A battery equalization method, system, and vehicle

Abstract

A battery equalization method, system and vehicle, comprising: when a feature inflection point of a current reduction charging is identified, if a feature inflection point of a battery cell with the highest voltage and a battery cell with the lowest voltage is not identified or any feature inflection point is not identified, controlling the battery equalization according to a voltage difference of the battery cells. The battery equalization method provided by the embodiments of the present disclosure can control the equalization according to the voltage difference of the battery cells when a feature inflection point of a battery cell with the highest voltage and a battery cell with the lowest voltage is not identified or any feature inflection point is not identified, so that the timing of the battery equalization can be improved, and the reliability and adaptability of the equalization can be improved.

Description

Technical Field

[0001] This disclosure relates to a battery balancing method, system, and vehicle. Background Technology

[0002] In related technologies, characteristic inflection points (the points where voltage changes the fastest) can be found by analyzing the differential of the voltage-capacity curve during battery charging, and cell alignment can be performed based on these inflection points, i.e., inflection point balancing. Inflection point balancing requires a low-current mode, so current reduction processing of the battery is needed during charging to find the inflection point.

[0003] In the above scheme, equilibration will not be performed if no characteristic inflection point is found or too few characteristic inflection points are found. Summary of the Invention

[0004] This disclosure provides a battery balancing method, system, and vehicle to at least partially solve the above-mentioned problems.

[0005] The first aspect of this disclosure provides a battery balancing method, comprising:

[0006] When identifying characteristic inflection points during reduced-current charging, if the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, or if no characteristic inflection points are identified, battery balancing is controlled based on the voltage difference between the battery cells.

[0007] In some embodiments, if the characteristic inflection point of the battery cell with the highest voltage and the lowest voltage is not identified, or if no characteristic inflection point is identified, then controlling the battery equalization based on the voltage difference of the battery cell includes: if no characteristic inflection point is identified, when the battery cell has the lowest voltage during the current reduction charging process, if the difference between the lowest voltage and the lowest voltage of all battery cells at the corresponding time is greater than a first voltage difference, then controlling the battery cell to perform equalization of a first equalization amount.

[0008] In some embodiments, the first voltage difference is 38mV-45mV; and / or the first equalization amount is 3%-6% of the battery capacity.

[0009] In some embodiments, controlling battery balancing based on the voltage difference of the battery cells if no characteristic inflection point of the highest and lowest voltage battery cells is identified, or if no characteristic inflection point is identified, includes controlling at least one of the following balancing methods: if no characteristic inflection point of the highest and lowest voltage battery cells is identified, controlling at least one of the following balancing methods:

[0010] For battery cells that have not identified a feature inflection point, control the first target battery cell to perform equalization of the second equalization amount, wherein the first target battery cell is the battery cell whose voltage difference from the lowest voltage of all battery cells that have not identified a feature inflection point is greater than the second voltage difference.

[0011] For a battery cell with a identified feature inflection point, the second target battery cell is controlled to be balanced to the first balance point. The second target battery cell is the battery cell with the lowest voltage among all the battery cells with identified feature inflection points, and the first balance point is the feature inflection point of the battery cell with the lowest voltage.

[0012] In some embodiments, the second voltage difference is 4mV-7mV, and / or the second equalization amount is 2%-4% of the battery capacity.

[0013] In some embodiments, the method further includes:

[0014] When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the highest voltage but not the characteristic inflection point of the battery cell with the lowest voltage, control to perform at least one of the following equalizations:

[0015] The battery cell with the highest control voltage is used for the third equalization process.

[0016] The remaining battery cells, except for the one with the highest voltage, are controlled to undergo a fourth leveling process.

[0017] In some embodiments, the fourth equilibrium amount is less than the third equilibrium amount.

[0018] In some embodiments, the higher the voltage of the remaining battery cells, the greater their corresponding fourth equalization amount.

[0019] In some embodiments, the third equalization amount is 2%-4% of the battery capacity.

[0020] In some embodiments,

[0021] When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the lowest voltage but not the characteristic inflection point of the battery cell with the highest voltage, control performs at least one of the following equalization operations:

[0022] For a battery cell whose characteristic inflection point is identified, control it to be balanced to the second equalization point, which is the characteristic inflection point of the battery cell with the lowest voltage.

[0023] For battery cells that have not identified a characteristic inflection point, control them to perform the fifth equalization.

[0024] In some embodiments, the fifth equalization amount is 2%-4% of the battery capacity.

[0025] In some embodiments, the method further includes: adjusting the state of charge at the start of descent charging after the battery has been balanced.

[0026] In some embodiments, adjusting the state of charge at the start of reduced-current charging includes at least one of the following:

[0027] When no feature inflection point is identified, the state of charge at the start of current reduction charging is adjusted to the first state of charge, which is the sum or difference between the initial state of charge and the second state of charge.

[0028] When the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, the state of charge at the start of the current reduction charging remains unchanged.

[0029] When the identified feature inflection point includes the feature inflection point of the battery cell with the highest voltage but does not include the feature inflection point of the battery cell with the lowest voltage, the state of charge at the start of the current reduction charging is adjusted to the second state of charge, which is the difference between the initial state of charge and the state of charge corresponding to the minimum value of the fourth equalization quantity.

[0030] When the identified feature inflection points include the feature inflection point of the battery cell with the lowest voltage but not the feature inflection point of the battery cell with the highest voltage, the state of charge at the start of the reduced current charging is adjusted to the third state of charge. The third state of charge is the sum of the initial state of charge and the state of charge corresponding to the minimum value of all equalization quantities. The equalization quantities include the equalization quantity equalized to the second equalization point and the fifth equalization quantity.

[0031] In some embodiments, the second state of charge is 4%-7%.

[0032] The battery balancing method provided in this disclosure can control balancing based on the voltage difference of battery cells when no characteristic inflection points of the highest and lowest voltage cells are identified, or when no characteristic inflection points are identified. This can improve the timing of battery balancing and enhance the reliability and adaptability of balancing.

[0033] This disclosure also provides a battery balancing system, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the methods described above.

[0034] This disclosure also provides an electrical device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the methods described above.

[0035] This disclosure also provides a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implement the steps of any of the methods described above.

[0036] This disclosure also provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of any of the methods described above.

[0037] This disclosure also provides a vehicle that includes the battery balancing system described in any of the preceding claims.

[0038] The above description is merely an overview of the technical solution disclosed herein. In order to better understand the technical means of this disclosure and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this disclosure more apparent and understandable, specific embodiments of this disclosure are described below. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this disclosure. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0040] To gain a more complete understanding of this disclosure and its beneficial effects, the following description will be made in conjunction with the accompanying drawings, wherein the same reference numerals denote the same parts in the following description.

[0041] Figure 1 This is a flowchart illustrating a battery balancing method according to some embodiments;

[0042] Figure 2 This is a flowchart illustrating a battery balancing method according to some other embodiments;

[0043] Figure 3 This is a flowchart illustrating a battery balancing method according to some other embodiments;

[0044] Figure 4 This is a flowchart illustrating a battery balancing method according to some other embodiments. Detailed Implementation

[0045] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the protection scope of this disclosure.

[0046] In the description of this disclosure, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or relative positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. Unless otherwise specified, the above-mentioned orientational descriptions can be flexibly set in practical applications, provided that the relative positional relationships shown in the accompanying drawings are satisfied.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0048] Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0049] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "electrical connection," and "communication" should be interpreted broadly. For example, they can refer to fixed electrical connections, detachable electrical connections, or integral electrical connections. Connections can be direct or indirect through an intermediate medium, and can be internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0050] In embodiments of this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in embodiments of this disclosure is not limited. Functions may be performed in the order shown or discussed, or may be performed substantially simultaneously or in reverse order depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0051] In this disclosure, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this disclosure should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0052] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0053] In some embodiments, such as Figure 1-4 As shown, this disclosure provides a battery balancing method, including:

[0054] When identifying characteristic inflection points during reduced-current charging, if the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, or if no characteristic inflection points are identified, battery balancing is controlled based on the voltage difference between the battery cells.

[0055] The battery balancing method provided in this disclosure can control balancing based on the voltage difference of battery cells when no characteristic inflection points of the highest and lowest voltage cells are identified, or when no characteristic inflection points are identified. This can improve the timing of battery balancing and enhance the reliability and adaptability of balancing.

[0056] Under the two typical failure conditions of "not identifying the characteristic inflection points of the highest and lowest voltage battery cells" or "no characteristic inflection points at all", equalization can be triggered based on the voltage difference between battery cells, without relying on absolute voltage values ​​or characteristic inflection point identification results, thereby achieving redundant compensation for the equalization strategy of related technologies.

[0057] In the above embodiments, by switching the equalization trigger condition from "feature inflection point recognition" to "pressure difference determination", even in scenarios where feature inflection points are misjudged or missed due to large current fluctuations and high sampling noise in fast charging current reduction mode, equalization can still be effectively started, significantly improving the equalization trigger rate, avoiding the continuous accumulation of pressure difference, and thus delaying the capacity decay of the battery pack.

[0058] In some embodiments, such as Figure 3 As shown, if the characteristic inflection point of the battery cell with the highest and lowest voltage is not identified, or if no characteristic inflection point is identified, the battery balancing control based on the voltage difference of the battery cells includes: if no characteristic inflection point is identified, when the battery cell has the lowest voltage during the current reduction charging process, if the difference between the lowest voltage and the lowest voltage of all battery cells at the corresponding time is greater than a first voltage difference, then the battery cell is controlled to perform a first balancing amount.

[0059] In the absence of any characteristic inflection point, equalization can be performed based on the voltage difference. The condition is that the lowest voltage of a single battery cell occurs during the current reduction charging process. The voltage difference is the difference between the lowest voltage of a certain battery cell and the lowest voltage of all battery cells at the same time (the difference at the same moment). If this difference is greater than the first voltage difference, the battery cell can be equalized by the first equalization amount, thereby improving the equalization trigger rate and enhancing the battery equalization effect.

[0060] In some embodiments, the first voltage difference is 38mV-45mV; and / or the first equalization amount is 3%-6% of the battery capacity.

[0061] The first voltage difference can be any suitable value, such as 38mV-45mV, which can effectively enable equalization.

[0062] The first balancing factor is any suitable value, such as 3%-6% of the battery capacity, which can achieve effective balancing and avoid over- or under-balancing.

[0063] In some embodiments, such as Figure 3 and 4 As shown, if the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, or if no characteristic inflection points are identified, then controlling battery balancing based on the voltage difference between the battery cells includes: if the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, controlling at least one of the following balancing methods:

[0064] For battery cells that have not identified a feature inflection point, control the first target battery cell to perform equalization of the second equalization amount, wherein the first target battery cell is the battery cell whose voltage difference from the lowest voltage of all battery cells that have not identified a feature inflection point is greater than the second voltage difference.

[0065] For a battery cell with a identified feature inflection point, the second target battery cell is controlled to be balanced to the first balance point. The second target battery cell is the battery cell with the lowest voltage among all the battery cells with identified feature inflection points, and the first balance point is the feature inflection point of the battery cell with the lowest voltage.

[0066] For cases where the characteristic inflection points of the highest and lowest voltage cells are not identified, equalization can be performed based on voltage differences. Specifically, for all cells where the voltage difference between the highest and lowest voltage is greater than a second voltage difference, a second equalization amount is applied. Here, the lowest voltage refers to the lowest voltage among all cells where the characteristic inflection point is not identified.

[0067] This involves comparing the voltage of all battery cells that have not been identified as having a characteristic inflection point. For the battery cells with a larger voltage (voltage difference greater than the second voltage difference), equalization can be activated, thereby increasing the equalization activation trigger rate and improving the battery equalization effect.

[0068] For battery cells with identified characteristic inflection points, the balance can be controlled to move towards the characteristic inflection point of the battery cell with the lowest voltage, thereby improving the accuracy of the balance.

[0069] The above strategy aligns "cells with characteristic inflection points with the lowest characteristic inflection point, and cells without characteristic inflection points with the lowest characteristic inflection point of the group with inflection points," avoiding the problem of "cells without characteristic inflection points being ignored due to lack of reference." This increases the equalization activation trigger rate and improves the battery equalization effect.

[0070] In some embodiments, the second voltage difference is 4mV-7mV, and / or the second equalization amount is 2%-4% of the battery capacity.

[0071] The second voltage difference can be any suitable value, such as 4mV-7mV, which can effectively enable equalization.

[0072] The second balancing factor is various suitable values, such as 2%-4% of the battery capacity, which can achieve effective balancing to avoid over-balancing or under-balancing.

[0073] In some embodiments, such as Figure 3 As shown, the method also includes:

[0074] When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the highest voltage but not the characteristic inflection point of the battery cell with the lowest voltage, control to perform at least one of the following equalizations:

[0075] The battery cell with the highest control voltage is used for the third equalization process.

[0076] The remaining battery cells, except for the one with the highest voltage, are controlled to undergo a fourth leveling process.

[0077] If the identified feature inflection point includes the feature inflection point of the battery cell with the highest voltage but not the feature inflection point of the battery cell with the lowest voltage, the battery cell with the highest voltage can be controlled to perform the third equalization, and the remaining battery cells can be controlled to perform the fourth equalization, so that all battery cells with identifiable feature inflection points can be equalized.

[0078] Since the characteristic inflection point of the battery cell with the lowest voltage was not identified at this time, more accurate balancing could not be performed. By controlling the third and fourth balancing values, the battery cells with the identified characteristic inflection points can be balanced relatively accurately.

[0079] In some embodiments, the fourth equilibrium quantity is less than the third equilibrium quantity.

[0080] The fourth equalization value can be less than or equal to the third equalization value. In order to improve the accuracy of battery equalization, the fourth equalization value can be less than the third equalization value.

[0081] In some embodiments, the higher the voltage of the remaining battery cells, the greater their corresponding fourth equalization amount.

[0082] That is, the balancing amount can be controlled according to the voltage level of the individual battery cells, thereby improving the accuracy and effectiveness of battery balancing.

[0083] In some embodiments, the third equalization amount is 2%-4% of the battery capacity.

[0084] The third balancing factor is various suitable values, such as 2%-4% of the battery capacity, which can achieve effective balancing to avoid over-balancing or under-balancing.

[0085] In some embodiments, such as Figure 3 As shown,

[0086] When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the lowest voltage but not the characteristic inflection point of the battery cell with the highest voltage, control performs at least one of the following equalization operations:

[0087] For a battery cell whose characteristic inflection point is identified, control it to be balanced to the second balance point, which is the characteristic inflection point of the battery cell with the lowest voltage.

[0088] For battery cells that have not identified a characteristic inflection point, control them to perform the fifth equalization.

[0089] In cases where the identified feature inflection points include the feature inflection point of the battery cell with the lowest voltage but not the feature inflection point of the battery cell with the highest voltage, the battery cells with identifiable feature inflection points can be balanced towards the feature inflection point of the battery cell with the lowest voltage; for battery cells without identifiable feature inflection points, a fifth balancing measure can be applied, thereby achieving balanced control of all battery cells and improving the battery balancing effect.

[0090] In some embodiments, the fifth equalization amount is 2%-4% of the battery capacity.

[0091] The fifth balancing factor is various suitable values, such as 2%-4% of the battery capacity, so as to achieve effective balancing and avoid over-balancing or under-balancing.

[0092] In some embodiments, such as Figure 3As shown, the method also includes: adjusting the state of charge at the start of descent charging after the battery has been balanced.

[0093] Based on the identification of characteristic inflection points, after balancing according to voltage differences, the state of charge at the start of reduced current charging can be adjusted to increase the probability of identifying characteristic inflection points in the next reduced current charging, thereby improving the accuracy and comprehensiveness of battery balancing.

[0094] In some embodiments, such as Figure 3 As shown, adjusting the state of charge at the start of reduced-current charging includes at least one of the following:

[0095] When no characteristic inflection point is identified, the state of charge at the start of current reduction charging is adjusted to the first state of charge, which is the sum or difference between the initial state of charge and the second state of charge.

[0096] When the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, the state of charge at the start of the current reduction charging remains unchanged.

[0097] When the identified feature inflection point includes the feature inflection point of the battery cell with the highest voltage but does not include the feature inflection point of the battery cell with the lowest voltage, the state of charge at the start of the current reduction charging is adjusted to the second state of charge. The second state of charge is the difference between the initial state of charge and the state of charge corresponding to the minimum value of the fourth equalization quantity.

[0098] When the identified characteristic inflection point includes the characteristic inflection point of the battery cell with the lowest voltage but not the characteristic inflection point of the battery cell with the highest voltage, the state of charge at the start of the reduced current charging is adjusted to the third state of charge. The third state of charge is the sum of the initial state of charge and the state of charge corresponding to the minimum value of all equalization quantities. The equalization quantities include the equalization quantity to the second equalization point and the fifth equalization quantity.

[0099] In cases where no characteristic inflection point is identified, the second state of charge can be increased or decreased based on the state of charge at the start of the current reduction charging to increase the probability of identifying the characteristic inflection point during the next current reduction charging, thereby improving the accuracy and comprehensiveness of battery balancing.

[0100] If the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, the state of charge at the start of the reduced current charging remains unchanged. The characteristic inflection points of the battery cells with the highest and lowest voltages may be identified in the next reduced current charging. In this case, the state of charge at the start of the reduced current charging (i.e., the initial state of charge) does not need to be adjusted.

[0101] When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the highest voltage but not the characteristic inflection point of the battery cell with the lowest voltage, the state of charge can be adjusted to the second state of charge. The second state of charge is the difference between the initial state of charge and the state of charge corresponding to the minimum value of the fourth equalization quantity. This can reduce the state of charge at the start of the next current reduction charge, thereby helping to identify the characteristic inflection point of the battery cell with the lowest voltage and improving the accuracy and comprehensiveness of battery equalization.

[0102] Among them, for the fourth equalization quantity of multiple battery cells, the state of charge corresponding to the minimum value can be taken as the reduction amount to improve the accuracy and comprehensiveness of battery equalization.

[0103] When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the lowest voltage but not the characteristic inflection point of the battery cell with the highest voltage, the state of charge at the start of the reduced current charging is adjusted to the third state of charge. The third state of charge is the sum of the initial state of charge and the state of charge corresponding to the minimum value of all equalization quantities. In this case, since all battery cells have been equalized, the minimum value among all equalization quantities (including the equalization quantity equalized to the second equalization point and the fifth equalization quantity) can be taken as the increment to improve the accuracy and comprehensiveness of battery equalization.

[0104] In some embodiments, the second state of charge is 4%-7%.

[0105] The second state of charge can take various suitable values, such as 4%-7%, to improve the accuracy and comprehensiveness of battery balancing.

[0106] like Figure 3 As shown, when the identified characteristic inflection points include both the characteristic inflection point of the battery cell with the lowest voltage and the characteristic inflection point of the battery cell with the highest voltage, this indicates that all battery cells have identified characteristic inflection points, and each battery cell can be balanced to the characteristic inflection point of the battery cell with the lowest voltage, thus achieving an ideal balance state. After balancing, the initial state of charge can be set to a certain state of charge, or current reduction charging can be discontinued to identify characteristic inflection points.

[0107] like Figure 2-4 As shown, the battery balancing method of this disclosure includes:

[0108] When the vehicle is charging, the charging mode is first determined. If it is DC charging, the battery is further determined to be in a good balanced state (which can be determined by the time away from the ideal balanced state). For vehicles that have not reached the ideal balanced state for a long time, the current is reduced.

[0109] During the current reduction process, after charging to 5% capacity, a current reduction request needs to be made within the range max(SOCAh, SOCAh0)+[0%,15%]. Here, SOCAh is the SOC calculated independently based on ampere-hour integration, which is a capacity position standard and is independent of the actual vehicle SOC (this is to prevent the voltage correction SOC from jumping and interfering with the selection of the current reduction position; the current integration error introduced by SOCAh can be ignored within a certain range). SOCAh0 is the starting point of current reduction charging, that is, when the real-time calculated SOCAh reaches the range defined by this value, current reduction begins.

[0110] During the current reduction charging period, the voltage difference between the Vmin of all battery cells and the Vmin of all battery cells at this time is detected. If the voltage difference is greater than, for example, 40mV, the section is marked and recorded (hereinafter referred to as "40mV voltage difference mark"). After the current reduction interval is defined and the current reduction is successfully completed, characteristic inflection point detection is performed within the current reduction interval, and corresponding equalization is performed for different situations.

[0111] For the two cases: no valid inflection point was found, and an inflection point was found but Vmax & Vmin were invalid:

[0112] 1) No inflection point found: No characteristic inflection point was found in any of the battery cells. If any single cell has a "40mV differential voltage mark", then the battery cell in that cell will be balanced at 3-6% and SOCAh0 will be moved.

[0113] 4) Vmax & Vmin are both invalid: that is, at least one intermediate voltage cell has a characteristic inflection point detected in the current reduction range, and neither the highest nor the lowest voltage cell has a characteristic inflection point detected. Then, the cell that has found the inflection point characteristic starts equalization to the lowest voltage cell that has found the inflection point characteristic. If the voltage difference of the cell that has not found the inflection point characteristic is greater than that of the lowest voltage cell that has found the characteristic inflection point characteristic, such as 5mV or more, equalization is started at 3%, and SOCAh0 is not moved.

[0114] The battery balancing method provided in this disclosure can control balancing based on the voltage difference of battery cells when no characteristic inflection points of the highest and lowest voltage cells are identified, or when no characteristic inflection points are identified. This can improve the timing of battery balancing and enhance the reliability and adaptability of balancing.

[0115] This disclosure also provides a battery balancing system, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the above methods.

[0116] This disclosure also provides an electrical device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the above methods.

[0117] This disclosure also provides a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implement the steps of any of the above methods.

[0118] This disclosure also provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of any of the above methods.

[0119] This disclosure also provides a vehicle that includes the battery balancing system described above.

[0120] It should be noted that the aforementioned electrical equipment can be any conventionally power-consuming equipment, such as, but not limited to, controllers, vehicles, skateboard chassis, ships, drones, mobile phones, computers, air conditioners, refrigerators, washing machines, microwave ovens, printers, fax machines, etc.

[0121] The embodiments of this disclosure have been described above with reference to the accompanying drawings. However, this disclosure is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this disclosure without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this disclosure.

Claims

1. A battery balancing method, characterized in that, include: When identifying characteristic inflection points during reduced-current charging, if the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, or if no characteristic inflection points are identified, battery balancing is controlled based on the voltage difference between the battery cells.

2. The battery balancing method according to claim 1, characterized in that, If no characteristic inflection point of the battery cell with the highest and lowest voltage is identified, or if no characteristic inflection point is identified, then controlling battery balancing based on the voltage difference of the battery cells includes: if no characteristic inflection point is identified, when the battery cell reaches its lowest voltage during the current reduction charging process, if the difference between the lowest voltage and the lowest voltage of all battery cells at the corresponding time is greater than a first voltage difference, then controlling the battery cell to perform balancing with a first balancing amount.

3. The battery balancing method according to claim 2, characterized in that, The first voltage difference is 38mV-45mV; and / or the first equalization amount is 3%-6% of the battery capacity.

4. The battery balancing method according to claim 1, characterized in that, If no characteristic inflection point is identified for the battery cells with the highest and lowest voltages, or if no characteristic inflection point is identified, then controlling battery balancing based on the voltage difference between the battery cells includes: if no characteristic inflection point is identified for the battery cells with the highest and lowest voltages, controlling at least one of the following balancing methods: For battery cells that have not identified a feature inflection point, control the first target battery cell to perform equalization of the second equalization amount, wherein the first target battery cell is the battery cell whose voltage difference from the lowest voltage of all battery cells that have not identified a feature inflection point is greater than the second voltage difference. For a battery cell with a identified feature inflection point, the second target battery cell is controlled to be balanced to the first balance point. The second target battery cell is the battery cell with the lowest voltage among all the battery cells with identified feature inflection points, and the first balance point is the feature inflection point of the battery cell with the lowest voltage.

5. The battery balancing method according to claim 4, characterized in that, The second voltage difference is 4mV-7mV, and / or the second equalization amount is 2%-4% of the battery capacity.

6. The battery balancing method according to claim 1, characterized in that, The method further includes: When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the highest voltage but not the characteristic inflection point of the battery cell with the lowest voltage, control to perform at least one of the following equalizations: The battery cell with the highest control voltage is used for the third equalization process. The remaining battery cells, except for the one with the highest voltage, are controlled to undergo a fourth leveling process.

7. The battery balancing method according to claim 6, characterized in that, The fourth equilibrium value is less than the third equilibrium value.

8. The battery balancing method according to claim 6, characterized in that, The higher the voltage of the remaining battery cells, the greater their corresponding fourth equalization quantity.

9. The battery balancing method according to claim 6, characterized in that, The third equalization amount is 2%-4% of the battery capacity.

10. The battery balancing method according to claim 1, characterized in that, When the identified characteristic inflection points include the characteristic inflection point of the battery cell with the lowest voltage but not the characteristic inflection point of the battery cell with the highest voltage, control performs at least one of the following equalization operations: For a battery cell whose characteristic inflection point is identified, control it to be balanced to the second equalization point, which is the characteristic inflection point of the battery cell with the lowest voltage. For battery cells that have not identified a characteristic inflection point, control them to perform the fifth equalization.

11. The battery balancing method according to claim 10, characterized in that, The fifth equilibrium quantity is 2%-4% of the battery capacity.

12. The battery balancing method according to any one of claims 1-11, characterized in that, The method further includes: adjusting the state of charge at the start of reduced-current charging after the battery is balanced.

13. The battery balancing method according to claim 12, characterized in that, The adjustment of the state of charge at the start of the current-reducing charge includes at least one of the following: If no characteristic inflection point is identified, the state of charge at the start of current reduction charging is adjusted to the first state of charge, which is the sum or difference between the initial state of charge and the second state of charge, wherein the second state of charge is 4%-7%; When the characteristic inflection points of the battery cells with the highest and lowest voltages are not identified, the state of charge at the start of the current reduction charging remains unchanged. When the identified feature inflection point includes the feature inflection point of the battery cell with the highest voltage but does not include the feature inflection point of the battery cell with the lowest voltage, the state of charge at the start of the current reduction charging is adjusted to the second state of charge, which is the difference between the initial state of charge and the state of charge corresponding to the minimum value of the fourth equalization quantity. When the identified feature inflection points include the feature inflection point of the battery cell with the lowest voltage but not the feature inflection point of the battery cell with the highest voltage, the state of charge at the start of the reduced current charging is adjusted to the third state of charge. The third state of charge is the sum of the initial state of charge and the state of charge corresponding to the minimum value of all equalization quantities. The equalization quantities include the equalization quantity equalized to the second equalization point and the fifth equalization quantity.

14. A battery balancing system, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-13.

15. A vehicle, characterized in that, include: The battery balancing system as described in claim 14.

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