Balancing method and device for battery cells of battery pack and battery system

Abstract

The invention provides a battery cell equalization method, device and system, and the method comprises the steps: detecting the voltage values of a plurality of cells of a battery pack, so as to judge whether there is a cell needing to be equalized, and the voltage value of the cell needing to be equalized is higher than a preset equalization target voltage; if yes, continuously numbering the battery cells needing to be balanced again; in the odd channel equalization opening time period, discharging equalization is carried out on the battery cells which are in odd numbers after continuous re-numbering; and in the even channel equalization starting time period, carrying out discharge equalization on the battery cells which are continuously numbered again and are in an even number. According to the technical scheme, the detected voltage needing to be balanced is continuously numbered again, odd-even grouping balancing is carried out based on the continuous numbering again, odd-even distribution is more uniform, and heating is more uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of battery balancing, and in particular to a battery pack cell balancing method and device, and a battery system. Background Art

[0002] For batteries, battery packs are generally composed of multiple strings of cells, such as 16 strings of cells. Due to the deviation in the production process of each string of cells, there may be an imbalance in charging and discharging during use; or even if the initial voltage is consistent in actual use, some cells may have high voltages and some may have low voltages during use, that is, there will be an imbalance between the cells. When there is an imbalance between the cells, the battery pack will lose balance. The unbalanced battery pack cannot be fully charged or fully discharged. The imbalance will also cause the battery to age faster, which not only reduces the battery performance, but also shortens the battery life.

[0003] Therefore, the batteries need to be balanced. Traditional balancing technology usually uses odd-even grouping based on physical numbers to start balancing in turn. However, the cells that need to be balanced are not necessarily distributed in an even-odd distribution based on physical numbers. There will be an obvious problem of uneven distribution of odd-even numbers, which will lead to uneven heating of the battery pack caused by discharge during odd-even balancing, which will in turn cause local overheating of the battery pack and have an adverse effect on the battery. Summary of the invention

[0004] The present invention provides a battery pack cell balancing method and device, and a battery system, so as to solve the problem of uneven heating of a battery pack caused by uneven odd and even distribution in the prior art.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] According to a first aspect of the present invention, a battery pack cell balancing method is provided, comprising:

[0007] Detecting the voltage values ​​of multiple cells of the battery pack to determine whether there are cells that need to be balanced, wherein the cells that need to be balanced are cells whose voltage values ​​are higher than a preset balanced target voltage;

[0008] When there are cells that need to be balanced, the cells that need to be balanced are renumbered consecutively;

[0009] During the odd channel balancing start time period, the cells that are numbered odd after being renumbered are discharged and balanced; during the even channel balancing start time period, the cells that are numbered even after being renumbered are discharged and balanced.

[0010] Optionally, the method further includes: detecting voltage values ​​of a plurality of battery cells of the battery pack in real time to determine whether voltage values ​​of the battery cells that need to be balanced have changed.

[0011] Optionally, the step of re-numbering the cells that need to be balanced consecutively specifically includes:

[0012] The battery cells that need voltage equalization are renumbered consecutively according to the physical numbers of the battery cells.

[0013] Optionally, the physical numbering of the battery cells is specifically:

[0014] According to the physical number of the battery cells in ascending order; or,

[0015] In order of the physical numbers of the cells from largest to smallest.

[0016] Optionally, the odd channel start time period and the even channel balanced start time period are staggered.

[0017] Optionally, the odd channel start time period is consistent with the time length of the adjacent even channel balanced start time period.

[0018] According to a second aspect of the present invention, there is provided a battery pack cell balancing device, comprising:

[0019] A cell voltage detection unit, used to detect the voltage values ​​of multiple cells of the battery;

[0020] a balancing judgment unit, configured to judge whether there are any cells that need balancing based on the voltage value of the cell detected by the cell voltage unit, wherein the cell that needs balancing is a cell whose voltage value is higher than a preset balancing target voltage;

[0021] a re-numbering unit, configured to re-number the cells that need to be balanced continuously when the balancing judgment unit determines that the cells are yes;

[0022] The discharge balancing unit is used to perform discharge balancing on the cells that are numbered odd after being renumbered consecutively during the odd channel balancing opening time period; and to perform discharge balancing on the cells that are numbered even after being renumbered consecutively during the even channel balancing opening time period.

[0023] According to a third aspect of the present invention, there is provided a battery system comprising:

[0024] A battery pack, the battery pack comprising a plurality of battery cells;

[0025] The battery pack cell balancing device is used to balance the voltages of a plurality of battery cells; the battery pack cell balancing device is the battery pack cell balancing device described above.

[0026] According to a fourth aspect of the present invention, there is provided an electronic device, comprising:

[0027] processor;

[0028] and, a memory for storing processor-executable instructions;

[0029] The processor implements the steps in the above method by running the executable instructions.

[0030] According to a fifth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps in the above-described method when executed by a processor.

[0031] The battery pack cell balancing method and device, and the battery system provided by the present invention re-number the cells to be balanced continuously, and perform parity grouping based on the re-numbered numbers to achieve balance, so that the parity distribution is more uniform and the heat generation during the discharge balancing process is also more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 A schematic diagram of balanced discharge according to an example of the prior art;

[0034] Figure 2 A flowchart of a battery cell balancing method according to an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of balanced discharge according to an example of the present invention;

[0036] Figure 4 A schematic diagram of a battery cell balancing device according to an embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of an electronic device according to an embodiment of the present invention;

[0038] Description of reference numerals:

[0039] 11-Battery cell voltage detection unit,

[0040] 12-Balance judgment unit,

[0041] 13- Renumber the units consecutively,

[0042] 14-discharge equalization unit;

[0043] 21- Processor,

[0044] 22-internal bus,

[0045] 23- Network interface,

[0046] 24-Memory,

[0047] 25-Memory. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In the description of the specification of the present invention, it is necessary to understand that the orientation or position relationship indicated by the terms "upper part", "lower part", "upper end", "lower end", "lower surface", "upper surface", etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0050] In the description of the present specification, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0051] In the description of the present invention, "plurality" means a plurality, such as two, three, four, etc., unless otherwise clearly and specifically defined.

[0052] In the description of the present invention, unless otherwise clearly specified and limited, the term "connection" and other terms should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0054] Existing balancing technology usually uses physical numbers to group odd and even numbers to start balancing in turn. The following example uses a 16-string battery pack as an example. Please refer to Figure 1 . Among them, taking the cells that need to be balanced as the physical numbers 1, 2, 3, 5, 6, 7 as an example, then during the time period when the odd channel is balanced, only the cells with the physical numbers odd (i.e. 1, 3, 5, 7) are discharged to achieve the purpose of balance; during the time period when the even channel is balanced, only the cells with the physical numbers even (i.e. 2, 4) are discharged to achieve the purpose of balance. From the above analysis, it can be seen that the odd channel has four cells, while the even channel has only two cells, and there is obvious unevenness. The above is just an example of the cells with physical numbers 1, 2, 3, 5, 6, 7 that need to be balanced. When the cells that need to be balanced are different, the unevenness may be more obvious. Although sometimes there will be a relatively uniform situation, such as the cells with physical numbers 3, 4, 5, 6 need to be balanced, this situation is only an accidental event. In most cases, the odd and even distribution is uneven.

[0055] In view of this, in one embodiment of the present invention, a battery pack cell balancing method is provided. Figure 2 , which includes:

[0056] S11: detecting voltage values ​​of multiple cells of the battery pack to determine whether there are cells that need to be balanced, wherein the cells that need to be balanced are cells whose voltage values ​​are higher than a preset balanced target voltage;

[0057] S12: When there are cells that need to be balanced, the cells that need to be balanced are renumbered consecutively;

[0058] S13: During the odd channel balancing start time period, discharge balancing is performed on the cells that are numbered odd after being renumbered consecutively; during the even channel balancing start time period, discharge balancing is performed on the cells that are numbered even after being renumbered consecutively.

[0059] By adopting the battery pack cell balancing method of the above embodiment, whether the number of cells to be balanced is an even number or an odd number, the odd-even grouping and balancing are relatively uniform after re-numbering continuously. If the number of cells to be balanced is an even number, taking 6 in the above example, then re-numbering continuously and performing odd-even grouping, the number of cells in the odd channel and the even channel are both 3, which are the same; if the number of cells to be balanced is an odd number, taking 7 as an example, then re-numbering continuously and performing odd-even grouping, the number of cells in the odd channel is 4, and the number of cells in the even channel is 3, which only differs by 1. From the above analysis, it can be seen that regardless of whether the number of cells to be balanced is an even number or an odd number, the number of cells in the odd channel and the even channel differs by at most 1, and there will not be a situation where the difference between the two is more than two as in the prior art. Therefore, compared with the prior art, the odd-even distribution is more uniform.

[0060] In one embodiment, after S12, the following step further includes: real-time detection of the voltage values ​​of the plurality of cells of the battery pack to determine whether the cells that need to be balanced have changed. If there are changes, the cells that need to be balanced can be renumbered consecutively. During the real-time voltage value detection process, the voltage of some previously balanced cells may be lower than the preset balanced target voltage and no longer need to be balanced; and the voltage of other unbalanced cells may be higher than the preset balanced target voltage and need to be balanced.

[0061] In one embodiment, the cells that need voltage equalization are renumbered consecutively in S12, which can be: the cells that need voltage equalization are renumbered consecutively according to the physical numbers of the cells. Renumbering consecutively according to the physical numbers is more convenient and quick, and can prevent missing numbers.

[0062] Practically, the cells are renumbered consecutively according to their physical numbers, and the cells can be renumbered consecutively according to the order of their physical numbers.

[0063] As an implementation method, according to the physical numbering order of the battery cells, it can be: according to the order of the physical numbers of the battery cells from small to large. For example, taking the battery cells with physical numbers 1, 2, 3, 5, 6, and 7 that need to be balanced as an example, according to the above order from small to large, they can be renumbered successively as ①, ②, ③, ④, ⑤, ⑥; that is, the physical number 1 is renumbered successively as ①, the physical number 2 is renumbered successively as ②, the physical number 3 is renumbered successively as ③, the physical number 5 is renumbered successively as ④..., and so on; the corresponding list is as follows:

[0064] 1 ① 2 ② 3 ③ 5 ④ 6 ⑤ 7 ⑥

[0065] As another implementation, according to the physical numbering order of the battery cells, it can also be: according to the order of the physical numbers of the battery cells from large to small. For example, taking the battery cells with physical numbers 1, 2, 3, 5, 6, and 7 as an example, they need to be balanced. According to the above order from small to large, they can be renumbered successively as ①, ②, ③, ④, ⑤, ⑥; that is, the physical number 7 is renumbered successively as ①, the physical number 6 is renumbered successively as ②, the physical number 5 is renumbered successively as ③, the physical number 3 is renumbered successively as ④..., and so on. The corresponding list is as follows:

[0066] 7 ① 6 ② 5 ③ 3 ④ 2 ⑤ 1 ⑥

[0067] In different embodiments, the renumbering may be performed in accordance with the physical number or not in the order of the physical number, but may be performed randomly. For example, taking the above-mentioned cells with physical numbers 1, 2, 3, 5, 6, and 7 that need to be balanced as an example, the cell with physical number 3 may be renumbered continuously as ①, the cell with physical number 1 may be renumbered continuously as ②, the cell with physical number 5 may be renumbered continuously as ③, the cell with physical number 6 may be renumbered continuously as ④… That is, it is not performed in the order of the physical number, but randomly, as long as the cells with physical numbers 1, 2, 3, 5, 6, and 7 are all renumbered continuously.

[0068] Of course, in different embodiments, the renumbering may not be performed in the order of physical numbering, and other parameters of the battery cells may be used as marks for numbering. For example, the renumbering may be performed according to the voltage value, such as renumbering the battery cells that need to be balanced in the order of voltage value from large to small, or renumbering may be performed in the order of voltage value from small to large.

[0069] It should be understood that the above examples are all based on renumbering from ①. In different embodiments, it does not necessarily start from ①, it can also start from ②, that is, it can start from any value. As long as it is a continuous number, the parity distribution is uniform or differs by 1.

[0070] It is feasible to stagger the odd channel start time period with the even channel balanced start time period, please refer to Figure 3 .

[0071] In practice, for the convenience of management, the length of the odd channel equalization start time period is consistent with the length of the adjacent even channel equalization start time period.

[0072] Furthermore, all odd channel equalization-on time periods may be set to be consistent with the even channel equalization-on time periods.

[0073] In different embodiments, not all odd channel balancing on time periods may be consistent with even channel balancing on time periods. When the voltage value of the battery cell that needs to be balanced is relatively high (it may be when the balancing is just started), the odd channel balancing on time period and the even channel balancing on time period may be set to be longer. When the voltage value of the battery cell that needs to be balanced is relatively low (it may be after a period of balancing), the odd channel balancing on time period and the even channel balancing on time period may be set to be shorter.

[0074] Of course, in different embodiments, the length of the odd channel start time period and the adjacent even channel opening time period may be inconsistent. When renumbering continuously, the voltage values ​​may be grouped into one group (odd or even) and the lower voltage values ​​may be grouped into one group (even or odd) according to the voltage value. In this way, the channel opening time period may be set according to the distance between the voltage value of the battery cell and the preset balanced target voltage. For example, when a group with a higher voltage value is grouped into an odd group, the odd channel opening time may be set to be longer.

[0075] In one embodiment, a battery pack cell balancing device is provided, please refer to Figure 4 , which includes:

[0076] A cell voltage detection unit 11 is used to detect the voltage values ​​of multiple cells of the battery;

[0077] The equalization judgment unit 12 is used to judge whether there are cells that need to be equalized based on the voltage value of the cell detected by the cell voltage unit, wherein the cell that needs to be equalized is a cell whose voltage value is higher than a preset equalization target voltage;

[0078] A re-numbering unit 13 is used to re-number the cells that need to be balanced continuously when the equalization judgment unit judges that it is yes;

[0079] The discharge balancing unit 14 is used to perform discharge balancing on the cells that are numbered odd after being renumbered consecutively during the odd channel balancing start time period; and to perform discharge balancing on the cells that are numbered even after being renumbered consecutively during the even channel balancing start time period.

[0080] In one embodiment, the cell voltage detection unit is further used to detect the voltage values ​​of the multiple cells of the battery pack in real time to see if there are any changes in the cells that need to be balanced; if there are any changes, the cells that need to be balanced are renumbered consecutively.

[0081] In one embodiment, the re-serial numbering unit 13 may be specifically configured to re-serialize the battery cells that require voltage equalization according to the physical numbering sequence of the battery cells.

[0082] In one embodiment, the odd channel equalization start time period in the discharge equalization unit 14 may be consistent with the time length of the adjacent even channel equalization start time period.

[0083] In one embodiment, a battery system is provided, comprising:

[0084] A battery pack, wherein the battery pack includes a plurality of battery cells;

[0085] The battery pack cell balancing device is used to balance the voltages of a plurality of battery cells; the battery pack cell balancing device is the battery pack cell balancing device described in the above embodiment.

[0086] In one embodiment, an electronic device is also provided, please refer to Figure 5 . At the hardware level, the device includes a processor 21, an internal bus 22, a network interface 23, a memory 24 and a storage 25, and may also include hardware required for other services. One or more embodiments of the present invention may be implemented based on software, such as the processor 21 reading the corresponding computer program from the storage 25 into the memory 24 and then running it. Of course, in addition to the software implementation, one or more embodiments of the present invention do not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0087] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which may be in the form of a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email transceiver, a game console, a tablet computer, a wearable device or a combination of any of these devices.

[0088] In a typical configuration, a computer includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0089] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0090] Computer-readable media include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0091] The above describes specific embodiments of the present invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0092] In the description of this specification, the description with reference to the terms "an implementation", "an example", "a specific implementation process", "an example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell balancing method, characterized in that: include: Detecting the voltage values ​​of multiple cells of the battery pack to determine whether there are cells that need to be balanced, wherein the cells that need to be balanced are cells whose voltage values ​​are higher than a preset balanced target voltage; When there are cells that need to be balanced, the cells that need to be balanced are renumbered consecutively; During the odd channel balancing start time period, the cells that are numbered odd after being renumbered are discharged and balanced; during the even channel balancing start time period, the cells that are numbered even after being renumbered are discharged and balanced.

2. The battery cell balancing method according to claim 1, characterized in that: Also includes: The voltage values ​​of the multiple cells of the battery pack are detected in real time to determine whether the cell that needs to be balanced has changed.

3. The battery cell balancing method according to claim 1, characterized in that: The re-numbering of the cells that need to be balanced continuously specifically includes: The battery cells that need voltage equalization are renumbered consecutively according to the physical numbers of the battery cells.

4. The battery cell balancing method according to claim 1, characterized in that: The physical number of the battery cell is as follows: According to the physical number of the battery cells in ascending order; or, In order of the physical numbers of the cells from largest to smallest.

5. The battery cell balancing method according to claim 1, characterized in that: The odd channel start time period and the even channel balanced start time period are staggered.

6. The battery cell balancing method according to claim 5, characterized in that: The odd channel equalization start time period has the same time length as the adjacent even channel equalization start time period.

7. A battery pack cell balancing device, characterized in that: include: A cell voltage detection unit, used to detect the voltage values ​​of multiple cells of the battery; a balancing judgment unit, configured to judge whether there are any cells that need balancing based on the voltage value of the cell detected by the cell voltage unit, wherein the cell that needs balancing is a cell whose voltage value is higher than a preset balancing target voltage; a re-numbering unit, configured to re-number the cells that need to be balanced continuously when the balancing judgment unit determines that the cells are yes; The discharge balancing unit is used to perform discharge balancing on the cells that are numbered as odd numbers after being renumbered consecutively during the odd channel balancing opening time period; and to perform discharge balancing on the cells that are numbered as even numbers after being renumbered consecutively during the even channel balancing opening time period.

8. A battery system, characterized in that: include: A battery pack, the battery pack comprising a plurality of battery cells; The battery pack cell balancing device is used to balance the voltages of multiple cells; the battery pack cell balancing device is the battery pack cell balancing device according to claim 7.

9. An electronic device, characterized in that: include: processor; a memory for storing processor-executable instructions; The processor implements the steps in the method of any one of claims 1 to 6 by running the executable instructions.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the steps in the method according to any one of claims 1 to 6 are implemented.

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