A method, device and equipment for cell balancing

Abstract

The present invention discloses a cell balancing method, device and equipment. The method includes: obtaining cell information of cells to be balanced, and dividing a plurality of cells to be balanced into a plurality of balancing partitions based on the positions of the collection boards where the respective cells to be balanced are located as represented by the cell information; performing balancing on the cells to be balanced in each balancing partition based on the protection temperature of each balancing partition, where the protection temperature is the temperature upper limit of the balancing partition. The technical solution provided by the present invention divides the cells to be balanced located on different collection boards into different balancing partitions, enabling the cells between different balancing partitions to simultaneously start balancing, enabling multiple balancing partitions to perform balancing work simultaneously without affecting each other, and greatly improving the cell balancing efficiency.

Description

Technical Field

[0001] The present invention relates to the field of new energy battery design, and particularly to a method, device and equipment for cell balancing. Background Art

[0002] In a power battery cluster composed of multiple battery cells connected in series, due to inevitable differences in the manufacturing process of battery cells, and in addition, during the use of the battery cluster, there are also differences in heat dissipation, charging and discharging, etc. of each battery cell, which results in different voltages among the battery cells, that is, the so-called battery cell imbalance phenomenon. If the unbalanced battery pack is not balanced in time, the voltage difference among the battery cells will become larger and larger, resulting in the deterioration of the battery pack performance and the reduction of the service life. Therefore, the balancing of the battery is particularly important. The existing technology usually selects the unbalanced battery cells (i.e., the battery cells with too high voltage) according to the voltage or SOC (State Of Charge) of the battery cells, and then discharges the unbalanced battery cells through a balancing resistor to reach a new balanced state. However, the discharge of the balancing resistor will generate heat. In order to avoid too high temperature in the balancing area during the balancing process, the existing technology adopts the odd-even balancing technology (the odd-numbered battery cells and the even-numbered battery cells are balanced at different times), but the odd-even distinction in balancing is too strict, and it is absolutely not allowed for the odd-numbered battery cells and the even-numbered battery cells to start balancing at the same time. For example, the No. 1 battery cell and the No. 20 battery cell are on two different acquisition boards respectively, and simultaneous balancing will not exceed the protection temperature limit, but the existing technology still divides them into two time periods for balancing, resulting in low balancing efficiency. Therefore, how to improve the cell balancing efficiency without exceeding the protection temperature is an urgent problem to be solved. Summary of the Invention

[0003] In view of this, the embodiments of the present invention provide a method, device and equipment for cell balancing, thereby improving the balancing efficiency of the battery cells in the power battery pack.

[0004] According to a first aspect, the present invention provides a method for cell balancing, the method including: obtaining cell information of the cells to be balanced, and dividing a plurality of cells to be balanced into a plurality of balancing partitions based on the acquisition board positions where the respective cells to be balanced are located as represented by the cell information; balancing the cells to be balanced in each balancing partition based on the protection temperature of each balancing partition, where the protection temperature is the temperature upper limit of the balancing partition.

[0005] Optionally, the dividing a plurality of cells to be balanced into a plurality of balancing partitions based on the acquisition board positions where the respective cells to be balanced are located as represented by the cell information includes: determining the acquisition board positions where the respective cells to be balanced are located based on the cell numbers of the respective cells to be balanced in the cell information; dividing the respective cells to be balanced into the balancing partitions of their respective acquisition boards with one acquisition board as one balancing partition.

[0006] Optionally, equalizing the cells to be equalized in each equalization partition based on the protection temperature of each equalization partition includes: testing and generating the maximum equalization quantity of each equalization partition according to the protection temperature of each equalization partition, where the maximum equalization quantity is used to represent the maximum number of cells that can be simultaneously equalized; performing grouped and time-sharing equalization on the cells to be equalized in each equalization partition based on the maximum equalization quantity of each equalization partition.

[0007] Optionally, performing grouped and time-sharing equalization on the cells to be equalized in each equalization partition based on the maximum equalization quantity of each equalization partition includes: comparing the maximum equalization quantity of the current equalization partition with the number of cells to be equalized in the current equalization partition; if the maximum equalization quantity of the current equalization partition is greater than the number of cells to be equalized in the current equalization partition, performing simultaneous equalization on all the cells to be equalized in the current equalization partition; if the maximum equalization quantity of the current equalization partition is less than the number of cells to be equalized in the current equalization partition, performing grouped and time-sharing equalization on the cells to be equalized in the current equalization partition based on the stacking degree of the cells to be equalized in the current equalization partition, where the stacking degree is used to characterize the distance between cells in space; in each equalization partition, simultaneously executing the step of if the maximum equalization quantity of the current equalization partition is greater than the number of cells to be equalized in the current equalization partition, performing simultaneous equalization on all the cells to be equalized in the current equalization partition, to the step of if the maximum equalization quantity of the current equalization partition is less than the number of cells to be equalized in the current equalization partition, performing grouped and time-sharing equalization on the cells to be equalized in the current equalization partition based on the stacking degree of the cells to be equalized in the current equalization partition, until the cells to be equalized in each equalization partition are equalized.

[0008] Optionally, the step of determining the stacking degree of the cells to be equalized in the current equalization partition includes: initializing the stacking degree to 0 and counting the continuous adjacent situations of the cells to be equalized; adjusting the stacking degree based on the continuous adjacent situations of the cells to be equalized, where substituting the number k1 of independent cells among the cells to be equalized into the formula: stacking degree = stacking degree + k1 × 0 to adjust the stacking degree, and the independent cell is a cell that is not adjacent to any other cell to be equalized; substituting the number k2 of two-cell stacks among the cells to be equalized into the formula: stacking degree = stacking degree + k2 × 1 to adjust the stacking degree, and the two-cell stack is a cell set composed of two adjacent cells to be equalized; substituting the number k3 of n-cell stacks among the cells to be equalized into the formula: stacking degree = stacking degree + k3 × 2 n-2 to adjust the stacking degree, and the n-cell stack is a cell set composed of n continuously adjacent cells to be equalized, and n > 2.

[0009] Optionally, the step of performing grouped time-sharing equalization on the cells to be equalized in the current equalization partition based on the stacking degree of the cells to be equalized in the current equalization partition includes: removing a target cell to be equalized, and determining whether the number of remaining cells to be equalized is greater than the maximum equalization number of the current equalization partition, where the target cell to be equalized is the cell to be equalized removed when the stacking degree of the remaining cells to be equalized is the lowest; if it is greater, then for the currently remaining cells to be equalized, return to the step of removing a target cell to be equalized and determining whether the number of remaining cells to be equalized is greater than the maximum equalization number of the current equalization partition; if it is not greater, then use the remaining cells to be equalized and the removed cell to be equalized as two equalization groups respectively for time-sharing equalization.

[0010] Optionally, the step of using the remaining cells to be equalized and the removed cell to be equalized as two equalization groups respectively for time-sharing equalization includes: equalizing the cells to be equalized in the first equalization group with a first preset time length, where the first equalization group is the equalization group where the remaining cells to be equalized are located; equalizing the cells to be equalized in the second equalization group with a second preset time length, where the second equalization group is the equalization group where the removed cell to be equalized is located; return to the step of comparing the maximum equalization number of the current equalization partition with the number of cells to be equalized in the current equalization partition.

[0011] According to a second aspect, the present invention provides a cell equalization device, where the device includes: an information acquisition module, configured to acquire cell information of cells to be equalized, and divide a plurality of cells to be equalized into a plurality of equalization partitions based on the acquisition board positions where the respective cells to be equalized represented by the cell information are located; an equalization module, configured to equalize the cells to be equalized in each equalization partition based on the protection temperature of each equalization partition, where the protection temperature is the temperature upper limit of the equalization partition.

[0012] According to a third aspect, the present invention provides a cell equalization device, including: a memory and a processor, where the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the method according to the first aspect, or any optional implementation manner of the first aspect.

[0013] According to a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause the computer to execute the method according to the first aspect, or any optional implementation manner of the first aspect.

[0014] The technical solution provided by this application has the following advantages:

[0015] For the technical solution provided by this application, first, the acquisition boards where each cell to be balanced is located are identified according to the cell information of the cells to be balanced. Then, based on the characteristic that the acquisition boards do not interfere with each other, the cells to be balanced located on different acquisition boards are divided into different balancing partitions, so that the cells between different balancing partitions can be balanced simultaneously. Finally, according to the protection temperature of each balancing partition itself, a unified or separate balancing strategy is carried out for the cells to be balanced within the balancing partition. For multiple balancing partitions, the multiple balancing partitions perform balancing operations simultaneously without interfering with each other, greatly improving the cell balancing efficiency.

[0016] In addition, according to the protection temperature of each balancing partition, the maximum number of cells that can be balanced simultaneously (i.e., the highest balancing quantity) supported by each balancing partition can be experimentally measured. Thus, each balancing partition uses the highest balancing quantity as an index to perform time-sharing grouping balancing on the cells to be balanced, further improving the accuracy and safety of balancing. When the number of cells to be balanced within any one balancing partition is not greater than the highest balancing quantity of that partition, all the cells to be balanced can be balanced at one time; since the more consecutive adjacent cells need to be balanced, the worse the heat dissipation of the acquisition board and the longer the balancing time, therefore, taking the stacking degree of the cells as a standard, when the number of cells to be balanced is greater than the maximum number of cells in that partition, the cells to be balanced are divided into two groups. The quantity of one group not only meets the highest balancing quantity for simultaneous activation but also ensures the lowest stacking degree to accelerate heat dissipation. This group is used as the first group to perform balancing first, and the other group performs balancing later, thereby further improving the balancing efficiency. And, the two balancing groups are alternately balanced through a preset time length. After completion, if there are still cells that have not been balanced, they are compared with the maximum balancing quantity of this partition again, and the balancing steps are cyclically executed to ensure the stability and reliability of the overall battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings. The drawings are schematic and should not be construed as imposing any limitation on the present invention. In the drawings:

[0018] Figure 1 The schematic diagram of the steps of a cell balancing method in an embodiment of the present invention is shown;

[0019] Figure 2 The flowchart of a cell balancing method in an embodiment of the present invention is shown;

[0020] Figure 3 The structural diagram of a cell balancing device in an embodiment of the present invention is shown;

[0021] Figure 4 The structural diagram of a cell balancing device in an embodiment of the present invention is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] Please refer to Figure 1 and Figure 2 , in one embodiment, a method for balancing battery cells specifically includes the following steps:

[0024] Step S101: Obtain the cell information of the cells to be balanced, and divide the multiple cells to be balanced into multiple balancing partitions based on the positions of the collection boards where the respective cells to be balanced are located as represented by the cell information.

[0025] Step S102: Balance the cells to be balanced within each balancing partition based on the protection temperature of each balancing partition, where the protection temperature is the temperature upper limit of the balancing partition.

[0026] Specifically, in this embodiment, before balancing the cells, first obtain the cell information of all the cells to be balanced in the battery cluster. The cell information includes, but is not limited to, cell serial number, open-circuit voltage of the cell, cell capacity, cell SOC, and cell temperature. Then, identify the collection board where each cell is located according to the cell serial number, and then divide each cell into multiple balancing partitions based on the collection board, so that the balancing partitions can work independently and perform discharge balancing simultaneously, greatly improving the balancing efficiency. In addition, it can be set according to the actual situation that one balancing partition contains one collection board, two collection boards, etc. The present invention is not limited thereto. Then, conduct experimental tests on each balancing partition to obtain the highest temperature that each balancing partition can withstand, and use the temperature value of the highest temperature as the protection temperature to limit the total temperature of each balancing partition. Finally, under the premise of not exceeding the protection temperature of each balancing partition, perform unified or grouped balancing work.

[0027] Specifically, in one embodiment, the above step S101 specifically includes the following steps:

[0028] Step 1: Determine the positions of the collection boards where the respective cells to be balanced are located based on the cell serial numbers of the respective cells to be balanced in the cell information.

[0029] Step 2: Divide the respective cells to be balanced into the balancing partitions of their respective collection boards with one collection board as one balancing partition.

[0030] Specifically, in this embodiment, after determining the position of the acquisition board where each cell to be balanced is located through the cell serial number, considering the situation that the number of cells to be balanced in one acquisition board may be too large, each cell to be balanced is divided with one acquisition board as one balancing partition, so that more cells can be balanced simultaneously and the reliability is higher.

[0031] Specifically, in one embodiment, step S102 described above specifically includes the following steps:

[0032] Step Three: Generate the maximum balancing quantity of each balancing partition according to the protection temperature test of each balancing partition, and the maximum balancing quantity is used to represent the maximum number of cells that can be balanced simultaneously.

[0033] Step Four: Perform grouped and time-sharing balancing on the cells to be balanced in each balancing partition based on the maximum balancing quantity of each balancing partition.

[0034] Specifically, during the discharge balancing process of the cells, the temperature of the cells will increase to a certain extent. In this embodiment, for each balancing partition, first determine the maximum number of cells that can be balanced simultaneously in one balancing partition based on actual tests as the maximum balancing quantity of this balancing area. Ensure that when the cells with the maximum number in one acquisition board are balanced simultaneously, the temperature in this area will not continue to rise and exceed the protection temperature, resulting in the suspension of balancing. Subsequently, use the maximum balancing quantity as the balancing index to perform grouped and time-sharing balancing on the cells to be balanced in each balancing partition, so that the standard for measuring the balancing status is clearer and more accurate, further improving the balancing efficiency and accuracy, and ensuring the reliability of the balancing method.

[0035] Specifically, in one embodiment, step Four described above specifically includes the following steps:

[0036] Step Five: Compare the maximum balancing quantity of the current balancing partition with the number of cells to be balanced in the current balancing partition.

[0037] Step Six: If the maximum balancing quantity of the current balancing partition is greater than the number of cells to be balanced in the current balancing partition, perform simultaneous balancing on all the cells to be balanced in the current balancing partition.

[0038] Step Seven: If the maximum balancing quantity of the current balancing partition is less than the number of cells to be balanced in the current balancing partition, perform grouped and time-sharing balancing on the cells to be balanced in the current balancing partition based on the stacking degree of the cells to be balanced in the current balancing partition, and the stacking degree is used to characterize the distance between cells in space.

[0039] Step 8: In each equalization partition, simultaneously execute the steps from if the highest equalization quantity in the current equalization partition is greater than the number of cells to be equalized in the current equalization partition, then simultaneously equalize all the cells to be equalized in the current equalization partition, to if the highest equalization quantity in the current equalization partition is less than the number of cells to be equalized in the current equalization partition, then perform grouped time-sharing equalization on the cells to be equalized in the current equalization partition based on the stacking degree of the cells to be equalized in the current equalization partition, until the cells to be equalized in each equalization partition are equalized.

[0040] Specifically, before starting the equalization for any one equalization partition, first determine whether the total number of cells to be equalized in this partition exceeds the highest equalization quantity. If it does not exceed, it indicates that all the cells in this equalization partition start equalization simultaneously, and the temperature of this acquisition board will not rise to exceed the protection temperature. Thus, it is possible to simultaneously equalize all the cells under the premise of safety and without shutting down the machine, improving the equalization efficiency. If the total number of cells to be equalized in this partition exceeds the highest equalization quantity, then it is necessary to group the cells to be equalized in this partition for equalization at different time intervals. To ensure the highest grouping efficiency, in this embodiment, grouped time-sharing equalization is performed on the cells to be equalized in the current equalization partition based on the stacking degree of the cells to be equalized in the current equalization partition. When the cells are closer and stacked more, it will cause worse heat dissipation of the acquisition board. When the same number of cells are equalized, the closer the cells are aggregated, the longer the corresponding equalization time will be. Therefore, group the cells to be equalized based on the stacking degree, making the stacking degree of each group as low as possible, thereby further improving the equalization efficiency of the cells. Finally, for each equalization partition, simultaneously perform Step 6 and Step 7, ensuring that the number of cells starting equalization simultaneously is the largest, making the equalization efficiency of the cells the highest and the time the shortest. Compared with the prior art, the equalization efficiency of the cells is greatly improved.

[0041] Specifically, in one embodiment, the method for determining the stacking degree in the above steps specifically includes the following steps:

[0042] Step 9: Initialize the stacking degree to 0 and count the continuous adjacent situations of the cells to be equalized.

[0043] Step 10: Adjust the stacking degree based on the continuous adjacent situations of the cells to be equalized, where:

[0044] 1. Substitute the number k1 of independent cells among the cells to be equalized into the formula: stacking degree = stacking degree + k1×0, and adjust the stacking degree. An independent cell is a cell that is not adjacent to any other cell to be equalized;

[0045] 2. Substitute the number k2 of two stacks of cells in the cells to be balanced into the formula: stacking degree = stacking degree + k2 × 1 to adjust the stacking degree. The two stacks of cells are a set of cells composed of two adjacent cells to be balanced;

[0046] 3. Substitute the number k3 of n stacks of cells in the cells to be balanced into the formula: stacking degree = stacking degree + k3 × 2 n-2 , to adjust the stacking degree. The n stacks of cells are a set of cells composed of n continuously adjacent cells to be balanced.

[0047] Specifically, in this embodiment, if the cell to be balanced is an independent cell that is not adjacent to any other cell to be balanced, it is regarded that the stacking degree increment of this cell is 0, that is, this cell has no stacking; if there are two cells to be balanced that are adjacent, and these two cells are no longer adjacent to any other cell to be balanced, then these two cells are regarded as forming a two-stack cell, and the corresponding stacking degree increment of the two-stack cell is 1; if there are n cells to be balanced that are adjacent (n>2), and these n cells are no longer adjacent to any other cell to be balanced, then these n cells are regarded as forming an n-stack cell, and the corresponding stacking degree increment of the n-stack cell is 2 n-2 . Combining with the heat diffusion theory, set the mapping relationship between the stacking increment and the number of continuously adjacent cells of the cell, so that the influence of the stacking degree on the equalization time basically conforms to the natural law. Thereby further improving the accuracy of grouping during the equalization process and improving the equalization efficiency. For example: for the acquisition board 1, confirm that the serial numbers of the cells to be balanced that need to be turned on on this acquisition board include 1, 2, 3, 5, 7, 8, 9, 10, 12, 13, and calculate its stacking degree: 1, 2, 3 are one stack, 5 is one stack, 7, 8, 9, 10 are one stack, 12, 13 are one stack, then the stacking degree of the balanced cells corresponding to this partition is 2 + 0 + 4 + 1 = 7.

[0048] Specifically, in one embodiment, step seven above specifically includes the following steps:

[0049] Step eleven: Eliminate a target cell to be balanced, and judge whether the number of remaining cells to be balanced is greater than the highest equalization number of the current equalization partition. The target cell to be balanced is the cell to be balanced corresponding to the lowest stacking degree of the remaining cells to be balanced.

[0050] Step twelve: If it is greater, then for the current remaining cells to be balanced, return to the step of eliminating a target cell to be balanced and judging whether the number of remaining cells to be balanced is greater than the highest equalization number of the current equalization partition.

[0051] Step thirteen: If it is not greater, then use the remaining cells to be balanced and the eliminated cells to be balanced as two equalization groups for time-sharing equalization.

[0052] Specifically, when the number of cells to be balanced in a balanced partition is greater than the maximum balancing number, the cells to be balanced in this balanced partition need to be grouped and balanced at different times. In this embodiment, a scheme of dividing into two groups is adopted. First, one cell to be balanced is removed from all the cells to be balanced, and then it is judged whether the remaining cells exceed the maximum balancing number. If they still exceed, another cell is removed until the number of remaining cells to be balanced is equal to the maximum balancing number. Moreover, each time a cell to be balanced is removed, the stacking degree of the remaining cells after each cell to be balanced is removed is calculated traversally, and then the remaining cell to be balanced with the lowest stacking degree is found. At this time, the corresponding cell to be balanced removed is the target cell to be balanced removed in the actual grouping process, so that the stacking degree of the remaining cells to be balanced can be minimized, the heat dissipation effect can be the best, and the balancing time can be the shortest, that is, the balancing efficiency is the highest. Then, the remaining cells to be balanced are divided into one group, and the removed cells to be balanced are divided into one group, and the above two groups of cells are discharged and balanced at different time periods. In this embodiment, usually the number of the remaining cells to be balanced is the larger group, so the remaining cells to be balanced are balanced first, so that the number of cells with balancing enabled at the same time is the largest, and then the removed cells to be balanced are balanced, thereby improving the balancing efficiency.

[0053] Specifically, in one embodiment, step thirteen specifically includes the following steps:

[0054] Step fourteen: Balance the cells to be balanced in the first balanced group at the first preset time length, and the first balanced group is the balanced group where the remaining cells to be balanced are located.

[0055] Step fifteen: Balance the cells to be balanced in the second balanced group at the second preset time length, and the second balanced group is the balanced group where the removed cells to be balanced are located.

[0056] Step sixteen: Return to step five.

[0057] Specifically, in this embodiment, considering that if all the battery cells in the first equalization group are equalized and then the second equalization group starts to be equalized, it is very likely that the waiting time of the second equalization group will be too long, and the voltage difference of its battery cells will be higher, resulting in potential safety hazards. Therefore, it is necessary to alternately equalize the two equalization groups within a preset time. In this embodiment, the first equalization group is equalized for the first preset time length. Usually, when the first preset time length ends, there are still some battery cells in the first equalization group that have not been equalized. However, to ensure the reliability of the battery cluster, it is necessary to suspend the equalization of the first equalization group and start to equalize the second equalization group, and the equalization time length is the second preset time length. Herein, the first preset time length and the second preset time length are safety times to ensure that no abnormalities occur in the two groups of battery cells, and currently, a large number of experiments are used to judge based on expert experience. After that, after the first preset time length and the second preset time length end, return to step five to re-determine whether the maximum equalization quantity is greater than the number of battery cells to be equalized in the current equalization partition. If there are no battery cells to be equalized in the current equalization partition, the equalization work of the current equalization partition is ended; if there are still battery cells to be equalized in the current equalization partition that have not been equalized, but the number thereof is not greater than the maximum equalization quantity, they can be directly equalized without grouping; if there are still battery cells to be equalized in the current equalization partition that have not been equalized, and the number thereof is greater than the maximum equalization quantity, then continue to re-group and equalize according to the method from step eleven to step thirteen to ensure that the number of battery cells that start to be equalized simultaneously after the new grouping is the largest and the equalization efficiency is the highest. After each cycle, the equalization time pre-calculated through the discharge current and the differential voltage is updated and displayed to the user, so as to facilitate the user to timely know the latest remaining equalization time.

[0058] Through the above steps, the technical solution provided by the present application first identifies the acquisition board where each battery cell to be equalized is located according to the battery cell information of the battery cells to be equalized, and then based on the characteristic that the acquisition boards do not interfere with each other, divides the battery cells to be equalized located on different acquisition boards into different equalization partitions, so that the battery cells between different equalization partitions can start to be equalized simultaneously. Finally, according to the protection temperature of each equalization partition itself, a unified or separate equalization strategy is adopted for the battery cells to be equalized in the equalization partition. For multiple equalization partitions, the multiple equalization partitions perform equalization work simultaneously without interference, greatly improving the equalization efficiency of the battery cells.

[0059] In addition, according to the protection temperature of each equalization partition, the maximum number of battery cells that can support simultaneous equalization in each equalization partition (i.e., the highest equalization quantity) can be experimentally measured. Thus, each equalization partition uses the highest equalization quantity as an index to perform time-sharing grouped equalization on the battery cells to be equalized, further improving the accuracy and safety of equalization. When the number of battery cells to be equalized in any equalization partition is not greater than the highest equalization quantity of that partition, all the battery cells to be equalized can be equalized at once. Since the more continuously adjacent battery cells need to be equalized, the worse the heat dissipation of the acquisition board and the longer the equalization time. Therefore, based on the stacking degree of the battery cells, when the number of battery cells to be equalized is greater than the maximum number of battery cells in that partition, the battery cells to be equalized are divided into two groups. The quantity of one group not only meets the highest equalization quantity for simultaneous activation but also ensures the lowest stacking degree to accelerate heat dissipation. This group is used as the first group to perform equalization first, and the other group performs equalization later, thereby further improving the equalization efficiency. Moreover, the two equalization groups are alternately equalized through a preset time length. After completion, if there are still battery cells that have not been fully equalized, they are compared with the maximum equalization quantity of that partition again, and the equalization steps are cyclically executed, ensuring the stability and reliability of the overall battery pack.

[0060] As Figure 3 shown, this embodiment also provides a battery cell equalization device, which includes:

[0061] An information acquisition module 101, configured to obtain the battery cell information of the battery cells to be equalized, and divide a plurality of battery cells to be equalized into a plurality of equalization partitions based on the positions of the acquisition boards where the battery cells to be equalized are located according to the battery cell information. For detailed content, refer to the relevant description of step S101 in the above method embodiment, and details will not be elaborated here.

[0062] An equalization module 102, configured to equalize the battery cells to be equalized in each equalization partition based on the protection temperature of each equalization partition, where the protection temperature is the temperature upper limit of the equalization partition. For detailed content, refer to the relevant description of step S102 in the above method embodiment, and details will not be elaborated here.

[0063] A battery cell equalization device provided by an embodiment of the present invention is used to execute a battery cell equalization method provided by the above embodiment. Its implementation manner and principle are the same. For detailed content, refer to the relevant description of the above method embodiment, and details will not be elaborated here.

[0064] Through the collaborative cooperation of the above-mentioned various components, the technical solution provided by this application first identifies the acquisition boards where each cell to be balanced is located based on the cell information of the cells to be balanced. Then, based on the characteristic that the acquisition boards do not interfere with each other, the cells to be balanced located on different acquisition boards are divided into different balancing partitions, so that the cells between different balancing partitions can be balanced simultaneously. Finally, according to the protection temperature of each balancing partition itself, a unified or separate balancing strategy is carried out for the cells to be balanced within the balancing partition. For multiple balancing partitions, the multiple balancing partitions perform balancing work simultaneously without affecting each other, greatly improving the cell balancing efficiency.

[0065] In addition, according to the protection temperature of each balancing partition, the maximum number of cells that can be balanced simultaneously (i.e., the highest balancing quantity) supported by each balancing partition can be measured through experiments. Thus, each balancing partition uses the highest balancing quantity as an index to perform time-sharing grouping balancing on the cells to be balanced, further improving the accuracy and safety of balancing. When the number of cells to be balanced within any one balancing partition is not greater than the highest balancing quantity of this partition, all the cells to be balanced can be balanced at one time; since the more consecutive adjacent cells need to be balanced, the worse the heat dissipation of the acquisition board and the longer the balancing time, therefore, taking the stacking degree of the cells as a standard, when the number of cells to be balanced is greater than the maximum number of cells in this partition, the cells to be balanced are divided into two groups. The number of one group not only meets the highest balancing quantity that can be started simultaneously but also can ensure the lowest stacking degree to accelerate heat dissipation. This group is used as the first group to perform balancing first, and the other group performs balancing later, thereby further improving the balancing efficiency. And, through a preset time length, the two balancing groups are alternately balanced. After the end, if there are still cells that have not been balanced, they are compared with the maximum balancing quantity of this partition again, and the balancing steps are cyclically executed to ensure the stability and reliability of the overall battery pack.

[0066] Figure 4 FIG. shows a cell balancing device according to an embodiment of the present invention. The device includes a processor 901 and a memory 902, which can be connected through a bus or other means. Figure 4 Taking the connection through the bus as an example.

[0067] The processor 901 may be a Central Processing Unit (CPU). The processor 901 may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. chips, or combinations of the above types of chips.

[0068] As a non-transitory computer-readable storage medium, the memory 902 can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the above method embodiments. The processor 901 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions, and modules stored in the memory 902, that is, implements the methods in the above method embodiments.

[0069] The memory 902 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created by the processor 901, etc. In addition, the memory 902 may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory 902 may optionally include a memory remotely set relative to the processor 901, and these remote memories can be connected to the processor 901 through a network. Examples of the above networks include but are not limited to the Internet, enterprise intranets, local area networks, mobile communication networks, and combinations thereof.

[0070] One or more modules are stored in the memory 902 and, when executed by the processor 901, implement the methods in the above method embodiments.

[0071] Specific details of the above battery cell equalization device can be understood by referring to the corresponding related descriptions and effects in the above method embodiments, and will not be elaborated here.

[0072] Those skilled in the art can understand that to implement all or part of the processes in the above-described embodiment methods, it can be completed by instructing relevant hardware through a computer program. The implemented program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-described method embodiments. Among them, the storage medium can be a magnetic disk, an optical disc, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above-mentioned types of memories.

[0073] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cell balancing method, characterized in that, The method includes: Obtaining the cell information of the cells to be balanced, and dividing a plurality of cells to be balanced into a plurality of balancing partitions based on the positions of the collecting boards where the cells to be balanced are located as characterized by the cell information; Generating the maximum balancing quantity of each balancing partition according to the protection temperature test of each balancing partition, where the maximum balancing quantity is used to represent the maximum number of cells that can be simultaneously balanced, and the protection temperature is the upper temperature limit of the balancing partition; Comparing the maximum balancing quantity of the current balancing partition with the number of cells to be balanced in the current balancing partition; If the maximum balancing quantity of the current balancing partition is less than the number of cells to be balanced in the current balancing partition, then determine the stacking degree of the cells to be balanced in the current balancing partition through the following steps: Initialize the stacking degree to 0; Obtain the number k1 of independent cells among the cells to be balanced, and calculate: stacking degree = stacking degree + k1 × 0, where an independent cell is a cell that is not adjacent to any other cell to be balanced; Obtain the number k2 of two-cell stacks among the cells to be balanced, and calculate: stacking degree = stacking degree + k2 × 1, where a two-cell stack is a cell set composed of two adjacent cells to be balanced; Obtain the number of cells k3 in n stacks of cells to be balanced, and calculate: Stacking degree = Stacking degree + k3 × 2 n-2 , where the n stacks of cells are a cell set composed of n continuously adjacent cells to be balanced, and n > 2; Perform grouped time-sharing balancing on the cells to be balanced in the current balancing partition based on the stacking degree of the cells to be balanced in the current balancing partition. The stacking degree is used to characterize the distance between cells in space. Specifically, divide all the cells to be balanced into two groups based on the stacking degree, and make the stacking degree of each group the lowest.

2. The method according to claim 1, characterized in that, The step of dividing a plurality of cells to be balanced into a plurality of balancing partitions based on the positions of the collecting boards where the cells to be balanced are located as characterized by the cell information includes: Determining the positions of the collecting boards where the cells to be balanced are located based on the cell numbers of the cells to be balanced in the cell information; Taking one collecting board as one balancing partition, and dividing each cell to be balanced into the balancing partition of the collecting board where it is located.

3. The method according to claim 1, characterized in that, The method further includes: If the maximum balancing quantity of the current balancing partition is greater than the number of cells to be balanced in the current balancing partition, then perform simultaneous balancing on all the cells to be balanced in the current balancing partition; In each balancing partition, simultaneously execute the step of if the maximum balancing quantity of the current balancing partition is greater than the number of cells to be balanced in the current balancing partition, then perform simultaneous balancing on all the cells to be balanced in the current balancing partition, and the step of if the maximum balancing quantity of the current balancing partition is less than the number of cells to be balanced in the current balancing partition, then perform grouped time-sharing balancing on the cells to be balanced in the current balancing partition based on the stacking degree of the cells to be balanced in the current balancing partition, until the cells to be balanced in each balancing partition are balanced.

4. The method according to claim 3, wherein, The step of performing grouped time-sharing balancing on the cells to be balanced in the current balancing partition based on the stacking degree of the cells to be balanced in the current balancing partition includes: Eliminating a target cell to be balanced, and determining whether the number of remaining cells to be balanced is greater than the maximum balancing quantity of the current balancing partition. The target cell to be balanced is the cell to be balanced corresponding to the lowest stacking degree of the remaining cells to be balanced. If it is greater, return the step of removing one target cell to be balanced for the currently remaining cells to be balanced, and determine whether the number of remaining cells to be balanced is greater than the maximum balancing number of the current balancing partition; If it is not greater, the remaining cells to be balanced and the removed cells to be balanced are respectively used as two balancing groups for time-sharing balancing.

5. The method according to claim 4, characterized in that The using the remaining cells to be balanced and the removed cells to be balanced as two balancing groups for time-sharing balancing respectively includes: Balancing the cells to be balanced in the first balancing group with a first preset time length, where the first balancing group is the balancing group where the remaining cells to be balanced are located; Balancing the cells to be balanced in the second balancing group with a second preset time length, where the second balancing group is the balancing group where the removed cells to be balanced are located; Return the step of comparing the maximum balancing number of the current balancing partition with the number of cells to be balanced in the current balancing partition.

6. A battery cell equalization device, characterized in that, The device includes: An information acquisition module, configured to acquire cell information of cells to be balanced, and divide a plurality of cells to be balanced into a plurality of balancing partitions based on the positions of the acquisition boards where the respective cells to be balanced characterized by the cell information are located; The balancing module is used to generate the maximum balancing quantity of each balancing zone according to the protection temperature test of each balancing zone. The maximum balancing quantity is used to represent the maximum number of battery cells that can be balanced simultaneously, and the protection temperature is the upper temperature limit of the balancing zone. Compare the maximum balancing quantity of the current balancing zone with the number of battery cells to be balanced in the current balancing zone. If the maximum balancing quantity of the current balancing zone is less than the number of battery cells to be balanced in the current balancing zone, then determine the stacking degree of the battery cells to be balanced in the current balancing zone through the following steps: Initialize the stacking degree to 0; Obtain the number k1 of independent battery cells among the battery cells to be balanced, and calculate: stacking degree = stacking degree + k1×0, where an independent battery cell is a battery cell that is not adjacent to any other battery cells to be balanced; Obtain the number k2 of two-cell stacks among the battery cells to be balanced, and calculate: stacking degree = stacking degree + k2×1, where a two-cell stack is a battery cell set composed of two adjacent battery cells to be balanced; Obtain the number k3 of n-cell stacks among the battery cells to be balanced, and calculate: stacking degree = stacking degree + k3×2 n-2 , where an n-cell stack is a battery cell set composed of n continuously adjacent battery cells to be balanced, and n>2; Perform grouped time-sharing balancing on the battery cells to be balanced in the current balancing zone based on the stacking degree of the battery cells to be balanced in the current balancing zone. The stacking degree is used to characterize the distance between battery cells in space. Among them, divide each battery cell to be balanced into two groups based on the stacking degree, and make the stacking degree of each group the lowest.

7. A cell equalization device, characterized in that, including: A memory and a processor, where the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the method according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause the computer to execute the method according to any one of claims 1-5.

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