corresponding to the minimum voltage difference is taken as the actual equalization SOC value; conversely, if the actual voltage difference is higher than the maximum voltage difference, the equalization SOC value corresponding to the maximum voltage difference is taken as the actual equalization SOC value.

[0056] In some embodiments, the balanced capacity of each individual cell is determined based on the actual balanced SOC value and the rated capacity of each individual cell, including using the product of the actual balanced SOC value and the rated capacity as the balanced capacity.

[0057] Specifically, the voltage of each individual cell corresponds to its SOC. The SOC value that each individual cell needs to balance, i.e. the actual balanced SOC value, can be obtained based on the actual voltage difference. Then, referring to Formula 1, the balanced capacity of each individual cell can be determined in combination with the rated capacity of the individual cell, and the corresponding balancing time can be determined based on the balanced capacity of each individual cell.

[0058] delta_SOC_I=delta(SOC)×C formula 1 Where delta_SOC_I is the equalization capacity of each individual cell; C is the rated capacity of the cell; and delta(SOC) is the SOC value that needs to be equalized corresponding to the actual voltage difference.

[0059] In some embodiments, the balancing time of each individual cell is determined based on the balancing capacity of each individual cell, including determining the balancing current value of the individual cell; and the ratio of the balancing capacity to the balancing current value is used as the balancing time.

[0060] Specifically, by connecting individual battery cells in series with an equalization resistor and an equalization switch to form an equalization circuit, the individual battery cells can be balanced and adjusted. Closing the equalization switch connects the equalization resistor, which releases excess capacity from the individual battery cells. The equalization switch is disconnected after the equalization period has elapsed, ultimately achieving accurate adjustment of each individual battery cell to be as uniform as possible, maximizing the battery pack's capacity. The resistance value of the equalization resistor can be set according to actual conditions, such as 20Ω, 22Ω, or 25Ω, etc., without specific limitations.

[0061] For example, the equalization switch uses a transistor. Based on the fixed voltage drop between the transistor and the equalization resistor, the equalization current remains constant. Therefore, the equalization duration can be calculated after obtaining the equalization capacity.

[0062] Since the balancing current value is fixed, the balancing time is only affected by the balancing capacity. During the balancing process, the balancing time can be obtained by referring to Formula 2.

[0063] Formula 2 Where t is the equilibrium duration, To balance the current.

[0064] In some embodiments, the method further includes equalization control of each individual cell based on the equalization duration of each individual cell, until the individual cell meets the stop equalization condition.

[0065] Specifically, in order to ensure that each individual cell is consistent and to avoid abnormalities in the individual cells during the equalization process, each individual cell must be monitored in real time during the equalization process. When all individual cells meet the conditions for stopping equalization, the equalization control is stopped.

[0066] In some embodiments, the balancing stop condition includes any one of the following: the balancing control duration of a single cell reaches the balancing duration; the single cell voltage is lower than a preset threshold.

[0067] Specifically, when the equalization control time of a single cell reaches the equalization time, it means that the single cell has become consistent with the single cell corresponding to the lowest voltage. At this time, the single cell can be controlled to exit the equalization control. However, if the single cell voltage has fallen below the preset threshold during the equalization adjustment process, continuing the equalization control may cause the single cell to be over-discharged and damaged. In order to protect the single cell, the equalization control is stopped.

[0068] A second aspect of the present invention provides a battery manager 100, such as Figure 4 As shown, the battery manager 100 includes: at least one processor 1; and a memory 2 communicatively connected to the at least one processor 1.

[0069] The memory 2 stores a computer program that can be executed by at least one processor 1, and the at least one processor executes the computer program to implement the equalization control method of the above embodiment.

[0070] According to the battery manager 100 of the present invention, the processor 1 executes the computer program stored in the memory 2 to realize the equalization control method, which can accurately adjust each individual cell to be more consistent and maximize the capacity of the battery pack.

[0071] A third aspect of the present invention provides a computer storage medium on which a computer program is stored, and when the computer program is executed by a processor, it implements the equalization control method of the above embodiments.

[0072] A fourth aspect of the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the equalization control method described above.

[0073] A fifth aspect of the present invention provides a vehicle 1000, such as Figure 5 As shown, the vehicle 1000 includes the battery manager 100 of the above embodiment.

[0074] According to the vehicle 1000 of the present invention, each individual battery cell can be accurately adjusted to be consistent, thereby maximizing the capacity of the battery pack.

[0075] In the description of this specification, any process or method described in the flowcharts or otherwise herein may be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0076] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0077] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0078] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0079] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0080] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0081] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0082] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An equalization control method, characterized in that, include: Obtain the individual cell voltage of each cell in the battery pack at the charging cutoff time; Determine the actual voltage difference between the individual cell voltage of each cell and the lowest voltage among all cells; The equalization time for each individual cell is determined based on the actual voltage difference corresponding to each individual cell.

2. The equalization control method according to claim 1, characterized in that, The equalization time for each individual cell is determined based on the actual voltage difference corresponding to each individual cell, including: The balanced capacity of each individual cell is determined based on the actual voltage difference corresponding to each individual cell and the rated capacity of the individual cell. The balancing time for each individual cell is determined based on its balancing capacity.

3. The equalization control method according to claim 2, characterized in that, The balanced capacity of each individual cell is determined based on the actual voltage difference corresponding to each individual cell and the rated capacity of the individual cell, including: The actual balanced SOC value of each individual cell is determined by querying the standard correspondence relationship based on the actual voltage difference corresponding to each individual cell. The standard correspondence relationship is the correspondence relationship between the voltage difference and the balanced SOC value established based on the charging voltage-SOC relationship curve of the individual cell. The balanced capacity of each individual cell is determined based on its actual balanced SOC value and the rated capacity.

4. The equalization control method according to claim 3, characterized in that, The standard correspondence includes multiple data point pairs of voltage differences and balanced SOC values. The voltage differences in these data point pairs are discretely distributed. The actual balanced SOC value of each individual cell is determined by querying the standard correspondence based on the actual voltage difference corresponding to each individual cell, including: If the actual voltage difference exists in the data point pair, the actual equalization SOC value is determined by querying the data point pair based on the actual voltage difference. If the actual voltage difference does not exist in the data point pair, the adjacent voltage differences of the actual voltage difference in the data point pair are determined, and the actual equalization SOC value is determined based on the actual voltage difference and the adjacent voltage differences.

5. The equalization control method according to claim 4, characterized in that, The adjacent voltage difference includes a first voltage difference and a second voltage difference. Determining the actual equalization SOC value based on the actual voltage difference and the adjacent voltage differences includes: When the actual voltage difference is greater than the first voltage difference and less than the second voltage difference, a linear model is formed based on the data point pair where the first voltage difference is located and the data point pair where the second voltage difference is located. The actual equilibrium SOC value is determined based on the actual voltage difference and the linear model.

6. The equalization control method according to claim 4, characterized in that, The adjacent voltage difference is either the lowest voltage difference or the highest voltage difference in the data point pair. The actual equalization SOC value is determined based on the actual voltage difference and the adjacent voltage differences, including: When the actual voltage difference is less than the minimum voltage difference, the equalization SOC value corresponding to the minimum voltage difference is taken as the actual equalization SOC value; Alternatively, if the actual voltage difference is greater than the maximum voltage difference, the equalization SOC value corresponding to the maximum voltage difference shall be used as the actual equalization SOC value.

7. The equalization control method according to any one of claims 3-6, characterized in that, The balanced capacity of each individual cell is determined based on its actual balanced SOC value and the rated capacity, including: The product of the actual balanced SOC value and the rated capacity is taken as the balanced capacity.

8. The equalization control method according to claim 2, characterized in that, The balancing time for each individual cell is determined based on its balancing capacity, including: Determine the equalization current value of the individual battery cell; The ratio of the equalization capacity to the equalization current value is used as the equalization duration.

9. The equalization control method according to claim 1, characterized in that, The method further includes: The equalization control of each individual cell is performed according to the equalization time of each individual cell until the individual cell meets the equalization stop condition.

10. The equalization control method according to claim 9, characterized in that, The stopping equilibrium condition includes any of the following: The equalization control time for the individual battery cell reaches the equalization time. The voltage of the individual battery cell is lower than a preset threshold.

11. A battery manager, characterized in that, include: At least one processor; A memory that is communicatively connected to at least one of the processors; The memory stores a computer program that can be executed by at least one of the processors, and when the at least one processor executes the computer program, it implements the equalization control method according to any one of claims 1-10.

12. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the equalization control method according to any one of claims 1-10.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the equalization control method according to any one of claims 1-10.

14. A vehicle, characterized in that, Includes the battery manager as described in claim 11.

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